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

Abstract

ABSTRACT. The aim of this study was to evaluate the genotypic characteristics of Staphylococcus aureus isolates (n=170) from bovine milk collected from seven dairy farms in Italy. On the basis of cultural and biochemical properties and by amplification of the 23S rRNA specific to S. aureus, all isolates were identified as S. aureus. To genotypically characterize S. aureus isolates, genes encoding virulence determinants (nuc, clfA, spa-IgG-binding, spa-X-region, fnbA and fnbB, cap5 and cap8) and staphylococcal enterotoxins (sea, seb, sec, sed, see, seg, seh, sei, sej) were investigated using a PCR technique. The results showed that the isolates of S. aureus in each farm had the same genotypic characteristics, while the isolates genotipically differed between the different farms. The present study might help to understand the distribution of prevalent S. aureus strains in dairy farms.

Virulence Factor Profile of <i>Staphylococcus aureus</i> Isolated from Bovine Milk from Brazil

“…In another study, Borges et al [17] observed S. aureus in 67% (16/24) of isolates from raw milk. Worldwide, several studies suggest that the S. aureus isolation rates in milk can vary from 13.5% to 64.7% [12] [18] [19]. Furthermore, in the present study, a high frequency of isolation of S. aureus was observed in samples collected directly from bulk tanks.…”

“…Staphylococci cultures in 2 mL of TSB medium were used for DNA extraction according to the method described by Fan et al [11]. The isolates were submitted to PCR for detection of virulence factors genes: sea (Staphylococcal enterotoxins type A), seb (Staphylococcal enterotoxins type B), sec (Staphylococcal enterotoxins type C), pvl (Panton-Valentine Leucocidin), clfA (Clumping factor) and spa (IgG-binding region and the X-region of protein A) using primers described by Proietti et al [12]. The primer sequences of the sea, seb, sec, PVL, spa and CflA genes are described in Table 1.…”

Molecular epidemiology and virulence characteristics of Staphylococcus aureus nasal colonization in medical laboratory staff: comparison between microbiological and non-microbiological laboratories

“…SCC mec typing of MRSA strains was conducted by a multiplex PCR method as previously described [ 13 ]. The presence of the genes that code for Panton-Valentine leukocidin ( lukF-PV/lukS-PV or pvl ), twelve staphylococcal enterotoxins ( sea~see, seg~sej and sem-seo ), two exfoliative toxins ( eta and etb ), four haemolysins ( α-hemolysin, β-hemolysin, δ-hemolysin, and γ-hemolysin ), three biofilm information-related genes ( ica A, ica D and bap ), and the toxic shock syndrome toxin ( tsst- 1) and mec A gene were determined using PCR as previously reported, with some modification [ 14 , 15 ].…”

Aerobic Mesophilic, Coliform, Escherichia coli, and Staphylococcus aureus Counts of Raw Meat from the Formal and Informal Meat Sectors in South Africa

“…Hence, due to their ability to cause numerous sporadic cases and foodborne disease outbreaks in humans, they have become a significant public health threat [ 10 , 11 , 12 ]. Staphylococcus aureus , on the other hand, produces a variety of potent staphylococcal enterotoxins (SEs), which are resistant to inactivation by gastrointestinal proteases and are consequently responsible for staphylococcal food poisoning [ 10 , 13 ]. Severe gastroenteritis can develop within one to seven hours after the consumption of Staphylococcus aureus contaminated food, leading to diarrhoea, vomiting, and dehydration.…”