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Antibiotics (Basel, Switzerland) Mar 2021Antimicrobial and multidrug-resistant bacteria are a major problem worldwide and, consequently, the surveillance of antibiotic-resistant bacteria and assessment of the...
Antimicrobial and multidrug-resistant bacteria are a major problem worldwide and, consequently, the surveillance of antibiotic-resistant bacteria and assessment of the dissemination routes are essential. We hypothesized that migratory birds, coming from various environments, would carry more numerous strains than sedentary species, with increased risk to be passed to their contacts or environment in habitats they transit or nest in. Similarly, we presumed that strains from migratory birds will show multidrug resistance. A total of 170 oral and rectal swabs were collected from wild birds captured in different locations of the Danube Delta (Malic, Sfantu-Gheorghe, Letea Forest) and processed using standardized selective media. strains were confirmed by serology and molecular methods and, subsequently, their susceptibility was evaluated. The prevalence of species by host species, habitat type, and location was interpreted. The isolated species were identified as 14.33%, 13.33% 12% 17.33%, 10.88% with and (16%) also being prevalent. Of the 76 spp. isolates, 18.42% were resistant towards at least three antimicrobials, and 81.57% demonstrated a multidrug resistance phenotype, including mainly penicillins, aminoglycosides, and macrolides. The results of the present study indicate higher numbers of strains in migratory (74.66%) than in sedentary birds (25.33%), confirming our hypothesis. Furthermore, the increased pathogenicity of spp. strains, isolated from wild migratory and sedentary birds, was confirmed by their increased multiple antibiotic resistance (MAR) index (0.09-0.81).
PubMed: 33809945
DOI: 10.3390/antibiotics10030333 -
Modulation of Vibrio mimicus hemolysin through limited proteolysis by an endogenous metalloprotease.The FEBS Journal Feb 2009Vibrio mimicus is a causative agent of human gastroenteritis and food poisoning, and this species produces an enterotoxic hemolysin (V. mimicus hemolysin) as a virulence...
Vibrio mimicus is a causative agent of human gastroenteritis and food poisoning, and this species produces an enterotoxic hemolysin (V. mimicus hemolysin) as a virulence determinant. Vibrio mimicus hemolysin is secreted as an 80 kDa precursor, which is later converted to the 66 kDa mature toxin through removal of an N-terminal propeptide via cleavage of the Arg151-Ser152 bond. In this article, we investigate the role of the endogenous metalloprotease (V. mimicus protease) in the maturation of V. mimicus hemolysin. In vitro experiments using purified proteins showed that, although it activated the precursor at the early stage via cleavage of the Asn157-Val158 bond, V. mimicus protease finally converted the activated and physiologically maturated toxin to a 51 kDa protein through removal of the C-terminal polypeptide. This 51 kDa derivative was unable to lyse erythrocytes because of its inability to bind to the erythrocyte membrane. Vibrio mimicus protease-negative strains were found to produce high levels of V. mimicus hemolysin at the logarithmic phase of bacterial growth and maintained high hemolytic activity even at the stationary phase. These findings indicate that, although it is not directly related to toxin maturation in vivo, V. mimicus protease can modulate the activity of V. mimicus hemolysin and/or its precursor through limited proteolysis.
Topics: Bacterial Proteins; Hemolysin Proteins; Metalloproteases; Molecular Weight; Protein Binding; Vibrio mimicus
PubMed: 19143841
DOI: 10.1111/j.1742-4658.2008.06827.x -
Applied and Environmental Microbiology Apr 2021By characterizing the trajectories of antibiotic resistance gene transfer in bacterial communities such as the gut microbiome, we will better understand the factors that...
By characterizing the trajectories of antibiotic resistance gene transfer in bacterial communities such as the gut microbiome, we will better understand the factors that influence this spread of resistance. Our aim was to investigate the host network of a multidrug resistance broad-host-range plasmid in the culturable gut microbiome of zebrafish. This was done through and conjugation experiments with as the donor of the plasmid pB10:: When this donor was mixed with the extracted gut microbiome, only transconjugants of were detected. In separate matings between the same donor and four prominent isolates from the gut microbiome, the plasmid transferred to two of these four isolates, and , but not to and When these and transconjugants were the donors in matings with the same four isolates, the plasmid now also transferred from to was unable to donate the plasmid, and was unable to acquire it. Finally, when the donor was added to zebrafish through their food, plasmid transfer was observed in the gut, but only to , a rare member of the gut microbiome. This work shows that the success of plasmid-mediated antibiotic resistance spread in a gut microbiome depends on the donor-recipient species combinations and therefore their spatial arrangement. It also suggests that rare gut microbiome members should not be ignored as potential reservoirs of multidrug resistance plasmids from food. To understand how antibiotic resistance plasmids end up in human pathogens, it is crucial to learn how, where, and when they are transferred and maintained in members of bacterial communities such as the gut microbiome. To gain insight into the network of plasmid-mediated antibiotic resistance sharing in the gut microbiome, we investigated the transferability and maintenance of a multidrug resistance plasmid among the culturable bacteria of the zebrafish gut. We show that the success of plasmid-mediated antibiotic resistance spread in a gut microbiome can depend on which species are involved, as some are important nodes in the plasmid-host network and others are dead ends. Our findings also suggest that rare gut microbiome members should not be ignored as potential reservoirs of multidrug resistance plasmids from food.
Topics: Animals; Bacteria; Drug Resistance, Multiple, Bacterial; Female; Gastrointestinal Microbiome; Male; Plasmids; Zebrafish
PubMed: 33637574
DOI: 10.1128/AEM.02735-20 -
Frontiers in Microbiology 2022The potentially pathogenic species of the genus pose a threat to both humans and animals, creating medical burdens and economic losses to the mariculture industry....
The potentially pathogenic species of the genus pose a threat to both humans and animals, creating medical burdens and economic losses to the mariculture industry. Improvements in surveillance and diagnosis are needed to successfully manage vibriosis outbreaks. Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) can provide rapid diagnosis and has been widely used in the identification of spp. The main weakness of this technology is the limited number of strains and species of in the existing commercial database. Here, we develop a new in-house database named PVBase containing 790 main spectra projections (MSP) of ten species that come from various regions of China and include abundant clinical and environmental strains. PVBase was validated through a blind test of 65 strains. The identification accuracy and scoring of strains was greatly improved through the addition of PVBase. Identification accuracy increased from 73.4 to 100%. The number of strains with identification scores above 2.2 increased from 53.1% to 96.9% and 53.1% of strains had an identification score above 2.59. Moreover, perfect discrimination was obtained when using all of the MSPs created for the species, even for very closely related species such as , , and or , , and . In addition, we used phyloproteomic analysis to study whether there are differences in protein fingerprints of different regions or pathogenic strains. We found that MSP characteristics of species were not related to their region or source. With the construction of PVBase, the identification efficiency of potentially pathogenic species has been greatly improved, which is an important advance for epidemic prevention and control, and aquaculture disease detection.
PubMed: 35656002
DOI: 10.3389/fmicb.2022.872825 -
MSphere Aug 2021Vibrio parahaemolyticus is a marine Gram-negative bacterium that is a leading cause of seafood-borne gastroenteritis. Pandemic strains of V. parahaemolyticus rely on a...
Vibrio parahaemolyticus is a marine Gram-negative bacterium that is a leading cause of seafood-borne gastroenteritis. Pandemic strains of V. parahaemolyticus rely on a specialized protein secretion machinery known as the type III secretion system 2 (T3SS2) to cause disease. The T3SS2 mediates the delivery of effector proteins into the cytosol of infected cells, where they subvert multiple cellular pathways. Here, we identify a new T3SS2 effector protein encoded by VPA1328 (VP_RS21530) in V. parahaemolyticus RIMD2210633. Bioinformatic analysis revealed that VPA1328 is part of a larger family of uncharacterized T3SS effector proteins with homology to the VopG effector protein in Vibrio cholerae AM-19226. These VopG-like proteins are found in many but not all T3SS2 gene clusters and are distributed among diverse species, including V. parahaemolyticus, V. cholerae, V. mimicus, and V. diabolicus and also in Shewanella baltica. Structure-based prediction analyses uncovered the presence of a conserved C-terminal kinase domain in VopG orthologs, similar to the serine/threonine kinase domain found in the NleH family of T3SS effector proteins. However, in contrast to NleH effector proteins, in tissue culture-based infections, VopG did not impede host cell death or suppress interleukin 8 (IL-8) secretion, suggesting a yet undefined role for VopG during V. parahaemolyticus infection. Collectively, our work reveals that VopG effector proteins, a new family of likely serine/threonine kinases, is widely distributed in the T3SS2 effector armamentarium among marine bacteria. Vibrio parahaemolyticus is the leading bacterial cause of seafood-borne gastroenteritis worldwide. The pathogen relies on a type III secretion system to deliver a variety of effector proteins into the cytosol of infected cells to subvert cellular function. In this study, we identified a novel Vibrio parahaemolyticus effector protein that is similar to the VopG effector of Vibrio cholerae. VopG-like effectors were found in diverse species and contain a conserved serine/threonine kinase domain that bears similarity to the kinase domain in the enterohemorrhagic Escherichia coli (EHEC) and NleH effectors that manipulate host cell survival pathways and host immune responses. Together our findings identify a new family of effector proteins and highlight the role of horizontal gene transfer events among marine bacteria in shaping T3SS gene clusters.
Topics: Bacterial Proteins; Caco-2 Cells; Computational Biology; Gene Expression Regulation, Bacterial; Humans; Interleukin-8; Multigene Family; Protein Serine-Threonine Kinases; Protein Transport; Serine; Type III Secretion Systems; Vibrio parahaemolyticus
PubMed: 34346702
DOI: 10.1128/mSphere.00599-21 -
Applied and Environmental Microbiology Sep 1983We have examined the effect of complete cell recycle on the production of cholera toxin (CT) by Vibrio cholerae and CT-like toxin by Vibrio mimicus in continuous culture... (Comparative Study)
Comparative Study
We have examined the effect of complete cell recycle on the production of cholera toxin (CT) by Vibrio cholerae and CT-like toxin by Vibrio mimicus in continuous culture fermentations. Complete cell recycle was obtained by filtering culture fluids through Amicon hollow fibers with an exclusion limit of 100,000 daltons (H1P100-20) and returning the concentrated cell slurry to the fermentor. A single 1-liter laboratory fermentor system modified with this recycle loop was capable of producing over 20 liters of cell-free culture filtrate per day. Toxin production in this system was compared with yields obtained in traditional continuous cultures and in shake flask cultures. Yields of CT from V. cholerae 569B in the recycle fermentor were highest at the highest dilution rate employed (1.0 vol/vol per h). The use of complete cell recycle dramatically increased yields over those obtained in continuous culture and equaled those obtained in shake flasks. The concentration of CT in the filtrate was slightly less than half of that measured in culture fluids sampled at the same time. Similarly, V. mimicus 61892 grown in the presence of 50 micrograms of lincomycin per ml produced 280 ng of CT per ml in the recycle fermentor, compared with 210 ng/ml in shake flasks under optimal conditions. The sterile filtrate from this fermentation contained 110 ng/ml.
Topics: Cholera Toxin; Enterotoxins; Fermentation; Microbiological Techniques; Vibrio; Vibrio cholerae
PubMed: 6357081
DOI: 10.1128/aem.46.3.704-709.1983 -
Infection and Immunity Dec 1990A protease produced by Vibrio mimicus was purified to apparent homogeneity by ammonium sulfate fractionation and successive column chromatography on Sephacryl S-100 and...
A protease produced by Vibrio mimicus was purified to apparent homogeneity by ammonium sulfate fractionation and successive column chromatography on Sephacryl S-100 and Mono Q Monobeads. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) of the final preparation of the enzyme revealed the homogeneity of the purified enzyme. Conventional PAGE showed that the purified protease migrated as a single band with protease activity. The molecular weight of the protease was estimated to be about 31,000 on the basis of its mobility on sodium dodecyl sulfate-PAGE. The purified protease had both proteolytic and hemagglutination (HA) activities. The proteolytic and HA activities were inhibited by metalloprotease inhibitors and heat treatment. V. mimicus protease therefore appeared as a heat-labile, bifunctional molecule capable of mediating proteolysis and HA. The immunodiffusion analysis showed that the proteases produced by Vibrio cholerae and V. mimicus are immunologically cross-reactive.
Topics: Amino Acids; Endopeptidases; Hemagglutinins; Protease Inhibitors; Vibrio
PubMed: 2254038
DOI: 10.1128/iai.58.12.4159-4162.1990 -
Microbiology and Immunology 2004Distribution of virulence-associated genes in Vibrio mimicus was studied including the toxin genes ctxA, tdh, st and vmh and the genes necessary for regulation of toxin...
Distribution of virulence-associated genes in Vibrio mimicus was studied including the toxin genes ctxA, tdh, st and vmh and the genes necessary for regulation of toxin production, toxR, toxS, toxT, tcpA and tcpP. Approximately half of clinical V. mimicus isolates possessed one or more genes encoding V. cholerae enterotoxic factors such as ctxA, tdh and st. All of the clinical and environmental isolates possessed vmh encoding V. mimicus hemolysin (VMH). The ctxA encoding cholera toxin was detected in only 2 strains, 5% of the clinical isolates. Furthermore, there were very few strains possessing tcpP and toxT needed for the expression of ctxA. These results may suggest that VMH is a more important pathogenic factor than well recognized toxins such as cholera toxin (CT) in V. mimicus infection.
Topics: Bacterial Proteins; Bacterial Toxins; Cholera Toxin; Environmental Microbiology; Hemolysin Proteins; Humans; Vibrio; Vibrio Infections; Virulence
PubMed: 15272201
DOI: 10.1111/j.1348-0421.2004.tb03551.x -
Research in Microbiology Feb 1994The V1 and V2 variable regions of the 16S rRNA gene of three strains of V. cholerae and one strain of V. mimicus were amplified by PCR. Fragments containing both regions...
The V1 and V2 variable regions of the 16S rRNA gene of three strains of V. cholerae and one strain of V. mimicus were amplified by PCR. Fragments containing both regions were cloned into M13mp18 using Smal and sequenced by the dideoxy method. The 263-bp sequence from a strain isolated during the 1991 cholera outbreak in Brazil was deposited in Genbank under the accession number L05178. Except for an extra G in one of the strains, the three V. cholerae sequences were identical. The V. mimicus sequence was very similar, with only two substitutions. We compared these sequences with the Vibrio 16S rRNA sequences described by Dorsch et al. in 1992. It was noted that the V1 region, including helix 6 and its associated loop, comprised two different sizes and sequences in the various Vibrio species. While V. cholerae, V. mimicus, V. vulnificus, V. anguillarum and V. diazotrophicus had a 46-nucleotide V1, other species such as V. parahaemolyticus, V. proteolyticus, V. alginolyticus, V. campbellii and V. hollisae had longer 54- or 55-nucleotide regions, with a different consensus sequence. The phylogeny of Vibrio was analysed using the sequenced region and its equivalent in other species, by means of the "Phylip" software package. Species with a short helix 6 were grouped together, as were species with a long helix. Dorsh et al.'s analysis is discussed in relation to this "helix 6 split".
Topics: Cloning, Molecular; Genes, Bacterial; In Vitro Techniques; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, RNA; Vibrio; Vibrio cholerae
PubMed: 8090995
DOI: 10.1016/0923-2508(94)90008-6 -
Asian Pacific Journal of Tropical... Jan 2016To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum (M. amazonicum) farming and evaluate the in vitro antimicrobial susceptibility...
OBJECTIVE
To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum (M. amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains.
METHODS
Strains were isolated from female M. amazonicum prawns and environmental and hatchery water. Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification, through Vitek 2 automated system and serotyping. Susceptibility test was performed according to Clinical Laboratory Standards Institute.
RESULTS
The following genera of enterobacteria were recovered: Enterobacter (n = 11), Citrobacter (n = 10), Proteus (n = 2), Serratia (n = 2), Kluyvera (n = 2), Providencia (n = 2), Cedecea (n = 1), Escherichia (n = 1), Edwardsiella (n = 1) and Buttiauxella (n = 1). As for Vibrio, three species were identified: Vibrio cholerae non-O1/non-O139 (n = 4), Vibrio vulnificus (V. vulnificus) (n = 1) and Vibrio mimicus (n = 1). Vibrio spp. showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics, except for V. vulnificus, which presented intermediate profile to ampicillin.
CONCLUSIONS
Enterobacteria do not seem to be the most important pathogens associated with M. amazonicum farming, whereas the recovery of Vibrio spp. from larviculture, with emphasis on Vibrio cholerae and V. vulnificus, deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens. Furthermore, the intermediate susceptibility of V. vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.
PubMed: 26851782
DOI: 10.1016/j.apjtm.2015.12.006