Presença de Staphylococcus aureus resistentes à meticiilina (MRSA) em queijos de coalho produzidos no estado do Ceará e seu perfil de resistência e genes de virulência

Abstract

Staphylococcus aureus is a microorganism present in the microbiota of humans and in several warm-blooded animals. Because of agricultural activities, these microorganisms are often transferred to foods, such as milk and dairy products, which can lead to serious foodborne illnesses. For decades, several studies have demonstrated the ability of these microorganisms to acquire resistance to antimicrobials, including methicillin, and thus become a major public health problem. Methicillin, in turn, was the first synthetic penicillin resistant to the penicillinases

produced by S. aureus, it even becomes the prototype molecule of the group of anti- staphylococcal penicillins, which should be fully effective in combating this

microorganism. The present study evaluated the presence of methicillin-resistant S. aureus (MRSA) in 112 samples of rennet “coalho” cheese from 56 dairy farms and producing farms in 28 cities in all mesoregions of the State of Ceará, also observing the presence of genes coding for enterotoxins and toxin from toxic shock syndrome, as well as the presence of the blaZ gene and resistance to methicillin. The research found 69 strains of S. aureus, 10.14% of which possess the methicillin resistance mecA gene in cheeses from 6 different cities, the capital of the state, Fortaleza, having the highest prevalence (57.14%). It was also found that 55.07% of the strains of S. aureus had the blaZ gene and 7.25% demonstrated resistance to methicillin in plate disc diffusion tests. The resistance profile showed that 14.49% of the strains of S. aureus were not resistant to any antimicrobial, while 42.03% were resistant to 3 or more drugs. The greatest resistance presented was erythromycin, followed by amoxicillin and sulfamethoxazole/trimethoprim. The study did not show the presence of isolated carriers of toxigenic genes. These findings demonstrate that strict supervision of production processes in the dairy industry is necessary from the production stage, avoiding contamination and possible problems for consumers.