Mastite estafilocócica por MRSA em pequenos ruminantes no Estado de OHIO - EUA

• Autor(a) principal: Moura, Guilherme Santana de
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/15361
• topic: Mastite em pequenos ruminantes; LA-MRSA; ST398; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Mastitis has a large impact on the economy as well as on animal welfare in sheep and goat production. While several microorganisms can cause mastitis in small ruminants, Staphylococcus aureus is one of the most important pathogen. An increasing percentage strains showing resistance against methicillin (Methicillin Resistent Staphylococcus aureus - MRSA) have been recovered from different sources and can potentially cause severe illness in humans and animals. Livestock associated MRSA (LA-MRSA) are strains often isolated from animals, veterinarians and people who are in contact to food animals and the sequence type 398 is the frequent LA-MRSA strain associated to human infections. This paper discusses mastitis cases caused by MRSA strains in goats and sheep herds in Ohio - USA. One sheep showing fever, reactive mammary lymphnodes, thinness, muscle weakness and mastitis in both mammary glands was examined. One teat had a fistula draining pus. A sample of purulent discharge was collected and sent for analisys. Phenotypical and genotypical tests were performed. Sample was nuc and mecA positive confirming genetically the Methicillin resistant S. aureus. MLST revealed that the tested MRSA isolate belonged to the clonal lineage ST398. This is the first MRSA report causing mastitis in sheep in USA. Mostly important, the identification of ST398 warrants further epidemiological investigations about epidemiology of this pathogen in animal production systems. The second study aimed to investigate occurrence of Methicillin Resistant S. aureus (MRSA) associated with intramammary infections in goat herds in Ohio State, USA. A total of 120 milk samples and 120 teat-swab samples were collected from five farms. After conventional isolating and phenotypic characterization of colonies, molecular characterization was also performed through PCR for nuc and mecA genes for MRSA confirmation and clonal complexes determined by MLST. Fifteen (6.2%) positive S. aureus samples were found in this study; nine from milk and five from teat skin samples. Four (2%) MRSA isolates were detected and belonged to clonal complexes ST133 and ST5. Three (1.25%) coagulase-negative isolates were shown to harbor the mecA gene. This study indicates 17 that MRSA belonging to clonal complex 133 can be associated with intrammamary infections in goat herds in US and the identification of the MRSA ST5 is of special concern, since it’s an important pathogen to humans.