The higher prevalence of inflammatory bowel disease (IBD) in Western countries points to Western diet as a possible IBD risk factor. High sugar, which is linked to many noncommunicable diseases, is a hallmark of the Western diet, but its role in IBD remains unknown. Here, we studied the effects of simple sugars such as glucose and fructose on colitis pathogenesis in wild-type and Il10−/− mice. Wild-type mice fed 10% glucose in drinking water or high-glucose diet developed severe colitis induced by dextran sulfate sodium. High-glucose–fed Il10−/− mice also developed a worsened colitis compared to glucose-untreated Il10−/− mice. Short-term intake of high glucose or fructose did not trigger inflammatory responses in healthy gut but markedly altered gut microbiota composition. In particular, the abundance of the mucus-degrading bacteria Akkermansia muciniphila and Bacteroides fragilis was increased. Consistently, bacteria-derived mucolytic enzymes were enriched leading to erosion of the colonic mucus layer of sugar-fed wild-type and Il10−/− mice. Sugar-induced exacerbation of colitis was not observed when mice were treated with antibiotics or maintained in a germ-free environment, suggesting that altered microbiota played a critical role in sugar-induced colitis pathogenesis. Furthermore, germ-free mice colonized with microbiota from sugar-treated mice showed increased colitis susceptibility. Together, these data suggest that intake of simple sugars predisposes to colitis and enhances its pathogenesis via modulation of gut microbiota in mice.

The underlying molecular mechanism of chlorosis, a typical symptom of plant viral diseases, remains poorly understood. To establish an experimental system to determine the molecular changes during chlorosis, especially in the early phase, we generated transgenic tobacco plants expressing Cauliflower mosaic virus Transactivator/viroplasmin (Tav) under the control of a chemically inducible promoter. Induction of Tav resulted in visible chlorosis in ten days, a statistically significant decrease in chlorophyll content in two days, decreased expression of chloroplast protein genes, and abnormal thylakoid stacks, indicating that this system reproduces the common features of chlorosis in virus-infected plants.

Bacterial leaf scorch, caused by Xylella fastidiosa , is a major threat to blueberry production in the southeastern United States. Management of this devastating disease is challenging and often requires early detection of the pathogen to reduce major loss. There are several different molecular and serological detection methods available to identify the pathogen. Knowing the efficiency and suitability of these detection techniques for application in both field and laboratory conditions is important when selecting the appropriate detection tool. Here, we compared the efficiency and the functionality of four different molecular detection techniques (PCR, real-time PCR, LAMP and AmplifyRP® Acceler8™) and one serological detection technique (DAS-ELISA). The most sensitive method was found to be real-time PCR with the detection limit of 25 fg of DNA molecules per reaction (≈9 genome copies), followed by LAMP at 250 fg per reaction (≈90 copies), AmplifyRP® Acceler8™ at 1 pg per reaction (≈350 copies), conventional PCR with nearly 1.25 pg per reaction (≈ 440 copies) and DAS-ELISA with 1x10 5 cfu/mL of Xylella fastidiosa . Validation between assays with 10 experimental samples gave consistent results beyond the variation of the detection limit. Considering robustness, portability, and cost, LAMP and AmplifyRP® Acceler8™ were not only the fastest methods but also portable to the field and didn’t require any skilled labor to carry out. Among those two, AmplifyRP® Acceler8™ was faster but more expensive and less sensitive than LAMP. On the other hand, real-time PCR was the most sensitive assay and required comparatively lesser time than C-PCR and DAS-ELISA, which were the least sensitive assays in this study, but all three assays are not portable and needed skilled labor to proceed. These findings should enable growers, agents, and diagnosticians to make informed decisions regarding the selection of an appropriate diagnostic tool for X . fastidiosa on blueberry.

A loop-mediated isothermal amplification (LAMP) assay was developed for simple, rapid and efficient detection of Cucurbit leaf crumple virus (CuLCrV), one of the most important begomoviruses that infects cucurbits worldwide. A set of six specific primers targeting a total 240 nt sequence regions in the DNA A of CuLCrV were designed and synthesized for detection of CuLCrV from infected leaf tissues using real-time LAMP amplification with the Genie® III system, which was further confirmed by gel electrophoresis and SYBR™ Green I DNA staining for visual observation. The optimum reaction temperature and time were determined, and no cross-reactivity was seen with other begomoviruses. The LAMP assay could amplify CuLCrV from a mixed virus assay. The sensitivity assay demonstrated that the LAMP reaction was more sensitive than conventional PCR, but less sensitive than qPCR. However, it was simpler and faster than the other assays evaluated. The LAMP assay also amplified CuLCrV-infected symptomatic and asymptomatic samples more efficiently than PCR. Successful LAMP amplification was observed in mixed virus-infected field samples. This simple, rapid, and sensitive method has the capacity to detect CuLCrV in samples collected in the field and is therefore suitable for early detection of the disease to reduce the risk of epidemics.

The intestine displays an architecture of repetitive crypt structures consisting of different types of epithelial cells, lamina propia containing immune cells, and stroma. All of these heterogeneous cells contribute to intestinal homeostasis and participate in antimicrobial host defense. Therefore, identifying a surrogate model for studying immune response and antimicrobial activity of the intestine in an in vitro setting is extremely challenging. In vitro studies using immortalized intestinal epithelial cell lines or even primary crypt organoid culture do not represent the exact physiology of normal intestine and its microenvironment. Here, we discuss a method of culturing mouse colon tissue in a culture dish and how this ex vivo organ culture system can be implemented in studies related to antimicrobial host defense responses. In representative experiments, we showed that colons in organ culture express antimicrobial peptides in response to exogenous IL-1β and IL-18. Further, the antimicrobial effector molecules produced by the colon tissues in the organ culture efficiently kill Escherichia coli in vitro. This approach, therefore, can be utilized to dissect the role of pathogen- and danger-associated molecular patterns and their cellular receptors in regulating intestinal innate immune responses and antimicrobial host defense responses.