The Journal of Infection in Developing Countries, 2015
Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-nega... more Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-negative staphylococci (CoNS) are increasing in importance as causeof bovine intramammary infection (IMI) throughout the world in recent years. CoNShave been isolated from milk samples collected from cows with clinical andsubclinical mastitis in several countries. Identification of mastitis pathogensis important when selection appropriate antimicrobial therapy.Methodology: A total of 93 strains of Staphylococcusspp isolated from bovine clinical andsubclinical mastitis in Argentina during 2010-2013 were identified by Restriction Fragment Length Polymorphism (RFLP)-PCR using the gap gene. The isolates were tested by PCR for the presence of blaZ gene and mecA gene and were tested by disk diffusion for the susceptibilityto penicillin and cefoxitin. Results: The most common CoNS species was S.chromogenes 46.2% (43/93), followed by S. devriesei 11.8% (11/93) and S. haemolyticus 9.7% (9/93). The bl...
Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-nega... more Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-negative staphylococci (CoNS) are increasing in importance as cause of bovine intramammary infection throughout the world in recent years. CoNS have been isolated from milk samples collected from cows with clinical and subclinical mastitis in several countries. Identification of mastitis pathogens is important when selecting appropriate antimicrobial therapy. Methodology: A total of 93 strains of Staphylococcus spp isolated from bovine mastitis in Argentina between 2010 and 2013 were identified by PCR-restriction fragment length polymorphism (PCR-RFLP) using the gap gene and were tested for the presence of blaZ and mecA genes by PCR and for the susceptibility to penicillin and cefoxitin by disk diffusion. Results: The most common CoNS species was S. chromogenes 46.2% (43/93), followed by S. devriesei 11.8% (11/93) and S. haemolyticus 9.7% (9/93). The blaZ gene was detected in 19 (20.4%), but only 16 (17.2%) isolates were resistant to penicillin; the mecA was detected in 6 (6.5%) isolates but only 4 (4.3) were resistant to cefoxitin. The 6 mecA-positive isolates showed oxacillin MICs ≥ 0.5 μg/ml. Discussion: CoNS are important minor mastitis pathogens and can be the cause of substantial economic losses. The presence of methicillin resistant isolates emphasizes the importance of identification of CoNS when an intramammary infection is present because of the potential risk of lateral transfer of resistant genes among staphylococcal species.
The Journal of Infection in Developing Countries, 2015
Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-nega... more Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-negative staphylococci (CoNS) are increasing in importance as causeof bovine intramammary infection (IMI) throughout the world in recent years. CoNShave been isolated from milk samples collected from cows with clinical andsubclinical mastitis in several countries. Identification of mastitis pathogensis important when selection appropriate antimicrobial therapy.Methodology: A total of 93 strains of Staphylococcusspp isolated from bovine clinical andsubclinical mastitis in Argentina during 2010-2013 were identified by Restriction Fragment Length Polymorphism (RFLP)-PCR using the gap gene. The isolates were tested by PCR for the presence of blaZ gene and mecA gene and were tested by disk diffusion for the susceptibilityto penicillin and cefoxitin. Results: The most common CoNS species was S.chromogenes 46.2% (43/93), followed by S. devriesei 11.8% (11/93) and S. haemolyticus 9.7% (9/93). The bl...
Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-nega... more Introduction: Bovine mastitis is a frequent cause of economic loss in dairy herds. Coagulase-negative staphylococci (CoNS) are increasing in importance as cause of bovine intramammary infection throughout the world in recent years. CoNS have been isolated from milk samples collected from cows with clinical and subclinical mastitis in several countries. Identification of mastitis pathogens is important when selecting appropriate antimicrobial therapy. Methodology: A total of 93 strains of Staphylococcus spp isolated from bovine mastitis in Argentina between 2010 and 2013 were identified by PCR-restriction fragment length polymorphism (PCR-RFLP) using the gap gene and were tested for the presence of blaZ and mecA genes by PCR and for the susceptibility to penicillin and cefoxitin by disk diffusion. Results: The most common CoNS species was S. chromogenes 46.2% (43/93), followed by S. devriesei 11.8% (11/93) and S. haemolyticus 9.7% (9/93). The blaZ gene was detected in 19 (20.4%), but only 16 (17.2%) isolates were resistant to penicillin; the mecA was detected in 6 (6.5%) isolates but only 4 (4.3) were resistant to cefoxitin. The 6 mecA-positive isolates showed oxacillin MICs ≥ 0.5 μg/ml. Discussion: CoNS are important minor mastitis pathogens and can be the cause of substantial economic losses. The presence of methicillin resistant isolates emphasizes the importance of identification of CoNS when an intramammary infection is present because of the potential risk of lateral transfer of resistant genes among staphylococcal species.
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