A Ligated Intestinal Loop Model in Anesthetized Specific Pathogen Free Chickens to Study Clostridium Perfringens Virulence

Evolution of Bacterial Vaccines: from Pasteur to Genomics

Vaccination against bacteria offers its share of challenges, and important progress has been made in recent years. Conventional vaccinology has protected poultry for decades with killed and attenuated bacterial vaccines. Because of the limitations of these vaccines, and given the latest technological advances, other types of vaccines were developed using various strategies. New vaccines are also being commercialized using viral or bacterial recombinant vectors or in the form of subunit vaccines developed by a genomic approach and bioinformatics analyses. As bacteria are forever-evolving microorganisms, there is no doubt that vaccine strategies preventing bacterial diseases will also evolve and that new generations of vaccines are yet to come.

Advances, challenges and future applications of avian intestinal in vitro models

There is a rapidly growing interest in how the avian intestine is affected by dietary components and probiotic microorganisms, as well as its role in the spread of infectious diseases in both the developing and developed world. A paucity of physiologically relevant models has limited research in this essential field of poultry gut health and led to an over-reliance on the use of live birds for experiments. The intestine is characterized by a complex cellular composition with numerous functions, unique dynamic locations and interdependencies making this organ challenging to recreate in vitro. This review illustrates the in vitro tools that aim to recapitulate this intestinal environment; from the simplest cell lines, which mimic select features of the intestine but lack anatomical and physiological complexity, to the more recently developed complex 3D enteroids, which recreate more of the intestine's intricate microanatomy, heterogeneous cell populations and signalling gradients. We highlight the benefits and limitations of in vitro intestinal models and describe their current applications and future prospective utilizations in intestinal biology and pathology research. We also describe the scope to improve on the current systems to include, for example, microbiota and a dynamic mechanical environment, vital components which enable the intestine to develop and maintain homeostasis in vivo. As this review explains, no one model is perfect, but the key to choosing a model or combination of models is to carefully consider the purpose or scientific question.

Using a ligate intestinal loop mouse model to investigate Clostridioides difficile adherence to the intestinal mucosa in aged mice

Interaction of Clostridioides difficile spores with the intestinal mucosa contributes to the persistence and recurrence of the infection. Advanced age is one of the main risk factors for C. difficile infection and recurrence of the disease. However, interaction of C. difficile spores with the intestinal mucosa during aging has not been evaluated. In the present work, using intestinal ligated loop technique in a mouse model, we analyzed C. difficile spore adherence and internalization to the ileum and colonic mucosa during aging. Additionally, we provide visual documentation of the critical steps of the procedure. Consequently, our data suggest that spore internalization in the ileum and colonic mucosa is higher in elderly mice rather than adults or young mice. Also, our data suggest that spore adherence to the ileum and colonic mucosa decreases with aging.