Severe diarrhea outbreak in beef calves (Bos indicus) caused by G6P[11], an emergent genotype of bovine rotavirus group A / Surto de diarreia neonatal em bezerros de corte (Bos indicus) ocasionado por um genotipo emergente G6P[11] de rotavírus bovino grupo A

The episodes of diarrhea caused by neonatal bovine rotavirus group A (BoRVA) constitute one of the major health problems in the calf rearing worldwide. The main G (VP7) and P (VP4) genotypes of BoRVA strains involved in the etiology of diarrhea in calves are G6P[1], G10P[11], G6P[5], and G8P[1]. However, less frequently, other G and P genotypes have been described in BoRVA strains identified in diarrheic fecal samples of calves. This study describes the identification and molecular characterization of an emerging genotype (G6P[11]) in BoRVA strains involved in the etiology of a diarrhea outbreak in beef calves in a cattle herd of high production in extensive management system. The diarrhea outbreak, which showed high morbidity (60%) and lethality (7%) rates, occurred in calves (n= 384) Nelore (Bos indicus) up to 30-day-old from the State of Mato Grosso do Sul, Brazil. BoRVA was identified in 80% (16/20) of the fecal samples analyzed by polyacrylamide gel electrophoresis (PAGE) technique. In all PAGE-positive fecal samples were amplified products with 1,062-bp and 876-bp in the RT-PCR assays for VP7 (G type) and VP4 (VP8*) (P type) of BoRVA, respectively. The nucleotide sequence analysis of VP7 and VP4 genes of four wild-type BoRVA strains showed G6-III P[11]-III genotype/lineage. The G6P[11] genotype has been described in RVA strains of human and animal hosts, however, in calves this genotype was only identified in some cross-sectional studies and not as a single cause of diarrhea outbreaks in calves with high morbidity and lethality rates as described in this study...

Os episódios de diarreia neonatal ocasionados pelo rotavírus bovino grupo A (BoRVA) constituem-se em um dos principais problemas sanitários na criação de bezerros em todo o mundo. Os principais genotipos G (VP7) e P (VP4) de cepas de BoRVA envolvidos na etiologia da diarreia em bezerros são G6P[1], G10P[11], G6P[5] e G8P[1]. No entanto, com menor frequência, outros genotipos G e P têm sido descritos em cepas de BoRVA identificadas em amostras de fezes diarreicas de bezerros. Este estudo descreve a identificação e caracterização molecular de um genotipo emergente (G6P[11]) em cepas de BoRVA envolvidas na etiologia de um surto de diarreia em bezerros de um rebanho bovino de corte de alta produção em sistema de manejo extensivo. O surto, que apresentou altas taxas de morbidade (60%) e de letalidade (7%), ocorreu em bezerros (n=384) da raça Nelore (Bos indicus) com até 30 dias de idade, provenientes do estado do Mato Grosso do Sul, Brasil. O BoRVA foi identificado em 80% (16/20) das amostras fecais analisadas pela técnica de eletroforese em gel de poliacrilamida (PAGE). Em todas as amostras fecais PAGE-positivas foi possível a amplificação por RT-PCR de produtos com 1.062 pb e 876 pb referentes aos genes VP7 (G tipo) e VP4 (VP8*) (P tipo), respectivamente, de BoRVA. A análise da sequência de nucleotídeos dos genes VP7 e VP4 de quatro cepas de BoRVA demonstrou a presença do genotipo/linhagem G6-III P[11]-III. O genotipo G6P[11] tem sido descrito em cepas de RVA de hospedeiros humanos e animais. Contudo, em bezerros, este genotipo foi apenas identificado em alguns estudos transversais e não como a única causa de surtos de diarreia em bezerros com altas taxas de morbidade e...

Detection and characterization of group a rotaviruses (RVA) detected in diarrhoeic children in Madhya Pradesh, Central India.

Background and objectives: Rotavirus is the leading cause of viral gastroenteritis throughout the world and is associated with up to 600000 deaths worldwide every year, of which more than 150,000 occur in India. This study was undertaken to detect and analyze the human rotavirus A (RVA) isolates from Madhya Pradesh, central India, between 2007 and 2008.Methods: Forty diarrhoeic samples from children up to the age of 5 years, admitted or visited the hospital, were screened using RNA-viral electrophoresis (PAGE), reverse transcription (RT)-PCR and selected isolates were further analyzed by sequencing.Results and interpretation: Incidence of RV was 32.5% in children (13/40) and all the isolates showed a typical migration pattern of 4:2:3:2, suggestive of group A RVs. All the PAGE positive samples yielded positive amplification in RT-PCR, confirming them to be human RVA. The VP7 gene sequence analysis of the selected isolates (H-14 and H-16) identified as G1 type revealed that these isolates form a cluster with Indian G1 isolates (mani63-06 and mani 365-07) and strain from Bangladesh (DH378) with sequence identity of more than 97% at amino acid levels. Simplot and boot scan analysis showed no recombination with other G1 strains.Conclusions: The G1 was detected to be the predominant genotype in this area of the country, which is helpful in selecting the vaccine strain.