Faeces samples from 218, 1 to 30-day-old, diarrheic dairy calves in 65 dairy herds were screened for the presence of Cryptosporidium and concurrent infections with rotavirus, coronavirus, F5 Escherichia coli and Salmonella spp. Calves were grouped according to their age as follows: 1-7, 8-14, 15-21 and 22-30 days. Cryptosporidium infection was detected in 43.8%, 71.9%, 63.2% and 6.9% of the calves in the respective age groups. Significant differences in the detection rate of Cryptosporidium were found between the age group 22-30 days and all other age groups, and between the age group 1-7 days and the age groups 8-14 days and 15-21 days. Cryptosporidium was the only enteropathogen detected in 60 of the 114 (52.6%) diarrheic calves. Concurrent infections with other enteropathogen(s) were detected in 64.3%, 46.3%, 39.5% and 0% of the Cryptosporidium-infected calves in the age groups 1-7, 8-14, 15-21 and 22-30 days, respectively. A significant age-associated decrease in the detection rate of mixed infections (p < 0.05) was found. The detection rates of the other enteropathogens considered in calves with Cryptosporidium infection were 87% for rotavirus, 11.1% for coronavirus, 27.8% for F5+ E. coli and 1.8% for Salmonella.

Faecal samples from 218 diarrheic dairy calves in 65 dairy herds, selected by convenience, were screened for the presence of rotavirus, coronavirus, Cryptosporidium spp., F5+ Escherichia coli and Salmonella spp. Animals surveyed were from 1 to 30 days old. Cryptosporidium and rotavirus were the most commonly detected agents (52.3% and 42.7% of the samples positive, respectively). F5+ E. coli was detected in the faeces of 11.9% of the calves and bovine coronavirus was detected in the faeces of 7.3% of the calves. Salmonella spp. was only found in the faeces of two calves (0.9%). Mixed infections with two or more agents occurred in 28% of the calves. Concurrent infection of rotavirus and Cryptosporidium was found in 21.6% of the calves. Two tests were used for the detection of rotavirus (a commercial ELISA and PAGE), F5+ E. coli (ELISA and bacterial culture) and Cryptosporidium (ELISA and microscopy). The validity of the commercial ELISA for the detection of rotavirus, F5+ E. coli and Cryptosporidium in faeces from diarrheic calves was evaluated using PAGE, bacterial culture and microscopy as gold standard, respectively. The ELISA showed a very low sensitivity (28.6%) for the detection of F5+ E. coli compared to bacterial culture.

Faeces samples from 218, one to 30 days old, diarrheic dairy calves in 65 dairy herds were screened for the presence of rotavirus and concurrent infections with coronavirus, Cryptosporidium, F5+ Escherichia coli and Salmonella spp. Calves were grouped according to their age as follows: 1-7, 8-14, 15-21 and 22-30 days. Rotavirus infection was detected in 46.9%, 45.6%, 33.8% and 48.3% of the calves in the respective age-groups. No significant differences in the detection rate of rotavirus were found among calves on the different age-groups. Rotavirus was the only enteropathogen detected in 39 of the 93 (41.9%) diarrheic calves positive to this agent. Concurrent infections with other enteropathogen(s) were detected in 31.3%, 33.3%, 20.6% and 3.4% of the rotavirus infected calves in the age-groups 1-7, 8-14, 15-21 and 22-30 d, respectively. A significant age-associated decrease in the detection rate of mixed infections (p < 0.01) was found. The detection rates of the other enteropathogens considered in calves with rotavirus infection were 20.4% for coronavirus, 85.2% for Cryptosporidium, 16.7% for F5+ E. coli and 1.8% for Salmonella.

A freqüência de rotavírus do grupo A foi avaliada em 194 amostras, de fezes de bezerros, com idade entre 2 e 60 dias, provenientes de 33 propriedades da bacia leiteira de Pará de Minas, Minas Gerais. Utilizando um sistema de ELISA monoclonal direto, 33 (17%) destas amostras foram positivas para rotavírus do grupo A. Do total de animais positivos para rotavírus do grupo A, 60,6% apresentavam diarréia no momento da coleta. Das 33 propriedades amostradas, a presença de rotavírus foi detectada em 19 (57,6%). Dentre todas as amostras examinadas, somente 7 apresentaram simultaneamente rotavírus e Cryptosporidium spp.

A Neospora caninum 17 kDa protein fraction (p17) has been described as an immunodominant antigen (IDA) under reducing and non-reducing conditions. The aim of the present study was to investigate the diagnostic utility of p17 in cattle. In order to achieve this, p17 was purified by electroelution from whole N. caninum tachyzoite soluble extract and a p17-based Western blot