Plasmodium infections result in clinical presentations that range from asymptomatic to severe malaria, resulting in ∼1 million deaths annually. Despite this toll on humanity, the factors that determine disease severity remain poorly understood. Here, we show that the gut microbiota of mice influences the pathogenesis of malaria. Genetically similar mice from different commercial vendors, which exhibited differences in their gut bacterial community, had significant differences in parasite burden and mortality after infection with multiple Plasmodium species. Germfree mice that received cecal content transplants from "resistant" or "susceptible" mice had low and high parasite burdens, respectively, demonstrating the gut microbiota shaped the severity of malaria. Among differences in the gut flora were increased abundances of Lactobacillus and Bifidobacterium in resistant mice. Susceptible mice treated with antibiotics followed by yogurt made from these bacterial genera displayed a decreased parasite burden. Consistent with differences in parasite burden, resistant mice exhibited an elevated humoral immune response compared with susceptible mice. Collectively, these results identify the composition of the gut microbiota as a previously unidentified risk factor for severe malaria and modulation of the gut microbiota (e.g., probiotics) as a potential treatment to decrease parasite burden.

Ocular infection with Herpes Simplex Virus causes a chronic T-cell mediated inflammatory lesion in the cornea. Lesion severity is affected by the balance of different CD4 T-cell subsets with greater severity occurring when the activity of regulatory T-cells is compromised. In the present report, fate-mapping mice were used to assess the stability of Treg function in ocular lesions. We show that cells that were once FoxP3+ functional Treg may lose FoxP3 and become Th1 cells which themselves could contribute to lesion expression. The instability mostly occurred with IL-2 receptor low Treg and was shown to be in part the consequence of exposure to IL-12. Lastly, in-vitro generated iTreg were shown to be highly plastic and capable of inducing SK when adoptively transferred into Rag1−/− mice, with 95% of iTreg converting into ex-Treg in the cornea. This plasticity of iTreg could be prevented when they were generated in the presence of Vitamin-C and Retinoic acid. Importantly, adoptive transfer of these stabilized iTreg to HSV-1 infected mice more effectively prevented the development of SK lesions than did the control iTreg. Our results demonstrate that CD25lo Treg and iTreg instability occurs during a viral immuno-inflammatory lesion and that its control may help avoid lesion chronicity.

Research has shown that some bariatric patients overestimate post-surgical exercise levels, while others struggle with negative cognitions and follow-through on intentions to exercise; however, little exists on specific barriers affecting bariatric patients' post-surgical exercise behaviors. Considering that regular exercise is a predictor of weight loss maintenance, further research is warranted. Survey methodology was utilized to assess post-operative exercise barriers as well as beneficial post-surgical exercise services among a sample of bariatric patients solicited from an online support website. Qualitative assessment of responses was completed using inductive content analysis. Higher-order themes for exercise barriers included internal, external, and no barriers; generic categories determined for internal barriers included motivational and physical barriers. Of the participants, 78% reported at least one internal motivational barrier, and the most frequently reported subcategorical barrier was time (28%); physical barriers were reported related to surgery (9%) or other chronic conditions (19%). Higher-order themes for exercise services included positive descriptions such as benefits from exercise prescription as well as the importance of facilities and individuals, while negative descriptions included no services available or services that were unhelpful. Participants cited the benefit of community-based facilities, so providers might consider partnering with local professionals to deliver exercise services. Staff should be aware of physical barriers specific to bariatric populations including issues with post-surgical stamina and chronic comorbid conditions in order to provide appropriate exercise prescription. In addition, as motivational and time barriers occur frequently, providers should be well-trained on how to help patients overcome these impediments to exercise maintenance.

A novel Group A rotavirus, first identified clinically in racing, feral and fancy pigeons

BackgroundCanids are definitive hosts of the apicomplexan parasite Neospora caninum, the leading cause of abortion in cattle worldwide. For horizontal transmission from canids to occur, oocysts of N. caninum must be shed by the definitive host into the environment of susceptible intermediate hosts such as cattle. The purpose of this study was to determine the prevalence of N. caninum in canids in Victoria, Australia’s leading dairy producing state.Results Neospora-like oocysts were observed in 8% (18/234) of faecal samples from wild dogs, domestic dogs and red foxes from Victoria, Australia. However, none tested positive for N. caninum DNA using a quantitative PCR. In a separate sample population, blood sera from 483 domestic dogs were tested for anti-N. caninum antibodies using competitive ELISA. A subset of cELISA samples were re-tested using indirect fluorescence antibody test (IFAT). A seroprevalence of 29.8% (144/483; 95% CI: 11.7–47.8%) was calculated when using cELISA; whereas it was 32.9% (27/80; 95% CI: 15.8–51.8%) using IFAT. Potential risk factors were evaluated using univariable analyses and then assessed in separate multivariable models. Using ‘aged’ dogs as a reference, the seroprevalence of ‘adolescent’ and ‘adult’ dogs was 88% (P = 0.05) and 91% (P = 0.08), respectively, indicating seroprevalence increases with age. There was a 19% higher likelihood of infection in rural locations (P = 0.10) relative to urban areas. Jack Russell Terriers had a 22% higher risk of a cELISA-positive result (P = 0.05) regardless of geographical location, age or sex.ConclusionThese results demonstrate that exposure to N. caninum in domestic dogs is widespread in Victoria, although faecal oocyst shedding is infrequent. Our results indicate increased N. caninum seroprevalance status in dogs over the past two decades. The results imply that dogs get either exposed to the infected meat more frequently or that vertical dam to foetus transmission is more frequent than previously thought. Our study calls for re-evaluation of historical N. caninum seroprevalance studies, because the attitude to dog diet changes.Electronic supplementary materialThe online version of this article (10.1186/s13071-017-2464-2) contains supplementary material, which is available to authorized users.