Identification of Vibrio cholerae by enzyme electrophoresis

Salles, C. A.; Momen, Hooman

doi:10.1016/0035-9203(91)90251-s

Cited by 39 publications

(25 citation statements)

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“…Studies of V. cholerae by restriction fragment length polymorphism of rRNA genes, pulsed-field gel electrophoresis, and multilocus enzyme electrophoresis (MLEE) have together shown convincingly that the sixth and seventh pandemics constitute two distinct clones (7,22,24,37,48). Ribotyping also allowed us to gain some insight into evolution within the seventh pandemic; however, the evolutionary relationship of this clone to other major clones of V. cholerae could not be accurately determined, since the variation between the clones was too high to be identified in terms of specific loci and alleles (22).…”

Section: Discussionmentioning

confidence: 99%

The sixth and seventh cholera pandemics are due to independent clones separately derived from environmental, nontoxigenic, non-O1 Vibrio cholerae

1995

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The DNA sequences of the asd genes from 45 isolates of Vibrio cholerae (19 clinical O1 isolates, 2 environmental nontoxigenic O1 isolates, and 24 isolates with different non-O1 antigens) were determined. No differences were found within either sixth-or seventh-pandemic isolates; however, variation was found between the two forms and among the non-O1 isolates. O139 isolates had sequences identical to those of seventh-pandemic isolates. Phylogenetic trees with Vibrio mimicus as the outgroup suggest that the sixth-pandemic, seventhpandemic, and U.S. Gulf isolates are three clones that have evolved independently from different lineages of environmental, nontoxigenic, non-O1 V. cholerae isolates. There is evidence for horizontal transfer of O antigen, since isolates with nearly identical asd sequences had different O antigens, and isolates with the O1 antigen did not cluster together but were found in different lineages. We also found evidence for recombination events within the asd gene of V. cholerae. V. cholerae may have a higher level of genetic exchange and a lower level of clonality than species such as Salmonella enterica and Escherichia coli.Vibrio cholerae is a normal inhabitant of aquatic environments (46). However, contaminated water supplies in some areas of the world have enabled some clones of the species to become pathogenic for humans. Seven pandemics of cholera have been recorded previously (12,36). The seventh pandemic, beginning in 1961, is clonal (20,22,24,37), is well defined, and has a known starting date, and previous studies (7,22,24,37,53) have shown it to have accumulated variation, with both random genetic drift and recombination possibly being involved. There are 140 known serotypes of V. cholerae (50). Until recently, all recorded pandemic and epidemic cases of cholera have been associated with the type O1 antigen; however, an epidemic which began in India late in 1992 and spread to several neighboring countries is caused by an O139 strain (1,8,33,39). Studies have shown that the O139 strain is genetically very similar to strains of the seventh pandemic (13,22,37,54). Karaolis et al. (22) have further shown that O139 isolates appear to have evolved from early seventh-pandemic isolates. Biochemically, it is nearly impossible to distinguish O1 and non-O1 V. cholerae (10,38). V. cholerae non-O1 strains are far more frequently isolated from environmental sources than O1 strains and appear to constitute part of the normal microflora of prawns (31) and oysters (2,4,28,47). Most environmental isolates do not possess cholera toxin genes, a heat-stable enterotoxin (31, 32), or toxin coregulated pilus (49, 54).The population structure and molecular evolution of V. cholerae as a species have not been well characterized, and the relationship of the sixth-and seventh-pandemic isolates is not clear. We have investigated sequence variation within V. cholerae by examining variation in the asd locus, one of the few V. cholerae chromosomal housekeeping genes sequenced to date. Housekeeping genes are conce...

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Section: Discussionmentioning

confidence: 99%

The sixth and seventh cholera pandemics are due to independent clones separately derived from environmental, nontoxigenic, non-O1 Vibrio cholerae

1995

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“…The enzyme loci mentioned in the tables and text have been described previously (Salles & Momen 1991). They are: ACO (aconitase hydratase); ADH (alanine dehydrogenase); IDH (isocitrate dehydrogenase); ME (malic enzyme); NSE (carboxilesterase); PGD (6-phosphogluconate dehydrogenase); MDH (malate dehydrogenase); PGM (phosphoglucomutase); GPI (glucose phosphate isomerase); G6P (glucose-6-phosphatedehydrogenase) ; PD (proline dipeptidase); P1 (peptidase leucyl-leucyl-leucine); P2 (peptidase leucyl glycil glycine) with the addition of the locus LAP: leucyl leucyl aminopeptidase (Pasteur et al 1990).…”

Section: Methodsmentioning

confidence: 99%

“…Most of the general bacteriological, electrophoretical and computational procedures have been described previously (Salles & Momen 1991).…”

Section: Methodsmentioning

confidence: 99%

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The Zymovars of Vibrio cholerae: Multilocus Enzyme Electrophoresis of Vibrio cholerae

Freitas

Momen

Salles

2002

Mem. Inst. Oswaldo Cruz

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“…The evolutionary genetic relationships among V. cholerae strains have been examined by multilocus enzyme electrophoresis (2,11,19,20,54,58), single locus sequence analysis (7,37,38,59), and multilocus sequence analysis of housekeeping genes (9,36,40). These analyses have given conflicting results regarding the ancestry of O1 serogroup classical and El Tor biotype strains.…”

mentioning

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Evolutionary Genetic Analysis of the Emergence of Epidemic Vibrio cholerae Isolates on the Basis of Comparative Nucleotide Sequence Analysis and Multilocus Virulence Gene Profiles

et al. 2004

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Vibrio cholerae, the causative agent of cholera, is a natural inhabitant of the aquatic ecosystem. We examined a unique collection of V. cholerae clinical and environmental isolates of widespread geographic distribution recovered over a 60-year period to determine their evolutionary genetic relationships based on analysis of two housekeeping genes, malate dehydrogenase (mdh) and a chaperonin (groEL). In addition, the phylogenetic distribution of 12 regions associated with virulence was determined. Comparative sequence analysis of mdh revealed that all V. cholerae O1 and O139 serogroup isolates belonged to the same clonal lineage. Single-strand conformational polymorphism (SSCP) analysis of these O1 and O139 strains at groEL confirmed the presence of an epidemic clonal complex. Of the 12 virulence regions examined, only three regions, Vibrio seventh pandemic island 1 (VSP-I), VSP-II, and RS1, were absent from all classical V. cholerae isolates. Most V. cholerae El Tor biotype and O139 serogroup isolates examined encoded all 12 virulence regions assayed. Outside of V. cholerae O1/O139 serogroup isolates, only one strain, VO7, contained VSP-I. Two V. cholerae El Tor isolates, GP155 and 2164-78, lacked both VSP-I and VSP-II, and one El Tor isolate, GP43, lacked VSP-II. Five non-O1/non-O139 serogroup isolates had an mdh sequence identical to that of the epidemic O1 and O139 strains. These isolates, similar to classical strains, lack both VSP-I and VSP-II. Four of the 12 virulence regions examined were found to be present in all isolates: hlyA, pilE, MSHA and RTX. Among non-O1/non-O139 isolates, however, the occurrence of the additional eight regions was considerably lower. The evolutionary relationships and multilocus virulence gene profiles of V. cholerae natural isolates indicate that consecutive pandemic strains arose from a common O1 serogroup progenitor through the successive acquisition of new virulence regions.

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Identification of Vibrio cholerae by enzyme electrophoresis

Cited by 39 publications

References 11 publications

The sixth and seventh cholera pandemics are due to independent clones separately derived from environmental, nontoxigenic, non-O1 Vibrio cholerae

The sixth and seventh cholera pandemics are due to independent clones separately derived from environmental, nontoxigenic, non-O1 Vibrio cholerae

The Zymovars of Vibrio cholerae: Multilocus Enzyme Electrophoresis of Vibrio cholerae

Evolutionary Genetic Analysis of the Emergence of Epidemic Vibrio cholerae Isolates on the Basis of Comparative Nucleotide Sequence Analysis and Multilocus Virulence Gene Profiles

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