Isolation and Identification of some Species of Bacterial Pathogens from Musca Domestic and Test their Susceptibility Againts Antibiotics

Abstract

The current study was conducted during the period from the beginningof October 2016 to April 2017 to isolate and diagnose the bacteria on theouter surface of the domestic fly (Musca domestica) and to determine thesensitivity of bacterial isolates against antibiotics using differentagricultural mediums. Insects were collected from three sites in the Tikritcity which are: vegetable market, butchers market and sheep sheds. 50samples were collected from each site. Bacterial isolates obtained fromthe external surface of insects were subjected to morphological andbiochemical tests and API 20 E system was used for diagnosis.153 isolations were obtained belonging to 9 bacterial species .Escherichia coli reached 36 isolations that prevailed the rest of thebacterial species with an isolation rate of 23.5%, followed by Salmonellatyphi 32 isolates by 20.9% , and Proteus mirabilis 31 isolates by 20.3% .Staphylococcus aureus has 25 isolations by 16.3%. Klebsiella pneumoniahas 11 isolations by 7.2% , and Shigella spp has 7 isolates by 4.6%,followed by Citrobacter freundii which has 6 isolates by 3.9% , ThenHafina spp. Has 3 isolations by 1.9% , Serratia marcescens has only twoisolates by 1.3% .The results showed that the highest contamination rate was in thevegetable market which is 92%, then the sheep sheds is 88%, and finallyButchers market is 86%.The Gram-negative bacterial isolates were tested for sensitivity to 8 typesof antibiotics, E.coli showed the highest resistance to both Erythromycinand Ceftriaxon by 77.8% , while S.typhi showed resistance to Amikacinand Ceftriaxon by 53.1%, P.mirabilis was resistant to Tetracyclin by64.5%, Shigella spp. was resistant to Ceftriaxon by 57.14%,K.Pneumonia bacteria were resistant to Erythromycin by 72.7% ,C.freundii showed resistance to the antibiotic Trimethoprim +Sulfamethoxazol and 100%, Hafnia was 33.33% resistant toChloramphenicol, Finally, Ser.marcescens were 100% resistant toErythromycin.The sensitivity of Staph.aureus bacteria was tested against 5 types ofantibiotics with the highest resistance to Vancomycin by 80% .