PREVALENCE OF AmpC β LACTAMASES IN NON-FERMENTING GRAM NEGATIVE BACILLI FROM CLINICAL ISOLATES.

Abstract

Background and Objectives: Non fermenting gram negative bacilli (NFGNB) producing AmpC β lactamases an increasing cause of concern in the hospitals as they produce a therapeutic dilemma for the treating physician.The present study was undertaken to know the prevalence  of  AmpC β lactamases producing NFGNB from  clinical isolates and their antibiotic resistance pattern. Methods: A total of 389 NFGNBwere recovered from various clinical specimens. All the samples were processed for routine bacterial culture and antimicrobial susceptibility test as per standard protocol.They were further subjected to AmpC β-lactamase detection byCefoxitin disc test andAmpC disk test. Results: Cefoxitin resistance was observed in 92 (23.65%) isolates, of these 66 (16.96%) isolates were confirmed by AmpC disk test. Among Pseudomonas aeruginosa 26 (9.48%) were AmpC β-lactamase producing while among Acinetobacter species 40 (34.78%) are AmpC β-lactamase producing. Majority of AmpC β-lactamase producers were resistant to Gentamicin (80.3%), Levofloxacin (75.75%,) and Gatifloxacin (63.63%,) respectively. All isolates were sensitive to Polymyxin B. Conclusion: The prevalence of AmpC β-lactamase was 16.96% among NFGNB. Significantly higher resistance rate was observed by these isolates to almost all the drugs routinely used.

Key words: NFGNB, AmpC β-lactamase .Cefoxitin disc test, AmpC disk test.