Detection of Brucella abortus DNA in illegal cheese from São Paulo and Minas Gerais and differentiation of B19 vaccinal strain by means of the polymerase chain reaction (PCR)

Abstract

A total of 192 samples of illegal cheese from different regions of the states of São Paulo and Minas Gerais, Brazil, were analyzed for the isolation and detection of Brucella spp. DNA by means of microbiological culture and polymerase chain reaction (PCR), respectively. Samples that yielded positive results were submitted to the analysis of the occurrence of Brucella abortus (biovars 1, 2 e 4), as well as to the differentiation of DNA in B19 vaccinal strain or Brucella abortus field strain using PCR. Although the microorganism was not isolated from any sample, PCR detected 37 positive samples (19.27%) using genus-specific primers. From these, all (100%) were Brucella abortus. Differentiation of the strain showed that 30/37 samples (81.08%) were vaccinal strain B19 and seven (18.92%) were Brucella abortus field strains. Results showed that diagnostic sensitivity of PCR was greater than that of microbiological culture. The standardization of the reaction for the differentiation of vaccinal and field strains enabled the analysis of all samples positive for Brucella abortus. It is, therefore, a reliable method, also applicable to natural infections caused by the microrganism.

Detect ion of Prevence and contamination level of B rucella spp. in local cheese produced in Afyonkarahisar, Turkey

“…During 1983During -1984 in Greece, 23 cases of brucellosis were associated with consumption of a variety of fresh home made cheeses (Sharp, 1987). Sabbaghian (1975) (Miyashiro et al, 2007). Haddad et al, 1993 reported that, 85 cheese samples were examined, 8 of which were positive for B. abortus.…”

Avaliação genética das vacinas contra a brucelose bovina comercializadas no Brasil

“…Todas as amostras B19 comercializadas no Brasil e testadas neste estudo mostraram-se com o padrão de deleção no gene ery, corroborando com os resultados descritos por Miyashiro et al (2007), que observaram o mesmo perϐil de fragmento quando diferenciaram as amostras de campo das amostras vacinais B19. Porém, estudos feitos na Índia constataram que as amostras vacinais HR 19 e IVRI, obtidas de coleções de culturas do tipo americanas (ATCC #27565), utilizadas para a fabricação das amostras comercializadas neste país, não apresentaram a deleção do gene ery.…”

“…O par de oligonucleotídeos VIRB5 foi desenhado para conϐirmação do gênero Brucella. A inserção do elemento IS711 foi utilizada para genotipagem das amostras vacinais RB51 (Vemulapalli et al 1999) e o gene ery, essencial para o catabolismo do eritritol, foi utilizado para a avaliação dos genóti-pos das amostras vacinais B19 (Miyashiro et al 2007). Os oligonucleotídeos utilizados neste estudo estão listados no Quadro 1.…”

“…As espécies pertencentes ao gênero Brucella utilizam preferencialmente a via metabólica do eritritol (álcool polihídrico), promovendo o crescimento das amostras em meios ricos na presença deste álcool. A amostra vacinal atenuada B19 sofreu uma deleção natural de 702 pares de bases (pb) no gene ery, ocorrendo a inibição do crescimento dessa amostra na presença desse álcool (Sangari et al 2000, Miyashiro et al 2007). Entretanto, foi observado que amostras da vacina B19, comercializadas na Índia, não possuem essa deleção, porém apresentaram redução da virulência em camundongos BALB/c (Mukherjee et al 2005).…”

Bovine brucellosis: epidemiological situation in Brazil and disease control initiatives

“…Risk groups include veterinary staff (VILLARROEL et al, 2000), farmers and rural workers (SANTOS-NETO et al, 1999;FERREIRA et al, 2002;DRAGOSAVAC et al, 2007;MELO et al, 2007), and slaughterhouse workers (RAMOS et al, 2008), and since it can be excreted in the milk and survive for long periods in both milk and contaminated products (LANGONI et al, 2000;MIYASHIRO et al, 2007), the disease can be conveyed to consumers.…”