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Frontiers in Microbiology 2023is a multi-host pathogenic species currently subdivided into five phylogenetic lineages (L) plus one pathovar with the ability to infect fish due to a transmissible...
is a multi-host pathogenic species currently subdivided into five phylogenetic lineages (L) plus one pathovar with the ability to infect fish due to a transmissible virulence plasmid. This plasmid (or a fragment of it) has been transmitted between lineages within the species, contributing to the evolution of . This study aimed to provide an experimental approximation to the mutation rate by determining spontaneous mutation rates from bacterial cultures of representants of the different lineages by whole-genome sequencing. To this purpose, synonymous SNP differences, i.e., spontaneous mutation not subjected to the evolutive forces, between initial and final culture after serial growth were evaluated and used for mutation rate calculation.
PubMed: 37621400
DOI: 10.3389/fmicb.2023.1223293 -
Access Microbiology 2023The stressosome is a protein complex that senses environmental stresses and mediates the stress response in several Gram-positive bacteria through the activation of the...
The stressosome is a protein complex that senses environmental stresses and mediates the stress response in several Gram-positive bacteria through the activation of the alternative sigma factor SigB. The stressosome locus is found in 44 % of Gram-negative isolates. However, does not possess SigB. Nonetheless, in nutrient-limited media, the stressosome modulates gene transcription and bacterial behaviour. In this work, the expression of the stressosome genes was proven during stationary phase in nutrient-rich media and co-transcription as one operonic unit of the stressosome locus and its putative downstream regulatory locus was demonstrated. The construction of a stressosome mutant lacking the genes encoding the four proteins constituting the stressosome complex (VvRsbR, VvRsbS, VvRsbT, VvRsbX) allowed us to examine the role of this complex . Extensive phenotypic characterization of the ΔRSTX mutant in nutrient-rich media showed that the stressosome does not contribute to growth of . Moreover, the stressosome did not modulate the tolerance or survival response of to the range of stresses tested, which included ethanol, hyperosmolarity, hypoxia, high temperature, acidity and oxidative stress. Furthermore, the stressosome was dispensable for motility and exoenzyme production of in nutrient-rich media. Therefore, in conclusion, although stressosome gene transcription occurs in nutrient-rich media, the stressosome neither has an essential role in stress responses of nor does it seem to modulate these activities in these conditions. We hypothesise that the stressosome is expressed in nutrient-rich conditions as a sensor complex, but that activation of the complex does not occur in this environment.
PubMed: 37601438
DOI: 10.1099/acmi.0.000523.v4 -
Heliyon Aug 2023is usually transmitted by consumption of raw or undercooked seafood or exposure to seawater and can causes gastroenteritis, wound infection, and even sepsis. However,...
is usually transmitted by consumption of raw or undercooked seafood or exposure to seawater and can causes gastroenteritis, wound infection, and even sepsis. However, atypical or unclear sources of infection have been reported. Here, we report a case of infection presenting as septicemia in a 53-year-old man with hepatitis B virus-associated cirrhosis. The source of infection remained unclear as the patient reported no consumption of seafood or contact with seawater. Treatment with antibiotics was initiated prior to confirmation of infection. This report provides an important reference for the diagnosis and treatment of infection.
PubMed: 37600364
DOI: 10.1016/j.heliyon.2023.e18905 -
PLoS Biology Aug 2023Antibiotic resistance is a continuously increasing concern for public healthcare. Understanding resistance mechanisms and their emergence is crucial for the development...
Antibiotic resistance is a continuously increasing concern for public healthcare. Understanding resistance mechanisms and their emergence is crucial for the development of new antibiotics and their effective use. The peptide antibiotic albicidin is such a promising candidate that, as a gyrase poison, shows bactericidal activity against a wide range of gram-positive and gram-negative bacteria. Here, we report the discovery of a gene amplification-based mechanism that imparts an up to 1000-fold increase in resistance levels against albicidin. RNA sequencing and proteomics data show that this novel mechanism protects Salmonella Typhimurium and Escherichia coli by increasing the copy number of STM3175 (YgiV), a transcription regulator with a GyrI-like small molecule binding domain that traps albicidin with high affinity. X-ray crystallography and molecular docking reveal a new conserved motif in the binding groove of the GyrI-like domain that can interact with aromatic building blocks of albicidin. Phylogenetic studies suggest that this resistance mechanism is ubiquitous in gram-negative bacteria, and our experiments confirm that STM3175 homologs can confer resistance in pathogens such as Vibrio vulnificus and Pseudomonas aeruginosa.
Topics: Gene Amplification; Anti-Bacterial Agents; Molecular Docking Simulation; Phylogeny; Gram-Negative Bacteria; Gram-Positive Bacteria
PubMed: 37561817
DOI: 10.1371/journal.pbio.3002186 -
Scientific Reports Aug 2023Grouper culture has been expanding in Malaysia due to the huge demand locally and globally. However, due to infectious diseases such as vibriosis, the fish mortality...
Oleic acid as potential immunostimulant in metabolism pathways of hybrid grouper fingerlings (Epinephelus fuscoguttatus × Epinephelus lanceolatus) infected with Vibrio vulnificus.
Grouper culture has been expanding in Malaysia due to the huge demand locally and globally. However, due to infectious diseases such as vibriosis, the fish mortality rate increased, which has affected the production of grouper. Therefore, this study focuses on the metabolic profiling of surviving infected grouper fed with different formulations of fatty acid diets that acted as immunostimulants for the fish to achieve desirable growth and health performance. After a six-week feeding trial and one-week post-bacterial challenge, the surviving infected grouper was sampled for GC-MS analysis. For metabolite extraction, a methanol/chloroform/water (2:2:1.8) extraction method was applied to the immune organs (spleen and liver) of surviving infected grouper. The distribution patterns of metabolites between experimental groups were then analyzed using a metabolomics platform. A total of 50 and 81 metabolites were putatively identified from the spleen and liver samples, respectively. Our further analysis identified glycine, serine, and threonine metabolism, and alanine, aspartate and glutamate metabolism had the most impacted pathways, respectively, in spleen and liver samples from surviving infected grouper. The metabolites that were highly abundant in the spleen found in these pathways were glycine (20.9%), l-threonine (1.0%) and l-serine (0.8%). Meanwhile, in the liver l-glutamine (1.8%) and aspartic acid (0.6%) were found to be highly abundant. Interestingly, among the fish diet groups, grouper fed with oleic acid diet produced more metabolites with a higher percent area compared to the control diets. The results obtained from this study elucidate the use of oleic acid as an immunostimulant in fish feed formulation affects more various immune-related metabolites than other formulated feed diets for vibriosis infected grouper.
Topics: Animals; Bass; Vibrio vulnificus; Oleic Acid; Diet; Vibrio Infections; Fish Diseases; Animal Feed
PubMed: 37553472
DOI: 10.1038/s41598-023-40096-7 -
Frontiers in Microbiology 2023Detecting and identifying the origins of foodborne pathogen outbreaks is a challenging. The Next-Generation Sequencing (NGS) panel method offers a potential solution by...
Detecting and identifying the origins of foodborne pathogen outbreaks is a challenging. The Next-Generation Sequencing (NGS) panel method offers a potential solution by enabling efficient screening and identification of various bacteria in one reaction. In this study, new NGS panel primer sets that target 18 specific virulence factor genes from six target pathogens (, , , , , and ) were developed and optimized. The primer sets were validated for specificity and selectivity through singleplex PCR, confirming the expected amplicon size. Crosscheck and multiplex PCR showed no interference in the primer set or pathogenic DNA mixture. The NGS panel analysis of spiked water samples detected all 18 target genes in a single reaction, with pathogen concentrations ranging from 10 to 10 colony-forming units (CFUs) per target pathogen. Notably, the total sequence read counts from the virulence factor genes showed a positive association with the CFUs per target pathogen. However, the method exhibited relatively low sensitivity and occasional false positive results at low pathogen concentrations of 10 CFUs. To validate the detection and identification results, two sets of quantitative real-time PCR (qPCR) analyses were independently performed on the same spiked water samples, yielding almost the same efficiency and specificity compared to the NGS panel analysis. Comparative statistical analysis and Spearman correlation analysis further supported the similarity of the results by showing a negative association between the NGS panel sequence read counts and qPCR cycle threshold (Ct) values. To enhance NGS panel analysis for better detection, optimization of primer sets and real-time NGS sequencing technology are essential. Nonetheless, this study provides valuable insights into applying NGS panel analysis for multiple foodborne pathogen detection, emphasizing its potential in ensuring food safety.
PubMed: 37520347
DOI: 10.3389/fmicb.2023.1179934 -
Vaccines Jul 2023Intracranial sarcoma is an uncommon aggressive cancer with a poor prognosis and a high recurrence rate. Although postoperative adjuvant radiotherapy (RT) is the most...
Intracranial sarcoma is an uncommon aggressive cancer with a poor prognosis and a high recurrence rate. Although postoperative adjuvant radiotherapy (RT) is the most recommended treatment strategy, it does not significantly improve survival rates. In this study, we used an attenuated strain engineered to secrete Vibrio vulnificus flagellin B (SLpFlaB) as an immunotherapy to assist with the antitumor effects of RT on intracranial sarcoma. In vitro, the expression of γH2AX and cleaved caspase-3 was analyzed by Western blot. In vivo detection of SLpFlaB colonization time in tumors was measured using an in vivo imaging system (IVIS). Tumor growth delay and elimination were demonstrated in an intracranial mouse model, and the distribution of macrophages, M1 macrophages, and CD8 cells after treatment was measured using FACS analysis. Our findings in vitro suggest that combination therapy increases S-180 radiosensitivity, the expression of DNA double-strand breaks, and programmed cell death. In vivo, combination treatment causes intracranial sarcoma to be eliminated without tumor recurrence and redistribution of immune cells in the brain, with data showing the enhanced migration and infiltration of CD8 T cells and macrophages, and an increased proportion of M1 macrophage polarization. Compared to RT alone, the combination therapy enhanced the radiosensitivity of S-180 cells, promoted the recruitment of immune cells at the tumor site, and prevented tumor recurrence. This combination therapy may provide a new strategy for treating intracranial sarcomas.
PubMed: 37515090
DOI: 10.3390/vaccines11071275 -
The Veterinary Quarterly Dec 2023an opportunistic human pathogen native to marine/estuarine environment, is one of the leading causes of death due to seafood consumption and exposure of wounds to...
an opportunistic human pathogen native to marine/estuarine environment, is one of the leading causes of death due to seafood consumption and exposure of wounds to seawater worldwide. The present study involves the whole genome sequence analysis of an environmental strain of (clinical genotype) isolated from seafood along the Mangaluru coast of India. The sequenced genome data was subjected to analysis of phylogeny, virulence genes, antimicrobial resistance determinants, and secretary proteins using suitable bioinformatics tools. The sequenced isolate had an overall genome length of 4.8 Mb and GC content of 46% with 4400 coding DNA sequences. The sequenced strain belongs to a new sequence type (Multilocus sequence typing) and was also found to branch with a phylogenetic lineage that groups the most infectious strains of . The seafood isolate had complete genes involved in conferring serum resistance yet showed limited serum resistance. The study identified several genes against the antibiotics that are commonly used in their treatment, highlighting the need for alternative treatments. Also, the secretory protein analysis revealed genes associated with major pathways like ABC transporters, two-component systems, quorum sensing, biofilm formation, cationic antimicrobial peptide (CAMP) resistance, and others that play a critical role in the pathogenesis of the . To the best of our knowledge, this is the first report of a detailed analysis of the genomic information of a isolated from the Indian subcontinent and provides evidence that raises public health concerns about the safety of seafood.
Topics: Humans; Animals; Vibrio vulnificus; Virulence; Phylogeny; Genotype; Seafood
PubMed: 37478018
DOI: 10.1080/01652176.2023.2240389 -
Frontiers in Microbiology 2023is a gram-negative, opportunistic pathogen common to warm waters worldwide. Human infection is rare and typically affects those residing in coastal areas during the...
BACKGROUND
is a gram-negative, opportunistic pathogen common to warm waters worldwide. Human infection is rare and typically affects those residing in coastal areas during the summer months, but it causes rapid deterioration and is fatal.
METHODS
The medical records of six patients with sepsis caused by infection who were treated at the First Affiliated Hospital of Ningbo University from 2020 to 2022 were retrospectively reviewed. The patient demographics, clinical symptoms, laboratory test results, treatments, and outcomes are summarized.
RESULTS
infection was confirmed by blood or pus culture, 16S ribosomal DNA sequencing, and metagenomic next-generation sequencing. All six patients were male with pre-existing liver diseases and two reported consuming seafood before the onset of symptoms. Of the six patients, four succumbed to the disease, two recovered, and one underwent leg amputation.
CONCLUSION
infection progresses rapidly and is highly fatal, thus prompt and aggressive treatment is necessary. infection should be considered in older (>40 years) patients with a history of liver disease and recent consumption of seafood or exposure to seawater, especially those residing in coastal areas during the summer months.
PubMed: 37469427
DOI: 10.3389/fmicb.2023.1220526 -
Medicine Jul 2023The diagnostic accuracy of laboratory risk indicator for necrotizing fasciitis (LRINEC) score system in specific Vibrio vulnificus (V vulnificus ) necrotizing fasciitis...
Unreliable diagnostic accuracy of laboratory risk indicator for necrotizing fasciitis (LRINEC) score but good outcome predictor in necrotizing fasciitis due to Vibrio vulnificus : A retrospective and matched-pair study.
The diagnostic accuracy of laboratory risk indicator for necrotizing fasciitis (LRINEC) score system in specific Vibrio vulnificus (V vulnificus ) necrotizing fasciitis (NF) have not been fully investigated yet. This aim of our study is to validate the LRINEC score in patients with V vulnificus NF. A retrospective study of hospitalized patients was conducted in a hospital in southern Taiwan between January 2015 and December 2022. Clinical characteristics, variables and outcomes were compared among V vulnificus NF, non- Vibrio NF and cellulitis patients. A total of 260 patients were included, 40 in V vulnificus NF group, 80 in non- Vibrio NF group and 160 patients in cellulitis group. In V vulnificus NF group with an LRINEC cutoff score ≥ 6, the sensitivity was 35% (95% confidence interval [CI]: 29%-41%), specificity was 81% (95% CI: 76%-86%), PPV was 23% (95% CI: 17%-27%), and NPV was 90% (95% CI: 88%-92%). The AUROC for accuracy of the LRINEC score in V vulnificus NF was 0.614 (95% CI: 0.592-0.636). Multi-variable logistic regression analysis revealed that LRINEC > 8 was significantly associated with higher in-hospital mortality (adjusted odds ratio = 1.57; 95% CI: 1.43-2.08; P < .01). The LRINEC score may not be an accurate tool for V vulnificus NF. That should be used with caution as a routine diagnostic tool. However, LRINEC > 8 is significantly associated with higher mortality in V vulnificus NF patients.
Topics: Humans; Fasciitis, Necrotizing; Retrospective Studies; Cellulitis; Vibrio vulnificus; Risk Factors
PubMed: 37417615
DOI: 10.1097/MD.0000000000034207