Identification of Extended-Spectrum Beta-Lactamase (ESBLs) and Colistin Resistance Genes in Escherichia coli Isolated from Blattella germanica (German cockroaches) by Dot Blot Assay in Hamadan Hospitals, Iran – 2018

Multidrug-resistant (MDR) Escherichia coli is one of the main causes of nosocomial infections especially in intensive care units (ICU). Battelle germanica are widespread. The presence of these insects in the hospital can carry a risk of various infections in addition to their pathogenicity. This study aimed to identify extended-spectrum beta-lactamase (ESBLs) and colistin resistance genes in E. coli isolated from Blattella germanica (German cockroaches) by a dot blot assay in Hamadan hospitals in west Iran. B. germanica were trapped and identified using reliable taxonomic keys by an expert in the Department of Entomology, Hamadan University of Medical Sciences, Iran. E. coli isolates were identified and confirmed by conventional microbiological and biochemical tests. Then, the antibiotic resistance pattern was determined. A dot blot assay was used to identify resistance genes in E. coli isolated from B. germanica. Thirty-one E. coli were isolated from 109 B. germanica. Determination of the pattern of antibiotic resistance showed that ampicillin and colistin had the highest and lowest resistance frequencies, respectively. Dot blot assay was employed to determine the extended-spectrum beta-lactamase resistance genes, where 8 isolates had the bla CTX gene (29.03%) and one isolate had bla SHV genes (3.2%). The results indicated that the B. germanica are an important factor for the transmission of Enterobacterales as well as multidrug resistant (MDR) strains. Therefore, effective preventive and control measures are needed to reduce vector-borne diseases.