Mixed infections by bovine coronavirus, rotavirus and cryptosporidium parvum in an outbreak of neonatal diarrhea in beef cattle

ABSTRACT This article describes the role of bovine coronavirus, rotavirus and Cryptosporidium parvum in an outbreak of beef calf diarrhea in Presidente Epitácio, São Paulo State. Two out 9 fecal samples were positive to BCoV, 6 to C. parvum and 6 to rotavirus, with 4 rotavirus-C. parvumco-infections, 1 BCoV-C. parvumco-infection and 1 rotavirus-BCoV co-infection. These results show the need for a detailed survey of the etiology of diarrheas, aiming to evaluate the agents spread in a flock, allowing the design of prophylactic measures against gastroenteritis outbreaks.

RESUMO Estudou-se a participação de coronavírus bovino (BCoV) rotavírus e Cryptosporidium parvum em um surto de diarréia em bezerros de corte no Município de Presidente Epitácio, Estado de São Paulo. Das 9 amostras colhidas, 2 foram positivas para BCoV, 6 para C. parvum e 6 para rotavírus, sendo 4 co-infecções por rotavírus e C. parvum, 1 coinfecção por BCoV e C. parvume 1 co-infecção por rotavírus e coronavírus. Estes resultados reiteram a necessidade de que se pesquise de um modo abrangente a etiologia de diarréias, com o intuito de se avaliarem os agentes circulantes no rebanho, o que possibilita uma abordagem profilática mais exata para impedir o aparecimento de surtos epidêmicos de gastroenterites.

An enteric coronavirus in a 3-day-old diarrheic foal

ABSTRACT Coronaviruses are of special interest in diarrhea of horses, once they cause disease in foals and in the adult. This study aimed to evaluate the existence of coronavirus, rotavirus, protozoa and bacteria in stool of a 3-day old foal suffering from acute diarrhea. A nested PCRassay for the RNA-dependent RNA-polymerase gene was applied to coronavirus detection and PAGE, sucrose flotation test and classical bacteriology for rotavirus, protozoa and bacteria detection, respectively. An enteric group II coronavirus was found with no concurrent infections. The role of coronavirus in this clinical case is discussed, as well as possible transmission routes.

RESUMO Coronavírus têm um interesse especial em cavalos, uma vez que causam doenças em potros e adultos. Este estudo objetivou avaliar a existência de coronavírus, rotavírus, protozoários e bactérias em fezes de um potro com 3 dias de idade sofrendo de diarréia aguda. Uma reação de nested-RT-PCR para o gene da RNA-polimerase RNA-dependente foi aplicada para a detecção de coronavírus e as provas de PAGE, teste de flutuação em sacarose e bacteriologia clássica foram aplicadas para a pesquisa de rotavírus, protozoários e bactérias, respectivamente. Um coronavírus entérico do grupo II foi encontrado, sem outras infecções ou infestações simultâneas. O papel dos coronavírus neste caso clínico é discutido no presente artigo, bem como as possíveis vias de transmissão.

Rotavirus detection and isolation from chickens with or without symptoms

Rotaviruses have been identified as one of the main etiological agents of diarrhea and enteritis in mammals, including humans, and in avian species. Few studies have been published about enteric viruses in Brazilian poultry, including those related to rotavirus infection. Such studies demonstrate significant occurrence and the importance of enteric viruses in poultry presenting intestinal problems. Enteric viruses are the primary cause of injuries to the gut, allowing other agents, especially bacteria, to attach, to penetrate, and to replicate in the enteric tissue, leading to further damage. The aim of the present study was to detect rotavirus in the intestinal contents of layers and broilers by polyacrylamide gel electrophoresis (PAGE) and virus isolation in MA-104 cell culture. A total of 45.3% of all samples were positive to rotavirus; rotavirus frequencies were 48.7% in samples from flocks with diarrhea, 46.4% in flocks with delayed growth, and 30% in asymptomatic flocks. It was possible to isolate rotavirus in MA-104 cells from the nine rotavirus-positive randomly chosen samples. These results indicate that rotavirus may have an important role in pathogenesis of enteric disease.

Rotavirus detection and isolation from chickens with or without symptoms

Rotaviruses have been identified as one of the main etiological agents of diarrhea and enteritis in mammals, including humans, and in avian species. Few studies have been published about enteric viruses in Brazilian poultry, including those related to rotavirus infection. Such studies demonstrate significant occurrence and the importance of enteric viruses in poultry presenting intestinal problems. Enteric viruses are the primary cause of injuries to the gut, allowing other agents, especially bacteria, to attach, to penetrate, and to replicate in the enteric tissue, leading to further damage. The aim of the present study was to detect rotavirus in the intestinal contents of layers and broilers by polyacrylamide gel electrophoresis (PAGE) and virus isolation in MA-104 cell culture. A total of 45.3% of all samples were positive to rotavirus; rotavirus frequencies were 48.7% in samples from flocks with diarrhea, 46.4% in flocks with delayed growth, and 30% in asymptomatic flocks. It was possible to isolate rotavirus in MA-104 cells from the nine rotavirus-positive randomly chosen samples. These results indicate that rotavirus may have an important role in pathogenesis of enteric disease.

Caracterização eletroforética e análise de subgrupo de rotavírus em rebanhos bovinos leiteiros do Estado de São Paulo

A study was accomplished to determine the occurrence of rotavirus in feces of calves, in the State of São Paulo, Brazil. A total of 375 samples of feces from calves 1 to 45 day-old were collected. The animals belonged to farms situated in six counties of the northeast region of the State. One hundred and ninety tree out of these samples belonged to animals with a clinical picture of diarrhea and 182 were obtained from clinically healthy animals. The techniques used for the detection of rotavirus were the enzyme immunoassay (EIA) and the polyacrilamide gel electrophoresis (PAGE). By the use of EIA, 11.2% (42/375) of the samples were positive for rotavirus. Among the samples of diarrheic calves, 15% (29/193) were found to be positive for rotavirus, whereas 7.1 (13/182) positive samples were obtained from clinically healthy animals. The PAGE test presented a lower sensitivity than EIA, since from the 42 positive samples in EIA, only 36 presented an electrophoretical profile characteristic of rotavirus. The genome analysis indicated the presence of six distinct electrophoretical types characteristic of group A rotavirus. A unique electropherotype was detected in tree farms, which remained constant during the sampling period. In two farms a second electropherotype was detected. The serological characterization of the positive samples in subgroups was accomplished through EIA with "double sandwich", utilizing monoclonal antibodies ( I and II). Twenty two group A rotavirus strains I (52.4%, 22/42) reacted with MAb of subgroup I, none to subgroup II, and the remaining 47.6% (20/42) did not react with the two subgroups.

Foi realizado um estudo para determinar a ocorrência de infecção por rotavírus em rebanhos bovinos leiteiros. Foram analisadas 375 amostras de fezes de bezerros, na faixa etária 1 a 45 dias, provenientes de animais pertencentes a nove propriedades rurais, situadas em seis municípios da região nordeste do Estado de São Paulo. Destas, 193 pertenciam a animais com diarréia e 182 foram obtidas de animais clinicamente sadios. As técnicas utilizadas para a detecção de rotavírus foram o ensaio imunoenzimático (EIE) e a eletroforese em gel de poliacrilamida (EGPA). Por meio do EIE foram detectadas 11,2% (42/375) de amostras positivas, 15% delas (29/193) obtidas de animais com diarréia e 7,1% (13/182) colhidas de animais sem diarréia. A análise do perfil do genoma indicou a presença de seis eletroferótipos distintos, característicos de rotavírus do grupo A. Um único eletroferótipo foi detectado em três rebanhos, o qual permaneceu constante durante o período de amostragem. Em dois rebanhos diferentes eletroferótipos foram detectados, embora com maior prevalência de um dado perfil. A caracterização das amostras positivas em subgrupos foi realizada por meio do EIE com "duplo sanduíche", utilizando-se anticorpos monoclonais (MAb) específicos para antígenos de subgrupo (I e II). Foram caracterizadas como subgrupo I 52,4% (22/42) das amostras testadas, nenhuma reagiu com MAb de subgrupo II, enquanto as demais, 47,6% (20/42), não reagiram com nenhum dos dois subgrupos.