Detection and evaluation of properties of Polish strains of Arcanobacterium pyogenes isolated from pigs.

摘要

A genetic identification and evaluation of the properties of field isolates of A. pyogenes were conducted. Samples of internal organs as well as pathologically changed joints taken from dead pigs bred in Poland were used for testing. The isolation of bacteria was carried out according to standard microbiological methods. Properties of bacteria were evaluated based on their colour, size and shape on the agar plates and in smears stained with the Gram method as well as on results of biochemical tests. Genetic identification of isolates were based on the results of the elaborated polymerase chain reaction (PCR) test. Sensitivity to the most commonly used chemotherapeutics was evaluated by the disc diffusion test. Monocultures of transparent, small bacteria of pinhead size surrounded by a large haemolysis zone; Gram positive; fermented with acid production of glucose, fructose, galactose, lactose, cellobrose, trecholose, maltose, melarytose, mannose, glycogen, xylose and starch and with proteolytic activity were observed. A. pyogenes isolates were 100% sensitive to a wide spectrum of beta-lactams, with the exception of penicillin, for which 5% of the strains were resistant. 100% of isolates were also sensitive to oxytetracycline, doxycycline, enrofloxacin, tylosin and florfenicol and 95% of them were sensitive to tetracyclines, cephalosporin and lincospectin. A high percentage (90%) of sensitivity was registered for tiamulin, tulatromycin, gentamicin and norfloxacin. The highest resistance was evidenced in the case of neomycin (47% resistant strains) and sulfonamides with trimethoprim (45% of resistant strains). In PCR, the presence of genetic material of A. pyogenes was detected in the case of 56 tested strains (98.2%)..