Prevalence of nosocomial lower respiratory tract infections caused by Multi- drug resistance pathologens

Abstract

Introduction: Nosocomial infections caused by multi-drug resistant pathogens are major threat to the hospitalized patients. Extended spectrum beta-lactamase (ESBL) and metallo-beta-lactamase (MBL) producing bacterial strains causing hospital acquired lower respiratory tract infection are increasing in numbers. Only a limited number of studies related to MBL producers have been done in Nepal. Objective: The goal of this study was to determine the etiology of nosocomial lower respiratory tract infections and to assess the current levels of antimicrobial resistance with special reference to ESBL and MBL producing bacterial strains.

Methods: A total of 100 specimens including sputum and endotracheal secretion from patients diagnosed of nosocomial lower respiratory tract infection were collected and processed according to the standard methodology. Combination disk method was done for the detection of ESBL and MBL producing isolates.

Results: Out of total 100 specimens, 87% was monomicrobial while the rest were polymicrobial. 96.5 % were gram negative while 3.5% were gram positive. All E.coli, Klebsiella spp and S. aureus were found to be MDR followed by Acinetobacter spp (97.2%) and P. aeruginosa (76.2%) About 28.6 % of E. coli, 8.33% of Klebsiella spp and 2.4 % of Pseudomonas aeruginosa were ESBL producers. Acinetobacter spp. was not found to produce ESBL during the study. MBL was present in 17.4% of the gram negative isolates.

Conclusion: We found a high prevalence of MDR strains as a cause of nosocomial LRTI including significant proportions of ESBL and MBL producers. The rate of Acinetobacter spp., including MBL producers, in our hospital setting was alarmingly high which prompts a special attention for the management of such patients as well as urgent need for implementation of infection control strategies.