Molecular typing of Staphylococcus aureus isolated from Italian dairy products on the basis of coagulase gene polymorphism, multiple-locus variable-number tandem-repeat and toxin genes.
Coagulase gene restriction fragment length polymorphism (RFLP), six-locus variable-number tandem-repeat analysis patterns (MLVA) and detection of enterotoxin genes (se) (sea, sec, sed, seg, seh, sei, sej and sel) were used to determine the phylogenetic relationship among isolates of Staphylococcus aureus isolated from dairy products from different regions of Italy. A total of 25 Staph. aureus were subtyped into 16 coagulase genotypes by RFLP, and MLVA revealed marked genomic variability. Furthermore, 17 of the isolates harboured at least one toxin gene, with the predominance of sea, sed and sej among cow isolates and sec-sel among the goat and sheep strains. Combined RFLP, MLVA polymorphism and se genes were found to be useful techniques for discriminating several genetic variants in Staph. aureus isolates.
Stefano
Morandi
M
Institute of Sciences of Food Production, Italian National Research Council, via Celoria 2, 20133 Milan, Italy. stefano.morandi@ispa.cnr.it
Milena
Brasca
B
Roberta
Lodi
L
Lorenzo
Brusetti
B
D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics; D002417:Cattle; D003030:Coagulase / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D003611:Dairy Products / Q000382:microbiology*; D004731:Endotoxins / Q000235:genetics*; D014644:Genetic Variation; D007558:Italy; D011110:Polymorphism, Genetic; D013211:Staphylococcus aureus / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D020080:Tandem Repeat Sequences / Q000235:genetics
D001427:Bacterial Toxins; D003030:Coagulase; D004269:DNA, Bacterial; D004731:Endotoxins