Background: Considering the importance of cockroaches in mechanical and biological transmission of pathogenic bacteria in hospitals, the present study aimed to study the bacterial and fungal agents of German cockroaches (Blattella germanica L.) in Mashhad Imam-Reza hospital.

Materials and Methods: This descriptive study was conducted on 100 German cockroaches sampled from Mashhad Imam-Reza hospital during Autumn 2009 and Spring 2010. After dissection of the digestive tract under sterile condition, the extractions were incubated separately in the EMB, Blood Agar and Saburo Dextrose Agar media. Bacterial and fungal flora of the cockroaches' digestive system was identified in terms of the number and percentage of the isolates.

Results: All cockroaches collected in both seasons were contaminated with bacteria. The most prevalent bacterium was Enterococcus spp. with the frequency of 27.85 and 20.51% in autumn and spring, respectively. Among the 50 cockroaches collected from the hospital in each of the Autumn and Spring seasons, 8 (16%) and 7 (14%) cockroaches showed the fungal contamination, respectively. The most prevalent fungal isolate in autumn was Penicillium spp. with the frequency of 50% and in spring Mucor spp. with the frequency of 57.14%.

Conclusion: High population density of German cockroaches in Mashhad Imam-Reza hospital is worrisome. Considering the great diversity and frequency of bacterial and fungal flora in digestive tract of the cockroaches and to reduce the risk of transmission of pathogenic agents, suitable control measures should be applied to manage the population of cockroaches in hospital settings.