[1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, BR-05508900 Sao Paulo, Brazil
[2] Univ Fed Santa Maria, Dept Vet Prevent Med, BR-97105900 Santa Maria, RS, Brazil
[3] Univ Sao Paulo, Fac Zootecn & Engn Alimentos, BR-13630970 Pirassununga, SP, Brazil