Prevalence and antimicrobial susceptibility of staphylococcus aureus isolated from cattle, buffalo, sheep and goat`s raws milk in Sohag Governorate, Egypt

Abstract EN

The objective of this study is to determine the prevalence rate of S.

aureus in cow, buffalo, sheep and goat`s raw milk in Sohag Governorate, Egypt by using conventional methods and molecular technique and further characterization of their antimicrobial resistance.

Isolation and identification of S.

aureus were performed for a totally of 340 raw milk samples from cow, buffalo, sheep and goat`s milk randomly selected from dairy farms and shops.

Altogether, S.

aureus was isolated from 136 raw milk samples (40 %) of the 340 milk samples 44(36.

7 %) from fresh cow milk samples 65(46.

4 %) from buffalo milk 12(30 %) from sheep milk and 15(37.

5 %) from goat`s milk samples.

Amplification of genes encoding clumping factor (clfA) and thermonuclease (nuc) gene by Polymerase Chain Reaction was used for the genotypic characterization of isolated S.

aureus strains.

All tested S.

aureus strains yielded a single amplicon with a size of approximately 985 bp by amplification of the (clfA) gene, however, amplification of the ( nuc) gene produced an amplicon of 270 bp in all examined S.

aureus isolates.

The susceptibilities of the isolates were determined for 11 antimicrobial drugs using the disk diffusion assay.

Total of S.

aureus isolates originating from cow’s and buffalo’s milk were more resistant than those of goat and sheep origin.

The resistance pattern of S.

aureus isolates originated from raw milk from cow’s and buffalo’s of this study area revealed that the most of the S.

aureus isolates (83.

7 %) were resistant to one or more antimicrobial agent.

Eighty isolates (13.

2 %) were resistant to single antibiotic and 35 isolates (25.

7 %) showed resistance to 2 antimicrobial agents.

Multiresistance of S.

aureus isolates were found in 44.

8 % of S.

aureus isolates.

Resistance in cow and buffalo raw milk to Penicillin G was the most common finding followed by Ampicillin, Oxacillin, Amoxicilin/clavulanic acid, Erythromycin and Chloramphenicol.

On the other hand several isolates were found susceptible to the Ciprofloxacin, Cefoxitin, Tetracyclin, Rifampicin and Vancomycin antibiotics.

In sheep and goat raw milk resistance to Erythromycin was the most common finding followed by resistance to Amoxicillin-Clavulanic Acid, Ampicillin, Oxacillin and Penicillin G.

In conclusion preliminary information on prevalence of S.

aureus as milk contaminants as well as determination of antibiotic resistant S.

aureus isolates which may act as vehicles for the transmission of drug resistance are very important for both human and animal health care.