First prevalence of metallo beta-lactamases producing Enterobacteriacea in Iranian cancer patients

Abstract

Background. Hospital-associated infections, recently renamed Healthcare-associated infections, are among the most common life-threatening complications of hospitalized patients, especially the immunocompmmised patients. Regarding the significant role of Enterobacteriaceae in nosocomial infections and also the increasing trends of carbapenem-resistant strains, the present study aimed to evaluate the antibiotic resistance pattern and the occurrence of metallo-beta-lactcunases (MBLs) in Enterobacteriaceae strains from Iranian cancer patients. Methods. This hospital-based cross-sectional study was conducted in teaching hospitals of two cities in the central parts of Iran during the 6 months period from December 2015 to May 2016. The Enterobacteriaceae isolates were obtained from different clinical specimens and were identified using standard microbiological methods. Antimicrobial susceptibility pattern for the bacterial isolates was determined using the disk diffusion method. The presence of antibiotic resistance genes was determined by PCR method. Results. The distribution of Enterobacteriaceae isolates were 74 (71.8) E. coli, 23 (22.3) Klebsiella spp., 3 (2.9) Pmteus spp., 2 (1.9) Salmonella spp., and 1 (1) Shigella spp. The results of antibiotic susceptibility revealed that all of the isolates were multiple-drug resistant (MDR) and 60 of them were (excluded Salmonella and Shigella) carbapenem-resistant. Of all the carbapenem-resistant isolates, 31.7 were MBL-positive. Meanwhile, fosfomycin and minocycline were the most effective antibiotics against MBL-positive bacteria. Moreover; none of the investigated carbapenemases genes were found in MBL-positive isolates. Conclusion. This study highlights the importance of MBLs producing Enterobacteriaceae in causing nosocomial infections in cancer patients. However, carbapenem resistance was not associated with the presence of MBL genes such as IMP, VIM, and SPM.