Comparison of Contamination of Bacteria Isolated from the External and Internal Surfaces of Cockroaches Collected from Several Hospitals in Hamadan City

Cockroaches are one of the most important carriers of disease that involved human health, they can carry a great variety of pathogenic bacterial and then freely moved in the hospital environment. The presence of cockroaches in the hospital is a potential problem to the healthcare system. This study was aimed to determine the type of cockroaches and bacterial species in some hospitals of Hamadan University of Medical Sciences, Iran, 2017. The present cross-sectional study was conducted in Fatemieh and Sina hospitals, Hamadan. 179 cockroaches were trapped at night and early morning from different parts of hospitals in a sterile condition. The insects were transported to the laboratory for analysis. To isolation and identification of bacteria, suspension prepared from the external surface and internal digestive tract of cockroaches. Bacteria species identification was performed by using selective media and specific diagnostic tests. Statistical analysis was done by using SPSS V.20. In this study, of the 179 cockroaches caught, 117 cockroaches were American (65.36%) and 62 German cockroaches (34.64%). Bacterial contamination was diagnosed in 173 (99.42%) cockroaches. Our results revealed the maximum contamination was observed in American cockroach (648 (77.4%) colony) and minimum contamination was observed the German cockroach (189 (22.6%) colony). The most predominant species of bacteria isolated from American and German cockroaches were Escherichia coli  223(26.6%), and the lowest found was Staphylococcus aureus 4(0.5%). Bacterial contamination of cockroaches in the hospital environment is an important concern in Hamadan health care systems. Moreover, antibiotic resistance observed in separated bacteria can enhance the pathogenicity of bacteria. So, we can conclude that cockroaches can contribute to the dissemination and spread of bacterial infection. Results suggest that elimination of cockroaches from human environments could reduce the bacterial infections.