sultamicillin and Pseudomonas-Infections

Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacteria and an opportunistic pathogen in humans and animals. The present study was carried out to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment.. A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, the West of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exoA, exoS, exoU, and algD using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method.. The results showed the prevalence of exoA 33 (56.9%), exoS 21 (36.20%), exoU 37 (63.8%), and algD 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exoS 25 (43.1%), exoU 40(68.98%), and algD 25 (43.1%) genes in clinical isolates of P. aeruginosa. High resistance levels of the clinical and ICU environment isolate to ampicillinsulbactam (100%), were also observed.. Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.

Topics: Ampicillin; Anti-Bacterial Agents; Bacterial Proteins; Disk Diffusion Antimicrobial Tests; Drug Resistance, Multiple, Bacterial; Environmental Microbiology; Humans; Intensive Care Units; Iran; Polymerase Chain Reaction; Pseudomonas aeruginosa; Pseudomonas Infections; Sulbactam; Virulence Factors

Ampicillin-sulbactam is guideline-recommended treatment for early-onset ventilator-associated pneumonia (VAP). However, intensive care unit clinicians are encountering increasing resistance to ampicillin-sulbactam. We sought to analyze the time period for early-onset VAP in our trauma population by using daily evaluation of resistance to ampicillin-sulbactam.. A retrospective cohort study was completed on all mechanically ventilated trauma patients admitted to a rural level-1 trauma center from January 2003 to December 2008 who were diagnosed with VAP. Daily bacterial resistance to ampicillin-sulbactam > 15% was defined as the threshold for early empiric antibiotic failure for the first episode of VAP. A univariate analysis of risk factors for multi-drug resistant pathogens (MDRPs) and comorbidities was completed to assess for predisposing factors for ampicillin-sulbactam resistance.. One hundred sixty-three pathogens were identified in 121 trauma patients diagnosed with VAP. Of these isolates, 71% were gram-negative, 28% were gram-positive, and 1% was fungal. Methicillin-susceptible Staphylococcus aureus (23.9%), H aemophilus influenzae (20.9%), and Pseudomonas aeruginosa (11.7%) were the most common infecting organisms. Daily ampicillin-sulbactam resistance was 40%, 26%, 32%, 43%, 50%, and 60% on days 3 to 7 and ≥ 8 days, respectively. Only the presence of MDRP risk factors (89% vs. 65%, p < 0.01) and hospital LOS (36.8 [22.8-49.0] vs. 25.7 days [19.0-32.5], p < 0.01) was different between ampicillin- sulbactam resistant and ampicillin-sulbactam susceptible VAP groups. On univariate analysis, hospital length of stay >4 days and antibiotic use within 90 days were associated with ampicillin-sulbactam resistant VAP (p < 0.01).. Ampicillin-sulbactam is not an effective empiric therapy for early-onset VAP in our rural trauma population. The utility of ampicillin-sulbactam should be reviewed at other institutions to assess for appropriate empiricism.

Topics: Adult; Aged; Ampicillin; Anti-Bacterial Agents; Bacterial Infections; Drug Resistance, Multiple, Bacterial; Female; Guideline Adherence; Haemophilus Infections; Haemophilus influenzae; Humans; Intensive Care Units; Male; Microbial Sensitivity Tests; Middle Aged; Pneumonia, Staphylococcal; Pneumonia, Ventilator-Associated; Pseudomonas aeruginosa; Pseudomonas Infections; Staphylococcus aureus; Sulbactam; Wounds and Injuries

After ertapenem was added to the formulary of a 344-bed community teaching hospital, we retrospectively studied its effect on antimicrobial utilization and on the in vitro susceptibility of various antimicrobial agents against Pseudomonas aeruginosa. Three study periods were defined as preintroduction (months 1 to 9), postintroduction but before the autosubstitution of ertapenem for ampicillin-sulbactam (months 10 to 18), and after the policy of autosubstitution (months 19 to 48) was initiated. Ertapenem usage rose slowly from introduction to a range of 36 to 48 defined daily doses/1,000 patient days (DDD) with a resultant decrease in ampicillin-sulbactam usage due to autosubstitution. Imipenem usage peaked 6 months after the introduction of ertapenem and started to decline coincidently with the increased use of ertapenem. During the second period, imipenem usage decreased (slope = -1.28; P = 0.002). Prior to the introduction of ertapenem, the susceptibility of P. aeruginosa to imipenem increased from 61 to 81% at month 7 but then decreased slightly to 67% at month 9. After the introduction of ertapenem, susceptibility continued to increase; the increasing trend was significant (slope = 1.74; P < 0.001). In the third period, the median susceptibility (interquartile range) was 88% (82 to 95%). This change appeared related to decreased imipenem usage. For every unit decrease in the monthly DDD of imipenem, there was an increase of 0.38% (P = 0.008) in the susceptibility of P. aeruginosa to imipenem in the same month. Ertapenem was effective in our antimicrobial stewardship program and may have helped improve the P. aeruginosa antimicrobial susceptibility to imipenem by decreasing the unnecessary usage and selective pressure of antipseudomonal agents.

Topics: Ampicillin; Anti-Bacterial Agents; beta-Lactams; Ertapenem; Formularies, Hospital as Topic; Humans; Imipenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Retrospective Studies; Sulbactam

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

To evaluate the potential bias of analyzing aggregated data, we separately examined antibiotic exposure and resistance data for 35,423 patients admitted to a university hospital in Utah, from both an individual-patient perspective and group-level perspective. From 1994 through 1998, use of defined daily doses (per 1000 patient-days) of fluoroquinolones, third-generation cephalosporins, ampicillin-sulbactam, and imipenem increased by 82%, 38%, and 99%, and decreased by 38%, respectively, whereas group-level resistance rates of Enterobacteriaceae or Pseudomonas species changed only minimally. However, in individual-patient-level analyses performed by multivariable proportional hazards regression, exposure to a fluoroquinolone, third-generation cephalosporin, ampicillin-sulbactam, or imipenem was a strong risk factor for resistance to fluoroquinolones (adjusted hazard ratio [AHR], 4.0; P<.001), third-generation cephalosporins (AHR, 3.5; P<.001), ampicillin-sulbactam (AHR, 2.3; P=.008), or imipenem (AHR, 5.7; P<.001), respectively. Thus, group-level and individual-patient-level analyses of antibiotic-use-versus-susceptibility relations yielded divergent results. Multicenter studies should include individual-patient-level data to elucidate more fully the relation between antibiotic exposure and resistance.

Topics: Ampicillin; Anti-Bacterial Agents; Cephalosporins; Cohort Studies; Drug Resistance, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Fluoroquinolones; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Imipenem; Male; Middle Aged; Pseudomonas; Pseudomonas Infections; Statistics as Topic; Sulbactam