Identification of Bacterial Species Isolated from the Legs of Chrysomya Screw Flies Using the VITEK 2 System

Abstract

This study deals with the identification and diagnosis of bacteria carried on the legs of screw flies of the genus Chrysomya using the VITEK 2 technique, due to its medical and veterinary importance as a mechanical vector for pathogens. The study was conducted in the field in agricultural areas (orchards and barns) in Diyala Governorate. Samples were collected from three species: Chrysomya megacephala, C. albiceps, and C. putoria. Fermented food traps, which have proven highly effective in attracting flies, were used. A total of 300 flies were collected, with 100 flies from each species. Bacteria were isolated from the flies’ legs after dissection and suspension of the samples in saline solution, and then cultured on different culture media, followed by identification using the VITEK 2 system, which is based on precise biochemical analysis. The results show the presence of three main groups of bacteria: Proteus spp., Pseudomonas aeruginosa, and Staphylococcus aureus. Out of 104 bacterial isolates, Proteus spp. had the highest prevalence (43.27%), followed by Pseudomonas aeruginosa (32.69%) and finally Staphylococcus aureus (24.04%). Regarding their capacity to act as bacterial reservoirs, C. megacephala had the highest capacity compared with other species studied; no statistically significant differences emerged between the various fly species concerning their ability to transmit bacteria. Therefore, the study provides confirmation that screw-flies can be potent vectors for pathogenic bacteria, especially in agricultural settings, thus making them important contributors to disease transmission and indicating the need for monitoring these insects in order to reduce public health hazards