Absence of toll-like receptor 7 ameliorates survival and reduces intestinal injury in mice after Clostridium difficile infection

Clostridioides difficile (CD) is a major cause of antibiotic-associated diarrhea and pseudomembranous enteritis. C. difficile infection (CDI) is increasingly present in the community and represents a significant burden on the healthcare system. Identification of novel immune-based therapeutic targets from a better understanding of their molecular pathogenesis is urgently required. Toll-like receptor 7 (TLR7) is an important pattern recognition receptor and function as an immune sensor that can trigger host defenses against pathogens, but the relationship between TLR7 and CDI remains unknown. Here, we reported that the expression levels of TLR7 increased significantly in patients and mice with CDI. Absence of TLR7 in mice with CDI demonstrated enhanced bacterial clearance of intestinal contents and reduced intestinal inflammation, edema, injury and prolonged the survival. TLR7 loss decreased the concentrations of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and IFN-α1 in the intestine and improved tissue damage and inflammation. Flow cytometry and immunofluorescence results indicated that TLR7 enhanced leukocyte recruitment in the infected intestine. In-vitro results have shown that TLR7 impairs the phagocytosis and killing ability of macrophages to CD, prompts reactive oxygen species (ROS) production and accelerates apoptosis. To our knowledge, our study first identified TLR7 as a critical factor that contributes to the immunopathology of CDI, suggesting that targeting TLR7 might serve as a potential treatment for CDI.

Salmonella Reading: A rare case of generalized salmonellosis in non-endemic region

Salmonella Reading is a rare serotype of Salmonella enterica and is associated with sporadic cases and rare outbreaks worldwide. This article describes a rare case of generalized S. Reading infection imported from Indonesia to Moscow, Russia. A 37-year-old man was admitted to the hospital with fever, weakness, and headache after returning from Indonesia. During his stay in Indonesia, he developed symptoms of a gastrointestinal infection, which resolved there. However, upon return to Moscow, his condition worsened due to high fever, and he was diagnosed with a generalized salmonellosis caused by S. Reading (positive blood and stool culture). This case highlights the importance of differential diagnosis in patients with fever. The health risks associated with traveling to exotic countries and the importance of preventive measures are emphasized. This is the first published case of S. Reading in Eastern Europe.

Colon Cancer Risk Following Intestinal Clostridioides difficile Infection: A Longitudinal Cohort Study

Background

The gut microbiome may play an important role in the etiology and progression of colon cancer. The present hypothesis-testing study compared the colon cancer incidence rate among adults diagnosed with intestinal Clostridioides (formerly Clostridium) difficile (Cdiff) (the Cdiff cohort) to adults not diagnosed with intestinal Cdiff infection (the non-Cdiff cohort).

Methods

De-identified eligibility and claim healthcare records within the Independent Healthcare Research Database (IHRD) from a longitudinal cohort of adults (the overall cohort) enrolled in the Florida Medicaid system between 1990 through 2012 were examined. Adults with ≥ 8 outpatient office visits over 8 years of continuous eligibility were examined. There were 964 adults in the Cdiff cohort and 292,136 adults in the non-Cdiff cohort. Frequency and Cox proportional hazards models were utilized.

Results

Colon cancer incidence rate in the non-Cdiff cohort remained relatively uniform over the entire study period, whereas a marked increase was observed in the Cdiff cohort within the first 4 years of a Cdiff diagnosis. Colon cancer incidence was significantly increased (about 2.7-fold) in the Cdiff cohort (3.11 per 1,000 person-years) compared to the non-Cdiff cohort (1.16 per 1,000 person-years). Adjustments for gender, age, residency, birthdate, colonoscopy screening, family history of cancer, and personal history of tobacco abuse, alcohol abuse/dependence, drug abuse/dependence, and overweight/obesity, as well as consideration of diagnostic status for ulcerative and infection colitis, immunodeficiency, and personal history of cancer did not significantly change the observed results.

Conclusions

This is the first epidemiological study associating Cdiff with an increased risk for colon cancer. Future studies should further evaluate this relationship.

Genomic and phenotypic profiling of Staphylococcus aureus isolates from bovine mastitis for antibiotic resistance and intestinal infectivity

BACKGROUND

Staphylococcus aureus is one of the prevalent etiological agents of contagious bovine mastitis, causing a significant economic burden on the global dairy industry. Given the emergence of antibiotic resistance (ABR) and possible zoonotic spillovers, S aureus from mastitic cattle pose threat to both veterinary and public health. Therefore, assessment of their ABR status and pathogenic translation in human infection models is crucial.

RESULTS

In this study, 43 S. aureus isolates associated with bovine mastitis obtained from four different Canadian provinces (Alberta, Ontario, Quebec, and Atlantic provinces) were tested for ABR and virulence through phenotypic and genotypic profiling. All 43 isolates exhibited crucial virulence characteristics such as hemolysis, and biofilm formation, and six isolates from ST151, ST352, and ST8 categories showed ABR. Genes associated with ABR (tetK, tetM, aac6', norA, norB, lmrS, blaR, blaZ, etc.), toxin production (hla, hlab, lukD, etc.), adherence (fmbA, fnbB, clfA, clfB, icaABCD, etc.), and host immune invasion (spa, sbi, cap, adsA, etc.) were identified by analyzing whole-genome sequences. Although none of the isolates possessed human adaptation genes, both groups of ABR and antibiotic-susceptible isolates demonstrated intracellular invasion, colonization, infection, and death of human intestinal epithelial cells (Caco-2), and Caenorhabditis elegans. Notably, the susceptibilities of S. aureus towards antibiotics such as streptomycin, kanamycin, and ampicillin were altered when the bacteria were internalized in Caco-2 cells and C. elegans. Meanwhile, tetracycline, chloramphenicol, and ceftiofur were comparatively more effective with ≤ 2.5 log₁₀ reductions of intracellular S. aureus.

CONCLUSIONS

This study demonstrated the potential of S. aureus isolated from mastitis cows to possess virulence characteristics enabling invasion of intestinal cells thus calling for developing therapeutics capable of targeting drug-resistant intracellular pathogens for effective disease management.

Virological and histological evaluation of intestinal samples in COVID-19 patients

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen responsible for pandemic coronavirus disease 2019 (COVID-19). It is a highly contagious virus which primarily affects the respiratory tract, nevertheless, the lungs are not the only target organs of the virus. The intestinal tract could represent an additional tropism site for SARS-CoV-2. Several observations have collectively suggested that enteric infections can occur in COVID-19 patients. However, the detection of viral RNA in gastrointestinal (GI) tissue samples has not been adequately investigated and results are conflicting.

AIM

To detect the presence of SARS-CoV-2 RNA in intestinal mucosa samples and to evaluate histological features.

METHODS

The COVID-19 patients hospitalized at an Italian tertiary hospital from April 2020 to March 2021 were evaluated for enrollment in an observational, monocentric trial. The study population was composed of two groups of adult patients. In the first group (biopsy group, 30 patients), patients were eligible for inclusion if they had mild to moderate disease and if they agreed to have a rectal biopsy; in the second group (surgical specimen group, 6 patients), patients were eligible for inclusion if they underwent intestinal resection during index hospitalization. Fifty-nine intestinal mucosal samples were analyzed.

RESULTS

Viral RNA was not detectable in any of the rectal biopsies performed (0/53). Histological examination showed no enterocyte damage, but slight edema of the lamina propria with mild inflammatory lymphoplasmacytic infiltration. There was no difference in inflammatory infiltrates in patients with and without GI symptoms. SARS-CoV-2 RNA was detected in fecal samples in 6 cases out of 14 cases examined (42.9%). In the surgical specimen group, all patients underwent emergency intestinal resection. Viral RNA was detected in 2 surgical specimens of the 6 examined, both of which were from patients with active neoplastic disease. Histological examination also pointed out abundant macrophages, granulocytes and plasma cells infiltrating the muscular layer and adipose tissue, and focal vasculitis.

CONCLUSION

Mild-moderate COVID-19 may not be associated with rectal infection by the virus. More comprehensive autopsies or surgical specimens are needed to provide histological evidence of intestinal infection.

Protective effects elicited by cow milk fermented with L. Paracasei CBAL74 against SARS-CoV-2 infection in human enterocytes

Fermented foods have been proposed in limiting SARS-CoV-2 infection. Emerging evidence suggest the efficacy of cow's milk fermented with the probiotic L. paracasei CBAL74 (FM-CBAL74) in preventing infectious diseases. We evaluated the protective action of FM-CBAL74 against SARS-CoV-2 infection in human enterocytes. Relevant aspects of SARS-CoV-2 infection were assessed: infectivity, host functional receptor angiotensin-converting enzyme-2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and pro-inflammatory cytokines expression (IL-6, IL-15, IL-1β, VEGFβ, TNF-α, MCP-1, CXCL1). Pre-incubation with FM-CBA L74 reduced the number of infected cells. The expression of ACE2 and the pro-inflammatory cytokines IL-6, VEGFβ, IL-15, IL-1β was downregulated by the pre-treatment with this fermented food. No effect on TMPRSS2, MCP-1, TNF-α and CXCL1 expression was observed. Modulating the crucial aspects of the infection, the fermented food FM-CBAL74 exerts a preventive action against SARS-CoV-2. These evidence could pave the way to innovative nutritional strategy to mitigate the COVID-19.

Assessment of probiotic adhesion and inhibitory effect on Escherichia coli and Salmonella adhesion

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73-55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application.

A 21-year retrospective analysis of environmental impacts on paediatric acute gastroenteritis in an affluent setting

BACKGROUND

Extreme weather events happen more frequently along with global warming and they constitute a challenge for public health preparedness. For example, many investigations showed heavy rainfall was associated with an increased risk of acute gastroenteritis. In this study, we examined the associations between different meteorological factors and paediatric acute gastroenteritis in an affluent setting in China controlling for pollutant effects.

METHODS

Aggregated total weekly number of intestinal infection-related hospital admissions, and meteorological and air pollution data during 1998-2018 in Hong Kong were collected and analysed by a combination of quasi-Poisson generalized additive model and distributed lag nonlinear model. Study population was restricted to children under 5 years of age at the time of admission.

RESULTS

While heavy rainfall did not exhibit a statistically significant association with the risk of paediatric admission due to intestinal infections, low temperature and humidity extremes (both relative humidity and vapour pressure) did. Compared with the temperature at which the lowest risk was detected (i.e. 22.5 °C), the risk was 6.4% higher (95% confidence interval: 0.0% to 13.0% at 15.1 °C (i.e. the 5th percentile)). We also found the risk of paediatric admission was statistically significantly associated with an increase in the number of extreme cold days in a week over the study period.

CONCLUSION

Cold condition may have greater impact on disease transmission through increased stability and infectivity of enteric viruses in affluent settings like Hong Kong and thus resulted in an increased risk for paediatric acute gastroenteritis. On the contrary, an insignificant impact from heavy rainfall and high temperature may indicate a minor effect on disease transmission through bacterial growth in contaminated food and water. With the identified impacts of weather factors, extreme weather events are likely to distort the prevalence and seasonal pattern of diarrhoeal diseases in the future.

Elective Caesarean Delivery Associated with Infant Hospitalisation for Intestinal But Not Respiratory Infection

OBJECTIVES

We assessed the impact of caesarean delivery on offspring respiratory and intestinal infection.

METHODS

Data were extracted from all live births (n = 429,058) occurring in the Australian state of Queensland between January 2009 and December 2015, and followed for 12 months. Births were categorised as either non-medically indicated caesarean or vaginal delivery and each offspring had a record (present/absent) of respiratory and intestinal infection hospitalisation for each month from birth to 12 months.

RESULTS

Infants delivered by non-medically indicated caesarean were more likely to experience respiratory infection [OR = 1.51 (1.15, 1.99)] and intestinal infection [OR = 1.74 (1.19, 2.55)] than those born by vaginal delivery. In the propensity score weighted analyses the estimate for respiratory infection was similar but non-significant [OR = 1.52 (0.99, 2.31)], while the association with intestinal infection strengthened [OR = 2.21 (1.25, 3.89)].

CONCLUSIONS FOR PRATICE

Our findings provide strong evidence for a specific and clinically meaningful link between non-medically indicated caesarean delivery and infant intestinal infection.

Potential clinical use of azithromycin against gastroenteritis-causing pathogens other than Campylobacter

The activity of azithromycin against enteritis-producing agents other than Campylobacter spp. was studied. The susceptibility to azithromycin, through gradient test, of 88 clinical isolates (51 Salmonella spp., 23 Aeromonas spp., 10 Shigella sonnei and 4 Yersinia enterocolitica) for one year was studied prospectively. The results were compared with the activity of ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin by microdilution. For azithromycin, the minimum inhibitory concentration (MIC) 50 and MIC90 were 4 and 12 mg/l, respectively. Six (6.8%) isolates were simultaneously resistant to ampicillin, trimethoprim- sulfamethoxazole and ciprofloxacin, and 3 (50%) of them presented a MIC >256 mg/l. Azithromycin may be a good empirical therapeutic option for the treatment of bacterial enteritis.

Daily consumption of a homeopathic product decreases intestinal damage and stool bacterial counts in mice challenged with Escherichia coli

Escherichia coli is a bacterium normally found in the gastrointestinal tract of domestic animals that can usually control the infection. Nevertheless, some factors (high exposure, stress conditions, animal category, among others) can favor the exacerbation of E. coli infection and cause of disease. Because it is a zoonotic bacterium, it is important to control the infection, avoiding contamination of home interiors in the case of pets. There are various forms of treatment for E. coli; nevertheless, there are few options for prevention. In the present study, we evaluated homeopathy. Thus, the objective of this study was to determine whether administration of a prophylactic homeopathic in water would minimize the negative effects of E. coli infection, as well as reducing bacterial counts in the feces of a experimental model. Forty mice were divided into four experimental groups (n = 10/group). Groups NC (negative control) and PC (positive control) were not treated; in group T1, the animals received 0.002 mL/day/animal of the homeopathic in water, and animals in group T2 0.004 mL/day/animal. The experiment lasted 54 days, and on the 31st day, mice of T1, T2 and PC groups were infected orally a 0.2 mL inoculum of 1.5 × 10⁸ CFU of E. coli. Euthanasia and sample collection were performed on the 40th and 54th days of the experiment (n = 5/group/time point). Blood, liver, spleen, intestine, and feces samples were collected from the final portion of the intestine. There was no significant difference in animal weight between groups at the end of the experiment. Neutrophil count was lower in PC group animals on day 40, while on day 54, the counts were lower in T2 and PC. Lymphocyte counts were lower only in the PC group than in the NC group on day 54. Globulins were lower in the NC and PC groups than in T1 and T2 on day 40, remaining lower the PC group and higher in T1 on day 54; levels of immunoglobulin IgG and IgM were higher in groups T1 and T2, which differed from PC and NC. TNF-α levels were higher in the T1 and T2 groups at 40 and 54 days. INF-γ levels were higher in T1, T2, and PC compared to NC on day 40, remaining higher than NC in groups T1 and T2 on day 54. Total bacterial count, total coliforms and E. coli counts were lower in group T1 and higher in NC and PC on days 40 and 54, when they were lower for T1 and T2. Histologically, no lesions were observed in extra-intestinal tissues; however the height of intestinal crypts in the PC group was smaller than the others on day 40. On day 54, villi and crypts of all infected groups were larger in T1 and T2 than in NC; sizes in the PC group were higher than those of all other groups. These data suggest that the homeopathic agent in the drinking water improved health of the mice.

Quantification of Bacteria Residing in Caenorhabditis elegans Intestine

Quantification of intestinal colonization by pathogenic or commensal bacteria constitute a critical part of the analysis to understand host-microbe interactions during different time points of their interplay. Here we detail a method to isolate non-pathogenic and pathogenic bacteria from C. elegans intestines, and classify gut phenotypes induced by bacterial pathogens using fluorescently-tagged bacteria. Furthermore, these methods can be used to isolate and identify new culturable bacterial species from natural microbiomes of wild nematodes.

Persistence of intestinal SARS-CoV-2 infection in patients with COVID-19 leads to re-admission after pneumonia resolved

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Intestine SARS-CoV-2 infection affects the disease course of COVID-19.

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The digestive system is the main target organ of SARS-CoV-2 in some patients.

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Viral excretion of SARS-CoV-2 in feces.

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Management of patients with COVID-19 after discharge should include intestine SARS-CoV-2 infection.

The current reports of COVID-19 focus on the respiratory system, however, intestinal infections caused by SARS-CoV-2 are also worthy of attention. This paper reported persistence of intestinal SARS-CoV-2 infection leads to re-admission after pneumonia resolved in three cases with COVID-19.

Evaluating single-domain antibodies as carriers for targeted vaccine delivery to the small intestinal epithelium

Targeting a vaccine to the mucosal surface has recently been recognized as a promising approach to efficiently induce mucosal immune responses against enteric pathogens. However, poor uptake and inefficient transport of orally delivered subunit vaccines across the intestinal epithelium combined with weak immune responses still present important bottlenecks for mucosal vaccination. A possible strategy suggested to surmount these hurdles is to target the selected antigen to transcytotic receptors, such as aminopeptidase N (APN) present on enterocytes and antigen-presenting cells (APCs). Therefore, we aimed to identify potent and selective VHHs against porcine aminopeptidase N (pAPN), that were fused to the fragment crystallizable (Fc) domain of the murine IgG2a, resulting in dimeric VHH-MG fusions. Out of a library of 30 VHH-MG fusion candidates, two fusions displaying the best binding on pAPN-expressing cells were selected and showed in vivo internalization across the porcine gut epithelium. One of these fusions triggered systemic and intestinal IgA responses upon oral administration. Our results demonstrate the potential of bivalent VHH-MG fusions as delivery vehicles for vaccine antigens. VHH-mediated targeting of antigens to APN to generate protective immunity at the mucosal surface remains to be further validated.

The first molecular detection of Blastocystis subtypes in human faecal samples from Ibague, Colombia

Blastocystis spp. has become one of the protozoans arousing the greatest scientific interest because of the controversy surrounding its biology; it is currently considered one of the most prevalent organisms in humans and animals worldwide. Such prevalence increases, especially in tropical countries where infection rates are high, highlighting the need to conduct studies focused on understanding this protozoan's biology. Interestingly, molecular tools are emerging as the best option for diagnosing this infection. This study was thus aimed at conventional PCR molecular detection and characterisation of Blastocystis spp. in human faecal samples from Ibagué, Colombia, using primers targeting the small subunit ribosomal ribonucleic acid (rRNA) gene. One hundred human faecal samples with confirmed Blastocystis spp. were studied, revealing the following subtype genetic diversity: ST1 50%, ST2 33% and ST3 17%. The results contributed to the limited information available regarding Blastocystis spp. in Colombia and created a reference point for further studies in the region.

Anthelmintic Potential of Cucurbita pepo Seeds on Hymenolepis nana

OBJECTIVE

The main drug used against Hymenolepis nana is praziquantel (PZQ), which causes side effects and toxicity. In contrast, natural extracts have limited side effects and are safer. Past researches have proved that pumpkin seeds are effective as natural antimicrobial and antiparasitic treatment. The present study investigates a natural alternative and less expensive treatment against H. nana using pumpkin seeds.

MATERIALS AND METHODS

Healthy female albino mice were divided into four groups: normal control, infected control with H. nana, infected and treated with PZQ, and lastly, the group infected and treated with pumpkin seeds' extract.

RESULTS

Pumpkin seeds aqueous extract showed a significant reduction (P < 0.05) in the number and length of H. nana adult worms, number and viability of eggs in comparison to the infected control group and PZQ group. Pumpkin seed aqueous extract is proven to be an effective anthelmintic against H. nana.

CONCLUSION

We recommend pumpkin seed extract as a natural alternative, less expensive and safe therapy for H. nana. This is the first study in Saudi Arabia to investigate the therapeutic effect of pumpkin seeds' extract on H. nana.

Diversity of Saccharomyces boulardii CNCM I-745 mechanisms of action against intestinal infections

The yeast Saccharomyces boulardii CNCM I-745 is one of the probiotics recommended for the prevention of antibiotic-associated diarrhea. Studies conducted in vivo and in vitro demonstrated that in the case of infectious diseases there are two potential sites of action of Saccharomyces boulardii CNCM I-745: (1) An action on enteropathogenic microorganisms (adhesion of bacteria and their elimination or an effect on their virulence factors: Toxins, lipopolysaccharide, etc.); and (2) a direct action on the intestinal mucosa (trophic effects, effects on epithelial reconstitution, anti-secretory effects, anti-inflammatory, immunomodulators). Oral administration of Saccharomyces boulardii CNCM I-745 to healthy subjects does not alter their microbiota. However, in the case of diseases associated with the use of antibiotics or chronic diarrhea, Saccharomyces boulardii CNCM I-745 can restore the intestinal microbiota faster. The interaction of Saccharomyces boulardii CNCM I-745 with the innate immune system have been recently demonstrated thus opening up a new therapeutic potential of this yeast in the case of diseases associated with intestinal infections but also other pathologies associated with dysbiosis such as inflammatory diseases.

The combination of fecal calprotectin with ESR, CRP and albumin discriminates more accurately children with Crohn's disease

PURPOSE

Increased fecal calprotectin is a sensitive marker of various types of intestinal inflammation. We investigated correlations between high fecal calprotectin concentration and serum inflammatory markers in children with different intestinal diseases with diarrhea with/without blood and/or abdominal pain, to test whether the combination of these markers can differentiate potential patients with inflammatory bowel disease.

MATERIALS/METHODS

The study included 128 children with high fecal calprotectin concentration (>150ug/g) and symptoms suggesting bowel disorders, hospitalized in the years 2013- 2015. Twenty-six (20%) patients were diagnosed with Crohn's disease, 55 (43%) with ulcerative colitis, 32 (25%) with intestinal infection and 15 (12%) with food protein induced proctocolitis.

RESULTS

Significantly increased inflammatory markers were detected in children with inflammatory bowel disease, with a correlation between calprotectin and erythrocyte sedimentation rate - ESR (R = 0.53), mean corpuscular volume - MCV (R=-0.64), red blood cell distribution width (R = 0.56), albumin (R = -0.52), hemoglobin (R = -0.53) only in Crohn's disease patients. To discriminate Crohn's disease patients from patients with intestinal infection and patients with food protein induced proctocolitis, AUC analysis was performed. It revealed that considering ESR, CRP and albumin as additional markers to fecal calprotectin significantly improved diagnostic performance (AUC 0.917, p = 0.038).

CONCLUSIONS

In children with abdominal pain and/or diarrhea, increased ESR, CRP and decreased albumin combined with a high fecal calprotectin level yields additional diagnostic value in screening potential patients with Crohn's disease. As far as differentiation of ulcerative colitis is concerned, low additional diagnostic value was found when high fecal calprotectin was combined with albumin.

[Primary intestinal actinomycosis in ilium and colon. A case report and review of the literature]

Actinomycosis is a chronic, suppurative, inflammatory granulomatous disease caused by gram positive anaerobic filamentous bacteria of the genus Actinomyces, most frequently Actinomyces israelii. We report a case of a 42-year-old male presenting with abdominal pain, a 10kg weight loss and a fixed mass in the epigastrium. Tomography revealed dilatation of the intestinal loops and thickening of the colon walls; the coexistence of these two findings suggested a lymphoproliferative process. The tumour, ileum fragment and colon were surgically removed; these were adherent to the serosal fibro-adipose tissue. Microscopically, abundant polymorphonuclear infiltrate and grains of bacteria compatible with Actinomyces spp.were seen.

Effect of Lactobacillus rhamnosus GG supernatant on serotonin transporter expression in rats with post-infectious irritable bowel syndrome

AIM

To evaluate the effect of Lactobacillus rhamnosus GG supernatant (LGG-s) on the expression of serotonin transporter (SERT) in rats with post-infectious irritable bowel syndrome (PI-IBS).

METHODS

Campylobacter jejuni 81-176 (10¹⁰ CFU/mL) was used to induce intestinal infection to develop a PI-IBS model. After evaluation of the post-infectious phase by biochemical tests, DNA agarose gel electrophoresis, abdominal withdrawal reflex (AWR) test, and the intestinal motility test, four PI-IBS groups received different concentrations of LGG-s for 4 wk. The treatments were maintained for 1.0, 2.0, 3.0 or 4.0 wk during the experiment, and the colons and brains were removed for later use each week. SERT mRNA and protein levels were detected by real-time PCR and Western blot, respectively.

RESULTS

The levels of SERT mRNA and protein in intestinal tissue were higher in rats treated with LGG-s than in control rats and PI-IBS rats gavaged with PBS during the whole study. Undiluted LGG-s up-regulated SERT mRNA level by 2.67 times compared with the control group by week 2, and SERT mRNA expression kept increasing later. Double-diluted LGG-s was similar to undiluted-LGG-s, resulting in high levels of SERT mRNA. Triple-diluted LGG-s up-regulated SERT mRNA expression level by 6.9-times compared with the control group, but SERT mRNA expression decreased rapidly at the end of the second week. At the first week, SERT protein levels were basically comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triple-diluted LGG-s, which were higher than those in the control group and PBS-treated PI-IBS group. SERT protein levels in the intestine were also comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triple-diluted LGG-s by the second and third weeks. SERT mRNA and protein levels in the brain had no statistical difference in the groups during the experiment.

CONCLUSION

LGG-s can up-regulate SERT mRNA and protein levels in intestinal tissue but has no influence in brain tissue in rats with PI-IBS.

Celiac Disease: What Do We Know in 2017?

Celiac disease is one of the most prevalent digestive conditions. Diagnosis requires that strict criteria are used so that a life-long gluten-free diet may be correctly prescribed. Although genetic susceptibility has been known for a long time, there have been elusive environmental factors that lead to the occurrence of clinical disease. Many studies have addressed the identification of environmental modifiers, and different lines of research have been tried with variable success and even contradictory results. Infections and age of gluten introduction into the diet in the first few months of life have been evaluated, but a firm relationship could not be established. A recent paper addresses a fascinating hypothesis that could explain how some infectious agents might modulate the immune system and modify response to dietary antigens. Subsequently, animal models with genetic susceptibility were tested, and, indeed, there was abnormal response to gluten. These observations still do not provide final answers about the pathophysiology of celiac disease but certainly lead to progress in the knowledge of gluten sensitization and the role of some environmental factors.

Intestinal Bacterial Infection Diagnosed by Histological Examination of Endoscopic Biopsy Specimens

Intestinal spirochetosis (IS) in humans is characterized by spirochetal microorganisms attached to the luminal surface of the colonic epithelium. In the present case, attached organisms appeared as 3- to 4 μm-thick (average thickness, 3.4 μm) basophilic fringes or haze in HE-stained endoscopic biopsy specimens. The basophilic fringes were clearly labeled by Treponema pallidum antiserum. Because IS is relatively rare in developed countries, thin basophilic fringes characteristic of IS are readily overlooked. Thus, the recognition of histological characteristics of this disease is important for its diagnosis.

Intestinal infection associated with future onset of an anxiety disorder: Results of a nationally representative study

Recent research involving mice suggests a possible relationship between intestinal infection and future anxiety-like behavior. However, there has been little epidemiological research showing such a connection in humans. This study uses the Medical Expenditure Panel Survey (MEPS) to assess longitudinally the association between intestinal infection and later onset of an anxiety disorder, through a nationally representative sample. Six 2-year panel datasets, each comprised of 5 consecutive rounds, were pooled from 2007 to 2013 to gather records for all respondents 18years of age or older that did not have an anxiety disorder in Round 1 (n=63, 133 people). Within the study sample, there were 2577 individuals with an intestinal infection in Round 1 and 4239 individuals with an anxiety disorder that began in Round 2, 3, 4, or 5. Overall, intestinal infection in Round 1 was associated with a 1.34 (P<0.01) odds ratio of having an anxiety disorder that began in Round 2, 3, 4, or 5. Separate analyses were performed to determine whether the association applied to other infection types, including respiratory infection, urinary tract infection, hepatitis infection, and skin infection. Respiratory infection was associated with a 1.36 (P<0.01) odds ratio of having an anxiety disorder that began in Round 2, 3, 4, or 5; no other infection type showed a significant association. More research on human populations is needed to examine the apparent association and explore potential mechanisms by which gut pathogens might influence anxiety.

First case of intestinal acariasis from Egypt

We are hereby reporting a case where the eggs and adults of the mold mites; Tyrophagus putrescentiae (Shrank) and the trophozoites of Blastocystis sp. were found in stool of three years old child from Minia City, Egypt. Intestinal mite infection was diagnosed after repeated identification of mite’ stages from six consecutive stool samples to exclude the possibilities of contamination and spurious infection. The patient was suffering from severe colicky abdominal pain and burning sensation around the anus one month ago. All other members of his family were having the same acarine in their feces, but were all symptomless. The patient was treated with ivermectin 200 µg/kg body weight once every 10 days for three doses. His cure indicated that he was having asymptomatic blastocystosis.

Prevalence of Enterobius vermicularis amongst kindergartens and preschool children in Mazandaran Province, North of Iran

Enterobiasis (oxyuriasis) is probably the most common helminth, which infects humans. Amongst different age groups, prevalence of Enterobius vermicularis in children is high compared to adults. Oxyuriasis is one of the most significant parasitic diseases of children. This nematode in children can result in loss of appetite, insomnia, grinding of the teeth, restlessness, endometritis, abdominal cramps, diarrhea and etc. Due to important complications of this parasite, the objective of the current study was to determine the prevalence of enterobiasis in kindergarten and preschool children of Amol, Mazandaran Province, North of Iran. A total number of 462 children from 32 kindergartens of Amol were examined for the prevalence of E. vermicularis infection, 2013. Adhesive cello-tape anal swab method was trained to parents for sampling. In addition, a questionnaire was designed and filled out to collect demographic information for each individual. Data were analyzed using Chi square test and multivariate logistic regression for each risk factor. The overall prevalence of E. vermicularis infection was 7.1 % (33). Although infection with E. vermicularis in girls 7.9 % was higher compared to boys 6.3 %, there was no significant difference between gender and age (p > 0.05) whereas binary logistic regression showed significant difference between enterobiasis and age (p < 0.05). The findings indicated that the prevalence of E. vermicularis in kindergarten and preschool children is relatively high and still is an important health problem and should not be underestimated due to being highly contagious infection. Therefore, educational programs and mass treatment should be carried out in order to reduce infection incidence in this area and regular parasitological test and attention to personal hygiene in kindergarten and preschool is of great importance.

Role of intestinal infection in pathogenesis of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional digestive disorder characterized by abdominal pain/discomfort and changes in bowel habit (diarrhea and/or constipation). Its etiology and pathogenesis are still not completely clear. In recent years, the relationship between intestinal infection and IBS has attracted increasing attention, since intestinal infection may play a role in the pathogenesis of IBS. This article will review the role of intestinal infection in the pathogenesis of IBS.

Gastrointestinal infection with Mexican TcI Trypanosoma cruzi strains: different degrees of colonization and diverse immune responses

Mexican Ninoa and Queretaro (Qro) TcI strains of Trypanosoma cruzi have shown different degrees of virulence, and the two strains produce heterogeneous immune responses in the hearts of infected mice. This work shows that the same strains can invade the intestine by an intraperitoneal route and establish an infection, mainly in the colon. The three segments of the small intestine (duodenum, jejunum and ileum) were infected to a lesser degree than the colon. Despite the fact that parasites were predominantly found in the colon, an obvious inflammatory reaction was observed in the submucosal layer along the entire intestinal tract, with the virulent Qro strain causing significantly more areas of higher immune infiltration. A clear recruitment of CD4⁺ and CD8⁺ T lymphocytes to the mesenteric ganglia was observed during infection with the virulent strain. Macrophages were also differentially distributed in the gastrointestinal tract. These later cells infiltrated fewer amastigote nests in the mice infected with the Qro strain than in the mice infected with the Ninoa strain. When IFN-γ, TNF-α, and IL-4 levels were measured, an increase in these cytokines was observed compared with the uninfected mice. The role of these inflammatory reactions in the pathogenesis of Chagas enteropathy is also discussed in this paper.

Novel perspectives in probiotic treatment: the efficacy and unveiled mechanisms of the physiological functions

Probiotics are defined as "live microorganisms which confer a health benefit on the host" when administered in adequate amounts, and have potential effects for maintaining intestinal development, nutrition, and treating intestinal inflammations, functional disorders, and other extra-intestinal diseases. Although the benefits of probiotics for human health were first noted over 100 years ago, the analysis of probiotic functions began in earnest only 20 years ago. Probiotics, such as some strains of Lactobacillus, Bifidobacterium, Escherichia coli, and Bacillus subtilis, inhibit the growth of pathogenic bacteria, induce competitive effects for the adherent of pathogenic bacteria and their toxins to intestinal epithelia, induce cytoprotective heat shock proteins, enhance the intestinal barrier function, and modulate the host immune responses. The crosstalk between the host and the probiotics appears to be mediated by bacteria-derived effectors, which can be sensed with multiple systems, including the Toll-like receptors and cell membrane transporters. Future analyses will identify more probiotic-derived effectors, the recognition mechanisms of these effectors, and the subsequent changes of the intestinal epithelia and immune cells for each probiotic treatment. For clinical use, a procedure that objectively evaluates the ability of each probiotic effect will help establish a standard for choosing the most valuable strain and its proper dose for each individual patient.