Response of Microbes Associated with Internal and External Surfaces of Blattella germanica towards Hydrophobicity and Autoaggregation

Abstract

German cockroaches (Blattella germanica) are distributed worldwide. Pathogens present on cockroach have always raised safety concerns. Present study aimed to check the bacterial autoaggregation and hydrophobicity potential. Cockroaches were trapped from house sewerage of Lahore, Pakistan in March 2016 and bacteria were isolated from external as well as internal part of cockroach. For isolation from internal colon part of digestive tract were serially diluted and selected (IM1 and IM3) from bacterial growth on agar plates while isolates from external surfaces of cockroach were selected by surface swabbing (EM4, EM5 and EM6). Morphological and biochemical characterization of isolates showed diverse morphology. The auto aggregation was recorded in all isolates after 4 hours of culture incubation. Results of hydrophobicity assay showed that isolates IM1, IM3, EM5 showed 98.09 %, 80.5 %, 90.33 % affinity towards toluene, respectively. Bacteria commonly associated with common pests, cockroaches showed the tendency to adhere to different biotic and abiotic surfaces. Isolate IM3 showed 35 % auto-aggregation after 4 hours while isolate EM4 showed 47 % aggregation as compared to rest of isolates. Result showed that on the basis of bacterial cell surface hydrophobicity and auto aggregation tendency of cells towards adherence and aggregation on host increases.