Survey of various carbapenem-resistant mechanisms of and isolated from clinical samples in Iran.

OBJECTIVES

and resist antibiotics by different intrinsic and acquired mechanisms. This study aims to define various carbapenem-resistant mechanisms of isolated and from nine different provinces of Iran.

MATERIALS AND METHODS

In this cross-sectional study, all carbapenem-resistant and samples from nine provinces of Iran on a one-year time horizon were gathered. Modified Hedge Test (MHT) and Carba NP-Test were applied to the identification of producing-carbapenemase strains. The most important carbapenemase genes recognized by PCR and gene overexpression of the efflux pump were surveyed by efflux pump inhibitors (EPIs) and confirmed by Real-Time PCR.

RESULTS

Twenty-one percent and 43.5% of and isolates were resistant to carbapenem, respectively. MHT and Carba-NP tests identified 21% and 11% carbapenemase-producing strains in these Gram-negative bacteria, respectively. NDM-1 was the most prevalently detected carbapenemase in ; OXA-51 and OXA-23 were the most significant genes in . EPIs identified active efflux pumps in 20% and 28% of and , respectively. Real-time PCR confirmed gene overexpression of efflux pumps in 54% and 30% of positive EPIs in and , respectively.

CONCLUSION

and may become multi-drug-resistant (MDR) and Extensively Drug-Resistant (XDR) strains and cause a high rate of mortality and morbidity. Thus, it is of necessity to prohibit the spread of antibiotic-resistant strains in hospitals.