Carbapenem Resistance among Enterobacter Species in a Tertiary Care Hospital in Central India

Abstract

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 ≤13 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) E-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.

Isolation of Enterobacter aerogenes carrying blaTEM‐1 and blaKPC‐3 genes recovered from a hospital Intensive Care Unit

“…Among the different carbapenemase‐producing Enterobacteriaceae, the most common species after K. pneumoniae is E. coli , while various others species have been isolated sporadically both from infected and colonized patients . A recent study in India evidenced that Enterobacteriaceae infection in health care settings that cause often outbreak arise endogenously from a previous colonized gastrointestinal tract in an infective individual.…”

Prevalence and mechanisms of carbapenem resistance among Klebsiella aerogenes in a tertiary hospital in China

“…Since the rst report of imipenem-resistant K. aerogenes in 1990 [6], the reports about carbapenem-resistant K. aerogenes (CRKA) have increased gradually. The prevalence of CRKA was 4.0% in France [7] and 12.5% in the USA [8], while it has reached 21% in a Chinese hospital in Shanghai [9] and 26.7% in a tertiary care hospital in Central India [10]. The mechanisms of carbapenem resistance of K. aerogenes usually include production of carbapenemases, overproduction of β-lactamases, e ux pumps, porin de ciency, and a change in penicillin-binding proteins [11,12].…”

A Snapshot of Co-Resistance to Carbapenems and Tigecycline in Clinical Isolates ofEnterobacter cloacae

“…1 Furthermore, the organisms can become resistant to thirdgeneration cephalosporins through the acquisition of exogenous AmpC b-lactamase genes, such as bla DHA and bla CMY , and/or extended-spectrum b-lactamase (ESBL) genes, such as bla SHV , bla TEM , and bla CTX-M , often transferred through plasmids. [3][4][5] In addition, the bacterium can acquire carbapenemase genes, such as bla GIM , 6 bla IMP , 7-9 bla VIM , [9][10][11] bla NDM , 11,12 bla OXA , 13 and bla KPC , 14,15 and become resistant to carbapenems. Decreased expression of outer membrane proteins and overexpression of efflux pumps may also occur and result in resistance to multiple drugs, including carbapenems and tigecycline.…”