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Asian Journal of Surgery Apr 2024
PubMed: 38658273
DOI: 10.1016/j.asjsur.2024.04.072 -
IScience May 2024is an emerging foodborne pathogen that produces VFH ( hemolysin) and δVFH (delta- hemolysin). The function of δVFH is unclear. Currently, no pathogenic . from deep...
is an emerging foodborne pathogen that produces VFH ( hemolysin) and δVFH (delta- hemolysin). The function of δVFH is unclear. Currently, no pathogenic . from deep sea has been reported. In this work, a deep-sea . isolate (V13) was examined for pathogenicity. V13 was most closely related to ATCC 33809, a human isolate, but possessed 262 unique genes. V13 caused lethal infection in fish and induced pyroptosis involving activation of the NLRP3 inflammasome, caspase 1 (Casp1), and gasdermin D (GSDMD). V13 defective in VFH or VFH plus δVFH exhibited significantly weakened cytotoxicity. Recombinant δVFH induced NLRP3-Casp1-GSDMD-mediated pyroptosis in a manner that depended on K efflux and intracellular Ca accumulation. δVFH bound several plasma membrane lipids, and these bindings were crucial for δVFH cytotoxicity. Together these results provided new insights into the function of δVFH and the virulence mechanism of .
PubMed: 38650982
DOI: 10.1016/j.isci.2024.109558 -
Frontiers in Immunology 2024The culture of Pacific oysters () is of significant socio-economic importance in the U.S. Pacific Northwest and other temperate regions worldwide, with disease outbreaks...
INTRODUCTION
The culture of Pacific oysters () is of significant socio-economic importance in the U.S. Pacific Northwest and other temperate regions worldwide, with disease outbreaks acting as significant bottlenecks to the successful production of healthy seed larvae. Therefore, the current study aims to describe the mechanisms of a probiotic combination in improving the survival of larvae. Specifically, we investigate changes in larval gene expression in response to infection with or without a pre-treatment of a novel probiotic combination.
METHODS
Treatment groups consisted of replicates of Pacific oyster larvae exposed to a) a combination of four probiotic bacteria at a total concentration of 3.0 x 10 CFU/mL at 18 hours post-fertilization (hpf), b) pathogenic RE22 at a concentration of 6.0 x 10 CFU/mL at 48 hpf, and c) the probiotic combination at 18 hpf and RE22 at 48 hpf. RNA was extracted from washed larvae after 72 hpf, and transcriptome sequencing was used to identify significant differentially expressed genes (DEGs) within each treatment.
RESULTS
Larvae challenged with showed enhanced expression of genes responsible for inhibiting immune signaling (i.e., , ) and inducing apoptosis (i.e., ). However, when pre-treated with the probiotic combination, these genes were no longer differentially expressed relative to untreated control larvae. Additionally, pre-treatment with the probiotic combination increased expression of immune signaling proteins and immune effectors (i.e., , ). Apparent immunomodulation in response to probiotic treatment corresponds to an increase in the survival of larvae infected with by up to 82%.
DISCUSSION
These results indicate that infection with can suppress the larval immune response while also prompting cell death. Furthermore, the results suggest that the probiotic combination treatment negates the deleterious effects of on larval gene expression while stimulating the expression of genes involved in infection defense mechanisms.
Topics: Animals; Probiotics; Larva; Crassostrea; Vibrio; Vibrio Infections; Transcriptome; Immunomodulation
PubMed: 38650950
DOI: 10.3389/fimmu.2024.1380089 -
Scientific Reports Apr 2024Food-related illnesses have become a growing public concern due to their considerable socioeconomic and medical impacts. Vibrio parahaemolyticus and Staphylococcus...
Food-related illnesses have become a growing public concern due to their considerable socioeconomic and medical impacts. Vibrio parahaemolyticus and Staphylococcus aureus have been implicated as causative organisms of food-related infections and poisoning, and both can form biofilms which confer antibiotic resistance. Hence, the need for continuous search for compounds with antibiofilm and antivirulence properties. In this study, 22 iodinated hydrocarbons were screened for their antibiofilm activity, and of these, iodopropynyl butylcarbamate (IPBC) was found to effectively control biofilm formation of both pathogens with a MIC of 50 µg/mL which was bactericidal to V. parahaemolyticus and S. aureus. Microscopic studies confirmed IPBC inhibits biofilm formation of both bacteria and also disrupted their mixed biofilm formation. Furthermore, IPBC suppressed virulence activities such as motility and hemolytic activity of V. parahaemolyticus and the cell surface hydrophobicity of S. aureus. It exhibited a preservative potential against both pathogens in a shrimp model. IPBC disrupted the cell membrane of S. aureus and V. parahaemolyticus and differentially affected gene expressions related to biofilm formation and virulence. Additionally, it displayed broad-spectrum antibiofilm activities against other clinically relevant pathogens. These findings indicate IPBC offers a potential means of controlling infections mediated by Vibrio and Staphylococcus biofilms.
Topics: Biofilms; Vibrio parahaemolyticus; Staphylococcus aureus; Anti-Bacterial Agents; Microbial Sensitivity Tests; Animals; Virulence
PubMed: 38644387
DOI: 10.1038/s41598-024-55479-7 -
BMC Infectious Diseases Apr 2024Vibrio furnissii is an emerging human pathogen closely related to V. fluvialis that causes acute gastroenteritis. V. furnissii infection has been reported to be rarer...
BACKGROUND
Vibrio furnissii is an emerging human pathogen closely related to V. fluvialis that causes acute gastroenteritis. V. furnissii infection has been reported to be rarer than V. fluvialis, but a multi-drug resistance plasmid has recently been discovered in V. furnissii.
METHODS
During daily monitoring at a general hospital in Beijing, China, seven V. furnissii strains were collected from patients aged over 14 years who presented with acute diarrhoea between April and October 2018. Genome analysis and comparison were performed for virulence and antimicrobial resistance genes, plasmids and transposon islands, together with phylogenetic analysis. Antimicrobial resistance to 19 antibiotics was investigated using the microbroth dilution method. Virulence phenotypes were investigated based on type VI secretion system (T6SS) expression and using a bacterial killing assay and a haemolysin assay.
RESULTS
Phylogenetic analysis based on single-nucleotide polymorphisms revealed a closer relationship between V. furnissii and V. fluvialis than between other Vibrio spp. The seven V. furnissii isolates were in different monophyletic clades in the phylogenetic tree, suggesting that the seven cases of gastroenteritis were independent. High resistance to cefazolin, tetracycline and streptomycin was found in the V. furnissii isolates at respective rates of 100.0%, 57.1% and 42.9%, and intermediate resistance to ampicillin/sulbactam and imipenem was observed at respective rates of 85.7% and 85.7%. Of the tested strains, VFBJ02 was resistant to both imipenem and meropenem, while VFBJ01, VFBJ02, VFBJ05 and VFBJ07 were multi-drug resistant. Transposon islands containing antibiotic resistance genes were found on the multi-drug resistance plasmid in VFBJ05. Such transposon islands also occurred in VFBJ07 but were located on the chromosome. The virulence-related genes T6SS, vfh, hupO, vfp and ilpA were widespread in V. furnissii. The results of the virulence phenotype assays demonstrated that our isolated V. furnissii strains encoded an activated T6SS and grew in large colonies with strong beta-haemolysis on blood agar.
CONCLUSION
This study showed that diarrhoea associated with V. furnissii occurred sporadically and was more common than expected in the summer in Beijing, China. The antibiotic resistance of V. furnissii has unique characteristics compared with that of V. fluvialis. Fluoroquinolones and third-generation cephalosporins, such as ceftazidime and doxycycline, were effective at treating V. furnissii infection. Continua laboratory-based surveillance is needed for the prevention and control of V. furnissii infection, especially the dissemination of the antibiotic resistance genes in this pathogen.
Topics: Humans; Aged; Virulence; Phylogeny; Vibrio; Anti-Bacterial Agents; Drug Resistance, Microbial; Diarrhea; Gastroenteritis; Imipenem
PubMed: 38641583
DOI: 10.1186/s12879-024-09273-5 -
Frontiers in Cellular and Infection... 2024To evaluate the antibacterial effect of Tanreqing (TRQ) against and its inhibition activity on bacterial biofilm formation and , and to explore the mechanism of the...
OBJECTIVE
To evaluate the antibacterial effect of Tanreqing (TRQ) against and its inhibition activity on bacterial biofilm formation and , and to explore the mechanism of the inhibitory effects of TRQ on biofilm formation.
METHODS
An biofilm model of was established, and the impact of TRQ on biofilm formation was evaluated using crystal violet staining and scanning electron microscopy (SEM). Furthermore, the clearance effect of TRQ against in the biofilm was assessed using the viable plate counting method; q-RT PCR as used to evaluate the inhibitory effect of different concentrations of TRQ on the expression of biofilm-related genes in ; The activity of quorum sensing signal molecule AI-2 was detected by bioluminescence assay; Meanwhile, a guinea pig lung infection model of was constructed, and after treated with drugs, pathological analysis of lung tissue and determination of bacterial load in lung tissue were performed. The treatment groups included TRQ group, imipenem(IPM) group, TRQ+IPM group, and sterile saline group as the control.
RESULTS
The formation of biofilm was significantly inhibited by TRQ experiments. Furthermore, when combined with IPM, the clearance of in the biofilm was notably increased compared to the TRQ group and IPM group alone. q-RT PCR analysis revealed that TRQ down-regulated the expression of genes related to biofilm formation in , specifically , , , and , and also inhibited the activity of AI-2 molecules in the bacterium. experiments demonstrated that TRQ effectively treated guinea pig lung infections, resulting in reduced lung inflammation. Additionally, when combined with IPM, there was a significant reduction in the bacterial load in lung tissue.
CONCLUSION
TRQ as a potential therapeutic agent plays a great role in the treatment of infections, particularly in combination with conventional antibiotics. And TRQ can enhanced the clearance effect on the bacterium by inhibiting the biofilm formation, which provided experimental evidence in support of clinical treatment of TRQ against infections.
Topics: Animals; Guinea Pigs; Klebsiella pneumoniae; Quorum Sensing; Biofilms; Anti-Bacterial Agents; Pneumonia; Klebsiella Infections; Drugs, Chinese Herbal
PubMed: 38638833
DOI: 10.3389/fcimb.2024.1368450 -
Open Veterinary Journal Jan 2024The high summer mortality in many fish farms, which had detrimental economic and social implications, was a serious challenge that the fish industry had to deal with.
BACKGROUND
The high summer mortality in many fish farms, which had detrimental economic and social implications, was a serious challenge that the fish industry had to deal with.
AIM
With an examination of the most effective antibiotic, the ongoing research was intended to shed light on the identification of the main bacterial pathogens associated with the summer mortality syndrome in the diseased farmed Nile tilapia.
METHODS
Six hundred dead Nile tilapia samples that had suffered from summer mortality were collected from several fish farms between May and October of 2022. The gathered fish displayed hemorrhagic areas on the skin, scale detachment, fin degeneration, erosions, skin ulcers, and corneal opacity with unilateral and/or bilateral exophthalmia. The most prominent internal appearance was swelling of the internal organs with sanguineous ascetic fluid.
RESULTS
There were 225 bacterial isolates found. Six species were identified through phenotypic and biochemical analysis; they were , o, , , , and spp., in descending percentage, respectively. spp., spp., and spp. were the three most frequent isolated bacterial pathogens. The identification of , spp., and , the three most common bacterial isolates, was confirmed by molecular analysis by polymerase chain reaction. Most of the tested strains were found to be responsive to Ciprofloxacin (CIP), Gentamicin (CN), and Chloramphenicol (C) but resistant to Amoxicillin (AMX), according to an antibiotic sensitivity test.
CONCLUSION
The three most dangerous common bacterial infections discovered during mass-farmed tilapia summer mortality are , sp., and . This makes it clear that high water temperatures may raise the possibility of bacterial infections, which could cause widespread tilapia mortality and substantial financial losses. Therefore, it is crucial to maintain a beneficial fish culture, environment, and husbandry practices to enhance the tilapia-rearing environment and lessen the virulence of the disease. Isolated bacterial strains showed low levels of resistance to AMX but were vulnerable to CIP, CN, and C.
Topics: Animals; Cichlids; Streptococcus; Anti-Bacterial Agents; Virulence; Bacterial Infections
PubMed: 38633195
DOI: 10.5455/OVJ.2024.v14.i1.7 -
Archives of Iranian Medicine Feb 2024It is important to honor the contributions of scientific leaders who have dedicated their lives to advancing knowledge and serving their country. One way is to document...
It is important to honor the contributions of scientific leaders who have dedicated their lives to advancing knowledge and serving their country. One way is to document their experiences and personalities in a documentary format, which can serve as a historical record and an inspiration for future generations. Dr. Mostafa Pourtaghva Shahrestani, a renowned physician and specialist in infectious diseases and tropical medicine, has made significant contributions to public health in Iran. He has played a crucial role in controlling infectious diseases such as smallpox, tuberculosis, rabies, plague, and cholera. Throughout his career, he has held various executive positions, including the head of Pasteur Hospital and the director of the Pasteur Institute of Iran. Dr. Pourtaghva's life is a testament to his unwavering dedication to public health services, as evidenced by his continuous effort, love, and interest in honest work. His inspiring story can serve as a model for those who seek to follow in his footsteps.
Topics: Male; Humans; Academies and Institutes; Cholera; Hospitals; Iran; Knowledge
PubMed: 38619034
DOI: 10.34172/aim.2024.16 -
BioRxiv : the Preprint Server For... Apr 2024A major challenge faced by is constant predation by bacteriophage (phage) in aquatic reservoirs and during infection of human hosts. To overcome phage predation, has...
A major challenge faced by is constant predation by bacteriophage (phage) in aquatic reservoirs and during infection of human hosts. To overcome phage predation, has evolved a myriad of phage defense systems. Although several novel defense systems have been discovered, we hypothesized more were encoded in given the relative paucity of phage that have been isolated which infect this species. Using a genomic library, we identified a Type IV restriction system consisting of two genes within a 16kB region of the pathogenicity island-2 that we name TgvA and TgvB (ype I-embedded mrSD-like system of PI-2). We show that both TgvA and TgvB are required for defense against T2, T4, and T6 by targeting glucosylated 5-hydroxymethylcytosine (5hmC). T2 or T4 phages that lose the glucose modification are resistant to TgvAB defense but exhibit a significant evolutionary tradeoff becoming susceptible to other Type IV restriction systems that target unglucosylated 5hmC. We show that additional phage defense genes are encoded in VPI-2 that protect against other phage like T3, secΦ18, secΦ27 and λ. Our study uncovers a novel Type IV restriction system in , increasing our understanding of the evolution and ecology of while highlighting the evolutionary interplay between restriction systems and phage genome modification.
PubMed: 38617239
DOI: 10.1101/2024.04.05.588314 -
The Lancet. Global Health May 2024In October, 2017, WHO launched a strategy to eliminate cholera by 2030. A primary challenge in meeting this goal is the limited global supply capacity of oral cholera... (Randomized Controlled Trial)
Randomized Controlled Trial
Safety and immunogenicity of the Euvichol-S oral cholera vaccine for prevention of Vibrio cholerae O1 infection in Nepal: an observer-blind, active-controlled, randomised, non-inferiority, phase 3 trial.
BACKGROUND
In October, 2017, WHO launched a strategy to eliminate cholera by 2030. A primary challenge in meeting this goal is the limited global supply capacity of oral cholera vaccine and the worsening of cholera outbreaks since 2021. To help address the current shortage of oral cholera vaccine, a WHO prequalified oral cholera vaccine, Euvichol-Plus was reformulated by reducing the number of components and inactivation methods. We aimed to evaluate the immunogenicity and safety of Euvichol-S (EuBiologics, Seoul, South Korea) compared with an active control vaccine, Shanchol (Sanofi Healthcare India, Telangana, India) in participants of various ages in Nepal.
METHODS
We did an observer-blind, active-controlled, randomised, non-inferiority, phase 3 trial at four hospitals in Nepal. Eligible participants were healthy individuals aged 1-40 years without a history of cholera vaccination. Individuals with a history of hypersensitivity reactions to other preventive vaccines, severe chronic disease, previous cholera vaccination, receipt of blood or blood-derived products in the past 3 months or other vaccine within 4 weeks before enrolment, and pregnant or lactating women were excluded. Participants were randomly assigned (1:1:1:1) by block randomisation (block sizes of two, four, six, or eight) to one of four groups (groups A-D); groups C and D were stratified by age (1-5, 6-17, and 18-40 years). Participants in groups A-C were assigned to receive two 1·5 mL doses of Euvichol-S (three different lots) and participants in group D were assigned to receive the active control vaccine, Shanchol. All participants and site staff (with the exception of those who prepared and administered the study vaccines) were masked to group assignment. The primary immunogenicity endpoint was non-inferiority of immunogenicity of Euvichol-S (group C) versus Shanchol (group D) at 2 weeks after the second vaccine dose, measured by the seroconversion rate, defined as the proportion of participants who had achieved seroconversion (defined as ≥four-fold increase in V cholerae O1 Inaba and Ogawa titres compared with baseline). The primary immunogenicity endpoint was assessed in the per-protocol analysis set, which included all participants who received all their planned vaccine administrations, had no important protocol deviations, and who provided blood samples for all immunogenicity assessments. The primary safety endpoint was the number of solicited adverse events, unsolicited adverse events, and serious adverse events after each vaccine dose in all ages and each age stratum, assessed in all participants who received at least one dose of the Euvichol-S or Shanchol. Non-inferiority of Euvichol-S compared with Shanchol was shown if the lower limit of the 95% CI for the difference between the seroconversion rates in Euvichol-S group C versus Shanchol group D was above the predefined non-inferiority margin of -10%. The trial was registered at ClinicalTrials.gov, NCT04760236.
FINDINGS
Between Oct 6, 2021, and Jan 19, 2022, 2529 healthy participants (1261 [49·9%] males; 1268 [50·1%] females), were randomly assigned to group A (n=330; Euvichol-S lot number ES-2002), group B (n=331; Euvichol-S ES-2003), group C (n=934; Euvichol-S ES-2004]), or group D (n=934; Shanchol). Non-inferiority of Euvichol-S versus Shanchol in seroconversion rate for both serotypes at 2 weeks after the second dose was confirmed in all ages (difference in seroconversion rate for V cholerae O1 Inaba -0·00 [95% CI -1·86 to 1·86]; for V cholerae O1 Ogawa -1·62 [-4·80 to 1·56]). Treatment-emergent adverse events were reported in 244 (9·7%) of 2529 participants in the safety analysis set, with a total of 403 events; 247 events were reported among 151 (9·5%) of 1595 Euvichol-S recipients and 156 events among 93 (10·0%) of 934 Shanchol recipients. Pyrexia was the most common adverse event in both groups (57 events among 56 [3·5%] of 1595 Euvichol-S recipients and 37 events among 35 [3·7%] of 934 Shanchol recipients). No serious adverse events were deemed to be vaccine-related.
INTERPRETATION
A two-dose regimen of Euvichol-S vaccine was non-inferior to the active control vaccine, Shanchol, in terms of seroconversion rates 2 weeks after the second dose. The simplified formulation and production requirements of the Euvichol-S vaccine have the potential to increase the supply of oral cholera vaccine and reduce the gap between the current oral cholera vaccine supply and demand.
FUNDING
The Bill & Melinda Gates Foundation.
TRANSLATION
For the Nepali translation of the abstract see Supplementary Materials section.
Topics: Male; Pregnancy; Female; Humans; Cholera; Cholera Vaccines; Vibrio cholerae O1; Nepal; Lactation
PubMed: 38614631
DOI: 10.1016/S2214-109X(24)00059-7