RT Journal Article SR Electronic(1) A1 Mohapatra, Debi Prasad A1 Singh, Santosh Kumar A1 Sahoo, Minu A1 Patole, Shashank A1 Mishra, Mitali A1 Debata, Nagen Kumar A1 Mohapatra, HarapriyaYR 2018 T1 Retrospective study on clonal relationship of multidrug-resistant Klebsiella spp. indicates closed circulation and initiation of clonal divergence JF Journal of Medical Microbiology, VO 67 IS 5 SP 611 OP 619 DO https://doi.org/10.1099/jmm.0.000715 PB Microbiology Society, SN 1473-5644, AB Purpose. Antibiotic resistance patterns often exhibit geographical variations. Periodic analyses of resistance spectra and phylogenetic trends are important guides for facilitating judicious use of therapeutic interventions. The present study retrospectively analysed the infection trends, resistance patterns, and clonal relationships between isolates of Klebsiella spp. from a tertiary care hospital. Methodology. Bacterial isolates were collected from January 2013 to June 2014 and their resistance profiles were identified using an automated bacterial identification system. A phylogenetic tree was constructed using housekeeping genes with Molecular Evolutionary Genetic Analysis software. The d N/d S ratio was determined by the Synonymous Non-synonymous Analysis Program while polymorphic sites, and the difference per site was calculated using DNA Sequence Polymorphism software. Statistical Package for Social Science software was used to perform all statistical analyses. Key findings. The results of this study indicated the prevalence of community-acquired urinary tract and lower respiratory tract infections caused by Klebsiella spp. among geriatric patients. The occurrence of new allelic profiles, a low d N/d S ratio and the lack of strong evolutionary descent between isolates indicated that mutations play a major role in the evolution of the organism. Conclusion. The findings of this study highlight the consequences of antimicrobial agents exerting a silent and strong selective force on the evolution of Klebsiella spp. The expansion of such analyses is of great importance for addressing rapidly emerging antibiotic-resistant opportunistic pathogens., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000715