Abstract

This study was carried out in order to investigate the occurrence of some virulence genes of Staphylococci isolated from cattle with mastitis. A total number of 133 milk samples (45 from clinical mastitis and 88 from subclinical mastitis) were collected from dairy cattle in Kafr El-Sheikh and EL Gharbia Governorates, Egypt. The samples were examined for the presence of Staphylococci by classical bacteriological methods and were further characterized geno-typically. A total of 41 Staphylococcus isolates were recovered from cattle with mastitis with an incidence of 30.8%. Among the isolates, 21(15.8%) of S. aureus [6 from clinical mastitis (13.3%) and 15 from subclinical mastitis (17%)] and 20 (15%) isolates of CNS [8 from clinical mastitis (17.7%) and 12 from subclinical mastitis (13.6%)] were identified phenotypically. All isolates were screened for the detection of binding protein A (spa-X), haemolysine type A (hla), Haemolysine type B (hlb), and toxic shock syndrome (tsst-1) by PCR. The obtained results revealed that the spa Xgene was detected in all Staphylococcus isolates recovered from subclinical mastitis while in clinical mastitis was detected with an incidence of 42.9%. Haemolysine type A was detected in clinical and subclinical mastitis with an incidence of 71.4% and 70% respectively, while haemolysine type B was detected in clinical and subclinical mastitis with an incidence of 28.5% and 40% respectively. Toxic shock syndrome was not detected in any of the isolates. The data in the study provided an overview on the distribution of some virulence genes related to Staphylococci isolated from cattle with mastitis in Egypt.