A longitudinal cohort study in calves evaluated for rotavirus infections from 1 to 12 months of age by sequential serological assays

Predominance of genotype P[9]G3 in rotavirus gastroenteritis in Polish children

INTRODUCTION

Rotavirus (RV) infection is the most common cause of gastroenteritis in children. This paper identifies the most common genotypes of rotaviruses isolated from children hospitalized with gastroenteritis and attempts to determine any relationship between infection with a certain rotavirus genotype.

MATERIAL AND METHODS

The investigated group consisted of 68 consecutive children with rotavirus gastroenteritis (confirmed by an agglutination test). Rotavirus genotype was determined in stool samples obtained from each child.

RESULTS

The P[9]VP4 genotype was observed in 41/61 positive samples (over 67.2%) that were permanently associated with the G3 VP7 genotype. Moreover, G3 was determined as the most commonly isolated G type (77.94%). As well as the P[9]G3 type, G3 was also found in the P[4] type (5 cases). Twenty-six out of 61 (42.6%) children in whom rotavirus genotype was determined were co-infected with pathogenic bacteria. No statistical correlation was observed between rotavirus P[9]G3 gastroenteritis and digestive tract co-infection with pathogenic bacteria (p > 0.05). Elevated ALT activity was found in 34/59 (57.6%) cases of rotavirus gastroenteritis. Elevated ALT serum level was found to correlate with P[9]G3 rotavirus genotype but concomitant infections did not.

CONCLUSIONS

The most common genotype of rotaviruses observed in our group of children, P[9]G3, has rarely been described. Co-infection of the digestive tract with pathogenic bacteria and elevated serum ALT concentrations were found to be the most frequent phenomena. A correlation between P[9]G3 rotavirus genotype and elevated serum ALT level was found, but no significant relationship was identified between concomitant infections and P[9]G3 genotype.

G8P[6] rotaviruses isolated from Amerindian children in Mato Grosso do Sul, Brazil, during 2009: close relationship of the G and P genes with those of bovine and bat strains

During the 2009 national group A rotavirus (RVA) surveillance, five unusual strains of the human G8P[6] genotype were detected in Brazilian indian children with acute gastroenteritis. The aim of this study was to carry out sequence analysis of the two outer capsid proteins (VP4 and VP7) and the inner capsid protein (VP6) of the G8P[6] strains detected in order to provide further information on the genetic relationship between human and animal RVA. A total of 68 stool samples, collected in Mato Grosso do Sul during 2009, were tested for RVA using ELISA, following by reverse transcriptase-PCR and sequencing. RVA infection was detected in 7.3% of samples (5/68). The IAL-RN376 G8 sequence shares a clade with bovine and human strains, displaying highest nucleotide identity to African human strains DRC86 and DRC88, followed by African bovine strain NGRBg8. IAL-RN376 and IAL-RN377 P[6] sequences showed highest identity to human strain R330 from Ireland, and a close genetic relationship to African fruit bat RVA strain KE4852/07. Strains IAL-RN376 and IAL-RN377 display genogroup I VP6 specificity and the I2 genotype, and share high nucleotide identities with human strains B1711, 272-BF and 06-242, and moderate identities with bovine (RUBV81, 86 and KJ9-1) and porcine (HP140) strains. This study suggested that a reassortment between bovine and bat RVA strains could have occurred in animal host(s) preceding the transmission to humans. In the indigenous population, zoonotic transmission is probably fairly frequent as the inhabitants live in close contact with animals under conditions of poor hygiene.

Resistance to rotavirus infection in adult volunteers challenged with a virulent G1P1A[8] virus correlated with serum immunoglobulin G antibodies to homotypic viral proteins 7 and 4

BACKGROUND

In a study performed in 1983, 18 adult volunteers received oral challenge with the virulent human rotavirus strain D (G1P1A[8],NSP4[B]). To identify correlates of resistance to rotavirus infection, we analyzed levels of serum immunoglobulin (Ig) A and IgG antibodies to various rotaviral antigens in 16 of the 18 volunteers.

METHODS

We used immunocytochemical assays that involved a total of 16 different recombinant baculoviruses, with each baculovirus expressing one of the following major serotype/genotype rotavirus proteins for the serologic assays: (1) viral protein (VP) 4 with P1A[8], P1B[4], P2A[6], P3[9], or P4[10] specificity; (2) VP7 with G1-G4 or G9 specificity; and (3) nonstructural viral protein (NSP) 4 with genotype A, B, C, or D specificity.

RESULTS

The prechallenge titers of IgG antibody to VP7 types G1, G3, G4, and G9; VP4 types P1A[8], P1B[4], P2A[6], and P4[10]; and NSP4 type [A] in the group of noninfected volunteers (n = 11) were significantly higher than those in the group of infected volunteers (n = 5; of these 5 volunteers, 4 were symptomatically infected). Moreover, logistic regression analysis showed that resistance to rotavirus infection most closely correlated with higher prechallenge titers of IgG antibody to homotypic VP7 (G1) and VP4 (P1A[8]).

CONCLUSIONS

These results suggest that protection against rotavirus infection and disease is primarily VP7/VP4 homotypic and, to a lesser degree, heterotypic.

Genomic characterization of nontypeable rotaviruses and detection of a rare G8 strain in Delhi, India

In the present investigation we molecularly characterized nontypeable rotavirus strains previously identified during surveillance in New Delhi, India. The majority of strains were demonstrated to belong to genotype G1 (54.5%) or P[8] (77.8%) on the basis of nucleotide sequencing of fragments from their VP7 and VP4 genes. The other genotypes detected included G2, G8, G9, G12, and P[4]. A G8P[6] strain, strain DS108, was detected for the first time in northern India. The VP7 gene of DS108 was most homologous with the VP7 gene of a bovine G8 strain, strain A5 (98.9%), indicating its bovine parentage. In contrast, the VP4 gene had a high degree of nucleotide sequence homology (92.9% to 99.1%) with the VP4 genes of human P[6] strains. The VP6 gene and nonstructural genes (NSP1 to NSP3 and NSP5) were most homologous with the VP6 gene and nonstructural genes of human rotaviruses belonging to the DS1 genogroup. Interestingly, the NSP4 gene of DS108 clustered within genotype E6 that until now had only two representative strains, both with G12P[6] specificity (strains RV176-00 and N26-02). Together, these results indicate that G8 strain DS108 belongs to the DS1 genogroup and could be the result of the acquisition of the VP7, VP4, and NSP4 genes by a human G2P[4] strain from more than one donor, similar to the evolution of G12P[6] strain RV176-00. The present study highlights the importance of characterizing multiple genes of nontypeable rotavirus strains to detect novel strains and get a more complete picture of rotavirus evolution.