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Microorganisms Jan 2021is an emerging pathogen, mainly associated with contaminated seafood consumption. However, little is known about its evolution, biodiversity, and pathogenic potential....
is an emerging pathogen, mainly associated with contaminated seafood consumption. However, little is known about its evolution, biodiversity, and pathogenic potential. This study analyzes the pan-, core, and accessory genomes of nine strains. The core genome yielded 2424 genes in chromosome I (ChI) and 822 genes in chromosome II (ChII), with an accessory genome comprising an average of 10.9% of the whole genome for ChI and 29% for ChII. Core genome phylogenetic trees were obtained, and ATCC-33654 strain was the closest to the outgroup in both chromosomes. Additionally, a phylogenetic study of eight conserved genes (Z, A, B, , A, A, B, and H), including , , , and , clearly showed clade differentiation. The main virulence genes found in ChI corresponded with type I secretion proteins, extracellular components, flagellar proteins, and potential regulators, while, in ChII, the main categories were type-I secretion proteins, chemotaxis proteins, and antibiotic resistance proteins. The accessory genome was characterized by the presence of mobile elements and toxin encoding genes in both chromosomes. Based on the genome atlas, it was possible to characterize differential regions between strains. The pan-genome of encompassed 3539 genes for ChI and 2355 genes for ChII. These results give us an insight into the virulence and gene content of , as well as constitute the first approach to its diversity.
PubMed: 33477474
DOI: 10.3390/microorganisms9010191 -
Nature Microbiology Dec 2020The bacterial flagellum is the prototypical protein nanomachine and comprises a rotating helical propeller attached to a membrane-embedded motor complex. The motor...
The bacterial flagellum is the prototypical protein nanomachine and comprises a rotating helical propeller attached to a membrane-embedded motor complex. The motor consists of a central rotor surrounded by stator units that couple ion flow across the cytoplasmic membrane to generate torque. Here, we present the structures of the stator complexes from Clostridium sporogenes, Bacillus subtilis and Vibrio mimicus, allowing interpretation of the extensive body of data on stator mechanism. The structures reveal an unexpected asymmetric AB subunit assembly where the five A subunits enclose the two B subunits. Comparison to structures of other ion-driven motors indicates that this AB architecture is fundamental to bacterial systems that couple energy from ion flow to generate mechanical work at a distance and suggests that such events involve rotation in the motor structures.
Topics: Bacillus subtilis; Bacterial Proteins; Clostridium; Flagella; Molecular Motor Proteins; Rotation; Vibrio mimicus
PubMed: 32929189
DOI: 10.1038/s41564-020-0788-8 -
International Journal of Microbiology 2020The aim of this study was to characterise species of water samples collected from taps, boreholes, and dams in the North West province, South Africa, and assess...
The aim of this study was to characterise species of water samples collected from taps, boreholes, and dams in the North West province, South Africa, and assess biocontrol potentials of their bacteriophages. Fifty-seven putative isolates were obtained on thiosulfate-citrate-bile-salt-sucrose agar and identified using biochemical tests and species-specific PCRs. Isolates were further characterised based on the presence of virulence factors, susceptibility to eleven antibiotics, and biofilm formation potentials. Twenty-two (38.60%) isolates were confirmed as species, comprising (45.5%, = 10), (22.7%, = 5), (13.6%, = 3), (9.1%, = 2), and (9.1%, = 2). Three of the six virulent genes screened were positively amplified; four possessed the (18.18%) and (18.18%) genes, while the gene was harboured by 3 V. (13.64%) and one (4.55%) isolate. Isolates revealed high levels of resistance to cephalothin (95.45%), ampicillin (77.27%), and streptomycin (40.91%), while lower resistances (4.55%-27.27%) were recorded for other antimicrobials. Sixteen (72.7%) isolates displayed multiple antibiotic-resistant properties. Cluster analysis of antibiotic resistance revealed a closer relationship between isolates from different sampling sites. The species displayed biofilm formation potentials at 37°C (63.6, = 14), 35°C (50%, = 11), and 25°C (36.4%, = 8). Two phages isolated in this study (vB_VpM_SA3V and vB_VcM_SA3V) were classified as belonging to the family Myoviridae based on electron microscopy. These were able to lyse multidrug-resistant and strains. These findings not only indicate the presence of antibiotic-resistant virulent species from dam, borehole, and tap water samples that could pose a health risk to humans who either come in contact with or consume water but also present these lytic phages as alternative agents that can be exploited for biological control of these pathogenic strains.
PubMed: 32831847
DOI: 10.1155/2020/8863370 -
Frontiers in Physiology 2019A feeding trial was carried out to evaluate the effects of substitution of fishmeal (FM) by dietary poultry by-product meal, fermented by and on growth, intestinal...
A feeding trial was carried out to evaluate the effects of substitution of fishmeal (FM) by dietary poultry by-product meal, fermented by and on growth, intestinal health, microbial composition, immune related cytokines and disease resistance of freshwater crayfish, marron () against Two isonitrogenous and isocaloric diets were formulated by replacing FM protein with fermented poultry by-product meal (FPBM) protein at 0% (Control) and 75% (FPBM), and fed marron for 70 days. The results indicated no significant difference ( > 0.05) in final body weights between two groups of marron, whilst intestinal microvilli number per fold was increased in marron fed FPBM than the control. The 16S rRNA sequences revealed an increased number of and , and decreased number of at genus level in the distal intestine of marron fed FPBM. Marron fed FPBM showed up-regulated expression of IL-8, IL-10, and IL-17F genes in the distal intestine. Significantly ( < 0.05) increased lysozyme and phagocytic activity, and higher survival was found in marron fed FPBM following a bacterial challenge with . Therefore, it is concluded that FPBM is beneficial to marron in terms of microbial community, immune-related cytokines and disease resistance against
PubMed: 32082185
DOI: 10.3389/fphys.2019.01635 -
Virulence Dec 2020is a foodborne pathogen, which is widely distributed in the aquatic environment. Moreover, it is often involved in aquatic animal diseases. In recent years, is an...
is a foodborne pathogen, which is widely distributed in the aquatic environment. Moreover, it is often involved in aquatic animal diseases. In recent years, is an emerging pathogen in some species of Siluriformes. The strain SCCF01 was isolated from yellow catfish (). In this study, we aimed to perform genomic analysis of strain SCCF01 to identify genetic features and evolutionary relationships. Information on gene function and classification was obtained by functional annotation, and circular graph of strain SCCF01 genome, which was created by Circos v0.64. Information on virulence genes (adhesion, flagellum system, exotoxin, and secretory system, etc.) was obtained by virulence genes annotation. Genome element prediction showed that most of the mobile elements were distributed in chromosome I. Therefore, chromosome I of SCCF01 genome has more plasticity than chromosome II and might be larger in size. Genomic linear relationship between the strain of s and strain SCCF01 was analyzed by linear pairwise comparison but was unable to determine the relationship. Gene family analysis predicted that the evolutionary direction of strain SCCF01 was: clinical strain → environmental strain → SCCF01 strain. Phylogenetic analysis showed that the strain SCCF01 was more closely related to environmental strains. According to gene family analysis and phylogenetic analysis, we speculated that strain SCCF01 has probably diverged from environmental strains.
Topics: Animals; Bacterial Adhesion; Catfishes; Exotoxins; Flagella; Fresh Water; Genes, Bacterial; Genomics; Interspersed Repetitive Sequences; Phylogeny; Vibrio mimicus; Virulence; Virulence Factors
PubMed: 31826705
DOI: 10.1080/21505594.2019.1702797 -
Scientific Reports Nov 2019A potential mechanism for the global distribution of waterborne pathogens is through carriage by the migratory waterbirds. However, this mode of transmission has yet...
A potential mechanism for the global distribution of waterborne pathogens is through carriage by the migratory waterbirds. However, this mode of transmission has yet been confirmed epidemiologically. Here, we conducted whole genome sequencing of Vibrio spp. collected from waterbirds, sediments, and mollusks in the estuary of the Liaohe River in China to investigate this transmission mode. We found that a V. parahaemolyticus strain isolated from a waterbird was clonally related to the other V. parahaemolyticus strains obtained from the sediments and mollusks, and three V. mimicus strains isolated from bird feces were genomically related to those found in the mollusks and upstream groundwater, suggesting that the bird-carried Vibrio strains were acquired through the direct predation of the local mollusks. Surprisingly, two bird-carried V. parahaemolyticus strains belonging to the same clone were identified in Panjin and Shanghai, which are over 1,150 km apart, and another two were found at two locations 50 km apart, further supporting that waterbirds are capable of carrying and disseminating these pathogens over long distances. Our results provide the first evidence of direct transmission from mollusks to waterbirds and confirm that waterbirds act as disseminating vehicles of waterborne pathogens. Effective surveillance of migratory waterbirds along their routes will be valuable for predicting future epidemics of infectious diseases.
Topics: Animal Migration; Animals; Birds; Fisheries; Food Contamination; Genome, Bacterial; Genomics; Geography; Phylogeny; Phylogeography; Public Health Surveillance; Rivers; Vibrio; Vibrio Infections
PubMed: 31704994
DOI: 10.1038/s41598-019-52791-5 -
PeerJ 2019This study aimed to investigate the effects of as a dietary probiotic supplement in fishmeal based diet on growth, gut microbiota and immune performance of marron ()....
This study aimed to investigate the effects of as a dietary probiotic supplement in fishmeal based diet on growth, gut microbiota and immune performance of marron (). Marron were randomly distributed into two different treatment groups, control and probiotic fed group. After 42 days of feeding trial, the results revealed a significant ( < 0.05) increase in growth due to increase in number of moults in marron fed probiotics. The probiotic diet also significantly enhanced the total haemocyte counts (THC), lysozyme activity in the haemolymph and protein content of the tail muscle in marron. Compared to control, the 16S rRNA sequences data demonstrated an enrichment of bacterial diversity in the probiotic fed marron where significant increase of abundance was observed. The abundance for crayfish pathogen and were found to be significantly reduced post feeding with probiotic diet. Predicted metabolic pathway revealed an increased activity for the metabolism and absorption of carbohydrate, degradation of amino acid, fatty acid and toxic compounds, and biosynthesis of secondary metabolites. supplementation also significantly modulated the expression level of immune-responsive genes of marron post challenged with . The overall results suggest that could be used as dietary probiotic supplement in marron aquaculture.
PubMed: 31523510
DOI: 10.7717/peerj.7553 -
Applied and Environmental Microbiology Feb 2019Atypical El Tor strains of O1 harboring variant genes of cholera toxin (CT) have gradually become a major cause of recent cholera epidemics. occasionally produces CT,...
Atypical El Tor strains of O1 harboring variant genes of cholera toxin (CT) have gradually become a major cause of recent cholera epidemics. occasionally produces CT, encoded by on CTXФ genome; toxin-coregulated pilus (TCP), a major intestinal colonization factor; and also the CTXФ-specific receptor. This study carried out extensive molecular characterization of CTXФ and ToxT regulon in -positive () strains (i.e., strains containing ) isolated from the Bengal coast. Southern hybridization, PCR, and DNA sequencing of virulence-related genes revealed the presence of an El Tor type CTX prophage (CTX) carrying a novel , tandem copies of environmental type pre-CTX prophage (pre-CTX), and RS1 elements, which were organized as an RS1-CTX-RS1-pre-CTX-pre-CTX array. Additionally, novel variants of and , respectively, showing phylogenetic lineage to a clade of non-O1 and to a clade of non-O139, were identified. The strains lacked the RTX (repeat in toxin) and TLC (toxin-linked cryptic) elements and lacked seventh-pandemic islands of the El Tor strains but contained five heptamer (TTTTGAT) repeats in promoter region similar to those seen with some classical strains of O1. Pulsed-field gel electrophoresis (PFGE) analysis showed that all the strains were clonally related. However, their CT production and toxigenicity characteristics were variable, which could be explainable by differential transcription of virulence genes along with the ToxR regulon. Taken together, our findings strongly suggest that environmental strains act as a potential reservoir of atypical virulence factors, including variant CT and ToxT regulons, and may contribute to the evolution of hybrid strains. Natural diversification of CTXФ and genes certainly influences disease severity and shifting patterns in major etiological agents of cholera, e.g., the overwhelming emergence of hybrid El Tor variants, replacing the prototype El Tor strains of This report, showing the occurrence of CTX comprising a novel variant of in , points out a previously unnoticed evolutionary event that is independent of the evolutionary event associated with the El Tor strains of Identification and cluster analysis of the newly discovered alleles of and suggest their horizontal transfer from an uncommon clone of The genomic contents of ToxT regulon and of tandemly arranged multiple pre-CTXФ and of a CTXФ in probably act as salient raw materials that induce natural recombination among the hallmark virulence genes of hybrid strains. This report provides valuable information to enrich our knowledge on the evolution of new variant CT and ToxT regulons.
Topics: Bacterial Proteins; Cholera; Cholera Toxin; Environmental Microbiology; Evolution, Molecular; Genetic Variation; Humans; Phylogeny; Regulon; Vibrio cholerae O1; Vibrio mimicus; Virulence Factors
PubMed: 30446560
DOI: 10.1128/AEM.01977-18 -
Biomedicines Jul 2016is a member of the Arecaceae family and a common plant in the Southeast Asian region. This plant has been reported as an anti-microbial agent in recent years. Thus, we...
BACKGROUND
is a member of the Arecaceae family and a common plant in the Southeast Asian region. This plant has been reported as an anti-microbial agent in recent years. Thus, we aimed to find out the MIC (minimum inhibitory concentration) against different pathogenic microorganism.
METHODS
The leaves of were extracted and fractioned using different reagents (chloroform, -hexane and carbon tetrachloride). Disc diffusion method was implemented for the assessment of in vitro anti-microbial potency (500 and 250 µg/disc).
RESULT
The entire fraction showed good effect (with the zone of inhibition 19-25 mm) against both gram positive (, , , ) and gram negative (, , , ) bacterial pathogens and fungal strains (, ). The plants also possess effective free radical scavenging potency with an IC of 130.32 µg/mL.
CONCLUSION
This finding reflects a link between the presence of anti-oxidative material and a substantial anti-microbial activity, and substantiates all previous claims against .
PubMed: 28536384
DOI: 10.3390/biomedicines4030017 -
PloS One 2016Vibrio mimicus is a pathogen that causes ascites disease in fish. We have previously demonstrated that the outer membrane protein U (OmpU) is an important adhesin in V....
Vibrio mimicus is a pathogen that causes ascites disease in fish. We have previously demonstrated that the outer membrane protein U (OmpU) is an important adhesin in V. mimicus. Here eight specific OmpU-binding phage clones, which presented three different OmpU-binding peptides (designated P1, P2, P3), were screened from a commercially available phage displayed 12-mer peptide library using rOmpU protein as target. Then, synthetic OmpU-binding peptides were measured for their adhesion antagonistic activity and binding affinity via adhesion inhibition test and non-competitive ELISA, respectively. The results showed that after co-incubated with the mixture of rOmpU and P3, visible green fluorescence could be observed on the epithelioma papulosum cyprinidi (EPC) cells surface; while the EPC cells co-incubated with the mixture of rOmpU and P1/P2 exhibited little green fluorescence. The average adhesion number of V. mimicus 04-14 isolate before and after treatment with peptide was 21.4 ± 1.5, 20.8 ± 0.8 (irrelevant peptide), 20.2 ± 0.5 (P3), 5.1 ± 0.7 (P1) and 3.4 ± 0.8 (P2), respectively. There was a significant decrease in the adhesive level of 04-14 isolate treated with P1/ P2 compared to the untreated isolate (p<0.01). The affinity constants of P1 and P2 were (6.17 ± 0.19) × 108 L/mol and (1.24 ± 0.56) × 109 L/mol, respectively. Furthermore, protective effects of P1 and P2 on grass carps challenged with V. mimicus were preliminary detected. It was found there was delayed death of fish in the groups treated with P1/P2, and the survival rate of challenged fish improved with the increase of the dose of adhesion antagonistic peptide. Taken together, two novel OmpU-binding peptides, which possessed adhesion antagonistic activity, high affinity and a certain degree of antibacterial activity against V. mimicus, were screened and identified.
Topics: Adhesins, Bacterial; Animals; Anti-Bacterial Agents; Bacterial Adhesion; Carps; Cell Line; Fish Diseases; Fishes; Peptide Library; Peptides; Vibrio mimicus
PubMed: 27832083
DOI: 10.1371/journal.pone.0165092