الهام سلطان زاده

In this study, the bacteria of the food cold storages of three big hospitals in Tehran were evaluated. Sampling of food refrigerators from different departments of 3 hospitals with more than 400 beds was done once a week during 10 consecutive months from June to March 2018. After determining the identity of the isolates with differential tests, the pattern of antibiotic resistance was determined and the presence of antibiotic resistance genes of resistant strains was checked by molecular PCR method. A total of 236 positive samples were isolated from refrigerators and 42 positive samples from cold rooms of three hospitals. The most positive samples were obtained from devices with inappropriate appearance, temperature above 8°C, and the floors of refrigerators. Most of the isolates belonged to the bacterial group Enterobacter (68.8%), Staph (11.9%) and Enterococcus (10.6%). 2 cases of salmonella spp and 1 case of L. monocytogenous were isolated from cold storages. Refrigerated samples were sensitive to all antibiotics used in this study. In refrigerator isolates, the highest resistance was related to ESBL (9.7%), VRE (5.3%), MRSE (0.4%) and MRSA (0.4%), respectively. In the extensive investigation of resistance genes, blaOXA-48, blaCTX and blaTEM genes were found in 10% of Enterobacter group isolates. blaOXA-51 gene was found in all non-Enterobacter resistant strains and mecA and vanA genes were found in staph and enterococcus resistant isolates. Bacterial contamination of hospital refrigerators is a warning about the possibility of transmission of contamination, outbreak of disease, failure in treatment, exacerbation of disease complications and risk of transfer of resistant genes from resistant strains to sensitive strains.