David R. Brown, PhD

1.  IntroductionMorphine and other opioid receptor agonists alter systemic innate and adaptive immune responses and increase host susceptibility to infection [1]. For example, impairments in neutrophil function, macrophage phagocytosis, T lymphocyte cytokine production, and B cell antigen presentation occur after exposure to morphine. In some cases, these effects are mediated through mu- ...

The intestinal mucosa possesses an extensive surface area and is exposed to a large and diverse number of microorganisms and potentially antigenic proteins throughout the lifetime of a pig. The mucosal epithelium is capable of assimilating vital nutrients while simultaneously excluding ingested pathogens and other harmful materials. In mature swine, an array of gastrointestinal defense processes a ...

With its extensive surface area and critical role in the absorption of nutrients, the intestinal mucosa is exposed to a great quantity and variety of potentially antigenic substances throughout the lifetime of the pig. In defending the mucosal surface, the intestine must clearly distinguish between harmless and harmful foreign antigens that are introduced during the process of feeding and drinking ...

Meningitis is a serious complication of Streptococcus suisbacteremia in young piglets. This microorganism is also an emerging human pathogen that has been recently implicated in a case of meningitis in a swine handler (Wertheim et al., 2009; Fowler et al., 2013). In order to access and infect the brain meninges, blood-borne S. suis must penetrate the blood-brain barrier of affected animals or huma ...