Characterization of coccidiosis and evaluation of suggestive cases of subclinical necrotic enteritis in broilers / Caracterização de coccidiose e avaliação de casos sugestivos de enterite necrótica subclínica em frangos de corte

This study performed the characterization of coccidiosis in broilers and evaluated the occurrence of suggestive cases of necrotic enteritis (NE), seeking if there is an association between the diseases in Brazilian flocks. Two hundred and fifty-six birds from 32 flocks were evaluated. Macroscopic and histopathological lesions were graduated for coccidiosis and NE. Intestinal content was investigated by polymerase chain reaction (PCR) for seven species of Eimeria and by selective anaerobic culture for Clostridium perfringens and identification of the NetB gene. Flocks positive for coccidiosis represented 93.8%. Macroscopic lesions of coccidiosis were Grade 1 for E. acervulina (27%); E. tenella (9.7%) and E. maxima (8.9%). Histopathological evaluation showed Grade 1 in duodenum (38.2%); jejunum (21.4%); cecum (9.3%) and ileum (5%). PCR demonstrated positivity for E. tenella (21.9%), E. maxima (18.8%), and E. acervulina (3.1%). Suggestive macroscopic lesions of necrotic enteritis ranged from Grade 1 (16%), 2 (23%) and 3 (10,9%). Histopathology indicated the absence of necrosis, showing only hemorrhage in the mucosa and submucosa, with the presence of Eimeria spp. Clostridium perfringens type A netB+ was not isolated, demonstrating that macroscopic lesions found mostly in the jejunum did not characterize NE, based on histopathology and negativity of the NetB gene. The study suggests that, due to the high occurrence of coccidiosis, many macroscopic findings suggestive of NE are, in fact, attributed to atypical lesions caused by the reproduction of Eimeria spp.

Este estudo realizou a caracterização de coccidiose em frangos de corte e avaliou a ocorrência de casos sugestivos de enterite necrótica (EN), buscando se há alguma associação entre estas duas enfermidades em lotes de frango de corte no Brasil. Foram avaliadas 256 aves de 32 lotes. Lesões macroscópicas e histopatológicas foram graduadas para coccidiose e EN. O conteúdo intestinal foi investigado por reação em cadeia da polimerase (PCR) para sete espécies de Eimeria e por cultura anaeróbia seletiva para Clostridium perfringens e identificação do gene NetB. Os lotes positivos para coccidiose representaram 93,8%. Lesões macroscópicas de coccidiose foram de Grau 1 para E. acervulina (27%); E. tenella (9,7%) e E. maxima (8,9%). A avaliação histopatológica mostrou Grau 1 no duodeno (38,2%); jejuno (21,4%); ceco (9,3%) e íleo (5%). A PCR demonstrou positividade para E. tenella (21,9%), E. maxima (18,8%) e E. acervulina (3,1%). Lesões macroscópicas sugestivas de enterite necrótica variaram de grau 1 (16%), 2 (23%) e 3 (10,9%). A histopatologia indicou ausência de necrose, apresentando apenas hemorragia em mucosa e submucosa, com presença de Eimeria spp. Clostridium perfringens tipo A netB + não foi isolado, demonstrando que lesões macroscópicas encontradas principalmente no jejuno não caracterizaram NE, com base na histopatologia e negatividade do gene NetB. O estudo sugere que, em virtude da alta ocorrência de coccidiose nos lotes, muitos achados macroscópicos sugestivos de EN são, na verdade, atribuídos a lesões atípicas provocadas pela reprodução de Eimeria spp.

Necrohemorrhagic enteritis outbreak in a cattle feedlot in Nova Crixás, Goiás, Brazil / Surto de enterite necro-hemorrágica em um confinamento de bovinos no município de Nova Crixás, Goiás, Brasil

This study described an outbreak of necrohemorrhagic enteritis in a beef cattle feedlot in Nova Crixás, State of Goiás, Brazil, with emphasis on epidemiological, lesional, and laboratory aspects. Visits to the property were carried out and a necroscopic examination was performed on the bovine cadavers (N=57), which presented similar macroscopic alterations. Epidemiological data were collected, mainly referring to the feeding management of animals, and tissue samples were submitted to histopathological examination. Samples of feces and intestinal contents were also collected for bacterial isolation and PCR genotyping to detect the etiological agent, being confirmed Clostridium perfringens type A strains in 100% of the samples. Furthermore, 33.3% of strains isolated from intestinal contents and 40% of those isolated from feces were positive for beta-2 encoding gene. Considering the history, macroscopic and microscopic findings, as well as bacterial isolation and PCR, the diagnosis of bovine necrohemorrhagic enteritis was determined.(AU)

Descreve-se um surto de enterite necro-hemorrágica em um confinamento de bovinos de corte no município de Nova Crixás, Estado de Goiás, Brasil, com ênfase nos aspectos epidemiológicos, lesionais e laboratoriais. Foram realizadas visitas à propriedade e todos os cadáveres bovinos (N=57) foram submetidos ao exame necroscópico, os quais apresentaram alterações macroscópicas semelhantes. Foram compilados dados epidemiológicos, sobretudo referentes ao manejo alimentar dos animais e amostras de tecido foram submetidas a exame histopatológico. Foram colhidas, também, amostras de fezes e conteúdo intestinal para isolamento bacteriano e genotipagem por PCR para detecção do agente etiológico, sendo confirmadas estirpes de Clostridium perfringens tipo A em 100% das amostras. Ainda, 33,3% das cepas de Clostridium perfringens isoladas no conteúdo intestinal e 40% daquelas isoladas nas fezes foram positivas para o gene codificador da toxina beta-2. Considerando o histórico, os achados macroscópicos e microscópicos, o isolamento bacteriano e o PCR, foi estabelecido o diagnóstico de enterite necro-hemorrágica por C. perfringens tipo A.(AU)

Necrohemorrhagic enteritis outbreak in a cattle feedlot in Nova Crixás, Goiás, Brazil / Surto de enterite necro-hemorrágica em um confinamento de bovinos no município de Nova Crixás, Goiás, Brasil

This study described an outbreak of necrohemorrhagic enteritis in a beef cattle feedlot in Nova Crixás, State of Goiás, Brazil, with emphasis on epidemiological, lesional, and laboratory aspects. Visits to the property were carried out and a necroscopic examination was performed on the bovine cadavers (N=57), which presented similar macroscopic alterations. Epidemiological data were collected, mainly referring to the feeding management of animals, and tissue samples were submitted to histopathological examination. Samples of feces and intestinal contents were also collected for bacterial isolation and PCR genotyping to detect the etiological agent, being confirmed Clostridium perfringens type A strains in 100% of the samples. Furthermore, 33.3% of strains isolated from intestinal contents and 40% of those isolated from feces were positive for beta-2 encoding gene. Considering the history, macroscopic and microscopic findings, as well as bacterial isolation and PCR, the diagnosis of bovine necrohemorrhagic enteritis was determined.(AU)

Descreve-se um surto de enterite necro-hemorrágica em um confinamento de bovinos de corte no município de Nova Crixás, Estado de Goiás, Brasil, com ênfase nos aspectos epidemiológicos, lesionais e laboratoriais. Foram realizadas visitas à propriedade e todos os cadáveres bovinos (N=57) foram submetidos ao exame necroscópico, os quais apresentaram alterações macroscópicas semelhantes. Foram compilados dados epidemiológicos, sobretudo referentes ao manejo alimentar dos animais e amostras de tecido foram submetidas a exame histopatológico. Foram colhidas, também, amostras de fezes e conteúdo intestinal para isolamento bacteriano e genotipagem por PCR para detecção do agente etiológico, sendo confirmadas estirpes de Clostridium perfringens tipo A em 100% das amostras. Ainda, 33,3% das cepas de Clostridium perfringens isoladas no conteúdo intestinal e 40% daquelas isoladas nas fezes foram positivas para o gene codificador da toxina beta-2. Considerando o histórico, os achados macroscópicos e microscópicos, o isolamento bacteriano e o PCR, foi estabelecido o diagnóstico de enterite necro-hemorrágica por C. perfringens tipo A.(AU)

Clostridium perfringens e a enterite necrótica em frangos: principais fatores de virulência, genéticos e moleculares

Clostridium perfringens é o causador da enterite necrótica que afeta a produção de frangos de corte no mundo todo. Essa bactéria produz diversas toxinas e causa lesões no intestino, tendo como consequências a elevada mortalidade e perdas econômicas devido à baixa produtividade. Nesta revisão são apresentados os principais fatores de virulência, a susceptibilidade aos antimicrobianos e a diversidade genética de C. perfringens isolados de frangos com enterite necrótica.(AU)

Clostridium perfringens cause necrotic enteritis affecting the poultry production worldwide. This bacterium produces various toxins and causes lesions in the intestine producing high mortality and economic loss due to the low productivity.In this review, the major virulence factors, antimicrobial susceptibility and genetic diversity of C. perfringens from chickens with necrotic enteritis are showed.(AU)

Clostridium perfringens e a enterite necrótica em frangos: principais fatores de virulência, genéticos e moleculares

Clostridium perfringens é o causador da enterite necrótica que afeta a produção de frangos de corte no mundo todo. Essa bactéria produz diversas toxinas e causa lesões no intestino, tendo como consequências a elevada mortalidade e perdas econômicas devido à baixa produtividade. Nesta revisão são apresentados os principais fatores de virulência, a susceptibilidade aos antimicrobianos e a diversidade genética de C. perfringens isolados de frangos com enterite necrótica.

Clostridium perfringens cause necrotic enteritis affecting the poultry production worldwide. This bacterium produces various toxins and causes lesions in the intestine producing high mortality and economic loss due to the low productivity.In this review, the major virulence factors, antimicrobial susceptibility and genetic diversity of C. perfringens from chickens with necrotic enteritis are showed.

Detection of toxins A/B and isolation of Clostridium difficile and Clostridium perfringens from dogs in Minas Gerais, Brazil

The objective of this study was to detect C. difficileA/B toxins and to isolate strains of C. perfringensand C. difficile from diarrheic and non-diarrheic dogs in Brazil. Stool samples were collected from 57 dogs, 35 of which were apparently healthy, and 22 of which were diarrheic. C. difficileA/B toxins were detected by ELISA, and C. perfringensand C. difficilewere identified by multiplex PCR. C. difficileA/B toxins were detected in 21 samples (36.8%). Of these, 16 (76.2%) were from diarrheic dogs, and five (23.8%) were from non-diarrheic dogs. Twelve C. difficile strains (21.1%) were isolated, of which ten were A+B+and two were A-B-. All non-toxigenic strains were isolated from non-diarrheic animals. The binary toxin gene cdtBwas found in one strain, which was A+B+and was derived from a non-diarrheic dog. C. perfringensstrains were isolated from 40 samples (70.2%). Of these, 18 (45%) were from the diarrheic group, and 22 (55%) belonged to the non-diarrheic group. All isolates were classified as C. perfringenstype A and there was an association between the detection of the cpegene and the presence of diarrhea. Interestingly, ten strains (25%) were positive for the presence of the cpb2gene. The high rate of detection of the A/B toxins in non-diarrheic dogs suggests the occurrence of subclinical disease in dogs or carriage of its toxins without disease. More studies are needed to elucidate the epidemiology of C. difficileand C. perfringensin dogs and to better our understanding of C. difficileas a zoonotic agent. This is the first study to report the binary toxin gene in C. difficilestrains isolated from dogs in Brazil.(AU)

Molecular detection and characterization of cpb2 gene in Clostridium perfringens isolates from healthy and diseased chickens

Clostridium perfringens is an important pathogen in both human and veterinary medicine. Necrotic enteritis (NE) is the most clinically dramatic bacterial enteric disease of poultry induced by C. perfringens. The pathogenicity of this bacterium is associated with the production of extracellular toxins produced by some of its strains, such as beta2 toxin. The exact role of beta2 toxin in NE pathogenesis is still controversial. In the present study, C. perfringens isolates from healthy and diseased poultry flocks from different parts of Iran were analyzed by PCR assay to determine the presence of all variants of the beta2 toxin gene (cpb2). The products of two positive cpb2 PCR reactions were sequenced, compared to each other and to the cpb2 sequences published in GenBank (by multiple alignment and phylogenetic analysis). The current work represents the first study of cpb2 in poultry C. perfringens isolates in Asia, and reports the highest percentage of cpb2-positive isolates in both apparently healthy chickens (97.7 percent) and those afflicted with NE (94.4 percent). The sequenced isolates were classified as atypical. This study did not show a direct correlation between NE occurrence and cpb2 presence.(AU)