Phylogenetic Analyses of Rotavirus A from Cattle in Uruguay Reveal the Circulation of Common and Uncommon Genotypes and Suggest Interspecies Transmission

Abstract

Uruguay is one of the main exporters of beef and dairy products, and cattle production is one of the main economic sectors in this country. Rotavirus A (RVA) is the main pathogen associated with neonatal calf diarrhea (NCD), a syndrome that leads to significant economic losses to the livestock industry. The aims of this study are to determine the frequency of RVA infections, and to analyze the genetic diversity of RVA strains in calves in Uruguay. A total of 833 samples from dairy and beef calves were analyzed through RT-qPCR and sequencing. RVA was detected in 57.0% of the samples. The frequency of detection was significantly higher in dairy (59.5%) than beef (28.4%) calves (p < 0.001), while it did not differ significantly among calves born in herds that were vaccinated (64.0%) or not vaccinated (66.7%) against NCD. The frequency of RVA detection and the viral load were significantly higher in samples from diarrheic (72.1%, 7.99 log10 genome copies/mL of feces) than non-diarrheic (59.9%, 7.35 log10 genome copies/mL of feces) calves (p < 0.005 and p = 0.007, respectively). The observed G-types (VP7) were G6 (77.6%), G10 (20.7%), and G24 (1.7%), while the P-types were P[5] (28.4%), P[11] (70.7%), and P[33] (0.9%). The G-type and P-type combinations were G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), and the uncommon genotype G24P[33] (1.8%). VP6 and NSP1-5 genotyping were performed to better characterize some strains. The phylogenetic analyses suggested interspecies transmission, including transmission between animals and humans.

Causes of neonatal calf diarrhea and mortality in pasture-based dairy herds in Uruguay: a farm-matched case-control study

“…This is remarkable given the high frequency of detection of these agents at the farm level. The detection frequencies of rotavirus in diarrheic (24.2%) or non-diarrheic (11.1%) calves in our study were much lower than those reported by RT-qPCR by Castells et al [46] in the same country using mostly the same sample set (72.1% and 59.9%, respectively). In our study, this frequency is probably underestimated considering that the detection limit and the sensitivity of the antigen-capture ELISA are lower than RT-qPCR, mainly in subclinical infections, and neutralizing antibodies derived either from colostrum or active immune responses may interfere with viral detection by antigen-capture ELISA [47].…”

Viral Enteritis in Cattle: To Well Known Viruses and Beyond

“…The current strategy to control the disease in cattle is based on the vaccination of cows during the last third of gestation to protect calves by transferring passive maternal antibodies through the ingestion of colostrum [44]. Although vaccines seem not to be effective in preventing RVA infection, they significantly reduce morbidity, the severity of diarrhea, and mortality related to RVA [44,45].…”

“…The interspecies transmission has been documented for rotavirus [45], coronavirus [169], astrovirus [88,92], kobuvirus [131,170], pestivirus [171], and enterovirus [172,173]. Notably, the zoonotic potential has been discussed for rotavirus [45], coronavirus [174], nebovirus [175], and enterovirus [172,173].…”

Rotaviruses and Rotavirus Vaccines

“…Understanding the diversity of strains in various animal populations is important for animal health and farming practices, as well as being informative for the contextualisation of zoonotic transmission events. Castells et al reported detection of rotavirus in calves reared for beef and dairy production in Uruguay [ 24 ]. Multiple genotypes associated with bovine disease were detected including G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), as well as the uncommon genotype G24P[33] (1.8%) [ 24 ].…”

“…Castells et al reported detection of rotavirus in calves reared for beef and dairy production in Uruguay [ 24 ]. Multiple genotypes associated with bovine disease were detected including G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), as well as the uncommon genotype G24P[33] (1.8%) [ 24 ].…”