Fly maggots (Diptera: Calliphoridae, Muscidae) and associated microorganisms in Gaborone

Abstract

Synathropic species of flies carry pathogenic organisms that result in diseases such as bacillary dysentery, salmonellosis, cholera and diarrhea. Microorganisms associated with fly maggots were isolated and identified in the present study in Gaborone. Fly maggots were collected randomly from four geographical areas of Gaborone i.e. Tlokweng, Ledumang, University of Botswana campus and Maruapula. The external and internal microbes of the fly maggots were isolated and examined microscopically. Determination of aerobic mesophilic and psychrotrophic plate counts were conducted. Tests for yeasts and molds were also done. Biochemical characterization, identification and confirmation of microbial isolates were done using Analytical Profile Index (API 20E) and Vitek II. Colony counts ranged from 1.4x10³ to 8.3x10³ colony forming units (CFU/g). Salmonella spp. was a common isolate in all the geographical areas while Providencia stuartii, Pseudomonas aeruginosa, Pseudomonas fluorescens and Citrobacter braakii were only identified in maggots from Tlokweng. The most common species of flies in Gaborone identified from the maggots were Chrysomyia megacephala and Musca domestica, and few syrphid spp. The microorganism isolated from the maggots of these flies can be given as Salmonella spp., Salmonella arizonae, Klebsiela oxytoca, Enterobacter cloacae, Providencia stuartii, Pseudomonas aeruginosa, Pseudomonas fluorescens and Citrobacter braakii with Salmonella spp. as the dominant species.