Produção de biofilme, perfil de sensibilidade e aspectos epidemiológicos de espécies fúngicas e algas do gênero Prototheca isoladas de casos de mastite bovina

• Ano de defesa: 2016
• Autor(a) principal: Franckin, Tarsila [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Mastite bovina; Leveduras; Algas; Biofilme; Fluconazol
• Link de acesso: http://hdl.handle.net/11449/138105

Although bacteria are the most prevalent agents in bovine mastitis, increasingly literature reported cases of the disease caused by fungi and algae of the genus Prototheca. This study aimed to generate new knowledge about the etiology and pathogenicity of bovine mastitis agents caused by fungi and algae of the genus Prototheca from morphophysiological and molecular identification, besides analysis of biofilm production capacity and susceptibility profile. For this, morphophysiological and molecular analyzes were performed of 33 yeast isolates and 40 algae of the genus Prototheca obtained from clinical and subclinical mastitis cases, systematically collected in five dairy properties in the states of São Paulo and Minas Gerais, as part of their respective mastitis control programs. The results indicated that all algae are belonging to the species Prototheca zopfii and, among the yeasts, the following species have been identified: Pichia kudriazevii (n=16; 48.5%), Candida akabanensis (n=8; 24.2% ), Candida tropicalis (n= 3; 9.1%), Cyberlindnera jadinii (n= 2; 6.1%), Candida glabrata (n= 1, 3%), Candida parapsilosis (n= 1, 3%), Candida palmioleophila (n= 1, 3%) and Candida haemulonis (n= 1, 3%). It is worth mentioning that Candida akabanensis, Candida palmioleophila and Cyberlindnera jadinii have never been described in cases of bovine mastitis. The diversity of yeasts species suggests that the use of molecular techniques has allowed the realization of more accurate diagnoses, which were not possible from conventional identification methods. For biofilm production capacity, the results showed that both yeasts as Prototheca zopfii have this ability, which is an important virulence factor for the persistence of these microorganisms in the milking environment. The susceptibility profile analysis was performed using the antifungal fluconazole. All isolates of the species P. zopfii were resistant to the drug, whereas for yeasts, three susceptibility patterns were observed: sensitive (n=6; 21.43%), dose-dependent susceptibility (n=21; 75%) and resistant (n=1; 3.57%). In epidemiological analysis for one of the dairy farms included in the study, there was no statistical difference between yeast and Prototheca zopfii in relation to variables considered. In front of these results, it was possible to observe the relevance of these micro-organisms in cases of bovine mastitis and the importance of studies for the identification of pathogens and solutions for the control of microorganisms in the milking environment, considering measures to prevent and treatment.