INVESTIGATION OF PRESENCE OF METHICILLIN RESISTANT STAPHYLOCOCCI IN STUDENTS OF THE FACULTY OF VETERINARY MEDICINE AT THE UNIVERSITY OF BELGRADE

Abstract

Resistance to methicillin in staphylococci is considered to be one of the most dangerous forms of bacterial resistances to antibiotics. Methicillinresistant staphylococci (MRS) are zoonotic agents which cause local and systemic infections in humans and animals, oft en with a fatal outcome due to the absence of adequate antibiotic therapy. People colonized with strains of MRS are asymptomatic carriers and reservoirs of these strains in human populations. Th e aim of this research was to determine the prevalence of strains of MRS among clinically healthy students of the Faculty of Veterinary Medicine in Belgrade. Th e study was conducted on 100 volunteers: 62 males and 38 females. Given that staphylococci are expected to be found in the highest percentage in the nose and on the armpit skin, the swabs were taken from these regions of each person. Blood agar was innoculated immediately on taking the swabs Aft er the incubation and isolation, the staphylococci were identifi ed to species level. Their susceptibility to methicillin was tested in a disk-diff usion test with cefoxitin. All strains which were found to be resistant to cefoxitin were investigated for the presence of mecA gene with PCR. Staphylococci were isolated in 146 out of the 200 swabs taken: there were 79 nose swabs and 67 axillar swabs positive for these bacteria. Seventeen isolates were resistant to cefoxitin and the presence of the mecA gene was confi rmed in seven, four of which were taken from the nose and three from the axillary region. The results of this research show that, being 6%, the prevalence of mecA-positive staphylococci in the population of clinically healthy students of veterinary medicine is significant. Th e percentage of methicillin-resistant staphylococci was higher in nose than in the axillar region of the students.