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Microbial Pathogenesis Aug 2023Type II secretion systems (T2SS) are important molecular machines used by bacteria to transport a wide range of proteins across the outer membrane from the periplasm....
Type II secretion systems (T2SS) are important molecular machines used by bacteria to transport a wide range of proteins across the outer membrane from the periplasm. Vibrio mimicus is an epidemic pathogen threats to both aquatic animals and human health. Our previous study demonstrates that T2SS deletion reduced virulence by 307.26 times in yellow catfish. However, the specific effects of T2SS-mediated extracellular protein secretion in V. mimicus, including its potential role in exotoxin secretion or other mechanisms, require further investigation. Through proteomics and phenotypic analyses, this study observed that the ΔT2SS strain exhibited significant self-aggregation and dynamic deficiency, with a notable negative correlation with subsequent biofilm formation. The proteomics analysis revealed 239 different abundances of extracellular proteins after T2SS deletion, including 19 proteins with higher abundance and 220 proteins with lower and even absent in the ΔT2SS strain. These extracellular proteins are involved in various pathways, such as metabolism, virulence factors expression, and enzymes. Among them, purine, pyruvate, and pyrimidine metabolism, and the Citrate cycle, were the primary pathways affected by T2SS. Our phenotypic analysis is consistent with these findings, suggesting that the decreased virulence of ΔT2SS strains is due to the effect of T2SS on these proteins, which negatively impacts growth, biofilm formation, auto-aggregation, and motility of V. mimicus. These results provide valuable insights for designing deletion targets for attenuated vaccines development against V. mimicus and expand our understanding of the biological functions of T2SS.
Topics: Animals; Humans; Type II Secretion Systems; Vaccines, Attenuated; Bacterial Proteins; Virulence; Virulence Factors
PubMed: 37380063
DOI: 10.1016/j.micpath.2023.106215 -
Fish & Shellfish Immunology Apr 2024Vibrio mimicus is a pathogenic bacterium that cause red body disease in Macrobrachium nipponense, leading to high mortality and financial loss. Based on previous...
Vibrio mimicus is a pathogenic bacterium that cause red body disease in Macrobrachium nipponense, leading to high mortality and financial loss. Based on previous studies, rpoS gene contribute to bacterial pathogenicity during infection, but the role of RpoS involved in the immune response of M. nipponense under V. mimicus infection remains unclear. In this study, the pathogen load and the RNA-seq of M. nipponense under wild-type and ΔrpoS strain V. mimicus infection were investigated. Over the entire infection period, the ΔrpoS strain pathogen load was always lower than that of the wild-type strain in the M. nipponense hemolymph, hepatopancreas, gill and muscle. Furthermore, the expression level of rpoS gene in the hepatopancreas was the highest at 24 hours post infection (hpi), then the samples of hepatopancreas tissue infected with the wild type and ΔrpoS strain at 24 hpi were selected for RNA-seq sequencing. The results revealed a significant change in the transcriptomes of the hepatopancreases infected with ΔrpoS strain. In contrast to the wild-type infected group, the ΔrpoS strain infected group exhibited differentially expressed genes (DEGs) enriched in 181 KEGG pathways at 24 hpi. Among these pathways, 8 immune system-related pathways were enriched, including ECM-receptor interaction, PI3K-Akt signaling pathway, Rap1 signaling pathway, Gap junction, and Focal adhesion, etc. Among these pathways, up-regulated genes related to Kazal-type serine protease inhibitors, S-antigen protein, copper zinc superoxide dismutase, tight junction protein, etc. were enriched. This study elucidates that rpoS can affect tissue bacterial load and immune-related pathways, thereby impacting the survival rate of M. nipponense under V. mimicus infection. These findings validate the potential of rpoS as a promising target for the development of a live attenuated vaccine against V. mimicus.
Topics: Animals; Palaemonidae; Vibrio mimicus; Phosphatidylinositol 3-Kinases; Transcriptome; Vibrio Infections; Immunity
PubMed: 38342414
DOI: 10.1016/j.fsi.2024.109440 -
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 -
The Pan African Medical Journal 2024as cholera, due to toxigenic bacteria Vibrio cholera (serogroups O1 and O139), is a major public health threat in Africa, the aim of this work was to investigate...
INTRODUCTION
as cholera, due to toxigenic bacteria Vibrio cholera (serogroups O1 and O139), is a major public health threat in Africa, the aim of this work was to investigate potentially pathogenic Vibrionaceae bacteria firstly from human stool samples, and secondly from various environmental water points of Saint-Louis city in Senegal.
METHODS
a hospital-based study was conducted between 2013 and 2015. Stool samples were taken and cultured from daily incoming patients or hospitalized for acute diarrhea at Saint-Louis´ regional hospital. For environment, a monthly longitudinal sampling from January to October 2016 was carried out at 10 sites in the city. We used total DNA extracted from APW (alkaline peptone water) broth solutions and on suspect bacterial colonies to run PCR Multiplex targeting specific DNA fragments to detect Vibrio genus and specific species. In case of positivity, a simplex PCR was performed to test for cholera toxins Ctx, and V. parahaemolyticus TRH and TDH.
RESULTS
for 43 patients screened, bacterial culture was positive in 6% of cases but no strain of V. cholerae or other Vibrio sp. was isolated. PCR on 90 APW solutions were positive for Vibrio sp.(n = 43), V. cholera(n = 27), V. mimicus(n = 16), V. parahaemolyticus(8), V. alginolyticus(n = 4), and V. vulnificus(n = 2). Unlike for those on suspected colonies which were positive for a majority of V. parahaemolyticus (n = 40) and V. cholerae non-O1 / O139 (n = 35). Six strains of V. parahaemolyticus carried TRH gene, 3 of which expressed simultaneously virulence TRH and TDH genes. For physicochemical parameters, all temperatures varied similarly according to a unimodal seasonality, as well as salinity.
CONCLUSION
despite the presence of natural populations of Vibrionaceae, even toxigenic ones, was noted in water environment, along with favorable habitat conditions that could play a role in transmission of Vibriosis in the Saint Louis population, we did not isolate any of them from patients screened at the hospital.
Topics: Humans; Senegal; Cholera; Feces; Polymerase Chain Reaction; Diarrhea; Water Microbiology; Vibrionaceae; Vibrio; DNA, Bacterial; Vibrio cholerae; Adult; Female; Male
PubMed: 38946740
DOI: 10.11604/pamj.2024.48.5.34685 -
Frontiers in Microbiology 2023HtpG, a bacterial homolog of the eukaryotic 90 kDa heat-shock protein (Hsp90), represents the simplest member of the heat shock protein family. While the significance of...
HtpG, a bacterial homolog of the eukaryotic 90 kDa heat-shock protein (Hsp90), represents the simplest member of the heat shock protein family. While the significance of Hsp90 in fungal and cancer drug resistance has been confirmed, the role of HtpG in bacterial antibiotic resistance remains largely unexplored. This research aims to investigate the impact of the gene on antibiotic resistance in . Through the creation of gene deletion and complementation strains, we have uncovered the essential role of in regulating the structural integrity of the bacterial cell envelope. Our transcriptomics analysis demonstrates that the deletion of increases the sensitivity of to antimicrobial peptides, primarily due to upregulated lipopolysaccharide synthesis, reduced glycerophospholipid content, and weakened efflux pumps activity. Conversely, reduced sensitivity to β-lactam antibiotics in the Δ strain results from decreased peptidoglycan synthesis and dysregulated peptidoglycan recycling and regulation. Further exploration of specific pathway components is essential for a comprehensive understanding of -mediated resistance mechanisms, aiding in the development of antimicrobial agents. To our knowledge, this is the first effort to explore the relationship between and drug resistance in bacteria.
PubMed: 38239724
DOI: 10.3389/fmicb.2023.1295065 -
Frontiers in Microbiology 2024[This corrects the article DOI: 10.3389/fmicb.2023.1295065.].
[This corrects the article DOI: 10.3389/fmicb.2023.1295065.].
PubMed: 38544864
DOI: 10.3389/fmicb.2024.1381070