Rare AU-1-Like G3P[9] Human Rotaviruses with a Kun-Like NSP4 Gene Detected in Children with Diarrhea in Italy

Abstract

Three G3P[9] rotaviruses, detected in children hospitalized with gastroenteritis in Palermo, Italy, were found to be genetically related to strains of either human or feline origin in the VP7, VP4, and VP6 genes. In contrast, in the NSP4 gene the viruses resembled G2P[4] human strains, suggesting a reassortment between AU-1-like and Kun-like strains.Group A rotaviruses are a major cause of acute gastroenteritis in humans and animals (14). The rotavirus genome is composed of 11 segments of double-stranded RNA (dsRNA) (4). The pattern of migration of the dsRNA by polyacrylamide gel electrophoresis (PAGE) allows the distinction of a long, short, or supershort electropherotype (e-type) (4). The viruses are classified as G and P types on the basis of the outer capsid proteins VP7 and VP4, respectively (4). Of the 15 G types and the 27 P types, 5 G types (types G1 to G4 and G9) and three P types (types P[4], P[6], and P[8]) appear to be common in human rotaviruses (21). On the basis of their reactivities to VP6-specific monoclonal antibodies, group A rotaviruses are classified into types SGI, SGII, SGI ϩ SGII, and SG-non I-non II (4). The majority of SGI and SGII animal rotavirus strains and SGII human rotavirus strains display a long e-type of migration of the 11 dsRNA gene segments, while almost all SGI human rotaviruses possess a short e-type (14). The nonstructural protein NSP4 is able to induce diarrhea in experimental rodents through a Ca 2ϩ -dependent signaling pathway (18). Passively acquired antibodies to NSP4 appear to prevent watery diarrhea in mice (2), and this sets NSP4 as a potential vaccine target. Six NSP4 genotypes (genotypes A to F) have been established in group A rotaviruses. In humans, NSP4 genotypes A (Kun-like) and B (Wa-like) are common. Genotype C (AU-1-like) is common in feline and canine strains but is infrequent in human rotaviruses (3).The G3 VP7 specificity has been identified in rotavirus strains from almost all susceptible animal species (4). In humans, G3 rotaviruses are usually associated with the P[8] VP4 genotype and, more rarely, with the P[9] genotype (10,15,21). Conversely, the G3P[9] combination is common in feline rotaviruses (11). Interspecies infections between animals and humans can be revealed by the detection of strains with unexpected antigenic and genetic features. The first human G3P [9] rotavirus strain, strain AU-1, was isolated in Israel in 1982. The strain displayed animal-like features (a long e-type in conjunction with SGI specificity) and was shown by RNA-RNA hybridization to be closely related to feline rotaviruses (19).Uninterrupted surveillance activity for rotaviruses has been conducted in Palermo, Italy, since the mid-1980s. Between 1985 and 2005, 1,547 rotavirus-positive samples were collected and characterized either antigenically or genetically to predict the VP7, VP4, and VP6 specificities and the genome pattern. Three strains (strains PAF96/94, PAH136/96, and PAI58/96) displayed animal strain-like features, since they possessed a long e-type by PAGE an...

Multiple‐gene characterization of rotavirus strains: Evidence of genetic linkage among the VP7‐, VP4‐, VP6‐, and NSP4‐encoding genes

“…Likewise, strains R113 and R142 presented human-feline-canine G9-P[9]-I1-E2 and G3-P[9]-I2-E2 profiles, respectively. This unusual G3-P[9]-E2 profile has been observed in three rotavirus strains detected in Italy [De Grazia et al, 2008] and suggests a reassortment between AU-1-like and Kunlike strains. Three strains possessed the profiles G3-P[9]-I1-E1 (R52 and R56) and G1-P[9]-I1-E1 (R70), suggesting a reassortment between AU-1-like and Walike strains.…”

“…The I3-E3 profile is generally associated with feline-canine rotavirus strains, which are usually related to genotypes G3-P[3] or P[9] [Tsugawa and Hoshino, 2008]. Few rotavirus reassorted strains bearing human-felinecanine specificity have been reported [Taniguchi et al, 1989;Santos et al, 2001;Khamrin et al, 2007;De Grazia et al, 2008]. The human G3-P[9]-I3-E3 prototype strain AU-1 has been demonstrated to be closely related to feline-canine rotavirus [Nakagomi et al, 1987;Nakagomi and Nakagomi, 1989].…”

Severe gastroenteritis associated with G3P[9] rotavirus in Taiwan

“…In this study, we found that G3P [9] strains caused severe infection in two patients that required hospital treatment. This is consistent with the scarce data in the literature [13][14][15][16][17]22], indicating that G3P [9] strains cannot be considered as less virulent than other community strains. These findings could have implications in the vaccination era.…”

Molecular Epidemiology of Rotavirus in Cats in the United Kingdom

“…Human RVAs with genetic homology to feline RVAs have been isolated from widespread geographical locations, including Japan (12,13), Israel (14,15), Tunisia (16), and the United States (17). Additionally, putative human/feline reassortant rotaviruses have been identified in children in Italy (18).…”