Isolation of bacteria from the digestive tract of Periplaneta americana and Polyphaga aegyptiaca (Blattodea: Blattidae) in Khuzestan Province, Southwestern Iran

Abstract

Cockroaches are one of the most common household pests carrying different microorganisms of medical importance. The aim of this research was to isolate, characterise and do a susceptibility profiling using disk diffusion method of bacteria from the digestive tract of Periplaneta americana and Polyphaga aegyptiaca. A total of 139 cockroaches were collected between May and December 2015, in Khuzestan Province of Iran. Bacterial species were isolated from the digestive tract of both P. americana and P. aegyptiaca. Among the 139 cockroaches collected, 126 (90.6%) were found to harbour one or more species of bacteria in their digestive tract. There was significant difference in the overall positivity rates of P. americana (93.6%) and P. aegyptiaca (61.5%) (p < 0.05). Eighteen species of bacteria were isolated from the two species of cockroaches. Antibiotic resistance was found in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Serratia marcescens and Proteus mirabilis isolated from the cockroaches digestive tract. This is the first study where isolation of bacteria with antibiotic resistance to P. aegyptiaca was observed. The findings of the present study revealed and confirmed that P. americana and P. aegyptiaca are important agents in transmission of bacterial pathogens. Health education on control and prevention methods of cockroaches and their role in transmission of diseases in communities especially the study area Dezful County in Khuzestan province, southwestern Iran is recommended.