Prevalence of group A and group B rotaviruses in the feces of neonatal dairy calves from California

Abstract

136 fecal samples, collected from 47 dairy calves on a calf ranch and in a dairy herd in California, were tested for the presence of group A and group B rotaviruses by reverse transcription-polymerase chain reaction (RT-PCR). Samples were collected from each calf at days 1, 7 and 14. Within the 14 day period, 44 calves (94%) were positive for group A rotavirus and an unexpectedly high number of calves (38 calves, 81%) were positive for group B rotavirus. When these samples were examined by polyacrylamide gel electrophoresis (PAGE), rotavirus was found in 21 calves and all of them had group A electropherotype. Among 25 PAGE positive samples from 21 calves, 17 (68%) were of short electropherotype, 4 (28%) were of long electropherotype and 4 (28%) contained both short and long electropherotype rotaviruses. Group B and short and long electropherotype group A rotaviruses were found in both normal and diarrheic calves.

Detection of Rotavirus Infection in Bovine Calves by RNA-PAGE and RT-PCR

“…These samples might possibly represent group A bovine rotaviruses with an unusual genome segment 6 sequence that was possibly not amplified by partial length VP6 specific primers. Similar findings were reported by Chinsangaram et al[1] in a study where out of 47 PAGE positive samples, three samples were found negative for group A rotavirus by RT-PCR which were thought to contain unusual genome segment 6 sequence. In a study by Rodriguez-Limas et al[13], group A rotavirus has been found in 10% (12/128) of screened samples from dairy and beef calves with an immunocard that detected group A rotavirus VP6 gene.…”

“…In a study by Rodriguez-Limas et al[13], group A rotavirus has been found in 10% (12/128) of screened samples from dairy and beef calves with an immunocard that detected group A rotavirus VP6 gene. In another study by Theil et al[19] group A rotavirus has been found in 22% of diarrhoeic calves from dairy and beef herds by cell culture immunofluorescence assay and Chinsangaram et al[1] detected group A rotavirus from 94% (44/47) calves, directly by RT-PCR in faecal samples. The present study confirms the circulation of group A rotavirus in the region and further studies are required to characterize the genotypes prevalent and their zoonotic implications.…”

Pathophysiology of Diarrhea in Calves

“…114,115 Antibodies to rotavirus can be found in more than 90% of unvaccinated cattle, 116 and the virus was isolated from 94% of dairy calves at a large dairy and calf ranch during the first 2 weeks of life. 117 It has also been isolated from approximately 20% of calf diarrhea samples, 118,119 and from at least one calf on 63% of farms. 120 Calves become infected after ingesting the virus from fecal contamination of the environment, because the virus remains quite stable if the temperature does not get near freezing.…”

Biosecurity and Risk Management for Dairy Replacements

“…In weaned heifers, another important endemic disease is infectious bovine keratoconjunctivitis (IBK, or pinkeye), caused by Moraxella bovis [38]. With the exception of BVDV, some Salmonella species, some mycoplasmal species, and some specific strains of E coli, the pathogens responsible for most calfhood disease are ubiquitous and are present in a proportion of apparently healthy cattle on most dairy operations [39][40][41][42][43][44][45].…”