Avalia??o do papel de Stomoxys calcitrans (Linnaeus, 1758) na veicula??o de Escherichia coli causadora de mastite bovina e outros agentes bacterianos.

Autor: Castro, Bruno Gomes de
Jazyk: portugalština
Rok vydání: 2008
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFRRJUniversidade Federal Rural do Rio de JaneiroUFRRJ.
Druh dokumentu: Doctoral Thesis
Popis: Made available in DSpace on 2016-04-28T20:16:26Z (GMT). No. of bitstreams: 1 2008- Bruno Gomes de Castro01.pdf: 514321 bytes, checksum: bd4fc9254117e81edaedf3e2ba5305e2 (MD5) Previous issue date: 2008-04-01
Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro
This study had the objective of evaluating the capacity of Stomoxys calcitrans fly to vehicular bacterial agents causing bovine mastitis. Just as evaluate the enterobacterian microbiota on the external surface, mouth parts and abdominal digestive tract of the stable fly. And also realize a survey of the bacterial microbiota of the cases of bovine mastitis on the visited properties. There were taken mastitis milk samples and 20 specimens of stable flies on 10 visited properties in the municipatility of Barra Mansa and Resende, Rio de Janeiro State. The collected milk was submitted to bacterial isolation in the laboratory of Bacteriology UFRRJ. Samples were subcultures on MacConkey (MC) agar, Brain-Heart Infusion agar (BHI) and Manitol-Phenol Red agar. The flies were individually washed in BHI broth, sterilized and had its mouth parts and abdominal intestinal content dissected under stereoscope microscope. These structures were macerated in BHI broth and, after 24 hours at 37 ?C, subcultured at MC agar, Agar Eosin Methilen Blue (EMB) and enriched in Sodium Tetrathionate Broth after incubation, and were subcultured in Salmonella-Shigella agar. After this stage, each isolated colony was observed for differences in morphology as size and pigment production characteristics to be identified through biochemical specific tests. It was also realized an antimicrobial resistance test to verify to which antibiotics the isolated bacteria were sensible. When were coincidences between the enterobacterian species in the milk and on the flies evaluated segments, was realized a Random Amplified Polymorphic DNA (RAPD-PCR) as an instrument of evaluating the genetic diversity and the eletrophoretic profile similarity the bacterial subpopulations. In agreement with the obtained results, was verified that the mastitis milk had as etiological agents specially the species Staphylococcus aureus, coagulasenegative staphylococci and Escherichia coli. The antimicrobials with less resistance rate were Amoxilin-Clavulanic Acid and Norfloxacin. Regarding to the enterobacterian microbiota verified on S. calcitrans segments, Escherichia coli, Enterobacter agglomerans, Enterobacter cloacae e Salmonella spp were the most prevalent bacteria. The segment with the higher number of isolations was the external surface, with 73 (45.91%) distinct colonies isolated. The mouth parts had 46 (28.93%) colonies and the abdominal digestive tract 40 (25.16%) isolated colonies. The eletrophoretic profile similarity happened just on E. coli subpopulations on milk samples and S. calcitrans segments of the same property. This way, was possible to observe that the flies do not act as a vehicle of any bovine mastitis causative E. coli. Regarding to the identified E. coli, was verified that 13.79% were Shiga Toxin-Producing, and the genes stx1, stx2 and eae were identified. On the present study, was verified that this fly has the capacity to act as vehicle to enterobacterian, on its external surface as well as inside its body. The stable fly control may contribute to the improvement on animal productivity and sanity.
Este estudo teve o objetivo de avaliar a capacidade da mosca Stomoxys calcitrans em veicular agentes bacterianos causadores de mastite bacteriana bovina, bem como avaliar a microbiota enterobacteriana na superf?cie externa, aparelho bucal e trato digest?rio abdominal da mosca dos est?bulos; e fazer um levantamento da microbiota bacteriana nos casos de mastite bovina das propriedades visitadas. Foram coletadas amostras de leite com mastite e 20 esp?cimes da mosca dos est?bulos em 10 propriedades visitadas nos munic?pios de Barra Mansa e Resende, Estado do Rio de Janeiro. No Laborat?rio de Bacteriologia da UFRRJ foi realizado o isolamento bacteriano do leite coletado em Agar MacConkey (MC), Agar Infuso C?rebro Cora??o (BHI) e Manitol Vermelho de Fenol. As moscas foram lavadas individualmente em Caldo BHI, esterilizadas e, sob a luz de um microsc?pio estereosc?pio, tinham seu aparelho bucal e conte?do intestinal abdominal dissecado. Estas estruturas foram maceradas em Caldo BHI e ap?s 24 horas a 37 ?C repicados em Agar MC, Agar Eosina Azul de Metileno (EMB) e enriquecidos em Caldo Tetrationato de S?dio que ap?s incuba??o, era repicado em Agar Salmonella-Shigella. Ap?s esta etapa, cada col?nia isolada era avaliada quanto ?s suas caracter?sticas morfo-tintoriais para serem identificadas atrav?s de testes bioqu?micos espec?ficos. Tamb?m foi realizado o teste de resist?ncia antimicrobiana, com a finalidade de se verificar, as quais antibi?ticos as bact?rias isoladas foram sens?veis. Quando havia coincid?ncia de esp?cies enterobacterianas no leite e nos segmentos avaliados das moscas, se realizava a t?cnica de an?lise do polimorfismo dos segmentos de DNA obtidos por amplifica??o rand?mica (RAPD-PCR) como instrumento de avalia??o da diversidade gen?tica e das rela??es de clonalidade entre estas subpopula??es bacterianas. De acordo com os resultados obtidos, foi verificado que o leite com mastite, teve como principais agentes etiol?gicos as esp?cies Staphylococcus aureus, Estafilococos Coagulase Negativa (ECN) e Escherichia coli. Os antimicrobianos com menor taxa de resist?ncia foram Amoxicilina/?cido Clavul?nico e Norfloxacina. Com rela??o ? microbiota enterobacteriana verificada nos segmentos de S. calcitrans, foi observado que Escherichia coli, Enterobacter agglomerans, Enterobacter cloacae e Salmonella spp foram as bact?rias mais prevalentes. O segmento com o maior n?mero de isolados foi a superf?cie externa, onde foram isoladas 73 col?nias distintas (45,91%), seguida pelo aparelho bucal com 46 col?nias (28,93%), e pelo trato digest?rio abdominal com 40 col?nias isoladas (25,16%). Houve clonalidade apenas de sub-popula??es de E. coli entre as amostras de leite e de segmentos de S. calcitrans de uma mesma propriedade. Desta forma, foi poss?vel observar que as moscas n?o veiculavam nenhuma E. coli causadora de mastite bovina. No que se refere ?s E. coli identificadas, foi verificado que 13,79% eram Shiga-Toxig?nicos, sendo identificados os genes stx1, stx2 e eaeA. No presente estudo, verificou-se que esta mosca tem a capacidade de veicular enterobact?rias, tanto em sua superf?cie externa como no interior de seu corpo. O controle da mosca dos est?bulos poder? contribuir para melhora na sanidade e produtividade animal.
Databáze: Networked Digital Library of Theses & Dissertations
Externí odkaz: