Yoshitani Geovana Depieri, Fritzen Juliana Torres Tomazi, Yasumitsu Carolina Yuka, Machado Beatriz Martins, Alfieri Alice Fernandes, Alfieri Amauri Alcindo
Laboratory of Animal Virology, Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Multi-User Animal Health Laboratory, Molecular Biology Unit, Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Braz J Microbiol. 2025 Jul 15. doi: 10.1007/s42770-025-01733-7.
Diarrhea is the primary cause of morbidity and mortality in piglets during the neonatal period. Porcine neonatal diarrhea is a complex disease often caused by porcine rotavirus (PoRV) worldwide. This report describes the diversity of species and genotypes of PoRV field strains currently circulating in the nursery pens of an unvaccinated pig herd in southern Brazil. In a cross-sectional survey, 12 diarrheic fecal samples were obtained from 1 to 3 weeks of suckling piglets during an outbreak of diarrhea. RT-PCR assays were utilized to investigate the RVA, RVB, RVC, and RVH species. The amplified products were sequenced using the Sanger method. All 12 fecal samples were PoRV-positives. Among them, 11 (91.7%) samples were positive for RVA and 8 (66.7%) for RVC. RVA and RVC were co-detected in 7 (58.3%) samples. RNA from only one PoRV species was detected in five (RVA; n = 4 and RVC; n = 1) samples. Further analysis of VP7 (genotype G), VP4 (genotype P), and VP6 (genotype I) genes showed a diversity of four different genotype combinations for RVA (G3-P [6]-I5, G3-P [13]-I5, G4-P [6]-I5, and G5-P [23]-I5) and two (G1-P [4]-I6 and G6-P [4]-I1) for RVC field strains. This genotype diversity is rare in cross-sectional studies involving just one fecal collection on only one pig farm. Despite the small sample size, these reports highlight the intricate nature of PoRV gene reassortment events in pig herds, which can change the epidemiology of PoRV infections. Monitoring the evolution of PoRV field strains and potential heterologous infections is crucial. This will enhance our understanding of the evolution of PoRV wild-type strains and the epidemiology of PoRV infections.
腹泻是仔猪新生期发病和死亡的主要原因。在全球范围内，猪新生腹泻是一种常由猪轮状病毒（PoRV）引起的复杂疾病。本报告描述了巴西南部一个未接种疫苗的猪群保育舍中目前流行的PoRV野毒株的种类和基因型多样性。在一项横断面调查中，腹泻暴发期间从1至3周龄的哺乳仔猪中采集了12份腹泻粪便样本。采用逆转录聚合酶链反应（RT-PCR）检测方法来研究RVA、RVB、RVC和RVH种类。扩增产物采用桑格法进行测序。所有12份粪便样本均为PoRV阳性。其中，11份（91.7%）样本RVA呈阳性，8份（66.7%）样本RVC呈阳性。7份（58.3%）样本中同时检测到RVA和RVC。5份样本（RVA；n = 4，RVC；n = 1）中仅检测到一种PoRV种类的RNA。对VP7（G基因型）、VP4（P基因型）和VP6（I基因型）基因的进一步分析显示，RVA有四种不同基因型组合（G3-P[6]-I5、G3-P[13]-I5、G4-P[6]-I5和G5-P[23]-I5），RVC野毒株有两种（G1-P[4]-I6和G6-P[4]-I1）。这种基因型多样性在仅涉及一个猪场一次粪便采集的横断面研究中较为罕见。尽管样本量较小，但这些报告突出了猪群中PoRV基因重配事件的复杂性，这可能会改变PoRV感染的流行病学。监测PoRV野毒株的演变和潜在的异源感染至关重要。这将增进我们对PoRV野生型毒株演变及PoRV感染流行病学的理解。
