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Microorganisms Apr 2024Bacteria in the genus are ubiquitous in estuarine and coastal waters. Some species (including and are known human pathogens causing ailments like cholera, diarrhea,...
Bacteria in the genus are ubiquitous in estuarine and coastal waters. Some species (including and are known human pathogens causing ailments like cholera, diarrhea, or septicemia. Notably, can also cause a severe systemic infection (known as vibriosis) in eels raised in aquaculture facilities. Water samples were periodically collected from the estuary of the Asahi River, located in the southern part of Okayama City, Japan. These samples were directly plated onto CHROMagar Vibrio plates, and colonies displaying turquoise-blue coloration were selected. Thereafter, polymerase chain reaction was used to identify and . A total of 30 strains and 194 strains were isolated during the warm season when the water temperature (WT) was higher than 20 °C. Concurrently, an increase in coliforms was observed during this period. Notably, has two genotypes, designated as genotype 1 and genotype 2. Genotype 1 is pathogenic to humans, while genotype 2 is pathogenic to both humans and eels. The loop-mediated isothermal amplification method was developed to rapidly determine genotypes at a low cost. Of the 194 strains isolated, 80 (41.2%) were identified as genotype 1 strains. Among the 41 strains isolated when the WTs were higher than 28 °C, 25 strains (61.0%) belonged to genotype 1. In contrast, of the 32 strains isolated when the WTs were lower than 24 °C, 27 strains (84.4%) belonged to genotype 2. These results suggest that the distribution of the two genotypes was influenced by WT.
PubMed: 38792707
DOI: 10.3390/microorganisms12050877 -
The Journal of Medical Investigation :... 2024Vibrio vulnificus (V. vulnificus) is a halophilic gram-negative bacterium that inhabits coastal warm water and induce severe diseases such as primary septicemia. To...
Vibrio vulnificus (V. vulnificus) is a halophilic gram-negative bacterium that inhabits coastal warm water and induce severe diseases such as primary septicemia. To investigate the mechanisms of rapid bacterial translocation on intestinal infection, we focused on outer membrane vesicles (OMVs), which are extracellular vesicles produced by Gram-negative bacteria and deliver virulence factors. However, there are very few studies on the pathogenicity or contents of V. vulnificus OMVs (Vv-OMVs). In this study, we investigated the effects of Vv-OMVs on host cells. Epithelial cells INT407 were stimulated with purified OMVs and morphological alterations and levels of lactate dehydrogenase (LDH) release were observed. In cells treated with OMVs, cell detachment without LDH release was observed, which exhibited different characteristics from cytotoxic cell detachment observed in V. vulnificus infection. Interestingly, OMVs from a Vibrio Vulnificus Hemolysin (VVH) and Multifunctional-autoprocessing repeats-in -toxin (MARTX) double-deletion mutant strain also caused cell detachment without LDH release. Our results suggested that the proteolytic function of a serine protease contained in Vv-OMVs may contribute to pathogenicity of V. vulnificus by assisting bacterial translocation. This study reveals a new pathogenic mechanism during V. vulnificus infections. J. Med. Invest. 71 : 102-112, February, 2024.
Topics: Vibrio vulnificus; Humans; Extracellular Vesicles; Hemolysin Proteins; L-Lactate Dehydrogenase; Bacterial Outer Membrane; Epithelial Cells
PubMed: 38735705
DOI: 10.2152/jmi.71.102 -
Journal of Personalized Medicine Apr 2024is a genus of Gram-negative bacteria found in various aquatic environments, including saltwater and freshwater. bacteremia can lead to sepsis, a potentially...
BACKGROUND
is a genus of Gram-negative bacteria found in various aquatic environments, including saltwater and freshwater. bacteremia can lead to sepsis, a potentially life-threatening condition in which the immune system enters overdrive in response to the disease, causing widespread inflammation and damage to tissues and organs. had the highest case fatality rate (39%) of all reported foodborne infections in the United States and a high mortality rate in Asia, including Taiwan. Numerous scoring systems have been created to estimate the mortality risk in the emergency department (ED). However, there are no specific scoring systems to predict the mortality risk of bacteremia. Therefore, this study modified the existing scoring systems to better predict the mortality risk of bacteremia.
METHODS
Cases of bacteremia were diagnosed based on the results from at least one blood culture in the ED. Patient data were extracted from the electronic clinical database, covering January 2012 to December 2021. The primary outcome was in-hospital mortality.This study used univariate and multivariate analyses to evaluate the mortality risk.
RESULTS
This study enrolled 36 patients diagnosed with bacteremia, including 23 males (63.9%) and 13 females (36.1%), with a mean age of 65.1 ± 15.7 years. The in-hospital mortality rate amounted to 25% (9/36), with 31.5% in (6/19) and 17.6% in non- (3/17). The non-survivors demonstrated higher MEDS (10.3 ± 2.4) than the survivors (6.2 ± 4.1) ( = 0.002). Concerning the qSOFA, the survivors scored 0.3 ± 0.5, and the non-survivors displayed a score of 0.6 ± 0.7 ( = 0.387). The AUC of the ROC for the MEDS and qSOFA was 0.833 and 0.599, respectively. This study modified the scoring systems with other predictive factors, including BUN and pH. The AUC of the ROC for the modified MEDS and qSOFA reached up to 0.852 and 0.802, respectively.
CONCLUSION
The MEDS could serve as reliable indicators for forecasting the mortality rate of patients grappling with bacteremia. This study modified the MEDS and qSOFA to strengthen the predictive performance of mortality risk for bacteremia. We advocate the prompt initiation of targeted therapeutic interventions and judicious antibiotic treatments to curb fatality rates.
PubMed: 38673012
DOI: 10.3390/jpm14040385 -
Asian Journal of Surgery Apr 2024
PubMed: 38658273
DOI: 10.1016/j.asjsur.2024.04.072 -
Italian Journal of Food Safety Feb 2024The majority of human diseases attributed to seafood are caused by spp., and the most commonly reported species are , , and . The conventional methods for the detection...
Detection of pathogenic spp. in foods: polymerase chain reaction-based screening strategy to rapidly detect pathogenic , , and in bivalve mollusks and preliminary results.
The majority of human diseases attributed to seafood are caused by spp., and the most commonly reported species are , , and . The conventional methods for the detection of species involve the use of selective media, which are inexpensive and simple but time-consuming. The present work aimed to develop a rapid method based on the use of multiplex real-time polymerase chain reaction (PCR) to detect , , and in bivalve mollusks. 30 aliquots of bivalve mollusks () were experimentally inoculated with two levels of , , and . ISO 21872-1:2017 was used in parallel for qualitative analysis. The limit of detection of 50% was 7.67 CFU/g for , 0.024 CFU/g for , and 1.36 CFU/g for . For and , the real-time PCR protocol was demonstrated to amplify the pathogens in samples seeded with the lowest and highest levels. The molecular method evaluated showed a concordance rate of 100% with the reference microbiological method. was never detected in samples contaminated with the lowest level, and it was detected in 14 samples (93.33%) seeded with the highest concentration. In conclusion, the developed multiplex real-time PCR proved to be reliable for and Results for are promising, but further analysis is needed. The proposed method could represent a quick monitoring tool and, if used, would allow the implementation of food safety.
PubMed: 38623280
DOI: 10.4081/ijfs.2024.11635 -
Molecular Therapy. Oncology Mar 2024Cancer immunotherapy based on bioengineering of bacteria can effectively increase anticancer immune responses. However, few studies have investigated the antitumor...
Cancer immunotherapy based on bioengineering of bacteria can effectively increase anticancer immune responses. However, few studies have investigated the antitumor potential of engineering . Here, we genetically engineered to overexpress flagellin B (FlaB) protein in a murine CT26 tumor model. We found that a large number of FlaB-expressing colonized tumor tissues, enhanced T cell infiltration and secretion of cytokines and cytotoxic proteins in tumors, and significantly restrained tumor growth. Our results also showed that programmed death ligand 1 (PD-L1) expression in tumor-infiltrating immune cells was elevated after treatment with FlaB-expressing . In addition, combination therapy with FlaB-expressing and PD-L1 blockade synergistically improved antitumor efficacy by enhancing infiltration of CD8 cells. Furthermore, serum liver biochemical indices of mice increased in the short term in both the and the FlaB-expressing treatment groups but gradually recovered in the later stage of treatment so that FlaB protein expression did not increase the toxicity of . Taken together, our results suggest that could serve as an engineered bacterium for bacterium-based cancer immunotherapy.
PubMed: 38596299
DOI: 10.1016/j.omton.2024.200770 -
CMAJ : Canadian Medical Association... Apr 2024
Topics: Female; Humans; Adult; Fasciitis, Necrotizing; Vibrio vulnificus; Vibrio Infections
PubMed: 38589031
DOI: 10.1503/cmaj.231766 -
Microbiology Spectrum May 2024is a genus of halophilic, gram-negative bacteria found in estuaries around the globe. Integral parts of coastal cultures often involve contact with vectors of...
UNLABELLED
is a genus of halophilic, gram-negative bacteria found in estuaries around the globe. Integral parts of coastal cultures often involve contact with vectors of pathogenic spp. (e.g., consuming raw shellfish). High rates of mortality from certain spp. infections demonstrate the need for an improved understanding of spp. dynamics in estuarine regions. Our study assessed meteorological, hydrographic, and biological correlates of and at 10 sites in the Eastern Mississippi Sound System (EMSS) from April to October 2019. During the sampling period, median abundances of and were 2.31 log MPN/L and 2.90 log MPN/L, respectively. spp. dynamics were largely driven by site-based variation, with sites closest to freshwater inputs having the highest abundances. The E-W wind scalar, which affects Ekman transport, was a novel spp. correlate observed. A potential salinity effect on bacterial-particle associations was identified, where was associated with larger particles in conditions outside of their optimal salinity. Additionally, abundances were correlated to those of harmful algal species that did not dominate community chlorophyll. Correlates from this study may be used to inform the next iteration of regionally predictive models and may lend additional insight to spp. ecology in similar systems.
IMPORTANCE
spp. are bacteria found in estuaries worldwide; some species can cause illness and infections in humans. Relationships between spp. abundance, salinity, and temperature are well documented, but correlations to other environmental parameters are less understood. This study identifies unique correlates (e.g., E-W wind scalar and harmful algal species) that could potentially inform the next iteration of predictive models for the EMSS region. Additionally, these correlates may allow existing environmental monitoring efforts to be leveraged in providing data inputs for future Vibrio risk models. An observed correlation between salinity and /particle-size associations suggests that predicted environmental changes may affect the abundance of spp. in certain reservoirs, which may alter which vectors present the greatest vibrio risk.
Topics: Vibrio parahaemolyticus; Vibrio vulnificus; Estuaries; Alabama; Population Dynamics; Salinity; Vibrio Infections; Seawater; Water Microbiology
PubMed: 38578091
DOI: 10.1128/spectrum.03674-23 -
MBio May 2024Bacterial enhancer-binding proteins (bEBPs) acquire a transcriptionally active state via phosphorylation. However, transcriptional activation by the dephosphorylated...
Bacterial enhancer-binding proteins (bEBPs) acquire a transcriptionally active state via phosphorylation. However, transcriptional activation by the dephosphorylated form of bEBP has been observed in DctD, which belongs to Group I bEBP. The formation of a complex between dephosphorylated DctD (d-DctD) and dephosphorylated IIA (d-IIA) is a prerequisite for the transcriptional activity of d-DctD. In the present study, characteristics of the transcriptionally active complex composed of d-IIA and phosphorylation-deficient DctD (DctD) of were investigated in its multimeric conformation and DNA-binding ability. DctD formed a homodimer that could not bind to the DNA. In contrast, when DctD formed a complex with d-IIA in a 1:1 molar ratio, it produced two conformations: dimer and dodecamer of the complex. Only the dodecameric complex exhibited ATP-hydrolyzing activity and DNA-binding affinity. For successful DNA-binding and transcriptional activation by the dodecameric d-IIA/DctD complex, extended upstream activator sequences were required, which encompass the nucleotide sequences homologous to the known DctD-binding site and additional nucleotides downstream. This is the first report to demonstrate the molecular characteristics of a dephosphorylated bEBP complexed with another protein to form a transcriptionally active dodecameric complex, which has an affinity for a specific DNA-binding sequence.IMPORTANCEResponse regulators belonging to the bacterial two-component regulatory system activate the transcription initiation of their regulons when they are phosphorylated by cognate sensor kinases and oligomerized to the appropriate multimeric states. Recently, it has been shown that a dephosphorylated response regulator, DctD, could activate transcription in a phosphorylation-independent manner in . The dephosphorylated DctD activated transcription as efficiently as phosphorylated DctD when it formed a complex with dephosphorylated form of IIA, a component of the glucose-phosphotransferase system. Functional mimicry of this complex with the typical form of transcriptionally active phosphorylated DctD led us to study the molecular characteristics of this heterodimeric complex. Through systematic analyses, it was surprisingly determined that a multimer constituted with 12 complexes gained the ability to hydrolyze ATP and recognize specific upstream activator sequences containing a typical inverted-repeat sequence flanked by distinct nucleotides.
Topics: Phosphorylation; Bacterial Proteins; Vibrio vulnificus; Protein Binding; Gene Expression Regulation, Bacterial; Transcriptional Activation; Adenosine Triphosphate; DNA-Binding Proteins; Protein Multimerization; Transcription, Genetic; Transcription Factors
PubMed: 38564689
DOI: 10.1128/mbio.00330-24 -
Microorganisms Mar 2024With rising infection rates in recent years, poses an increasing threat to public safety in the coastal brackish Baltic Sea. It is therefore important to monitor this...
With rising infection rates in recent years, poses an increasing threat to public safety in the coastal brackish Baltic Sea. It is therefore important to monitor this organism and assess the infection risk on a more regular basis. However, as the coastline of the Baltic Sea is 8000 km long and shared by nine nations, a convenient, fast, inexpensive, yet efficient identification method is essential. We evaluated the effectiveness of a two-step agar-based approach consisting of successive isolation and cultivation on thiosulphate-citrate-bile salt sucrose (TCBS) agar and CHROMagar™ for in comparison with , , and . Our study contains isolates from water and sediment across a broad expanse of the Baltic Sea including 13 locations and two different summers, the time of year during which infections are usually much more frequent. Confirmation of isolate species identity was carried out using molecular analyses. The two-step agar plating method performed well across different locations and timeframes in correctly identifying by more than 80%, but the sensitivity in other species varied. Thus, our approach yielded promising results as a potential tool for early detection across a broad timeframe and transect of the Baltic Sea and potentially other brackish environments.
PubMed: 38543665
DOI: 10.3390/microorganisms12030614