Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  coagulase-negative staphylococci
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The aim of the present study was to assess the haemolytic and proteolytic activity of coagulase- negative staphylococci (CNS) isolated from cows with mastitis. The study was conducted on 100 CNS strains: S. xylosus (n=28), S.chromogenes (n=26), S.haemolyticus (n=25), S. sciuri (n=14), S. warneri (n=4), S.hominis (n=2), S.saprophyticus (n=1); 22 CNS were isolated from cows with clinical mastitis and 78 from those with subclinical mastitis. The CNS studied showed the ability to produce only α-haemolysin and belonged to one strain – S. haemolyticus (21.0% of isolated CNS strains). Haemolysin-positive CNS were responsible for both clinical and subclinical mastitis (22.7% and 20.5%, respectively). The ability to produce protease was found in 31.0% of CNS belonging to two strains: S. chromogenes and S. sciuri. Protease-positive CNS were the etiological factor of both clinical and subclinical mastitis (31.8% and 30.8%, respectively). All S. xylosus, S. warneri, S. hominis, and S. saprophyticus strains were found protease-negative and haemolysin-negative, irrespective of whether they caused clinical or subclinical mastitis in cows.
Staphylococci are the main aetiological factor of bovine mastitis in many dairy herds. Traditionally, coagulase-negative staphylococci (CNS) were considered a normal skin microbiota. Lately the role of CNS in bovine mastitis has increased, as in some countries these pathogens had started to outnumber other mastitis aetiological factors. Given the scale of mastitis problems, the intensive use of antibiotics in dairy cattle, the number of animals and the consumption of milk products there is an urgent need to highlight the threat to both human and animal health originating from CNS. The knowledge of how CNS mastitis develops, spreads in herd and persists is limited. Bovine strains of CNS are poorly characterised; moreover, they are characterised mainly in terms of phenotypes. This review summarises knowledge on the characterisation of CNS strains, stressing the role of the bacterial genotype, in the context of the risk to human and animal health. Selected CNS virulence factors that play a role during mastitis in dairy cattle are listed and described in this paper. They have been selected subjectively by the authors in view of their significance for public health (toxins, antimicrobial resistance) and their importance for animal health (formation of biofilm, prevention of phagocytosis intracellular survival) and mastitis outcome.
The aim of this study was to evaluate methicillin resistance detection methods currently used when studying coagulase-negative staphylococci (CoNS). The resistance to oxacillin of 142 strains from seven species of CoNS isolated from the Intensive Care Unit environments was tested. The methods used were: disc diffusion test with cefoxitin (FOX₃₀) and oxacillin (OX₁), oxacillin agar screen test with 6 mg/l of oxacillin (MHOXA), latex test for PBP2a (LA) and detection of mecA via PCR. One hundred and one isolates were methicillin-resistant in at least one of methods used, but only 74 were mecA -positive. Of the 68 mecX-negative strains: two were positive by OX₁, the LA and MHOXA methods; three by the LA and MHOXA; and 22 only by OX₁, test. Most of these strains were from the novobiocin-resistant CoNS group. The results obtained for all tested strains using FOX₃₀ showed complete concordance with the presence of the mecA gene.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.