Results: From four identified species,
Blatella germanica were the most common in all of the wards (88.8%) and next was the Periplaneta
Americana (8%). 20 bacteria species isolated from cockroaches' surface and 21 from digestive
organ. Escherichia coli were the most predominant bacteria isolated from external surface (26.5 %)
as well as alimentary tract (30.8%). The frequency of investigated bacteria on cockroaches' body
surface was not significantly different between Periplaneta Americana and Blattella germanica
except for Kllebsiella oxytoca (P