Cockroaches [Periplaneta americana (L.), Dictyoptera; Blattidae] as Carriers of Bacterial Pathogens, Khorramshahr County, Iran

Background: American cockroaches are found in association with human dwellings and hospitals. They have a worldwide distribution. These domestic pests affect human health in several ways. Their habits make them ideal mechanical carriers of different pathogenic microorganisms. Numerous bacteria of medical importance have been isolated from cockroaches. Objectives: The objective of this research was to determine the role of American cockroaches as carriers of pathogenic bacteria. This was accomplished through the isolation and identification of these microorganisms from the external surfaces of cockroaches captured in Health and Medical Services Centers and their surroundings. Materials and Methods: Seventy-three cockroaches were caught in Health and Medical Services Centers in Khorramshahr County, southwestern Iran, in 2006. The fluid used to wash the external surfaces of cockroaches was cultured to isolate and identify bacterial pathogens. Results: Pathogenic bacteria were isolated from the external surfaces of 100% of the American cockroaches examined. The following bacterial pathogens were recovered from their body surface:Klebsiella (47.9%), Pseudomonas (37%), Escherichia coli (30.1%), Staphylococcus (24.6%), Enterobacter (19.2%), Streptococcus (15.1%), Serratia (8.2%), Bacillus (4.1%), and Proteus (2.7%). Conclusions: The bacterial pathogenic flora isolated from this cockroach species indicate that domestic pests could pose a health problem to humans. Thus, we must control cockroaches, particularly in indoors, sewage and solid wastes.