The bacterial contaminants of cockroaches were identified by both cultural and molecular techniques following standard recommended procedures. Results obtained depicts enhanced accuracy of molecular technique over the cultural method as only 249 (69%) of the total isolates were correctly identified by the cultural method to represent a total of 114 (31%) discrepant species while 100% correct identification was observed with the molecular technique. The most predominant of these bacterial isolates from both the external surfaces and the gut environment was Escherichia coli 43 (20.8%) and 24 (15.5%) respectively. The Gram positive organisms isolated were Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis, and Enterococcus faecalis with a prevalence rate of 8 (3.8%), 14 (6.7%), 8 (3.8%) and 9 (4.3%) from external surfaces and 2 (1.3%), 6 (3.9%), 2 (1.3%) and 7 (4.5%) from gut environment respectively. In all, Gram negative bacteria were more represented in both external surfaces and gut environment than their Gram positive counterpart. The least isolated organisms in the external surfaces were Serratia marscencens and Citrobacter werkmanii with a distribution rate of 3(1.4%) while Citrobacter freundii 2(1.3%) was the least isolated organism from cockroach gut environment. This study therefore showed that cockroaches are ubiquitous contaminants of different bacterial species.
Keywords: Bacterial contaminants, Cockroaches (Periplaneta americana), cultural technique and molecular technique