New Delhi metallo-β-lactamase-1-producing isolates in hospitalized patients in Kashan, Iran.

BACKGROUND AND OBJECTIVES

New Delhi metallo-ß-lactamase (NDM) is a newly emerging metallo-ß-lactamases, which can destroy all β-lactams including carbapenems. Therefore, this study aimed at evaluating New Delhi metallo-ß-lactamase-1-production in clinical isolates of in Kashan, Iran.

MATERIALS AND METHODS

In a cross-sectional study, 181 isolates were collected from clinical samples of patients, who referred to Shahid Beheshi hospital in Kashan during November 2013 and October 2014. Antimicrobial susceptibility patterns were determined using disk diffusion method, according to CLSI guidelines. Metallo-ß-lactamase (MBL) production was identified among imipenem-resistant isolates using imipenem-EDTA double disk synergy test (EDTA-IMP DDST). PCR method and sequencing were used to detect integron Class 1 and gene. Statistical analyses were performed using SPSS software Version 16.

RESULTS

Of the 181 isolates, 36 (19.9 %) were imipenem-resistant strains. A total of 28 out of 36 (77.7%) imipenem-resistant isolates were identified as MBL producer strains. Also, 150 (82.9%) isolates carried gene, and 20 (11.1%) isolates harbored gene.

CONCLUSION

Our study revealed a high frequency of MBL production and the presence of among strains, especially among hospitalized patients, which is alarming. Moreover, the presence of Class 1 integrons in all multi-drug resistant isolates highlights the risk of rapid spread of the resistance genes, especially in clinical settings.