rifampin and Pneumonia--Bacterial

Pneumonia caused by Rhodococcus equi remains an important cause of disease and death in foals. The combination of a macrolide (erythromycin, azithromycin, or clarithromycin) with rifampin remains the recommended therapy for foals with clinical signs of infection caused by R equi. Most foals with small, subclinical ultrasonographic pulmonary lesions associated with R equi recover without therapy, and administration of antimicrobial agents to these subclinically affected foals does not hasten lesion resolution relative to administration of a placebo. Resistance to macrolides and rifampin in isolates of R equi is increasing.

Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Azithromycin; Clarithromycin; Drug Resistance, Multiple, Bacterial; Erythromycin; Horse Diseases; Horses; Pneumonia, Bacterial; Rhodococcus equi; Rifampin

Infection with Rhodococcus equi is an important cause of pneumonia in foals, but other organ systems may also be affected. The intracellular presence of R. equi and the formation of granulomatous and suppurative inflammatory tissue mean that prolonged treatment is needed. The pharmacological properties of the combination of erythromycin and rifampicin have improved the survival of foals infected with R. equi; however, erythromycin can cause adverse reactions in foals and mares, which has prompted the search for alternative therapies. The combination of azithromycin or clarithromycin with rifampicin seems to be a promising alternative. However these combinations are expensive and adverse effects remain to be determined, especially in the dams of treated foals. Thus correct diagnosis and appropriate use of drugs are essential for the treatment of R. equi infection in foals.

Topics: Actinomycetales Infections; Animals; Animals, Newborn; Anti-Bacterial Agents; Azithromycin; Clarithromycin; Drug Therapy, Combination; Erythromycin; Horse Diseases; Horses; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Treatment Outcome

Topics: Clarithromycin; Diagnosis, Differential; Drug Therapy, Combination; Ethambutol; Humans; Isoniazid; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Mycobacterium Infections, Nontuberculous; Mycobacterium kansasii; Pneumonia, Bacterial; Prognosis; Rifampin; Streptomycin

Chryseobacterium meningosepticum is a ubiquitous Gram-negative bacillus historically associated with meningitis in premature neonates. We report 15 positive cultures and 6 cases of infection among immunocompromised adults at our institution over a 10-year period and review the English-language literature on C. meningosepticum. Excluding the present series, there are 308 reports of positive cultures in the literature, of which 59% were determined to represent true infections. Sixty-five percent of those infected were younger than 3 months of age. Meningitis was the most common infectious syndrome among neonates, seen in 84% of cases and associated with a 57% mortality rate. Less commonly reported infections among infants included sepsis (13%) and pneumonia (3%). Pneumonia was the most frequent infection among the postneonatal group, accounting for 40% of cases, followed by sepsis (24%), meningitis (18%), endocarditis (3%), cellulitis (3%), abdominal infections (3%), eye infections (3%), and single case reports of sinusitis, bronchitis, and epididymitis. The 6 cases in our series were all adults, with a mean age of 58.7 years. Sites of C. meningosepticum infection were limited to the lungs, bloodstream, and biliary tree. Infection in our series was associated with prolonged hospitalization, prior exposure to multiple antibiotics, and host immunocompromise, particularly neutropenia. C. meningosepticum is resistant to multiple antibiotics, and disk dilution is notoriously unreliable for antibiotic sensitivity testing. Sensitivity testing on the 15 isolates from our institution revealed the most efficacious antibiotics to be minocycline (100% sensitive), rifampin (93%), trimethoprim-sulfamethoxazole (67%), and ciprofloxacin (53%). In contrast to reports in the literature, the isolates in our series displayed widespread resistance to vancomycin (100% resistant or intermediately sensitive), erythromycin (100%), and clindamycin (86%). These findings have important implications for the clinician when choosing empiric antibiotic regimens for patients with risk factors for C. meningosepticum infection.

Topics: Adult; Aged; Anti-Bacterial Agents; Antibiotics, Antitubercular; Breast Neoplasms; Ciprofloxacin; Drug Resistance, Microbial; Female; Flavobacterium; Gram-Negative Bacterial Infections; Humans; Immunocompromised Host; Infant; Infant, Newborn; Leukemia, Myeloid, Acute; Liver Transplantation; Male; Meningitis, Bacterial; Middle Aged; Minocycline; Pneumonia, Bacterial; Rifampin; Sepsis; Trimethoprim, Sulfamethoxazole Drug Combination

The objectives of the present study were to determine the relative efficacy of tulathromycin, azithromycin, or azithromycin with rifampin for the treatment of pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi. Foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-15 cm; n=120) were randomly allocated in four equal treatment groups: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy, orally; (3) azithromycin with rifampin, orally; (4) saline intramuscularly as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study. The proportion of foals that recovered without the need for a change in therapy was significantly higher for foals treated with azithromycin (29 of 30) or azithromycin with rifampin (28 of 30) than for foals treated with a placebo (20 of 30). Additionally, azithromycin or azithromycin with rifampin resulted in a significantly faster decrease in the number of abscesses and abscess score compared with a placebo. The proportion of foals treated with tulathromycin that recovered (27 of 30) was not significantly different from that of foals treated with a placebo. Azithromycin alone or in combination with rifampin was beneficial in the study population.

Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Azithromycin; Disaccharides; Double-Blind Method; Drug Therapy, Combination; Endemic Diseases; Germany; Heterocyclic Compounds; Horse Diseases; Horses; Lung Abscess; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Severity of Illness Index; Treatment Outcome

Rhodococcus equi is a soil borne bacterium that causes severe morbidity and death in young foals. The economic costs of the disease include loss of life, treatment expenses, veterinary monitoring expenses and, perhaps most importantly, potential reduction in future athletic performance in horses that suffer severe lung abscessations caused by R. equi. Current standard of care for pneumonia caused by R. equi is treatment with a macrolide antimicrobial and rifampicin. However, the hallmark of pneumonia caused by R. equi is severe formation of pyogranulomas and a walling off effect that can prevent systemic antibiotics from reaching antimicrobial concentrations in lung tissues. It is hypothesized that streptolysin O (SLO) used as an adjunct therapy with antibiotics will reduce the duration and severity of disease caused by R. equi pneumonia compared to antibiotic therapy alone. Addition of SLO to the antibiotic enhanced clinical responses compared to the other groups, including the antibiotic alone group. Of particular significance were lower bacterial counts in the lungs and longer survival time in those foals treated with SLO and antibiotics.

Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Bacterial Proteins; Fibrinogen; Horse Diseases; Horses; Lung; Macrolides; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Streptolysins

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Antineoplastic Agents; Cell Line; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Molecular Structure; Pneumonia, Bacterial; Pore Forming Cytotoxic Proteins; Structure-Activity Relationship; Wasp Venoms

Anti-interferon-gamma (IFN-γ) autoantibodies has been recognised as an adult-onset immunodeficiency in the past decade in people who originate from Southeast Asia. These patients are susceptible to particular opportunistic infections, especially non-tuberculous mycobacteria (NTM). We present the case of a woman whom originally came from Thailand with disseminated

Topics: Adult; Anti-Bacterial Agents; Asian People; Autoantibodies; Azithromycin; Bacteremia; Disease Progression; Ethambutol; Female; Humans; Immunologic Deficiency Syndromes; Immunologic Factors; Interferon-gamma; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Pericarditis; Pleurisy; Pneumonia, Bacterial; Recurrence; Rifampin; Rituximab; Thailand

The practice of prophylactic administration of a macrolide antimicrobial with rifampin (MaR) to apparently healthy foals with pulmonary lesions identified by thoracic ultrasonography (i.e., subclinically pneumonic foals) is common in the United States. The practice has been associated epidemiologically with emergence of R. equi resistant to MaR. Here, we report direct evidence of multi-drug resistance among foals treated with MaR. In silico and in vitro analysis of the fecal microbiome and resistome of 38 subclinically pneumonic foals treated with either MaR (n = 19) or gallium maltolate (GaM; n = 19) and 19 untreated controls was performed. Treatment with MaR, but not GaM, significantly decreased fecal microbiota abundance and diversity, and expanded the abundance and diversity of antimicrobial resistance genes in feces. Soil plots experimentally infected with Rhodococcus equi (R. equi) and treated with MaR selected for MaR-resistant R. equi, whereas MaR-susceptible R. equi out-competed resistant isolates in GaM-treated or untreated plots. Our results indicate that MaR use promotes multi-drug resistance in R. equi and commensals that are shed into their environment where they can persist and potentially infect or colonize horses and other animals.

Topics: Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Drug Resistance, Multiple; Feces; Horse Diseases; Horses; Macrolides; Microbial Sensitivity Tests; Organometallic Compounds; Pneumonia, Bacterial; Pyrones; Rhodococcus equi; Rifampin

Whether two-drug therapy (clarithromycin and ethambutol) for Mycobacterium avium complex (MAC) pulmonary disease contributes to the development of macrolide-resistant MAC is unclear.. To compare the incidence of macrolide-resistant MAC between patients treated with two-drug therapy (clarithromycin and ethambutol) and the standard three-drug therapy (clarithromycin, ethambutol, and rifampicin) for MAC pulmonary disease.. We retrospectively reviewed 147 patients with treatment-naive MAC pulmonary disease who had received two-drug therapy (n = 47) or three-drug therapy (n = 100) between 1997 and 2016 at National Hospital Organization, Tenryu Hospital, Hamamatsu, Japan. The risk of development of macrolide-resistant MAC was evaluated by calculating the cumulative incidence rate using Gray's test.. The median follow-up period was 74.5 months. During the follow-up period, one of the 47 patients (2.1%) in the two-drug group developed macrolide-resistant MAC, compared to 12 of the 100 patients (12.0%) in the three-drug group. The cumulative incidence rate of macrolide-resistant MAC was lower in the two-drug group than in the three-drug group (0.0023; 95% confidence interval, 0.002 to 0.107 versus 0.200; 95% confidence interval, 0.100 to 0.324, p = 0.0593).. These results suggest that two-drug treatment with clarithromycin and ethambutol for MAC pulmonary disease does not lead to a higher incidence of resistance acquisition to clarithromycin than the standard three-drug treatment.

Topics: Aged; Anti-Bacterial Agents; Clarithromycin; Drug Resistance, Bacterial; Drug Therapy, Combination; Ethambutol; Female; Humans; Incidence; Japan; Macrolides; Male; Middle Aged; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Negative Results; Pneumonia, Bacterial; Rifampin

Rhodococcus equi causes severe pneumonia in foals and is most often recognized in people as an opportunistic pathogen. Longitudinal studies examining antimicrobial-resistant R. equi from environmental samples are lacking. We hypothesized that antimicrobial-resistant R. equi would be detectable in the ground (pasture soil or stall bedding) and air at breeding farms with previous documentation of foals infected with resistant isolates, and that concentrations of resistant isolates would increase over time during the foaling season. In this prospective cohort study, ground and air samples were collected from stalls and paddocks in January, March, May and July of 2018 at 10 horse-breeding farms with history of foal pneumonia attributed to macrolide- or Rifampicin-resistant R. equi. Environmental samples were cultured in the presence and absence of macrolides and Rifampicin to select for resistant organisms. Data were analyzed with linear mixed-effects and Hurdle models. Concentrations of total R. equi in bedding or air of stalls were significantly (P < 0.05) higher in January than other months. The proportion of resistant R. equi in soil samples from paddocks was significantly (P < 0.05) higher than stall bedding during all months. For each month, air samples from paddocks had a significantly (P < 0.05) higher proportion of resistant isolates than those from stalls. Fifty-five percent of resistant soil isolates and 34% of resistant air isolates were considered virulent by identification of the vapA gene. Concentrations of resistant R. equi isolates did not increase over time during the foaling season. Antimicrobial-resistant R. equi can persist in the environment at farms with a history of pneumonia caused by resistant R. equi infections, and exposure to resistant isolates in paddocks and stalls appears stable during the foaling season. Resistant isolates in the environment not only pose a risk for disease but also can serve as a repository for dissemination of resistance genes.

Topics: Actinomycetales Infections; Air Microbiology; Animal Husbandry; Animals; Breeding; Drug Resistance, Multiple, Bacterial; Farms; Horse Diseases; Horses; Housing, Animal; Kentucky; Macrolides; Pneumonia, Bacterial; Prospective Studies; Rhodococcus equi; Rifampin; Seasons; Soil Microbiology; Virulence

The chloramphenicol/florfenicol resistance gene cfr, which mediates cross-resistance to linezolid and other classes of antimicrobial agents, represents a global therapeutic challenge due to its dissemination among MDR nosocomial pathogens, including MRSA. This study aimed to compare the efficacy of the linezolid/rifampicin combination in a murine pneumonia model caused by cfr-positive and cfr-negative clinical MRSA strains.. Synergistic activity between linezolid and rifampicin was evaluated by chequerboard and time-kill assays. Pharmacokinetic profiles in plasma and epithelial lining fluid (ELF) as well as the therapeutic efficacy of linezolid alone and in combination with rifampicin were investigated in a murine pneumonia model. The Emax Hill equation was used to model the dose-response relationship.. Increased susceptibility of the study MRSA strains to linezolid was observed with the rifampicin combination (MIC decreased 2- to 16-fold versus linezolid alone). The combination had synergistic activity (fractional inhibitory concentration index ≤0.5) against all cfr-positive MRSA isolates. Linezolid demonstrated excellent pulmonary penetration with an ELF/fplasma AUC ratio of 2.68 ± 0.17. The addition of rifampicin significantly improved the efficacy of linezolid in the pneumonia model due to cfr-positive and cfr-negative MRSA strains. The fAUC/MIC targets of linezolid associated with stasis, 1 log10 kill and 2 log10 kill were 15.9, 38.8 and 175 in plasma, and 43.5, 108 and 415 in ELF, respectively. Importantly, the linezolid fAUC/MIC targets in both plasma and ELF were 2.4-6.7 times lower in combined linezolid/rifampicin therapy versus linezolid monotherapy (P < 0.005).. Combination of linezolid with rifampicin significantly improved the efficacy of linezolid in the murine pneumonia model caused by MRSA strains in the presence and absence of the cfr gene.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Female; Linezolid; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin; Specific Pathogen-Free Organisms; Staphylococcal Infections

Emerging resistance to colistin in clinical Acinetobacter baumannii isolates is of growing concern. Since current treatment options for these strains are extremely limited, we investigated the in vitro activities of various antimicrobial combinations against colistin-resistant A. baumannii Nine clinical isolates (8 from bacteremia cases and 1 from a pneumonia case) of colistin-resistant A. baumannii were collected in Asan Medical Center, Seoul, South Korea, between January 2010 and December 2012. To screen for potential synergistic effects, multiple combinations of two antimicrobials among 12 commercially available agents were tested using the multiple-combination bactericidal test (MCBT). Checkerboard tests were performed to validate these results. Among the 9 colistin-resistant strains, 6 were pandrug resistant and 3 were extensively drug resistant. With MCBT, the most effective combinations were colistin-rifampin and colistin-teicoplanin; both combinations showed synergistic effect against 8 of 9 strains. Colistin-aztreonam, colistin-meropenem, and colistin-vancomycin combinations showed synergy against seven strains. Colistin was the most common constituent of antimicrobial combinations that were active against colistin-resistant A. baumannii Checkerboard tests were then conducted in colistin-based combinations. Notably, colistin-rifampin showed synergism against all nine strains (100%). Both colistin-vancomycin and colistin-teicoplanin showed either synergy or partial synergy. Colistin combined with another β-lactam agent (aztreonam, ceftazidime, or meropenem) showed a relatively moderate effect. Colistin combined with ampicillin-sulbactam, tigecycline, amikacin, azithromycin, or trimethoprim-sulfamethoxazole demonstrated limited synergism. Using MCBT and checkerboard tests, we found that only colistin-based combinations, particularly those with rifampin, glycopeptides, or β-lactams, may confer therapeutic benefits against colistin-resistant A. baumannii.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Anti-Bacterial Agents; Aztreonam; Bacteremia; Ceftazidime; Colistin; Drug Combinations; Drug Resistance, Multiple, Bacterial; Drug Synergism; Humans; Meropenem; Microbial Sensitivity Tests; Pneumonia, Bacterial; Retrospective Studies; Rifampin; Teicoplanin; Thienamycins; Vancomycin

Existing literature is inconclusive regarding how the nodular bronchiectatic form of Mycobacterium avium complex (MAC) disease will progress without treatment and when treatment initiation should be considered.. To assess the natural course of MAC pulmonary disease by serial thin-section computed tomography (CT).. Of 339 patients with nodular bronchiectatic form of MAC disease, we selected 265 untreated patients who had serial CTs (mean observation period, 32 ± 21 mo). Two independent chest radiologists reviewed retrospectively all CT scans for the presence and extent of lung abnormalities (maximal total score, 30).. Of 265 patients, 126 patients (48%) had disease that had progressed and that needed treatment owing to radiologic deterioration or worsening symptoms, and the remaining 139 patients (52%) did not. On multivariate analysis, the presence of cavity (adjusted hazard ratio, 2.06; P = 0.004) and consolidation (adjusted hazard ratio, 1.55; P = 0.019) at initial CT remained as independent factors associated with disease progression and treatment requirement. The presence of cavitary lesions demonstrated the highest positive predictive value (61%) and significant correlation (P = 0.005) with smear positivity. Differences in the extent of each pattern and total CT score in the serial studies were significantly larger (P < 0.05) in patients requiring treatment. The total CT score increased by 2.41 in the treatment-requiring group compared with 0.25 in the group that did not receive treatment.. Without treatment, about half of patients demonstrate progressive disease on serial CT over a mean follow-up period of 32 months and, thus, required treatment. Patients showing cavities or consolidation on initial CT are more likely to have progressive disease and thus to require treatment eventually.

Topics: Aged; Anti-Bacterial Agents; Azithromycin; Bronchiectasis; Clarithromycin; Disease Progression; Drug Therapy, Combination; Ethambutol; Female; Humans; Lung; Male; Middle Aged; Multiple Pulmonary Nodules; Multivariate Analysis; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Pneumonia, Bacterial; Proportional Hazards Models; Retrospective Studies; Rifampin; Tomography, X-Ray Computed

Macrolide and rifampin resistance developed on a horse breeding farm after widespread use was instituted for treatment of subclinical pulmonary lesions in foals. Resistance occurred in 6 (24%) of 25 pretreatment and 8 (62%) of 13 (62%) posttreatment isolates from affected foals. Drug-resistant isolates formed 2 distinct genotypic clusters.

Topics: Actinomycetales Infections; Animals; Asymptomatic Infections; Breeding; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Horse Diseases; Horses; Kentucky; Macrolides; Molecular Typing; Phylogeny; Pneumonia, Bacterial; Repetitive Sequences, Nucleic Acid; Rhodococcus equi; Rifampin; Ultrasonography

Topics: Agglutination Tests; Animal Husbandry; Animals; Brucella; Brucellosis; Dairy Products; Doxycycline; Food Contamination; Humans; Male; Milk; Occupational Diseases; Pleural Effusion; Pneumonia, Bacterial; Rifampin; Sheep; Spain; Tomography, X-Ray Computed; Young Adult

Currently recommended multidrug treatment regimens for Mycobacterium avium complex (MAC) lung disease yield limited cure rates. This results, in part, from incomplete understanding of the pharmacokinetics and pharmacodynamics of the drugs.. To study pharmacokinetics, pharmacodynamics, and drug interactions of multidrug treatment regimens in a large cohort of patients with MAC lung disease.. We retrospectively collected pharmacokinetic data of all patients treated for MAC lung disease in the Adult Care Unit at National Jewish Health, Denver, Colorado, in the January 2006 to January 2010 period; we retrospectively calculated areas under the time-concentration curve (AUC). Minimum inhibitory concentrations (MIC) of their MAC isolates were retrieved for pharmacodynamic calculations.. We included 531 pharmacokinetic analyses, performed for 481 patients (84% females; mean age, 63 yr; mean body mass index, 21.6). Peak serum concentrations (C(max)) below target range were frequent for ethambutol (48% of patients); clarithromycin (56%); and azithromycin (35%). Concurrent administration of rifampicin led to 68%, 23%, and 10% decreases in C(max) of clarithromycin, azithromycin, and moxifloxacin. C(max)/MIC or AUC/MIC ratios associated with bactericidal activity were seldom met; 57% of patients achieved target ratios for ethambutol, versus 42% for clarithromycin, 19% for amikacin, 18% for rifampicin, and 11% for moxifloxacin.. Currently recommended regimens for MAC lung disease yield important pharmacologic interactions and low concentrations of key drugs including macrolides. Pharmacodynamic indices for rifampicin, clarithromycin, amikacin, and moxifloxacin are seldom met. This may partly explain the poor outcomes of currently recommended treatment regimens. Trials of new drugs and new dosing strategies are needed.

Topics: Adult; Aged; Amikacin; Antibiotics, Antitubercular; Area Under Curve; Clarithromycin; Cohort Studies; Colorado; Drug Interactions; Drug Resistance, Bacterial; Drug Therapy, Combination; Ethambutol; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Pneumonia, Bacterial; Retrospective Studies; Rifabutin; Rifampin

The incidence of carbapenem-resistant Acinetobacter baumannii infection is increasing, which might be associated with high morbidity and mortality among critically ill patients with limited therapeutic options. This study was conducted to evaluate the clinical and microbiological features of carbapenem-resistant A. baumannii bacteraemia. The medical records of 28 adult patients with this bacteraemia admitted to Korea University Guro Hospital, from January 2005 through December 2010, were reviewed. Using the 28 bloodstream isolates, we intended to detect genes encoding carbapenemases, and investigate the inoculum effect on each of the antimicrobial agents rifampicin, imipenem, colistin and tigecycline. With one blood isolate from a patient with pneumonia, rifampicin-inducible resistance was examined using the experimental mouse pneumonia model. Out of 28 carbapenem-resistant A. baumannii bloodstream infections (BIs), the most common primary focus was the central venous catheter (35.7 %) and then the lung (32.1 %). The 30 day overall mortality was 53.6 %; in most cases (80 %) the patients died within 10 days after the onset of the bacteraemia. By univariate analysis, inappropriate antimicrobial therapy (73.3 vs 30.8 %, P = 0.02), mechanical ventilation (53.3 vs 15.4 %, P = 0.04) and a high Pitt bacteraemia score (4.9±1.9 vs 2.2±1.2, P<0.01) were statistically significant risk factors for mortality, while only a high Pitt bacteraemia score (odds ratio 2.6; 95 % confidence interval 1.1-6.5) was independently associated with 30 day mortality by multivariate analysis. All 28 isolates had the bla(OXA-51)-like gene with upstream ISAbaI, 2 of which additionally had the bla(OXA-58)-like gene and the bla(OXA-23)-like gene. Inoculum effect and rifampicin inducible resistance were not detected. Considering the rapid progression to death in carbapenem-resistant A. baumannii BIs, early empirical antibiotic therapy would be warranted based on the local microbiological data in each hospital.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Adult; Aged; Animals; Bacteremia; beta-Lactam Resistance; beta-Lactamases; Carbapenems; Disease Models, Animal; Female; Genes, Bacterial; Humans; Male; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Middle Aged; Pneumonia, Bacterial; Republic of Korea; Rifampin; Risk Factors

The objective of this work was to evaluate the efficacy of rifampin, and its combinations with imipenem or sulbactam, in an experimental pneumonia model caused by two panresistant Acinetobacter baumannii strains (HUVR99 and HUVR113). Minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) (μg/ml) of the strains were rifampin 128/>128 for both strains, imipenem 128/>256 and 256/>256 for HUVR99 and HUVR113, respectively, and sulbactam >256/>256 for both strains. In time-kill studies, at MICs, rifampin was bactericidal for both strains and sulbactam against the HUVR99 strain. Rifampin plus imipenem or sulbactam, at the MIC or mice C (max), were synergistic. In vivo, against HUVR99 and HUVR113, rifampin (73% and 40%) and its combinations improved the survival with respect to the control group (20% and 0%, p < 0.05), respectively. Rifampin (87% and 46%) and its combinations improved the sterilization of blood cultures with respect to the control groups (0%, p < 0.05). In regard to the bacterial clearance from lungs, rifampin (2.57 ± 2.47 and 5.35 ± 3.03 log(10) cfu/g) and its combinations with imipenem or sulbactam diminished the bacterial lung concentration with respect to the control group (10.89 ± 3.00 and 11.86 ± 0.49, p < 0.05) with both strains. In conclusion, rifampin alone or associated to imipenem or sulbactam were effective for the treatment of murine pneumonia caused by selected panresistant A. baumannii strains.

Topics: Acinetobacter baumannii; Animals; Anti-Bacterial Agents; Bacterial Load; Disease Models, Animal; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Imipenem; Lung; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Microbial Viability; Pneumonia, Bacterial; Rifampin; Rodent Diseases; Sulbactam; Treatment Outcome

Paragonimiasis is a food-borne zoonosis caused by a trematode of the genus Paragonimus(1,2). Infestation is rare in Spain, but the influx of people from endemic areas should make us keep this condition in the differential diagnosis of our patients(2,5). We report the case a patient from Ecuador and resident in Spain for 7 years with active pulmonary tuberculosis on arrival in Spain and later diagnosed with of pulmonary paragonimiasis due to persistent haemoptysis. The diagnosis was established by surgical lung specimen showing granulomas containing parasite eggs and the macroscopic view of the fluke within a lung cavity. Initial tuberculosis treatment and current treatment with praziquantel controlled both conditions.

Topics: Adult; Animals; Anthelmintics; Antitubercular Agents; Caulobacteraceae; Delayed Diagnosis; Ecuador; Ethambutol; Food Parasitology; Gram-Negative Bacterial Infections; Granuloma; Hemoptysis; Humans; Isoniazid; Lung Diseases, Parasitic; Male; Paragonimiasis; Pneumonia, Bacterial; Praziquantel; Pyrazinamide; Radiography; Rifampin; Spain; Tuberculosis, Pulmonary

There are currently no defined optimal therapies available for multidrug-resistant (MDR) Acinetobacter baumannii infections. We evaluated the efficacy of rifampin, imipenem, sulbactam, colistin, and their combinations against MDR A. baumannii in experimental pneumonia and meningitis models. The bactericidal in vitro activities of rifampin, imipenem, sulbactam, colistin, and their combinations were tested using time-kill curves. Murine pneumonia and rabbit meningitis models were evaluated using the A. baummnnii strain Ab1327 (with MICs for rifampin, imipenem, sulbactam, and colistin of 4, 32, 32, and 0.5 mg/liter, respectively). Mice were treated with the four antimicrobials and their combinations. For the meningitis model, the efficacies of colistin, rifampin and its combinations with imipenem, sulbactam, or colistin, and of imipenem plus sulbactam were assayed. In the pneumonia model, compared to the control group, (i) rifampin alone, (ii) rifampin along with imipenem, sulbactam, or colistin, (iii) colistin, or (iv) imipenem plus sulbactam significantly reduced lung bacterial concentrations (10.6 +/- 0.27 [controls] versus 3.05 +/- 1.91, 2.07 +/- 1.82, 2.41 +/- 1.37, 3.4 +/- 3.07, 6.82 +/- 3.4, and 4.22 +/- 2.72 log(10) CFU/g, respectively [means +/- standard deviations]), increased sterile blood cultures (0% versus 78.6%, 100%, 93.3%, 93.8%, 73.3%, and 50%), and improved survival (0% versus 71.4%, 60%, 46.7%, 43.8%, 40%, and 85.7%). In the meningitis model rifampin alone or rifampin plus colistin reduced cerebrospinal fluid bacterial counts (-2.6 and -4.4 log(10) CFU/ml). Rifampin in monotherapy or with imipenem, sulbactam, or colistin showed efficacy against MDR A. baumannii in experimental models of pneumonia and meningitis. Imipenem or sulbactam may be appropriate for combined treatment when using rifampin.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Colistin; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Humans; Imipenem; Meningitis, Bacterial; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rabbits; Rifampin; Sulbactam; Treatment Outcome

We performed urinary antigen tests for pneumococcus and Legionella for patients with community-acquired pneumonia (CAP), to prescribe a documented antibiotic therapy. We report the efficiency of low-spectrum antibiotic treatment, illustrating the inappropriateness of bacteriological respiratory sampling.. Patients with CAP were enrolled from three different units; the pneumonia severity index was used to assess the disease. Respiratory samples were also listed. Low-spectrum antibiotic therapy was amoxicillin for pneumococcal infection, and macrolides or non-anti-pneumococcal fluoroquinolone for legionellosis.. Six hundred and seventy-five CAP were diagnosed during the study period,, 150 with positive urinary antigen tests (23%), among which 108 pneumococcal infections (73%), 40 legionellosis (26%), and two mixed infections. The pneumonia severity index was 106+/-38. Amoxicillin was prescribed in 108 cases, fluoroquinolone in 24 cases, macrolide in 18 cases. The outcome was favourable for 138 patients (92%). Eighty three respiratory samples allowed identification of a bacterium for 58 patients (39%), among which 24 strains were not in the antibiotic spectrum: Haemophilus influenzae and Pseudmomonas aeruginosa in six cases, Staphylococcus aureus in five cases, Klebsiella pneumoniae in two cases, and another Gram negative bacillus in five cases. These strains were resistant in vitro to the prescribed treatment in 19/24 cases (79%). One out of 12 patients who died had a respiratory sample positive for Enterobacter spp strain resistant to the ongoing antibiotic treatment.. The low-spectrum antibiotic therapy based on urinary antigen tests is efficient, and demonstrates respiratory tract colonisation with bacteriological strains usually considered as pathogenic.

Topics: Aged; Aged, 80 and over; Amoxicillin; Anti-Bacterial Agents; Antigens, Bacterial; Cohort Studies; Community-Acquired Infections; Comorbidity; Erythromycin; Female; France; Hospital Mortality; Hospitals, University; Humans; Legionella; Legionnaires' Disease; Lung Diseases, Fungal; Male; Middle Aged; Ofloxacin; Pneumonia, Bacterial; Pneumonia, Pneumococcal; Rifampin; Severity of Illness Index; Streptococcus pneumoniae; Treatment Outcome

Acinetobacter baumannii is an important cause of nosocomial infection with increasing carbapenem resistance. The aim of this study was to compare the efficacy of colistin+rifampicin and imipenem+rifampicin combinations with that of several other antibiotic regimens against carbapenem-resistant A. baumannii pneumonia using an immunosuppressed mouse model. Three different A. baumannii strains with diverse resistance mechanisms (OXA-51-, IMP-1- and VIM-2-type beta-lactamases) were used. Among the monotherapy regimens, only rifampicin significantly reduced the bacterial load in lungs 24 h after infection with the OXA-51-producing strain. Addition of rifampicin to either imipenem or colistin yielded synergistic results after 48 h. Rifampicin was bactericidal against the IMP-1-producing strain, and only the imipenem+rifampicin combination yielded synergistic effects. In contrast, rifampicin alone was not effective against the VIM-2-producing strain, but the imipenem+rifampicin combination was bacteriostatic even at 24 h post-infection. Tigecycline and amikacin were not effective against any of the three strains. Rifampicin-based combinations were effective against A. baumannii bacteraemia and improved survival regardless of the strain type. Contrary to the similar minimum inhibitory concentration results, the antibacterial effects of rifampicin were quite different according to the strains; a tailored antibiotic strategy must be considered in treatment. Addition of rifampicin to either imipenem or colistin would be effective.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Anti-Bacterial Agents; Carbapenems; Colistin; Disease Models, Animal; Drug Resistance, Bacterial; Drug Therapy, Combination; Female; Humans; Imipenem; Immunosuppression Therapy; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Neutropenia; Pneumonia, Bacterial; Rifampin; Treatment Outcome

Brucellosis is primarily a zoonotic disease that continues to be an important public health problem. It is a rare, multisystem infection of childhood and it may present with a wide spectrum of clinical presentations and complications. However, lung involvement is extremely rare in the course of childhood brucellosis. This case report describes a 6-year-old child who was referred to our hospital as meningococcemia but diagnosed as lobar pneumonia in follow-up. Brucella agglutination test and bone marrow culture were diagnostic of brucellosis. The patient responded to the combination therapy of rifampicin and trimethoprim-sulfamethoxazole.

Topics: Anti-Bacterial Agents; Brucella; Brucellosis; Child; Female; Humans; Pneumonia, Bacterial; Rifampin; Trimethoprim, Sulfamethoxazole Drug Combination

Lung disease due to mycobacterium avium complex (MAC) is being increasingly recognized. The clinical and radiological manifestations are varied and treatment is complex. We present two cases of MAC-induced lung disease to illustrate this disease.

Topics: Aged; Azithromycin; Bronchoalveolar Lavage Fluid; Drug Therapy, Combination; Ethambutol; Female; Humans; Middle Aged; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Pneumonia, Bacterial; Rifampin; Tomography, X-Ray Computed; Treatment Outcome

Topics: Acinetobacter baumannii; Acinetobacter Infections; Adult; Aged; Anti-Bacterial Agents; Colistin; Combined Modality Therapy; Cross Infection; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Pneumonia, Bacterial; Respiration, Artificial; Rifampin

Topics: Abscess; Actinomycetales Infections; Animals; Anti-Bacterial Agents; Azithromycin; Diagnosis, Differential; Horse Diseases; Horses; Lung; Male; Pneumonia, Bacterial; Radiography, Thoracic; Rhodococcus equi; Rifampin; Ultrasonography

To examine the development of rifampicin resistance in multidrug-resistant Acinetobacter baumannii exposed to rifampicin and the prevention of the appearance of rifampicin-resistant mutants when rifampicin is used in association with imipenem or sulbactam.. A clinical strain of multidrug-resistant A. baumannii was used to examine the frequency of resistance to rifampicin in vivo, in a pneumonia model in immunocompetent C57BL/6 mice. The in vitro and in vivo prevention of the development of resistance to rifampicin was analysed using rifampicin alone or in association with imipenem or sulbactam, in time-kill studies and in the experimental murine pneumonia, respectively.. Rifampicin-resistant mutants were found at 48 and 72 h, both in vitro and in vivo, when rifampicin was used alone, with the MIC increasing from 4 to > or =128 mg/L. The in vivo frequency of rifampicin-resistant mutants was 3 x 10(-6). On the contrary, no resistant mutants appeared after 72 h, in vitro or in vivo, when rifampicin was employed in association with imipenem or sulbactam. After six daily passages in rifampicin-free agar plates the resistant mutants maintained the high resistance to rifampicin (> or =128 mg/L).. These results suggest that rifampicin must not be used alone in the treatment of infections caused by multidrug-resistant A. baumannii. In these cases, rifampicin may be used in combination with imipenem or sulbactam, which prevent the development of resistance to rifampicin.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Anti-Bacterial Agents; Disease Models, Animal; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Imipenem; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Mutation; Pneumonia, Bacterial; Rifampin; Sulbactam

Nontuberculous mycobacteria (NTM) are increasingly recognized as important pulmonary pathogens. Mycobacterium avium intracellulare complex (MAC) causes most lung infections due to NTM. Patients with preexisting lung disease or immunodeficiency are at greatest risk for developing MAC infection. The majority of MAC pulmonary cases, however, occur in immunocompetent elderly women in association with nodular infiltrates and bronchiectasis. More recently, pulmonary disease has also been described in immunocompetent patients after exposure to MAC-contaminated hot tubs. We describe a case of aggressive MAC lung disease in a young immunocompetent female patient without preexisting lung disease whose clinical and pathologic characteristics do not fit into any of these categories and may represent a unique manifestation of MAC lung disease.

Topics: Adult; Amikacin; Biopsy; Clarithromycin; Diagnosis, Differential; Drug Therapy, Combination; Ethambutol; Female; Granuloma; Humans; Lung; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Necrosis; Pneumonia, Bacterial; Prednisone; Rifampin; Sputum; Tomography, X-Ray Computed

A 3-month-old female Arabian horse was evaluated because of fever, respiratory distress, lethargy, and decreased appetite of 5 days' duration. Pleural effusion was diagnosed on the basis of ultrasonographic and radiographic examinations. Cytologic examination of pleural fluid collected via thoracocentesis revealed septic inflammation; bacteriologic culture of a sample of that fluid yielded Rhodococcus equi. A large intra-abdominal mass adjacent to the body wall was identified ultrasonographically. A specimen of the mass was collected via aspiration; the specimen was identified cytologically as purulent exudate that contained large numbers of rod-shaped bacteria, which confirmed abdominal abscess formation. Bacteriologic culture of a sample of the exudate also yielded R. equi. The foal was treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 24 h for 5 days then q 48 h) and rifampin (5 mg/kg [2.3 mg/lb], PO, q 12 h) for 8 weeks and metronidazole (15 mg/kg [6.8 mg/lb], PO, q 8 h) for 3 weeks. Clinically, the foal responded to antimicrobial treatment within 2 weeks. At 8 weeks after the initial evaluation, ultrasonographic examination of the foal revealed resolution of the pleural effusion and abdominal abscess. In foals, R. equi infection typically results in pyogranulomatous pneumonia, and pleural effusion is an uncommon clinical sign. The combination of azithromycin and rifampin appears to be an effective treatment for R. equi infection in foals.

Topics: Abdominal Abscess; Actinomycetales Infections; Animals; Animals, Newborn; Anti-Bacterial Agents; Azithromycin; Drug Resistance, Bacterial; Female; Horse Diseases; Horses; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Treatment Outcome; Ultrasonography

Acinetobacter baumannii is a well-known cause of hospital-acquired pneumonia. Occasionally, it can present as an acute community-acquired pneumonia with a fulminant course. However, the occurrence of the chronic form of community-acquired Acinetobacter pneumonia is yet to be highlighted. We describe a 62-year-old, HIV negative, non-diabetic male, who was referred for evaluation of consolidation and cavitation in the apicoposterior segment of the left upper lobe for 4 months. For this, he had received anti-tuberculous therapy, which included rifampicin. On investigation, a diagnosis of chronic community-acquired pneumonia due to Acinetobacter baumannii was made. The steady clinico-radiologic improvement observed was attributed to rifampicin in the anti-tuberculous regime. Subsequently, an aspergilloma formed in the cavity.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Antibiotics, Antitubercular; Chronic Disease; Community-Acquired Infections; Humans; Male; Pneumonia, Bacterial; Rifampin; Time Factors; Treatment Outcome

Legionella species other than Legionella pneumophila may cause pneumonias and extrapulmonary infections. Most infections are nosocomial or observed in immunocompromised patients and often remain undiagnosed because of the failure of confirmatory culture methods. The therapy is based on macrolides and fluoroquinolones; rifampin and tetracycline are also used.

Topics: Anti-Bacterial Agents; Cross Infection; Fluoroquinolones; Humans; Immunocompromised Host; Legionella; Legionellosis; Macrolides; Pneumonia, Bacterial; Rifampin; Tetracycline

Successful therapy of carbapenem-resistant Acinetobacter baumannii strains has been reported with colistin, but recently we argued against its use as monotherapy because of the poor results obtained in a mouse pneumonia model. Our aim was to identify antibiotic combinations that were valid therapeutic alternatives in the same model.. We used two carbapenem-resistant A. baumannii strains (D and E; MICs of imipenem, 8 and 512 mg/L, respectively). MICs of tobramycin, rifampicin and colistin for both strains were 8, 8 and 0.5 mg/L, respectively.. In infections caused by strain D, lung bacterial counts (log(10) cfu/g, mean +/- s.d.) were: controls (10.86+/-0.25), imipenem (5.99+/-0.59, P < 0.05 versus controls), and colistin (10.43 +/- 1.09); imipenem + tobramycin was the most active combination (5.46+/-0.62, P < 0.05 versus controls). In infections caused by strain E, results were: controls (10.82+/-0.33), rifampicin (5.62+/-0.26, P < 0.05 versus controls), colistin (8.38+/-1.22, P < 0.05 versus controls), and imipenem (11.01+/-0.2); rifampicin + imipenem (3.79+/-0.99) and rifampicin + tobramycin (3.96+/-0.30) were the most active combinations (P < 0.05); results with rifampicin + colistin (5.59+/-1.17) were similar to those with rifampicin alone.. Our data indicate that imipenem can still be the best alternative for carbapenem-resistant A. baumannii infections with moderate levels of imipenem resistance, preferably combined with aminoglycosides. For strains highly resistant to imipenem, a combination of rifampicin with imipenem, tobramycin or colistin may be useful, if resistance to rifampicin is only moderate.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Anti-Bacterial Agents; beta-Lactams; Carbapenems; Colistin; Disease Models, Animal; Drug Resistance, Bacterial; Drug Therapy, Combination; Female; Humans; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin; Tobramycin

To investigate most common pathogens isolated from the hospital-acquired pneumonia patients bronchoalveolar lavage fluid in Kaunas University of Medicine Hospital according to the previous antibiotic use and to estimate pathogens antibacterial susceptibility.. Results of 87 hospital-acquired pneumonia patients bronchoalveolar lavage fluid quantitative cultures were analyzed. Microorganisms isolated in clinically significant amount were considered as the etiological agents and included into analysis. Susceptibility was tested using the standard methods. Previously untreated patients were considered if the antibacterials were not administered at all or were used less than for 24 hours.. H. influenzae isolation in significant amount rates were higher in previously untreated patients group comparing to previously treated (29.2%. (n=14) and 5.1% (n=2), respectively, p<0.05). Non-fermenters (P. aeruginosa and Acinetobacter spp.) isolation rates were higher in those previously treated comparing to untreated patients - (31.0% (n=13) and 4.2% (n=2), respectively, p<0.05). All H. influenzae strains were susceptible to ampicillin and cefuroxime. 22.2-44.4% of P. aeruginosa strains were resistant to ceftazidime, amikacin and ciprofloxacin. Estimated Acinetobacter spp. resistance to ciprofloxacin and gentamycin was 83.3% and to ampicillin/sulbactam - 16.7%. All methicillin-susceptible S.aureus were also susceptible to gentamycin and fucidin and methicillin resistant to rifampicin and vancomycin.. Previous antibiotic treatment has an impact on pneumonia etiology testing. H. influenzae strains are more common isolated hospital-acquired pneumonia etiologic agents in previously untreated patients. The low antibacterial resistance was found enabling the use of aminopenicillins for treatment if H. influenzae infection suggested. The use of antibacterials increases non-fermenters isolation rates and combined antipseudomonal treatment is reasonable in these patients.

Topics: Acinetobacter; Acinetobacter Infections; Amikacin; Ampicillin; Anti-Bacterial Agents; Anti-Infective Agents; Bacteria; Bronchoalveolar Lavage Fluid; Ceftazidime; Cefuroxime; Ciprofloxacin; Cross Infection; Drug Resistance, Bacterial; Drug Therapy, Combination; Female; Fusidic Acid; Gentamicins; Haemophilus Infections; Haemophilus influenzae; Humans; Male; Methicillin; Microbial Sensitivity Tests; Middle Aged; Penicillins; Pneumonia, Bacterial; Pneumonia, Staphylococcal; Pseudomonas aeruginosa; Pseudomonas Infections; Rifampin; Staphylococcus aureus; Sulbactam; Vancomycin Resistance

The antimicrobial susceptibilities of 30 Rhodococcus equi isolates obtained from 30 patients between 1993 and 2001 in northern Thailand were investigated. The MICs showed a tendency toward resistance to various antibiotics but sensitivity to imipenem, minocycline, vancomycin, and teicoplanin (MICs, /=64 micro g/ml) to rifampin. PCR amplification and DNA sequencing of the rpoB gene and molecular typing by pulsed-field gel electrophoresis (PFGE) were performed for eight R. equi isolates from eight AIDS patients with pneumonia or lung abscess caused by R. equi between 1998 and 2001, including one low- and three high-level rifampin-resistant isolates. As a result, two high-level rifampin-resistant strains with PFGE pattern A had a Ser531Trp (Escherichia coli numbering) mutation, and one high-level rifampin-resistant strain with PFGE pattern B had a His526Tyr mutation, whereas one low-level rifampin-resistant strain with PFGE pattern C had a Ser509Pro mutation. Four rifampin-susceptible strains with PFGE patterns D and E showed an absence of mutation in the rpoB region. Our results indicate the presence of several types of rifampin-resistant R. equi strains among AIDS patients in northern Thailand.

Topics: Actinomycetales Infections; Adult; AIDS-Related Opportunistic Infections; Animals; Antibiotics, Antitubercular; DNA-Directed RNA Polymerases; Drug Resistance, Bacterial; Female; Humans; Lung Abscess; Male; Microbial Sensitivity Tests; Mutation; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Thailand

TNF-deficient mice are highly susceptible to Mycobacterium tuberculosis H37Rv infection. Here we asked whether TNF is required for postinfectious immunity in aerosol-infected mice. Chemotherapy for 4 wk commencing 2 wk postinfection reduced CFU to undetectable levels. While wild-type mice had a slight rise in CFU, but controlled infection upon cessation of chemotherapy, TNF-deficient mice developed reactivation of infection with high bacterial loads in lungs, spleen, and liver, which was fatal within 13-18 wk. The increased susceptibility of TNF-deficient mice was accompanied by diminished recruitment and activation of T cells and macrophages into the lung, with defective granuloma formation and reduced inducible NO synthase expression. Reduced chemokine production in the lung might explain suboptimal recruitment and activation of T cells and uncontrolled infection. Therefore, despite a massive reduction of the mycobacterial load by chemotherapy, TNF-deficient mice were unable to compensate and mount a protective immune response. In conclusion, endogenous TNF is critical to maintain latent tuberculosis infection, and in its absence no specific immunity is generated.

Topics: Animals; Cell Migration Inhibition; Chemokines; Down-Regulation; Granuloma; Isoniazid; Lymphocyte Activation; Lymphocyte Subsets; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mycobacterium tuberculosis; Necrosis; Pneumonia, Bacterial; Recurrence; Rifampin; Tuberculosis, Pulmonary; Tumor Necrosis Factor-alpha

A one-year-and-seven-months-old boy was hospitalised because of fever, cough and general malaise. A diagnosed tonsillitis and pneumonia were treated with intravenous antibiotics. His clinical condition worsened despite antibiotic therapy. After immunologic investigations revealed both a cellular and a humoral immune disorder, a broncho-alveolar lavage was performed. The culture revealed Legionella pneumophila. Antibiotic treatment was then changed to erythromycin in combination with rifampicin, with a good response. Although rarely described in childhood, one should consider L. pneumophila as a possible pathogen in immunocompromised children presenting with pneumonia.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Bronchoalveolar Lavage Fluid; Drug Therapy, Combination; Erythromycin; Fluoroquinolones; Humans; Immunocompromised Host; Infant; Legionella pneumophila; Legionnaires' Disease; Male; Pneumonia, Bacterial; Rifampin; Treatment Outcome

Parachlamydia acanthamoeba are intracellular bacteria of amoebae and are considered potential etiological agents of human pneumonia. We have determined the in vitro antibiotic susceptibilities of two strains (strain Bn(9) and Hall's coccus) in Acanthamoeba polyphaga. The two strains were susceptible to tetracyclines, macrolides, and rifampin, but resistant to fluoroquinolones.

Topics: Acanthamoeba; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Bacteria; DNA, Bacterial; Drug Resistance, Bacterial; Fluoroquinolones; Humans; Macrolides; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin; Tetracyclines

The treatment of life-threatening infections due to carbapenem-resistant Acinetobacter baumannii has become a serious challenge for physicians worldwide. Often, only colistin shows in general good in vitro activity against these carbapenem-resistant strains, but its antibacterial efficacy in comparison with the antibiotics most used in clinical practice is not well known. We studied the efficacy of colistin versus those of imipenem, sulbactam, tobramycin, and rifampin in an experimental pneumonia model with immunocompetent mice. We used three strains of A. baumannii corresponding to the main clones (A, D, and E) involved in the outbreaks of our hospital, with different grades of resistance to imipenem (imipenem MICs of 1, 8, and 512 microg/ml, respectively) and to the other antibiotics. The MIC of colistin was 0.5 microg/ml for the three strains. Reduction of log(10) CFU/g in lung bacterial counts, clearance of bacteremia, and survival versus results with controls were used as parameters of efficacy. Imipenem and sulbactam (Deltalung counts: -5.38 and -4.64 log(10) CFU/ml) showed the highest level of bactericidal efficacy in infections by susceptible and even intermediate strains. Tobramycin and rifampin (-4.16 and -5.15 log(10) CFU/ml) provided good results against intermediate or moderately resistant strains, in agreement with killing curves and pharmacodynamics. On the contrary, colistin showed the weakest antibacterial effect among the antibiotics tested, both in killing curves and in the in vivo model (-2.39 log(10) CFU/ml; P < 0.05). We conclude that colistin did not appear as a good option for treatment of patients with pneumonia due to carbapenem-resistant A. baumannii strains. Other alternatives, including combinations with rifampin, may offer better therapeutic profiles and thus should be studied.

Topics: Acinetobacter; Acinetobacter Infections; Aminoglycosides; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Microbial; Female; Lung; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin; Survival Analysis

Treatment with a combination of erythromycin and rifampin has considerably improved survival rates of foals and immunocompromised patients suffering from severe pneumonia caused by Rhodococcus equi. Frequently, because of monotherapy, emergence of rifampin-resistant strains has been responsible for treatment failure. Using consensus oligonucleotides, we have amplified and sequenced the rifampin resistance (Rif(r))-determining regions of 12 rifampin-resistant R. equi strains isolated from three foals and of mutants selected in vitro from R. equi ATCC 3701, a rifampin-susceptible strain. The deduced amino acid sequences compared to those of four rifampin-susceptible R. equi strains showed several types of mutations. In 3 of the 10 strains isolated from one foal, His526Asn (Escherichia coli numbering) and Asp516Val mutations were associated with low-level resistance (rifampin MIC, 2 to 8 microg/ml), whereas His526Asp conferred high-level resistance (rifampin MIC, 128 microg/ml) in the 7 remaining strains. In strains from the two other foals, His526Asp and Ser531Leu mutations were found to be associated with high-level and low-level resistance, respectively. The in vitro mutants, highly resistant to rifampin, harbored His526Tyr and His526Arg substitutions. As described in other bacterial genera, His526, Ser531, and Asp516 are critical residues for rifampin resistance in R. equi, and the resistance levels are dependent on both the location and the nature of the substitution.

Topics: Actinomycetales Infections; Animals; Antibiotics, Antitubercular; DNA-Directed RNA Polymerases; Drug Resistance, Bacterial; Horse Diseases; Horses; Microbial Sensitivity Tests; Mutation; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Sequence Analysis, DNA

Diagnosis of pneumonia caused by Rhodococcus equi can be made more rapidly by use of a polymerase chain reaction (PCR) assay than by use of conventional bacteriologic culture techniques. Use of a PCR assay aids in the differentiation between virulent and avirulent strains of R equi, and the assay may be used to identify R equi in feces and soil of breeding farms.

Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Erythromycin; Female; Gentamicins; Horse Diseases; Horses; Leukocyte Count; Penicillins; Platelet Count; Pneumonia, Bacterial; Polymerase Chain Reaction; Radiography, Thoracic; Rhodococcus equi; Rifampin; Virulence

The effects of various regimens containing combinations of beta-lactams, beta-lactam inhibitor(s), and rifampin were assessed in a recently described mouse model of Acinetobacter baumannii pneumonia (M. L. Joly-Guillou, M. Wolff, J. J. Pocidalo, F. Walker, and C. Carbon, Antimicrob. Agents Chemother. 41:345-351, 1997). Two aspects of the therapeutic response were studied: the kinetics of the bactericidal effect (treatment was initiated 3 h after intratracheal inoculation, and bacterial counts were determined over a 24-h period) and survival (treatment was initiated 8 h after inoculation, and the cumulative mortality rate was assessed on day 5). Two clinical strains were used: a cephalosporinase-producing strain (SAN-94040) and a multiresistant strain (RCH-69). For SAN-94040 and RCH-69, MICs and MBCs (milligrams per liter) were as follows: ticarcillin, 32, 64, 256, and >256, respectively; ticarcillin-clavulanate, 32, 64, and 512, and >512, respectively; imipenem, 0.5, 0.5, 8, and 32, respectively; sulbactam, 0.5, 0.5, 8, and 8, respectively; and rifampin, 8, 8, 4, and 4, respectively. Against SAN-94040, four regimens, i.e., imipenem, sulbactam, imipenem-rifampin, and ticarcillin-clavulanate (at a 25/1 ratio)-sulbactam produced a true bactericidal effect (>/=3-log10 reduction of CFU/g of lung). The best survival rate (i.e., 93%) was obtained with the combination of ticarcillin-clavulanate-sulbactam, and regimens containing rifampin provided a survival rate of >/=65%. Against RCH-69, only regimens containing rifampin and the combination of imipenem-sulbactam had a true bactericidal effect. The best survival rates (>/=80%) were obtained with regimens containing rifampin and sulbactam. These results suggest that nonclassical combinations of beta-lactams, beta-lactamase inhibitors, and rifampin should be considered for the treatment of nosocomial pneumonia due to A. baumannii.

Topics: Acinetobacter; Acinetobacter Infections; Animals; Anti-Bacterial Agents; beta-Lactamase Inhibitors; beta-Lactams; Drug Therapy, Combination; Enzyme Inhibitors; Female; Mice; Mice, Inbred C3H; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin

Azithromycin, doxycycline, and rifampin, alone or in combination, were tested in vitro against Chlamydia pneumoniae AR-39. The combination of azithromycin plus rifampin showed the strongest activity and produced higher rates of eradication of C. pneumoniae from lung tissues than azithromycin alone in experimental mouse pneumonitis.

Topics: Animals; Azithromycin; Chlamydia Infections; Chlamydophila pneumoniae; DNA, Bacterial; Drug Therapy, Combination; Lung; Male; Mice; Pneumonia, Bacterial; Rifampin

In Sweden, mares sometimes develop acute, often fatal, colitis when their foals are treated orally with erythromycin and rifampicin for Rhodococcus (R.) equi infection. Clostridium (C.) difficile, or its cytotoxin, was demonstrated in faecal samples from 5 of 11 (45%) mares with diarrhoea. By contrast C. difficile was not found in the faecal flora of 12 healthy mares with foals treated for R. equi infection or in 56 healthy mares with healthy untreated foals. No other enteric pathogen was isolated from any diarrhoeic mare. Of 7 investigated treated foals, 4 had a high (1651.0, 1468.3, 273.0 and 88.8 microg/g) faecal concentration of erythromycin. The dams of those 4 foals developed acute colitis, whereas the dams of 3 foals with a lower (26.3, 4.6 and 3.7 microg/g) faecal erythromycin concentration remained healthy, indicating that there might have been an accidental intake of erythromycin by mares. The foals treated with antibiotics were regarded as asymptomatic carriers and potential reservoirs, as C. difficile was found in 7 of 16 foals investigated, while 56 untreated foals proved negative. The isolated C. difficile strains proved resistant to both erythromycin (MIC>256 mg/l) and rifampicin (MIC>32 mg/l), a fact that may have favoured the growth of C. difficile in the foal intestine. All mares found positive for C. difficile were, or had recently been, hospitalised together with their foals, indicating that C. difficile may be a nosocomial infection, in horses. The results emphasise that routine testing for C. difficile and its cytotoxin is recommended when acute colitis occurs in mares when their foals are treated with erythromycin and rifampicin. Preventive measures in order to avoid accidental ingestion of erythromycin by mares from the treatment of their foals are suggested.

Topics: Actinomycetales Infections; Acute Disease; Animals; Animals, Suckling; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Toxins; Clostridioides difficile; Cytotoxins; Drug Resistance, Microbial; Drug Therapy, Combination; Enterocolitis, Pseudomembranous; Erythromycin; Feces; Female; Horse Diseases; Horses; Pneumonia, Bacterial; Rhodococcus equi; Rifampin

Topics: Actinomycetales Infections; Adult; AIDS-Related Opportunistic Infections; Ciprofloxacin; Clarithromycin; Diagnostic Errors; Drug Therapy, Combination; Humans; Mycobacterium Infections; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Vancomycin

Legionella jordanis has seldom been reported as a cause of infection in humans. We describe a case of pneumonia due to L. jordanis that occurred in a non-immunocompromised 74-year-old patient and failed to respond to a combination of ceftriaxone and ofloxacin. Cure was achieved only after an erythromycin-rifampin combination was started.

Topics: Aged; Anti-Infective Agents; Ceftriaxone; Drug Therapy, Combination; Erythromycin; Humans; Immunocompetence; Legionella; Legionellosis; Male; Ofloxacin; Pneumonia, Bacterial; Rifampin

Topics: Actinomycetales Infections; Adult; AIDS-Related Opportunistic Infections; Ciprofloxacin; Clarithromycin; Drug Resistance, Microbial; Drug Resistance, Multiple; Drug Therapy, Combination; Erythromycin; Gentamicins; Humans; Male; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Vancomycin

To study the characteristics of pulmonary tuberculosis complicated with legionnaires disease (LD) to avoid misdiagnosis and incorrect treatment.. Nine cases of pulmonary tuberculosis complicated with LD were retrospectively analyzed.. The clinical and chest X-ray manifestations varied, and no characteristics were found in these cases. Because cross antibodies existed between Legionella pneumophila and other causal bacteria, it was found difficult to differentiate LD, pulmonary tuberculosis and other causal bacteria infection. Efficacy of erythromycin combined with rifampicin, and decrease of serum titres of Legionella pneumophila four times after treatment were found helpful for definite diagnosis of LD.. Only paying much attention to LD, and detecting the serum antibody as early as possible can provide evidence for diagnosing of the disease.

Topics: Adult; Aged; Anti-Bacterial Agents; Antitubercular Agents; Drug Therapy, Combination; Erythromycin; Female; Humans; Legionnaires' Disease; Male; Middle Aged; Pneumonia, Bacterial; Retrospective Studies; Rifampin; Tuberculosis, Pulmonary

In the past, Mycobacterium avium complex (MAC) was considered a colonizing microbe in the immunocompetent host. Today it should be considered a potential pathogen. We present a case of MAC necrotizing pneumonia in a 27-year-old man who tested negatively for the human immunodeficiency virus, had no typical granulomas, and responded rapidly to antimicrobial therapy.

Topics: Adult; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Antitubercular Agents; Ciprofloxacin; Clarithromycin; Drug Therapy, Combination; Ethambutol; HIV Seronegativity; Humans; Male; Mycobacterium avium-intracellulare Infection; Necrosis; Pneumonia, Bacterial; Pulmonary Atelectasis; Rifampin

Topics: Anti-Bacterial Agents; Corynebacterium; Corynebacterium Infections; Humans; Microbial Sensitivity Tests; Pneumonia, Bacterial; Rifampin; Teicoplanin; Vancomycin

Infections of Rhodococcus equi, a well-known pathogen in animals which causes cavitated pneumonia similar to that caused by mycobacteria, were studied in three HIV-infected patients. This microorganism was isolated in the bronchoalveolar washings of two patients and in the sputum of the third. In two patients, Rh. equi represented the first clinical opportunistic manifestation of HIV disease. One patient died of concomitant Pneumocystis infection. The eradication of the microorganism occurred in two out of three patients. It was found that no isolates were resistant to erythromycin, claritromycin, rifampin, vancomycin, teicoplanin, imipenem, gentamycin or azithromycin (MIC values < or = 0.1 microgram/ml). Moreover, the quinolones (ciprofloxacin and ofloxacin) were found to be less effective, whereas neither the beta-lactam antibiotics nor chloramphenicol were effective therapy for this microrganism. At least two antimicrobial agents should be given contemporaneously to treat these infections for a period of up to several months. Our results suggest that the combinations erythromycin + rifampin or imipenem + teicoplanin are the most effective treatments in Rh. equi infections.

Topics: Actinomycetales Infections; Adult; AIDS-Related Opportunistic Infections; Anti-Bacterial Agents; Azithromycin; Bacteremia; Bronchoalveolar Lavage Fluid; Clarithromycin; Drug Resistance, Microbial; Drug Synergism; Drug Therapy, Combination; Erythromycin; Female; Gentamicins; HIV Infections; Humans; Imipenem; Male; Pleurisy; Pneumonia, Bacterial; Rhodococcus equi; Rifampin; Sputum; Teicoplanin; Vancomycin

In three patients, men of 30, 21 and 24 years old respectively, Rhodococcus equi pneumonia was diagnosed. Antibiotic treatment, followed by secondary prophylaxis, was successful. In one patient, lobectomy was done. R. equi, a well-known bacterial pathogen in horses, appears also to be pathogenic in humans in case of immunodeficiency.

Topics: Actinomycetales Infections; Adult; AIDS-Related Opportunistic Infections; Drug Therapy, Combination; Erythromycin; Humans; Immunocompromised Host; Male; Pneumonia, Bacterial; Rhodococcus equi; Rifampin

Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Arthritis, Reactive; Drug Resistance, Microbial; Drug Therapy, Combination; Erythromycin; Female; Horse Diseases; Horses; Lung; Pneumonia, Bacterial; Rheumatoid Factor; Rhodococcus equi; Rifampin; Synovial Fluid