meropenem and Cystic-Fibrosis

Topics: Anti-Bacterial Agents; Carbapenems; Cystic Fibrosis; Doripenem; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa

Antibiotic therapy is one of the main treatments for cystic fibrosis (CF). It aims to eradicate bacteria during early infection, calms down the inflammatory process, and leads to symptom resolution of pulmonary exacerbations. CF can modify both the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of antibiotics, therefore specific PK/PD endpoints should be determined in the context of CF. Currently available data suggest that optimal PK/PD targets cannot be attained in sputum with intravenous aminoglycosides. Continuous infusion appears preferable for β-lactam antibiotics, but optimal concentrations in sputum are unlikely to be reached, with some possible exceptions such as meropenem and ceftolozane. Usual doses are likely suboptimal for fluoroquinolones and linezolid, whereas daily doses of 45-60 mg/kg and 200 mg could be convenient for vancomycin and doxycycline, respectively. Weekly azithromycin doses of 22-30 mg/kg could also be appropriate for its anti-inflammatory effect. The difficulty with achieving optimal concentrations supports the use of combined treatments and the inhaled administration route, as very high local concentrations, concomitantly with low systemic exposure, can be obtained with the inhaled route for aminoglycosides, colistin, and fluoroquinolones, thus minimizing the risk of toxicity.

Topics: Aminoglycosides; Anti-Bacterial Agents; Cystic Fibrosis; Humans; Linezolid; Meropenem

Burkholderia gladioli is an unusual organism that has become increasingly responsible for infections in patients who are immunosuppressed, including patients who have undergone solid organ transplantation. This article presents a patient in whom a mediastinal mass due to Burkholderia gladioli developed after lung transplantation. A review of the literature is also presented.

Topics: Abscess; Adult; Anti-Bacterial Agents; Burkholderia gladioli; Burkholderia Infections; Combined Modality Therapy; Cystic Fibrosis; Diagnosis, Differential; Drainage; Drug Therapy, Combination; Humans; Infusions, Intravenous; Lung Transplantation; Male; Mediastinal Diseases; Meropenem; Opportunistic Infections; Postoperative Complications; Thienamycins; Tobramycin; Tomography, X-Ray Computed

Meropenem is a new beta-lactam carbapenem antibiotic that appears to be promising in the treatment of hospitalized infants and children with serious infections. It has broad-spectrum activity against microorganisms, including most of the major aerobic (gram-negative and gram-positive) and anaerobic pathogens that cause serious bacterial infections in neonates and children. In addition, its pharmacokinetic profile makes possible parenteral administration every 8 hours. Several studies have demonstrated that meropenem is an effective and safe treatment for infants and children with serious pediatric infections (e.g., urinary tract infections, pneumonia, sepsis, intraabdominal infections, and skin and soft-tissue infections), bacterial meningitis, and cystic fibrosis. The results of further studies of the use of meropenem in the treatment of high-risk seriously ill infants and children are awaited with interest.

Topics: Anti-Bacterial Agents; Bacterial Infections; Child; Child, Preschool; Clinical Trials as Topic; Cystic Fibrosis; Female; Hospitalization; Humans; Infant; Infant, Newborn; Male; Meningitis, Bacterial; Meropenem; Microbial Sensitivity Tests; Thienamycins

The survival of cystic fibrosis patients has improved through an aggressive, multidisciplinary approach to the therapy of pulmonary sepsis. Intravenous antibiotics play a major role in the care of cystic fibrosis patients, even though it is not possible to achieve persistent bacterial eradication due to the complex microbiology and pathology of these patients. The most important pathogen in older patients is Pseudomonas aeruginosa. The increasing incidence of Pseudomonas cepacia, strains of which can be highly resistant to many antibiotics, also represents an important challenge to the efficacy of antibiotic therapy. Choice of appropriate antimicrobial therapy is hampered by the fact that a single patient may harbour several different pseudomonas phenotypes with variable resistance patterns. Carbapenem antibiotics possess a wide range of activity against most Gram-negative and Gram-positive bacteria and are therefore a useful addition to the antimicrobial armamentarium available to the clinician. The new carbapenem meropenem is well tolerated at high doses by both children and adults. Results from a comparative trial against ceftazidime suggests that meropenem has a place in the management of cystic fibrosis.

Topics: Adult; Ceftazidime; Child; Child, Preschool; Clinical Trials as Topic; Cystic Fibrosis; Humans; Meropenem; Pneumonia, Bacterial; Pseudomonas Infections; Thienamycins

In cystic fibrosis (CF), conventional antibiotic susceptibility results correlate poorly with clinical outcomes. We hypothesized that biofilm testing would more accurately reflect the susceptibilities of bacteria infecting CF airways.. A multicenter randomized pilot trial was conducted to assess the efficacy and safety of using biofilm susceptibility testing of Pseudomonas aeruginosa sputum isolates to guide antibiotic regimens for chronic airway infections in clinically stable adolescent and adult CF patients. Thirty-nine participants were randomized to biofilm or conventional treatment groups; 14-day courses of two antibiotics were selected according to an activity-based algorithm using the corresponding susceptibility results.. Of the agents tested, meropenem was most active against biofilm-grown bacteria, and was included in regimens for about half of each study group. For 19 of 39 randomized participants, randomization to the other study group would not have changed the antibiotic classes of the assigned regimen. Study groups were comparable at baseline, and had similar mean decreases in bacterial density, measured in log(10) colony forming units per gram of sputum (biofilm, -2.94 [SD 2.83] vs. conventional, -3.27 [SD 3.09]), and mean increases in forced expiratory volume in 1 sec, measured in liters (0.18 [SD 0.20] vs. 0.12 [SD 0.22]).. In this pilot study, antibiotic regimens based on biofilm testing did not differ significantly from regimens based on conventional testing in terms of microbiological and clinical responses. The predictive value of biofilm testing may nonetheless warrant evaluation in an adequately powered clinical trial in younger CF patients or those experiencing acute pulmonary exacerbation.

Topics: Adult; Anti-Bacterial Agents; Biofilms; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Forced Expiratory Flow Rates; Humans; Lung; Male; Meropenem; Microbial Sensitivity Tests; Pilot Projects; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Tract Infections; Sputum; Thienamycins; Young Adult

Cystic fibrosis (CF) is characterized by chronic bacterial broncho-pulmonary infection. Although intravenous (i.v.) antibiotic therapy is regarded as standard treatment in CF, only few randomised trials comparing different antibiotic compounds exist.. We report on a prospective multicenter interventional trial of i.v. meropenem (120 mg/kg/day) or i.v. ceftazidime (200-400 mg/kg/day), each administered together with i.v. tobramycin (9-12 mg/kg/day). Outcome measures were changes in lung function, microbiological sputum burden and blood inflammatory marker. Liver and renal function values were measured to assess safety.. One hundred eighteen patients (59/59) were included into the study with the following indications: first infection of P. aeruginosa (n=6), acute pulmonary exacerbation (n=34) and suppression therapy of chronic P. aeruginosa colonization (n=78). Both treatments improved lung function measures, bacterial sputum burden and CRP levels with no differences between treatment groups observed. A significant higher elevation for alkaline phosphatase (p<0.0001) was observed for patients in the meropenem/tobramycin group.. i.v. antibiotic therapy in CF patients with meropenem/tobramycin is as effective as with ceftazidime/tobramycin regarding lung function, microbiological sputum burden and systemic inflammatory status. Hepato-biliary function should be monitored carefully during i.v. treatment, possibly important in CF patients with pre-existing liver disease.

Topics: Adolescent; Anti-Bacterial Agents; Bacterial Infections; C-Reactive Protein; Ceftazidime; Child; Child, Preschool; Cystic Fibrosis; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Infant; Infant, Newborn; Infusions, Intravenous; Male; Meropenem; Prospective Studies; Thienamycins; Tobramycin; Treatment Outcome

Meropenem (in combination with amikacin) was used in the treatment of children and adolescents with mucoviscidosis and severe exacerbation of bronchopulmonary affections. The drug showed satisfactory clinical and moderate bacteriological effects (48.3%) as dependent on the severity and duration of the disease and the microbial flora. Meropenem was well tolerated: no side effects were observed during the treatment, whereas it was used in high doses (60-105 mg/kg daily).

Topics: Amikacin; Anti-Bacterial Agents; Bronchopneumonia; Child; Cystic Fibrosis; Drug Therapy, Combination; Female; Humans; Male; Meropenem; Thienamycins; Treatment Outcome

Cystic fibrosis (CF) is characterized by chronic pulmonary infection with acute pulmonary exacerbations (APEs) requiring IV antibiotic treatment. We report on a blinded comparative trial of IV meropenem (40 mg/kg to 2 g q8h) or ceftazidime (5 mg/kg to 2 g q8h), each of which was administered with IV tobramycin (at a serum peak of > or = 8 microg/mL and a trough of < 2 microg/mL), as treatment for CF patients with APEs.. Patients who were > or = 5 years of age who were infected with ceftazidime-susceptible Pseudomonas aeruginosa were stratified by lung function and randomized to treatment with meropenem/tobramycin or ceftazidime/tobramycin. Patients infected with Burkholderia cepacia complex or ceftazidime-resistant P aeruginosa were assigned to receive open-label meropenem/tobramycin. Clinical response was assessed by spirometry to determine the change in percent predicted FEV1 and by a clinical acute change score (ACS).. One hundred two patients were randomized to meropenem/tobramycin (n = 50) or ceftazidime/tobramycin (n = 52). Nineteen patients received open-label meropenem/tobramycin. FEV1 was improved at the end of treatment (EOT) with meropenem/tobramycin (mean [+/- SD] increase, 38.8 +/- 52.3%) and with ceftazidime/tobramycin (mean increase, 29.4 +/- 35.1%; p < 0.0001 vs baseline values). The proportion of patients with > or = 15% relative increase from baseline FEV1 (satisfactory response) at day 7 was 62% for the meropenem/tobramycin group and 44% for the ceftazidime/tobramycin group (p = 0.04). The median time to FEV1 response was 4 days for meropenem/tobramycin therapy vs 6 days for ceftazidime/tobramycin therapy. Similarly, FEV1 improved in the open-label group (mean increase, 12.5 +/- 25.7%; p = 0.05). ACS improved in all three groups at EOT (p < 0.0001 vs baseline values).. Therapy with both meropenem/tobramycin and ceftazidime/tobramycin improved pulmonary and clinical status and reduced sputum bacterial burden in CF patients with APEs. A larger proportion of patients receiving meropenem/tobramycin therapy demonstrated a satisfactory FEV1 response at day 7. Resistant P aeruginosa emerged infrequently during treatment with both regimens.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Burkholderia cepacia; Burkholderia Infections; Ceftazidime; Child; Child, Preschool; Cystic Fibrosis; Disease Progression; Drug Therapy, Combination; Forced Expiratory Volume; Humans; Meropenem; Middle Aged; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Function Tests; Sputum; Thienamycins; Tobramycin

Meropenem is commonly used to treat lung infections in adults with cystic fibrosis (CF). Although continuous infusion is the ideal method to maximize the pharmacodynamic properties of this betalactam antibiotic, meropenem is stable for only approximately 4 to 6 hours at room temperature, and its pharmacokinetic (PK) properties, when administered by continuous infusion to patients with CF, are largely unknown.. This study was undertaken to determine the PK properties and stability of meropenem when administered to adults with CF by a continuous ambulatory drug-delivery infusion pump stored in a cold pouch between 2 freezer packs.. This open-label, multidose, randomized, crossover PK study was conducted at the Clinical Research Center at Hartford Hospital (Hartford, Connecticut). Adults aged > or = 18 years with CF were eligible. Study participants were randomized to receive meropenem 125 mg/h or 250 mg/h (equivalent to 3 g and 6 g, respectively, over 24 hours) by continuous IV infusion for 12 hours. Serum samples were collected throughout the infusion and then for 6 hours after infusion to determine the PK properties (volume of distribution [V(d)], elimination rate constant, total body clearance [CL], terminal half-life [t 1/2], and steady-state concentration [C(ss)]). Serum meropenem concentrations were assayed using high-performance liquid chromatography, and PK profiles were determined using compartmental analysis. Meropenem stability was ascertained by sampling the drug directly from the infusion pump at prespecified time points. Meropenem tolerability was assessed throughout the study by questioning subjects on how they felt. In addition, laboratory values of serum chemistries and liver enzymes were compared with baseline values.. Seven adult volunteers with CF (4 women, 3 men; mean [SD] age, 27 [10] years [range, 19-46 years]) participated in the study. Mean (SD) C(ss) values were 8.31 (0.68) mg/L and 18.50 (3.31) mg/L for the 125-mg/h and 250-mg/h infusion rates, respectively. V(d), CL, and t 1/2 were dose independent and similar between the 2 infusion rates. Meropenem stability was maintained over 12 and 24 hours. Meropenem by continuous infusion was well tolerated. One patient complained of a headache during the study.. In this study of adults with CF, meropenem infusion rates of 125 mg/h and 250 mg/h provided serum drug concentrations greater than the minimum inhibitory concentration for pathogens considered meropenem susceptible (< or =4 microg/mL) and intermediately resistant (8 microg/mL), respectively.

Topics: Adult; Anti-Bacterial Agents; Cross-Over Studies; Cystic Fibrosis; Dose-Response Relationship, Drug; Drug Stability; Female; Humans; Infusions, Intravenous; Male; Meropenem; Middle Aged; Outpatients; Thienamycins; Time Factors

Clinical efficacy of meropenem (meronem, Zeneca), a new carbapenem, was studied in the treatment of 4 adult patients with mucoviscidosis. The drug was administered as intravenous infusions 3 times a day in a daily dose of 60 mg/kg body weight for 10 days. A positive clinical effect was observed in 3 patients and in 1 patient stabilization of the clinical state was recorded. A significant decrease in the titre of the Pseudomonas aeruginosa colonies in 2 patients and that of the P. aeruginosa mucosa colonies in 3 patients was bacteriologically confirmed. Good tolerance and no side effects of meropenem in the doses used were stated. The study showed that meropenem may be recommended for the treatment of adult patients with mucoviscidosis.

Topics: Adult; Cystic Fibrosis; Female; Humans; Infusions, Intravenous; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Radiography; Thienamycins; Treatment Outcome

Cystic fibrosis patients (children and young adults) with Pseudomonas spp. chest infections were treated with meropenem or ceftazidime. This study was the first to investigate the use of meropenem in cystic fibrosis. Meropenem was well tolerated with only transient elevations of serum transaminases. No patient experienced nausea and vomiting, even when meropenem was administered as a bolus injection. This allowed home therapy to be used. Meropenem appeared to be at least as active as ceftazidime even at the low doses used. Patients showed a greater improvement in respiratory function on meropenem than ceftazidime. Only one patient (out of 60 courses) failed to respond to meropenem (98% success rate) compared with two failures out of 21 episodes with ceftazidime (90% success rate). There was little emergence of resistance to meropenem even though some patients were treated up to eight times over a 2 year period.

Topics: Adolescent; Adult; Carbapenems; Ceftazidime; Cephalosporins; Child, Preschool; Cystic Fibrosis; Drug Tolerance; Humans; Liver; Meropenem; Microbial Sensitivity Tests; Nausea; Pseudomonas Infections; Spirometry; Sputum; Thienamycins; Transaminases; Treatment Outcome; Vomiting

The

Topics: Anti-Bacterial Agents; Ceftazidime; Colistin; Cystic Fibrosis; Drug Synergism; Humans; Meropenem; Microbial Sensitivity Tests

Topics: Achromobacter; Anti-Bacterial Agents; Cystic Fibrosis; Humans; Meropenem; Microbial Sensitivity Tests; Piperacillin; Tazobactam

Antibiotic allergy is a big problem that may affect the treatment and life quality of patients with cystic fibrosis (CF).. To evaluate predictive factors for confirmed antibiotic hypersensitivity in children with CF.. In this case-controlled study, we examined 15 patients with CF who had been confirmed with antibiotic allergy. Additionally, we included a control group of age- and gender-matched 45 CF patients with no antibiotic allergy. The diagnosis of antibiotic allergy was confirmed in the presence of a compatible history and a positive response in the drug skin test or provocation test. Multiple drug hypersensitivity was classified according to the temporal relationship of antibiotics: (i) distant, (ii) simultaneous, and (iii) sequential. The data were analyzed by conditional logistic regression.. β-lactam allergy was confirmed in eight patients (ceftazidime n = 5, piperacillin-tazobactam n = 3) and non-β-lactam allergy was confirmed in two patients (ciprofloxacin n = 1, azithromycin n = 1). Additionally, multiple drug hypersensitivity in five patients (distant n = 4, sequential n = 1), among whom two patients showed hypersensitivity against ceftazidime/piperacillin-tazobactam+ ciprofloxacin/levofloxacin, two patients showed hypersensitivity against ceftazidime+ ciprofloxacin n = 2, and one patient showed hypersensitivity against piperacillin-tazobactam+ amikacin+ trimethoprim-sulfamethoxazole. All patients (n = 13) with confirmed β-lactam allergy were meropenem tolerant. Multivariate analysis indicated that immediate reactions (, p < 0.001) and allergic evaluation in the first six months after the reaction (p = 0.036) were significant risk factors for the prediction of antibiotic hypersensitivity.. Beta-lactam antibiotic allergy is the most commonly confirmed drug allergy in children with CF. However, unlike normal children, ceftazidime and piperacillin-tazobactam account for the majority.

Topics: Amikacin; Anti-Bacterial Agents; Azithromycin; Case-Control Studies; Ceftazidime; Child; Ciprofloxacin; Cystic Fibrosis; Drug Hypersensitivity; Humans; Levofloxacin; Meropenem; Piperacillin; Retrospective Studies; Tazobactam; Trimethoprim, Sulfamethoxazole Drug Combination

We are writing this letter to provide an update of published information on antibiotics for cystic fibrosis (CF) pulmonary exacerbations to the State of the Art articles by Zobell et al. Information on meropenem-vaborbactam and cefiderocol were not available when the original articles were published. These new antibiotics, approved in 2017 and 2019, possess antipseudomonal properties like the other carbapenems and cephalosporins in the original articles however, existing literature refers to their use for other less common bacteria. As patients with CF age, the microorganisms in their bacterial cultures change and some can colonize multiple or uncommon bacterial species including, Burkholderia, Achromobacter, and Stenotrophomonas spp. In 2019, these nonlactose fermenting bacterial species made up for approximately 15% of respiratory microorganisms cultured in pediatric patients. Though infrequent, compared to Staphylococcus aureus or Pseudomonas aeruginosa, these bacteria are opportunistic pathogens and patients at the highest risk for these infections include those with CF. Like other Gram negative bacteria, Burkholderia, Achromobacter, and Stenotrophomonas spp., are frequently drug resistant and can make treatment extremely challenging, thus it is crucial that data for treatment of these less common pathogens be evaluated.

Topics: Anti-Bacterial Agents; Boronic Acids; Cefiderocol; Cephalosporins; Child; Cystic Fibrosis; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Meropenem

Achromobacter xylosoxidans is an emerging pathogen in cystic fibrosis (CF). Relatively little is known about its clinical impact and optimal management. In the present study, the in vitro bactericidal activities of meropenem, either alone or in combination with colistin, levofloxacin, or chloramphenicol, were assessed using A. xylosoxidans strains isolated from CF patients. The synergistic interactions of these combinations were also investigated.. Minimal inhibitory concentrations (MICs) were determined by microbroth dilution. Bactericidal and synergistic effects of the tested antibiotic combinations were assessed by using the time-kill curve technique.. Based on the time-kill curves, we found that meropenem-colistin combinations have bactericidal and synergistic activities for 24 h against A. xylosoxidans strains, both at 1 × MIC and 4 × MIC. Although synergistic interactions were seen with meropenem-levofloxacin combinations, no bactericidal interactions were observed. Additionally, the meropenem-chloramphenicol combinations were found to be neither bactericidal nor synergistic. No antagonism was observed with any combination tested.. This study's findings could have important implications for empirical or combination antimicrobial therapy with tested antibiotics.

Topics: Achromobacter denitrificans; Anti-Bacterial Agents; Chloramphenicol; Colistin; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Humans; Levofloxacin; Meropenem

Cystic fibrosis is associated with significant morbidity and early mortality due to recurrent acute and chronic lung infections. The chronic use of multiple antibiotics without pathogen eradication increases the possibility of extensive drug resistance or even pan-drug resistance (PDR). It is imperative that new or alternative treatment options be explored. We present a clinical case of a 10-year-old female cystic fibrosis patient, infected with a PDR Achromobacter spp. She was treated with cefiderocol, meropenem/vaborbactam, and bacteriophage therapy (Ax2CJ45ϕ2) during two separate admissions in an attempt to clear her infection and restore baseline pulmonary function. The Centers for Disease Control and Prevention confirmed antibiotic susceptibilities, which showed resistance to both cefiderocol and meropenem/vaborbactam. However, after using all three agents concomitantly during the second treatment course, our patient's pulmonary function improved dramatically, and the Achromobacter spp. could not be isolated from sputum samples obtained 8 and 16 weeks after completion of therapy. Overall, the treatment regimen consisting of cefiderocol, meropenem/vaborbactam, and bacteriophage was safe and well-tolerated in our patient.

Topics: Achromobacter; Anti-Bacterial Agents; Bacteriophages; Boronic Acids; Cefiderocol; Cephalosporins; Child; Combined Modality Therapy; Cystic Fibrosis; Drug Combinations; Drug Resistance, Bacterial; Drug Resistance, Multiple; Female; Gram-Negative Bacterial Infections; Heterocyclic Compounds, 1-Ring; Humans; Meropenem

Chronic respiratory infection with

Topics: Administration, Inhalation; Administration, Oral; Anti-Bacterial Agents; Burkholderia cenocepacia; Burkholderia Infections; Child, Preschool; Cystic Fibrosis; Humans; Levofloxacin; Male; Maxillary Sinus; Maxillary Sinusitis; Meropenem; Nasal Lavage; Otorhinolaryngologic Surgical Procedures; Penicillins; Trimethoprim, Sulfamethoxazole Drug Combination

We tested the

Topics: Achromobacter; Anti-Bacterial Agents; beta-Lactamase Inhibitors; Boronic Acids; Burkholderia; Cystic Fibrosis; Humans; Meropenem; Microbial Sensitivity Tests; Piperacillin; Pseudomonas aeruginosa; Stenotrophomonas; Stenotrophomonas maltophilia; Tazobactam

In the lungs of cystic fibrosis patients, Pseudomonas aeruginosa is exposed to a myriad of antibiotics leading to alterations in antibiotic susceptibility. This study identifies mutations resulting in hypersusceptibility in isogenic mutants of a P. aeruginosa clinical isolate, PA34.. PA34 was exposed to subinhibitory concentrations of doripenem or meropenem during growth to mid-log phase. Antibiotic susceptibility of surviving colonies was determined by agar dilution. Two carbapenem-resistant colonies hypersusceptible to non-carbapenem antibiotics were selected for further analysis. Antibiotic resistance gene expression was evaluated by RT-rtPCR and OprD production by SDS-PAGE. PA34 and isogenic mutants were evaluated with whole genome sequencing. Sequence variants were confirmed by Sanger sequencing, and cognate genes in eight carbapenem-resistant clinical isolates hypersusceptible to non-carbapenem antibiotics were sequenced. Lipopolysaccharide preparations of PA34 and hypersusceptible mutants were evaluated with ProQ-Emerald stain.. Isogenic mutants showed 4- to 8-fold MIC increase for imipenem, meropenem, and doripenem. However, they were hypersusceptible (≥4-fold MIC decrease) to aminoglycosides, fluoroquinolones, and non-carbapenem β-lactams. Expression of ampC or mex-opr efflux pumps was unchanged, but OprD production was decreased. Mutations causing Q86H AlgU and G77C LptG amino acid substitutions and nonsense mutations within OprD were observed in both mutants. Lipopolysaccharide modifications were observed between isogenic mutants and PA34. Non-synonymous mutations in LptF or LptG were observed in 6/8 hypersusceptible clinical isolates resistant to carbapenem antibiotics.. Evaluation of hypersusceptible mutants identified the association between lptG and a hypersusceptible phenotype. Modifications in lipopolysaccharide profiles suggests LptG modification interferes with lipopolysaccharide transport and contributes to hypersusceptibility.

Topics: Anti-Bacterial Agents; ATP-Binding Cassette Transporters; Cell Membrane; Codon, Nonsense; Cystic Fibrosis; Doripenem; Drug Resistance, Bacterial; Electrophoresis, Polyacrylamide Gel; Humans; Imipenem; Lipopolysaccharides; Meropenem; Microbial Sensitivity Tests; Mutation, Missense; Permeability; Porins; Pseudomonas aeruginosa; Pseudomonas Infections; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Whole Genome Sequencing

Antibiotic therapy is of vital importance for the control of infectious exacerbations in cystic fibrosis (CF) patients. However, very little is known regarding the fraction of systemically administered antibiotics reaching the lower respiratory tract secretions. We developed and validated a method to measure the concentrations of piperacillin, ceftazidime, meropenem and aztreonam in CF sputum, and present the validation data.. Ultra-performance LC coupled to tandem MS was used. A single sample can be measured in 2.5 min with multiple reaction monitoring in positive electrospray ionization mode. Deuterated internal standards were used and a concentration range of 0.7-160 mg/L was covered. The method was validated according to the EMA guideline on analytical method validation.. The boundaries within which a reliable measurement in CF sputum can be performed were determined. A few constraints are linked to the instability of the antibiotics in sputum. Piperacillin showed limited stability at room temperature and during freeze-thaw cycles. Autosampler instability was observed after 15 h for aztreonam at low concentrations.. The method allows a reliable measurement of the selected antibiotics, if precautions are taken regarding the limited stability of piperacillin at room temperature. Due to freeze-thaw instability, piperacillin should always be analysed on the day of sampling. Quick review of the analytical data and reanalysis are needed as low concentrations of aztreonam are not stable in the autosampler.

Topics: Anti-Bacterial Agents; Aztreonam; Ceftazidime; Chromatography, High Pressure Liquid; Cystic Fibrosis; Humans; Meropenem; Piperacillin; Sputum; Tandem Mass Spectrometry; Thienamycins

This case series explored the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of meropenem (MEM) in adult cystic fibrosis (CF) patients hospitalized for a pulmonary exacerbation. From January 2015 to June 2016, all adult patients with cystic fibrosis (CF) and chronic pulmonary infection due to meropenem (MEM)-susceptible/intermediate Pseudomonas aeruginosa who received at least 48 h of MEM as an extended 3-hour infusion for treating a pulmonary exacerbation were enrolled. MEM plasma concentrations were determined by high-performance liquid chromatography. Six adult CF patients with a median age of 47 years were included in the study. MEM showed a high Vd (mean 45.98 L, standard deviation [SD] ±34.45). A minimal PK/PD target of 40% T > minimum inhibitory concentration (MIC) with respect to the MEM MIC of P. aeruginosa strains isolated from sputum during exacerbation was achieved in 5/6 patients (83%). MEM failed to achieve this target only in one patient, whose strain showed the highest MEM MIC in our cohort (8 mg/L). In all patients, MEM was well tolerated, and no adverse events were reported. In conclusion, high-dose, extended-infusion MEM during pulmonary exacerbation showed a high Vd in six adult CF patients with high median age, and was well tolerated.

Topics: Adult; Anti-Bacterial Agents; Cystic Fibrosis; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Resistance, Bacterial; Female; Humans; Male; Meropenem; Microbial Sensitivity Tests; Middle Aged; Pseudomonas aeruginosa; Pseudomonas Infections; Thienamycins

Pseudomonas aeruginosa is the predominant pathogen responsible of chronic colonization of the airways in cystic fibrosis (CF) patients. There are few European data about antibiotic susceptibility evolution of P aeruginosa in CF patients.. The aim of this study is to evaluate the evolution of antibiotic resistance in the period 2010-2013 in CF patients chronically colonized by P aeruginosa and to highlight the characteristics of this evolution in patients younger than 20 years.. Clinical and microbiological data were extracted from two electronic databases and analyzed. Antibiotic resistance was defined according to European Committee of Antimicrobial Susceptibility Testing for levofloxacin, ciprofloxacin, meropenem, amikacin and ceftazidime. The between-group comparison was drawn with the Chi-square test for proportions, with the T-test for unpaired samples for normally distributed data and with Mann-Whitney test for non-normally distributed data. Significancy was defined by P < .05.. Fifty-seven CF patients, including thirteen subjects aged less than 20 years, were enrolled. P.. aeruginosa antibiotic sensitivity decreased significantly for fluoroquinolones, mainly in patients aged <20 years, while it increased for amikacin and colistin. The analysis of minimum inhibitory concentration confirmed these trends. In pediatric patients treated with more than three antibiotic cycles per year, greater resistance was found, except for amikacin and colistin.. An evolution in P aeruginosa antibiotic resistances is observed in the 4-year period studied. Responsible and informed use of antibiotics is mandatory in CF.

Topics: Adolescent; Adult; Amikacin; Anti-Bacterial Agents; Ceftazidime; Child; Ciprofloxacin; Cystic Fibrosis; Drug Resistance, Microbial; Female; Humans; Levofloxacin; Longitudinal Studies; Male; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Young Adult

Patient is a 6-year-old male with CF, MRSA colonization, and pancreatic insufficiency that presented with worsening ppFEV1 and systemic symptoms despite multiple interventions. BAL grew NTM, Stenotrophomonas maltophilia, and Inquilinus limosus, a rare organism found in patients with CF.. I. limosus treatment was deferred. Despite treatment of other pathogens, symptoms worsened. I. limosus was targeted with meropenem, amikacin, and ciprofloxacin along with clindamycin for MRSA colonization. Within weeks, symptoms had resolved with ppFEV1 improvement.. This case discusses the importance of a rare organism in the CF population. Targeting I. limosus was key to recovery, revealing its potential pathogenicity.

Topics: Amikacin; Anti-Bacterial Agents; Child; Ciprofloxacin; Clindamycin; Cystic Fibrosis; Gram-Negative Bacterial Infections; Humans; Male; Meropenem; Methicillin-Resistant Staphylococcus aureus; Rhodospirillaceae; Stenotrophomonas maltophilia; Virulence

Burkholderia cepacia complex (Bcc) infection, associated with cystic fibrosis (CF) is intrinsically multidrug resistant to antibiotic treatment making eradication from the CF lung virtually impossible. Infection with Bcc leads to a rapid decline in lung function and is often a contraindication for lung transplant, significantly influencing morbidity and mortality associated with CF disease. Standard treatment frequently involves antibiotic combination therapy. However, no formal strategy has been adopted in clinical practice to guide successful eradication. A new class of direct-acting, large molecule polycationic glycopolymers, derivatives of a natural polysaccharide poly-N-acetyl-glucosamine (PAAG), are in development as an alternative to traditional antibiotic strategies. During treatment, PAAG rapidly targets the anionic structural composition of bacterial outer membranes. PAAG was observed to permeabilize bacterial membranes upon contact to facilitate potentiation of antibiotic activity. Three-dimensional checkerboard synergy analyses were used to test the susceptibility of eight Bcc strains (seven CF clinical isolates) to antibiotic combinations with PAAG or ceftazidime. Potentiation of tobramycin and meropenem activity was observed in combination with 8-128 μg/mL PAAG. Treatment with PAAG reduced the minimum inhibitory concentration (MIC) of tobramycin and meropenem below their clinical sensitivity breakpoints (≤4 μg/mL), demonstrating the ability of PAAG to sensitize antibiotic resistant Bcc clinical isolates. Fractional inhibitory concentration (FIC) calculations showed PAAG was able to significantly potentiate antibacterial synergy with these antibiotics toward all Bcc species tested. These preliminary studies suggest PAAG facilitates a broad synergistic activity that may result in more positive therapeutic outcomes and supports further development of safe, polycationic glycopolymers for inhaled combination antibiotic therapy, particularly for CF-associated Bcc infections.

Topics: Acetylglucosamine; Anti-Bacterial Agents; Burkholderia cepacia complex; Cystic Fibrosis; Drug Resistance, Bacterial; Humans; Meropenem; Microbial Sensitivity Tests; Thienamycins; Tobramycin

Burkholderia sp. infections are extremely complex in cystic fibrosis (CF) patients, especially considering the lack of knowledge regarding its behavior, its relationship with prognosis, as well as its transmissibility and multidrug resistance features. This study evaluated the frequency of chronic infection by Burkholderia, using microbiological and clinical data. Ninety-eight patients with CF attended from July 2011 to April 2014 in a Brazilian reference hospital were included. Antimicrobial activity, molecular epidemiology, Shwachman score, body mass index, exacerbations, and lung function were analyzed. Nine patients had chronic colonization, and all of them showed preserved pulmonary function levels, body mass index, and Shwachman score. Meropenem was the most effective antibiotic; however, divergent results were shown by other studies. Cross-contamination may have occurred in only two unrelated patients of different ages, who were colonized by B. vietnamiensis, which does not occur frequently. Twelve new sequence types (STs) were identified and three STs have presented intercontinental distribution. None of the patients presented known epidemic strains. In conclusion, a relatively low number of patients with chronic colonization and suspected cross-infection were identified. Different from other studies that have found CF patients chronically colonized with Burkholderia sp. having a greater deterioration of lung function, more frequent antibiotic therapy, and increased mortality, in the current study, the patients showed good clinical outcomes and favorable options for antibiotics therapy. This study also updated the epidemiological database, which facilitates the multicentric collaborative analysis and assists in the control of global infection by these pathogens.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Brazil; Burkholderia cepacia complex; Burkholderia Infections; Ceftazidime; Child; Child, Preschool; Cross Infection; Cystic Fibrosis; Electrophoresis, Gel, Pulsed-Field; Female; Hospitals; Humans; Infant; Lung; Male; Meropenem; Microbial Sensitivity Tests; Molecular Typing; Respiratory Function Tests; Thienamycins; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination; Young Adult

Cystic fibrosis is an autosomal recessive disorder characterized by chronic progressive multisystem involvement. AH1N1 virus infections caused classic influenza symptoms in the majority of cystic fibrosis patients while others experienced severe outcomes.. We report a case of late incidental cystic fibrosis diagnosis in a young Caucasian man suffering from respiratory failure following infection due to AH1N1 influenza virus. The patient was admitted to our department with fever, cough, and dyspnea at rest unresponsive to antibiotics CONCLUSIONS: Late diagnosis of cystic fibrosis in uncommon. This report highlights the importance of early cystic fibrosis diagnosis to minimize risk of occurrence of potential life-threatening complications.

Topics: Anti-Bacterial Agents; Ceftazidime; Colistin; Cystic Fibrosis; Delayed Diagnosis; Drainage, Postural; Genetic Testing; Humans; Incidental Findings; Influenza A Virus, H1N1 Subtype; Influenza, Human; Male; Meropenem; Pneumonia; Referral and Consultation; Sweat; Thienamycins; Tomography, X-Ray Computed; Young Adult

Topics: Achromobacter denitrificans; Anti-Bacterial Agents; Ceftazidime; Cephalosporins; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Humans; Meropenem; Microbial Sensitivity Tests; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Tazobactam; Thienamycins

Meropenem is frequently used to treat pulmonary exacerbations in children with cystic fibrosis (CF) in the USA. Prolonged-infusion meropenem improves the time that free drug concentrations remain above the MIC (fT> MIC) in adults, but data in CF children are sparse. We describe the population pharmacokinetics, tolerability and treatment burden of prolonged-infusion meropenem in CF children.. Thirty children aged 6-17 years with a pulmonary exacerbation received 40 mg/kg meropenem every 8 h; each dose was administered as a 3 h infusion. Pharmacokinetics were determined using population methods in Pmetrics. Monte Carlo simulation was employed to compare 0.5 with 3 h infusions to estimate the probability of pharmacodynamic target attainment (PTA) at 40% fT> MIC. NCT#01429259.. A two-compartment model fitted the data best with clearance and volume predicted by body weight. Clearance and volume of the central compartment were 0.41 ± 0.23 L/h/kg and 0.30 ± 0.17 L/kg, respectively. Half-life was 1.11 ± 0.38 h. At MICs of 1, 2 and 4 mg/L, PTAs for the 0.5 h infusion were 87.6%, 70.1% and 35.4%, respectively. The prolonged infusion increased PTAs to >99% for these MICs and achieved 82.8% at 8 mg/L. Of the 30 children, 18 (60%) completed treatment with prolonged infusion; 5 did so at home without any reported burden. Nine patients were changed to a 0.5 h infusion when discharged home.. In these CF children, meropenem clearance was greater compared with published values from non-CF children. Prolonged infusion provided an exposure benefit against pathogens with MICs ≥1 mg/L, was well tolerated and was feasible to administer in the hospital and home settings, the latter depending on perception and family schedule.

Topics: Adolescent; Anti-Bacterial Agents; Child; Cystic Fibrosis; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Infusions, Intravenous; Male; Meropenem; Microbial Sensitivity Tests; Monte Carlo Method; Prospective Studies; Thienamycins; United States

This study aimed to compare the susceptibility to carbapenems (imipenem, meropenem and doripenem) of clinical strains of Pseudomonas aeruginosa. It also studied whether susceptibility to imipenem or meropenem could predict, reliably, susceptibility to doripenem. Pseudomonal strains were collected from respiratory specimens, half of them from cystic fibrosis patients. MICs were determined according to European Committee on Antimicrobial Susceptibility Testing recommendations. Carbapenems were compared according to the susceptible, intermediate or resistant categories. A new approach also allowed comparing these carbapenems in a 'MIC score' taking into account the differences in breakpoints between drugs. One hundred thirty-nine strains were studied. They were found to be statistically more susceptible to meropenem than to the two other drugs. However, this difference was small: less than one dilution between the agents. This study also highlighted a significant correlation between susceptibility to penems taken in pairs. However, susceptibility to imipenem or meropenem did not reliably predict susceptibility to doripenem. Despite potential differences in resistance mechanisms, the Pseudomonas aeruginosa strains showed close susceptibility to three carbapenems. This was true for both cystic fibrosis patients and others. However, there were variations between strains. That justifies MICs to be determined for each of the three penems. This might be useful in case of elevated MICs and/or for potentially difficult-to-treat infections such as pneumonia in patients with cystic fibrosis patients.

Topics: Anti-Bacterial Agents; Carbapenems; Cystic Fibrosis; Doripenem; Drug Resistance, Multiple, Bacterial; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Thienamycins

A new in vitro pharmacokinetic/pharmacodynamic simulator for bacterial biofilms utilizing flow cell technology and confocal laser scanning microscopy is described. The device has the ability to simulate the changing antibiotic concentrations in humans associated with intravenous dosing on bacterial biofilms grown under continuous culture conditions. The free drug concentrations of a single 2-g meropenem intravenous bolus dose and first-order elimination utilizing a half-life of 0.895 h (elimination rate constant, 0.776 h(-1)) were simulated. The antibacterial activity of meropenem against biofilms of Pseudomonas aeruginosa PAO1 and three clinical strains isolated from patients with cystic fibrosis was investigated. Additionally, the effect of meropenem on PAO1 biofilms cultured for 24 h versus that on biofilms cultured for 72 h was examined. Using confocal laser scanning microscopy, rapid biofilm killing was observed in the first hour of the dosing interval for all biofilms. However, for PAO1 biofilms cultured for 72 h, only bacterial subpopulations at the periphery of the biofilm were affected, with subpopulations at the substratum remaining viable, even at the conclusion of the dosing interval. The described model is a novel method to investigate antimicrobial killing of bacterial biofilms using human simulated concentrations.

Topics: Administration, Intravenous; Anti-Bacterial Agents; Bacteria; Biofilms; Cystic Fibrosis; Flow Cytometry; Humans; Meropenem; Microbial Sensitivity Tests; Microscopy, Confocal; Models, Biological; Pseudomonas aeruginosa; Thienamycins

Ceftazidime is the only anti-pseudomonal beta-lactam that has been reported to be administered by extended infusion in pediatric cystic fibrosis (CF) patients. A small pediatric pharmacokinetic/pharmacodynamic study has been published regarding the use of intermittent extended infusion doripenem in the treatment of an acute pulmonary exacerbation (APE) in pediatric CF patients; however, clinical use of intermittent extended infusion doripenem in pediatric CF patients has not been previously reported. We present three cases administering intermittent extended infusion doripenem in pediatric CF patients for the treatment of an APE in the case of replacing meropenem due to shortage. The delivery of beta-lactam antibiotics via intermittent extended infusion should be considered in order to optimize the pharmacodynamics of beta-lactams in the treatment of an APE.

Topics: Adolescent; Anti-Bacterial Agents; Burkholderia cenocepacia; Burkholderia Infections; Carbapenems; Child; Cystic Fibrosis; Disease Progression; Doripenem; Drug Therapy, Combination; Female; Gram-Negative Bacterial Infections; Humans; Infusions, Intravenous; Meropenem; Pseudomonas aeruginosa; Pseudomonas Infections; Pseudomonas stutzeri; Rhodospirillaceae; Thienamycins; Tobramycin; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination

Aztreonam, cefepime, and ceftazidime are anti-pseudomonal beta-lactam antibiotics which have been previously reported to be administered by continuous infusion (CI) in pediatric CF patients. We present two cases administering intravenous (IV) meropenem and ticarcillin-clavulanate by CI in pediatric CF patients. The delivery of beta-lactam antibiotics via CI should be considered in order to optimize the pharmacodynamics (PD) of beta-lactams in the treatment of acute pulmonary exacerbations (APE).

Topics: Adolescent; Anti-Bacterial Agents; Clavulanic Acids; Cystic Fibrosis; Female; Gram-Negative Bacterial Infections; Humans; Infusions, Intravenous; Meropenem; Pneumonia, Bacterial; Pseudomonas aeruginosa; Pseudomonas Infections; Rhodospirillaceae; Thienamycins; Ticarcillin

β-Lactam antibiotics provide the cornerstone of treatment for respiratory exacerbations in patients with cystic fibrosis. Unfortunately, approximately 20% of patients develop multiple nonimmediate allergic reactions that restrict therapeutic options. The purpose of this study was to explore the chemical and immunological basis of multiple β-lactam allergy through the analysis of human serum albumin (HSA) covalent binding profiles and T-cell responses against 3 commonly prescribed drugs; piperacillin, meropenem, and aztreonam. The chemical structures of the drug haptens were defined by mass spectrometry. Peripheral blood mononuclear cells (PBMC) were isolated from 4 patients with multiple allergic reactions and cultured with piperacillin, meropenem, and aztreonam. PBMC responses were characterized using the lymphocyte transformation test and IFN-γ /IL-13 ELIspot. T-cell clones were generated from drug-stimulated T-cell lines and characterized in terms of phenotype, function, and cross-reactivity. Piperacillin, meropenem, and aztreonam formed complex and structurally distinct haptenic structures with lysine residues on HSA. Each drug modified Lys190 and at least 6 additional lysine residues in a time- and concentration-dependent manner. PBMC proliferative responses and cytokine release were detected with cells from the allergic patients, but not tolerant controls, following exposure to the drugs. 122 CD4+, CD8+, or CD4+CD8+ T-cell clones isolated from the allergic patients were found to proliferate and release cytokines following stimulation with piperacillin, meropenem, or aztreonam. Cross-reactivity with the different drugs was not observed. In conclusion, our data show that piperacillin-, meropenem-, and aztreonam-specific T-cell responses are readily detectable in allergic patients with cystic fibrosis, which indicates that multiple β-lactam allergies are instigated through priming of naïve T-cells against the different drug antigens. Characterization of complex haptenic structures on distinct HSA lysine residues provides a chemical basis for the drug-specific T-cell response.

Topics: Aztreonam; beta-Lactamase Inhibitors; beta-Lactams; Cystic Fibrosis; Drug Hypersensitivity; Haptens; Humans; Hypersensitivity; Meropenem; Molecular Structure; Piperacillin; Serum Albumin; T-Lymphocytes; Thienamycins

Expression of ampC, oprD, mexA, mexC, mexE, and mexX was studied in 25 Pseudomonas aeruginosa isolates from cystic fibrosis patients, including 14 isolates of the Liverpool epidemic strain. Overexpressed mexA or ampC and reduced oprD were associated with beta-lactam resistance. A specific combination of mexR, nalC, and nalD mutations occurred in 11 Liverpool strain isolates, including 7 with upregulated mexA.

Topics: Bacterial Outer Membrane Proteins; Bacterial Proteins; beta-Lactamases; Cystic Fibrosis; Drug Resistance, Bacterial; Drug Resistance, Multiple; Electrophoresis, Gel, Pulsed-Field; Humans; Membrane Transport Proteins; Mutation; Porins; Pseudomonas aeruginosa; Pseudomonas Infections; Reverse Transcriptase Polymerase Chain Reaction; Up-Regulation

The pathogenesis of infection with Burkholderia cepacia complex (Bcc) organisms may be linked to its capacity to invade respiratory epithelium.. An antibiotic exclusion assay was used to study B. dolosa AU4459 and B. cenocepacia J2315 invasion into wild-type (WT) and CFTR-deficient respiratory epithelial cells. Inhibitors were used to evaluate Bcc invasion dependency on host microtubule (mt) and microfilament (mf) systems.. B. dolosa entered WT-CFTR cells with 5-fold greater efficiency than CFTR deficient cells (25% vs 5%, respectively). Invasion dropped to <0.5% after either mf or mt inhibition. B. cenocepacia entered WT (0.05%) and CFTR-deficient cells (0.07%) with similarly low efficiencies, which significantly decreased with either mf or mt inhibition (0.008% and 0.002%, respectively).. B. dolosa and B. cenocepacia enter respiratory epithelial cells in a mf and mt dependent fashion. Mutated CFTR leads to less internalization of B. dolosa, but not B. cenocepacia.

Topics: Actin Cytoskeleton; Amikacin; Anti-Bacterial Agents; Burkholderia gladioli; Burkholderia Infections; Ceftazidime; Cell Line, Transformed; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Therapy, Combination; Epithelial Cells; Humans; Meropenem; Microbial Sensitivity Tests; Microscopy, Electron, Transmission; Microtubules; Respiratory Mucosa; Thienamycins; Virulence

During investigation of susceptibility testing methods for polymyxins, 24 multidrug-resistant clinical isolates of Pseudomonas aeruginosa were observed to have a distinct, reproducible phenotype in which skipped wells were observed during broth microdilution testing for polymyxin B. Possible mechanisms underlying this phenotype were investigated. The effects of various concentrations of polymyxin B on growth, the expression of resistance genes, and outer-membrane permeability were observed. Real-time PCR was performed to compare the expression, in response to selected concentrations of polymyxin B, of genes related to the PhoP-PhoQ and PmrA-PmrB two-component regulatory systems in polymyxin B-susceptible isolate PAO1, polymyxin B-resistant isolate 9BR, and two isolates (19BR and 213BR) exhibiting the skipped-well phenotype. 19BR and 213BR appeared to have similar basal levels of expression compared to that of PAO1 for phoQ, arnB, and PA4773 (from the pmrAB operon), and in contrast, 9BR had 52- and 280-fold higher expression of arnB and PA4773, respectively. The expression of arnB and PA4773 increased in response to polymyxin B in a concentration-dependent manner for 9BR but not for 19BR and 213BR. For these isolates, expression was significantly increased for arnB and PA4773, as well as phoQ, only upon exposure to 2 mug/ml polymyxin B but not at a lower concentration of 0.125 microg/ml. The sequencing of the pmrAB and phoPQ operons for all three isolates revealed a number of unique mutations compared to that for PAO1. 1-N-phenylnaphthylamine (NPN) was used to study the effect of preincubation with polymyxin B on the self-promoted uptake of polymyxin B across the outer membrane. The preincubation of cells with 2 microg/ml polymyxin B affected baseline membrane permeability in 19BR and 213BR and also resulted in a reduced rate of NPN uptake in these isolates and in PAO1 but not in 9BR. The results presented here suggest that the skipped-well isolates have the ability to adapt to specific concentrations of polymyxin B, inducing known polymyxin B resistance genes involved in generating alterations in the outer membrane.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Genotype; Microbial Sensitivity Tests; Polymyxin B; Promoter Regions, Genetic; Pseudomonas aeruginosa; Transcription Factors

The aim of cystic fibrosis (CF) care is to improve both the life expectancy and quality of life of patients. However, rising costs and limited resources of health services must be taken into account. There are many different antibiotic strategies for therapy of Pseudomonas aeruginosa infection in CF patients. In this 5-year retrospective study we found that the cost of treatment of initial infection is considerably lower than the cost of treating chronic P. aeruginosa infections. The percentage distribution of costs of antibiotic treatment in relationship to the administration route was considerably different between outpatients and inpatients. We observed an increase in antibiotic costs with the age of the patient and the decrease in FEV(1)values. The implementation of early eradication treatment, in addition to decreasing the prevalence of patients chronically infected by P. aeruginosa, might also bring about a notable decrease in costs.

Topics: Adult; Anti-Bacterial Agents; Ceftazidime; Child, Preschool; Chronic Disease; Ciprofloxacin; Clavulanic Acids; Colistin; Cost of Illness; Cystic Fibrosis; Humans; Meropenem; Pseudomonas aeruginosa; Pseudomonas Infections; Retrospective Studies; Thienamycins; Ticarcillin; Tobramycin

Topics: Adolescent; Anti-Bacterial Agents; Bacteria, Anaerobic; Bacterial Infections; Bronchopneumonia; Child; Cystic Fibrosis; Humans; Meropenem; Thienamycins

We report the case of successful treatment of a 31-year-old lady with cystic fibrosis and an en-bloc liver-pancreas transplant, who developed cepacia syndrome on a background of chronic infection with the ET12 epidemic strain of Burkholderia cenocepacia. Combination therapy with nebulised and intravenous meropenem and tobramycin led to clinical improvement with a return to baseline function and complete resolution of the acute chest X-ray changes.

Topics: Adult; Anti-Bacterial Agents; Burkholderia cepacia; Burkholderia Infections; Cystic Fibrosis; Drug Therapy, Combination; Female; Humans; Injections, Intravenous; Meropenem; Nebulizers and Vaporizers; Syndrome; Thienamycins; Tobramycin

Susceptibility (18 antimicrobial agents including high-dose tobramycin) and checkerboard synergy (23 combinations) studies were performed for 2,621 strains of Burkholderia cepacia complex isolated from 1,257 cystic fibrosis patients. Minocycline, meropenem, and ceftazidime were the most active, inhibiting 38%, 26%, and 23% of strains, respectively. Synergy was rarely noted (range, 1% to 15% of strains per antibiotic combination).

Topics: Anti-Bacterial Agents; Burkholderia cepacia complex; Burkholderia Infections; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Drug Synergism; Humans; Microbial Sensitivity Tests

The determination of synergistic effects of antimicrobial drug combinations can lead to improved therapeutic options in the antibiotic treatment of cystic fibrosis patients who are chronically infected with multiresistant Pseudomonas aeruginosa isolates. The aim of this study was to evaluate the performance of the E test versus the standard agar dilution checkerboard susceptibility test in the assessment of synergy and, in addition, to determine the activity of two antimicrobial combinations against 163 multiresistant P. aeruginosa isolates from cystic fibrosis patients. The agreement between the checkerboard method and the E test was excellent (>90%) for nonmucoid as well as mucoid isolates from cystic fibrosis patients. The rate of synergy was higher for the antibiotic combination of ceftazidime and tobramycin (28.8% of the cystic fibrosis strains) than for the combination of meropenem and tobramycin (19.0%). However, the probability of synergy for the second antibiotic combination increased significantly when the synergy of the first antibiotic combination had already been demonstrated (Fischer's exact test, p=0.049). The results show that the E test is a valuable and practical method for routine microbiological diagnostics and can aid in the selection of improved antibiotic options in the treatment of cystic fibrosis patients chronically infected with P. aeruginosa.

Topics: Anti-Bacterial Agents; Ceftazidime; Cystic Fibrosis; Drug Resistance, Multiple; Drug Synergism; Drug Therapy, Combination; Humans; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Reproducibility of Results; Thienamycins; Tobramycin

A 31-year-old man with cystic fibrosis was diagnosed with multidrug-resistant Burkholderia cepacia pneumonia. Meropenem 2000 mg every 8 hours was administered as a 3-hour infusion to maximize pharmacodynamic exposure; oral minocycline 100 mg twice/day was also given. Blood samples were collected to confirm meropenem concentrations. Concentrations above the mimimum inhibitory concentration (MIC) of 8 microg/ml were achieved for 52% of the dosing interval, which is greater than what is required for a bactericidal effect. The patient's condition improved, he was discharged, and completed a 3-week course of the antibiotic regimen. After 6 months, he had remained at his baseline level of health. This case demonstrates that pharmacodynamic principles can be used to design an antibiotic dosing regimen that can achieve optimal exposures when the MIC is above that considered susceptible to conventional dosing strategies.

Topics: Adult; Burkholderia cepacia; Burkholderia Infections; Cystic Fibrosis; Drug Administration Schedule; Drug Resistance, Multiple, Bacterial; Humans; Infusions, Intravenous; Male; Meropenem; Pneumonia, Bacterial; Thienamycins

To report a case of successful meropenem desensitization in a patient with cystic fibrosis (CF) with documented hypersensitivity to multiple antibiotics including carbapenems.. A 20-year-old white man with CF was admitted to the hospital for treatment of an acute pulmonary exacerbation caused by multidrug-resistant Burkholderia cepacia complex and methicillin-resistant Staphylococcus aureus (MRSA). Past treatments of his CF exacerbations were complicated by urticarial eruptions following administration of beta-lactams, including meropenem, and ototoxicity from aminoglycosides. Skin testing revealed hypersensitivity reactions to beta-lactam antibiotics including penicillin, piperacillin/tazobactam, ceftazidime, and imipenem. A literature review (MEDLINE, January 3, 2002) and communication with the manufacturer of meropenem revealed no specific information on desensitizing patients to this agent. Because of meropenem's activity against B. cepacia complex alone and in combination with other antimicrobials, a desensitization protocol was adapted and applied to meropenem in an effort to provide the most beneficial treatment available. A 12-dose escalation protocol was successfully employed without incident.. Antimicrobial therapy is limited in CF patients by susceptibility profiles of common infecting organisms (e.g., Pseudomonas spp., B. cepacia complex, MRSA). Unfortunately, host responses may further reduce the utility of many effective antibiotic classes due to hypersensitivity and/or adverse reactions. Desensitization is a useful alternative that allows the administration of beneficial medications to patients with documented allergy histories.. Meropenem is an important treatment option in the CF population, particularly due to its activity against B. cepacia complex. Successful desensitization using a dose-escalation protocol in patients with a documented carbapenem allergy will allow the most beneficial therapy to continue.

Topics: Adult; Burkholderia cepacia; Cystic Fibrosis; Desensitization, Immunologic; Drug Hypersensitivity; Exocrine Pancreatic Insufficiency; Humans; Immunoglobulin E; Infusion Pumps; Injections; Injections, Intravenous; Male; Meropenem; Nasal Polyps; Skin Tests; Staphylococcus aureus; Thienamycins; Treatment Outcome

The objective of the present study was to evaluate the activity of meropenem (a beta-lactam carbapenem with good bactericidal potency and a very wide spectrum of activity) and of ticarcillin, ceftazidime ciprofloxacin, tobramycin, cefepime, which are the most commonly used antimicrobial agents for treatment of pulmonary infections associated with CF. The effect of these antibiotics was tested on 27 multiresistant strains isolated from 24 CF patients during 2000 and 2001. Furthermore, the in vitro synergistic effect of meropenem in association with the other antibiotics was evaluated. Ciprofloxacin, ticarcillin, meropenem and ceftazidime had the most activity and inhibited 66%, 37%, 36% and 33% of strains respectively. The addition of a second antibiotic to meropenem resulted in a synergistic effect on 5 (18.5%) isolates; on average 2.8 synergistic combinations where determined per strain. Of these 27 isolates, antagonism was observed in 3 (11%) strains (1 antagonistic combination per strain). Our study suggests that selecting effective double antibiotic therapy cannot be made empirically for CF patients infected with Gram-negative multiresistant bacilli. Therefore in vitro methods for testing double antibiotic combinations are mandatory.

Topics: Anti-Bacterial Agents; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Drug Synergism; Drug Therapy, Combination; Female; Gram-Negative Bacteria; Humans; Male; Meropenem; Microbial Sensitivity Tests; Sampling Studies; Sensitivity and Specificity; Thienamycins

Resistance patterns that are currently problematic in Europe can vary greatly within the same species over time, among various patient populations and among geographic regions on the same continent. The results from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program, which monitors carbapenem resistance rates in institutions using meropenem, were used to determine resistance differences among Proteus mirabilis. MIC results from 688 P. mirabilis strains were classified into 4 patient care groups: ICU (n=426), neutropenia patients (NP; n=145), general wards (n=97) and cystic fibrosis patients (CF; n=20). A total of 40 centers from 12 European countries have participated since 1997, divided into 3 geographic regions (East, North, South). All testing was performed by NCCLS reference methods and interpretive criteria, including screening of extended-spectrum beta-lactamase (ESBL) phenotypes. Over the monitored interval the resistance rates varied for each agent without a clear trend toward a greater rate. Rank order of susceptibility was: meropenem (99%) > piperacillin/tazobactam (TAZ; 96%) > cefepime (95%) > ceftazidime (CAZ; 94%) > imipenem (IPM; 92%). Ciprofloxacin (CIP) was the least active agent tested (MIC90 4 microg/ml; 86% susceptible). Unexpectedly, 3.6% of P. mirabilis were imipenem-resistant (MIC, > or = 16 microg/ml). Greater rates of resistance were found for strains from NP and CF patients, and from eastern or southern European sites, usually associated with epidemic clusters. Generally susceptible species such as P. mirabilis have recently emerged as therapeutic problems in European medical centers following mutations that compromise CIP, CAZ and aminoglycoside use. Imipenem also showed decreased susceptibility of greater than 7% compared to less than 1% for meropenem. Continued surveillance by the MYSTIC Program appears to be a prudent practice to focus effective empiric treatment regimens.

Topics: Anti-Bacterial Agents; Cefepime; Ceftazidime; Cephalosporins; Ciprofloxacin; Critical Care; Cystic Fibrosis; Data Collection; Drug Resistance, Bacterial; Europe; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Neutropenia; Penicillanic Acid; Piperacillin; Population Surveillance; Proteus Infections; Proteus mirabilis; Tazobactam; Thienamycins

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program is a longitudinal global antimicrobial surveillance study that compares the activity of meropenem and comparator antimicrobial agents against pathogens isolated from intensive care, neutropenic or cystic fibrosis patients, and general wards. Data from the different European MYSTIC Program units (1997-2000) showed that the most prevalent isolates tested overall were methicillin-susceptible Staphylococcus aureus (MSSA; in accordance with study design methicillin-resistant S. aureus was not tested), Pseudomonas aeruginosa and Escherichia coli. In all the unit types, E. coli (approximately 20% having an extended spectrum beta-lactamase phenotype) and MSSA were highly susceptible to meropenem (97-99% susceptibility). Isolates of MSSA showed lower levels of susceptibility to ciprofloxacin (61-77% susceptibility) in both cystic fibrosis and neutropenia patients, and particularly high levels of resistance to ceftazidime (38% susceptibility) in cystic fibrosis units. Ciprofloxacin (54% susceptibility) and gentamicin (46% susceptibility) demonstrated low levels of activity against P. aeruginosa (frequently encountered in cystic fibrosis units). Meropenem and piperacillin/tazobactam were the most active agents against P. aeruginosa in all the unit types. Carbapenems and piperacillin/tazobactam have sustained > 90% susceptibility rates overall against the most frequently isolated pathogens. The analysis of specific units that house patients with a high-risk of contracting antimicrobial-resistant pathogens remains very important for the optimal selection of empiric regimens.

Topics: Burkholderia cepacia; Cystic Fibrosis; Databases, Factual; Escherichia coli; Europe; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Intensive Care Units; Meropenem; Neutropenia; Patients' Rooms; Pseudomonas aeruginosa; Thienamycins

We studied 67 Pseudomonas aeruginosa isolates from cystic fibrosis patients, and compared their in vitro susceptibility to two carbapenems (meropenem and imipenem) and two cephalosporins (cefepime and ceftazidime). The carbapenems were more effective in vitro than the cephalosporins: 92.5% of isolates were susceptible to the former and 77.6% to the latter. Essentially no difference was found between meropenem and imipenem. More discrepancies were seen between cefepime and ceftazidime: four of 67 isolates (6.0%) were more susceptible to cefepime than to ceftazidime, while eight (11. 9%) were more susceptible to ceftazidime than to cefepime.

Topics: Carbapenems; Cefepime; Ceftazidime; Cephalosporins; Cystic Fibrosis; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Thienamycins

We evaluated the activities of meropenem, imipenem, temocillin, piperacillin, and ceftazidime by determination of the MICs for 66 genotypically characterized Burkholderia cepacia isolates obtained from the sputum of cystic fibrosis patients. In vitro synergy assays, as performed by the time-kill methodology, of two- and three-drug combinations of the beta-lactams with tobramycin, rifampin, and/or ciprofloxacin were also performed with 10 strains susceptible, intermediate, or resistant to fluoroquinolones. On the basis of the MICs, meropenem and temocillin were the most active beta-lactam agents, with MICs at which 90% of isolates are inhibited of 8 and 32 micrograms/ml, respectively. The addition of ciprofloxacin significantly enhanced the killing activities of piperacillin, imipenem, and meropenem against the 10 strains tested (P < 0.05). The best killing activity was obtained with the combination of meropenem and ciprofloxacin, with bactericidal activity of 3.31 +/- 0.36 log10 CFU/ml (P < 0.05). Compared to the activity of the two-drug beta-lactam-ciprofloxacin combination, the addition of rifampin or tobramycin did not significantly increase the killing activity (P > 0.05). The three-drug combinations (with or without ciprofloxacin) significantly enhanced the killing activities of piperacillin, imipenem, and meropenem relative to the activities of the beta-lactams used alone (P < 0.05). The combination beta-lactam-ciprofloxacin-tobramycin was the combination with the most consistently synergistic effect.

Topics: Burkholderia cepacia; Burkholderia Infections; Ceftazidime; Ciprofloxacin; Cystic Fibrosis; Drug Synergism; Drug Therapy, Combination; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Penicillins; Piperacillin; Rifampin; Thienamycins; Tobramycin

The pharmacokinetics of meropenem were studied after single i.v. infusions of 15 mg meropenem/kg body weight in eight subjects with cystic fibrosis (CF) and eight healthy volunteers matched for age, sex, and weight. Significantly shorter terminal half-lives (mean, 0.74 h vs. 0.99 h) and mean residence times (mean, 1.09 h vs. 1.39 h) were noted in CF subjects. Plasma and renal clearances tended to be higher and distribution volumes smaller among the patients, but differences were not statistically significant. The results are consistent with the findings for many other beta-lactam agents used in CF patients. Assuming a MIC90 of 4 mg/l for meropenem against Pseudomonas aeruginosa, the time above the MIC was less than 3.3 h in six of the eight CF patients. This finding should be kept in mind when designing treatment regimens with meropenem in CF subjects.

Topics: Adult; Area Under Curve; Cystic Fibrosis; Female; Humans; Male; Meropenem; Pseudomonas aeruginosa; Pseudomonas Infections; Thienamycins