Detection of New Delhi metallo-β-lactamase-1 (NDM-1) among Klebsiella pneumoniae strains isolated from hospitalized patients in Iran

The global spread of New Delhi metallo-β-lactamase (NDM) is of significant public health concern. The aims of this study were the phenotypic detection of β-lactamases and molecular characterization of NDM in Klebsiella pneumoniae isolates at Tehran, Iran. From March 2014 to February 2017, 120 K. pneumoniae isolates were collected from hospitalized patients admitted to Tehran Hospitals, Tehran, Iran. Antibiotic susceptibility tests were accomplished using Kirby-Bauer disc diffusion and Broth Microdilution methods, according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Detection of metallo-β-lactamase (MBL) activity was performed using the Combined Disc Diffusion Test (CDDT) and carbapenemase production was screened using the Modified Hodge Test (MHT). NDM gene was detected by PCR and Sequencing methods. The resistance of K. pneumoniae isolates to tested antibiotics was 82(68.335%) to cefotaxime, 74(61.66%) to ceftazidime, 12(10%) to ertapenem, 12(10%) to doripenem, 12(10%) to meropenem, 12(10%) to imipenem, 48(40%) to gentamicin, 35(29.1%) to amikacin, 90(75%) to ciprofloxacin, 112(93.4%) to cefpodoxime, 120(100%) to ampicillin, 10(8.3%) to fosfomycin, 90(75%) to cotrimoxazole, 51(42.5%) to levofloxacin and 6(4.9%) to colistin. Of the 120 strains, 92(76.6%) were identified as ESBL-producers. Of 12, five were MBL-producing strain and 2 of them were detected as K. pneumoniae, carrying NDM-1 gene. The coexistence of NDM-1 with other antibiotic resistance genes is also of concern because of limited treatment options. Therefore, it is extremely important to think reasonably about infection control in hospital settings.

کلیدواژه ها:

Klebsiella pneumoniae ، Antibiotic resistance ، carbapenemase ، NDM-1