Journal ArticleDOI
Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains isolated before, during and after the O139 outbreak based on the intergenomic heterogeneity of the 16S-23S rRNA intergenic spacer regions
TLDR
Phylogenetic analysis conducted with all three ISR classes showed that the pre-O 139 serogroup and post-O139 serogroups O1 El Tor strains arose out of two independent clones, which was congruent with the observation made by earlier workers suggesting that analyses of ISR-C andISR-h, instead of all fiveISR classes, could be successfully used to study phylogeny in this organism.Abstract:
We have cloned, sequenced and analysed all the five classes of the intergenic (16S-23S rRNA) spacer region (ISR) associated with the eightrrn operons (rrna-rrnh) ofVibrio cholerae serogroup O1 El Tor strains isolated before, during and after the O139 outbreak. ISR classes ‘a’ and ‘g’ were found to be invariant, ISR-B (ISRb and ISRe) exhibited very little variation, whereas ISR-C (ISRc, ISRd, and ISRf) and ISRh showed the maximum variation. Phylogenetic analysis conducted with all three ISR classes (ISR-B, ISR-C and ISRh) showed that the pre-O139 serogroup and post-O139 serogroup O1 El Tor strains arose out of two independent clones, which was congruent with the observation made by earlier workers suggesting that analyses of ISR-C and ISR-h, instead of all five ISR classes, could be successfully used to study phylogeny in this organism.read more
Citations
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The use of molecular techniques to characterize the microbial communities in contaminated soil and water
TL;DR: This review examines the current application of molecular techniques for the characterization of microbial communities in contaminated soil and water and methods that directly link microbial phylogeny to its ecological function at contaminated sites as well as high throughput methods for complex microbial community studies.
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Characterization of potentially virulent non-O1/non-O139 Vibrio cholerae strains isolated from human patients
F.A.M.O. Cariri,Ana Paula Rocha da Costa,C.C. Melo,Grace Nazareth Diogo Theophilo,Ernesto Hofer,O.P. de Melo Neto,Nilma Cintra Leal +6 more
TL;DR: In this paper, the presence of the O1-specific wbeN gene was investigated through PCR and found to be restricted to strain 17155, as well as one of O26 strains, 4756, although neither strain was recognized by O1specific antisera.
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Emergence of novel strain of vibrio cholerae with epidermic potential in southern and eastern indian
T. Ramamurthy,Surabhi Garg,R. B. Sharma,S. K. Bhattacharya,G. Balakrish Nair,Toshio Shimada,Tae Takeda,Tadahiro Karasawa,Hisao Kurazano,Amit Pal +9 more
Advances in Molecular Biology Approaches to Guage Microbial Communities and Bioremediation at Contaminated Sites
TL;DR: The potential for the use of molecular methods in toxicological risk assessment and in developing bioremediation strategies is expanding rapidly as new methodologies become available.
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Application of Molecular Microbiology Techniques in Bioremediation of Hydrocarbons and Other Pollutants
TL;DR: The application of molecular microbiology techniques Studying microbial populations in polluted sites without the need for culturing has led to the discovery of novel and unrecog nized populations.
References
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Journal ArticleDOI
The role of recombination and mutation in 16s-23s rdna spacer rearrangements
TL;DR: A model is proposed that postulates a role for recombination and AT-expansion in intra-genomic ISR variations and may represent a general mechanism of concerted evolution for bacterial ISR rearrangements.
Journal ArticleDOI
Evolutionary Relationships of Pathogenic Clones of Vibrio cholerae by Sequence Analysis of Four Housekeeping Genes
TL;DR: The results show that the three pathogenic clones of V. cholerae are very closely related and that there has been a high level of recombination in their evolution.
Journal ArticleDOI
Molecular Characterization of Vibrio cholerae O1 Biotype El Tor Strains Isolated between 1992 and 1995 in Calcutta, India: Evidence for the Emergence of a New Clone of the El Tor Biotype
Charu Sharma,Gopinath Balakrish Nair,Mukhopadhyay Ak,S. K. Bhattacharya,R. K. Ghosh,A. N. Ghosh +5 more
TL;DR: These studies clearly showed that El Tor O1 strains, which displaced V. cholerae O139 in Calcutta, belonged to a new clone and suggested that there is a continuous genetic reassortment among El Tor strains of V.Cholera O1.
Journal ArticleDOI
Unique organization of the CTX genetic element in Vibrio cholerae O139 strains which reemerged in Calcutta, India, in September 1996.
Charu Sharma,Sankar Maiti,Asish K. Mukhopadhyay,A Basu,Indira Basu,Gopinath Balakrish Nair,R Mukhopadhyaya,Bhabatosh Das,Sudeshna Kar,R. K. Ghosh,Alip Ghosh +10 more
TL;DR: While the strains from this resurgence were indistinguishable from the earlier strains by ribotyping, the structure of the CTX genetic element present in the current O139 strains was found to be unconventional.
Journal ArticleDOI
Integration of the DNA of a novel filamentous bacteriophage VSK from Vibrio cholerae 0139 into the host chromosomal DNA
TL;DR: An unusual filamentous bacteriophage, VSK, containing single-stranded, circular DNA as its genome was isolated from Vibrio cholerae 0139 strains P07 and B04 and the attachment site (attP) on the viral genome was identified.