Pandemic strains of O3:K6Vibrio parahaemolyticusin the aquatic environment of Bangladesh

A total of 1500 environmental strains of Vibrio parahaemolyticus, isolated from the aquatic environment of Bangladesh, were screened for the presence of a major V. parahaemolyticus virulence factor, the thermostable direct haemolysin (tdh) gene, by the colony blot hybridization method using a digoxigenin-labeled tdh gene probe. Of 1500 strains, 5 carried the tdh sequence, which was further confirmed by PCR using primers specific for the tdh gene. Examination by PCR confirmed that the 5 strains were V. parahamolyticus and lacked the thermostable direct haemolysin-related haemolysin (trh) gene, the alternative major virulence gene known to be absent in pandemic strains. All 5 strains gave positive Kanagawa phenomenon reaction with characteristic β-haemolysis on Wagatsuma agar medium. Southern blot analysis of the HindIII-digested chromosomal DNA demonstrated, in all 5 strains, the presence of 2 tdh genes common to strains positive for Kanagawa phenomenon. However, the 5 strains were found to belong to 3 different serotypes (O3:K29, O4:K37, and O3:K6). The 2 with pandemic serotype O3:K6 gave positive results in group-specific PCR and ORF8 PCR assays, characteristics unique to the pandemic clone. Clonal variations among the 5 isolates were analyzed by comparing RAPD and ribotyping patterns. Results showed different patterns for the 3 serotypes, but the pattern was identical among the O3:K6 strains. This is the first report on the isolation of pandemic O3:K6 strains of V. parahaemolyticus from the aquatic environment of Bangladesh.Key words: pandemic strains, Vibrio parahaemolyticus, aquatic environment.

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Genotypic detection of some virulence factors among Aeromonas hydrophila Isolated from Diarrhea Cases (Iraq)

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v9ispl1.1353 ◽

2018 ◽

Vol 9 (SPL1) ◽

Cited By ~ 1

Author(s):

Ilham A Bunyan ◽

Israa K Obais

Keyword(s):

Virulence Factors ◽

Aeromonas Hydrophila ◽

Molecular Detection ◽

Virulence Gene ◽

Molecular Study ◽

Protease Gene ◽

Allelic Ladder ◽

Specific Pcr ◽

Molecular Length ◽

Positive Results

The present study included the detection ofsome virulence factorsof Aeromonas hydrophila under molecular level to clinical isolates were taken from patients suffering from diarrhea during the period from July (2017) to October (2017). Molecular detection of Hemolysin gene (ahh) was done for all isolates. The results showed that all isolates (100%) gave positive results for this virulence gene. the positive results were detected by the presence of (130) bp bands when compared with allelic ladder. The genomic DNA of the samples was extracted and bands were observed by performing agarose gel electrophoresis. When PCR was performed,results clearly indicate that all isolated organisms contained serine protease gene and all the amplified products produced a band at the level of (900 bp) when compared with the allelic ladder. Molecular detection of this gene was carried out by using a specific PCR primer were done by comparison with allelic ladder which gave a (309bp) It was found that (Aerolysin) gene present in (12) (75%) of the positive samples. Lip gene was also detected in A. hydrophila samples and found that all 16 samples (100%) gave positive results to this gene which gave molecular length (382) bp. Molecular study was carried out to show the sequence identity of cytotonic enterotoxins gene in Aeromonas spp. to that in A. hydrophila. Analysis of the A. hydrophila genome revealed a number of a putative virulence factors,including a gene that heat-labile cytotonic enterotoxin (alt). Our study showed that all (16) isolates (100%) gave positive results to this gene,which gave molecular length (442)bp. Molecular detection of cytotonic enterotoxins gene (ast) was done for (16) A. hydrophila isolates and the results showed that all isolates have this gene (100%). The positive results for (ast) virulence were detected by the presence of (331) bp band compared with allelic ladder.

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Serogroup, Virulence, and Genetic Traits of Vibrio parahaemolyticus in the Estuarine Ecosystem of Bangladesh

Applied and Environmental Microbiology ◽

10.1128/aem.00266-09 ◽

2009 ◽

Vol 75 (19) ◽

pp. 6268-6274 ◽

Cited By ~ 20

Author(s):

Munirul Alam ◽

Wasimul B. Chowdhury ◽

N. A. Bhuiyan ◽

Atiqul Islam ◽

Nur A. Hasan ◽

...

Keyword(s):

Vibrio Parahaemolyticus ◽

Marker Gene ◽

Human Health Risk ◽

Geographic Origin ◽

Virulence Gene ◽

Estuarine Ecosystem ◽

Genetic Traits ◽

Clinical Strains ◽

Pandemic Strains ◽

And Cluster Analysis

ABSTRACT Forty-two strains of Vibrio parahaemolyticus were isolated from Bay of Bengal estuaries and, with two clinical strains, analyzed for virulence, phenotypic, and molecular traits. Serological analysis indicated O8, O3, O1, and K21 to be the major O and K serogroups, respectively, and O8:K21, O1:KUT, and O3:KUT to be predominant. The K antigen(s) was untypeable, and pandemic serogroup O3:K6 was not detected. The presence of genes tox R and tlh were confirmed by PCR in all but two strains, which also lacked tox R. A total of 18 (41%) strains possessed the virulence gene encoding thermostable direct hemolysin (TDH), and one had the TDH-related hemolysin (trh) gene, but not tdh. Ten (23%) strains exhibited Kanagawa phenomenon that surrogates virulence, of which six, including the two clinical strains, possessed tdh. Of the 18 tdh-positive strains, 17 (94%), including the two clinical strains, had the seromarker O8:K21, one was O9:KUT, and the single trh-positive strain was O1:KUT. None had the group-specific or ORF8 pandemic marker gene. DNA fingerprinting employing pulsed-field gel electrophoresis (PFGE) of SfiI-digested DNA and cluster analysis showed divergence among the strains. Dendrograms constructed using PFGE (SfiI) images from a soft database, including those of pandemic and nonpandemic strains of diverse geographic origin, however, showed that local strains formed a cluster, i.e., “clonal cluster,” as did pandemic strains of diverse origin. The demonstrated prevalence of tdh-positive and diarrheagenic serogroup O8:K21 strains in coastal villages of Bangladesh indicates a significant human health risk for inhabitants.

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Filamentous Bacteriophages of Vibrio parahaemolyticus as a Possible Clue to Genetic Transmission

Journal of Bacteriology ◽

10.1128/jb.180.19.5094-5101.1998 ◽

1998 ◽

Vol 180 (19) ◽

pp. 5094-5101 ◽

Cited By ~ 30

Author(s):

Bin Chang ◽

Hatsumi Taniguchi ◽

Hiroshi Miyamoto ◽

Shin-ichi Yoshida

Keyword(s):

Vibrio Parahaemolyticus ◽

Genetic Interaction ◽

Blot Hybridization ◽

Gene Organization ◽

Chromosomal Dna ◽

Genetic Transmission ◽

Conserved Regions ◽

Isolation And Characterization ◽

Filamentous Bacteriophages ◽

Gene Structures

ABSTRACT We have previously reported the isolation and characterization of two filamentous bacteriophages of Vibrio parahaemolyticus, designated Vf12 and Vf33. In this study, to understand the potential of these phages as tools for genetic transmission, we investigated the gene structures of replicative-form (RF) DNAs of their genomes and the distribution of these DNAs on chromosomal and extrachromosomal DNAs. The 7,965-bp nucleotide sequences of Vf12 and Vf33 were determined. An analysis of the overall gene structures revealed that Vf12 and Vf33 had conserved regions and distinctive regions. The gene organization of their conserved regions was similar to that of CTX phage ofVibrio cholerae and coliphage Ff of Escherichia coli, while their distinctive regions were characteristic of Vf12 and Vf33 phage genomes. Southern blot hybridization testing revealed that the filamentous phage genomes integrated into chromosomal DNA ofV. parahaemolyticus at the distinctive region of the phage genome and were also distributed on some plasmids ofV. parahaemolyticus and total cellular DNAs of oneVibrio damsela and one nonagglutinable Vibriostrain tested. These results strongly suggest the possibilities of genetic interaction among the bacteriophage Vf12 and Vf33 genomes and chromosomal and plasmid-borne DNAs of V. parahaemolyticus strains and of genetic transmission among strains through these filamentous phages.

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Molecular Characterization of Vibrio parahaemolyticus Strains Associated with Foodborne Illness in Florida

Journal of Food Protection ◽

10.4315/0362-028x-70.10.2396 ◽

2007 ◽

Vol 70 (10) ◽

pp. 2396-2401 ◽

Cited By ~ 9

Author(s):

CARISA R. DAVIS ◽

DAVID L. WINGFIELD ◽

K. KEALY PEAK ◽

WILLIAM VEGUILLA ◽

PHILIP T. AMUSO ◽

...

Keyword(s):

Multilocus Sequence Typing ◽

Vibrio Parahaemolyticus ◽

The United States ◽

Pcr Markers ◽

Specific Pcr ◽

Foodborne Outbreaks ◽

Pcr Ribotyping ◽

Typing Methods ◽

Pandemic Strains ◽

Novel Alleles

Vibrio parahaemolyticus is the leading cause of bacterial seafood-based illness in the United States. Real-time PCR, pandemic group–specific PCR, ribotyping, and multilocus sequence typing were used to characterize 30 strains of V. parahaemolyticus including 11 strains associated with foodborne outbreaks in Florida and 6 known pandemic strains. Thirteen strains were positive for four pandemic group–specific PCR markers, including 5 strains associated with outbreaks in Florida. Molecular typing methods were used to further define the pandemic status of these strains because the current PCR markers are not sufficient to identify pandemic isolates. Nine of the Florida strains clustered with a majority of the known pandemic strains, based on ribotyping patterns using PvuII, but no isolated pandemic branch was formed. Using multilocus sequence typing, it was determined that 14 strains possess a previously determined pandemic sequence type. This study identified 13 novel sequence types and seven to nine novel alleles for each locus. Furthermore, the results indicate that seven of the strains from recent foodborne outbreaks in Florida are pandemic strains, and that multilocus sequence typing was the most accurate molecular method to identify these strains.

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Distribution of Virulent and Pandemic Strains of Vibrio parahaemolyticus in Three Molluscan Shellfish Species (Meretrix meretrix, Perna viridis, and Anadara granosa) and Their Association with Foodborne Disease in Southern Thailand

Journal of Food Protection ◽

10.4315/0362-028x-69.11.2615 ◽

2006 ◽

Vol 69 (11) ◽

pp. 2615-2620 ◽

Cited By ~ 21

Author(s):

VARAPORN VUDDHAKUL ◽

SUPATINEE SOBOON ◽

WATTANEE SUNGHIRAN ◽

SUKHON KAEWPIBOON ◽

ASHRAFUZZAMAN CHOWDHURY ◽

...

Keyword(s):

Vibrio Parahaemolyticus ◽

Immunomagnetic Separation ◽

Hard Clam ◽

Perna Viridis ◽

Clinical Strains ◽

Specific Pcr ◽

Alkaline Peptone Water ◽

Southern Thailand ◽

Peptone Water ◽

Pandemic Strains

Distribution of pandemic strains of Vibrio parahaemolyticus in seafood, particularly in molluscan shellfish, and their serological and molecular relationships to clinical strains were examined from Hat Yai City in southern Thailand. During 2000 to 2002, virulent strains (tdh+ or trh+) were isolated from 13 of 230 molluscan shellfish samples using alkaline peptone water enrichment followed by immunomagnetic separation. The isolates included 12 pandemic strains (tdh+, trh−, group-specific PCR positive) from five Oriental hard clam samples, five green mussel samples, and one bloody clam sample. Among the pandemic strains, eight belonged to serogroup O3:K6, three belonged to O1:K25, and one was O1:K untypeable. One hundred eighty-seven strains of V. parahaemolyticus were isolated from clinical specimens obtained from a hospital in this city during 2000 to 2001. The pandemic strains comprised 64 and 68% of the isolates in 2000 and 2001, respectively. Among the serotypes of the pandemic strains, O3:K6 was dominant at 73% in 2000 and 76% in 2001 followed by O1:K25 at 20% in 2000 and 13% in 2001. Pulsed-field gel electrophoresis profiles of the pandemic strains from molluscan shellfish were indistinguishable or very similar to those of patient isolates. Similarity of the serotype distribution and DNA fingerprints occurring between the molluscan shellfish strains and clinical strains suggests that molluscan shellfish may be an important source of pandemic V. parahaemolyticus infection in southern Thailand. For public health, proper cooking of molluscan shellfish in this area is strongly recommended.

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A decrease in the proportion of infections by pandemic Vibrio parahaemolyticus in Hat Yai Hospital, southern Thailand

Journal of Medical Microbiology ◽

10.1099/jmm.0.47439-0 ◽

2007 ◽

Vol 56 (12) ◽

pp. 1630-1638 ◽

Cited By ~ 20

Author(s):

Nutthakul Wootipoom ◽

Phuangthip Bhoopong ◽

Rattanaruji Pomwised ◽

Mitsuaki Nishibuchi ◽

Masanori Ishibashi ◽

...

Keyword(s):

Climate Change ◽

Vibrio Parahaemolyticus ◽

Public Hospital ◽

Virulence Genes ◽

Specific Pcr ◽

Southern Thailand ◽

Pcr Method ◽

Pandemic Strains ◽

Arbitrarily Primed Pcr ◽

Proportional Decrease

Infection by the pandemic clone of Vibrio parahaemolyticus is prevalent in southern Thailand. This study actively surveyed the incidence of V. parahaemolyticus infection in this area. A total of 865 isolates of V. parahaemolyticus was obtained from patients at Hat Yai Hospital, the main public hospital in Songkhla Province, Thailand, from 2000 to 2005. The isolates were examined by group-specific PCR (GS-PCR) specific for the pandemic clone, and for the presence of two major virulence genes, tdh and trh, and the O : K serotype. Representative isolates were also examined by antibiogram pattern and DNA fingerprinting using an arbitrarily primed PCR method to determine the clonal relationships between isolates. The total number of isolates was less in 2000 and more in 2004 and 2005 than in the years 2001–2003. The increase in the numbers of infections in 2004 and 2005 was not due to the emergence of a particular clone having unique characteristics, but was probably due to climate change. From 2000 to 2003, the percentages of pandemic strains of V. parahaemolyticus, defined as GS-PCR-positive tdh + trh −, was stable at 64.1, 67.5, 69.7 and 67.7 % of the total isolates each year, respectively. However, in 2004 and 2005, the percentages decreased to 56.1 and 55.5 %, respectively. The O : K serotypes of the pandemic isolates remained unchanged. The proportional decrease in infections caused by the pandemic strains are probably due to the population in this area gradually developing immunity to the pandemic clone whilst continuing to be susceptible to other strains.

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Detection of Hepatitis a Virus and other Enteroviruses in Wastewater and Surface Water Samples by Gene Probe Assay

Water Science & Technology ◽

10.2166/wst.1991.0071 ◽

1991 ◽

Vol 24 (2) ◽

pp. 267-272 ◽

Cited By ~ 12

Author(s):

S. Dubrou ◽

H. Kopecka ◽

J. M. Lopez Pila ◽

J. Maréchal ◽

J. Prévot

Keyword(s):

Surface Water ◽

Cell Cultures ◽

Hepatitis A ◽

Hepatitis A Virus ◽

Limit Of Detection ◽

Blot Hybridization ◽

Noncoding Region ◽

Gene Probe ◽

Dot Blot ◽

Lower Efficiency

Enteroviruses were specifically detected by dot blot hybridization when using poliovirus type 1 (PV1) derived subgenomic radiolabeled cRNA probes (riboprobes) in environmental water specimens and in the cell cultures in which the viruses were amplificated. The riboprobe corresponding to the 5' noncoding sequence detected the majority of enteroviruses. Hepatitis A virus (HAV) was specifically detected by an HAV cRNA probe corresponding to the 5' noncoding region of its genome. By this test, the limit of detection of coxsackievirus B5 and echovirus 7 seeded in mineral water was 103 to 104 PFU/spot. In cell cultures, positive signals were observed in the lysates of cells infected by one PFU. Higher positive signals were obtained with a short PV1 probe (nt 221-670) corresponding to the 5' noncoding region, which is a well preserved sequence among the enteroviruses, than with PV1 genomic probe. Hybridization allowed a good detection of enteroviral RNAs in wastewater specimens, but with a lower efficiency in surface water. In this case, amplification of viruses in the cell cultures gave significant hybridization results.

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Comparison of two rapid tests for the detection of legionellaceae in water: a microbiological-immunological method and a commercial gene-probe testkit

Water Science & Technology ◽

10.2166/wst.1995.0648 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 403-406 ◽

Cited By ~ 1

Author(s):

E. Frahm ◽

U. Obst

Keyword(s):

Monoclonal Antibodies ◽

Conventional Method ◽

Standard Method ◽

False Positive ◽

Gene Probe ◽

Immunological Method ◽

Probe Test ◽

Rapid Tests ◽

Positive Results

Two recently developed Legionella detection tests, a microbiological-immunological method based on monoclonal antibodies (carried out as a colony-blot assay) and a commercial gene-probe testkit (the EnvironAmp Legionella Kit), are compared with the standard method. The colony-blot assay is faster than the conventional method; the gene-probe test is much faster still and is the most sensitive, but in consequence is at greater risk of false-positive results.

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