Identification of capsular vaiants of Klebsiella pneumoniae clinical isolates and antimicrobial resistance profile in educational hospitals of Tehran

Introduction and Objectives: The capsular polysaccharide is a main virulence factor in Klebsiella pneumoniae and serotypes K1and K2 are the most virulent types in human infections. The aim of this study were to assess the antimicrobial susceptibility and to determine the distribution of serotypes K1, K2 by detecting of wzc and orf10 genes in clinical isolates of K. pneumoniae. Materials and methods: A prospective study was carried with a total of 120 consecutive, non-duplicate isolates of K. pneumoniae recovered from various clinical specimens from patients admitted to educational hospitals of Tehran. Antibiotic susceptibility of isolates was determined using a disk diffusion method. The presence of wzc and orf10 genes was detected by polymerase chain reaction. The data were analyzed by using descriptive statistics and chi-square. Results: Totally, 75 (62.5%) of isolates showed multidrug resistance (MDR) pattern. The highest and lowest rates of resistance were related to amoxicillin 68.2% and ciprofloxacin 91.8%, respectively. Results of the PCR assay showed that 57 (47.5%) isolates related to K1serotype, 12 (10%) to K2 serotype and 51 (42.5%) of isolates were belonged to non K1/ K2 serotypes. no significant association was seen between serotypes K1, K2 and MDR pattern (P< 0.05). Conclusion: The present study indicated considerable rate of serotypes K1, K2 with MDR pattern among clinical isolates of K. pneumoniae collected from Tehran hospitals. Considering the major role of these serotypes with high rates of drug resistance in different clinical infections, using of appropriate infection control measures and treatment strategies are essential to prevent further dissemination of these virulent and resistant isolates in clinical settings.

Keywords:

Klebsiella pneumonia , capsular polysaccharide K1 , capsular polysaccharide K2 , multiple drug resistance