Genetic Characterization of Resistant S. Aureus Strains Isolated From Cow's Milk with Mastitis Healthcare

Mastitis therapy is generally unsuccessful due to pathological changes that occur in the breast as a result of the inflammatory response, factors associated with the causes of mastitis, the pharmacokinetic properties of antimicrobial drugs, etc. The main reason for the low effectiveness of antibiotic treatment of mastitis caused by staphylococci is especially, among other things, the resistance of bacteria, where is recognized that Staphylococcus aureus is the first penicillinresistant bacteria. Laboratory techniques based on phenotypic characteristics of resistance have low sensitivity. PCR (Polymerase Chain Reaction) as a method for detecting gene mecA is considered as gold standard test. Detection of mecA gene through PCR is one of the most effective methods for the detection of MRSA. Using this method we identified six methicillin-resistant strains of S. aureus isolated from cow’s milk with mastitis. Our study presents the first survey carried out in our country regarding the presence of the mecA gene for antibiotic-resistant strains of S. aureus which is isolated from cow’s mastitis. This study has a special importance for food products of animal origin, like milk contaminated with MRSA may constitute a main source of consumer’s infection. The treatment of cow’s mastitis is related to the nature of the etiological agent, susceptibility of antibiotics, clinical signs, immune system and biological condition of the body. Bacteriological diagnosis is not sufficient to have an effective treatment of mastitis, whether bacterial agents isolated from milk samples are not tested for its sensitivity to antimicrobial preparations. Numerous studies conducted in this area have concluded that microbial agents isolated from clinical cow’s mastitis will not differ in sensitivity to antibiotics from microbial agents isolated from sub-clinical cases of mastitis. Among the in-vitro sensitivity tests, antibiogram (agar diffusion technique) represents the most common of the tests when we seek to identify the most effective antibiotics against recognized pathogens in order to install a successful therapy. Mastitis therapy is generally unsuccessful due to pathological changes that occur in the breast as a result of the inflammatory response, factors associated with the causes of mastitis, the pharmacokinetic properties of antimicrobial drugs, etc. The main reason for the low effectiveness of antibiotic treatment of mastitis caused by staphylococci is especially, among other things, the resistance of bacteria, where is recognized that Staphylococcus aureus is the first penicillin-resistant bacteria. Laboratory techniques based on phenotypic characteristics of resistance have low sensitivity. PCR (Polymerase Chain Reaction) as a method for detecting gene mecA is considered as gold standard test (Eva Juhasz-Kaszanyitzky 2007).