Characterization of bacteria of the genus Staphylococcus isolated from the eggs of Japanese quail (Coturnix coturnix japonica)

The study attempted to analyse and characterize bacteria of the genus Staphylococcus isolated from the surface and contents of quail eggs, taking into account their phenotypic properties, biochemical reactions, antibiotic sensitivity patterns, and PCR to test for the presence of the mecA gene, which is responsible for resistance to methicillin. The study included 45 strains of the genus Staphylococcus isolated from the whites, yolks and shells of table quail eggs. The results obtained indicate that a fairly high percentage of the retail quail eggs tested were contaminated with Staphylococcus bacteria. Among the species isolated (11 in total), the most frequently occurring strains were of Staphylococcus hominis (26.7%), followed by Staphylococcus aureus (15.6%), S. xylosus and S. lentus (13.3% each), while percentages of the other Staphylococcus species were under 10%. The Staphylococcus strains tested had highly differentiated biochemical and enzymatic properties. As many as 7 biotypes were distinguished among the 7 S. aureus isolates, 6 biotypes within the species S. xylosus (6 strains tested), 5 biotypes among the 6 strains of S. lentus, but only 4 biotypes among the 12 S. hominis strains. The antibiotic sensitivity testing showed 15.5% of the strains to be resistant to one or more of the therapeutic agents tested. Moreover, some isolates exhibited intermediate sensitivity to the drugs, particularly to gentamicin (24.4%), neomycin (31.1%), streptomycin (46.7%) and Linco-Spectin (48.9%).