Replication and integration of a <i>Vibrio cholerae</i> cryptic plasmid linked to the CTX prophage

Rubín, Eric J.; Lin, Wei; Mekalanos, John J.; Waldor, Matthew K.

doi:10.1046/j.1365-2958.1998.00889.x

Cited by 68 publications

(64 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar type of analysis done on the genomes of different classical strains revealed specific loci for the integration of CTX prophage in the large and small chromosomes (Davis et al, 2000). In the large chromosome of classical, El Tor and O139 strains, CTXf is located between the tlc and rtx gene clusters (Davis et al, 2000;Heidelberg et al, 2000;Lin et al, 1999;Rubin et al, 1998), while in the small chromosome of classical strains it is located between the traF and yciH genetic loci. In El Tor vibrios the same region of the small chromosome contains only a 14 bp end repeat sequence (Davis et al, 2000).…”

Section: Mapping Of the Locations Of Ctx Prophage In The El Tor Genomesmentioning

confidence: 80%

Genesis of variants of Vibrio cholerae O1 biotype El Tor: role of the CTX array and its position in the genome

et al. 2003

View full text Add to dashboard Cite

The gene encoding cholera toxin, the principal virulence factor of Vibrio cholerae, is encoded by a filamentous, lysogenic bacteriophage known as CTXf. The genome of V. cholerae, the host for CTXf, consists of two chromosomes, one large and one small. Here, it is shown that localization and array of CTX prophage DNA in either the large or small chromosome of V. cholerae is likely to be one of the reasons for the emergence of O1 biotype El Tor variants isolated just before and after the V. cholerae O139 cholera outbreak in 1992. Analyses of the organization of the CTX region of the genome of pre-O139 El Tor strains revealed that these strains carry two distinct CTX prophages integrated in the small chromosome in tandem: CTX ET , the prophage having a conserved NotI site in its repeat sequence segment which seems to be specific for the El Tor strains so far examined, followed by CTX calc -like genome, the prophage found in recent O139 clinical isolates from Calcutta. In sharp contrast, in post-O139 El Tor strains only one copy of the CTX ET prophage was found to be integrated in the large chromosome. To the authors' knowledge, the presence of CTX prophage in the small chromosome of O1 El Tor strains has not been reported previously. It is also shown that the difference in the CTX copy number and the position of the bacteriophage on the genomes of pre-and post-O139 El Tor strains have an effect on cholera toxin production. While a pre-O139 strain produced maximum cholera toxin in yeast extract/peptone medium at 30˚C, a post-O139 El Tor strain showed maximal yield at 37˚C, indicating differential regulation of cholera toxin between the strains. It appears from this study that the variation in the integration site of the CTX prophage, its copy number and the presence of diverse phage genomes in V. cholerae O1 biotype El Tor may be strategically important for generating variants with subtle phenotypic modulations of virulence factor production in this longest-ruling seventh pandemic strain.

show abstract

Section: Mapping Of the Locations Of Ctx Prophage In The El Tor Genomesmentioning

confidence: 80%

Genesis of variants of Vibrio cholerae O1 biotype El Tor: role of the CTX array and its position in the genome

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Chromosomal attachment sites for CTX are known to harbor other genetic elements, including toxin-linked cryptic (TLC), RS1 elements, and VSK(ϭpre-CTX) prophages (20,21). We have discovered five genomic islands (GI-19, GI-22, GI-33, GI-43, GI-48; for details see Table S1) in the region of the CTX attachment sites on both chromosomes.…”

Section: Resultsmentioning

confidence: 99%

Comparative genomics reveals mechanism for short-term and long-term clonal transitions in pandemic Vibrio cholerae

Chun

Grim

Hasan

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

351

422

View full text Add to dashboard Cite

Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the sixth and the current seventh pandemics, respectively. Cholera researchers continually face newly emerging and reemerging pathogenic clones carrying diverse combinations of phenotypic and genotypic properties, which significantly hampered control of the disease. To elucidate evolutionary mechanisms governing genetic diversity of pandemic V. cholerae, we compared the genome sequences of 23 V. cholerae strains isolated from a variety of sources over the past 98 years. The genome-based phylogeny revealed 12 distinct V. cholerae lineages, of which one comprises both O1 classical and El Tor biotypes. All seventh pandemic clones share nearly identical gene content. Using analogy to influenza virology, we define the transition from sixth to seventh pandemic strains as a ''shift'' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages. In contrast, transition among clones during the present pandemic period is characterized as a ''drift'' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V. cholerae O139 and V. cholerae O1 El Tor hybrid clones. Based on the comparative genomics it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to define pathogenic V. cholerae clones.genomic islands ͉ cholera toxin prophage ͉ lateral gene transfer

show abstract

“…The classical biotype properties of the Mozambique variant included detection of classical CTX prophage (CTX Cl ) localized in the small chromosome and absence of RS1 (Das et al, 2007;Faruque et al, 2007). In addition, these strains were also devoid of the toxin linked cryptic plasmid (pTLC) (Rubin et al, 1998). Comparative analysis of the PFGE profiles of Matlab and Mozambique variants revealed that these two groups of strains belonged to different clones (Ansaruzzaman et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Vibrio cholerae O1 clinical strains isolated in 1992 in Kolkata with progenitor traits of the 2004 Mozambique variant

Chatterjee

Patra

Ghosh

et al. 2009

Journal of Medical Microbiology

View full text Add to dashboard Cite

Retrospective analysis led to the detection of two Vibrio cholerae variant O1 strains (VC51 and VC53), which were isolated in 1992 in Kolkata from clinical cases, with identical traits to 2004 Mozambique variant O1 strains. The Mozambique O1 strains that caused a huge outbreak in 2004 have been shown to have phenotypic traits of both classical and El Tor biotypes, and thereby have been reported as variant. Our study demonstrated that two O1 strains isolated in Kolkata during 1992 were of the El Tor background as evidenced by polymyxin B (50 U ml "1 ) resistance, positivity in Voges-Proskauer reactions and sensitivity to biotype-specific vibrio phages. With the features of classical CTX prophage, localization in the small chromosome, and an absence of RS1 and pTLC, both Mozambique and Kolkata strains appeared to be identical. Furthermore, two Kolkata strains exhibited an identical ribotype to that of the Mozambique variant, displaying ribotype pattern RI that had been assigned to Kolkata V. cholerae O1 strains isolated on or before 1992. NotI pulsotype analysis indicated that these 1992 Kolkata strains along with the Mozambique variant O1 belonged to very closely related clones. Considering the chronological events, and the typical identity at the phenotypic and the genotypic level between the two O1 strains isolated during 1992 from Kolkata and during 2004 from Mozambique, we propose that some of the 1992 Kolkata O1 strains might have acted as progenitors for Mozambique variant O1 strains.

show abstract

Replication and integration of a Vibrio cholerae cryptic plasmid linked to the CTX prophage

Cited by 68 publications

References 30 publications

Genesis of variants of Vibrio cholerae O1 biotype El Tor: role of the CTX array and its position in the genome

Genesis of variants of Vibrio cholerae O1 biotype El Tor: role of the CTX array and its position in the genome

Comparative genomics reveals mechanism for short-term and long-term clonal transitions in pandemic Vibrio cholerae

Vibrio cholerae O1 clinical strains isolated in 1992 in Kolkata with progenitor traits of the 2004 Mozambique variant

Contact Info

Product

Resources

About