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Mukherjee M, Kakarla P, Kumar S, Gonzalez E, Floyd JT, Inupakutika M, Devireddy AR, Tirrell SR, Bruns M, He G, Lindquist IE, Sundararajan A, Schilkey FD, Mudge J, Varela MF. Comparative genome analysis of non-toxigenic non-O1 versus toxigenic O1 Vibrio cholerae.. ACTA ACUST UNITED AC 2014; 2:1-15. [PMID: 25722857 PMCID: PMC4338557 DOI: 10.7243/2052-7993-2-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain, in order to identify novel genes potentially responsible for virulence. In this study, we compared the whole genome of the non-O1 PS15 strain to the whole genomes of toxigenic serotypes at the phylogenetic level, and found that the PS15 genome was distantly related to those of toxigenic V. cholerae. Thus we focused on a detailed gene comparison between PS15 and the distantly related O1 V. cholerae N16961. Based on sequence alignment we tentatively assigned chromosome numbers 1 and 2 to elements within the genome of non-O1 V. cholerae PS15. Further, we found that PS15 and O1 V. cholerae N16961 shared 98% identity and 766 genes, but of the genes present in N16961 that were missing in the non-O1 V. cholerae PS15 genome, 56 were predicted to encode not only for virulence-related genes (colonization, antimicrobial resistance, and regulation of persister cells) but also genes involved in the metabolic biosynthesis of lipids, nucleosides and sulfur compounds. Additionally, we found 113 genes unique to PS15 that were predicted to encode other properties related to virulence, disease, defense, membrane transport, and DNA metabolism. Here, we identified distinctive and novel genomic elements between O1 and non-O1 V. cholerae genomes as potential virulence factors and, thus, targets for future therapeutics. Modulation of such novel targets may eventually enhance eradication efforts of endemic and pandemic disease cholera in afflicted nations.
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Affiliation(s)
- Munmun Mukherjee
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Prathusha Kakarla
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Sanath Kumar
- QC Laboratory, Harvest and Post Harvest Technology Division, Central Institute of Fisheries Education (CIFE), Seven Bungalows, Versova, Andheri (W), Mumbai 400061, India
| | - Esmeralda Gonzalez
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Jared T Floyd
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Madhuri Inupakutika
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Amith Reddy Devireddy
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Selena R Tirrell
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Merissa Bruns
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
| | - Guixin He
- University of Massachusetts Lowell, Department of Clinical Laboratory and Nutritional Sciences, Lowell, MA 01854, USA
| | | | | | - Faye D Schilkey
- National Center for Genome Resources, Santa Fe, New Mexico, 87505, USA
| | - Joann Mudge
- National Center for Genome Resources, Santa Fe, New Mexico, 87505, USA
| | - Manuel F Varela
- Eastern New Mexico University, Department of Biology, Portales, New Mexico, 88130, USA
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Stine OC, Morris JG. Circulation and transmission of clones of Vibrio cholerae during cholera outbreaks. Curr Top Microbiol Immunol 2013; 379:181-93. [PMID: 24407776 DOI: 10.1007/82_2013_360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cholera is still a major public health problem. The underlying bacterial pathogen Vibrio cholerae (V. cholerae) is evolving and some of its mutations have set the stage for outbreaks. After V. cholerae acquired the mobile elements VSP I & II, the El Tor pandemic began and spread across the tropics. The replacement of the O1 serotype encoding genes with the O139 encoding genes triggered an outbreak that swept across the Indian subcontinent. The sxt element generated a third selective sweep and most recently a fourth sweep was associated with the exchange of the El Tor ctx allele for a classical ctx allele in the El Tor background. In Kenya, variants of this fourth selective sweep have differentiated and become endemic residing in and emerging from environmental reservoirs. On a local level, studies in Bangladesh have revealed that outbreaks may arise from a nonrandom subset of the genetic lineages in the environment and as the population of the pathogen expands, many novel mutations may be found increasing the amount of genetic variation, a phenomenon known as a founder flush. In Haiti, after the initial invasion and expansion of V. cholerae in 2010, a second outbreak occurred in the winter of 2011-2012 driven by natural selection of specific mutations.
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Affiliation(s)
- O Colin Stine
- Department of Epidemiology and Public Health, University of Maryland, 596 Howard Hall, 660 W. Redwood St., Baltimore, MD, 21201, USA,
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