ABSTRACT
Diagnostic methods for Helicobacter pylori infection include, but are not limited to, urea breath test, serum antibody test, fecal antigen test, and rapid urease test. However, these methods suffer drawbacks such as low accuracy, high false-positive rate, complex operations, invasiveness, etc. Therefore, there is a need to develop simple, rapid, and noninvasive detection methods for H. pylori diagnosis. In this study, we propose a novel technique for accurately detecting H. pylori infection through machine learning analysis of surface-enhanced Raman scattering (SERS) spectra of gastric fluid samples that were noninvasively collected from human stomachs via the string test. One hundred participants were recruited to collect gastric fluid samples noninvasively. Therefore, 12,000 SERS spectra (n = 120 spectra/participant) were generated for building machine learning models evaluated by standard metrics in model performance assessment. According to the results, the Light Gradient Boosting Machine algorithm exhibited the best prediction capacity and time efficiency (accuracy = 99.54% and time = 2.61 seconds). Moreover, the Light Gradient Boosting Machine model was blindly tested on 2,000 SERS spectra collected from 100 participants with unknown H. pylori infection status, achieving a prediction accuracy of 82.15% compared with qPCR results. This novel technique is simple and rapid in diagnosing H. pylori infection, potentially complementing current H. pylori diagnostic methods.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Humans , Helicobacter Infections/diagnosis , Spectrum Analysis, Raman , Stomach , Urease/analysis , Sensitivity and SpecificityABSTRACT
Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of approximately half of the worldwide population, with higher prevalence in densely populated areas like Asia, the Caribbean, Latin America, and Africa. H. pylori infections range from asymptomatic cases to potentially fatal diseases, including peptic ulcers, chronic gastritis, and stomach adenocarcinoma. The management of these conditions has become more difficult due to the rising prevalence of drug-resistant H. pylori infections, which ultimately lead to gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. In 1994, the International Agency for Research on Cancer (IARC) categorized H. pylori as a Group I carcinogen, contributing to approximately 780,000 cancer cases annually. Antibiotic resistance against drugs used to treat H. pylori infections ranges between 15% and 50% worldwide, with Asian countries having exceptionally high rates. This review systematically examines the impacts of H. pylori infection, the increasing prevalence of antibiotic resistance, and the urgent need for accurate diagnosis and precision treatment. The present status of precision treatment strategies and prospective approaches for eradicating infections caused by antibiotic-resistant H. pylori will also be evaluated.
ABSTRACT
BACKGROUND AND AIM: Rates of antimicrobial-resistant Helicobacter pylori infection are rising globally, but little is known about contemporary resistance patterns, virulence factors, and phylogenetic patterns of isolates within Australia. We aimed to characterize antimicrobial resistance and genetic mutations associated with adverse clinical outcomes. METHODS: Whole genome sequencing, culturing, and antibiotic sensitivity data for refractory H. pylori isolates at Australian centers were collected between 2013 and 2022. Phylogenetic origins, antibiotic resistance mutations, and virulence factors were examined with phenotypic resistance profiles. RESULTS: One hundred thirty-five isolates underwent culture, with 109 of these undergoing whole genome sequencing. Forty-three isolates were isolated from patients in South Australia and 66 from Western Australia. Isolates originated primarily from hpEurope (59.6%), hpEastAsia (25.7%), and hpNEAfrica (6.4%). Antimicrobial resistance to clarithromycin was seen in 85% of isolates, metronidazole in 52%, levofloxacin in 18%, rifampicin in 14%, and amoxicillin in 9%. Most isolates (59%) were multi-drug resistant. Resistance concordance between genetically determined resistance and phenotypic resistance was 92% for clarithromycin and 94% for levofloxacin. Analysis of virulence factors demonstrated cag pathogenicity island (cagPAI) in 67% of isolates and cagA in 61%, correlating with isolate genetic origin. The most virulent s1m1 vacuolating cytotoxin A genotype was present in 26% of isolates. CONCLUSION: Refractory H. pylori isolates in Australia emanate from multiple global origins. Strong concordance between genetic and phenotypic antibiotic resistance profiles raises the possibility of utilizing genetic profiling in clinical practice. The dynamic landscape of H. pylori in Australia warrants the establishment of a national database to monitor H. pylori resistance and evolving virulence.
ABSTRACT
Populations of different South Asian nations including Bangladesh reportedly have a high risk of developing diabetes in recent years. This study aimed to investigate the differences in the gut microbiome of COVID-19-positive participants with or without type 2 diabetes mellitus (T2DM) compared with healthy control subjects. Microbiome data of 30 participants with T2DM were compared with 22 age-, sex-, and body mass index (BMI)-matched individuals. Clinical features were recorded while fecal samples were collected aseptically from the participants. Amplicon-based (16S rRNA) metagenome analyses were employed to explore the dysbiosis of gut microbiota and its correlation with genomic and functional features in COVID-19 patients with or without T2DM. Comparing the detected bacterial genera across the sample groups, 98 unique genera were identified, of which 9 genera had unique association with COVID-19 T2DM patients. Among different bacterial groups, Shigella (25%), Bacteroides (23.45%), and Megamonas (15.90%) had higher mean relative abundances in COVID-19 patients with T2DM. An elevated gut microbiota dysbiosis in T2DM patients with COVID-19 was observed while some metabolic functional changes correlated with bidirectional microbiome dysbiosis between diabetes and non-diabetes humans gut were also found. These results further highlight the possible association of COVID-19 infection that might be linked with alteration of gut microbiome among T2DM patients.
Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Humans , Gastrointestinal Microbiome/genetics , Diabetes Mellitus, Type 2/complications , Cross-Sectional Studies , RNA, Ribosomal, 16S/genetics , Dysbiosis/microbiology , Bangladesh/epidemiology , SARS-CoV-2/genetics , Bacteria/geneticsABSTRACT
BACKGROUND: The host-microbe interactions are complex, dynamic and context-dependent. In this regard, migratory fish species like hilsa shad (Tenualosa ilisha), which migrates from seawater to freshwater for spawning, provides a unique system for investigating the microbiome under an additional change in fish's habitat. This work was undertaken to detect taxonomic variation of microbiome and their function in the migration of hilsa. METHODS AND RESULTS: The study employed 16S rRNA amplicon-based metagenomic analysis to scrutinize bacterial diversity in hilsa gut, skin mucus and water. Thus, a total of 284 operational taxonomic units (OTUs), 9 phyla, 35 orders and 121 genera were identified in all samples. More than 60% of the identified bacteria were Proteobacteria with modest abundance (> 5%) of Firmicutes, Bacteroidetes and Actinobacteria. Leucobacter in gut and Serratia in skin mucus were the core bacterial genera, while Acinetobacter, Pseudomonas and Psychrobacter exhibited differential compositions in gut, skin mucus and water. CONCLUSIONS: Representative fresh-, brackish- and seawater samples of hilsa habitats were primarily composed of Vibrio, Serratia and Psychrobacter, and their diversity in seawater was significantly higher (P < 0.05) than freshwater. Overall, salinity and water microbiota had an influence on the microbial composition of hilsa shad, contributing to host metabolism and adaptation processes. This pioneer exploration of hilsa gut and skin mucus bacteria across habitats will advance our insights into microbiome assembly in migratory fish populations.
Subject(s)
Fishes , Microbiota , Animals , RNA, Ribosomal, 16S/genetics , Fishes/genetics , Fresh Water , Bacteria/genetics , Microbiota/genetics , WaterABSTRACT
Fifty percent of the world's population is infected with Helicobacter pylori, which can trigger many gastrointestinal disorders. H. pylori eradication therapy consists of two to three antimicrobial medicinal products, but they exhibit limited efficacy and may cause adverse side effects. Alternative therapies are urgent. It was assumed that an essential oil mixture, obtained from species from genera Satureja L., Origanum L. and Thymus L. and called the HerbELICO® essential oil mixture, could be useful in H. pylori infection treatment. HerbELICO® was analyzed by GC-MS and assessed in vitro against twenty H. pylori clinical strains isolated from patients of different geographical origins and with different antimicrobial medicinal products resistance profiles, and for its ability to penetrate the artificial mucin barrier. A customer case study included 15 users of HerbELICO®liquid/HerbELICO®solid dietary supplements (capsulated HerbELICO® mixture in liquid/solid form). Carvacrol and thymol were the most dominant compounds (47.44% and 11.62%, respectively), together with p-cymene (13.35%) and γ-terpinene (18.20%). The minimum concentration required to inhibit in vitro H. pylori growth by HerbELICO® was 4-5% (v/v); 10 min exposure to HerbELICO® was enough to kill off the examined H. pylori strains, while HerbELICO® was able to penetrate through mucin. A high eradication rate (up to 90%) and acceptance by consumers was observed.
Subject(s)
Anti-Infective Agents , Helicobacter pylori , Oils, Volatile , Origanum , Thymus Plant , Humans , Oils, Volatile/pharmacologyABSTRACT
BACKGROUND: Aeromonas veronii is a Gram-negative rod-shaped motile bacterium that inhabits mainly freshwater environments. A. veronii is a pathogen of aquatic animals, causing diseases in fish. A. veronii is also an emerging human enteric pathogen, causing mainly gastroenteritis with various severities and also often being detected in patients with inflammatory bowel disease. Currently, limited information is available on the genomic information of A. veronii strains that cause human gastrointestinal diseases. Here we sequenced, assembled and analysed 25 genomes (one complete genome and 24 draft genomes) of A. veronii strains isolated from patients with gastrointestinal diseases using combine sequencing technologies from Illumina and Oxford Nanopore. We also conducted comparative analysis of genomes of 168 global A. veronii strains isolated from different sources. RESULTS: We found that most of the A. veronii strains isolated from patients with gastrointestinal diseases were closely related to each other, and the remaining were closely related to strains from other sources. Nearly 300 putative virulence factors were identified. Aerolysin, microbial collagenase and multiple hemolysins were present in all strains isolated from patients with gastrointestinal diseases. Type III Secretory System (T3SS) in A. veronii was in AVI-1 genomic island identified in this study, most likely acquired via horizontal transfer from other Aeromonas species. T3SS was significantly less present in A. veronii strains isolated from patients with gastrointestinal diseases as compared to strains isolated from fish and domestic animals. CONCLUSIONS: This study provides novel information on source of infection and virulence of A. veronii in human gastrointestinal diseases.
Subject(s)
Aeromonas veronii , Gastrointestinal Diseases , Genome, Bacterial , Gram-Negative Bacterial Infections , Aeromonas veronii/genetics , Aeromonas veronii/pathogenicity , Animals , Fish Diseases/microbiology , Gastrointestinal Diseases/genetics , Gastrointestinal Diseases/microbiology , Gram-Negative Bacterial Infections/genetics , Humans , Virulence/geneticsABSTRACT
The present study aimed to characterize and compare the skin and gut microbial communities of rohu at various post-harvest stages of consumption using quantitative real-time polymerase chain reaction and 16S rRNA-based amplicon sequencing. Real-time PCR amplification detected higher copy numbers for coliform bacteria-Escherichia coli, Salmonella enterica and Shigella spp. in the marketed fish-compared to fresh and frozen samples. The 16S rRNA data revealed higher alpha diversity measurements in the skin of fish from different retail markets of Dhaka city. Beta ordination revealed distinct clustering of bacterial OTUs for the skin and gut samples from three different groups. At the phylum level, Proteobacteria was most abundant in all groups except the Fusobacteria in the control fish gut. Although Aeromonas was found ubiquitous in all types of samples, diverse bacterial genera were identified in the marketed fish samples. Nonetheless, low species richness was observed for the frozen fish. Most of the differentially abundant bacteria in the skin samples of marketed fish are opportunistic human pathogens enriched at different stages of postharvest handling and processing. Therefore, considering the microbial contamination in the aquatic environment in Bangladesh, post-harvest handling should be performed with proper methods and care to minimize bacterial transmission into fish.
Subject(s)
Cyprinidae , Microbiota , Animals , Bacteria/genetics , Bangladesh , Fresh Water , Humans , RNA, Ribosomal, 16S/geneticsABSTRACT
The lipopolysaccharide O-antigen structure expressed by the European Helicobacter pylori model strain G27 encompasses a trisaccharide, an intervening glucan-heptan and distal Lewis antigens that promote immune escape. However, several gaps still remain in the corresponding biosynthetic pathway. Here, systematic mutagenesis of glycosyltransferase genes in G27 combined with lipopolysaccharide structural analysis, uncovered HP0102 as the trisaccharide fucosyltransferase, HP1283 as the heptan transferase, and HP1578 as the GlcNAc transferase that initiates the synthesis of Lewis antigens onto the heptan motif. Comparative genomic analysis of G27 lipopolysaccharide biosynthetic genes in strains of different ethnic origin revealed that East-Asian strains lack the HP1283/HP1578 genes but contain an additional copy of HP1105 and JHP0562. Further correlation of different lipopolysaccharide structures with corresponding gene contents led us to propose that the second copy of HP1105 and the JHP0562 may function as the GlcNAc and Gal transferase, respectively, to initiate synthesis of the Lewis antigen onto the Glc-Trio-Core in East-Asian strains lacking the HP1283/HP1578 genes. In view of the high gastric cancer rate in East Asia, the absence of the HP1283/HP1578 genes in East-Asian H. pylori strains warrants future studies addressing the role of the lipopolysaccharide heptan in pathogenesis.
Subject(s)
Helicobacter Infections/genetics , Lipopolysaccharides/genetics , O Antigens/genetics , Stomach Neoplasms/genetics , Asian People , Fucosyltransferases/genetics , Fucosyltransferases/immunology , Glucans/genetics , Glycosyltransferases/genetics , Glycosyltransferases/immunology , Helicobacter Infections/immunology , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Helicobacter pylori/genetics , Helicobacter pylori/immunology , Helicobacter pylori/pathogenicity , Humans , Lewis Blood Group Antigens/genetics , Lewis Blood Group Antigens/immunology , Lipopolysaccharides/chemistry , Lipopolysaccharides/immunology , Mutagenesis , O Antigens/immunology , Stomach Neoplasms/epidemiology , Stomach Neoplasms/immunology , Stomach Neoplasms/pathologyABSTRACT
Probiotic supplements are being used to improve the growth and immune performance of aquaculture species over the last couple of decades. In recent times, black soldier fly (BSF) is considered as one of the promising sources of alternative protein to fishmeal protein in aqua-diets. Since the freshwater crayfish, marron (Cherax cainii), a Western Australian's native and iconic freshwater crayfish species, grows fairly slow under commercial farming environment, this study was aimed to investigate the supplemental effect of BSF and BSF with probiotic bacteria Lactobacillus plantarum (BSFLP) on overall health and immune performance of marron after 56 days of feeding under laboratory conditions. The post-trial data revealed insignificant influences of any diets on growth performance, however, both BSF and BSFLP based diets significantly improved some haemolymph parameters and gut health of marron. High throughput sequence data revealed that both BSF and BSFLP diets significantly improved the diversity of microbial communities including some beneficial bacteria for crustaceans in the hindgut of marron. Further analysis showed that both BSF and BSFLP diets upregulated the expression of some genes in the gut tissue and haemocytes associated with the innate immune response of marron at 48 h post injection. The up-regulation of some immune genes in BSFLP diet group was found significantly linked to OTU abundance for Lactobacillus. The findings of this study could be helpful for improving overall health status of marron.
Subject(s)
Astacoidea/immunology , Immunity, Innate , Lactobacillus plantarum/chemistry , Probiotics/metabolism , Animal Feed/analysis , Animals , Diet/veterinary , Dietary Supplements/analysis , Diptera/chemistry , Diptera/growth & development , Diptera/microbiology , Dose-Response Relationship, Drug , Gastrointestinal Tract/physiology , Larva/chemistry , Larva/growth & development , Larva/microbiology , Probiotics/administration & dosage , Random AllocationABSTRACT
Vibriosis caused by luminous Vibrio species is one of the biggest challenges to shrimp industry in Bangladesh. This study aimed to characterize whole microbial communities from Vibrio-infected black tiger shrimp (Penaeus monodon) using 16S rRNA-based amplicon sequencing. A total of 36 disease-free and infected shrimp were collected from six different hatcheries in Bagerhat, Bangladesh. A final pool of 12 samples (n = 6) was created by homogenization of the hepatopancreas samples from three shrimps collected from each hatchery for the same group. The amplicon sequencing data revealed significant (p < .05) decrease of alpha diversity measurements and subsequent effects (p < .05) on the hepatopancreas microbiota in the infected group, compared to control shrimp. Proteobateria and Aeromonas were the most dominant bacteria at phylum and genus level in both groups and identified as core microbiota in the community. Two bacterial groups at phyla level and eight at genus level were found associated with the alteration of hepatopancreas microbial communities and associated gene functions in vibriosis-infected shrimp, revealed by differential abundance and KEGG pathway analysis. The overwhelming abundance of Citroibacter, Shewanella and Candidatus lineages in vibriosis-infected shrimp needs further investigations.
Subject(s)
Genes, Bacterial , Penaeidae/microbiology , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Vibrio/genetics , Animals , RNA, Bacterial/metabolism , RNA, Ribosomal, 16S/metabolism , Sequence Analysis, RNA , Vibrio/metabolismABSTRACT
Helicobacter pylori infection causes chronic active gastritis that after many years of infection can develop into peptic ulceration or gastric adenocarcinoma. The bacterium is highly adapted to surviving in the gastric environment and a key adaptation is the virulence factor urease. Although widely postulated, the requirement of urease expression for persistent infection has not been elucidated experimentally as conventional urease knockout mutants are incapable of colonization. To overcome this constraint, conditional H. pylori urease mutants were constructed by adapting the tetracycline inducible expression system that enabled changing the urease phenotype of the bacteria during established infection. Through tight regulation we demonstrate that urease expression is not only required for establishing initial colonization but also for maintaining chronic infection. Furthermore, successful isolation of tet-escape mutants from a late infection time point revealed the strong selective pressure on this gastric pathogen to continuously express urease in order to maintain chronic infection. In addition to mutations in the conditional gene expression system, escape mutants were found to harbor changes in other genes including the alternative RNA polymerase sigma factor, fliA, highlighting the genetic plasticity of H. pylori to adapt to a changing niche. The tet-system described here opens up opportunities to studying genes involved in the chronic stage of H. pylori infection to gain insight into bacterial mechanisms promoting immune escape and life-long infection. Furthermore, this genetic tool also allows for a new avenue of inquiry into understanding the importance of various virulence determinants in a changing biological environment when the bacterium is put under duress.
Subject(s)
Gastritis/genetics , Gene Silencing/physiology , Helicobacter Infections/immunology , Helicobacter pylori/genetics , Urease/metabolism , Animals , Bacterial Proteins/metabolism , Chronic Disease , Gastric Mucosa/microbiology , Gastritis/microbiology , Gene Expression/genetics , Mice , Stomach Neoplasms/geneticsABSTRACT
BACKGROUND: Helicobacter pylori, gastric cancer-causing bacteria, survive in their gastric environment of more than 50% of the world population. The presence of H. pylori in the gastric vicinity promotes the development of various diseases including peptic ulcer and gastric carcinoma. H. pylori produce and secret Vacuolating cytotoxin A (VacA), a major toxin facilitating the bacteria against the host defense system. The toxin causes multiple effects in epithelial cells and immune cells, especially T cells, B cells, and Macrophages. METHODS: This review describes the diverse functionalities of protein toxin VacA. The specific objective of this review is to address the overall structure, mechanism, and functions of VacA in various cell types. The recent advancements are summarized and discussed and thus conclusion is drawn based on the overall reported evidences. RESULTS: The searched articles on H. pylori VacA were evaluated and limited up to 66 articles for this review. The articles were divided into four major categories including articles on vacA gene, VacA toxin, distinct effects of VacA toxin, and their effects on various cells. Based on these studies, the review article was prepared. CONCLUSIONS: This review describes an overview of how VacA is secreted by H. pylori and contributes to colonization and virulence in multiple ways by affecting epithelial cells, T cells, Dendritic cells, B cells, and Macrophages. The reported evidence suggests that the comprehensive outlook need to be developed for understanding distinctive functionalities of VacA.
Subject(s)
Bacterial Proteins/metabolism , Bacterial Toxins/metabolism , Cytotoxins/metabolism , Helicobacter pylori/chemistry , Helicobacter pylori/pathogenicity , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Toxins/chemistry , Bacterial Toxins/genetics , Cytotoxins/chemistry , Cytotoxins/genetics , Epithelial Cells , Helicobacter pylori/growth & development , Humans , Lymphocytes , Macrophages , Vacuoles/metabolism , VirulenceABSTRACT
BACKGROUND: Helicobacter suis is a very fastidious microorganism associated with gastritis, gastric ulcers, and mucosa-associated lymphoid tissue lymphoma in humans. In vitro isolation of this agent from human patients has so far been unsuccessful. MATERIALS AND METHODS: A probe-based real-time PCR (RT-PCR) for the rapid detection of H. suis in gastric biopsies was developed. Secondly, a mouse-passage-based protocol was optimized for isolation of low numbers of viable H. suis bacteria. Mice were inoculated with different numbers of viable H. suis (102 -108 ) and kept for 4 weeks to allow multiplication of this pathogen. RESULTS: The probe-based real-time PCR (RT-PCR) exhibited a high degree of diagnostic specificity and analytical sensitivity, high linear correlations (r2 between 0.995 and 0.999), and high amplification efficiencies (>90%) for H. suis. No cross-reactivity was detected with human, porcine, non-human primate, and murine DNA nor with DNA from other bacteria including Helicobacter spp. and Campylobacter spp. H. suis was successfully re-isolated from the stomach of mice inoculated with at least 104 viable H. suis, using a biphasic medium (pH 5), consisting of Brucella agar with Brucella broth on top, both supplemented with vitox supplement, Campylobacter-selective supplement, amphotericin (5 µg/mL), HCl (0.05%), fetal bovine serum (20%), and linezolid (5 µg/mL). Linezolid was necessary to inhibit proliferation of contaminants, including lactobacilli. CONCLUSION: The methods described above can be implemented for detection or isolation of H. suis from human gastric biopsies.
Subject(s)
Helicobacter Infections/diagnosis , Helicobacter heilmannii/isolation & purification , Molecular Diagnostic Techniques/methods , Real-Time Polymerase Chain Reaction/methods , Stomach Diseases/diagnosis , Animals , Biopsy , Disease Models, Animal , Female , Helicobacter Infections/microbiology , Helicobacter heilmannii/genetics , Mice, Inbred C57BL , Primates , Sensitivity and Specificity , Stomach Diseases/microbiologyABSTRACT
Helicobacter heilmannii naturally colonizes the stomachs of dogs and cats and has been associated with gastric disorders in humans. Nine feline Helicobacter strains, classified as H. heilmannii based on ureAB and 16S rRNA gene sequences, were divided into a highly virulent and a low-virulence group. The genomes of these strains were sequenced to investigate their phylogenetic relationships, to define their gene content and diversity, and to determine if the differences in pathogenicity were associated with the presence or absence of potential virulence genes. The capacities of these helicobacters to bind to the gastric mucosa were investigated as well. Our analyses revealed that the low-virulence strains do not belong to the species H. heilmannii but to a novel, closely related species for which we propose the name Helicobacter ailurogastricus. Several homologs of H. pylori virulence factors, such as IceA1, HrgA, and jhp0562-like glycosyltransferase, are present in H. heilmannii but absent in H. ailurogastricus. Both species contain a VacA-like autotransporter, for which the passenger domain is remarkably larger in H. ailurogastricus than in H. heilmannii. In addition, H. ailurogastricus shows clear differences in binding to the gastric mucosa compared to H. heilmannii. These findings highlight the low-virulence character of this novel Helicobacter species.
Subject(s)
Gastric Mucosa/microbiology , Gastritis/microbiology , Helicobacter heilmannii/genetics , Helicobacter heilmannii/pathogenicity , Intestinal Mucosa/microbiology , Animals , Bacterial Adhesion/genetics , Bacterial Proteins/genetics , Cats , Cell Line , Deoxyribonucleases, Type II Site-Specific/genetics , Dogs , Epithelial Cells/microbiology , Gastric Mucosa/cytology , Gerbillinae , Glycosyltransferases/genetics , Helicobacter Infections/microbiology , Helicobacter heilmannii/classification , Humans , Intestinal Mucosa/cytology , Molecular Sequence Data , Phylogeny , Protein Structure, Tertiary , RNA, Ribosomal, 16S/genetics , Virulence/genetics , Zoonoses/microbiologyABSTRACT
Carbon sources are considered as critical input for the health and immunity of aquatic animals. The present study investigated the impact of different carbon sources on water quality parameters, carbon to nitrogen (C/N) ratio and microbial community in sediments, and health responses of marron (Cherax cainii) under laboratory conditions. Following one week of acclimation, 120 marron were randomly assigned to 12 experimental tanks. There were four treatments including one untreated control and three groups with carbon addition to maintain a C/N ratio of 12 maintained in culture water. Carbon supplementation groups included corn flour (CBC12), molasses (MBC12) and wheat flour (WBC12). At the end of the 60-day trial, MBC12 resulted in the highest sediment C/N ratio, followed by CBC12. Weight gain and specific growth rate were higher in MBC12, compared to control. The protease activity in marron hepatopancreas, total haemocyte count and lysozyme activity in haemolymph were highest in MBC12. Analysis of 16S rRNA sequence data of tank sediments revealed increased bacterial alpha diversity in MBC12 and WBC12. Proteobacteria was the most abundant phylum in MBC12 (88.6%), followed by control (82.4%) and CBC12 (72.8%). Sphingobium and Novosphingobium were the most abundant genera in control and MBC12 groups, respectively. Higher Aeromonas abundance in CBC12 and Flavobacterium in WBC12 were observed. Overall results indicated that MBC12 led to improved water quality, retaining high C/N ratio and enriched the bacterial populations in sediments resulting in improved growth and immune performance of marron.
Subject(s)
Astacoidea , Flour , Animals , Astacoidea/physiology , RNA, Ribosomal, 16S/genetics , Triticum , Bacteria/genetics , Geologic Sediments , Carbon/pharmacologyABSTRACT
Aeromonas caviae is an emerging human enteric pathogen. However, the genomic features and virulence genes of A. caviae strains from human gastroenteritis and other sources have not been fully elucidated. Here, we conducted a genomic analysis of 565 global A. caviae strains isolated from different sources, including 261 strains isolated from faecal samples of gastroenteritis patients, of which 18 genomes were sequenced in this study. The presence of bacterial virulence genes and secretion systems in A. caviae strains from different sources was compared, and the phylogenetic relationship of A. caviae strains was assessed based on the core genome. The complete genome of A. caviae strain A20-9 isolated from a gastroenteritis patient was obtained in this study, from which 300 putative virulence factors and a T4SS-encoding plasmid, pAC, were identified. Genes encoding T4SS were also identified in a novel genomic island, ACI-1, from other T4SS-positive strains. The prevalence of T4SS was significantly lower in A. caviae strains from gastroenteritis patients than in environmental strains (3â%, P<0.0001 vs 14â%, P<0.01). Conversely, the prevalence of T6SS was significantly higher in A. caviae strains isolated from gastroenteritis patients than in environmental strains (25â%, P<0.05 vs 13ââ%, P<0.01). Four phylogenetic clusters were formed based on the core genome of 565 A. caviae strains, and strains carrying T6SS often showed close phylogenetic relationships. T3SS, aerolysin and thermostable cytotonic enterotoxin were absent in all 565 A. caviae strains. Our findings provide novel information on the genomic features of A. caviae and suggest that T6SS may play a role in A. caviae-induced human gastroenteritis.
Subject(s)
Aeromonas caviae , Gastroenteritis , Genome, Bacterial , Phylogeny , Virulence Factors , Gastroenteritis/microbiology , Humans , Aeromonas caviae/genetics , Aeromonas caviae/classification , Virulence Factors/genetics , Type VI Secretion Systems/genetics , Feces/microbiology , Gram-Negative Bacterial Infections/microbiology , Genomic Islands , Plasmids/geneticsABSTRACT
INTRODUCTION: Helicobacter pylori (H. pylori) infection has been associated with gastric carcinogenesis. However, the precise involvement of LRP8, the low-density lipoprotein receptor-related protein 8, in H. pylori pathogenesis and gastric cancer (GC) remains poorly understood. OBJECTIVES: To investigate the potential role of LRP8 in H. pylori infection and gastric carcinogenesis. METHODS: Three-dimensional human-derived gastric organoids (hGO) and gastric cancer organoids (hGCO) were synthesized from the tissues obtained from human donors. In this work, multi-omics combined with in vivo and in vitro studies were conducted to investigate the potential involvement of LRP8 in H. pylori-induced GC. RESULTS: We found that H. pylori infection significantly upregulated the expression of LRP8 in human GC tissues, cells, organoids, and mouse gastric mucous. In particular, LRP8 exhibited a distinct enrichment in cancer stem cells (CSC). Functionally, silencing of LRP8 affected the formation and proliferation of tumor spheroids, while increased expression of LRP8 was associated with increased proliferation and stemness of GC cells and organoids. Mechanistically, LRP8 promotes the binding of E-cadherin to ß-catenin, thereby promoting nuclear translocation and transcriptional activity of ß-catenin. Furthermore, LRP8 interacts with the cytotoxin-associated gene A (CagA) to form the CagA/LRP8/ß-catenin complex. This complex further amplifies H. pylori-induced ß-catenin nuclear translocation, leading to increased transcription of inflammatory factors and CSC markers. Clinical analysis demonstrated that abnormal overexpression of LRP8 is correlated with a poor prognosis and resistance to 5-Fluorouracil in patients with GC. CONCLUSION: Our findings provide valuable information on the molecular intricacies of H. pylori-induced gastric carcinogenesis, offering potential therapeutic targets and prognostic markers for GC.
ABSTRACT
Bacterial antimicrobial resistance (AMR) has emerged as a significant concern worldwide. The microbial community profile and potential AMR level in aquaculture ponds are often undervalued and attract less attention than other aquatic environments. We used amplicon and metagenomic shotgun sequencing to study microbial communities and AMR in six freshwater polyculture ponds in rural and urban areas of Bangladesh. Amplicon sequencing revealed different community structures between rural and urban ponds, with urban ponds having a higher bacterial diversity and opportunistic pathogens including Streptococcus, Staphylococcus, and Corynebacterium. Despite proteobacterial dominance, Firmicutes was the most interactive in the community network, especially in the urban ponds. Metagenomes showed that drug resistance was the most common type of AMR found, while metal resistance was only observed in urban ponds. AMR and metal resistance genes were found mainly in beta and gamma-proteobacteria in urban ponds, while AMR was found primarily in alpha-proteobacteria in rural ponds. We identified potential pathogens with a high profile of AMR and metal resistance in urban aquaculture ponds. As these ponds provide a significant source of protein for humans, our results raise significant concerns for the environmental sustainability of this food source and the dissemination of AMR into the food chain.
Subject(s)
Aquaculture , Bacteria , Drug Resistance, Bacterial , Ponds , Ponds/microbiology , Bacteria/drug effects , Bacteria/genetics , Bangladesh , Anti-Bacterial Agents/pharmacology , Cities , Water Microbiology , Microbiota/drug effectsABSTRACT
OBJECTIVE: The high incidence of endodontic failure is associated with the remnants of Enterococcus faecalis present within the intricate anatomies of the root canal system (RCS), often inaccessible by the current endodontic practices. This study was aimed at evaluating the effect of high-intensity focused ultrasound (HIFU) and photodynamic therapy (PDT) on E. faecalis biofilms in artificially infected root canals for the potential application in current endodontic practices. METHODS: Forty-five single-rooted extracted teeth were instrumented using hand files, sterilized in an autoclave, infected with E. faecalis and incubated for 4 wk. The specimens were treated and identified as follows: Control, 4% sodium hypochlorite (NaOCl); riboflavin (1 mg/mL); light only; HIFU (250 kHz, 20 W, 60s); PDT; riboflavin/HIFU; light/HIFU; and riboflavin/HIFU/light. Bactericidal efficacy was determined by colony-forming units (CFU), (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). RESULTS: Enterococcus faecalis biofilm exhibited significantly lower metabolic activity when treated with HIFU (250 kHz, 20 W, 60 s) compared with the control (4% NaOCl) and PDT groups. A similar phenomenon was observed with the CFU assay. HIFU remained the most effective treatment modality, with consistent results in CLSM and SEM. CONCLUSION: This study highlighted the potential application of HIFU as an adjunct drug-free, non-destructive root canal disinfection method for endodontic treatment, suggesting an alternative to the current gold standard of 4% NaOCl and PDT.