Pair feeding of control mice, instead of ad libitum access to an isocaloric control diet, would have further strengthened our design by controlling for potential effects of amount of rations consumed. We predicted that undernourished mice would be more susceptible to rotavirus replication and have more severe disease, however this was clearly not the case. As previously observed by Offor et al. in malnourished suckling mice learn more [36], we found accelerated rotavirus shedding in undernourished mice, however both undernourished and nourished animals were able to clear rotavirus effectively. These later results stand in contrast to findings

by Guerrant and co-workers that report more severe disease and exacerbation of malnutrition when undernourished mice are infected with Cryptosporidium [37], Giardia, [38] and enteroaggregative E. coli [39]. Of note, by choosing to challenge adult mice, our models were better designed to examine rotavirus infection and shedding rather than frank diarrhea—a response limited to EDIM infection of young mice. Additional host factors that might account for GSK1349572 in vivo the divergence of our findings from other published mouse models of malnutrition and gut infection include mouse strain and the method by which undernutrition is induced, e.g., caloric restriction vs. multideficient diets vs. timed separations of pups

from dams. To our knowledge, the “vicious cycle” of diarrhea and undernutrition has not yet been definitively recapitulated in rodent models of viral diarrhea. In addition, the findings of our mouse study parallel results of a large case–control study of diarrhea hospitalizations in Bangladesh, which found that children admitted with rotavirus-positive diarrhea had better Histamine H2 receptor nutritional status than children admitted for parasitic or bacteria-associated diarrheal illnesses [40]. Another recent mouse study also

found that underweight mice had one less day of diarrhea as compared to their normal-weight and overweight counterparts [41]. The current animal data, together with previously published clinical findings, suggest that undernutrition may indeed be an important risk factor for initial or even repeat rotavirus infections, but that mild-to-moderate malnutrition is not a significant contributor to the severity of rotavirus infections. When nourished and undernourished mice were vaccinated with RRV, we found no group differences in viral clearance following EDIM challenge; however, we did detect group differences in serum and stool antibody responses. Lower levels of total stool IgA in RBD vaccinated mice compared to CD mice might be explained by a deficiency of mucosal IgA production or transport secondary to a delay in maturation of the secretory IgA system due to protein malnutrition, as reported by Green and Heyworth [42]. Our finding of increased serum IgA and IgG in RBD-fed mice is also supported by the work of Neumann et al.