%0 Journal Article
%T Carbapenem Resistance among Enterobacter Species in a Tertiary Care Hospital in Central India
%A Atul Khajuria
%A Ashok Kumar Praharaj
%A Mahadevan Kumar
%A Naveen Grover
%J Chemotherapy Research and Practice
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/972646
%X Objective. To detect genes encoding carbapenem resistance among Enterobacter species in a tertiary care hospital in central India. Methods. Bacterial identification of Enterobacter spp. isolates from various clinical specimens in patients admitted to intensive care units was performed by routine conventional microbial culture and biochemical tests using standard recommended techniques. Antibiotic sensitivity test was performed by standard Kirby Bauer disc diffusion technique. PCR amplification and automated sequencing was carried out. Transfer of resistance genes was determined by conjugation. Results. A total of 70/130 (53.84%) isolates of Enterobacter spp. were found to exhibit reduced susceptibility to imipenem (diameter of zones of inhibition ¡Ü13£¿mm) by disc diffusion method. Among 70 isolates tested, 48 (68.57%) isolates showed MIC values for imipenem and meropenem ranging from 32 to 64£¿mg/L as per CLSI breakpoints. All of these 70 isolates were found susceptible to colistin in vitro as per MIC breakpoints (<0.5£¿mg/L). PCR carried out on these 48 MBL (IP/IPI) -test positive isolates (12 Enterobacter aerogenes, 31 Enterobacter cloacae, and 05 Enterobacter cloacae complex) was validated by sequencing for beta-lactam resistance genes and result was interpreted accordingly. Conclusion. The study showed MBL production as an important mechanism in carbapenem resistance in Enterobacter spp. and interspecies transfer of these genes through plasmids suggesting early detection by molecular methods. 1. Introduction Beta-lactams are one of the most frequently used classes of antimicrobials in hospital settings, crucial for the treatment of infections caused by Gram-negative bacteria. Enterobacter spp. are common pathogens of Enterobacteriaceae family responsible for nosocomial infections, especially blood stream infections in intensive care units. Enterobacter may produce severe diseases including those of abdomen, lower respiratory tract, urinary tract, meningeal, eye, bone, and surgical site infections [1]. As per National Nosocomial Infection Surveillance System, more than one-third of the Enterobacter spp. are resistant to extended-spectrum cephalosporins in intensive care units [2]. However, of late due to the presence of extended-spectrum beta-lactamase (ESBL) and AmpC enzymes in Enterobacter spp., Carbapenems have become the drug of choice to treat such infections [3]. There has been an increase in incidence of multidrug resistance in these organisms due to dissemination of resistance determinant genes mediated by transposons, plasmids, and gene
%U http://www.hindawi.com/journals/cherp/2014/972646/