PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Bier D., Tutija J.F., Pasquatti T.N., Oliveira T.L., Araújo F.R. & Verbisck N.V. 2017. [MALDI–TOF mass spectrometry identification of Salmonella spp. and Escherichia coli isolated from bovine carcasses.] Identificação por espectrometria de massa MALDI-TOF de Salmonella spp. e Escherichia coli isolados de carcaças bovinas. Pesquisa Veterinária Brasileira 37(12):1373-1379. Setor de Sanidade Animal, Embrapa Gado de Corte, Av. Rádio Maia 830, Zona Rural, Campo Grande, MS 79106-550, Brazil. E-mail: newton.verbisck@embrapa.br The aim of this study was to introduce matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry to improve the traditional microbiological method for the detection of Salmonella spp. and Escherichia coli in beef carcasses. Two hundred seventy samples from 90 beef carcasses were evaluated. The methodologies described in ISO 6579:2002 and in the Compendium of Methods for the Microbiological Examination of Foods were used for Salmonella spp. and E. coli isolation, respectively. MALDI-TOF analysis were performed on tryptone soya broth suspension isolates or directly from nutrient agar colonies, from the positive, inconclusive or negative biochemically tested samples for Salmonella and E. coli. Mass profiles were acquired on an Autoflex III SmartBeam MALDI-TOF mass spectrometer and the raw spectra were processed using the MALDI Biotyper software (Bruker Daltonics). According to the preliminary identification based on colony morphology and the biochemical reactions, seven isolates were positive for Salmonella spp. Through MALDI Biotyper these seven isolates were also classified as belonging to the genus Salmonella and further identified as S. enterica. Four isolates showing unusual phenotypic characteristics and inconclusive results in biochemical tests for Salmonella were identified as belonging to Citrobacter and Proteus genera after MALDI analysis. Regarding Escherichia coli, 37 were positive for species biochemical testing which MALDI Biotyper confirmed. MALDI-TOF methodology allowed rapid Salmonella spp. and E. coli identity confirmation and may be used to detect these microrganisms within bacterial isolates from beef carcasses.

• Salmonella spp. Escherichia coli enterobacteria enterobactérias

Abstract in Portuguese:

RESUMO.- Bier D., Tutija J.F., Pasquatti T.N., Oliveira T.L., Araújo F.R. & Verbisck N.V. 2017. [MALDI–TOF mass spectrometry identification of Salmonella spp. and Escherichia coli isolated from bovine carcasses.] Identificação por espectrometria de massa MALDI-TOF de Salmonella spp. e Escherichia coli isolados de carcaças bovinas. Pesquisa Veterinária Brasileira 37(12):1373-1379. Setor de Sanidade Animal, Embrapa Gado de Corte, Av. Rádio Maia 830, Zona Rural, Campo Grande, MS 79106-550, Brazil. E-mail: newton.verbisck@embrapa.br O objetivo deste trabalho foi introduzir a técnica de espectrometria de massa com fonte de ionização e dessorção a laser assistida por matriz e analisador de tempo-de-voo (MALDI-TOF) para incrementar o método tradicional microbiológico na detecção de Salmonella spp. e Escherichia coli em carcaças bovinas. Foram avaliadas 270 amostras de 90 carcaças de bovinos. Para isolamento de Salmonella spp. e E. coli, foram utilizadas, respectivamente, as metodologias descritas na ISO 6579:2002 e no Compendium of Methods for the Microbiological Examination of Foods. As análises por MALDI-TOF foram realizadas a partir de isolados cultivados em ágar nutriente ou em caldo triptona de soja, provenientes das amostras com características bioquímicas positivas (n=7), inconclusivas (n=4) e negativas (n=85) para Salmonella spp. e bioquímicas positivas (n=37) e negativas (n=85) para E. coli. Os perfis de massas foram adquiridos com o espectrômetro de massas MALDI-TOF Autoflex III SmartBeam e os espectros brutos foram processados usando o programa MALDI Biotyper (Bruker Daltonics). De acordo com a identificação preliminar, com base na morfologia das colônias e nas reações bioquímicas, sete isolados foram considerados positivos para Salmonella spp. Através do MALDI Biotyper, esses sete isolados foram classificados como pertencentes ao gênero Salmonella e, além disso, identificados como S. enterica. Quatro isolados que apresentaram características fenotípicas não usuais e resultados inconclusivos nos testes bioquímicos para Salmonella foram identificados como pertencentes aos gêneros Citrobacter e Proteus após análise por MALDI. Para E. coli, 37 amostras foram positivas pelos testes bioquímicos da espécie, o que foi confirmado por MALDI Biotyper. A metodologia MALDI-TOF permitiu a rápida confirmação da identidade de Salmonella spp. e E. coli, podendo ser utilizada para detecção desses microrganismos em isolados bacterianos de carcaças bovinas.

Abstract in English:

ABSTRACT.- Curci V.C.M., Dutra I.S., Döbereiner J. & Lucas Junior J. 2007. [The effect of composting cattle carcasses on botulinum spores and toxin content.] Pré-compostagem de cadáveres de bovinos acometidos pelo botulismo. Pesquisa Veterinária Brasileira 27(4):157-161. Unidade de Pesquisa e Desenvolvimento Tecnológico do Agronegócio, APTA Regional Extremo Oeste, Laboratório de Sanidade Animal, Av. Alcides Fagundes Chagas 122, Araçatuba, SP 15055-240, Brazil. E-mail: vlmcursi@aptaregional.sp.gov.br Five carcasses of cattle that died from botulism were composted in individual isolated beds with the purpose of monitoring the effect on spores of Clostridium botulinum and of botulinum toxin. The diagnosis of botulinum poisoning was based on clinical and pathological, epidemic and/or laboratorial characteristics. Of the five bovines with clinical signs of chronic botulism, three were affected by the type D toxin, one by the CD complex, and one was negative for toxin and spores of C. botulinum in the viscera using a mouse bioassay. The composting process was carried out in beds with carcasses cut up and mixed with sawdust as a carbon source. They were kept anaerobic under a plastic sheet for 50 days. The temperature of the beds was monitored during the period and oscillated from 40.5 to 52.4°C. After this time, soft tissue had complete decomposed with a significant loss of weight (26.5-44.5%). The remaining bones no longer contained spores or botulinum toxin in the 5 samples taken from each carcass. Only 2 of the 200 samples of homogenized remaining (40 for each carcass) contained spores of C. botulinum type C. All samples were negative for botulinum toxin using the mouse bioassay. Composting carcasses of cattle that died from botulism eliminated botulinum spores and toxin from the remains.

• Composting bovine carcasses botulism botulinum toxin C and D Clostridium botu-linum

Abstract in Portuguese:

ABSTRACT.- Curci V.C.M., Dutra I.S., Döbereiner J. & Lucas Junior J. 2007. [The effect of composting cattle carcasses on botulinum spores and toxin content.] Pré-compostagem de cadáveres de bovinos acometidos pelo botulismo. Pesquisa Veterinária Brasileira 27(4):157-161. Unidade de Pesquisa e Desenvolvimento Tecnológico do Agronegócio, APTA Regional Extremo Oeste, Laboratório de Sanidade Animal, Av. Alcides Fagundes Chagas 122, Araçatuba, SP 15055-240, Brazil. E-mail: vlmcursi@aptaregional.sp.gov.br Five carcasses of cattle that died from botulism were composted in individual isolated beds with the purpose of monitoring the effect on spores of Clostridium botulinum and of botulinum toxin. The diagnosis of botulinum poisoning was based on clinical and pathological, epidemic and/or laboratorial characteristics. Of the five bovines with clinical signs of chronic botulism, three were affected by the type D toxin, one by the CD complex, and one was negative for toxin and spores of C. botulinum in the viscera using a mouse bioassay. The composting process was carried out in beds with carcasses cut up and mixed with sawdust as a carbon source. They were kept anaerobic under a plastic sheet for 50 days. The temperature of the beds was monitored during the period and oscillated from 40.5 to 52.4°C. After this time, soft tissue had complete decomposed with a significant loss of weight (26.5-44.5%). The remaining bones no longer contained spores or botulinum toxin in the 5 samples taken from each carcass. Only 2 of the 200 samples of homogenized remaining (40 for each carcass) contained spores of C. botulinum type C. All samples were negative for botulinum toxin using the mouse bioassay. Composting carcasses of cattle that died from botulism eliminated botulinum spores and toxin from the remains.