250. Assessment of the prevalence of β-lactamase producing strains from Indian hospitalised patients and comparison of antimicrobial susceptibility using disc-diffusion method
Session: Poster Abstract Session: Antimicrobial Susceptibility and Resistance
Friday, October 21, 2011
Room: Poster Hall B1
  • Kochhar et al _ Assessment of the prevalence of -lactamase producing strains from Indian hospitals.pdf (1.2 MB)
  • Background: 

    The prevalence of antimicrobial resistance is increasing in India. Our previous two studies reported high levels of β– lactamase production & antibiotic resistance from India. 


    From 12 Indian centres, isolates from sterile and non-sterile sources were obtained from hospitalized patients. Antimicrobial susceptibility was determined by disc diffusion method andinterpretation was done according to standard CLSI criteria wherever applicable. β-lactamase production was assessed by CLSI methodology and nitrocefin test. 


    A total of 2039 isolates were obtained from hospitalized patients, maximum from intensive care unit (34.8%). E.coli (20.6%), Klebsiella (17.3%) and Pseudomonas aeruginosa (15.3%) were commonest isolates. Overall gram negative bacteria demonstrated a high rate of resistance to fluroquinolones (72%) and third generation cephalosporins (ceftazidime 67%). Carbapenems (meropenem: 75%), & β lactamase – β lactamase inhibiotors (BL-BLI) such as cefoperazone/sulbactam (71.9%) & piperacillin-tazobactam (68.7%) were reasonably active. Polymyxin B was the most active (99-100%) among the tested antibacterials. For gram positive bacteria linezolid was most effective (98%) followed by clindamycin and cefoperazone-sulbactam. β-lactamase production was more common amongst gram positive bacteria (86% ). ESBLs (extended spectrum β-lactamse) production was in 57.6% of Gram-negative isolates.


    The prevalence of β-lactamase production amongst gram negative isolates has declined as compared to 2000. However, resistance to many drugs has increased. This could possibly indicate evolution of alternate mechanisms of resistance amongst gram negative isolates. Resistance to third generation cephalosporins is highly prevalent and has increased. Carbapenems and BL-BLI are reasonably active against the majority of gram-negative bacteria though the highest sensitivity has been shown by Polymyxin B. Both classes could be good empirical choice in infections caused by gram-negative pathogens. However, high levels of resistance indicate that antibiotic selection should be guided by current local susceptibility patterns with monitoring and surveillance on a continuing basis.

    Subject Category: A. Antimicrobial agents and Resistance

    Puja Kochhar, Sanjay Somasundaram, Manmohan Singh and Egast Study Group, Pfizer, Mumbai, India


    P. Kochhar, Pfizer: Employee, Salary

    S. Somasundaram, Pfizer: Employee, Salary

    M. Singh, Pfizer: Employee, Salary

    E. Study Group, Pfizer: Investigator, Research grant

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.