Staphylococcus aureus in commercial breeder layer flocks

Four flocks of Layer breeders, consist of 28000 (7000 birds each) at 25 weeks of age, hatchery and one day old chicks were subjected to swab sampling in order to isolate Staphylococcus aureus during the period from May till June 2008. Results revealed that more than half of the overall swab samples were positive (52.04%). Different isolation rates were recorded between four flocks, ranging from 62.5 to 79.16%. Hatchery samples revealed that working surfaces were heavily contaminated with S. aureus (75%), compared with the relatively low contaminated egg flats and egg shells. One day old chick samples show relatively low percentage of S. aureus isolation (29.1%). Antimicrobial sensitivity of 20 S. aureus isolates were surveyed for susceptibilities to a panel of 16 antimicrobial agents. S. aureus were 100% sensitive to five antimicrobials, namely; enrofluxacin; methicillin; trimethoprim with sulfamethoxazol and vancomycin, while in the opposite direction, 100% resistancy were recorded for two antimicrobial, ampicillin and amoxicillin. Graded sensitivity was observed in other antimicrobials, include: gentamycin, chloramphinicol, penicillin, erythromycin, ciprofloxacin, colistin, lincomycin, cephaloxin and doxycillin. The importance of the organism in breeder layers health was discussed.