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 beginning
of October 2016 to April 2017 to isolate and diagnose the bacteria on the
outer surface of the domestic fly (Musca domestica) and to determine the
sensitivity of bacterial isolates against antibiotics using different
agricultural mediums. Insects were collected from three sites in the Tikrit
city which are: vegetable market, butchers market and sheep sheds. 50
samples were collected from each site. Bacterial isolates obtained from
the external surface of insects were subjected to morphological and
biochemical 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 the
bacterial species with an isolation rate of 23.5%, followed by Salmonella
typhi 32 isolates by 20.9% , and Proteus mirabilis 31 isolates by 20.3% .
Staphylococcus aureus has 25 isolations by 16.3%. Klebsiella pneumonia
has 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% , Then
Hafina spp. Has 3 isolations by 1.9% , Serratia marcescens has only two
isolates by 1.3% .
The results showed that the highest contamination rate was in the
vegetable market which is 92%, then the sheep sheds is 88%, and finally
Butchers market is 86%.
The Gram-negative bacterial isolates were tested for sensitivity to 8 types
of antibiotics, E.coli showed the highest resistance to both Erythromycin
and Ceftriaxon by 77.8% , while S.typhi showed resistance to Amikacin
and Ceftriaxon by 53.1%, P.mirabilis was resistant to Tetracyclin by
64.5%, 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 to
Chloramphenicol, Finally, Ser.marcescens were 100% resistant to
Erythromycin.
The sensitivity of Staph.aureus bacteria was tested against 5 types of
antibiotics with the highest resistance to Vancomycin by 80% .