Phenotypic and genotypic detection of virulence factors of staphylococcus aureus isolated from meat and meat products

الملخص EN

A total of 250 random samples of meat and meat products 50 of each meat, luncheon, burger, minced meat and sausage samples were collected from different butchers in Port-Said Governorate.

All samples were subjected to bacteriological examination for isolation and identification of Staph.

aureus.

The results revealed that the Staph.

aureus was isolated in a percentage of 55 (22%).

The prevalence of Staph.

aureus isolates in the examined meat, luncheon, burger, minced meat and sausage samples were 14%, 20%, 30% ,34% and 12%, respectively.

Coagulase positive Staph.

aureus (CPS) was isolated in percentage of 33(60%) from the examined meat, luncheon, burger, minced meat and sausage samples.

CPS isolates could be detected in meat, luncheon, burger, minced meat and sausage samples with a percentage of 57.15%, 600%, 60%, 58.82% and 66.66%, respectively.

The antibiotic resistance of coagulase positive Staph.

aureus using 14 antibacterial drugs by disk diffusion method were resistant to Cephalexin, Chloramphenicol, Cprofloxacin, Clindamycin, Erythromycin, Vancomycin, Trimethoprim + Sulphamethoxazole, Gentamicin and Streptomycin and found with a percentage of 87.88%, 84.85%, 75.76%, 72.73%, 72.73%, 69.70%, 63.64%, 60.60% and 57.58% respectively.

The conventional PCR assays were developed with specific primers for the detection of different types of virulence genes in 20 strong CPS strains as protein A in Staphyloccocus (spa), coagulase (coa), haemolysin (hlg) and intacellular adhesion (icaA) while multiplex PCR assay were developed to detect of two types of Staphylococcal enterotoxins (sea and seb).

The PCR amplification of the spa gene was 3/4, 2/4, 1/4, 1/4 and 2/4 coagulase positive Staph.

aureus at 226 bp from meat, luncheon, burger, minced meat and sausage respectively, While the all 20 confirmed coagulase positive Staph.

aureus was examined for coagulase (coa) gene using specific gene were positive at 360 bp.

0/4, 2/4, 0/4, 0/4 and 2/4.

Identified coagulase positive Staph.

aureus isolates were amplified the diagnostic DNA band successfully at 937 bp for hlg gene from meat, luncheon, burger, minced meat and sausage were 4/4, 3/4, 3/4, 3/4 and 2/4 respectively.

Amplification of the icaA gene was 4/4, 3/4, 3/4, 3/4 and 2/4 at 1315 bp from meat, luncheon, burger, minced meat and sausage respectively.

Multiplex PCR could successfully amplify the diagnostic DNA bands of 102bp and 164 bp, of genes for staphylococcal enterotoxins sea and seb, respectively.

The results showed that 1/4, 1/4, 2/4, 1/4 and 0/4 isolates of Staph.

aureus was positive for seb at 164 bp from meat, luncheon, burger, minced meat and sausage respectively.

While none of the samples were positive for sea.

The public health hazards of this microorganism, as well as improve quality status of meat and meat products were discussed.