Molecular identification of types TEM, SHV and CTX extended-spectrum-beta-lactamase of escherichia coil, edwardsiell and erwinia spp. Isolated from feces of carriers

Abstract

Aim: Healthy ESBL carrier patients are the major challenge in control of infections produced by members of Enterobacteriaceae. The aims of the present study were to investigate the isolation of TEM, SHV, and CTX type ES beta Ls producing E. coli, Edwardsiella, and Erwinia spp. from feces of carriers.Material and Method: Two hundred fresh stool samples collected from non-hospitalized and hospitalized patients were cultured on MacConkey agar supplemented with 2 mg/L cefotaxime. After 24 hr. Incubation at 37 degrees C the E. coli, Erwinia and Edwardsiella spp were identified by routine biochemical tests. Combined tests were carried out to select ESBLs producing bacteria and susceptibility of isolates was determined by disc diffusion method. Multiplex-PCR was used to identify TEM, SHV and CTX type ES beta Ls producing isolates. Results: Of the 34.5% bacteria resistant to cefotaxime, 81.63% and 55% ESBL producing organisms were recovered from inpatients and outpatients respectively. E coli was the predominant ESBL-producing organism; One Erwinia and three Edwardsiella producing ESBL were detected. Overall, carbapenems including imipenem and meropenem and amikacin were the antibiotics most active against the ESBL-producing organisms. The overall prevalence of these ESBL genes was 73.92%, including the bIaTEM and blaSHV genes alone in 27.45% and 5.88% respectively; blaCTXM were not distinguished alone in any of the isolates. Discussion: More than one ESBL was produced by most isolates carried by patients and Carbapenems, imipenem and meropenem continue to show good in vitro activity against the isolates. Patients can act as a source of ESBL producing bacteria in hospitals.