Plasmid-Mediated Resistance Genes among Ciprofloxacin-Resistant Enterobacteriaceae Isolates in Neonatal and Pediatric Intensive Care Units

Abstract

Ciprofloxacin resistant Enterobacteriaceae due to plasmid-mediated quinolone resistance genes (PMQR) is a rising problem worldwide. Objectives: The aim of this study was to determine the prevalence of ciprofloxacin resistant Enterobacteriaceae isolates in neonatal and pediatric intensive care units (NICUs and PICUs) through the detection of qnrA, qnrB, and qnrS in clinical isolates. Methods: A total of 329 Enterobacteriaceae isolates were collected from patients attending Misr children hospital. Identification was performed by biochemical reactions, whereas antimicrobial susceptibility testing was done by disk diffusion test. Detection of minimum inhibitory concentration (MIC) of ciprofloxacin was done using E-test method. Multiplex polymerase chain reaction (PCR) was performed for the detection for qnrA, qnrB and qnrS genes simultaneously. Results: The prevalence of ciprofloxacin resistance among Enterobacteriaceae isolates was 15.2%. Klebsiella pneumoniae was the main pathogen isolated from both ICUs, but significantly higher in NICU than PICU (88% and 60%) respectively. This was followed by Escherichia coli and Enterobacter cloacae with higher isolation rates in PICU (24% and 16%) than in NICU (4% and 8%). The qnr genes among all ciprofloxacin resistant Enterobacteriaceae isolates were present at 68%. Among qnr -positive isolates; qnrS and qnrB were detected at 82.4% and 11.8% respectively. In conclusion: The high prevalence of qnr genes detected in Enterobacteriaceae from neonatal and pediatric patients is of serious concern, as ciprofloxacin, although with limited indications in these age groups, it is usually used in life-threatening infections in which they may represent the only effective antibiotic. In addition, this finding highlights the possibility of horizontal transmission of these genes to other pathogenic bacteria.