Virulence profile and genetic variability of Staphylococcus aureus isolated from artisanal cheese
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2016
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The objectives of this study were to characterize
Staphylococcus aureus isolated from artisanal and in dustrialized Minas frescal cheeses, to determine their
antimicrobial susceptibility profile as well as the ge netic similarity among the isolates. The isolates were
also tested for staphylococcal enterotoxin genes and
other virulence factors. Fifty-six artisanal raw milk
cheeses sold at street fairs and 10 industrialized cheeses
commercialized in supermarkets of Goiânia, Goiás,
were analyzed. Staphylococcus aureus was confirmed in
19 samples (33.9%) of artisanal cheese by detection of
femA gene, in which 29 isolates were obtained. These
isolates were submitted to the antimicrobial suscepti bility test and classified into 9 different profiles (A–I).
Thirteen isolates (44.8) were resistant to penicillin
and 3 (10.3) to tetracycline, with 2 (7.4) resistant to
both. The multiplex PCR technique was performed
to detect virulence genes that code for the production
of hemolysins (Hla and Hlb), toxic shock syndrome
toxin (TSST-1), exfoliative toxins (ETa and ETb), and
staphylococcal enterotoxins [SE; SEA–SEE, SEG–SEJ,
SEM–SEO]. All the isolates amplified for the hla gene
and 14 (48.3%) for the hlb gene. The seh gene was the
most frequently detected (n = 11, 37.9%), followed by
seo gene (n = 3; 10.3%). In one isolate (3.4%), 4 entero toxins genes were detected, and in another, 6 (3.4%)
were detected. The comparison performed by pulsed field gel electrophoresis of the 29 isolates revealed 18
genotypic profiles, which were grouped into 5 clusters.
The genotyping found high genetic similarity among
the isolates. Identical isolates were obtained from dif ferent samples and one sample showed more than one
genetically different isolate. The high prevalence of S.
aureus in the Minas Frescal cheese samples, as well as
the detection of toxin encoding genes identified in this
study, warns of the necessity to reduce the contamina tion levels in this type of cheese through monitoring and
controlling the production and trade of the product.
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Staphylococcus aureus, Cheese, Antimicrobial resistance, Staphylococcal enterotoxin
Citação
FERREIRA, M. A. et al.Virulence profile and genetic variability of Staphylococcus aureus isolated from artisanal cheese. Journal of Dairy Science,
Champaign , v. 99, n. 11, p. 8589-8597, 2016. DOI: 10.3168/jds.2015-10732. Disponível em: https://www.sciencedirect.com/science/article/pii/S0022030216305501?via%3Dihub. Acesso em: 4 jun. 2025.