Geographical variation in the presence of genes encoding superantigenic exotoxins and β-hemolysin among Staphylococcus aureus isolated from bovine mastitis in Europe and USA

被引：83

作者：

Larsen, HD ^{[1
]}

Aarestrup, FM ^{[1
]}

Jensen, NE ^{[1
]}

机构：

[1] Danish Vet Lab, DK-1790 Copenhagen V, Denmark

来源：

VETERINARY MICROBIOLOGY | 2002年 / 85卷 / 01期

关键词：

Staphylococcus aureus; mastitis; toxin; superantigen; virulence factor; beta-hemolysin;

D O I：

10.1016/S0378-1135(01)00478-3

中图分类号：

Q93 [微生物学];

学科分类号：

071005 ; 100705 ;

摘要：

The object was to examine the geographical variation in the presence of superantigenic exotoxins and beta-hemolysin among epidemiologically independent Staphyirrcoccus aureus isolates from bovine mastitis. A total of 462 S. aureus isolates from nine European countries and USA were examined for the presence of genes encoding staphylococcal enterotoxins A-E, and H, toxic shock toxin-1 (TSST-1), and beta-hemolysin, and 128 of these were examined for exfoliative toxins A and B. The detection was done by PCR. Phenotypic methods were used to confirm the PCR-results. None of the 128 isolates carried the genes for exfoliative toxin A or B. The total proportion of isolates in which superantigenic exotoxins were detected varied from 2% (one isolate) of the Danish isolates to 65% (32 isolates) of the Norwegian isolates. This marked and highly significant geographical variation was also present for the individual exotoxins. The genes encoding enterotoxin C, TSST-1, and enterotoxin D were the most common superantigens. The present and earlier studies demonstrate that the superantigenic exotoxins that were investigated in this study, do not play a role in the pathogenesis of bovine S. aureus mastitis. In contrast to the geographical variation among superantigenic exotoxins, 97% of the isolates were PCR-positive for and/or produced beta-hemolysin on 5% calf blood agar. Except for three isolates, the Norwegian isolates were PCR-negative, but positive on 5% calf blood agar. Sequence variation in the primer regions in the beta-hemolysin encoding gene of the Norwegian isolates is suggested, and should be investigated further. The consistent presence of beta-hemolysin suggests that this factor, or a co-existing gene correlated to beta-hemolysin, may be an active virulence factor in the pathogenesis of bovine S. aureus mastitis. (C) 2002 Elsevier Science B.V. All rights reserved.

引用

页码：61 / 67

页数：7

共 23 条

[1] Frequency of α- and β-haemolysin in Staphylococcus aureus of bovine and human origin -: A comparison between pheno- and genotype and variation in phenotypic expression [J].