Pdf production of vibrio cholerae accessory cholera. Filamentous phage associated with recent pandemic strains. The major virulence factors of toxigenic vibrio cholerae are cholera toxin ct, which is encoded by a lysogenic bacteriophage ctx. One of the few identified pathogens of coral disease is the bacterium vibrio coralliilyticus. In order to test whether k9 phage is involved in lysogenic conversion of v. The propagation of this filamentous phage can result in the origination of new toxigenic strains. Lysogenic conversion of environmental vibrio mimicus strains by ctxphi. Filamentous phage associated with recent pandemic strains of. Frontiers design and construction of vibrio cholerae. Dec 08, 2015 disease is an increasing threat to reefbuilding corals. Bacteriophage and the evolution of epidemic cholera. The flexibility of their capsid structure accommodates packaging of heterologous dna, phage production occurs without host cell lysis and in the presence of bacterial multiplication, and the pili they use as receptors are ubiquitous colonization factors for gramnegative bacteria. Induction of the lysogenic phage encoding cholera toxin in naturally occurring strains of. The seventh pandemic began in 1961 and affects 35 million people each year, killing 120 000.
Lysogenic conversion of environmental vibrio mimicus. Zonula occludens toxin zot is a conserved protein in filamentous vibriophages and has been reported as a putative toxin in vibrio cholerae. Secondly, type iv pili are required for lysogenic conversion of vibrio cholerae by a filamentous phage encoding cholera toxin waldor and mekalanos, 1996. Pdf filamentous vibriophage fs2 encoding the rst c gene. Phagebacterial interactions in the evolution of toxigenic vibrio. Trucksis m, galen je, michalski j, fasano a, kaper jb. Nov 26, 2003 the phage recognizes a pilus on the surface of the bacterium and uses it to enter the cell. Here we report characterization of a tlcrelated element that corresponds to the genome of a satellite filamentous phage tlckn. In some interactions between lysogenic phages and bacteria, the lysogenic conversion may occur, which can also be called phage conversion. A filamentous phage associated with recent pandemic vibrio parahaemolyticus o3. Lysogenic conversion of environmental vibrio mimicus strains.
Once inside the cell, the ctx phage integrates into the chromosome and the lysogen expresses cholera toxin. Molecular keys of the tropism of integration of the cholera. Virulence factors carried on phage san diego state university. Cholera toxin, the most important virulence factor of vibrio cholerae, has long been believed to be encoded in the chromosome of the bacterium, but recently it was revealed to be encoded within the genome of a lysogenic filamentous bacteriophage, ctx. Sunlightinduced propagation of the lysogenic phage encoding. Vgjphi integration and excision mechanisms contribute to. Accessory cholera enterotoxin ace is a recently identified toxin of vibrio cholerae. The genes coding for cholera toxin are borne on, and. The lack of purified toxin has hindered elucidation of the mechanism of action of ace. Although filamentous phage had not previously been recognized as being responsible for the lysogenic conversion of bacterial pathogens, they seem quite well suited for this purpose. Activation of the vibrio cholerae sos response is not.
Lysogenic filamentous vibriophages exploit xer recombinases. Changes can often involve the external membrane of the. Lysogenic conversion by a filamentous phage encoding cholera toxin lysogenic conversion by a filamentous phage encoding cholera toxin pp. All reported filamentous vibriophages are equipped with an autonomously replicating genetic module, with or without toxin encoding genes figure 2. Pathogenic potential of environmental vibrio cholerae strains.
Induction of the lysogenic phage encoding cholera toxin in. Lysogenic conversion by a filamentous bacteriophage encoding cholera toxin. Faruque s m, asadulghani, alim a r m a, albert m j, islam k m n, mekalanos j j. Mar 02, 2010 bacteriophage can convert their bacterial host from a nonpathogenic form to a pathogenic form by providing the bacterium with virulence genes, in a process called lysogenic phage conversion. Lysogenic conversion article about lysogenic conversion by.
The rstc protein was shown to increase production of cholera toxin ct and phage ctxf by forming aggregations with rstr davis et al. Frontiers mechanistic insights into filamentous phage. Cholera is an acute, secretory diarrhoea caused by infection with vibrio cholerae of the o1 or o9 serogroup. Rational approaches to the case management of cholera with oral and intravenous rehydration therapy have reduced the case fatality of cholera from more.
Molecular keys of the tropism of integration of the. Mechanistic insights into filamentous phage integration in. In toxigenic vibrio cholerae, the ctx genetic element which carries the genes for cholera toxin ct is the genome of a lysogenic bacteriophage ctx. Active surveillance for vibrio cholerae o1 and vibriophages. To understand the nature of possible environmental factors associated with the propagation of ctx. Encoding meaning in the cambridge english dictionary. The ct genes of o1 and o9 strains are carried by a filamentous bacteriophage termed ctx phage which is known to use toxin coregulated pili tcp as its receptor. Lysogenic conversion by a filamentous phage encoding. The examination of 7 nono1o9 vibrio cholerae isolates from newport bay, california, indicated the presence of diverse genotypes and a temporal succession. Edison in 1880 and published by aaas, today ranks as the worlds largest circulation general science journal. Although the genes encoding cholera toxin, ctxab, are known to have their own promoter, the toxin genes can also be transcribed from an upstream ctx.
Learn more in the cambridge englishchinese traditional dictionary. The filamentous bacteriophage ctxphi, which encodes cholera toxin ct in toxigenic vibrio cholerae, is known to propagate by infecting susceptible strains of v. It is endemic in more than 50 countries and also causes large epidemics. Cholera toxin is encoded in the genome of a lysogenic filamentous bacteriophage, ctx. Mar 02, 2010 cholera toxin is encoded in the genome of ctx. Vibrio cholerae is a bacterium prevalent in marine environments that can infect humans to cause the devastating diarrheal disease cholera, which is endemic in much of asia and africa. Pdf lysogenic conversion by a filamentous phage encoding. Prevalence of cholera toxin genes ctxa and zot among non. Clinical and environmental isolates of vibrio cholerae. This suggests that ctxa is prevalent in the region of nonepidemicity and is likely to have an. Cholera toxin, one of the main virulence factors of vibrio cholerae, is encoded in the genome of ctx. Lysogenic conversion by a filamentous phage encoding cholera toxin.
Pdf vibrio cholerae, the causative agent of cholera, requires two coordinately regulated factors for full virulence. Phage is similar in size, structure, and gene order in filamentous coliphages such as e. The structural genes for ct are shown here to be encoded by a filamentous bacteriophage designated ctx. The important lesson from this discovery is that many different types of phage may carry virulence factors, and transfer of virulence genes by phage may be a major. The following article is from the great soviet encyclopedia 1979. Nov 28, 2014 lysogenic filamentous vibriophages exploit xer recombinases.
Induction of the lysogenic phage encoding cholera toxin in naturally occurring strains of toxigenic vibrio cholerae o1 and o9. Cholera meaning in the cambridge english dictionary. Phage regulatory circuits and virulence gene expression. Lysogenic conversion by a filamentous phage encoding cholera. We report sporadic cases of a severe gastroenteritis associated with vibrio cholerae serogroup o141. Cholera is an acute, watery diarrhoeal disease caused by vibrio cholerae of the o1 or o9 serogroups. Pdf sunlightinduced propagation of the lysogenic phage. Most of the characterized filamentous vibriophages are lysogenic and integrate at the dif1 andor dif2 sites of v. For example, a number of strains of the diphtheria bacillus acquire the capacity to form. Accessory cholera enterotoxin ace, the third toxin of a vibrio cholerae virulence cassette. Survival and proliferation of the lysogenic bacteriophage ctx.
Diverse ctx phages among toxigenic vibrio cholerae o1 and. Frontiers cholera toxin production in vibrio cholerae o1. Filamentous bacteriophages of vibrios are integrated into the. All reported filamentous vibriophages are equipped with an autonomously replicating genetic module, with or without toxin encoding genes figure figure2. In toxigenic vibrio cholerae, the cholera enterotoxin ct is encoded by ctxphi, a lysogenic bacteriophage. The propagation of this filamentous phage can result in the origination of new toxigenic. The bacteriumproduced cholera toxin ct is mainly responsible for the clinical manifestations of cholera. Vibrio cholerae nono1 in sewage lagoons and seasonality in peru cholera epidemic.
Virulent strains of the bacterial pathogen vibrio cholerae cause the diarrheal disease cholera by releasing cholera toxin into the small intestine. The vibrio cholerae minor pilin tcpb mediates uptake of the. How these highly conserved surface organelles contribute to such diverse forms of dna translocation across membranes remains to be seen. Since 1817, seven cholera pandemics have spread from asia to much of the world. Rs1 element of vibrio cholerae can propagate horizontally as. The ct genes of o1 and o9 strains are carried by a filamentous bacteriophage termed ctx phage which is known to use. Pdf characterization of a vibrio cholerae phage isolated. Vibrio cholerae, the causative agent of cholera, requires two coordinately regulated factors for full virulence. It is when a temperate phage induces a change in the phenotype of the infected bacteria that is not part of a usual phage cycle. Bacteriophages can convert their bacterial host from a nonpathogenic strain through a process called phage conversion, providing phage encoded virulence genes to the host. Toxigenic vibrio cholerae strains are lysogens of a filamentous bacteriophage designated ctx. Virulence factors carried on phage san diego state. Examples of how to use filamentous in a sentence from the cambridge dictionary labs.
Mechanistic insights into filamentous phage integration. Diverse ctx phages among toxigenic vibrio cholerae o1 and o9 strains isolated between 1994 and 2002 in an area where cholera is endemic in bangladesh suraia nusrin, 1 g. Competence for natural transformation in neisseria. Ctx prophages in classical biotype vibrio cholerae. Lysogenic conversion article about lysogenic conversion. The genome of rs1 contains genes encoding proteins rstr, rsta, rstb and rstc.
470 243 827 798 340 292 595 877 793 732 254 974 1371 788 1604 707 140 686 642 450 1469 1477 1515 361