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Group A rotaviruses (RV-A) are the leading cause of viral gastroenteritis in children worldwide and genotype G9P[8] is one of the five most common genotypes detected in humans. In order to gain insight into the degree of genetic variability of G9P [8] HHS Public Access BackgroundChildhood mortality has been declining worldwide as a result of socioeconomic development and implementation of prevention and survival interventions (Claeson et al., 2000). Group A rotaviruses (RV-A) are the main etiologic agent of acute gastroenteritis in infants and young children worldwide (Estes and Kapikian, 2007) and an estimated 453,000 children aged <5 years die from rotavirus diarrhea each year, with >85% of these deaths occurring in low-income countries of Africa and Asia (Parashar et al., 2009;Tate et al., 2011). Rotaviruses belong to the family Reoviridae, and the rotavirus genome consists of 11 double-stranded RNA gene segments that encode six structural (VP) and six non-structural proteins (NSP). Based on the two genes that encode the outer capsid proteins, VP4 (P-type) and VP7 (G-type), a widely used binary classification system was established for RV-A (Estes and Kapikian, 2007). This system has been recently standardized and extended to all 11 genes (Matthijnssens et al., 2008b). To date, at least 27 G, 35 P, 16 I, 9 R, 9 C, 8 M, 16 A, 9 N, 12 T, 14 E and 11 H genotypes have been identified based on the eleven rotavirus A genes (Esona et al., 2010b;Matthijnssens et al., 2011). In humans, at least five RV-A G types (G1-G4 and G9), and two common P types (P[8] and P[4]) circulate worldwide (Banyai et al., 2012;Gentsch et al., 2005;Santos and Hoshino, 2005). G9 strains emerged in 1990s, and there has been a global description of the appearance and dominance of this genotype (Gentsch et al., 2005;Laird et al., 2003;Matthijnssens et al., 2009;Santos and Hoshino, 2005). Genotype G9 strains with a Wa-like or a DS-1-like genomic configuration or a mixture thereof have been detected sporadically in localized outbreaks (Page et al., 2010). In Cameroon, the first molecular identification of genotype G9 in human samples was reported in a study conducted by colleagues in 2003 (Steele andIvanoff, 2003). At least seven major phylogenetic lineages and eleven minor lineages within G9 VP7 genes have been described (Phan et al., 2007;Wu et al., 2011). A molecular evolutionary analysis study utilizing Bayesian inference supported the idea that one single sub-lineage introduced in the 1980s was responsible for all the worldwide spread of G9 in the 1990s .In order to gain insight into the degree of genetic variability of G9P [8] Viral RNA extraction, amplification, and sequencingViral RNA from each of the 15 specimens was extracted from a 10% stool suspension made from 0.1 g or 100 μl stool in 2 ml of a 1:1 Vertrel/Water solution using either a commercial RNA extraction kit (NucliSens automated extractor, BIOMERIEUX, Durham, NC) according to the protocol specified by the manufacturer or a silica binding method described pr...

Surveillance for rotavirus-associated diarrhea after implementation of rotavirus vaccination can assess vaccine effectiveness and identify disease-associated genotypes. During active vaccine postlicensure surveillance in the United States, we found a novel rotavirus genotype, G14P[24], in a stool sample from a child who had diarrhea. Unusual rotavirus strains may become more prevalent after vaccine implementation.

We recently reported a lack of interference between inactivated rotavirus vaccine (IRV) and inactivated poliovirus vaccine (IPV) and their potential dose sparing when the two vaccines were administered intramuscularly either in combination or standalone in rats and guinea pigs. In the present study, we optimized the formulations of both vaccines and investigated the feasibility of manufacturing a combined IRV-IPV dissolving microneedle patch (dMNP), assessing its compatibility and immunogenicity in rats. Our results showed that IRV delivered by dMNP alone or in combination with IPV induced similar levels of RV-specific IgG and neutralizing antibody. Likewise, IPV delivered by dMNP alone or in combination with IRV induced comparable levels of neutralizing antibody of poliovirus types 1, 2, and 3. We further demonstrated high stability of IRV-dMNP at 5, 25, and 40 °C and IPV-dMNP at 5 and 25 °C, and found that three doses of IRV or IPV when co-administered at a quarter dose was as potent as a full target dose in inducing neutralizing antibodies against corresponding rotavirus or poliovirus. We conclude that IRV-IPV dMNP did not interfere with each other in triggering an immunologic response and were highly immunogenic in rats. Our findings support the further development of this innovative approach to deliver a novel combination vaccine against rotavirus and poliovirus in children throughout the world.

Group C rotavirus (GpC RV) is a causative agent of acute gastroenteritis in children and adults. We expressed the three major capsid proteins VP2, VP6 and VP7 of human GpC RV in baculovirus and demonstrated the self-assembly of VP2/6/7 or VP6/7 virus-like particles (VLPs) in insect cells. We examined a number of parameters, including the kinetics of protein synthesis in different cell lines and media, to optimize the most favorable conditions for the synthesis of recombinant viral proteins and the production of VLPs in Sf9 cells. Hyperimmune serum to VP2/6/7 and VP6/7 VLPs recognized individual recombinant proteins of human GpC RV by Western blot analysis. This serum also showed specific reactivities with the corresponding GpC VLPs but not GpA RV by using immune electron microscopy (IEM) and enzyme immunoassay (EIA). The ability to produce an unlimited amount of GpC RV antigen and the availability of high quality antibody will allow us to develop sensitive and specific diagnostic assays to better determine the epidemiology and disease burden of GpC RV in humans.

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