An extensive field study reveals the circulation of new genetic variants of subtype 1a of bovine viral diarrhea virus in Uruguay

Abstract

Bovine viral diarrhea virus (BVDV) is a major pathogen worldwide, causing significant economic losses to the livestock sector. In Uruguay, BVDV seroprevalence at the farm level is >80%. In this work, 2546 serum, blood or tissue samples collected from animals suspected of being affected by BVD between 2015 and 2017 were analyzed by reverse transcription PCR and sequencing. Analysis of the BVDV genomic regions 5'UTR/N pro , N pro and E2 revealed that BVDV-1a, 1i and 2b circulate in the country, with BVDV-1a being the most prevalent subtype. Population dynamics studies revealed that BVDV-1a has been circulating in our herds since ~1990. This subtype began to spread and evolve, accumulating point mutations at a rate of 3.48 × 10 −3 substitutions/site/year, acquiring specific genetic characteristics that gave rise to two local genetic lineages of BVDV-1a. These lineages are divergent from those circulating worldwide, as well as the vaccine strain currently used in Uruguay. The most notable differences between field and vaccine strains were found in the E2 glycoprotein, suggesting that the amino acid substitutions could result in failure of cross-protection/neutralization after vaccination. This is the first study that compares Uruguayan BVDV field and vaccine strains with other BVDV strains from throughout the world. The results obtained in this study will be very useful for developing a suitable immunization program for BVDV in Uruguay by identifying local field strains as candidates for vaccine development.

Seroprevalence of five diarrhea-related pathogens in bovine herds of scattered households in Inner Mongolia, China between 2019 and 2022

“…In Tibet and Qinghai of western China, seropositivity rates were above 53% in yaks, and the BVDV positivity rate was 35–41% in Gansu Province, 77.8% in Eastern China, and 100% in Shanxi Province ( Gao et al, 2013 ; Hou et al, 2019 ; Qin et al, 2019 ; Ma et al, 2016 ; Deng et al, 2020 ). Ricci et al (2019) found that BVDV-1 was detected in unvaccinated cattle in Italy (28%), and the positive rates was higher than 67% in Uruguay, Turkey and other countries ( Maya et al, 2020 ; Timurkan & Aydın, 2019 ; Aragaw et al, 2018 ; Nugroho et al, 2020 ). Comparing the above percentages, the authors suggest that the positive rate may be due to the fact that none of the cattle collected were vaccinated against BVDV, the most BVDV positive sera were detected in adult cattle (49.50%), probably due to natural infection or immunity produced by the organism itself after resistance.…”

Coding-complete genome sequences of two bovine viral diarrhea virus 1a isolates from Uruguay

“…The BVDV-1a subtype is predominant in Uruguay and is genetically distant from the NADL vaccine strain, potentially causing vaccination failure ( 7 ). We report the coding-complete sequences of two BVDV-1a Uruguayan isolates obtained by Illumina sequencing Technology.…”

Viral Enteritis in Cattle: To Well Known Viruses and Beyond

“…The pestiviruses possess a single-stranded positive-polarity RNA genome of approximately 12,300 nucleotides in length (Table 1). A single ORF encodes a single polyprotein that is cleaved into 11-12 structural and non-structural proteins, which is flanked at both ends by UTRs [122]. Pestiviruses possess an envelope (Table 1).…”

“…In the case of mutations, it is the main process used by all the viruses, being the mutation rate very high, mainly in viruses with an RNA genome. The nucleotide substitution rates estimated for some of the viruses included in this review are: 1.39 × 10 −3 substitution per site per year (s/s/y) for BCoV [53], 1.58 × 10 −2 s/s/y for BKV [131], 4.27 × 10 −4 s/s/y for bovine astrovirus (associated with encephalitis) [99], 2.78 × 10 −3 s/s/y-3.81 × 10 −3 for BoNoV [176,177], 1.40 × 10 −2 s/s/y for BEV [178], 1.14 × 10 −2 s/s/y for SBV [179], 3 × 10 −3 s/s/y for BToV [180], and 5.90 × 10 −4 -9.3 × 10 −3 for bovine pestivirus [122,181,182].…”