Detection of a novel species A, DS-1-like, G4P[6] rotavirus strain from a Brazilian child with gastroenteritis.

Rotaviruses belonging to species A (RVA) remain among the most common causes of severe gastroenteritis in children aged <5 years, leading to substantial morbidity and mortality worldwide. Genome reassortment events between two human strains or human and animal strains represent one of the mechanisms which appear to generate the broad genetic variability of circulating. According to a nucleotide, sequence-based classification system, RVA strains are currently classified into three genotype constellations including Wa-like (genogroup I), DS-1-like (genogroup II), and AU-like (genogroup III). The present study reports the detection of an unusual RVA G4P[6] strain (coded as strain HSE005), which might have originated from a natural reassortment event between human and animal RVA strains. Molecular characterization of this isolate showed that it belonged to genogroup II, genotype G4P[6]. In addition, two genes (VP3 and NSP4) of this strain denoted evidence of reassortment events involving strains of distinct zoonotic evolutionary origins. Therefore, we propose that a new G4P[6] strain was identified, highlighting a possible first zoonotic transmission including a reassortment event that involved the VP3 gene.

Molecular analysis of G3P[6] rotavirus in the Amazon region of Brazil: evidence of reassortment with equine-like strains.

Aim: To perform a molecular analysis of rotavirus A (RVA) G3P[6] strains detected in 2012 and 2017 in the Amazon region of Brazil. Materials & methods: Eighteen RVA G3P[6] strains were collected from children aged under 10 years hospitalized with acute gastroenteritis, and partial sequencing of each segment genome was performed using Sanger sequencing. Results: Phylogenetic analysis showed that all G3P[6] strains had a DS-1-like genotype constellation. Two strains had the highest nucleotide identities with equine-like G3P[6]/G3P[8] genotypes. Several amino acid alterations in VP4 and VP7 neutralizing epitopes of equine-like RVA G3P[6] strains were observed in comparison with vaccine strains. Conclusion: These findings suggest that equine-like RVA G3P[6] strains have been circulating in the Amazon region of Brazil as a result of direct importation, and support natural RVA evolutionary mechanisms.

Highly symmetriaal crystallization in six rectiinear and well-defined axes fouund in bovine cervical mucus obtained at oestrus: a finding / Cristaización alltamene simétrica con seis ejes rectilíneos y bien deefinidos hallada en moco cervical bovino obtenido en estro

Bovine cervical mucus (BCM) is important for selection and transport of spermatozoa. When air-dried, BCM obtained at oestrus exhibits arborescent crystallizations, among other arrangements. Considering the relevant endocrine and reproductive information indirectly obtained from BCM crystallization, a morphological investigation was carried out to study its crystalline patterns. BCM samples were collected from healthy Holstein Friesian heifers at oestrus, their crystalline patterns photographed and its morphology analyzed. The majority of the crystallizations obtained showed the typical tree-like patterns reported for BCM. However, a highly symmetrical arrangement was found, characterized by a star-like morphology with six straight, highly defined axes that protrude from the same central point, forming 60º angles. In terms of current knowledge, this short report is the first to show this crystallization geometry in BCM, which, additionally, is remarkably similar to P6B mucus reported for periovulatory human cervical mucus. Even though the role of mucus presenting this type of crystallization is as yet unknown for bovines, its possible functions are also briefly discussed here.

El moco cervical bovino es importante para la selección y el transporte espermático. El moco, obtenido durante el estro y secado al aire, exhibe cristalizaciones con formas principalmente arborescentes. Considerando la importante información endocrina y reproductiva que es posible obtener a partir de la cristalización del moco cervical, se efectuó una investigación morfológica con el propósito de estudiar sus patrones cristalinos. Las muestras de moco se obtuvieron de novillas Holstein Friesian en estro; posteriormente, los patrones de cristalización del moco fueron fotografiados para finalmente analizar su morfología. Las cristalizaciones obtenidas correspondieron a típicos patrones arboriformes previamente reportados. Sin embargo, lo que llamó la atención fue el hallazgo de un arreglo altamente simétrico en una novilla, caracterizado por una morfología similar a estrella con seis ejes rectos, bien definidos, que surgen desde el mismo punto central y forman ángulos de 60º. Según nuestro conocimiento, esta comunicación breve reporta por primera vez la presencia de dicha geometría de cristalización en vaquillas, la cual es muy semejante al patrón cristalino subtipo P6 reportado para el moco cervical perioBvulatorio humano. Si bien el rol ejercido por este tipo de cristalización de moco aún se desconoce en bovinos, se discuten aquí sus posibles funciones.

Diversity of rotavirus strains circulating in Northern Brazil after introduction of a rotavirus vaccine: high prevalence of G3P[6] genotype.

Rotavirus A (RVA) is the most common cause of severe acute gastroenteritis in infants and young children worldwide, causing 453,000 deaths annually. In Brazil, the most frequent genotype identified was G1 during almost three decades in the pre-vaccination period; however, after anti-rotavirus vaccine introduction, there was a predominance of G2 genotype. The aim of this study was to determine the G and P genotypes of rotaviruses isolated from children under 5 years of age with acute gastroenteritis in the Northern region of Brazil, and discuss the emergence of G3P[6] genotype. A total of 783 stool specimens were obtained between January 2011 and March 2012. RVA antigen was detected in 33% (272/783) of samples using a commercial enzyme-linked immunosorbent assay and type-specificity was determined by reverse-transcription polymerase chain reaction. The most common binary combination was G2P[4], representing 41% of cases, followed by G3P[6] (15%), G1P[8] (8%), G3P[8] (4%), G9P[8] (3%), and G12P[6] (2%). G3P[6] strains were analyzed further and phylogenetic analysis of VP7 gene showed that G3 strains clustered into lineage I and showed a high degree of amino acid identity with vaccine strain RV3 (95.1-95.6%). For VP4 sequences, G3P[6] clustered into lineage Ia. It was demonstrated by the first time the emergence of unusual genotype G3P[6] in the Amazon region of Brazil. This genotype shares neither VP7 nor VP4 specificity with the used vaccine and may represent a challenge to vaccination strategies. A continuous monitoring of circulating strains is therefore needed during the post-vaccine era in Brazil.

Complete genome analyses of G4P[6] rotavirus detected in Argentinean children with diarrhoea provides evidence of interspecies transmission from swine.

Rotaviruses are dynamic pathogens that have been shown to infect multiple species. In 2006, two G4P[6] rotavirus strains with porcine characteristics were detected in Santa Fe, Argentina. To further characterize and determine the origin of these strains, nearly the full length of their genome was sequenced. While most of the genome segments were from porcine origin, the two strains grouped in different phylogenetic clusters in five out of the 11 genes, suggesting two independent interspecies transmission events. This study expands our knowledge of G4 rotavirus and reinforces the use of complete genome analyses as a key tool for diversity and evolution mechanicisms.

Phylogenetic analysis of G1P[6] group A rotavirus strains detected in Northeast Brazilian children fully vaccinated with Rotarix™.

In 2009 the World Health Organization recommended the use of group A rotavirus (RVA) vaccines in all national immunization programs (NIPs) in order to control severe RVA gastroenteritis disease. In Brazil, Rotarix™ was introduced in the NIP in March 2006, and a significant reduction in mortality rates among children ≤ 5 years old was observed, especially in the Northern and Northeastern Brazil. In the current study the 11 gene segments of six Brazilian G1P[6] RVA strains, isolated in 2009 and 2010 from vaccinated children, were analyzed in order to investigate if the genetic composition of these strains might help to elucidate why they were able to cause acute gastroenteritis in vaccinated children. All six Brazilian RVA strains revealed a complete Wa-like genotype constellation: G1-P[6]-I1-R1-C1-M1-A1-N1-T1-E1-H1. Phylogenetic analysis showed that all six strains were nearly identical and showed a close genetic relationship with contemporary typical human Wa-like RVA strains. These results suggests that the fact that these strains were able to cause acute gastroenteritis in vaccinated children is likely not due to the genetic background of the strains, but rather to other factors such as host relating factors, co-infecting pathogens or vaccine efficacy. P[6] RVA strains are detected rather occasionally in humans in most regions of the world, except for South Asia and Sub-Saharan Africa. However, recently two studies conducted in Brazil showed the circulation of G12P[6] and G2P[6]. This is the first report on the detection and complete genome analyses of G1P[6] RVA strains in Brazil. Surveillance studies will be crucial to further investigate the prevalence of this genotype in the Brazilian population, and the efficacy of current licensed vaccines, which do not contain the P[6] genotype.