Food and Nutrition Sciences, 2014, 5, 1496-1505 Published Online August 2014 in SciRes. http://www.scirp.org/journal/fns http://dx.doi.org/10.4236/fns.2014.515162 How to cite this paper: Santos, V.M., et al. (2014) Virulence Factor Profile of Staphylococcus aureus Isolated from Bovine Milk from Brazil. Food and Nutrition Sciences, 5, 1496-1505. http://dx.doi.org/10.4236/fns.2014.515162 Virulence Factor Profile of Staphylococcus aureus Isolated from Bovine Milk from Brazil Verena M. Santos 1 , Hellen B. Martins 1 , Izadora S. Rezende 1 , Maysa S. Barbosa 1 , Ewerton F. Andrade 1 , Simone G. Souza 1 , Guilherme B. Campos 1 , Pollianna S. Oliveira 1 , Daniel S. Sousa 1 , Danilo C. C. Da Silva 1 , Aline T. Amorim 1 , Jorge Timenetsky 2 , Mariluze P. Cruz 1 , Regiane Yatsuda 1 , Lucas M. Marques 1* 1 Instituto Multidisciplinar em Saúde, Núcleo de Tecnologia em Saúde, Universidade Federal da Bahia, Vitoria da Conquista, Brazil 2 Instituto de Ciências Biomédicas, Departamento de Microbiologia, Universidade de São Paulo, São Paulo, Brazil Email: * lucasm@ufba.br Received 25 May 2014; revised 1 July 2014; accepted 11 July 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract This study investigates the biofilm formation, presence and distribution of virulence genes and the capacity to induce an inflammatory response in strains of Staphylococcus aureus isolated from milk samples in Bahia, Brazil. A total of 132 samples of raw milk were collected from four dairy farms (designated A to D) located in southwestern Bahia, in the municipality of Vitória da Con- quista, from October/2009 to September/2010. After processing of the samples, 94 (71.2%) S. au- reus isolates were obtained. These strains were subjected to the antibiogram method MIC (Mini- mum Inhibitory Concentration). As for the pathogenicity, tests were performed in vitro biofilm formation induced by glucose. Moreover, we performed PCR for their virulence genes: sea (ente- rotoxin A), seb (B), sec (C), pvl (Panton-Valentine Leukocidin), clfA (Clumping Factor A) and spa (protein A) and analysis of cytokine induction in the inflammatory response of J774 macrophages by exocellular lipoteichoic acid. No isolates were resistant to oxacillin and vancomycin. In biofilm production, 5.31% (5/94) isolates did not produce biofilm, 5.31% (5/94) of the samples were poor producers, 15.96% (15/94) strains were moderate producers, 18.09% (17/94) were produc- ers and 55.32% (55/94) of isolates were strong biofilm producers. One (1.06%) isolate expressed the seb gene, one (1.06%) sec, 18 (19.2%) cflA and 44 (46.8%) had spa. There was no expression of sea and pvl between isolates analyzed. The analysis of cytokine induction in the inflammatory re- sponse did not show statistical difference in the levels of IL-6, TNF-α and IL-10 induction. However, there was statistical difference in IL-1 induction between isolates from different farms. Thus, it * Corresponding author.