Infections and infestations of the gastrointestinal tract. Part 1: bacterial, viral and fungal infections

Recent Advances in Pharmaceutical Approaches of Antimicrobial Agents for Selective Delivery in Various Administration Routes

Globally, the increase of pathogenic bacteria with antibiotic-resistant characteristics has become a critical challenge in medical treatment. The misuse of conventional antibiotics to treat an infectious disease often results in increased resistance and a scarcity of effective antimicrobials to be used in the future against the organisms. Here, we discuss the rise of antimicrobial resistance (AMR) and the need to combat it through the discovery of new synthetic or naturally occurring antibacterial compounds, as well as insights into the application of various drug delivery approaches delivered via various routes compared to conventional delivery systems. AMR-related infectious diseases are also discussed, as is the efficiency of various delivery systems. Future considerations in developing highly effective antimicrobial delivery devices to address antibiotic resistance are also presented here, especially on the smart delivery system of antibiotics.

Transient Small Bowel Angio-oedema Secondary to Intravenous Iodinated Contrast Medium

We report the clinical profile and computed tomography (CT) findings of a rare case of transient angio-edema of the small bowel following intravenous administration of non-ionic iodinated contrast material in a 36-year-old woman. The pre-contrast CT showed normal small bowel and large bowel wall thickness. Findings included long segment, circumferential bowel wall thickening involving the duodenum, jejunum, and almost the entire ileum on CT scan obtained following the intravenous contrast material injection. The large bowel wall appeared normal in post contrast images also. There was no mesenteric fat stranding, ascites or significant lymphadenopathy. This entity, like most contrast-induced adverse reactions, has a favorable clinical outcome with aggressive clinical monitoring and supportive measures.

Modulation of Intestinal Barrier, Inflammatory Response, and Gut Microbiota by Pediococcus pentosaceus zy-B Alleviates Vibrio parahaemolyticus Infection in C57BL/6J Mice

Modulation of the intestinal barrier, inflammation, and gut microbiota by Pediococcus pentosaceus zy-B (zy-B) in Vibrio parahaemolyticus (Vp)-infected C57BL/6J mice was studied. Mice intragastrically pretreated with 10⁸ colony-forming units (CFU) zy-B significantly alleviated Vp infection as evidenced by maintaining body weight and reduced disease activity index score and intestine ratio. In addition, zy-B reduced the Vp load in the ileum and cecum, significantly reduced the load in the colon, prevented colonic atrophy, and strengthened mucosal integrity. Mechanistically, zy-B ameliorated intestinal barrier dysfunction by upregulating tight junction protein expression, which in turn reduced the lipopolysaccharide, d-lactic acid (d-LA), and diamine oxidase concentrations and downregulated the cannabinoid receptor 1 (CB1) and CB2 mRNA expressions. Moreover, zy-B systemically reduced inflammation by decreasing interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α levels, and increased interleukin-10 (IL-10), immunoglobulin M (IgM), and immunoglobulin G (IgG) levels in the colon and serum. Furthermore, zy-B markedly altered the gut microbiota composition by enriching Bifidobacterium, Akkermansia, and Lactobacillus in the colon. Overall, zy-B appears to act as a probiotic to alleviate Vp infection by protecting the intestinal barrier, reducing inflammation, and promoting the growth of "beneficial" gut microbiota.

Multidetector Computed Tomography and MR Imaging Findings in Mycotic Infections

Fungal infections constitute a diverse spectrum of infections with variable clinical and imaging features. They are commonly opportunistic infections that affect immunocompromised individuals secondary to inherited or acquired disorders. Fungal infections may affect multiple organ systems and contribute to significant morbidity and mortality. Although the imaging features of some fungal infections are characteristic and permit their diagnosis, many mycotic infections manifest nonspecific findings. Definitive diagnosis often depends on histopathological analysis. Early diagnosis requires both clinical suspicion and supporting radiological evidence. Early treatment results in reduced morbidity and mortality. This article reviews the imaging findings in opportunistic and endemic fungal infections.

Transient angioedema of small bowel secondary to intravenous iodinated contrast medium

We report the clinical details and imaging findings of a case of transient angioedema of the small bowel following intravenous administration of non-ionic iodinated contrast material in a 17 year old female with no predisposing risk factors. Findings included long segment, symmetric, circumferential, low-density, bowel wall thickening involving the duodenum, jejunum, and most of the ileum on computed tomography scan obtained at 7 min following intravenous contrast material injection. This entity is self-limiting with a favourable clinical outcome and requires no specific treatment but only aggressive clinical monitoring.