Phenotypic and genotypic characteristics of carbapenem-resistant Enterobacteriaceae in a tertiary-level reference hospital in Turkey

Abstract

BackgroundEnterobacteriaceae are among the most common pathogens that are responsible for serious community-acquired, hospital-acquired, and health-care associated infections. The emergence and spread of carbapenem-resistant Enterobacteriaceae (CRE) have become an increasing concern for healthcare services worldwide. Infections caused by these bacteria have been associated with significant morbidity and mortality and treatment options have been limited. The rapid and accurate detection of carbapenem resistance in these bacteria is important for infection control. The aim of this study was to investigate the phenotypic and genotypic features of CRE strains isolated in a tertiary-level reference hospital in Turkey.MethodsA total of 181 CRE strains were included in the study. Antimicrobial susceptibility rates were tested using Vitek 2 system. Modified Hodge test (MHT) was performed using meropenem and ertapenem discs. Metallo-β-lactamase antimicrobial gradient test (E-test MBL strips) were used for evaluation of metallo-β-lactamase production. A multiplex PCR was used for detection of carbapenems resistance genes (IMP, VIM, KPC, NDM-1 and OXA-48).ResultsThe OXA-48 gene was detected in 86 strains, NDM-1 gene in six strains, VIM gene in one strain. IMP and KPC genes were not identified. Three strains produced both OXA-48 and NDM-1 and one strain produced both OXA-48 and VIM. In two patients more than one genus of OXA-48 positive CREs was isolated. Ninety-two of the isolates were multidrug-resistant. One hundred and ten isolates were MHT with meropenem (MEM-MHT) positive and 109 isolates were MHT with ertapenem (ERT-MHT) positive. Nine of the isolates were positive with E-test MBL strips. The sensitivity of MEM-MHT and ERT-MHT for detection of OXA-48 was 70.9 and 70.6 %, respectively. MEM-MHT was found highly discriminative for OXA-48 Escherichia coli (p < 0.001). The sensitivity of E-test MBL for NDM-1 was 66.7 %. A statistically significant correlation was observed between OXA-48 gene and MHT positivity and between NDM-1, VIM gene and E-test MBL positivity (p < 0.001).ConclusionsOXA-48 gene is spreading rapidly to many different species of Enterobacteriaceae in the hospital environment. While OXA-48 is still the most common source of carbapenem resistance in Enterobacteriaceae in our country, NDM-1 is increasingly being isolated from patients without a history of foreign contact.

Occurrence and characterization of carbapenem‐resistant Gram‐negative bacilli: A collaborative study of antibiotic‐resistant bacteria between Indonesia and Japan

“…Other studies have found UTI-causing CRE to be between 1.4-4.2% in the USA, 18 1.2% in Lebanon, 4.05% in Malaysia, <1% in Singapore, 1.2% in Taiwan and 1.17% in Saudi Arabia. 19 The present study showed that 2.4% of 4861 urine specimens and 10.7% of 1082 Gram-negative isolates were CR-GNB, comparable with other countries. Among them, 22 (0.45%) were CP-GNB, or 19% among CR-GNB and 2% of all Gram-negative isolates.…”

“…NDM‐1‐producing Enterobacteriaceae might carry other mechanisms for antibiotic resistance with various β‐lactamases and other types of carbapenemases resistant to other antimicrobials . We found that 18 strains with bla NDM‐1 were susceptible to MINO, TMP/SMX and TGC than P. aeruginosa strains with bla IMP‐7 .…”

“…Baran et al . isolated CRE having co‐producing carbapenemase ( bla NDM ‐ 1 and bla OXA‐48 ) and ESBL . We found that ESBL‐producing strains were still susceptible to CL and TGC.…”

The Efficacy of the MicroScan®Walkaway System in Reporting Carbapenemase-Producing Enterobacteriaceae in Patients with Bacteremia, South Africa

“…Carbapenemaseproducing Enterobacteriaceae (CPE) are capable of hydrolysing Carbapenems and all other β-lactam antibiotics [5][6][7]. Although plasmid-mediated resistance is not the only mechanism of resistance among CRE, it is the most epidemiologically important due to the high efficiency at which Enterobacteriaceae exchange plasmids among each other [7].…”

“…Mechanisms for Carbapenem resistance in Enterobacteriaceae include hyper-production of extended spectrum beta-lactamases (ESBLs), class c-β-lactamases (AmpC), mutations in porins and alterations or up-regulation of efflux pumps [6]. The most common Carbapenemases worldwide include the metallo-β-lactamases New Delhi-metallo-β-lactamase (NDM), Imipinemase β-lactamases (IMP), Verona integron encoded metallo-β-lactamase (VIM), Guiana extended spectrum β-lactamases (GES), and Oxacillinase β-lactamase (OXA-48 types) [8][9][10][11][12][13][14].…”