Systematic Review and Meta-Analyses Assessment of the Clinical Efficacy of Bismuth Subsalicylate for Prevention and Treatment of Infectious Diarrhea

Risk Factors of Developing Postinfectious Irritable Bowel Syndrome in Shigellosis Patients, 5 Years After Hospitalization During the Outbreak

Background

Irritable bowel syndrome (IBS) can be triggered by bacterial dysentery. This study aimed to investigate postinfectious IBS and its risk factors after the shigellosis outbreak in hospitalized patients.

Methods

This retrospective study was conducted in 2020-2021 in referral hospitals for Shigella gastroenteritis during the 2014 shigellosis outbreak in Isfahan. The Shigella-infected group included hospitalized shigellosis patients with clinical symptoms and positive stool culture. The control group included patients matched pairwise on age and sex to the Shigella-infected group, admitted to the same hospitals in the same period with diagnoses other than shigellosis. Both groups had no history of diagnosed IBS before the outbreak. The incidence of IBS (according to Rome-III criteria) and its related factors was compared between the 2 groups 5 years after infection.

Results

Of 619 participants, 220 (35.5%) were in the Shigella-infected group. The 5-year incidence of IBS was 31.8% and 5.7% in the Shigella-infected and control groups, respectively. Multivariate analysis showed that shigellosis was significantly associated with increased risk of IBS (odds ratio [OR], 17.18 [95% confidence interval {CI}, 9.37-31.48]). Multivariate analysis indicated education level (OR, 4.15 [95% CI, 1.47-11.73]), diarrhea lasting >4 days (OR, 1.69 [95% CI, 1.17-2.44]), and abdominal cramps during the infection (OR, 0.27 [95% CI, .77-.95]) associated with postinfectious IBS (P < .05).

Conclusions

Hospitalized patients with Shigella gastroenteritis are at increased risk of IBS within 5 years after infection. Factors such as higher education level and the absence of abdominal cramps and diarrhea persisting for >5 days during hospitalization can further increase this risk.

Bioactive Bismuth Compounds: Is Their Toxicity a Barrier to Therapeutic Use?

Bismuth compounds are considered relatively non-toxic, with their low solubility in aqueous solutions (e.g., biological fluids) being the major contributing factor to this property. Bismuth derivatives are widely used for the treatment of peptic ulcers, functional dyspepsia, and chronic gastritis. Moreover, the properties of bismuth compounds have also been extensively explored in two main fields of action: antimicrobial and anticancer. Despite the clinical interest of bismuth-based drugs, several side effects have also been reported. In fact, excessive acute ingestion of bismuth, or abuse for an extended period of time, can lead to toxicity. However, evidence has demonstrated that the discontinuation of these compounds usually reverses their toxic effects. Notwithstanding, the continuously growing use of bismuth products suggests that it is indeed part of our environment and our daily lives, which urges a more in-depth review and investigation into its possible undesired activities. Therefore, this review aims to update the pharmaco-toxicological properties of bismuth compounds. A special focus will be given to in vitro, in vivo, and clinical studies exploring their toxicity.

Collagen and actin network mediate antiviral immunity against Orsay virus in C. elegans intestinal cells

C. elegans is a free-living nematode that is widely used as a small animal model for studying fundamental biological processes and disease mechanisms. Since the discovery of the Orsay virus in 2011, C. elegans also holds the promise of dissecting virus-host interaction networks and innate antiviral immunity pathways in an intact animal. Orsay virus primarily targets the worm intestine, causing enlarged intestinal lumen as well as visible changes to infected cells such as liquefaction of cytoplasm and convoluted apical border. Previous studies of Orsay virus identified that C. elegans is able to mount antiviral responses by DRH-1/RIG-I mediated RNA interference and Intracellular Pathogen Response, a uridylyltransferase that destabilizes viral RNAs by 3' end uridylation, and ubiquitin protein modifications and turnover. To comprehensively search for novel antiviral pathways in C. elegans, we performed genome-wide RNAi screens by bacterial feeding using existing bacterial RNAi libraries covering 94% of the entire genome. Out of the 106 potential antiviral gene hits identified, we investigated those in three new pathways: collagens, actin remodelers, and epigenetic regulators. By characterizing Orsay virus infection in RNAi and mutant worms, our results indicate that collagens likely form a physical barrier in intestine cells to inhibit viral infection by preventing Orsay virus entry. Furthermore, evidence suggests that actin remodeling proteins (unc-34, wve-1 and wsp-1) and chromatin remodelers (nurf-1 and isw-1) exert their antiviral activities by regulating the intestinal actin (act-5), a critical component of the terminal web which likely function as another physical barrier to prevent Orsay infection.

Traveler's diarrhea

ABSTRACT

Traveler's diarrhea (TD) is one of the most common illnesses afflicting the modern traveler. TD refers to a watery diarrhea that varies in severity from tolerable to incapacitating and that develops in individuals during or within 10 days of returning from travel to developing or low-/middle-income countries. Most cases of TD are self-limiting, but in consideration of the ease of international travel, it is important for providers to diagnose and manage TD with the best available evidence.

Biological Activities of Bismuth Compounds: An Overview of the New Findings and the Old Challenges Not Yet Overcome

Bismuth-based drugs have been used primarily to treat ulcers caused by Helicobacter pylori and other gastrointestinal ailments. Combined with antibiotics, these drugs also possess synergistic activity, making them ideal for multiple therapy regimens and overcoming bacterial resistance. Compounds based on bismuth have a low cost, are safe for human use, and some of them are also effective against tumoral cells, leishmaniasis, fungi, and viruses. However, these compounds have limited bioavailability in physiological environments. As a result, there is a growing interest in developing new bismuth compounds and approaches to overcome this challenge. Considering the beneficial properties of bismuth and the importance of discovering new drugs, this review focused on the last decade's updates involving bismuth compounds, especially those with potent activity and low toxicity, desirable characteristics for developing new drugs. In addition, bismuth-based compounds with dual activity were also highlighted, as well as their modes of action and structure-activity relationship, among other relevant discoveries. In this way, we hope this review provides a fertile ground for rationalizing new bismuth-based drugs.

Diarrhea as a Clinical Challenge: General Practitioner Approach

BACKGROUND

Diarrhea is defined as the passage of loose stools and increase in stool frequency, weight, or volume. Diarrhea is an important health issue since it accounts for 2.5 million deaths in the world each year.

SUMMARY

Diarrhea can be acute, persistent, or chronic. Acute diarrhea (AD) is usually infectious, caused by viruses, less frequently by bacteria and parasites. The majority of cases of AD are self-limiting and do not require diagnostic workup. The use of diagnostic tests in AD should be limited to patients with signs of severe dehydration, bloody stools, persistent fever and those suffering from immunodeficiencies using immunosuppressive therapy or to cases of suspected nosocomial infection. These patients should be referred to gastroenterologists or infectious disease specialists. Therapy in AD consists of early oral refeeding, antidiarrheal medications, antibiotics, and probiotics. Chronic diarrhea (CD) has diverse etiology. The majority of patients have self-limiting symptoms or functional gastrointestinal disorders. Patients with blood in stool, weight loss, clinical and laboratory signs of anemia, and palpable mass in the abdomen (red flag symptoms) need urgent gastroenterology referral. Therapy in CD is possible when the underlying cause of symptoms is identified.

KEY MESSAGES

The general practitioner should identify high-risk patients with AD and/or red flag symptoms for urgent gastroenterology referral.