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Marine Drugs Dec 2021is a Gram-negative pathogenic bacterium that causes serious infections in humans and requires iron for growth. A clinical isolate, . M2799, secretes a catecholate... (Review)
Review
is a Gram-negative pathogenic bacterium that causes serious infections in humans and requires iron for growth. A clinical isolate, . M2799, secretes a catecholate siderophore, vulnibactin, that captures ferric ions from the environment. In the ferric-utilization system in . M2799, an isochorismate synthase (ICS) and an outer membrane receptor, VuuA, are required under low-iron conditions, but alternative proteins FatB and VuuB can function as a periplasmic-binding protein and a ferric-chelate reductase, respectively. The vulnibactin-export system is assembled from TolCV1 and several RND proteins, including VV1_1681. In heme acquisition, HupA and HvtA serve as specific outer membrane receptors and HupB is a sole periplasmic-binding protein, unlike FatB in the ferric-vulnibactin utilization system. We propose that ferric-siderophore periplasmic-binding proteins and ferric-chelate reductases are potential targets for drug discovery in infectious diseases.
Topics: Animals; Aquatic Organisms; Ions; Iron; Periplasmic Binding Proteins; Vibrio vulnificus
PubMed: 34940709
DOI: 10.3390/md19120710 -
Frontiers in Microbiology 2021Foodborne illness caused by pathogenic Vibrios is generally associated with the consumption of raw or undercooked seafood. Fish and other seafood can be contaminated... (Review)
Review
Foodborne illness caused by pathogenic Vibrios is generally associated with the consumption of raw or undercooked seafood. Fish and other seafood can be contaminated with Vibrio species, natural inhabitants of the marine, estuarine, and freshwater environment. Pathogenic Vibrios of major public health concerns are , , and . Common symptoms of foodborne Vibrio infection include watery diarrhea, stomach cramping, nausea, vomiting, fever, and chills. Administration of oral or intravenous rehydration salts solution is the mainstay for the management of cholera, and antibiotics are also used to shorten the duration of diarrhea and to limit further transmission of the disease. Currently, doxycycline, azithromycin, or ciprofloxacin are commonly used for , and doxycycline or quinolone are administered for , whereas doxycycline and a third-generation cephalosporin are recommended for as initial treatment regimen. The emergence of antimicrobial resistance (AMR) in Vibrios is increasingly common across the globe and a decrease in the effectiveness of commonly available antibiotics poses a global threat to public health. Recent progress in comparative genomic studies suggests that the genomes of the drug-resistant Vibrios harbor mobile genetic elements like plasmids, integrating conjugative elements, superintegron, transposable elements, and insertion sequences, which are the major carriers of genetic determinants encoding antimicrobial resistance. These mobile genetic elements are highly dynamic and could potentially propagate to other bacteria through horizontal gene transfer (HGT). To combat the serious threat of rising AMR, it is crucial to develop strategies for robust surveillance, use of new/novel pharmaceuticals, and prevention of antibiotic misuse.
PubMed: 34276582
DOI: 10.3389/fmicb.2021.638331 -
Infection & Chemotherapy Jun 2020infection was first reported as a necrotizing skin disease of unknown cause in Korea in 1979. In the early days, this disease caused panic across the country due to... (Review)
Review
infection was first reported as a necrotizing skin disease of unknown cause in Korea in 1979. In the early days, this disease caused panic across the country due to dreadful wound and its high mortality. Since then, the nature of the disease has become better understood and the overwhelming public fear has dissipated. However, there are still a certain number of infected patients each year and the high mortality rate remains a major health and social problem. From this review on historical and clinical perspective, better understanding of infection would provide valuable information for public health planning.
PubMed: 32468743
DOI: 10.3947/ic.2020.52.2.245 -
The Journal of Biological Chemistry Jul 2019On the fiftieth anniversary of the discovery of the Ser-His-Asp catalytic triad, perhaps the most unusual variation on the textbook classic is described: An incomplete...
On the fiftieth anniversary of the discovery of the Ser-His-Asp catalytic triad, perhaps the most unusual variation on the textbook classic is described: An incomplete catalytic triad in a hydrolase is rescued by a chloride ion (Fig. 1). Structural and functional data provide compelling evidence that the active site of a phospholipase from employs the anion in place of the commonly observed Asp, reminding us that even well-trodden scientific ground has surprises in store.
Topics: Catalysis; Catalytic Domain; Chlorides; Hydrolases; Hydrolysis
PubMed: 31350284
DOI: 10.1074/jbc.H119.009687 -
Evolutionary Bioinformatics Online 2022is an emergent marine pathogen and is the cause of a deadly septicemia. However, the evolution mechanism of antibiotic-resistant genes (ARGs) is still unclear....
is an emergent marine pathogen and is the cause of a deadly septicemia. However, the evolution mechanism of antibiotic-resistant genes (ARGs) is still unclear. Twenty-two high-quality complete genomes of were obtained and grouped into 16 clinical isolates and 6 environmental isolates. Genomic annotations found 23 ARG orthologous genes, among which 14 ARGs were shared by and other members. Furthermore, those ARGs were located in their chromosomes, rather than in the plasmids. Phylogenomic reconstruction based on single-copy orthologous protein sequences and ARG protein sequences revealed that clinical and environmental isolates were in a scattered distribution. The calculation of non-synonymous and synonymous substitutions indicated that most of ARGs evolved under purifying selection with the / ratios lower than one, while , and in several clinical isolates evolved under the positive selection with / ratios >1. Our result indicated that antibiotic-resistant armory was not only confined to clinical isolates, but to environmental ones as well and clinical isolates inclined to accumulate beneficial non-synonymous substitutions that could be retained to improve competitiveness.
PubMed: 36404992
DOI: 10.1177/11769343221134400 -
Disease Models & Mechanisms Aug 2023Transgene driven expression of Escherichia coli nitroreductase (NTR1.0) renders animal cells susceptible to the antibiotic metronidazole (MTZ). Many NTR1.0/MTZ ablation...
Transgene driven expression of Escherichia coli nitroreductase (NTR1.0) renders animal cells susceptible to the antibiotic metronidazole (MTZ). Many NTR1.0/MTZ ablation tools have been reported in zebrafish, which have significantly impacted regeneration studies. However, NTR1.0-based tools are not appropriate for modeling chronic cell loss as prolonged application of the required MTZ dose (10 mM) is deleterious to zebrafish health. We established that this dose corresponds to the median lethal dose (LD50) of MTZ in larval and adult zebrafish and that it induced intestinal pathology. NTR2.0 is a more active nitroreductase engineered from Vibrio vulnificus NfsB that requires substantially less MTZ to induce cell ablation. Here, we report on the generation of two new NTR2.0-based zebrafish lines in which acute β-cell ablation can be achieved without MTZ-associated intestinal pathology. For the first time, we were able to sustain β-cell loss and maintain elevated glucose levels (chronic hyperglycemia) in larvae and adults. Adult fish showed significant weight loss, consistent with the induction of a diabetic state, indicating that this paradigm will allow the modeling of diabetes and associated pathologies.
Topics: Animals; Zebrafish; Hyperglycemia; Metronidazole; Diabetes Mellitus; Nitroreductases; Animals, Genetically Modified
PubMed: 37401381
DOI: 10.1242/dmm.050215 -
Applied and Environmental Microbiology Jun 2023Incidence of vibriosis is rising globally, with evidence that changing climatic conditions are influencing environmental factors that enhance growth of pathogenic spp....
Incidence of vibriosis is rising globally, with evidence that changing climatic conditions are influencing environmental factors that enhance growth of pathogenic spp. in aquatic ecosystems. To determine the impact of environmental factors on occurrence of pathogenic spp., samples were collected in the Chesapeake Bay, Maryland, during 2009 to 2012 and 2019 to 2022. Genetic markers for Vibrio vulnificus () and Vibrio parahaemolyticus (, , and ) were enumerated by direct plating and DNA colony hybridization. Results confirmed seasonality and environmental parameters as predictors. Water temperature showed a linear correlation with and , and two critical thresholds were observed, an initial increase in detectable numbers (>15°C) and a second increase when maximum counts were recorded (>25°C). Temperature and pathogenic V. parahaemolyticus ( and ) were not strongly correlated; however, the evidence showed that these organisms persist in oyster and sediment at colder temperatures. Salinity (10 to 15 ppt), total chlorophyll (5 to 25 μg/L), dissolved oxygen (5 to 10 mg/L), and pH (8) were associated with increased abundance of and . Importantly, a long-term increase in spp. numbers was observed in water samples between the two collection periods, specifically at Tangier Sound (lower bay), with the evidence suggesting an extended seasonality for these bacteria in the area. Notably, showed a mean positive increase that was ca. 3-fold overall, with the most significant increase observed during the fall. In conclusion, vibriosis continues to be a risk in the Chesapeake Bay region. A predictive intelligence system to assist decision makers, with respect to climate and human health, is warranted. The genus includes pathogenic species that are naturally occurring in marine and estuarine environments globally. Routine monitoring for species and environmental parameters influencing their incidence is critical to provide a warning system for the public when the risk of infection is high. In this study, occurrence of Vibrio parahaemolyticus and Vibrio vulnificus, both potential human pathogens, in Chesapeake Bay water, oysters, and sediment samples collected over a 13-year period was analyzed. The results provide a confirmation of environmental predictors for these bacteria, notably temperature, salinity, and total chlorophyll , and their seasonality of occurrence. New findings refine environmental parameter thresholds of culturable species and document a long-term increase in populations in the Chesapeake Bay. This study provides a valuable foundation for development of predicative risk intelligence models for incidence during climate change.
Topics: Animals; Humans; Vibrio parahaemolyticus; Vibrio vulnificus; Chlorophyll A; Ecosystem; Ostreidae; Vibrio Infections; Water
PubMed: 37222620
DOI: 10.1128/aem.00307-23 -
Trends in Microbiology Dec 2022The fulminating zoonotic pathogen Vibrio vulnificus is the causative agent of fatal septicemia in humans and fish, raising tremendous economic burdens in healthcare and... (Review)
Review
The fulminating zoonotic pathogen Vibrio vulnificus is the causative agent of fatal septicemia in humans and fish, raising tremendous economic burdens in healthcare and the aquaculture industry. V. vulnificus exploits various virulence factors, including biofilm-related factors and exotoxins, for its persistence in nature and pathogenesis during infection. Substantial studies have found that the expression of virulence factors is coordinately regulated by numerous transcription factors that recognize the changing environments. Here, we summarize and discuss the recent discoveries of the physiological roles of virulence factors in V. vulnificus and their regulation by transcription factors in response to various environmental signals. This expanded understanding of molecular pathogenesis would provide novel clues to develop an effective antivirulence therapy against V. vulnificus infection.
Topics: Animals; Humans; Vibrio vulnificus; Virulence Factors; Virulence; Transcription Factors; Biofilms
PubMed: 35753865
DOI: 10.1016/j.tim.2022.05.009 -
Euro Surveillance : Bulletin Europeen... Oct 2021Background spp. are aquatic bacteria that prefer warm seawater with moderate salinity. In humans, they can cause gastroenteritis, wound infections, and ear infections....
Background spp. are aquatic bacteria that prefer warm seawater with moderate salinity. In humans, they can cause gastroenteritis, wound infections, and ear infections. During the summers of 2018 and 2019, unprecedented high sea surface temperatures were recorded in the German Baltic Sea.AimWe aimed to describe the clinical course and microbiological characteristics of infections in Germany in 2018 and 2019.MethodsWe performed an observational retrospective multi-centre cohort study of patients diagnosed with domestically-acquired infections in Germany in 2018 and 2019. Demographic, clinical, and microbiological data were assessed, and isolates were subjected to whole genome sequencing and antimicrobial susceptibility testing.ResultsOf the 63 patients with infections, most contracted the virus between June and September, primarily in the Baltic Sea: 44 (70%) were male and the median age was 65 years (range: 2-93 years). Thirty-eight patients presented with wound infections, 16 with ear infections, six with gastroenteritis, two with pneumonia (after seawater aspiration) and one with primary septicaemia. The majority of infections were attributed to (non-O1/non-O139) (n = 30; 48%) or (n = 22; 38%). Phylogenetic analyses of 12 available isolates showed clusters of three identical strains of , which caused wound infections, suggesting that some clonal lines can spread across the Baltic Sea.ConclusionsDuring the summers of 2018 and 2019, severe heatwaves facilitated increased numbers of infections in Germany. Since climate change is likely to favour the proliferation of these bacteria, a further increase in -associated diseases is expected.
Topics: Aged; Cohort Studies; Germany; Humans; Male; Phylogeny; Retrospective Studies; Vibrio; Vibrio Infections
PubMed: 34651572
DOI: 10.2807/1560-7917.ES.2021.26.41.2002041