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Genes associated to virulence and multidrug resistance in strains of Trueperella pyogenes isolated from bovine mastitis and other diseases of domestic animals

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Rafaela Mastrangelo Risseti
Total Authors: 1
Document type: Master's Dissertation
Press: Botucatu. 2016-06-07.
Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
Defense date:
Advisor: Márcio Garcia Ribeiro

Trueperella pyogenes are opportunistic bacterium characterized by suppurative infections in domestic animals, commonly refractory to conventional therapy. Recently, genes which encode exotoxin pyolysin (plo), and factors that promote adhesion of T. pyogenes to host cells, such as fimbriae (fimA, fimC, fimE, fimG), neuraminidases (nanH, nanP), and collagen-binding protein (cbpA) have been associated to virulence of pathogen. The aim of present study was investigate occurrence of multi-drug resistance of isolates, as well the presence of genes plo, fimA, fimC, fimE, fimG, nanH, nanP, and cbpA in 41 T. pyogenes strains obtaned from bovine, goats, sheep, horses, and dog isolated among different clinical manifestations. T. pyogenes was identified predominantly in mastitis (46.3%), abscesses (19.5%), pneumonia (9.8%), metritis (9.8%), lymphadenitis (7.3%), followed by encephalitis (4.9%) and orchitis (2.4%). The strains showed major in vitro sensitivity to florfenicol (97.6%), azithromicin (97.6%), tetracycline (95.2%), ceftiofur (92.7%), penicillin (92.7%), ampicillin (92.7%), gentamicin (90.3%), and erythromycin (87.8%). In contrast, highest frequency of resistance among isolates was observed to bacitracin (46.3%), neomycin (31.7%), lincomycin (31.7%), and trimethropim/sulfamethoxazole (24.3%). Antimicrobial multiple resistance index - AMRI (>0.3) was found in 13 (31.7%) isolates, particularly in bovine mastitis cases. Among multi-drug resistant isolates to 3 or more group of antimicrobials, 12 (92.3%) were identified in bovine, predominantly in mammary infections. The most common genes detected among isolates were: plo (40/41=97.6%), fimA (36/41=87.9%), nanP (34/41=82.9%), fimE (32/41=78.0%), nanH (28/41=62.3%), fimC (23/41=56.0%), and cbpA (5/41=12.2%). The major associations between genes of isolates were plo, fimA, fimE, nanH, and nanP (10/41=24.4%), and plo, fimA, fimE, fimC, nanH, and nanP (8/41=19.5%), mainly in bovine mastitis. To ... (AU)

FAPESP's process: 13/17293-0 - Phenotypic characterization and virulence-associated genes in strains of Trueperella (Arcanobacterium) pyogenes isolated from bovine mastites
Grantee:Rafaela Mastrangelo Risseti
Support Opportunities: Scholarships in Brazil - Master