Molecular Typing of Staphylococcus aureus Isolated from Cows, Goats and Sheep with Intramammary Infections on the Basis of Gene Polymorphisms and Toxins Genes

Abstract

We investigated 116 Staphylococcus aureus isolates from cows, goats and sheep with intramammary infections (IMI) in Italy to provide information about the spread of enterotoxigenic strains and to compare strains isolated from different ruminant species. The isolates were typed by restriction fragment length polymorphism (RFLP) analysis of the coagulase (coa) gene, by analysis of polymorphisms of the X region of protein A (spa) gene and by detection of genes encoding enterotoxins (sea, seb, sec, sed, see, seg, seh, sei, sej and sel). Seven different coa types and 12 different spa types were distinguished. On the basis of polymerase chain reaction-RFLP, 29 different coa subtypes were identified. Two different coa subtypes accounted for 49% and 67% of bovine and ovine isolates respectively. Only seven coa subtypes were observed in isolates from more than one host species and no coa subtype was present in isolates from all three ruminant species. Furthermore, 85 of the isolates (73%) harboured at least one enterotoxin gene (se) with a predominance of sea, sed and sej among isolates from bovine IMI, and sec and sel among isolates from caprine and ovine IMI. Comparing the S. aureus isolates on the basis of gene polymorphisms and presence of se genes, significant differences were found in distributions of genotypes among isolates from cows, goats and sheep.

Characterization of Genes Encoding Virulence Determinants and Toxins in Staphylococcus aureus from Bovine Milk in Central Italy

“…A close genetic association has been observed between sea, sed and sej [15] and between sed and sej, according to the results of Vimercati et al [38]. Both genes are located on plasmid pIB485 and are separated by an intergenic region of less than 1 Kb [39].…”

Panton–Valentine leukocidin and some exotoxins of Staphylococcus aureus and antimicrobial susceptibility profiles of staphylococci isolated from milks of small ruminants

“…Vimercati et al (2006) carried out a study on the S. aureus isolates comparing them on the basis of the presence of se genes, where they found significant differences between the isolates from intramammary infected cows (n=51, 75%), goats (n=22, 77%) and sheep (n=43, 70%). They also reported that sec and sel genes have the higher frequency in ovine than bovine isolates.…”

“…These enterotoxins are produced by both clinical and subclinical mastitis isolates of S. aureus (Contreras et al 2007;Argudin et al 2010). In contrast to bovine isolates (Boynukara et al 2008;Karahan et al 2009;Morandi et al 2009;Wang et al 2009), a few data are available in the literature regarding the spreading of enterotoxigenic S. aureus isolated from small ruminants in recent years (Aires-de-Sousa et al 2007;Vimercati et al 2006;Maslankova et al 2009). …”

Subklinik mastitisli inek sütlerinden izole edilen Staphylococcus aureus izolatlarında bazı toksin genleri ve metisilin direnç geninin araştırılması

“…İnek mastitisli sütlerden izole edilen S. aureus izolatlarının stafilokokal enterotoksin genlerinin tespitiyle ilgili yapılan çalışmaların çoğunda (11,21,23,32), sunulan bu çalışmanın bulgularına benzer olarak seb, see ve seh genleri hiç izole edilmemiş veya çok az oranlarda izole edilmiştir. Diğer taraftan bazı çalışmalarda (29,30), yüksek oranlarda sea geni tespit edilirken; bazı çalışmalarda (7,8,11,21,33) Subklinik mastitisli ineklerin sütlerinden izole edilen S. aureus izolatları değişik oranlarda da olsa bir veya daha fazla stafilokokal enterotoksin kodlayan genleri taşıyabilmektedirler. Enterotoksinlerin S. aureus'ların konakçı savunma sistemini etkileyerek kolonizasyonları için uygun bir çevre oluşmasına yardım eden önemli virülens faktörlerinden (19) olduğu düşünülürse, mastitislerin patogenezinde bu toksinlerin önemli olabileceği göz önüne alınmalıdır.…”

“…Son yıllarda insan ve veteriner hekimliği alanlarında S. aureus izolatlarının sahip olduğu virulens faktörlerin tespitinin önemi vurgulanmakta ve çalışmaların önemli bir kısmı S. aureus virülens faktörlerinin çeşitli genotipik yöntemlerle değerlendirilmesi konusunda yapılmaktadır (11,22,28,29,30,32).…”