Pesquisa de Staphylococcus aureus e genes de resistência aos β-lactâmicos e codificadores de enterotoxinas em queijo coalho artesanal elaborado com leite de cabra

Abstract

The objective of this study was to evaluate the level of contamination and to investigate coding genes for resistance to betalactam and staphylococcal enterotoxins in Staphylococcus aureus isolated from artisanal curd cheese produced with goat's milk in the state of Pernambuco. The method of microbiological analysis used was in accordance with Normative Instruction 62/2003 of MAPA. The growth of characteristic (typical and atypical) colonies of S. aureus in Baird Parker agar was observed in 100.0% of the samples and the bacterial count of this genus ranged from 7.0×103 to 8.6×106 CFU/g. All samples had values of CFU/g above the maximum required by Resolution-RDC nº12/2001 – ANVISA. There was no detection of any of the staphylococcal enterotoxin encoding genes investigated. Regarding resistance genes, the blaZ gene was detected in 42.6% of S. aureus isolates and the mecA gene was not detected. At the Minimum Inhibitory Concentration, 7.4% of the isolates were resistant to oxacillin. The contamination of this type of cheese can be associated to factors of animal handling, failures in the production chain, lack of basic care in the good manufacturing practices in the process of elaboration of the cheeses. The high degree of contamination of the rennet cheese indicates the need to improve the assistance to producers, to increase the inspection of commercial establishments and to carry out further microbiological studies on the quality of goat cheese in Pernambuco.