Bovine mastitis associated with Prototheca blaschkeae

Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Largo Prof. Abel Salazar, 2, 4099-003 Porto, Portugal; Unidade Multidisciplinar de Investigação Biomédica (UMIB), Universidade do Porto, Largo Professor Abel Salazar, 2, 4099-003 Porto, Portugal; Department für Biologie – Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, D-91058 Erlangen, Germany; Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO-ICETA), Universidade do Porto, Rua Padre Armando Quintas 4485-661 Vairão, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal

^* To whom correspondence should be addressed. Email: saramarques{at}mail.icav.up.pt.

	Abstract

Bovine mastitis is an important and complex disease responsible for economic losses in the dairy industry. Biotype II strains of the green alga Prototheca zopfii can be involved, most often resulting in chronic mastitis of difficult treatment associated with reduced milk production. This type of infection is rare, but the number of reported cases is increasing worldwide. In order to determine the kind of species involved in mastitis by Prototheca in the Northwest of Portugal, 41 Prototheca isolates were genetically characterized. The algae are part of Prototheca isolates that were collected during a 6 years period, isolated from the milk of 41 dairy cows, in a total of 22 herds, with a history of increasing somatic cell counts, mild clinical signs of udder infection and unsuccessful response to the usual therapy. PCR amplification of the 18S rDNA, amplified rDNA restriction analysis, and phylogenetic analyses of the 18S rDNA sequences were performed. Thirty-seven isolates were identified as P. zopfii var. hydrocarbonea and four as P. blaschkeae. These data suggest a high incidence of P. zopfii var. hydrocarbonea mastitis in the region, and demonstrate for the first time the involvement of P. blaschkeae with bovine mammary gland infections.