Determinación de la presencia de cepas de Staphylococcus aureus resistentes y multiresistentes aislados en quesos frescos artesanales elaborados en zonas rurales de Riobamba.

Abstract

The present research determined the presence of Staphylococcus aureus strains resistant and multi-resistant isolated from artisanal cheese produced in rural areas of Riobamba, this study was carried out in 6 dairies (San Juan, Quimiag and Pungalá), the sample is collected periodically during the months of November and December 2015. The presence of Staphylococcus aureus was identified and the specimens were planted on Petrifilm Staph 3M plates for its quantification and isolated colonies were identified later with conventional methods, Agar Mannitol was used obtaining growth and fermentation in 15 samples of Staphylococcus aureus strains isolated, it was confirmed by Tincion Gram, tests of catalase and coagulase. The prevalence of Staphylococcus aureus in cheese analyzed was 83.33%. The resistance to antibiotics (Penicillin, Cefoxitin, Tetracycline, Amikacin, Vancomycin, Ciprofloxacin, Clindamycin and Erythromycin), were evaluated by the Kirby-Bauer disk diffusion method, and the results obtained were: Staphylococcus aureus strains resistant to Penicillin by 100%; Cefoxitin 33.33% resistance and 66,67% sensitivity; Tetracycline 13.33% resistance and 86.67% sensitivity; Amikacin 6.67% resistance and 93.33% sensitivity; Vancomycin100% of sensitivity; Ciprofloxacin 100% sensitivity; Clindamycin 20% resistance and 80% sensitivity; Erythromycin 20% sensitivity and 80% intermediate resistance. This study concluded that the quantification results of cheeses were high, and these do not comply with General Standards of Fresh Cheese non Matured, this cheese is not suitable for human consumption because it can cause problems of food poisonings and resistance to antibiotics in humans. This study recommended to train producers and handlers involved in the production of cheeses in best practices of manufacturing and educate the community about the correct use of antibiotics in animals from which gets the raw material for the manufacture process cheese.