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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 -
International Journal of Molecular... May 2024is an emerging foodborne pathogenic bacterium that can cause severe cholera-like diarrhea and various extraintestinal infections, posing challenges to public health and...
is an emerging foodborne pathogenic bacterium that can cause severe cholera-like diarrhea and various extraintestinal infections, posing challenges to public health and food safety worldwide. The arginine deiminase (ADI) pathway plays an important role in bacterial environmental adaptation and pathogenicity. However, the biological functions and regulatory mechanisms of the pathway in remain unclear. In this study, we demonstrate that L-arginine upregulates the expression of the ADI gene cluster and promotes the growth of . The ADI gene cluster, which we proved to be comprised of two operons, and , significantly enhances the survival of in acidic environments both in vitro (in culture medium and in macrophage) and in vivo (in mice). The mRNA level and reporter gene fusion analyses revealed that ArgR, a transcriptional factor, is necessary for the activation of both and transcriptions. Bioinformatic analysis predicted the existence of multiple potential ArgR binding sites at the and promoter regions that were further confirmed by electrophoretic mobility shift assay, DNase I footprinting, or point mutation analyses. Together, our study provides insights into the important role of the ArgR-ADI pathway in the survival of under acidic conditions and the detailed molecular mechanism. These findings will deepen our understanding of how environmental changes and gene expression interact to facilitate bacterial adaptations and virulence.
Topics: Animals; Gene Expression Regulation, Bacterial; Bacterial Proteins; Mice; Hydrolases; Promoter Regions, Genetic; Operon; Repressor Proteins; Vibrio; Arginine; Multigene Family; Virulence; Microbial Viability
PubMed: 38891866
DOI: 10.3390/ijms25115679 -
Internal Medicine (Tokyo, Japan) Mar 2024Vibrio fluvialis is a bacterium that can be found in both seawater and freshwater, and it is responsible for causing gastroenteritis and cholangitis. V. fluvialis...
Vibrio fluvialis is a bacterium that can be found in both seawater and freshwater, and it is responsible for causing gastroenteritis and cholangitis. V. fluvialis bacteremia has rarely been reported. We report a case of V. fluvialis bacteremia due to cholangitis in an immunocompetent adult who was exposed to seawater regularly as a sushi chef. The increased risk of V. fluvialis entry into the body resulting from frequent consumption of raw fish and regular exposure to seawater, bile outflow impairment caused by transient inflammation of the bile duct, and the presence of multiple bile acid resistance-related genes in V. fluvialis may lead to the development of acute cholangitis and subsequent bacteremia in immunocompetent patients.
PubMed: 38432963
DOI: 10.2169/internalmedicine.3078-23 -
Frontiers in Pharmacology 2023Although medicinal plants have been used by ethnic communities since ancient times to prevent and treat various diseases, only a few have been scientifically documented.... (Review)
Review
Although medicinal plants have been used by ethnic communities since ancient times to prevent and treat various diseases, only a few have been scientifically documented. Therefore, due to their rare availability and lack of comprehensive scientific information, we reviewed the ethnomedicinal uses, phytochemistry, and pharmacological activities of plants within the genus . To do this, we used specific search terms and phrases to retrieve relevant information from online sources published in English from 2000 to July 2023. The results showed that there are only two plants in the genus ( Sparrm. and Hutch.), which are traditionally used to treat a wide range of diseases, especially cancer, and skin, gastrointestinal, and urinogenital tract ailments in humans, and to cure animals in ethnoveterinary practices. It was noted that 13 secondary metabolites have been isolated from the two plants, the most prominent of which are flavonoids (diinsininol, diinsinin, and naringenin). The antioxidant activity of . is reported based on the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC: 4.26 ± 0.22 μg/mL) and 2 -2'-Azino-di-[3-ethylbenzthiazoline sulfonate (ABTS) radicals (IC: 4.62 ± 0.14 μg/mL), chelating iron (IC: 1.82 ± 0.01 μg/mL, 3.50 ± 0.09 μg/mL), and nitric oxide (IC: 9.97 ± 0.88 μg/mL, 9.09 ± 0.11 μg/mL). The methanolic stem extracts of possess antimicrobial activity against and , with minimum inhibitory concentration (MIC) values ranging from 0.16 to 0.625 mg/mL, and a minimum bactericidal concentration (MBC) of 1.25 to 5 mg/mL. Cytotoxic effects of the extracts from the two plant species were also demonstrated. possesses therapeutic potential as evidenced by the inhibitory effects of the aqueous rhizome extract on edema (1,000 mg/kg) and prostaglandin synthesis (IC = 0.2 mg/mL). In addition, diinsininol and diinsinin were isolated from inhibited prostaglandin synthesis (IC: 9.20 µM, 13.14 µM) and platelet-activating factor-induced exocytosis. Therefore, based on this review, further scientific research is needed to demystify the links between traditional medicinal uses, various secondary metabolites, and the pharmacology of the two plants.
PubMed: 38259280
DOI: 10.3389/fphar.2023.1301672 -
Cureus Jul 2023is a pathogenic Gram-negative bacillus typically resulting in gastroenteritis in humans. It has recently been identified as a growing concern for public health. The...
is a pathogenic Gram-negative bacillus typically resulting in gastroenteritis in humans. It has recently been identified as a growing concern for public health. The case presented is an uncommon case of causing bacteremia, as well as hemorrhagic skin lesions. Other reported cases have also highlighted unexpected manifestations, such as cerebritis, bacterial peritonitis, and otitis externa. These atypical presentations can happen in immunocompromised individuals. There are no established guidelines currently for the treatment of bacteremia. This case presents bacteremia that improved with doxycycline without the need for incision and drainage of the patient's lower extremity lesions.
PubMed: 37521591
DOI: 10.7759/cureus.42612 -
International Journal of Infectious... Apr 2024South Asia remains home to foodborne diseases caused by the Vibrio species. We aimed to compile and update information on the epidemiology of vibriosis in South Asia. (Meta-Analysis)
Meta-Analysis
OBJECTIVES
South Asia remains home to foodborne diseases caused by the Vibrio species. We aimed to compile and update information on the epidemiology of vibriosis in South Asia.
METHODS
For this systematic review and meta-analysis, we searched PubMed, Web of Science, EMBASE, and Google Scholar for studies related to vibriosis in South Asia published up to May 2023. A random-effects meta-analysis was used to estimate the pooled isolation rate of non-cholera-causing Vibrio species.
RESULTS
In total, 38 studies were included. Seven of these were case reports and 22 were included in the meta-analysis. The reported vibriosis cases were caused by non-O1/non-O139 V. cholerae, V. parahaemolyticus, V. fluvialis, and V. vulnificus. The overall pooled isolation rate was 4.0% (95% confidence interval [CI] 3.0-5.0%) in patients with diarrhea. Heterogeneity was high (I = 98.0%). The isolation rate of non-O1/non-O139 V. cholerae, V. parahaemolyticus, and V. fluvialis were 9.0 (95% CI 7.0-10.0%), 1.0 (95% CI 1.0-2.0%), and 2.0 (95% CI: 1.0-3.0%), respectively. Regarding V. parahaemolyticus, O3:K6 was the most frequently isolated serotype. Cases peaked during summer. Several studies reported antibiotic-resistant strains and those harboring extended-spectrum beta-lactamases genes.
CONCLUSIONS
This study demonstrates a high burden of infections caused by non-cholera-causing Vibrio species in South Asia.
Topics: Humans; Vibrio cholerae; Vibrio Infections; Foodborne Diseases; Diarrhea; Asia, Southern
PubMed: 38311027
DOI: 10.1016/j.ijid.2024.01.022 -
Bioresources and Bioprocessing Nov 2023(+)-Neomenthylamine is an important industrial precursor used to synthesize high value-added chemicals. Here, we report a novel biocatalytic route to synthesize...
(+)-Neomenthylamine is an important industrial precursor used to synthesize high value-added chemicals. Here, we report a novel biocatalytic route to synthesize (+)-neomenthylamine by amination of readily available (-)-menthone substrate using ω-transaminase. By screening a panel of ω-transaminases, an ω-transaminase from Vibrio fluvialis JS17 was identified with considerable amination activity to (-)-menthone, and then characterization of enzymatic properties was conducted for the enzyme. Under optimized conditions, 10 mM (-)-menthone was transformed in a mild aqueous phase with 4.7 mM product yielded in 24 h. The biocatalytic route using inexpensive starting materials (ketone substrate and amino donor) and mild reaction conditions represents an easy and green approach for (+)-neomenthylamine synthesis. This method underscores the potential of biocatalysts in the synthesis of unnatural terpenoid amine derivatives.
PubMed: 38647910
DOI: 10.1186/s40643-023-00693-w -
Complete genomic sequence of strain IDH5335 isolated from a patient with diarrhea in Kolkata, India.Microbiology Resource Announcements Dec 2023We isolated a strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this...
We isolated a strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this organism, which was obtained by combining Illumina and Oxford Nanopore sequencing data.
PubMed: 37943041
DOI: 10.1128/MRA.00707-23 -
Frontiers in Microbiology 2023High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments....
High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments. Previously we showed that the HHP-inducible trimethylamine N-oxide (TMAO) reductase improves the pressure tolerance of deep-sea strain QY27. Here, we investigated the molecular mechanism of HHP-responsive regulation of TMAO reductase TorA. By constructing and deletion mutants, we demonstrated that the two-component regulator TorR and sensor TorS are responsible for the HHP-responsive regulation of . Unlike known HHP-responsive regulatory system, the abundance of and was not affected by HHP. Complementation of the Δ mutant with TorS altered at conserved phosphorylation sites revealed that the three sites were indispensable for substrate-induced regulation, but only the histidine located in the alternative transmitter domain was involved in pressure-responsive regulation. Taken together, we demonstrated that the induction of TMAO reductase by HHP is mediated through the TorRS system and proposed a bifurcation of signal transduction in pressure-responsive regulation from the substrate-induction. This work provides novel knowledge of the pressure regulated gene expression and will promote the understanding of the microbial adaptation to the deep-sea HHP environment.
PubMed: 38029070
DOI: 10.3389/fmicb.2023.1291578 -
Journal of Global Antimicrobial... Dec 2023
Topics: Genomic Islands; Salmonella; beta-Lactamases
PubMed: 37748579
DOI: 10.1016/j.jgar.2023.09.014