Abstract

Cockroaches are cosmopolitan and are found in warm snug places. They are active at night and like to live in humid cracks, behind appliances, cabinets and drawers. They carry microbes on their external body surfaces as they often live in unsanitary places and are thus dangerous to human. This study was carried out in Quetta city. 50 samples of cockroaches were collected from washroom, kitchen and gardens from different areas of Quetta city. The collected cockroaches were brought to the laboratory for further investigation. The cockroaches were inoculated in brain heart infusion (BHI) broth and were incubated at 37°C for 24 h. The subcultures were made on Mac Conkey, SS and EMB agar for the isolation and purification of microorganisms. Biochemical tests that were catalase, simon citrate, methyl red and Voges-Proskauer (MR-VP) and motility tests were applied and the results show the presence of 82% Salmonella and 64% Escherichia coli on the external surfaces of cockroaches. It is deduced from the study that cockroaches are vital carriers of infectious pathogens; therefore, their control is necessary to minimize the spread of such infectious diseases.

Key words: Cockroaches, broth, agar, biochemical tests, Salmonella, Escherichia coli, pathogens.