Thesis (Ph.D.)--Murdoch University, 2006. / Thesis submitted to the Division of Health Sciences.

Orientador: Alexandre Secorun Borges / Banca: Marcio Garcia Ribeiro / Banca: Carla Bargi Belli / Resumo: A diarreia é um grave problema em potros até seis meses de vida, acarretando em prejuízos na equideocultura. Sendo assim os objetivos desta pesquisa foram realizar o estudo clínico e a identificação dos principais enteropatógenos e fatores de virulência, responsáveis pela diarreia em potros. Foram avaliados 56 potros com diarreia (GD) e 60 sem diarreia (GC) até 90 dias de vida. Foram realizados hemogasometria e hemograma dos animais do GD. Amostras fecais dos potros do GD e GC foram utilizadas para a identificação dos enteropatógenos. As principais alterações clínicas nos animais GD foram aumento da peristalse e da frequência de defecação (100,0%) e desidratação (67,8%). A hiperfibrinogenemia (26,8%), leucocitose (12,5%), linfocitose (37,5%) e neutrofilia (17,8), acidose metabólica (16%) e diminuição de bicarbonato (16%) foram os principais achados hematológicos. Ao menos um dos enteropatógenos pesquisados foi detectado no GD (50/56) e GC (48/60). Em 32% (16/50) das amostras positivas foi identificado um único enteropatógeno, enquanto que dois ou mais enteropatógenos foram detectados em 68% (34/50) das amostras. E. coli apresentou a maior frequência nos isolamentos dos potros com diarreia (62,5%), seguida da Salmonella spp. (25%); Strongyloides (25%); estrongilídeos (10,7%); Clostridium perfringens (10,7%); Rhodococcus equi (7,1%); Cryptosporidium spp. (5,4%); Clostridium difficile (1,8%); coronavírus (1,8%); Giardia sp. (1,8%). Conclui-se que a identificação dos animais desidratados e com graves alterações hidroeletrolíticas, bem como a necessidade de se detectar os agentes etiológicos e seus fatores de virulência, são importantes para direcionar o médico veterinário a definir medidas de controle e terapêutica adequados / Abstract: Diarrhea is a serious problem in foals up to six months old, resulting in losses in equine business. The aims of this research were to perform the clinical study and the identification of main pathogens and virulence factors responsible for diarrhea in foals. A total of 56 foals with diarrhea (DG) and and 60 without diarrhea (CG) up to 90 days old were evaluated. Fecal samples of a (DG) and 60 without diarrhea (GC) up to 90 days old were evaluated. Hemogram and hemogasometry were performed in the animals of DG. Fecal samples of DG and GC were used to identify the enteropathogens. The main clinical findings in animals of GD were increased peristalsis and defecation frequency (100,%) and dehydration (67.8%). Hyperfibrinogenemia (26.8%), leukocytosis (12.5%), lymphocytosis (37.5%) and neutrophilia (17.8%), metabolic acidosis (16%) and decreased bicarbonate (16%) were the main hematologic findings. At least one of the enteropathogens studied was detected in DG (50/56) and in CG (48/60). In 32% (16/50) of positive samples was identified a single enteropathogen, while two or more enteropathogens were detected in 68% (34/50) of samples. E. coli showed the highest frequency in the isolations of foals with diarrhea (62.5%), followed by Salmonella spp. (25%); Strongyloides (25%); Strongyles (10.7%); C. perfringens (10.7%), Rhodococcus equi (7.1%); Cryptosporidium spp. (5.4%); C. difficile (1.8%), coronavirus (1.8), Giardia sp. (1.8%). In conclusion the identification of dehydrated animals and animals with severe electrolyte alterations as well as the need to detect the etiologic agents and their virulence factors are important to conduct the veterinarian to define control measures and appropriate therapy / Mestre

Made available in DSpace on 2014-08-13T14:50:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-01Bitstream added on 2014-08-13T18:00:44Z : No. of bitstreams: 1 000754734_20150701.pdf: 231621 bytes, checksum: 4c2f97d9c6c55f4efc6859a27924d8f8 (MD5) Bitstreams deleted on 2015-07-01T11:47:20Z: 000754734_20150701.pdf,. Added 1 bitstream(s) on 2015-07-01T11:48:06Z : No. of bitstreams: 1 000754734.pdf: 1149581 bytes, checksum: 00a6992568f37a07b9de0817318cc468 (MD5) / A diarreia é um grave problema em potros até seis meses de vida, acarretando em prejuízos na equideocultura. Sendo assim os objetivos desta pesquisa foram realizar o estudo clínico e a identificação dos principais enteropatógenos e fatores de virulência, responsáveis pela diarreia em potros. Foram avaliados 56 potros com diarreia (GD) e 60 sem diarreia (GC) até 90 dias de vida. Foram realizados hemogasometria e hemograma dos animais do GD. Amostras fecais dos potros do GD e GC foram utilizadas para a identificação dos enteropatógenos. As principais alterações clínicas nos animais GD foram aumento da peristalse e da frequência de defecação (100,0%) e desidratação (67,8%). A hiperfibrinogenemia (26,8%), leucocitose (12,5%), linfocitose (37,5%) e neutrofilia (17,8), acidose metabólica (16%) e diminuição de bicarbonato (16%) foram os principais achados hematológicos. Ao menos um dos enteropatógenos pesquisados foi detectado no GD (50/56) e GC (48/60). Em 32% (16/50) das amostras positivas foi identificado um único enteropatógeno, enquanto que dois ou mais enteropatógenos foram detectados em 68% (34/50) das amostras. E. coli apresentou a maior frequência nos isolamentos dos potros com diarreia (62,5%), seguida da Salmonella spp. (25%); Strongyloides (25%); estrongilídeos (10,7%); Clostridium perfringens (10,7%); Rhodococcus equi (7,1%); Cryptosporidium spp. (5,4%); Clostridium difficile (1,8%); coronavírus (1,8%); Giardia sp. (1,8%). Conclui-se que a identificação dos animais desidratados e com graves alterações hidroeletrolíticas, bem como a necessidade de se detectar os agentes etiológicos e seus fatores de virulência, são importantes para direcionar o médico veterinário a definir medidas de controle e terapêutica adequados / Diarrhea is a serious problem in foals up to six months old, resulting in losses in equine business. The aims of this research were to perform the clinical study and the identification of main pathogens and virulence factors responsible for diarrhea in foals. A total of 56 foals with diarrhea (DG) and and 60 without diarrhea (CG) up to 90 days old were evaluated. Fecal samples of a (DG) and 60 without diarrhea (GC) up to 90 days old were evaluated. Hemogram and hemogasometry were performed in the animals of DG. Fecal samples of DG and GC were used to identify the enteropathogens. The main clinical findings in animals of GD were increased peristalsis and defecation frequency (100,%) and dehydration (67.8%). Hyperfibrinogenemia (26.8%), leukocytosis (12.5%), lymphocytosis (37.5%) and neutrophilia (17.8%), metabolic acidosis (16%) and decreased bicarbonate (16%) were the main hematologic findings. At least one of the enteropathogens studied was detected in DG (50/56) and in CG (48/60). In 32% (16/50) of positive samples was identified a single enteropathogen, while two or more enteropathogens were detected in 68% (34/50) of samples. E. coli showed the highest frequency in the isolations of foals with diarrhea (62.5%), followed by Salmonella spp. (25%); Strongyloides (25%); Strongyles (10.7%); C. perfringens (10.7%), Rhodococcus equi (7.1%); Cryptosporidium spp. (5.4%); C. difficile (1.8%), coronavirus (1.8), Giardia sp. (1.8%). In conclusion the identification of dehydrated animals and animals with severe electrolyte alterations as well as the need to detect the etiologic agents and their virulence factors are important to conduct the veterinarian to define control measures and appropriate therapy

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-10Bitstream added on 2014-06-13T19:43:50Z : No. of bitstreams: 1 muniz_mhb_dr_botfmvz.pdf: 171267 bytes, checksum: e98902db756ea075489458c1c37abacb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Foram utilizados 54 leitões de genética comercial, desmamados com idade média de 24 dias e peso médio de 7,35 kg, num delineamento experimental de blocos ao acaso com dois tratamentos, nove repetições e três animais por parcela. Os tratamentos foram rações suplementadas com minerais de fontes orgânicas e inorgânicas (Cu, Zn, Fe, Mn e Se) nas fases pré- inicial, inicial I e inicial II. Foram avaliados os dados médios de consumo diário de ração, ganho diário de peso e conversão alimentar nos períodos de 24 a 28, 24 a 50 e 24 a 57 dias de idade, bem como a incidência de diarréia nos primeiros 14 dias do período experimental. Após a última pesagem foi coletada uma amostra de sangue de cada animal para avaliação dos parâmetros hematológicos e em seguida os leitões foram abatidos para avaliação da deposição de minerais em tecidos e órgãos. As fontes orgânicas de minerais nas rações fornecidas dos 24 aos 57 dias de idade dos melhoraram o ganho diário de peso (P = 0,06), a conversão alimentar (P = 0,05) e aumentaram o número de hemácias (P = 0,10), contudo, não influenciaram a incidência de diarréia ou a deposição de minerais no músculo masseter, fígado, coração, baço e rim. Portanto, o uso de suplemento de minerais de fontes orgânicas pode ser recomendado nas rações por ter sido mais eficiente para leitões na fase de creche. / This experiment used 54 piglets from a commercial line, which were weaned at the mean age of 24 days and mean weight of 7.35 kg, in a randomized block design having two treatments, nine replicates and three animals per replicate. The treatments consisted of rations supplemented with either organic or inorganic mineral sources (Cu, Zn, Fe, Mn and Se) during the pre-initial, initial I and initial II phases. Daily ration intake, daily weight gain and feed conversion were computed for three periods: 24-28, 24-50 and 24-57 days of age. Also diarrhea incidence during the first 14 days of the experimental period was evaluated. After the last weighing a blood sample was collected from each animal to evaluate hematological parameters, and then all piglets were slaughtered to evaluate mineral deposition in tissues and organs. The organic mineral sources fed from 24 to 57 days of age improved daily weight gain (P = 0.06) and feed conversion (P = 0.05) and also raised red blood cell count (P = 0.10); however, no evidence was found of any effect on diarrhea incidence or on mineral deposition in the masseter muscle, liver, heart, spleen or kidneys. Therefore, organic mineral supplements can be recommended, as they proved more effective than inorganic sources for nursery piglets.

Orientador: Dirlei Antônio Berto / Coorientador: Alessandro Borges Amorim / Banca: Marcos Livio Panhoza Tse / Banca: Urbano dos Santos Ruiz / Resumo: Dois experimentos (E) foram realizados com o objetivo de avaliar os efeitos do ácido fumárico e de uma mistura de acidificantes a base de formiato de cálcio, lactato de cálcio e ácidos graxos de cadeia média (cáprico e caprílico) nas dietas de leitões, sobre o desempenho e frequência de diarreia (E 1), peso relativo de órgãos, pH, morfometria e microbiota intestinal (E 2). Foram utilizados 192 (E 1) e 24 (E 2) leitões, desmamados com idade média de 21 dias, distribuídos num delineamento experimental de blocos completamente ao acaso com arranjo fatorial 2x2 (ausência e presença de ácido fumárico x ausência e presença da mistura de acidificantes) dos tratamentos, seis repetições de oito e de um animal por parcela, respectivamente, para o E 1 e E 2. No E 1, com duração de 41 dias, os tratamentos foram: Controle: sem produto acidificante + 40ppm de colistina; AF: Presença de ácido fumárico e ausência da mistura de acidificantes; MA: Presença da mistura de acidificante e ausência do ácido fumárico e AF+MA: Presença do ácido fumárico e da mistura de acidificantes. No E 2, com duração de 14 dias, foi utilizada a dieta Pré Inicial I e avaliados os mesmos tratamentos do E 1. Não houve efeito dos tratamentos (P>0,05) no desempenho, incidência de diarreia, pH gastrintestinal e morfometria do duodeno dos leitões, porem, a adição da mistura de acidificantes reduziu (P<0,05) o peso relativo do intestino grosso e a adição do ácido fumárico aumentou o peso relativo do pâncreas e reduziu (P<0,05) a altura de vilosidade do jejuno e a contagem de coliformes totais e Escherichia coli no ceco. A inclusão de ácido fumárico e da mistura de acidificantes nas dietas de leitões desmamados contendo antibiótico melhorador de desempenho não se justifica, contudo, o ácido fumárico exerce ação inibitória sobre a população de coliformes totais e de Escherichia coli / Abstract: Two experiments (E) were conducted to evaluate the effects of fumaric acid and an organic acid blend compound of calcium formate, calcium lactate and medium chain fatty acids (capric and caprylic) in piglets diets on performance and frequency of diarrhea (E 1), relative organ weight, pH, morphometry and intestinal microbiota (E 2). One hundred and ninety two (E 1) and twenty four (E 2) piglets weaned at 21 days, distributed in a randomized block design with a 2x2 factorial arrangement of treatments (absence x presence of fumaric acid and absence x presence of acidifying product), six replications of eight and one pig per pen were used, respectively, for E 1 and E 2. In E 1, lasting 41 days, the treatments were: Control - No acidifying + 40 ppm of colistin sulfate; AF - Presence of fumaric acid and absence of acidifying product; MA - Presence of acidifying product and absence of fumaric acid and AF+MA: presence of fumaric acid and acidifying product. In E 2, lasting 14 days, Pré-Starter I diet was used and assessed the same treatments of E 1. There were no treatment effects (P>.05) in performance, incidence of diarrhea, gastrointestinal pH and morphometry of the duodenum of piglets, however, the addition of organic acid blend reduced (P<.05) the relative weight of the large intestine and the addition of fumaric acid increased the relative weight of the pancreas and decreased (P<.05) the villus height of jejunum and number of total coliforms and Escherichia coli in the cecum. The inclusion of fumaric acid and the organic acid blend in the diets of weaned piglets containing antibiotic is not justified, however, fumaric acid exerts an inhibitory effect on the population of coliforms and Escherichia coli / Mestre

Made available in DSpace on 2014-08-13T14:50:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-05-15Bitstream added on 2014-08-13T18:00:02Z : No. of bitstreams: 1 000767511.pdf: 741976 bytes, checksum: e3ebb473db2a4a3f7ffe085a744f2f0a (MD5) / Dois experimentos (E) foram realizados com o objetivo de avaliar os efeitos do ácido fumárico e de uma mistura de acidificantes a base de formiato de cálcio, lactato de cálcio e ácidos graxos de cadeia média (cáprico e caprílico) nas dietas de leitões, sobre o desempenho e frequência de diarreia (E 1), peso relativo de órgãos, pH, morfometria e microbiota intestinal (E 2). Foram utilizados 192 (E 1) e 24 (E 2) leitões, desmamados com idade média de 21 dias, distribuídos num delineamento experimental de blocos completamente ao acaso com arranjo fatorial 2x2 (ausência e presença de ácido fumárico x ausência e presença da mistura de acidificantes) dos tratamentos, seis repetições de oito e de um animal por parcela, respectivamente, para o E 1 e E 2. No E 1, com duração de 41 dias, os tratamentos foram: Controle: sem produto acidificante + 40ppm de colistina; AF: Presença de ácido fumárico e ausência da mistura de acidificantes; MA: Presença da mistura de acidificante e ausência do ácido fumárico e AF+MA: Presença do ácido fumárico e da mistura de acidificantes. No E 2, com duração de 14 dias, foi utilizada a dieta Pré Inicial I e avaliados os mesmos tratamentos do E 1. Não houve efeito dos tratamentos (P>0,05) no desempenho, incidência de diarreia, pH gastrintestinal e morfometria do duodeno dos leitões, porem, a adição da mistura de acidificantes reduziu (P<0,05) o peso relativo do intestino grosso e a adição do ácido fumárico aumentou o peso relativo do pâncreas e reduziu (P<0,05) a altura de vilosidade do jejuno e a contagem de coliformes totais e Escherichia coli no ceco. A inclusão de ácido fumárico e da mistura de acidificantes nas dietas de leitões desmamados contendo antibiótico melhorador de desempenho não se justifica, contudo, o ácido fumárico exerce ação inibitória sobre a população de coliformes totais e de Escherichia coli / Two experiments (E) were conducted to evaluate the effects of fumaric acid and an organic acid blend compound of calcium formate, calcium lactate and medium chain fatty acids (capric and caprylic) in piglets diets on performance and frequency of diarrhea (E 1), relative organ weight, pH, morphometry and intestinal microbiota (E 2). One hundred and ninety two (E 1) and twenty four (E 2) piglets weaned at 21 days, distributed in a randomized block design with a 2x2 factorial arrangement of treatments (absence x presence of fumaric acid and absence x presence of acidifying product), six replications of eight and one pig per pen were used, respectively, for E 1 and E 2. In E 1, lasting 41 days, the treatments were: Control – No acidifying + 40 ppm of colistin sulfate; AF – Presence of fumaric acid and absence of acidifying product; MA – Presence of acidifying product and absence of fumaric acid and AF+MA: presence of fumaric acid and acidifying product. In E 2, lasting 14 days, Pré-Starter I diet was used and assessed the same treatments of E 1. There were no treatment effects (P>.05) in performance, incidence of diarrhea, gastrointestinal pH and morphometry of the duodenum of piglets, however, the addition of organic acid blend reduced (P<.05) the relative weight of the large intestine and the addition of fumaric acid increased the relative weight of the pancreas and decreased (P<.05) the villus height of jejunum and number of total coliforms and Escherichia coli in the cecum. The inclusion of fumaric acid and the organic acid blend in the diets of weaned piglets containing antibiotic is not justified, however, fumaric acid exerts an inhibitory effect on the population of coliforms and Escherichia coli

Made available in DSpace on 2014-06-11T19:27:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-30Bitstream added on 2014-06-13T20:27:43Z : No. of bitstreams: 1 lucas_tm_me_botfmvz.pdf: 533611 bytes, checksum: 322f330fbea907abb3e0a8da1985add0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A diarreia é causa comum de morbimortalidade em potros neonatos. Os principais agentes causais de origem bacteriana na enterite em potros são: Salmonella spp., Escherichia coli, Clostridium difficile, Clostridium perfringens e Rhodococcus equi. Foram colhidas 80 amostras de fezes de potros com diarreia e 26 sem diarreia, perfazendo 106 animais com idade até três meses de idade, de diferentes raças, provenientes de propriedades do interior do estado de São Paulo. Foi investigado fatores de virulência de Escherichia coli, caracterização dos sorotipos de Salmonella spp., detecção de toxinas de Clostridium difficille e Clostridium perfringens, e perfil de sensibilidade microbiana das linhagens de E. coli e Salmonella spp. Foram isoladas 64 (60,3%) estirpes de Escherichia coli, o gene fimH em 34 (53,9%) linhagens, o gene ag43 em 33 (52,3%) estirpes e o gene papC em seis (9,5%) isolados. Foram isoladas 17 (16,0%) linhagens do gênero Salmonella. Foram identificadas 20 linhagens de Clostridium perfringens,17 positivos para toxina A e três a toxina A beta 2. Duas amostras de fezes foi isolado Clostridium difficile, produtores das toxinas A/B. Infere-se no presente estudo a complexidade etiológica na enterite de potros até três meses de idade, a baixa relação dos fatores de virulência de E. coli pesquisados com linhagens isoladas de animais com diarreia, a relevância em saúde pública dos sorotipos de Salmonella spp. identificados nos potros, o predomínio da toxina A nos isolados de C. perfringens e C. difficile, e a necessidade da adoção de tratamento das enterites com respaldo dos testes de sensibilidade microbiana / Diarrhea is a common cause of morbidity and mortality in neonatal foals. The main causative agents of bacterial of enteritis in foals are: Salmonella spp., Escherichia coli, Clostridium difficile, Clostridium perfringens and Rhodococcus equi. Were collected 80 stool samples from foals with diarrhea and 26 without diarrhea, totaling 106 animals, aged three months old, different races and from properties in the state of São Paulo. Were investigated virulence factors from E. coli, characterization of the serotypes of Salmonella spp., detection of toxins of Clostridium perfringens and Clostridium difficille, and antimicrobial susceptibility to E. coli and Salmonella spp. strains. Were isolated 64 (60.3%) E. coli strains, the detection of the fimH gene in 34 (53.9%) strains, the gene ag43 in 33 (52.3%) strains and gene papC in six (9 , 5%) isolated. We isolated 17 (16.0%) strains of Salmonella. Were identified 20 strains of Clostridium perfringens, 17 detected the toxin A and three the toxin A beta 2. Two stool specimens was isolated Clostridium difficile toxin producer A / B. It is inferred in the present study the complexity enteritis in foals up to three months, the low ratio of virulence factors of E. coli strains isolated from animals with diarrhea, the public health relevance of the serotypes of Salmonella spp. identified in foals, the prevalence of toxin A in isolates of C. perfringens and C. difficile, and the need to adopt the treatment of bacterial enteritis in foals with the backing of microbial sensitivity tests

Orientador: Dirlei Antônio Berto / Banca: Fábio Enrique Lemos Budiño / Banca: Messias Alves da Trindade Neto / Banca: José Roberto Sartori / Banca: Antonio Celso Pezzato / Resumo: Foram utilizados 54 leitões de genética comercial, desmamados com idade média de 24 dias e peso médio de 7,35 kg, num delineamento experimental de blocos ao acaso com dois tratamentos, nove repetições e três animais por parcela. Os tratamentos foram rações suplementadas com minerais de fontes orgânicas e inorgânicas (Cu, Zn, Fe, Mn e Se) nas fases pré- inicial, inicial I e inicial II. Foram avaliados os dados médios de consumo diário de ração, ganho diário de peso e conversão alimentar nos períodos de 24 a 28, 24 a 50 e 24 a 57 dias de idade, bem como a incidência de diarréia nos primeiros 14 dias do período experimental. Após a última pesagem foi coletada uma amostra de sangue de cada animal para avaliação dos parâmetros hematológicos e em seguida os leitões foram abatidos para avaliação da deposição de minerais em tecidos e órgãos. As fontes orgânicas de minerais nas rações fornecidas dos 24 aos 57 dias de idade dos melhoraram o ganho diário de peso (P = 0,06), a conversão alimentar (P = 0,05) e aumentaram o número de hemácias (P = 0,10), contudo, não influenciaram a incidência de diarréia ou a deposição de minerais no músculo masseter, fígado, coração, baço e rim. Portanto, o uso de suplemento de minerais de fontes orgânicas pode ser recomendado nas rações por ter sido mais eficiente para leitões na fase de creche. / Abstract: This experiment used 54 piglets from a commercial line, which were weaned at the mean age of 24 days and mean weight of 7.35 kg, in a randomized block design having two treatments, nine replicates and three animals per replicate. The treatments consisted of rations supplemented with either organic or inorganic mineral sources (Cu, Zn, Fe, Mn and Se) during the pre-initial, initial I and initial II phases. Daily ration intake, daily weight gain and feed conversion were computed for three periods: 24-28, 24-50 and 24-57 days of age. Also diarrhea incidence during the first 14 days of the experimental period was evaluated. After the last weighing a blood sample was collected from each animal to evaluate hematological parameters, and then all piglets were slaughtered to evaluate mineral deposition in tissues and organs. The organic mineral sources fed from 24 to 57 days of age improved daily weight gain (P = 0.06) and feed conversion (P = 0.05) and also raised red blood cell count (P = 0.10); however, no evidence was found of any effect on diarrhea incidence or on mineral deposition in the masseter muscle, liver, heart, spleen or kidneys. Therefore, organic mineral supplements can be recommended, as they proved more effective than inorganic sources for nursery piglets. / Doutor

Orientador: Márcia Garcia Ribeiro / Banca: Antonio Carlos Paes / Banca: Lisiane de Almeida Martins / Resumo: A diarreia é causa comum de morbimortalidade em potros neonatos. Os principais agentes causais de origem bacteriana na enterite em potros são: Salmonella spp., Escherichia coli, Clostridium difficile, Clostridium perfringens e Rhodococcus equi. Foram colhidas 80 amostras de fezes de potros com diarreia e 26 sem diarreia, perfazendo 106 animais com idade até três meses de idade, de diferentes raças, provenientes de propriedades do interior do estado de São Paulo. Foi investigado fatores de virulência de Escherichia coli, caracterização dos sorotipos de Salmonella spp., detecção de toxinas de Clostridium difficille e Clostridium perfringens, e perfil de sensibilidade microbiana das linhagens de E. coli e Salmonella spp. Foram isoladas 64 (60,3%) estirpes de Escherichia coli, o gene fimH em 34 (53,9%) linhagens, o gene ag43 em 33 (52,3%) estirpes e o gene papC em seis (9,5%) isolados. Foram isoladas 17 (16,0%) linhagens do gênero Salmonella. Foram identificadas 20 linhagens de Clostridium perfringens,17 positivos para toxina A e três a toxina A beta 2. Duas amostras de fezes foi isolado Clostridium difficile, produtores das toxinas A/B. Infere-se no presente estudo a complexidade etiológica na enterite de potros até três meses de idade, a baixa relação dos fatores de virulência de E. coli pesquisados com linhagens isoladas de animais com diarreia, a relevância em saúde pública dos sorotipos de Salmonella spp. identificados nos potros, o predomínio da toxina A nos isolados de C. perfringens e C. difficile, e a necessidade da adoção de tratamento das enterites com respaldo dos testes de sensibilidade microbiana / Abstract: Diarrhea is a common cause of morbidity and mortality in neonatal foals. The main causative agents of bacterial of enteritis in foals are: Salmonella spp., Escherichia coli, Clostridium difficile, Clostridium perfringens and Rhodococcus equi. Were collected 80 stool samples from foals with diarrhea and 26 without diarrhea, totaling 106 animals, aged three months old, different races and from properties in the state of São Paulo. Were investigated virulence factors from E. coli, characterization of the serotypes of Salmonella spp., detection of toxins of Clostridium perfringens and Clostridium difficille, and antimicrobial susceptibility to E. coli and Salmonella spp. strains. Were isolated 64 (60.3%) E. coli strains, the detection of the fimH gene in 34 (53.9%) strains, the gene ag43 in 33 (52.3%) strains and gene papC in six (9 , 5%) isolated. We isolated 17 (16.0%) strains of Salmonella. Were identified 20 strains of Clostridium perfringens, 17 detected the toxin A and three the toxin A beta 2. Two stool specimens was isolated Clostridium difficile toxin producer A / B. It is inferred in the present study the complexity enteritis in foals up to three months, the low ratio of virulence factors of E. coli strains isolated from animals with diarrhea, the public health relevance of the serotypes of Salmonella spp. identified in foals, the prevalence of toxin A in isolates of C. perfringens and C. difficile, and the need to adopt the treatment of bacterial enteritis in foals with the backing of microbial sensitivity tests / Mestre

MSc (Microbiology) / Department of Microbiology / Background: Diarrheal diseases constitute an important problem among children but also among HIV positive patients particularly in developing countries such as South Africa. Cryptosporidium infect humans and has been shown to be an important cause of infection among different types of animals. Because of its small size, Cryptosporidium can easily go through the water purification system and can easily become a cause of an epidemic. Previous studies have shown that Cryptosporidium is an important cause of diarrhea in Limpopo Province. However, very few studies have been conducted on the genetic diversity of these organisms in the region. Therefore, the aim of this study was to detect and identify the genetic diversity of Cryptosporidium species from humans and animals in Giyani situated in the northern part of South Africa and Pretoria situated in the central part of the country. Methodology: A total of 560 samples were collected from human and animals and were all screened by microscopy using modified Ziehl-Neelsen staining technique. All the samples were tested by Enzyme-Linked Immunosorbent Assay (ELISA) using the Cryptosporidium II kits from Techlab, Virginia, USA. Positive samples from microscopy and ELISA were examined by different PCR protocols including conventional PCR for amplification of Cryptosporidium oocyst wall protein (COWP) region; Real-time PCR employing SYBR Green detection format for amplification of 18S rRNA region; Real-time PCR employing Hydrolysis probes detection format for amplification of SSU rRNA region; Real-time PCR specific for amplification of C. hominis region and C. parvum region. Positive samples from real-time PCR that gave clear bands on gel electrophoresis were sent for sequencing. The sequences were analysed using Staden package software to edit the nucleotides, Bioedit and MEGA6 software were used to align sequences and draw phylogenetic trees. The SPSS software was used for statistical analysis. xiii Results: The overall prevalence of Cryptosporidium as detected by ELISA method from the samples collected from humans was 41.2% (239/580). The prevalence was higher from the rural area 73.0% (159/218) compared to the urban area 22.1% (80/362) and the difference was statistically significant (χ2 = 145.1; p = 0.0001). Due to the limited amount of samples, only 134 ELISA-positive samples were tested using real-time PCR. Of these samples, 35.8% (48/134) tested positive. Of 48 real-time positive samples 25 were successfully sequenced and two different species (C. hominis and C. muris) were identified. Of all the sequences obtained, one (4.0%) was C. muris and 20 (80%) were C. hominis isolated from rural area, whereas 16.0% (4/25) were also C. hominis isolated from samples obtained from urban area. Cryptosporidium was not associated with diarrhea in the present study. A total of 85 samples were collected from animals (52 from cattle and 33 from goats) and of these 4 (4.7%) were positive by microscopy and ELISA. All these samples were non diarrheal. Conventional PCR also detected a similar number. Of these 4 positive samples, 1 was from a male goat, while the 3 others were obtained from female adult goats. Real-time PCR detected 56.5% (48/85) positive samples. Only 12 of the 85 animal samples were diarrheal and of these 4 were positive for Cryptosporidium. The prevalence of Cryptosporidium infection was higher 68.4% (13/19) in male animals compared to female animals 53.0% (35/66). The prevalence rates in cattle and goats were 55.8% (29/52) and 60.6% (20/33) respectively. Of 48 real-time positive samples from animals, 12 (25.0%) were successfully sequenced and two species (C. parvum and C. andersoni) were identified. Of these 6 were from cattle and the other 6 were from goats. Out of the 12 samples 10 (83%) were C. parvum while 2 (17%) were C. andersoni. Of the two C. andersoni, one was from a goat and one was from a cow. Of the 10 C. parvum, 5 were from goats and 5 were from cattle. xiv In conclusion, microscopy remains the low sensitive tool for the detection of Cryptosporidium while real time PCR appeared to be far much more sensitive by detecting more samples than all the three other methods combined. Closer to the real time PCR was ELISA that detected also more samples compared to conventional PCR and microscopy. The present study identified C. muris from humans’ samples in our area for the first time. However, C. hominis remains the dominant species that infects humans in our area. Cryptosporidium species was mostly found in samples from asymptomatic individuals. In animals, C. parvum was the most commonly isolated organism while C. andersoni was identified in our region for the first time as well and occurred in both goats and cattle. Populations in the affected areas need to be made aware of the infections so that care should be taken to avoid the spread of infection in water sources or in immunocompromised individuals.