Human Gastrointestinal Diseases Research Articles

Mechanisms of Amomum villosum essential oil in enhancing tilapia (Oreochromis niloticus) intestinal health

Amomum villosum is a member of the ginger family to treat gastrointestinal diseases in humans. Supplementing the diet of tilapia (Oreochromis niloticus) with essential oil (EOA) can enhance digestive and intestinal antioxidant capacity. We conducted a comparative experiment using tilapia to further understand the potential molecular response mechanism to dietary EOA. Fish were divided into four groups with different feeding doses of EOA: L (2 g/Kg) group, M (4 g/Kg) group, and H (8 g/Kg) group, along with a control group without EOA supplementation. The level of inflammatory factors (TNF-α, IL-1) declined significantly in the EOA group. Comparative transcriptome of the intestines revealed differentially expressed genes (DEGs) in each group, which further revealed that enriched terms were closely related to important pathways such as PI3K-Akt signaling, cell adhesion molecules, regulation of actin cytoskeleton, and autoimmune thyroid disease. These pathways play significant roles in regulating various cellular processes and immune responses of intestines. Intestine metabolomic analysis indicated that dietary EOA caused changes in metabolic processes, particularly in nucleotide metabolism, indicating the potential impact of EOA on these processes. To identify key factors regulating the molecular response to EOA supplementation, a weighted gene co-expression network analysis combined with transcriptome and differential metabolites to identify key genes and metabolites. Glycitein and genistein are substances related to the metabolism of soybean meal were identified. Hmgb2, Parp11, Bcoll is considered to be the key genes, and has the immune regulation function. This study provides new insights into the molecular basis underlying the protective effects of dietary EOA in tilapia. The results can benefit the aquaculture industry by developing dietary strategies to improve the health and welfare of tilapia in intensive farming.

Design of a duplex Loop-mediated isothermal amplification assay suitable for real-time, and end-point, colorimetric detection of Vibrio parahaemolyticus, and a universal Internal Amplification Control, in mussel samples

Vibrio parahaemolyticus remains as one of the most important foodborne pathogens worldwide, causing gastrointestinal disease in humans due to the consumption of raw, or undercooked, seafood. Even though molecular techniques, like PCR and qPCR, have allowed to overcome most of the limitations associated to culture-based methods, some persist such as the need for highly trained personnel, or the need to acquire expensive equipment. Loop-mediated isothermal amplification, LAMP, has emerged as a promising tool to solve these issues. The present study reports the development of a novel LAMP-based method for the detection of V. parahaemolyticus in mussels. This assay targets the gene toxR, and implements a novel, universal, freely available Internal Amplification Control (IAC) which was detected in a multiplex real-time LAMP format, where it is differentiated by melt curve analysis (86.70 ± 0.32 °C and 90.24 ± 0.34 °C for toxR and IAC respectively) and did not impact the analytical sensitivity of the target. Alternatively, the IAC was also applied in a parallel reaction and the assays performed by end-point, colorimetric LAMP. This novel IAC allowed to identify reaction inhibition due to matrix effect, and rule out false negative results. This new assay was combined with the ISO 21872 enrichment protocol, and the evaluation of spiked mussel samples indicated that an LOD95 of 14.5 and 10.8 CFU/25g could be reached after the primary 6h and secondary 24h enrichment steps by real-time LAMP, and 27.9 and 10.9 CFU/25g by naked-eye, color LAMP. It was important to note that in addition to these differences in terms of LOD95, a higher number of samples presenting reaction inhibition was observed after the primary enrichment, compared to the secondary, all successfully identified thanks to the new IAC; and also that statistically longer amplification times were required (Cq values of 19.47 ± 7.87 and 7.90 ± 1.20 respectively). The overall evaluation of the method returned values of diagnostic sensitivity, specificity and accuracy of 100 % along with an index of concordance of 1.00. These results were consistent regardless if the real-time, or the colorimetric, LAMP strategy was followed.

A one health study on phylogenetics and risk of pathogenic intestinal parasites at a ranch in Inner Mongolia

Cryptosporidium, Giardia duodenalis, and Enterocytozoon bieneusi are widespread zoonotic pathogens causing gastrointestinal diseases in humans and various animal species. Inner Mongolia, a major beef production region in China, there is a notable absence of comprehensive research on intestinal parasitism. Thus, timely and comprehensive diagnosis is essential to mitigate disease spread and minimize economic losses in the livestock industry. In this study, we collected fecal samples from cattle and humans, as well as soil and water samples, and all samples were tested for pathogenic intestinal protozoa at the Simmental cattle ranch in Wengniute, Chifeng City, Inner Mongolia. Among the 393 samples tested, 76/371 (20.5 %) cattle, 6/11 (54.5 %) ranch workers, 1/7 (14.3 %) water, and 2/4 (50 %) soil samples were positive. Factors affecting the infection rate of intestinal protozoa were examined. Results showed that the infection rate was higher in June than in January, higher in calves than in adults, and higher in diarrheal calves than in healthy calves. Additionally, the infection rate of intestinal protozoa was higher in pathogen-contaminated water source sheds than in uncontaminated sheds. Genetic and evolutionary analyses revealed that the prevalent E. bieneusi subtypes are predominantly J, I, and BEB4, while the G. duodenalis subtypes are assemblages B and E. The Cryptosporidium species identified were C. bovis, C. andersoni, C. parvum, C. ryanae, and C. suis, with C. parvum being a notable zoonotic pathogen. The pathogen sequences from humans, cattle, water, and soil showed 99–100 % similarity, suggesting possible transmission or contamination between animals and the environment. This study contributes to the One Health approach by addressing the gap in research on intestinal protozoa in Inner Mongolia. It provides important data for other ranches in the region to understand the prevalence of such pathogens and develop effective control measures. Using the concept of One Health to analyze the spatiotemporal distribution of intestinal protozoa in pastures is of great significance for maintaining public health.

Host-Pathogen Interactions during Shiga Toxin-Producing Escherichia coli Adherence and Colonization in the Bovine Gut: A Comprehensive Review.

Shiga toxin-producing Escherichia coli (STEC) is a significant public health threat due to its ability to cause severe gastrointestinal diseases in humans, ranging from diarrhea to life-threatening conditions such as hemorrhagic colitis and hemolytic uremic syndrome (HUS). As the primary reservoir of STEC, cattle play a crucial role in its transmission through contaminated food and water, posing a considerable risk to human health. This comprehensive review explores host-pathogen interactions during STEC colonization of the bovine gut, focusing on the role of gut microbiota in modulating these interactions and influencing disease outcomes. We integrated findings from published transcriptomics, proteomics, and genomics studies to provide a thorough understanding of how STEC adheres to and colonizes the bovine gastrointestinal tract. The insights from this review offer potential avenues for the development of novel preventative and therapeutic strategies aimed at controlling STEC colonization in cattle, thereby reducing the risk of zoonotic transmission.

Exploring the anti-protozoal mechanisms of Syzygium aromaticum phytochemicals targeting Cryptosporidium parvum lactate dehydrogenase through molecular dynamics simulations

Cryptosporidium parvum (C. parvum), a protozoan parasite, is known to induce significant gastrointestinal disease in humans. Lactate dehydrogenase (LDH), a protein of C. parvum, has been identified as a potential therapeutic target for developing effective drugs against infection. This study utilized a computational drug discovery approach to identify potential drug molecules against the LDH protein of C. parvum. In the present investigation, we conducted a structure-based virtual screening of 55 phytochemicals from the Syzygium aromaticum (S. aromaticum). This process identified four phytochemicals, including Gallotannin 23, Eugeniin, Strictinin, and Ellagitannin, that demonstrated significant binding affinity and dynamic stability with LDH protein. Interestingly, these four compounds have been documented to possess antibacterial, antiviral, anti-inflammatory, and antioxidant properties. The docked complexes were simulated for 100 ns using Desmond to check the dynamic stability. Finally, the free binding energy was computed from the last 10ns MD trajectories. Gallotannin 23 and Ellagitannin exhibited considerable binding affinity and stability with the target protein among all four phytochemicals. These findings suggest that these predicted phytochemicals from S. aromaticum could be further explored as potential hit candidates for developing effective drugs against C. parvum infection. The in vitro and in vivo experimental validation is still required to confirm their efficacy and safety as LDH inhibitors.

GastroFuse-Net: an ensemble deep learning framework designed for gastrointestinal abnormality detection in endoscopic images.

Convolutional Neural Networks (CNNs) have received substantial attention as a highly effective tool for analyzing medical images, notably in interpreting endoscopic images, due to their capacity to provide results equivalent to or exceeding those of medical specialists. This capability is particularly crucial in the realm of gastrointestinal disorders, where even experienced gastroenterologists find the automatic diagnosis of such conditions using endoscopic pictures to be a challenging endeavor. Currently, gastrointestinal findings in medical diagnosis are primarily determined by manual inspection by competent gastrointestinal endoscopists. This evaluation procedure is labor-intensive, time-consuming, and frequently results in high variability between laboratories. To address these challenges, we introduced a specialized CNN-based architecture called GastroFuse-Net, designed to recognize human gastrointestinal diseases from endoscopic images. GastroFuse-Net was developed by combining features extracted from two different CNN models with different numbers of layers, integrating shallow and deep representations to capture diverse aspects of the abnormalities. The Kvasir dataset was used to thoroughly test the proposed deep learning model. This dataset contained images that were classified according to structures (cecum, z-line, pylorus), diseases (ulcerative colitis, esophagitis, polyps), or surgical operations (dyed resection margins, dyed lifted polyps). The proposed model was evaluated using various measures, including specificity, recall, precision, F1-score, Mathew's Correlation Coefficient (MCC), and accuracy. The proposed model GastroFuse-Net exhibited exceptional performance, achieving a precision of 0.985, recall of 0.985, specificity of 0.984, F1-score of 0.997, MCC of 0.982, and an accuracy of 98.5%.

Comparative genomics of Cryptosporidium parvum reveals the emergence of an outbreak-associated population in Europe and its spread to the United States.

The zoonotic parasite Cryptosporidium parvum is a global cause of gastrointestinal disease in humans and ruminants. Sequence analysis of the highly polymorphic gp60 gene enabled the classification of C. parvum isolates into multiple groups (e.g., IIa, IIc, Id) and a large number of subtypes. In Europe, subtype IIaA15G2R1 is largely predominant and has been associated with many water- and food-borne outbreaks. In this study, we generated new whole-genome sequence (WGS) data from 123 human- and ruminant-derived isolates collected in 13 European countries and included other available WGS data from Europe, Egypt, China, and the United States (n = 72) in the largest comparative genomics study to date. We applied rigorous filters to exclude mixed infections and analyzed a data set from 141 isolates from the zoonotic groups IIa (n = 119) and IId (n = 22). Based on 28,047 high-quality, biallelic genomic SNPs, we identified three distinct and strongly supported populations: Isolates from China (IId) and Egypt (IIa and IId) formed population 1; a minority of European isolates (IIa and IId) formed population 2; and the majority of European (IIa, including all IIaA15G2R1 isolates) and all isolates from the United States (IIa) clustered in population 3. Based on analyses of the population structure, population genetics, and recombination, we show that population 3 has recently emerged and expanded throughout Europe to then, possibly from the United Kingdom, reach the United States, where it also expanded. The reason(s) for the successful spread of population 3 remain elusive, although genes under selective pressure uniquely in this population were identified.

The biology and pathogenicity of Clostridium perfringens type F: a common human enteropathogen with a new(ish) name.

SUMMARYIn the 2018-revised Clostridium perfringens typing classification system, isolates carrying the enterotoxin (cpe) and alpha toxin genes but no other typing toxin genes are now designated as type F. Type F isolates cause food poisoning and nonfoodborne human gastrointestinal (GI) diseases, which most commonly involve type F isolates carrying, respectivefooly, a chromosomal or plasmid-borne cpe gene. Compared to spores of other C. perfringens isolates, spores of type F chromosomal cpe isolates often exhibit greater resistance to food environment stresses, likely facilitating their survival in improperly prepared or stored foods. Multiple factors contribute to this spore resistance phenotype, including the production of a variant small acid-soluble protein-4. The pathogenicity of type F isolates involves sporulation-dependent C. perfringens enterotoxin (CPE) production. C. perfringens sporulation is initiated by orphan histidine kinases and sporulation-associated sigma factors that drive cpe transcription. CPE-induced cytotoxicity starts when CPE binds to claudin receptors to form a small complex (which also includes nonreceptor claudins). Approximately six small complexes oligomerize on the host cell plasma membrane surface to form a prepore. CPE molecules in that prepore apparently extend β-hairpin loops to form a β-barrel pore, allowing a Ca2+ influx that activates calpain. With low-dose CPE treatment, caspase-3-dependent apoptosis develops, while high-CPE dose treatment induces necroptosis. Those effects cause histologic damage along with fluid and electrolyte losses from the colon and small intestine. Sialidases likely contribute to type F disease by enhancing CPE action and, for NanI-producing nonfoodborne human GI disease isolates, increasing intestinal growth and colonization.

Trends in Nationally Notifiable Infectious Diseases in Humans and Animals during COVID-19 Pandemic, South Korea.

We investigated trends in notifiable infectious diseases in both humans and animals during the COVID-19 pandemic in South Korea and compared those data against expected trends had nonpharmaceutical interventions (NPIs) not been implemented. We found that human respiratory infectious diseases other than COVID-19 decreased by an average of 54.7% after NPIs were introduced. On the basis of that trend, we estimated that annual medical expenses associated with respiratory infections other than COVID-19 also decreased by 3.8% in 2020 and 18.9% in 2021. However, human gastrointestinal infectious diseases and livestock diseases exhibited similar or even higher incidence rates after NPIs were instituted. Our investigation revealed that the preventive effect of NPIs varied among diseases and that NPIs might have had limited effectiveness in reducing the spread of certain types of infectious diseases. These findings suggest the need for future, novel public health interventions to compensate for such limitations.

Meta-analysis on the global prevalence of Arcobacter in food-producing animals and humans

The genus Arcobacter has been associated with illnesses in both animals and humans, where Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii have been linked to numerous cases of gastrointestinal diseases in humans. While isolated instances of Arcobacter infection have been reported in certain areas, comprehensive data reflecting the global impact of Arcobacter infection are lacking. This meta-analysis was conducted with the objective of assessing the aggregated prevalence of Arcobacter across diverse sources on a global scale. We conducted a thorough literature search of the Scopus, PubMed, and ScienceDirect databases to identify studies published from 1992 to 2022 on Arcobacter prevalence in humans and food-producing animals. We utilized multilevel random effects meta-analysis models to gauge the average occurrence of Arcobacter and to examine various factors that could influence incidence outcomes. Seventy-five articles were included in the meta-analysis. The pooled prevalence of Arcobacter spp. from different sources was 21.9% (95% CI: 18.0%–26.1%), and the mean prevalence of A. butzleri, A. cryaerophilus, and A. skirrowii was 15.1%, 2.8%, and 0.1%, respectively. Arcobacter spp. had the lowest prevalence in humans (1.8%; 95% CI: 0.7%–3.3%) and the highest in broilers (38.8%; 95% CI: 28.0%–50.1%). Among animal-derived food products, carcasses or carcass parts exhibited the highest Arcobacter spp. prevalence of 28.6% (28.6%; 95% CI: 23.7%–33.7%). This meta-analysis revealed that A. butzleri is the most prevalent Arcobacter species worldwide, with broilers, as well as seafood, being the primary hosts of Arcobacter spp. We recommend developing appropriate prevention strategies and conducting further local in-depth studies to establish the actual epidemiological burden of Arcobacter.

Shiga Toxin-Producing Escherichia coli Testing in New York 2011-2022 Reveals Increase in Non-O157 Identifications.

Shiga toxin-producing Escherichia coli (STEC) are an important cause of bacterial enteric infection. STEC strains cause serious human gastrointestinal disease, which may result in life-threatening complications such as hemolytic uremic syndrome. They have the potential to impact public health due to diagnostic challenges of identifying non-O157 strains in the clinical laboratory. The Wadsworth Center (WC), the public health laboratory of the New York State Department of Health, has isolated and identified non-O157 STEC for decades. A shift from initially available enzyme immunoassay testing to culture-independent diagnostic tests (CIDTs) has increased the uptake of testing at clinical microbiology laboratories. This testing change has resulted in an increased number of specimen submissions to WC. During a 12-year period between 2011 and 2022, WC received 5037 broths and/or stool specimens for STEC confirmation from clinical microbiology laboratories. Of these, 3992 were positive for Shiga toxin genes (stx1 and/or stx2) by real-time PCR. Furthermore, culture methods were utilized to isolate, identify, and characterize 2925 STEC from these primary specimens. Notably, WC observed a >200% increase in the number of STEC specimens received in 2021-2022 compared with 2011-2012 and an 18% increase in the number of non-O157 STEC identified using the same methodologies. During the past decade, the WC testing algorithm has been updated to manage the increase in specimens received, while also navigating the novel COVID-19 pandemic, which took priority over other testing for a period of time. This report summarizes updated methods for confirmation, surveillance, and outbreak detection of STEC and describes findings that may be related to our algorithm updates and the increased use of CIDTs, which is starting to elucidate the true incidence of non-O157 STEC.

Neonatal Calf Diarrhea and Gastrointestinal Microbiota: Etiologic Agents and Microbiota Manipulation for Treatment and Prevention of Diarrhea.

Neonatal calf diarrhea is the leading cause of neonatal morbidity and mortality globally. The changes associated with the gastrointestinal microbiota in neonatal calves experiencing diarrhea and its etiology are not fully understood or completely defined in the literature. Several studies have demonstrated that the fecal microbiota of calves that experience diarrhea substantially deviates from that of healthy age-matched calves. However, one key question remains: whether the changes observed in the bacterial communities (also known as dysbiosis) are a predisposing factor for, or the consequence of, gastrointestinal inflammation caused by the pathogens associated with calf diarrhea. The first objective of this literature review is to present the current information regarding the changes in the fecal microbiota of diarrheic calves and the impact of the pathogens associated with diarrhea on fecal microbiota. Modulation of the gastrointestinal microbiota using pre- and probiotics, colostrum feeding, and fecal microbiota transplantation (FMT) has been used to treat and prevent gastrointestinal diseases in humans and dogs. Although information regarding the use of probiotics for the prevention of diarrhea is available in cattle, little information is available regarding the use of these strategies for treating calf diarrhea and the use of prebiotics or FMT to prevent diarrhea. The second objective of this literature review is to summarize the current knowledge regarding the impact of prebiotics, probiotics, synbiotics, colostrum feeding, and FMT for the treatment and prevention of calf diarrhea.

A non-human primate model for human norovirus infection.

Norovirus infection can cause gastrointestinal disease in humans. Development of therapies and vaccines against norovirus have been limited by the lack of a suitable and reliable animal model. Here we established rhesus macaques as an animal model for human norovirus infection. We show that rhesus macaques are susceptible to oral infection with human noroviruses from two different genogroups. Variation in duration of virus shedding (days to weeks) between animals, evolution of the virus over the time of infection, induction of virus-specific adaptive immune responses, susceptibility to reinfection and preferential replication of norovirus in the jejunum of rhesus macaques was similar to infection reported in humans. We found minor pathological signs and changes in epithelial cell surface glycosylation patterns in the small intestine during infection. Detection of viral protein and RNA in intestinal biopsies confirmed the presence of the virus in chromogranin A-expressing epithelial cells, as it does in humans. Thus, rhesus macaques are a promising non-human primate model to evaluate vaccines and therapeutics against norovirus disease.

A Bifidobacterium animalis subsp. lactis strain that can suppress Helicobacter pylori: isolation, in vitro and in vivo validation.

The administration of probiotics is an effective approach for treatment of Helicobacter pylori, which is associated with human gastrointestinal diseases and cancers. To explore more effective probiotics for H. pylori infection elimination, bacteria from infant feces were screened in this study. We successfully isolated the Bifidobacterium animalis subsp. lactis strains and evaluated its efficacy to inhibit H. pylori growth in vitro and in vivo. The results showed that a B. animalis strain (named BB18) sustained a high survival rate after incubation in gastric juice. The rapid urease test suggested that B. animalis BB18 reduced pathogen loads in H. pylori-infected Mongolian gerbils. Alleviation of H. pylori infection-induced gastric mucosa damage and decreased levels inflammatory cytokines were observed after the B. animalis BB18 administration. These findings demonstrated that B. animalis BB18 can inhibit H. pylori infection both in vitro and in vivo, suggesting its potential application for the prevention and eradication therapy of H. pylori infection.

Novel toxin-based mRNA vaccine against Clostridium perfringens using in silico approaches

Clostridium perfringens is a bacterium that causes gastrointestinal diseases in humans and animals. The several powerful toxins such as alpha toxin (CPA), beta toxin (CPB), enterotoxin (CPE), Epsilon toxin (ETX), and theta toxin, play a major role in its pathogenesis. Traditional vaccine development methods are time-consuming and costly. In silico approaches offer an alternative strategy for designing vaccines by analyzing biological data and predicting immunogenic peptides. In this study, computational tools were utilized to design a RNA vaccine targeting C. perfringens toxins. Toxin protein sequences were retrieved and their linear B-cell, MHCI, and MHCII binding epitopes were predicted. Allergenicity, toxigenicity, and IFN-γ induction were assessed to select non-allergenic, non-toxic, and IFN-γ-inducing epitopes. Molecular docking was performed to identify epitopes that fit within the binding cleft of MHC alleles. A final peptide vaccine construct was designed with selected epitopes separated by a linker sequence. The antigenicity and physicochemical properties of the vaccine were evaluated. Immune response simulation showed enhanced secondary and tertiary immune responses, increased levels of immunoglobulins, cytotoxic T lymphocytes, helper T lymphocytes, macrophage activity, and elevated levels IFN-γ and interleukin-2. Docking analysis was done to assess interactions between the vaccine structure and Toll-like receptors. Codon optimization was performed, and a final RNA vaccine construct was designed. The secondary structure of the RNA vaccine was predicted and validated. Overall, this study demonstrates the potential of in silico approaches for designing an RNA vaccine against C. perfringens toxins, contributing to improved prevention and control of associated diseases.

Occurrence of Florfenicol and Linezolid Resistance and Emergence of optrA Gene in Campylobacter coli Isolates from Tunisian Avian Farms.

Campylobacter species, especially C. coli and C. jejuni, have been associated with a range of human gastrointestinal diseases. During the last two decades, due to the irrational use of antibiotics in poultry farms, high rates of antimicrobial resistance have been globally reported in C. coli and C. jejuni isolates. Recently, acquired linezolid-resistance mechanisms have been reported in Campylobacter spp. isolates, which is a cause of concern to human health. In this study, we performed a retrospective analysis of 139 C. coli isolates previously collected from broilers (n = 41), laying hens (n = 53), eggs (n = 4), and environment (n = 41) to detect acquired genes implicated in linezolid resistance. Isolates were tested for their susceptibility to antimicrobial agents using the Kirby-Bauer disk diffusion assay. Chloramphenicol- and linezolid-resistant isolates were subjected to PCR screening for the following genes: fexA, fexB, floR, RE-cmeABC, cfrA, and optrA. The genetic relatedness of eight multidrug-resistant isolates was determined by multilocus sequence typing (MLST). Among the 139 C. coli isolates, high rates of resistance (57.55%-100%) were detected toward nalidixic acid, ciprofloxacin, erythromycin, azithromycin, ampicillin, chloramphenicol, linezolid, and kanamycin. Among 135 chloramphenicol-resistant isolates, the optrA, cfr, fexA floR, RE-cmeABC, and fexB genes were detected in 124 (124/135, 91.85%), 108 (80%), 105 (77.7%), 64 (47.4%), 56 (41, 48%), and 27 (20%) isolates, respectively. In addition, the majority of isolates harbored more than one of these genes. The selected eight isolates belonged to the same sequence type ST13450, which is a new sequence type (ST), not belonging to ST828 and ST1150 complexes. In conclusion, the emergence of optrA gene in Campylobacter spp. isolates makes this genus an optrA reservoir and vector to other pathogens such as Staphylococcus aureus and Enterococcus spp., which is a cause of concern for human and animal health.

Molecular characterization of Enterocytozoon bieneusi genotypes in wild Altai marmot (Marmota baibacina) in Xinjiang, China: host specificity and adaptation.

Enterocytozoon bieneusi is responsible for opportunistic infections leading to gastrointestinal diseases in humans and animals worldwide. A total of 334 fresh fecal samples were collected from wild Altai marmots (Marmota baibacina) in Xinjiang, China, and E. bieneusi was screened via PCR amplification of the internal transcribed spacer (ITS) region of the small submit ribosomal RNA (SSU rRNA). The results indicated that 22.8% (76/334) of the wild Altai marmot fecal samples were positive for E. bieneusi, and the highest positive rate was detected in Akqi (51.9%, 27/52), with a significant difference from other sampling sites (p < 0.01). Four known genotypes (BEB6, CHG3, GX2, and YAK1) and three novel genotypes (XJHT2 to XJHT4) were identified in the present study. Genotype XJHT3 was dominant and detected in 48 fecal samples. In the phylogenetic analysis, the novel genotypes XJHT2 and XJHT3 were clustered in Group 1 together with the known genotype YAK1, while genotypes CHG3 and BEB6 were clustered in Group 2. The novel genotype XJHT4 was clustered together with other rodent-derived genotypes and generated a novel Group 14. These data confirmed the host specificity and adaptation of E. bieneusi in rodents. These findings enrich our understanding of the prevalence and genetic diversity of E. bieneusi in wild Altai marmots in Xinjiang, China.

A Single-laboratory Performance Evaluation of MALDI-TOF MS in Rapid Identification of Staphylococcus aureus, Cronobacter sakazakii, Vibrio parahaemolyticus, and Some Closely Related Bacterial Species of Public Health Importance.

Staphylococcus is a genus of Gram-positive bacteria, known to cause food poisoning and gastrointestinal illness in humans. Additionally, the emergence of methicillin-resistant S. aureus (MRSA) strains have caused major healthcare burden worldwide. Cronobacter is a group of Gram-negative bacteria, that can survive in extreme dry conditions. Cronobacter sakazakii is known to contaminate the powdered infant formula and cause life-threatening infections in neonates. Vibrio is a genus of human-pathogenic Gram-negative bacteria that can cause foodborne illness by consuming undercooked or raw seafood. Vibrio parahaemolyticus can cause serious gastrointestinal disease in humans. Thus, rapid identification of Staphylococcus spp., Cronobacter spp. and Vibrio spp. is crucial for the source tracking of contaminated food, and to measure the transmission dynamics of these bacterial pathogens causing foodborne diseases and outbreaks. This single-laboratory performance evaluation study used the VITEK MS system to evaluate the potential of MALDI-TOF MS technology for rapid identification of S. aureus-like, C. sakazakii-like, and V. parahaemolyticus-like, isolates of public health importance. A total of 226 isolates recovered from various food, environmental surveillance samples and other sources were identified by bioMérieux VITEK 2 and VITEK MS systems as Staphylococcus spp., Cronobacter spp., and Vibrio spp. Five American Type Culture Collection (ATCC) reference Gram-positive and Gram-negative bacterial isolates were also tested to complete the study. In addition, for some Staphylococcus spp. isolates whole genome sequencing (WGS), and DNA sequencing of 16S rRNA partial region was also performed for species identification. The VITEK MS system was able to provide species identification to all 96 isolates of Staphylococcus spp. and to all 29 isolates of Vibrio spp. examined with a high confidence value (99.9%). Similarly, species identification was observed for the majority of spots (245 of 303) for the 101 Cronobacter spp. isolates (∼82.0%) with a high confidence value (99.9%), and genus level identification was noticed for the rest of the Cronobacter spp. isolates (18.0%; 58 of the 303 spots) analyzed. Species identification data generated by VITEK 2 system was comparable to data obtained by VITEK MS system. The VITEK MS system is a reliable high-throughput platform that can rapidly identify Staphylococcus, Vibrio, and Cronobacter to the genus level, as well as S. aureus, C. sakazakii, V. parahaemolyticus, and other closely related foodborne isolates, and bacterial isolates from additional sources, in most cases. The VITEK MS system can be used in the rapid genus and species identification of human-pathogenic Staphylococcus spp., Cronobacter spp., and Vibrio spp. isolates.

Dihydromyricetin alleviates intestinal inflammation by changing intestinal microbial metabolites and inhibiting the expression of the MyD88/NF‐κB signaling pathway

AbstractInflammatory bowel disease (IBD), a common chronic gastrointestinal disease in humans, has emerged as a global public health challenge. Dihydromyricetin (DHM) has anti‐inflammatory and antioxidant activities, which can alleviate inflammation. In this study, we explored the effect and underlying mechanism of DHM on dextran sulfate sodium (DSS)‐induced colitis in mice and porcine jejunum epithelial cells (IPEC‐J2) exposed to lipopolysaccharide (LPS). We found that DHM alleviated loss of weight, diarrhea, and damage of colon structure in colitis mice. For the intestinal microbial, a significant rise in the amount of the potentially beneficial genera and a decline in the amount of harmful genera were observed in DHM‐treated colitis mice. Metabolomic analysis of cecal content revealed that DHM restored phenylalanine metabolism, arginine biosynthesis, and arachidonic acid metabolism disorders caused by intestinal inflammation. Moreover, DHM decreased the level of pro‐inflammatory cytokines and reactive oxygen species in LPS‐treated IPEC‐J2 cells. DHM also reduced the expression of MyD88 and nuclear factor‐κB (NF‐κB). In summary, we found that 125 mg/kg DHM administration alleviated diarrhea, reinstated intestinal barrier function, modulated intestinal dysbiosis, and suppressed the expression of myeloid differentiation factor 88 (MyD88) and NF‐κB. Therefore, DHM may be a potentially therapeutic agent for IBD.

Genetic Diversity and Resistome Analysis of Campylobacter lari Isolated from Gulls in Croatia.

Campylobacter lari is a thermotolerant bacterium that sporadically causes gastrointestinal diseases in humans and can be found in wildlife and the environment. C. lari is an understudied species, especially in wild birds such as gulls. Gulls are potentially good carriers of pathogens due to their opportunistic behavior and tendency to gather in large flocks. During winter and their breeding period, 1753 gulls were captured, and cloacal swabs were taken to be tested for the presence of C. lari. From isolated bacteria, the DNA was sequenced, and sequence types (ST) were determined. Sixty-four swabs were positive for C. lari, and from those, forty-three different STs were determined, of which thirty-one were newly described. The whole genome was sequenced for 43 random isolates, and the same isolates were tested for antimicrobial susceptibility using the broth microdilution method to compare them to WGS-derived antimicrobial-resistant isolates. All the tested strains were susceptible to erythromycin, gentamicin, and chloramphenicol, and all were resistant to ciprofloxacin. Resistance to ciprofloxacin was attributed to a gyrA_2 T86V mutation. Genes connected to possible beta-lactam resistance (blaOXA genes) were also detected.