Bacterial Gastrointestinal Infections Research Articles

Cation-π Interaction-Enhanced Self-Healing Injectable Hydrogels for Gastric Perforation Repair.

Surgical operations are the preferred treatment for gastric perforation (GP) but incur postoperative complications such as gastrointestinal adhesions and bacterial infections, leading to inefficient wound healing and serious complications that may even threaten the life of the patient. Developing hydrogel dressings capable of adapting to the gastric environment (acid) and decreasing visceral adhesions and bacterial infections after GP treatment is crucial. In this article, we developed an injectable, self-healing hydrogel using cation-π interactions between protonated amines and aromatic rings under acidic conditions and explored it for GP repair. The hydrogels demonstrate exceptional self-healing capabilities under acidic conditions and can be effectively tailored for the gastric environment. In addition, the hydrogel demonstrated significant efficacy in preventing gastrointestinal adhesion, reducing inflammation, promoting angiogenesis, and effectively facilitating wound healing in a rat GP model. This novel hydrogel demonstrates adaptability to the gastric environment, rendering it highly promising for potential applications in gastric trauma healing.

Rapid Establishment of a Regeneration System for Astragalus membranaceus Mongholicus

Background: Astragalus membranaceus Mongholicus (Astragalus) is one of the most widely used medicinal plants in the world. It is a traditional Chinese medicine plant that has been used to treat various human diseases and conditions, such as inflammation, gastrointestinal bacterial infections and malignant tumors. With the expansion of artificial planting areas, the demand for high-quality Astragalus seedlings is also increasing. The traditional seedling-raising methods of direct seeding and induced callus have problems such as a long growth period, unstable genetic traits, strict sampling and rooting difficulties. Therefore, it is very important to multiply the excellent germplasm by optimizing the tissue culture regeneration system. Methods: In this study, Astragalus field cultivated plants, which are easily available, were used as materials and the method of tissue culture cuttings was used to select the direct inoculation method of stem segments as explant materials to establish a plant regeneration system of Astragalus and the best sampling period, sampling site and optimal medium for regeneration of field cultivated plants were screened. Result: The best sampling period for plant regeneration of Astragalus in the field was about 40 d after the emergence of the 3-year-old Astragalus and the rooting rate of the regenerated plants was 100.00%. The best sampling site is the middle section of the stem and the regeneration system using the middle section of the stem as the explant is better than using the top and bottom of the stem as the explant and the rooting rate of the regenerated plants is 100.00%; the best medium for the regenerated plants is N22: 1/2MS+1 mg/L NAA and T28: 1/2MS+1 mg/L ABT, the rooting rates were 76.67% and 96.67%, respectively. The regenerated plants established with the stems of the field cultivated plants of Astragalus as explants were all able to induce seedlings after 1 week and the regenerated seedlings start to take root after 3 weeks of growth and can be transplanted and propagated after 6 weeks of culture. The regeneration system established in this study by direct cuttings from cultivated Astragalus stems is more rapid and efficient, breaking through the difficulties of limited access to material and long growth period of regenerated seedlings in the traditional regeneration system and providing technical support for the conservation and utilization of wild resources of Astragalus and rapid expansion of new varieties and germplasm conservation.

Detection of Campylobacter jejuni based on CRISPR/Cas12a with novel target yclQ obtained by pan-genome analysis

Campylobacter jejuni (C. jejuni) is one of the most common causes of bacterial gastrointestinal foodborne infections worldwide. Conventional detection methods based on bacterial culture are time-consuming, therefore, rapid detection methods are urgently needed to be developed. The objective of this study was to screen a novel species-specific target and to develop a rapid and accurate method for the detection of C. jejuni in food. Through pan-genome analysis of 298 Campylobacter whole-genome sequence data, a new species-specific target yclQ was screened. The yclQ gene was verified through PCR to be unique to C. jejuni. Subsequently, based on the target yclQ, we developed of a CRISPR/Cas12a-based platform for fluorescence visualization and nucleic acid test strips. The RAA-CRISPR/Cas12a system demonstrates the ability to detect C. jejuni at 1.8 CFU/mL within 50 min. Compared to PCR (1.8 × 101 CFU/mL), the RAA and RAA-CRISPR/Cas12a assay showed higher sensitivity. The detection results of the actual samples were consistent with those of the isolation and culture procedures. In conclusion, the RAA-CRISPR/Cas12a system, based on the target yclQ, demonstrates significant potential for the rapid and accurate detection of C. jejuni in food.

Association of metabolic dysfunction-associated fatty liver disease with gastrointestinal infections: insights from National Inpatient Sample Database

ObjectivesThe study aimed to compare the risk of gastrointestinal infections among patients with and without metabolic dysfunction-associated fatty liver disease (MAFLD).MethodsThis was a population-based, retrospective, observational study using data from...

A decade of Campylobacter and Campylobacter bacteraemias in a district general hospital and the surrounding London and South East region, England

Campylobacter bacteraemia is a rare complication of the most common bacterial gastrointestinal infection but is associated with significant morbidity and mortality. There is limited data describing current trends in surveillance and antimicrobial resistance for the Campylobacter strains involved. At the Epsom and St Helier's University Hospital (ESTH), we noted a marked increase in Campylobacter bacteraemia infections in 2021. We extracted Campylobacter reports using the UK Health Security Agency's (UKHSA) Second Generation Surveillance System (laboratory reporting system) between 1st January 2012 and 31st December 2021. We reviewed patient records of patients with Campylobacter bacteraemia for details including presentation, past medical history, duration of hospital stay, and antibiotic use. Between 2012 and 2021, ESTH reported a total of 34 cases of Campylobacter bacteraemia. In 2021, the estimated incidence was 6.8 cases per 100,000 population and in the surrounding area, the incidence was 0.4 per 100,000 population. The incidence rate of Campylobacter bacteraemia in London and the South East region was significantly lower than ESTH (RR = 0.17, p<0.0001). Campylobacter bacteraemia cases at ESTH reported a high number of co-morbidities (average number of comorbidities = 2.3) and had a duration of stay in hospital of a median of 7 days (IQR = 4-10 days). Campylobacter jejuni was the most commonly reported species for stool and blood Campylobacter in ESTH, London, and South East England. Campylobacter bacteraemia reports at ESTH were significantly (p<0.001) higher than the surrounding London and South East region. While no common cause for the exceedance of Campylobacter bacteraemia has been identified, common risk factors for Campylobacter bacteraemia infection include underlying health conditions, being older, and male.

Synthesis and characterization of chitosan/polyvinylpyrrolidone hydrogels for controlled amoxicillin release

Hybrid crosslinked hydrogel-based drug delivery systems can deliver therapeutically beneficial drug release effects through controlled release on a temporal and spatial scale. Due to their tuneable physicochemical properties and the ability to prevent drug degradation, these systems facilitate different physicochemical interactions that control drug release. This research aims to synthesize a potent pH-sensitive crosslinked chitosan/polyvinylpyrrolidone hydrogel using different ratios of both the polymers and varying the glutaraldehyde crosslinking agent amount by the solution casting technique for controlled amoxicillin-release properties to mitigate gastrointestinal tract bacterial infection. The effect of polymer ratios and glutaraldehyde amount is investigated by the developing porosity, gel fraction, and extent of swelling in simulated physiological fluids of pH 1.2, 6.8, and 7.4 and in vitro biodegradation at pH 7.4. Interaction between the polymers with the formation of crosslinked structures, good stability, amorphous phase nature, and honeycomb-like structures of the hydrogels is revealed by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. Based on these properties, a chitosan/polyvinylpyrrolidone hydrogel (ratio of 60:40) crosslinked with 600 μL glutaraldehyde in 8 g of the polymers displaying adequate swelling in acidic to basic pH and in vitro biodegradation at pH 7.4 is chosen for the in situ loading of 200 mg of the drug amoxicillin. The cumulative drug release in simulated physiological fluids and the drug release kinetics using different models show that the best-fit Korsmeyer-Peppas model suggests amoxicillin release from the matrix follows diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This composition displays excellent antimicrobial activity against Streptococcus pyogenes and Escherichia coli.

Polyamines and hypusination are important for Clostridioides difficile toxin B (TcdB)-mediated activation of group 3 innate lymphocytes (ILC3s).

Clostridioides difficile is the most common cause of nosocomial gastrointestinal tract bacterial infections. We lack fully effective reliable treatments for this pathogen, and there is a critical need to better understand how C. difficile interacts with our immune system. Group 3 innate lymphocytes (ILC3s) are rare immune cells localized within mucosal tissues that protect against bacterial infections. Upon activation, ILC3s secrete high levels of the cytokine interleukin-22 (IL-22), which is a critical regulator of tissue responses during infection. C. difficile toxin B (TcdB), the major virulence factor, directly activates ILC3s, resulting in high IL-22 levels. We previously reported that polyamines are important in the activation of ILC3s by the innate cytokine interleukin-23 (IL-23) but did not identify a specific mechanism. In this study, we examine how a pathogen impacts a metabolic pathway important for immune cell function and hypothesized that polyamines are important in TcdB-mediated ILC3 activation. We show that TcdB upregulates the polyamine biosynthesis pathway, and the inhibition of the pathway decreases TcdB-mediated ILC3 activation. Two polyamines, putrescine and spermidine, are involved. Spermidine is the key polyamine in the hypusination of eukaryotic initiation factor 5A (eIF5A), and the inhibition of eIF5A reduced ILC3 activation. Thus, there is potential to leverage polyamines in ILC3s to promote activation of ILC3s during C. difficile infection and other bacterial infections where ILC3s serve a protective role.

Antibacterial Activity of Ethanol Extract of Purple Kencana Leaves (Ruellia tuberosa L.) Using TLC-Bioautography and Agar Diffusion Methods

Tunjuk Langit Plant (Helminthostachys zeylanica (L.) Hook) contains a lot of secondary metabolite compounds, one of which is found in the root which contain the flavonoids ugonin and quercetin. The purpose of this study was to determine the antibacterial activity of compound 4 isolates IFATL-05 endophytic fungi from Tunjuk Langit (Helminthostachys zeylanica (L.) Hook) root against bacterial gastrointestinal tract infection. The results of purification of endophytic fungi with IFATL-05 code on macroscopic examination showed blackish-white fungus color, round with scalloped colony shapes, wavy edges and drop-like elevation angles. The process of separating the compounds using KLTP with n-hexane:ethyl acetate (1:1) as an eluent resulted in four bands of active compounds in UV lamps of 254 and 366 nm (TL-1, TL-2, TL-3 and TL-4). Test results for compound 4 isolates of IFATL-05 endophytic fungi from Tunjuk Langit root (Helminthostachys zeylanica (L.) Hook) using the Bioautographic TLC method using n-hexane:ethyl acetate (6:1) as eluent on Escherichia coli, Salmonella thypi, Shigella dysenteriae and Vibrio cholerae with Rf value = 0.90.

Fabrication of pH‐sensitive double cross‐linked sodium alginate/chitosan hydrogels for controlled release of amoxicillin

AbstractThis research aims to fabricate a potent pH‐sensitive double network sodium alginate/chitosan hydrogel cross‐linked by calcium chloride (CaCl2) and glutaraldehyde for the controlled release of amoxicillin (AMX) to mitigate gastrointestinal tract bacterial infection. The effect of polymer ratios and CaCl2 concentration is investigated by the developing porosity, gel fraction, and swelling ratios in simulated physiological fluids of different pH and in vitro biodegradation at pH 7.4. Interaction between the polymers with the formation of cross‐linked structures, amorphous phase nature, good thermal stability, and transition from porous, fibrous structures to highly densified structures of the hydrogels is revealed by scanning electron microscopy, Fourier‐transform infrared spectroscopy, x‐ray diffraction, and thermogravimetric analysis. Based on structure–property relationships, a sodium alginate/chitosan hydrogel (weight ratio 75:25) cross‐linked with 2% CaCl2 and soaked in 2% (25 wt/v% solutions) glutaraldehyde is chosen for the incorporation of 200 mg of the drug. The percent cumulative AMX release in physiological fluids and the drug release kinetics using different models reveal that the most appropriate Korsmeyer–Peppas model suggests AMX release from the matrix follows diffusion coupled with swelling‐regulated time‐dependent non‐Fickian transport process related to hydrogel erosion. Excellent antibacterial against Streptococcus pyogenes and Escherichia coli is exhibited by this composition.

The ethanol extract of Scutellaria baicalensis Georgi attenuates complete Freund's adjuvant (CFA)-induced inflammatory pain by suppression of P2X3 receptor

Ethnopharmacological relevanceScutellaria baicalensis Georgi (SBG) is a perennial herb with anti-inflammatory, antibacterial, and antioxidant activities, which is traditionally used to treat inflammation of respiratory tract and gastrointestinal tract, abdominal cramps, bacterial and viral infections. Clinically, it is often used to treat inflammatory-related diseases. Research has shown that the ethanol extract of Scutellaria baicalensis Georgi (SGE) has anti-inflammatory effect, and its main components baicalin and baicalein have analgesic effects. However, the mechanism of SGE in relieving inflammatory pain has not been deeply studied. Aim of the studyThis study aimed to evaluate the analgesic effect of SGE on complete Freund's adjuvant (CFA)-induced inflammatory pain rats, and to investigate whether its effect on relieving inflammatory pain is associated with regulation of P2X3 receptor. Materials and methodsThe analgesic effects of SGE on CFA-induced inflammatory pain rats were evaluated by measuring mechanical pain threshold, thermal pain threshold, and motor coordination ability. The mechanisms of SGE in relieving inflammatory pain were explored by detecting inflammatory factors levels, NF-κB, COX-2 and P2X3 expression, and were further verified by addition of P2X3 receptor agonist (α, β me-ATP). ResultsOur results revealed that SGE can notably increase the mechanical pain threshold and thermal pain threshold of CFA-induced inflammatory pain rats, and markedly alleviate the pathological damage in DRG. SGE could suppress the release of inflammatory factors including IL-1β, IL-6, TNF-α and restrain the expression of NF-κB, COX-2 and P2X3. Moreover, α, β me-ATP further exacerbated the inflammatory pain of CFA-induced rats, while SGE could markedly raise the pain thresholds and relieve inflammatory pain. SGE could attenuate the pathological damage, inhibit P2X3 expression, inhibit the elevation of inflammatory factors caused by α, β me-ATP. SGE can also inhibit NF-κB and ERK1/2 activation caused by α, β me-ATP, and inhibit the mRNA expression of P2X3, COX-2, NF-κB, IL-1β, IL-6 and TNF-α in DRG of rats induced by CFA coupled with α, β me-ATP. ConclusionsIn summary, our research indicated that SGE could alleviate CFA-induced inflammatory pain by suppression of P2X3 receptor.

The deubiquitinase OTUD4 inhibits the expression of antimicrobial peptides in Paneth cells to support intestinal inflammation and bacterial infection.

Dysfunction of the intestinal epithelial barrier causes microbial invasion that would lead to inflammation in the gut. Antimicrobial peptides (AMPs) are essential components of the intestinal epithelial barrier, while the regulatory mechanisms of AMPs expression are not fully characterized. Here, we report that the ovarian tumor family deubiquitinase 4 (OTUD4) in Paneth cells restricts the expression of AMPs and thereby promotes experimental colitis and bacterial infection. OTUD4 is upregulated in the inflamed mucosa of ulcerative colitis patients and in the colon of mice treated with dextran sulfate sodium salt (DSS). Knockout of OTUD4 promotes the expression of AMPs in intestinal organoids after stimulation with lipopolysaccharide (LPS) or peptidoglycan (PGN) and in the intestinal epithelial cells (IECs) of mice after DSS treatment or Salmonella typhimurium (S.t.) infection. Consistently, Vil-Cre;Otud4fl/fl mice and Def-Cre;Otud4fl/fl mice exhibit hyper-resistance to DSS-induced colitis and S.t. infection compared to Otud4fl/fl mice. Mechanistically, knockout of OTUD4 results in hyper K63-linked ubiquitination of MyD88 and increases the activation of NF-κB and MAPKs to promote the expression of AMPs. These findings collectively highlight an indispensable role of OTUD4 in Paneth cells to modulate AMPs production and indicate OTUD4 as a potential target for gastrointestinal inflammation and bacterial infection.

Comparison of Source Attribution Methodologies for Human Campylobacteriosis.

Campylobacter spp. are the most common cause of bacterial gastrointestinal infection in humans both in Denmark and worldwide. Studies have found microbial subtyping to be a powerful tool for source attribution, but comparisons of different methodologies are limited. In this study, we compare three source attribution approaches (Machine Learning, Network Analysis, and Bayesian modeling) using three types of whole genome sequences (WGS) data inputs (cgMLST, 5-Mers and 7-Mers). We predicted and compared the sources of human campylobacteriosis cases in Denmark. Using 7mer as an input feature provided the best model performance. The network analysis algorithm had a CSC value of 78.99% and an F1-score value of 67%, while the machine-learning algorithm showed the highest accuracy (98%). The models attributed between 965 and all of the 1224 human cases to a source (network applying 5mer and machine learning applying 7mer, respectively). Chicken from Denmark was the primary source of human campylobacteriosis with an average percentage probability of attribution of 45.8% to 65.4%, representing Bayesian with 7mer and machine learning with cgMLST, respectively. Our results indicate that the different source attribution methodologies based on WGS have great potential for the surveillance and source tracking of Campylobacter. The results of such models may support decision makers to prioritize and target interventions.

A Case of X-Linked Moesin-Associated Immune Deficiency in a Pediatric Patient

BackgroundX-Linked Moesin-Associated Immune Deficiency (X-MAID) is a rare severe combined immunodeficiency (SCID) subtype that can present at any age due to its variability. Depending on severity, patients demonstrate failure to thrive, recurrent bacterial and viral infections, and increased susceptibility to varicella zoster. It has been characterized by marked lymphopenia with hypogammaglobulinemia and impaired T-cell migration and proliferation. Case PresentationThis is a report of a Cuban 7-year-old male with poor weight gain and facial dysmorphia. He had a history of recurrent bacterial gastrointestinal infections and pneumonia beginning at 4 months of age. He additionally had 4–6 upper respiratory tract and ear infections annually. While still living in Cuba, he was admitted for a profound EBV infection in the setting of significant leukopenia. A bone marrow biopsy confirmed no malignancy. After he moved to the United States, his laboratory work-up revealed marked leukopenia with low absolute neutrophil and lymphocyte count with low T and B cells, very low immunoglobulin levels IgG, IgA, and IgM, and poor vaccination responses to streptococcus pneumonia, varicella zoster, and SARS-CoV-2. Genetic testing revealed a missense pathogenic variant c.511C>T (p.Arg171Trp) in the moesin (MSN) gene associated with X-MAID. He was managed with Bactrim and acyclovir prophylaxis, and immunoglobulin replacement therapy, and considered for hematopoietic stem cell transplantation. DiscussionDiagnosis of X-MAID should be considered in patients with recurrent infections and profound lymphopenia. As with SCID, early diagnosis and intervention is of utmost importance to prevent morbidity and mortality. This case demonstrates the importance of genetic testing in identifying this disease as it may prompt an immunologist to consider HSCT if conservative management is suboptimal. In the current literature, HSCT appears promising, but the long-term outcomes have yet to be described.

Oral exposure to Escherichia colitoxin protects against lung allergen-induced inflammation

Abstract Recent studies suggest that the intestinal microenvironment regulate lung immune cells. Conversely, changes in the lung can modulate the gut immune system. Yet, mucosal-associated immune responses have been studied in a compartmentalized manner, as if there is no communication between different organs. Thus, the role of the gut-lung axis in mucosal immune responses is poorly understood. Using enterotoxigenic Escherichia coli (ETEC), we established a model of intestine-localized infection without translocation to any other tissue. In response to ETEC, type 2 innate lymphoid cells (ILC2s) and eosinophils accumulated in the intestinal lamina propria, even after bacterial clearance. In addition, oral ETEC transiently increased the numbers of ILC2 and eosinophils in the lung parenchyma. To test if oral ETEC promote lung immune responses to allergen, we exposed mice that recently cleared ETEC to intranasal papain/ovalbumin allergy induction model. Unexpectedly, ETEC-exposed mice were significantly resistant to allergen-induced lung inflammation, with reduced number of ILC2, Type 2 effector CD4 +T cells (Th2) and eosinophils. Paradoxically, oral ETEC-induced protection against lung allergen exposure was dependent on IL-33: IL-33KO mice developed partial lung inflammation in this model, and no protection induced by ETEC exposure was observed. Importantly, protection from allergy was achieved with ETEC heat-labile toxin (LT) oral exposure; we also found that the toxicity domain of LT is needed for this protection. Our results indicate that gastrointestinal bacterial infection mediators (toxins) negatively regulate the onset of allergic inflammation and may provide a novel immunological basis for the “hygiene hypothesis”. R01AI170649 FAPESP 2021/15185-2

Fabrication of pH-Responsive Chitosan/Polyvinylpyrrolidone Hydrogels for Controlled Release of Metronidazole and Antibacterial Properties

This research focused on preparing hydrogels with controlled drug release properties to control gastrointestinal tract bacterial infection. Chitosan (CS) and polyvinylpyrrolidone (PVP) were used as the base polymers, with the CS component crosslinked by glutaraldehyde for hydrogel preparation using the solution casting technique. The effect of varying glutaraldehyde content in the hydrogels was characterized by the extent of swelling in simulated physiological fluids of pH 1.2, 6.8, and 7.4; the development of porosity; and gel fraction. Functional groups and covalent and hydrogen bonds formed, thermal stability, phase structure, and morphology were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The results show that the components in the hydrogels have good compatibility and formed honeycomb-like structures. In vitro studies confirmed that the hydrogels have good biodegradability at pH 7.4. Based on these properties, a CS/PVP hydrogel of the ratio of 60 : 40 crosslinked with 600 μL glutaraldehyde was selected for the in-situ loading of 200 mg of the drug metronidazole (MTZ). The hydrogel was characterized for cumulative drug release in the simulated physiological fluids and drug release kinetics using different models and for its antibacterial activity. The best-fit Korsmeyer–Peppas model suggests that MTZ release followed diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This hydrogel displays enhanced antimicrobial activity against Staphylococcus aureus, and Escherichia coli showed substantial inhibition zones indicating the produced CS/PVP hydrogels are promising candidates for controlled drug release applications.

The Antibacterial Activity of Dayak Onion Ethanol Extract (Eleutherine Palmifolia (L.) Merr) and Red Ginger (Zingiber Officinale Rosc Var. Rubrum) on Growth Gi Tract Pathogen Bacteria

Antibiotic resistance in gastrointestinal bacterial infections can be overcome by alternatives using medicinal plants such as Dayak bulbs (Eleutherine palmifolia (L.) Merr) and red ginger rhizome (Zingiber officinale Rosc. Var. Rubrum). This study aims to examine the antibacterial activity of a combination of ethanol extracts of Dayak bulbs with red ginger rhizomes and the effectiveness of the extract combinations in inhibiting the growth of Pseudomonas sp. and Bacillus sp. This research is an experimental study with a completely randomized design (CRD) of one factor, namely a combination of ethanol extract of Dayak onion tubers and red ginger rhizomes with 4 variations of concentration 25, 50, 75, and 100 mg/mL at 2 ratios of the combination of 2:1 and 3:1 for 48 experimental units. Tests were carried out on bacteria Pseudomonas sp. and Bacillus sp. in vitro with agar diffusion technique (Kirby Bauer test), while the positive control was Chloramphenicol 30 μg / mL and the negative controls were sterile aquadest. Data analysis in this study used the ANOVA test. The results showed ethanol extract of dayak onion bulbs, red ginger rhizomes, and a combination of the two extracts have antibacterial activity so which can be inhibiting the growth of Pseudomonas sp. and Bacillus sp. The combination of ethanol extract from dayak onion bulbs and has the greatest antibacterial activity at a 3:1 combination of 56.95% against the growth of Pseudomonas sp. and 109.72% against the growth of Bacillus sp.

Whole-genome-based characterization of Campylobacter jejuni from human patients with gastroenteritis collected over an 18 year period reveals increasing prevalence of antimicrobial resistance.

Campylobacteriosis is the most common cause of acute gastrointestinal bacterial infection in Europe, with most infections linked to the consumption of contaminated food. While previous studies found an increasing rate of antimicrobial resistance (AMR) in Campylobacter spp. over the past decades, the investigation of additional clinical isolates is likely to provide novel insights into the population structure and mechanisms of virulence and drug resistance of this important human pathogen. Therefore, we combined whole-genome sequencing and antimicrobial-susceptibility testing of 340 randomly selected Campylobacter jejuni isolates from humans with gastroenteritis, collected in Switzerland over an 18 year period. In our collection, the most common multilocus sequence types (STs) were ST-257 (n=44), ST-21 (n=36) and ST-50 (n=35); the most common clonal complexes (CCs) were CC-21 (n=102), CC-257 (n=49) and CC-48 (n=33). High heterogeneity was observed among STs, with the most abundant STs recurring over the entire study period, while others were observed only sporadically. Source attribution based on ST assigned more than half of the strains to the 'generalist' category (n=188), 25 % as 'poultry specialist' (n=83), and only a few to 'ruminant specialist' (n=11) or 'wild bird' origin (n=9). The isolates displayed an increased frequency of AMR from 2003 to 2020, with the highest rates of resistance observed for ciprofloxacin and nalidixic acid (49.8 %), followed by tetracycline (36.9 %). Quinolone-resistant isolates carried chromosomal gyrA mutations T86I (99.4 %) and T86A (0.6 %), whereas tetracycline-resistant isolates carried tet(O) (79.8 %) or mosaic tetO/32/O (20.2 %) genes. A novel chromosomal cassette carrying several resistance genes, including aph(3')-III, satA and aad(6), and flanked by insertion sequence elements was detected in one isolate. Collectively, our data revealed an increasing prevalence of resistance to quinolones and tetracycline in C. jejuni isolates from Swiss patients over time, linked to clonal expansion of gyrA mutants and acquisition of the tet(O) gene. Investigation of source attribution suggests that infections are most likely related to isolates from poultry or generalist backgrounds. These findings are relevant to guide future infection prevention and control strategies.

Reactive arthritis

Reactive arthritis Abstract. Reactive Arthritis is a sterile, inflammatory arthritis that is typically preceded by a bacterial gastrointestinal or urogenital infection occurring one to four weeks previously. The typical pattern is an asymmetric oligoarthritis most common affecting the lower extremities. Similar to other spondyloarthropathies, enthesitis, dactylitis, and sacroiliitis can occur as well as extra-articular manifestations, such as conjunctivitis, anterior uveitis, oral ulcers, circinate balanitis, and keratoderma blennorrhagicum. The treatment of "triggering" infection with antibiotics is the first therapeutic goal, especially for Chlamydia trachomatis. For arthritis NSAIDs are the treatment of first choice, followed by intraarticular or oral glucocorticosteroids. DMARDs (Sulfasalzine, TNF-alpha inhibitors) are reserved for refractory cases. Over 50% of the patients have a self-limited course lasting two to six months, 30% have recurrent episodes, and 10-20% have a chronic course requiring immunosuppressive therapy.

Raw potato starch alters the microbiome, colon and cecal gene expression, and resistance to Citrobacter rodentium infection in mice fed a Western diet.

Resistant starches (RS) are fermented in the cecum and colon to produce short-chain fatty acids and other microbial metabolites that can alter host physiology and the composition of the microbiome. We previously showed that mice fed a Total Western Diet (TWD) based on NHANES data that mimics the composition of a typical American diet, containing resistant potato starch (RPS), produced concentration dependent changes to the cecal short-chain fatty acids, the microbiome composition as well as gene expression changes in the cecum and colon that were most prevalent in mice fed the 10% RPS diet. We were then interested in whether feeding TWD/RPS would alter the resistance to bacterial-induced colitis caused by Citrobacter rodentium (Cr), a mouse pathogen that shares 66.7% of encoded genes with Enteropathogenic Escherichia coli. Mice were fed the TWD for 6 weeks followed by a 3-weeks on the RPS diets before infecting with Cr. Fecal Cr excretion was monitored over time and fecal samples were collected for 16S sequencing. Mice were euthanized on day 12 post-infection and cecal contents collected for 16S sequencing. Cecum and colon tissues were obtained for gene expression analysis, histology and to determine the level of mucosa-associated Cr. Feeding RPS increased the percentage of mice productively infected by Cr and fecal Cr excretion on day 4 post-infection. Mice fed the TWD/10% RPS diet also had greater colonization of colonic tissue at day 12 post-infection and colonic pathology. Both diet and infection altered the fecal and cecal microbiome composition with increased levels of RPS resulting in decreased α-diversity that was partially reversed by Cr infection. RNASeq analysis identified several mechanistic pathways that could be associated with the increased colonization of Cr-infected mice fed 10% RPS. In the distal colon we found a decrease in enrichment for genes associated with T cells, B cells, genes associated with the synthesis of DHA-derived SPMs and VA metabolism/retinoic acid signaling. We also found an increase in the expression of the potentially immunosuppressive gene, Ido1. These results suggest that high-level consumption of RPS in the context of a typical American diet, may alter susceptibility to gastrointestinal bacterial infections.

Antibiotic prescribing for acute gastroenteritis during ambulatory care visits-United States, 2006-2015.

To describe national antibiotic prescribing for acute gastroenteritis (AGE). Ambulatory care. We included visits with diagnoses for bacterial and viral gastrointestinal infections from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey (NAMCS/NHAMCS; 2006-2015) and the IBM Watson 2014 MarketScan Commercial Claims and Encounters Database. For NAMCS/NHAMCS, we calculated annual percentage estimates and 99% confidence intervals (CIs) of visits with antibiotics prescribed; sample sizes were too small to calculate estimates by pathogen. For MarketScan, we used Poisson regression to calculate the percentage of visits with antibiotics prescribed and 95% CIs, including by pathogen. We included 10,210 NAMCS/NHAMCS AGE visits; an estimated 13.3% (99% CI, 11.2%-15.4%) resulted in antibiotic prescriptions, most frequently fluoroquinolones (28.7%; 99% CI, 21.1%-36.3%), nitroimidazoles (20.2%; 99% CI, 14.0%-26.4%), and penicillins (18.9%; 99% CI, 11.6%-26.2%). In NAMCS/NHAMCS, antibiotic prescribing was least frequent in emergency departments (10.8%; 99% CI, 9.5%-12.1%). Among 1,868,465 MarketScan AGE visits, antibiotics were prescribed for 13.8% (95% CI, 13.7%-13.8%), most commonly for Yersinia (46.7%; 95% CI, 21.4%-71.9%), Campylobacter (44.8%; 95% CI, 41.5%-48.1%), Shigella (39.7%; 95% CI, 35.9%-43.6%), typhoid or paratyphoid fever (32.7%; (95% CI, 27.2%-38.3%), and nontyphoidal Salmonella (31.7%; 95% CI, 29.5%-33.9%). Antibiotics were prescribed for 12.3% (95% CI, 11.7%-13.0%) of visits for viral gastroenteritis. Overall, ∼13% of AGE visits resulted in antibiotic prescriptions. Antibiotics were unnecessarily prescribed for viral gastroenteritis and some bacterial infections for which antibiotics are not recommended. Antibiotic stewardship assessments and interventions for AGE are needed in ambulatory settings.