Vibrio Mimicus Research Articles

First Report of a Fatal Septicemia Case Caused by Vibrio metoecus: A Comprehensive Functional and Genomic Study

Abstract Background In recent years, we have witnessed an unprecedented increase in the incidence of vibriosis due to global warming. Vibrio metoecus is a recently described Vibrio cholerae-like species that has not been associated with septicemia death in humans. During follow-up of human vibriosis, we received a blood isolate from a patient with secondary septicemia who died a few hours after admission. Methods Phenotypic and genotypic methods failed to identify the isolate, which could only be identified by average nucleotide identity after genome sequencing. The isolate was subjected to in vitro and ex vivo assays, complemented by comparative genomics focused on the identification of unique genetic traits. Strains and genomes from the same and related species (V. cholerae and Vibrio mimicus) were used for analyses. Results The isolate was the only one able to resist and multiply in human serum. Its genome contained virulence genes shared with V. mimicus and/or V. cholerae, with those associated with sialic acid degradation within pathogenicity island 2 standing out. However, it also presented a unique gene cluster, flanked by a transposase gene, putatively related to surface polysaccharide pseudosialyzation. Conclusions We document the first case of death caused by septicemia due to V. metoecus and propose that the acquisition of surface pseudosialyzation genes explains the ability of certain isolates of this species to survive in blood. Our discovery underscores the urgent need to monitor and study newly emerging pathogenic species, as climate change may be facilitating their spread and increasing the risk of serious infections in humans.

Ferric uptake regulator (Fur) in Vibrio mimicus acts as an activator of citrate cycle and oxidative phosphorylation pathways, while enhancing virulence potential

Ferric uptake regulator (Fur) is a crucial bacterial regulator that controls the uptake of iron by bacteria, hence influencing their survival and pathogenicity. Vibrio mimicus is an epidemic pathogen that is harmful to aquatic animals and human health, with the characteristics of rapid onset and high mortality after infecting the fish. At present, the function and mechanism of Fur in V. mimicus are still unclear. In this study, the fur gene deletion strain and complementation strain of V. mimicus were constructed. Following fur deletion, proteomic analysis revealed that the abundance of 258 proteins was considerably up-regulated while the abundance of 307 proteins was dramatically down-regulated. The primary roles of these differentially expressed proteins were in a variety of pathways, including virulence, metabolism, enzymes, and so on. Among them, citrate cycle and oxidative phosphorylation were the main pathways affected by Fur. The activities of key enzymes in these two pathways were assessed. The results indicated a decrease in the activities of respiratory chain complexes II and IV, succinate dehydrogenase (SDH), and α-ketoglutarate dehydrogenase (α-KGDH) in the Δfur strain. Conversely, the activity of isocitrate dehydrogenase (NAD-IDH) was increased. Phenotypic characterization showed that the Δfur strain exhibited delayed growth, reduced motility, defective biofilm formation, decreased resistance to oxidative stress, increased adhesion, and decreased virulence. Besides, the LD50 of the Δfur strain was 31-fold higher than that of the WT strain. These results indicate that Fur serves as an activator for the citrate cycle and oxidative phosphorylation pathway in V. mimicus, and contributing to its virulence. Our findings enhance the understanding of the biological functions of Fur and lay the groundwork for further investigation into the regulatory mechanisms of Fur in V. mimicus.

RpoS sigma factor mediates adaptation and virulence in Vibrio mimicus

The alternative sigma factor RpoS functions as a regulator of stress and virulence response in numerous bacterial species. Vibrio mimicus is a critical opportunistic pathogen causing huge losses to aquaculture. However, the exact role of RpoS in V. mimicus remains unclear. In this study, rpoS deletion mutant of V. mimicus was constructed through allelic exchange and the phenotypic and transcriptional changes were investigated to determine the function of RpoS. The abilities of growth, motility, biofilm production, hemolytic activity and pathogenicity were significantly impaired in ΔrpoS strain. Stationary-phase cells of ΔrpoS strain showed lower tolerance to H2O2, heat, ethanol, and starvation stress than the wild-type strain. Transcriptome analyses revealed the involvement of rpoS in various cellular processes, notably bacterial-type flagellum synthesis and assembly, membrane synthesis and assembly and response to various stimuli. Phenotypic and RNA-seq analysis revealed that RpoS is required for biofilm formation, stress resistance, and pathogenicity in V. mimicus. Furthermore, β-galactosidase activity showed that rpoS is essential for optimal transcription of the flgK, fliA, cheA, mcpH mRNA. These results offer significant insight into the function and regulatory network of rpoS/RpoS, thereby improving our understanding and facilitating selection of molecular targets for future prevention strategies against V. mimicus.

Vibrio mimicus Lineage Carrying Cholera Toxin and Vibrio Pathogenicity Island, United States and China.

Vibrio mimicus bacteria have caused sporadic cases and outbreaks of cholera-like diarrhea throughout the world, but the association of lineages with such events is unexplored. Genomic analyses revealed V. mimicus lineages carrying the virulence factors cholera toxin and toxin coregulated pilus, one of which has persisted for decades in China and the United States.

Chemical and Microbiological Quality of Municipal Supply Water in Dhaka South Area, Bangladesh

This project aimed to find out the microbiological quality of municipal supply water in Dhaka South area and if the current regime of microbiological quality testing can determine the risk to public health from supply water satisfactorily. Water samples were collected from six different points of the water distribution network of Dhaka’s south locality, starting from the source (Shitalakhyariver, Narayanganj) to Jagannath University, Dhaka. The dominant taxonomic units were isolated using standard culture techniques, followed by biochemical identification, VITEK2 identification, and biofilm-forming potential of each isolate individually and co-cultured with other isolates. Presumptive identification of isolates from the Shitalakhya River revealed the presence of Citrobacter sp., Alcaligenes sp., and Pseudomonas putida. The sample from Saydabad Water Treatment Plant yielded Vibrio mimicus, Pseudomonas fluorescence, and Alcalimonas. The major aerobic bacteria in the water specimen from the community overhead tank included S aureus, Bacillus cereus, Micrococcus sp., Enterococcus sp., Lactococcus sp. Tap water revealed the presence of Escherichia coli, Lactococcus, Enterobacter, Shigella, Klebsiella, Pseudomonas, and Staphylococcus aureus, as well as anaerobic bacteria. Biochemical tests and VITEK2 yielded different results. Potential biofilm formers such as Klebsiella, E. coli, Enterococcus, Aerococcus, Enterobacter, and Cronobacter indicated quality deterioration potential inside the piped water supply system. Alteration in the major taxonomic units throughout the municipal water distribution network and the presence of opportunistic pathogens and biofilm-formers indicate the necessity for an updated water treatment, quality control, and in-line maintenance system.

Exploitation of multiple host-derived nutrients by the yellow catfish epidermal environment facilitates Vibrio mimicus to sustain infection potency and susceptibility

Infection with Vibrio mimicus in the Siluriformes has demonstrated a rapid and high infectivity and mortality rate, distinct from other hosts. Our earlier investigations identified necrosis, an inflammatory storm, and tissue remodeling as crucial pathological responses in yellow catfish (Pelteobagrus fulvidraco) infected with V. mimicus. The objective of this study was to further elucidate the impact linking these pathological responses within the host during V. mimicus infection. Employing metabolomics and transcriptomics, we uncovered infection-induced dense vacuolization of perimysium; Several genes related to nucleosidase and peptidase activities were significantly upregulated in the skin and muscles of infected fish. Concurrently, the translation processes of host cells were impaired. Further investigation revealed that V. mimicus completes its infection process by enhancing its metabolism, including the utilization of oligopeptides and nucleotides. The high susceptibility of yellow catfish to V. mimicus infection was associated with the composition of its body surface, which provided a microenvironment rich in various nucleotides such as dIMP, dAMP, deoxyguanosine, and ADP, in addition to several amino acids and peptides. Some of these metabolites significantly boost V. mimicus growth and motility, thus influencing its biological functions. Furthermore, we uncovered an elevated expression of gangliosides on the surface of yellow catfish, aiding V. mimicus adhesion and increasing its infection risk. Notably, we observed that the skin and muscles of yellow catfish were deficient in over 25 polyunsaturated fatty acids, such as Eicosapentaenoic acid, 12-oxo-ETE, and 13-Oxo-ODE. These substances play a role in anti-inflammatory mechanisms, possibly contributing to the immune dysregulation observed in yellow catfish. In summary, our study reveals a host immune deviation phenomenon that promotes bacterial colonization by increasing nutrient supply. It underscores the crucial factors rendering yellow catfish highly susceptible to V. mimicus, indicating that host nutritional sources not only enable the establishment and maintenance of infection within the host but also aid bacterial survival under immune pressure, ultimately completing its lifecycle.

Isolation and Identification of Vibrio Species from Different Types of Water Sources Along with Their Drug Susceptible Pattern

Abstract Background: Human activities are almost usually the cause of contaminated water supplies and places with large population densities and intensive land usage are particularly prone to pollution of drinking water sources. It is challenging to detoxify polluted water sources. Cholera is an acute form of diarrheal disease that plagued human civilization over the centuries. Vibrio spp., commonly found in aquatic environments, are the most common cause of bacterial gastroenteritis in the world, those may spread to humans through the ingestion of contaminated drinking water or exposure to seawater. Methods: In the present study, a total of 12 samples were collected from four types of water sources for the isolation of Vibrio spp. along with their drug-resistant pattern through conventional, biochemical, and antibiotic disc diffusion methods. Results: The samples were enriched into alkaline peptone water and then inoculated into culture media such as nutrient agar, MacConkey, and TCBs agar medium. After incubation for 24 h at 37°C on TCBS agar, yellow and green colonies were screened out for biochemical identification. Nonsucrose-fermenting Vibrio parahaemolyticus, Vibrio mimicus, and Vibrio vulnificus showed green colonies, and sucrose-fermenting Vibrio cholera and Vibrio alginolyticus showed yellow colonies on TCBS. The antibiotics ERY (15 μg), PCN (10 μg), CEX (30 μg), and VAN (30 μg) were completely resistant while the more effective antibiotics against Vibrio spp. were SXT (25 μg), CHL (30 μg), and GEN (30 μg). However, ciprofloxacin and nitrofurantoin showed moderate efficacy. Conclusion: To expand current knowledge on the occurrence, ecological niche, and persistence of potential human pathogenic Vibrio spp. in aquatic environments, the extensive laboratory experiment is required. To sum up, this kind of information is crucial for bringing attention to the existence of Vibrio spp. and enabling prompt implementation of preventive measures.

Synthesis and characterization of silver nanoparticles from Cocos nucifera L. male flowers: An investigation into their potent antibacterial and anticancer efficacy

The current research focused on the production of silver nanoparticles using dichloro methane-mediated Cocos nucifera male flower extract and their minimum inhibitory concentration against ten different bacterial pathogens. C. nucifera male flowers were extracted by 100% DCM, and the phytochemicals present in this extract were studied. These plant phytochemicals act as reducing agents to reduce the silver nitrate (AgNO3) to silver nanoparticles (AgNPs) which was confirmed by UV/Vis spectrophotometer, Fourier transform infra-red spectrum, X-ray diffraction analysis, and scanning electron microscopy. The 15 µL of silver nanoparticles was the minimum inhibitory concentration for Klebsiella pneumonia and Bacillus subtilis. The 20 µL of silver nanoparticles is the MIC for Pseudomonas aeruginosa, Vibrio harveyi, and Plesiomonas shigelloides. 30 µL of plant flower extract concentration highly inhibits the E. coli, Staphylococcus aureus, Salmonella paratyphi, Vibrio mimicus, and Vibrio alginolyticus bacterial pathogens. C. nucifera male flowers extract derived silver nanoparticles are highly stable and have high potential activity against MCF-7 Cell line.
 KEY WORDS: Cocos nucifera, Nanoparticles, Phytochemicals, Antimicrobials, Bacterial pathogens, MCF 7 Cell line
 Bull. Chem. Soc. Ethiop. 2024, 38(3), 715-724. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i3.13

Evaluation of antimicrobial, thrombolytic and cytotoxic activities of ethanol flower extract of Bauhinia acuminata

Background: To develop the herbal drug with the least side effects, there are superior opportunities to discover the medicinal and other biological properties. Natural products serve as sources of beneficial chemical molecules. For this study, Bauhinia acuminate (Family: Fabaceae) having some pharmacological activities was chosen. The present studies was designed for the antimicrobial, thrombolytic and cytotoxic activity of ethanolic flowers extract of Bauhinia acuminata. Methods: The antimicrobial effect of the extracts was evaluated by Disc-Diffusion Assay Method and the cytotoxic activity was determined by brine shrimp lethality test. The thrombolytic activities of the plant extracts were evaluated by a method using streptokinase as a reference standard. Results: The extract has mild antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, enteropathegenic Escherichia coli, Salmonella typhi, Vibrio mimicus. The zone of inhibition of the extract was measured comparing with standard Tetracycline. Thrombolytic activity of flowers of Bauhinia acuminata showed mild (14.57%) clot lysis while the standard streptokinase showed (90%). Having moderate cytotoxic activities, the mortality rate of brine shrimp was observed in increasing order with the increasing of concentration of extract. In the present study of the ethanol extract LC50=3.251 µg/ml and LC90=286.57 µg/ml. However, Standard control LC50=0.0036 µg/ml and LC90=0.75 µg/ml were found respectively. Conclusions: Through the studies, it can be concluded that the ethanolic extract of Bauhinia acuminata could be used in drug formulation or pharmaceutical application. Hence, the plant may further be explored for its various pharmacological activities.

Transcriptome reveals the role of the htpG gene in mediating antibiotic resistance through cell envelope modulation in Vibrio mimicus SCCF01.

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 htpG gene on antibiotic resistance in Vibrio mimicus. Through the creation of htpG gene deletion and complementation strains, we have uncovered the essential role of htpG in regulating the structural integrity of the bacterial cell envelope. Our transcriptomics analysis demonstrates that the deletion of htpG increases the sensitivity of V. mimicus 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 ΔhtpG 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 htpG-mediated resistance mechanisms, aiding in the development of antimicrobial agents. To our knowledge, this is the first effort to explore the relationship between htpG and drug resistance in bacteria.

Vibrio mimicus: A rare wound infection in a patient with neuroendocrine tumor of the humerus

Vibrio mimicus: A rare wound infection in a patient with neuroendocrine tumor of the humerus

Occurrence of virulence determinants in vibrio cholerae, vibrio mimicus, vibrio alginolyticus, and vibrio parahaemolyticus isolates from important water resources of Eastern Cape, South Africa

BackgroundVirulence determinants are crucial to the risk assessment of pathogens in an environment. This study investigated the presence of eleven key virulence-associated genes in Vibrio cholerae (n = 111) and Vibrio mimicus (n = 22) and eight virulence determinants in Vibrio alginolyticus (n = 65) and Vibrio parahaemolyticus (n = 17) isolated from six important water resources in Eastern Cape, South Africa, using PCR techniques. The multiple virulence gene indexes (MVGI) for sampling sites and isolates as well as hotspots for potential vibriosis outbreaks among sampling sites were determined statistically based on the comparison of MVGI.ResultThe PCR assay showed that all the V. cholerae isolates belong to non-O1/non-O139 serogroups. Of the isolates, Vibrio Cholera (84%), V. mimicus (73%), V. alginolyticus (91%) and V. parahaemolyticus (100%) isolates harboured at least one of the virulence-associated genes investigated. The virulence gene combinations detected in isolates varied at sampling site and across sites. Typical virulence-associated determinants of V. cholerae were detected in V. mimicus while that of V. parahaemolyticus were detected in V. alginolyticus. The isolates with the highest MVGI were recovered from three estuaries (Sunday river, Swartkopps river, buffalo river) and a freshwater resource (Lashinton river). The cumulative MVGI for V. cholerae, V. mimicus, V. alginolyticus and V. parahaemolyticus isolates were 0.34, 0.20, 0.45, and 0.40 respectively. The targeted Vibrio spp. in increasing order of the public health risk posed in our study areas based on the MVGI is V. alginolyticus > V. parahaemolyticus > V. cholerae > V. mimicus. Five (sites SR, PA5, PA6, EL4 and EL6) out of the seventeen sampling sites were detected as the hotspots for potential cholera-like infection and vibriosis outbreaks.ConclusionsOur findings suggest that humans having contact with water resources in our study areas are exposed to potential public health risks owing to the detection of virulent determinants in human pathogenic Vibrio spp. recovered from the water resources. The study affirms the relevancy of environmental Vibrio species to the epidemiology of vibriosis, cholera and cholera-like infections. Hence we suggest a monitoring program for human pathogenic Vibrio spp. in the environment most especially surface water that humans have contact with regularly.

Seafood-Associated Outbreak of ctx-Negative Vibrio mimicus Causing Cholera-Like Illness, Florida, USA.

Vibrio mimicus caused a seafood-associated outbreak in Florida, USA, in which 4 of 6 case-patients were hospitalized; 1 required intensive care for severe diarrhea. Strains were ctx-negative but carried genes for other virulence determinants (hemolysin, proteases, and types I-IV and VI secretion systems). Cholera toxin-negative bacterial strains can cause cholera-like disease.

Involvement of RpoN in regulating stress response, biofilm formation and virulence of Vibrio mimicus

RpoN, an alternative sigma factor, plays a crucial role in response to changes in environmental cues and pathogenicity. Vibrio mimicus, a serious pathogen in both fresh and seawater aquaculture industries, has garnered considerable attention. Nevertheless, reports of rpoN in V. mimicus remain extremely scarce. In this study, we constructed the rpoN-RNAi strain to investigate the role of rpoN in V. mimicus using phenotypic and RNA-seq analysis. The data indicated that rpoN positively regulated the resistance of V. mimicus to H2O2, ethanol and acid, while negatively regulating the resistance to alkali and heat, and had no influence on the resistance to NaCl. Over the period of 12 to 72 h, the biofilm formation ability of rpoN-RNAi strain was decreased by 0.29 to 0.84-fold compared to wild-type strain. Compared to wild strain, the siderophore production was decreased from 85.9% to 60.3% in rpoN-RNAi strain. Furthermore, the LD50 increased from 6.16 × 105 to 3.92 × 106 CFU/mL in Macrobrachium nipponense through artificial infection test after rpoN silencing. Transcriptome analysis revealed that several well-known virulence-related genes were down-regulated in rpoN-RNAi strain. These genes included the type VI secretion system genes (vipB, vipA, impI, and vasA), type IV pilus assembly protein (flpB-G), outer membrane proteins (ompU and ompA), and hemolysin. Additionally, stress-protective genes encoding heat shock protein, oxidoreductase, aldehyde dehydrogenase, quorum sensing system, etc., were also down-regulated by rpoN-RNAi. Transcriptome analysis was consistent with the observed phenotypes in rpoN-RNAi strain. These results revealed that rpoN is a critical determinant for bacterial fitness and pathogenicity, laying the groundwork for further characterization of RpoN regulatory networks.

Lc-pPG-612-OmpU-CTB: A promising oral vaccine for protecting Carassius auratus against Vibrio mimicus infection.

Vibrio mimicus (V. mimicus) is known to cause severe bacterial diseases with high mortality rates in fish, resulting in significant economic losses in the global aquaculture industry. Therefore, the objective of this study was to develop a safe and effective vaccine for protecting Carassius auratus (C. auratus) against V. mimicus infection. Recombinant Lactobacillus casei (L. casei) strains, Lc-pPG-612-OmpU and Lc-pPG-612-OmpU-CTB (surface-displayed), were constructed using a L. casei strain (ATCC 393) as an antigen delivery carrier and the cholera toxin B subunit (CTB) as an adjuvant. The two recombinant strains of L. casei were administered to C. auratus via oral immunization, and the protective efficacy of the oral vaccines was assessed. The results demonstrated that oral immunization with the two strains significantly increased the levels of nonspecific immune indicators in C. auratus, including alkaline phosphatase (AKP), lysozyme (LYS), acid phosphatase (ACP), complement 3 (C3), complement 4 (C4), lectin, and superoxide dismutase (SOD). Moreover, the experiment groups exhibited significant increases in specific immunoglobulin M (IgM) antibodies against OmpU, as well as the transcription of immune-related genes (ie., IL-1β, TNF-α, IL-10, and TGF-β), when compared to the control groups. Following infection of C. auratus with V. mimicus, the mortality rate of the recombinant L. casei-treated fish was observed to be lower compared to the control group. This finding suggests that recombinant L. casei demonstrates effective protection against V. mimicus infection in C. auratus. Furthermore, the addition of the immune adjuvant CTB was found to induce a more robust adaptive and innate immune response in C. auratus, resulting in reduced mortality after infection with V. mimicus.

Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa.

The current study determines the density of Vibrio spp. and isolates V. cholerae and Vibrio mimicus from fish-anatomical-sites, prawn, crab and mussel samples recovered from fish markets, freshwater and brackish water. Virulence and antibiotic resistance profiling of isolates were carried out using standard molecular and microbiology techniques. Vibrio spp. was detected in more than 90% of samples [134/144] and its density was significantly more in fish than in other samples. Vibrio. cholerae and V. mimicus were isolated in at least one sample of each sample type with higher isolation frequency in fish samples. All the V. cholerae isolates belong to non-O1/non-O139 serogroup. One or more V. cholerae isolates exhibited intermediate or resistance against each of the eighteen panels of antibiotics used but 100% of the V. mimicus were susceptible to amikacin, gentamycin and chloramphenicol. Vibrio cholerae exhibited relatively high resistance against polymyxin, ampicillin and amoxicillin/clavulanate while V. mimicus isolates exhibited relatively high resistance against nitrofurantoin, ampicillin and polymixin. The multiple-antibiotic-resistance-index [MARI] for isolates ranges between 0 and 0.67 and 48% of the isolates have MARI that is >0.2 while 55% of the isolates exhibit MultiDrug Resistance Phenotypes. The percentage detection of acc, ant, drf18, sul1, mcr-1, blasvh, blaoxa, blatem, blaoxa48, gyrA, gyrB and parC resistance-associated genes were 2%, 9%, 14%, 7%, 2%, 25%, 7%, 2%, 2%, 32%, 25% and 27% respectively while that for virulence-associated genes in increasing other was ace [2%], tcp [11%], vpi [16%], ompU [34%], toxR [43%], rtxC [70%], rtxA [73%] and hyla [77%]. The study confirmed the potential of environmental non-O1/non-O139 V. cholerae and V. mimicus to cause cholera-like infection and other vibriosis which could be difficult to manage with commonly recommended antibiotics. Thus, regular monitoring of the environment to create necessary awareness for this kind of pathogens is important in the interest of public health.

Unraveling extracellular protein signatures to enhance live attenuated vaccine development through type II secretion system disruption in Vibriomimicus

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.

Distribution, Prevalence, and Antibiotic Susceptibility Profiles of Infectious Noncholera Vibrio Species in Malaysia.

The noncholera Vibrio spp. which cause vibriosis are abundantly found in our water ecosystem. These bacteria could negatively affect both humans and animals. To date, there is a paucity of information available on the existence and pathogenicity of this particular noncholera Vibrio spp. in Malaysia in comparison to their counterpart, Vibrio cholera. In this study, we extracted retrospective data from Malaysian surveillance database. Analysis was carried out using WHONET software focusing noncholera Vibrio spp. including Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio fluvialis, Vibrio alginolyticus, Vibrio hollisae (Grimontia hollisae), Vibrio mimicus, Vibrio metschnikovii, and Vibrio furnissii. Here, we report the first distribution and prevalence of these species isolated in Malaysia together with the antibiotic sensitivity profile based on the species. We found that V. parahaemolyticus is the predominant species isolated in Malaysia. Noticeably, across the study period, V. fluvialis is becoming more prevalent, as compared to V. parahaemolyticus. In addition, this study also reports the first isolation of pathogenic V. furnissii from stool in Malaysia. These data represent an important step toward understanding the potential emergence of noncholera Vibrio spp. outbreaks.

Integrated bioinformatics identifies key mediators in cytokine storm and tissue remodeling during Vibrio mimicus infection in yellow catfish (Pelteobagrus fulvidraco).

The pathogenesis of Vibrio mimicus infection in yellow catfish (Pelteobagrus fulvidraco) remains poorly understood, particularly regarding the impact of infection with the pathogen on primary target organs such as the skin and muscle. In this study, we aim to analyze the pathological intricacies of the skin and muscle of yellow catfish after being infected with V. mimicus using a 1/10 LC50 seven-day post-infection model. Furthermore, we have utilized integrated bioinformatics to comprehensively elucidate the regulatory mechanisms and identify the key regulatory genes implicated in this phenomenon. Our histopathological examination revealed significant pathological changes in the skin and muscle, characterized by necrosis and inflammation. Moreover, tissue remodeling occurred, with perimysium degeneration and lesion invasion into the muscle along the endomysium, accompanied by a transformation of type I collagen into a mixture of type I and type III collagens in the perimysium and muscle bundles. Our eukaryotic transcriptomic and 4D label-free analyses demonstrated a predominantly immune pathway response in both the skin and muscle, with downregulation observed in several cell signaling pathways that focused on focal adhesion-dominated cell signaling pathways. The upregulated genes included interleukins (IL)-1 and -6, chemokines, and matrix metallopeptidases (mmp)-9 and -13, while several genes were significantly downregulated, including col1a and col1a1a. Further analysis revealed that these pathways were differentially regulated, with mmp-9 and mmp-13 acting as the potential core regulators of cytokine and tissue remodeling pathways. Upregulation of NF-κB1 and FOSL-1 induced by IL-17C and Nox 1/2-based NADPH oxidase may have held matrix metallopeptidase and cytokine-related genes. Also, we confirmed these relevant regulatory pathways by qPCR and ELISA in expanded samples. Our findings unequivocally illustrate the occurrence of a cytokine storm and tissue remodeling, mediated by interleukins, chemokines, and MMPs, in the surface of yellow catfish infected with V. mimicus. Additionally, we unveil the potential bidirectional regulatory role of MMP-9 and MMP-13. These results provide novel perspectives on the intricate immune response to V. mimicus infection in yellow catfish and highlight potential targets for developing therapies.

In vitro pharmacological activities of methanol extract of Acmella oleracea leaves: A variety grown in Dhaka, Bangladesh

is known as toothache plant belongs to the family of Asteraceae. It is treated as a medicinal remedy like tuberculosis, illness, cough, rheumatism, and illness. This study was concentrated on the antioxidant, cytotoxic, antimicrobial & thrombolytic activities of methanol extract of leaves using in vitro model. The antioxidant activity was estimated as trolox equivalent antioxidant capacity utilizing the DPPH and reducing power tests. The plant extract was tested for its cytotoxic action using a brine shrimp lethality bioassay, thrombolytic activity using clot disruption, and antibacterial activity using a disc diffusion assay technique against four distinct gram-positive also gram-negative bacteria. ICvalue of standard ascorbic acid for DPPH was 7.8µg/ml and the IC50 of the methanol extract of leaves was 198.34µg/ml that was moderate effect at all compare with ascorbic acid. Thrombolytic assay of Streptokinase as a positive control showed 88.49% where the extract shows 18.69% lytic activity shows the assay. In this study, the sample of LC results of cytotoxicity assay was 1.431 µg/mL which can be treated as less activity. Moreover, the extracts showed low to moderate antibacterial activity against both gram-negative and gram-positive bacterial stains (zone of inhibition-10-26 mm). Vibrio Mimicus bacteria stains exhibited the highest level of activity, with a range of 23 for the diameter of the growth inhibition zone. The current review shows leaf extracts of may be used as a source of antioxidant and thrombolytic activity, as well as a significant source of antibacterial and anticancer substances. Further research is required to evaluate in-vivo the pharmacological activity of leaves in order to identify the essential metabolites and potential mechanisms.