New Delhi metallo-β-lactamase - type carbapenemases producing Escherichia coli isolates from hospitalized patients: A pilot study

Abstract

Background & objectives:Resistances to carbapenem group of antimicrobials among Escherichia coli due to production of carbapenemases, especially the New Delhi metallo-β-lactamase (NDM) types, pose serious challenges in the treatment of infections in healthcare settings. This study was undertaken to detect NDM producing E. coli isolates from hospitalized patients with urinary tract infection (UTI).Methods:A total of 30 non-repetitive isolates of E. coli from hospitalized patients with clinical suspicion of UTI were subjected to antimicrobial susceptibility testing. Screening for the production of extended-spectrum β-lactamases (ESBL) was carried out by minimum inhibitory concentration (MIC) test strip ESBL followed by phenotypic confirmation by double-disc synergy test. Phenotypic confirmation of carbapenemase production was carried out by MIC test strip metallo-β-lactamases. Molecular identification of the blaNDM gene was carried out by polymerase chain reaction (PCR) and sequencing of the amplified fragment.Results:Seventeen of the 30 isolates were detected as ESBL producers, of which three were found to be carbapenemase producers. NDM genes were detected by PCR followed by gene sequencing in all three isolates positive for ESBL as well as carbapenemase. The amino acid sequence of the three isolates showed complete identity to the reference sequences of NDM-1, NDM-4 and NDM-8, respectively.Interpretation & conclusions:Our study showed the circulation of NDM variants among the clinical isolates of E. coli that were producers of ESBL as well as carbapenemase.

Detection of Klebsiella pneumoniae Carbapenemase (KPC) Producing Enterobacteriaceae Isolates from Various Clinical Samples in a Rural Health Setup

“…However, various studies conducted in India before 2006 failed to show any evidence of resistance for E. coli and K. pneumoniae to carbapenems 10 , Indian subcontinent serves as a reservoir for all 3 types of carbapenemases: KPC, OXA-181 and NDM 8 .…”

Analysis of antibiotic resistance genetic conditioning of Enterobacteriaceae NDM-1 family members and the related epidemiological threat in Poland

“…Subsequent variants of this enzyme, marked sequentially from 2 to 17, are very rare. NDM-3, -4, -5, -6, -7, -8, -11, -12, -13, -15, and -17 were detected in E. coli, while NDM-9, -10, and -16 were detected in K. pneumoniae [29,40]. Importantly, NDM metallo-b-lactamases (especially NDM-1) are sometimes present in individual representatives of Vibrionaceae and other non-Enterobacteriaceae species [41].…”

“…The bla NDM gene is responsible for coding the NDM-1 enzyme [29]. It can be located both on the bacterial chromosome and on plasmids [27].…”

“…It can be located both on the bacterial chromosome and on plasmids [27]. The second of these locations promotes horizontal gene transfer and the spread between bacteria of the gene encoding the carbapenemase [27,29]. The bla NDM gene has been located on plasmid types such as IncF [30,31], IncA/C [30,32], or IncL/M [33].…”

Increasing prevalence of Escherichia coli and Klebsiella pneumoniae producing CTX-M-type extended-spectrum beta-lactamase, carbapenemase, and NDM-1 in patients from a rural community with community acquired infections: A 3-year study

“…Commercially available MIC test strip MBL (Liofilchem, www.liofilchem.net) was used to carry out presumptive screening of MBL-producing strains. [ 9 15 ] The MBL strip had an imipenem (IMI) gradient at one end (4–256 μg/mL) and gradient of imipenem (1–64 μg/mL) plus a constant level of EDTA (4 μg/mL) at another end (IMD). The MBL production was considered positive when a strain showed MIC ratio of IMI/IMP+EDTA as ≥8.…”