Seasonal Variation in Klebsiella pneumoniae Blood Stream Infection: A Five Year Study

Introduction: Klebsiella pneumoniae is a ubiquitous environmental organism and a common cause of serious gram-negative infections in humans. This study was conducted to examine the association between seasonal variation and the incidence rate of Klebsiella pneumoniae blood stream infection. Material and methods: The retrospective study was conducted in the Department of Microbiology, JN Medical College AMU Aligarh for a period of 5 years from January 2011 to December 2015. Samples were received for blood culture in brain heart infusion broth. Cultures showing growth of Klebsiella pneumoniae were identified using standard biochemical procedures. Antimicrobial susceptibility testing was done on Mueller Hinton’s agar by Kirby Bauer Disc diffusion method as per the CLSI guidelines. Detection of ESBL, AmpC and MBL production was done. Results: 495 (30.0%) isolates were found to be positive for Klebsiella pnuemoniae during the five year study period. Prevalence of Klebsiella pneumoniae isolates in blood stream infection for the warmest four months (July- September) was found to be 61.8% as compared to 38.2% in the remaining year (January-June and October- December). Maximum number of Klebsiella pneumoniae were isolated the month of August 86 (17.3%) followed by July 75 (15.1%) while minimum isolates were found in the month of February 14 (2.8%) and January 19(3.8%). ESBL producing isolates were 44 (8.8%) and 318 (64.20%) isolates were AmpC producers. 36 (7.2%) isolates were found to be MBL producer. Conclusion: Our study suggests that K. pneumoniae is an important pathogen in hospitals worldwide and that rates of K. pneumoniae blood stream infection vary seasonally.