scholarly journals THE INFLUENCE OF SOME FACTORS ON THE FORMATION OF BIOFILM BY TOXIGENIC AND NON-TOXIGENIC VIBRIO CHOLERAE EL TOR STRAINS

2012 ◽  
Vol 17 (5) ◽  
pp. 36-40
Author(s):  
O. A. Tatarenko ◽  
L. P. Alekseeva ◽  
N. R. Telesmanich ◽  
I. S. Shestialtynova ◽  
O. C. Chemisova ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Culture Medium ◽  
Microtiter Plate ◽  
Medium Composition ◽  
Medium Temperature ◽  
Exopolysaccharide Production ◽  
Medium Interface ◽  
Toxigenic Strains ◽  
El Tor

The early stages of biofilm formation on polystyrene surface were studied in 14 Vibrio cholerae El Tor strains, all of which carried genes of vps cluster, mshA, and hapR genes. 13 Vibrio cholerae El Tor strains were shown to be capable of adsorption on the walls of microtiter plate wells and of ring formation at the "polystyrene-medium" interface. One of the Vibrio cholerae El Tor strains tested was defective in this ability. The use of different media - modified M1 medium and 1 per cent peptone - failed to reveal sufficient influence of culture medium composition on the ability of Vibrio cholerae to form multilayer biofilm at the phase boundary "polystyrene-medium". Temperature reduction from 37°C to 25°C also didn t result in statistically significant enhancement of monolayer formation in both media. Quantitative evaluation of biofilm formation showed that this ability was clearly marked only in two toxigenic and two non-toxigenic strains of Vibrio cholerae El Tor. Monolayer comparison in ELISA demonstrated that only two toxigenic and two non-toxigenic strains possessed the ability for exopolysaccharide production.

scholarly journals High-Frequency Rugose Exopolysaccharide Production by Vibrio cholerae

2002 ◽  
Vol 68 (11) ◽  
pp. 5773-5778 ◽  
Author(s):  
Afsar Ali ◽  
Mohammed H. Rashid ◽  
David K. R. Karaolis
Keyword(s):  
Vibrio Cholerae ◽  
High Frequency ◽  
Biofilm Formation ◽  
Colony Morphology ◽  
Exopolysaccharide Production ◽  
Clinical Strains ◽  
Environmental Survival ◽  
El Tor

ABSTRACT Vibrio cholerae can shift to a “rugose” phenotype, thereby producing copious exopolysaccharide (EPS), which promotes its environmental survival and persistence. We report conditions that promote high-frequency rugose EPS production (HFRP), whereby cells switch at high frequency (up to 80%) to rugose EPS production. HFRP appeared to be more common in clinical strains, as HFRP was found in 6 of 19 clinical strains (32%) (including classical, El Tor, and non-O1 strains) but in only 1 of 16 environmental strains (6%). Differences were found between strains in rugose colony morphology, conditions promoting HFRP, the frequency of rugose-to-smooth (R-S) cell reversion, and biofilm formation. We propose that rugose EPS and HFRP provide an evolutionary and adaptive advantage to specific epidemic V. cholerae strains for increased persistence in the environment.

scholarly journals Distinct Sensory Pathways in Vibrio cholerae El Tor and Classical Biotypes Modulate Cyclic Dimeric GMP Levels To Control Biofilm Formation

2008 ◽  
Vol 191 (1) ◽  
pp. 169-177 ◽  
Author(s):  
Brian K. Hammer ◽  
Bonnie L. Bassler
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Target Genes ◽  
Cell Communication ◽  
Luciferase Expression ◽  
Signal Molecules ◽  
Exopolysaccharide Production ◽  
Sensory Pathways ◽  
Pandemic Strains ◽  
El Tor

ABSTRACT Quorum sensing (QS), or cell-cell communication in bacteria, is achieved through the production and subsequent response to the accumulation of extracellular signal molecules called autoinducers (AIs). To identify AI-regulated target genes in Vibrio cholerae El Tor (V. cholerae El), the strain responsible for the current cholera pandemic, luciferase expression was assayed in an AI− strain carrying a random lux transcriptional reporter library in the presence and absence of exogenously added AIs. Twenty-three genes were identified and shown to require the QS transcription factor, HapR, for their regulation. Several of the QS-dependent target genes, annotated as encoding hypothetical proteins, in fact encode HD-GYP proteins, phosphodiesterases that degrade the intracellular second messenger cyclic dimeric GMP (c-di-GMP), which is important for controlling biofilm formation. Indeed, overexpression of a representative QS-activated HD-GYP protein in V. cholerae El reduced the intracellular concentration of c-di-GMP, which in turn decreased exopolysaccharide production and biofilm formation. The V. cholerae classical biotype (V. cholerae Cl), which caused previous cholera pandemics and is HapR−, controls c-di-GMP levels and biofilm formation by the VieA signaling pathway. We show that the VieA pathway is dispensable for biofilm formation in V. cholerae El but that restoring HapR in V. cholerae Cl reestablishes QS-dependent repression of exopolysaccharide production. Thus, different pandemic strains of V. cholerae modulate c-di-GMP levels and control biofilm formation in response to distinct sensory pathways.

scholarly journals Fungal Exopolysaccharide: Production, Composition and Applications

2013 ◽  
Vol 6 ◽  
pp. MBI.S10957 ◽  
Author(s):  
Subhadip Mahapatra ◽  
Debdulal Banerjee
Keyword(s):  
Molecular Weight ◽  
Culture Medium ◽  
Medium Composition ◽  
General Outline ◽  
Exopolysaccharide Production ◽  
Fungal Strains ◽  
Physical Conditions ◽  
Extensive Search ◽  
Production Composition

Fungal exopolysaccharides (EPSs) have been recognized as high value biomacromolecules for the last two decades. These products, including pullulan, scleroglucan, and botryosphaeran, have several applications in industries, pharmaceuticals, medicine, foods etc. Although fungal EPSs are highly relevant, to date information concerning fungal biosynthesis is scarce and an extensive search for new fugal species that can produce novel EPSs is still needed. In most cases, the molecular weight variations and sugar compositions of fungal EPSs are dependent to culture medium composition and different physical conditions provided during fermentation. An inclusive and illustrative review on fungal EPS is presented here. The general outline of the present work includes fungal EPS production, their compositions and applications. An emphasis is also given to listing out different fungal strains that can produce EPSs.

scholarly journals Impact of Environmental and Genetic Factors on Biofilm Formation by the Probiotic Strain Lactobacillus rhamnosus GG

2007 ◽  
Vol 73 (21) ◽  
pp. 6768-6775 ◽  
Author(s):  
Sarah Lebeer ◽  
Tine L. A. Verhoeven ◽  
M�nica Perea V�lez ◽  
Jos Vanderleyden ◽  
Sigrid C. J. De Keersmaecker
Keyword(s):  
Biofilm Formation ◽  
Culture Medium ◽  
Lactobacillus Rhamnosus ◽  
Probiotic Strain ◽  
Lipoteichoic Acid ◽  
Microtiter Plate ◽  
Phenotypic Analysis ◽  
Lactobacillus Rhamnosus Gg ◽  
Abiotic Surfaces

ABSTRACTLactobacillus rhamnosusGG (ATCC 53103) is one of the clinically best-studied probiotic organisms. Moreover,L. rhamnosusGG displays very good in vitro adherence to epithelial cells and mucus. Here, we report thatL. rhamnosusGG is able to form biofilms on abiotic surfaces, in contrast to other strains of theLactobacillus caseigroup tested under the same conditions. Microtiter plate biofilm assays indicated that in vitro biofilm formation byL. rhamnosusGG is strongly modulated by culture medium factors and conditions related to the gastrointestinal environment, including low pH; high osmolarity; and the presence of bile, mucins, and nondigestible polysaccharides. Additionally, phenotypic analysis of mutants affected in exopolysaccharides (wzb), lipoteichoic acid (dltD), and central metabolism (luxS) showed their relative importance in biofilm formation byL. rhamnosusGG.

scholarly journals 2,3-Butanediol Synthesis and the Emergence of the Vibrio cholerae El Tor Biotype

2006 ◽  
Vol 74 (12) ◽  
pp. 6547-6556 ◽  
Author(s):  
Sang Sun Yoon ◽  
John J. Mekalanos
Keyword(s):  
Vibrio Cholerae ◽  
Diarrheal Disease ◽  
Sharp Decrease ◽  
Aquatic Environments ◽  
Environmental Niche ◽  
Medium Ph ◽  
Toxigenic Strains ◽  
El Tor ◽  
By Products ◽  
Evolutionary Fitness

ABSTRACT Vibrio cholerae is an aquatic bacterium that causes the severe diarrheal disease cholera. V. cholerae strains of the O1 serogroup exist as two biotypes, classical and El Tor. Toxigenic strains of the El Tor biotype emerged to cause the seventh pandemic of cholera in 1961 and subsequently displaced strains of the classical biotype both in the environment and as a cause of cholera within a decade. The factors that drove emergence of the El Tor biotype and the displacement of the classical biotype are unknown. Here, we show a unique difference in carbohydrate metabolism between these two biotypes. When grown with added carbohydrates, classical biotype strains generated a sharp decrease in medium pH, resulting in loss of viability. However, growth of El Tor biotype strain N16961 was enhanced due to its ability to produce 2,3-butanediol, a neutral fermentation end product, and suppress the accumulation of organic acids. An N16961 mutant (SSY01) defective in 2,3-butanediol synthesis showed the same defect in growth that classical biotype strains show in media rich in carbohydrates. Importantly, the SSY01 mutant was attenuated in its ability to colonize the intestines of infant mice, suggesting that host carbohydrates may be available to V. cholerae within the intestinal environment. Similarly, the SSY01 mutant failed to develop biofilms when utilizing N-acetyl-d-glucosamine as a carbon source. Because growth on N-acetyl-d-glucosamine likely reflects the ability of a strain to grow on chitin in certain aquatic environments, we conclude that the strains of classical biotype are likely defective compared to those of El Tor in growth in any environmental niche that is rich in chitin and/or other metabolizable carbohydrates. We propose that the ability to metabolize sugars without production of acid by-products might account for the improved evolutionary fitness of the V. cholerae El Tor biotype compared to that of the classical biotype both as a global cause of cholera and as an environmental organism.

scholarly journals Features of the Biological Properties of Vibrio cholerae Isolated during the Monitoring of Water Bodies in Rostov-on-Don from 1989 to 2018

2021 ◽  
pp. 148-151
Author(s):  
M. I. Ezhova ◽  
D. А. Levchenkо ◽  
I. V. Arkhangelskaya ◽  
V. D. Kruglikov ◽  
N. B. Nepomnyashchaya
Keyword(s):  
Environmental Protection ◽  
Vibrio Cholerae ◽  
Statistical Methods ◽  
Direct Relationship ◽  
Biological Properties ◽  
Biological Characteristics ◽  
Water Bodies ◽  
Environmental Objects ◽  
Toxigenic Strains ◽  
El Tor

The goal is to study the features of the biological properties of Vibrio cholerae strains found in environmental objects (EO) on the territory of Rostov-on-Don from 1989 to 2018.Materials and methods. Bacteriological, molecular biological and statistical methods were used to study 73 strains of cholera vibrios O1, O139 and 1702 strains of nonO1/nonO139 serogroups isolated over a 30-year period.Results and discussion. It was found that in Rostovon-Don, 78.0 % of toxigenic strains were isolated from all isolated from environmental protection in Russia, among which 2 were genetically unchanged. The V. cholerae O1 classical strain and 72 V. cholerae El Tor strains were found, of which 70 % belonged to the Ogawa serovar, and 3 % of the nontoxigenic strains were susceptible to the classical phage. A “very weak direct relationship” was statistically revealed between the isolation of V. cholerae O1, O139 and V. cholerae nonO1/nonO139 strains, in which the dominant serogroups (O67, O76, O75, O53, O16) were identified, and 18 % of the strains showed atypical agglutinability. Revealing the biological characteristics of V. cholerae strains contributes to the optimization of monitoring studies.

scholarly journals RS1 Satellite Phage Promotes Diversity of Toxigenic Vibrio cholerae by Driving CTX Prophage Loss and Elimination of Lysogenic Immunity

2014 ◽  
Vol 82 (9) ◽  
pp. 3636-3643 ◽  
Author(s):  
M. Kamruzzaman ◽  
William Paul Robins ◽  
S. M. Nayeemul Bari ◽  
Shamsun Nahar ◽  
John J. Mekalanos ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Sub Saharan Africa ◽  
Host Cells ◽  
Adult Rabbit ◽  
Content Type ◽  
Rabbit Intestine ◽  
Sub Saharan ◽  
Toxigenic Strains ◽  
Ctx Prophage ◽  
El Tor

ABSTRACTIn El Tor biotype strains of toxigenicVibrio cholerae, the CTXϕ prophage often resides adjacent to a chromosomally integrated satellite phage genome, RS1, which produces RS1ϕ particles by using CTX prophage-encoded morphogenesis proteins. RS1 encodes RstC, an antirepressor against the CTXϕ repressor RstR, which cooperates with the host-encoded LexA protein to maintain CTXϕ lysogeny. We found that superinfection of toxigenic El Tor strains with RS1ϕ, followed by inoculation of the transductants into the adult rabbit intestine, caused elimination of the resident CTX prophage-producing nontoxigenic derivatives at a high frequency. Further studies usingrecAdeletion mutants and a clonedrstCgene showed that the excision event wasrecAdependent and that introduction of additional copies of the clonedrstCgene instead of infection with RS1ϕ was sufficient to enhance CTXϕ elimination. Our data suggest that once it is excised from the chromosome, the elimination of CTX prophage from host cells is driven by the inability to reestablish CTXϕ lysogeny while RstC is overexpressed. However, with eventual loss of the additional copies ofrstC, the nontoxigenic derivatives can act as precursors of new toxigenic strains by acquiring the CTX prophage either through reinfection with CTXϕ or by chitin-induced transformation. These results provide new insights into the role of RS1ϕ inV. choleraeevolution and the emergence of highly pathogenic clones, such as the variant strains associated with recent devastating epidemics of cholera in Asia, sub-Saharan Africa, and Haiti.

scholarly journals Construction and Evaluation of a Safe, Live, Oral Vibrio cholerae Vaccine Candidate, IEM108

2003 ◽  
Vol 71 (10) ◽  
pp. 5498-5504 ◽  
Author(s):  
Weili Liang ◽  
Shixia Wang ◽  
Fenggang Yu ◽  
Lijuan Zhang ◽  
Guoming Qi ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Protective Antigen ◽  
Vaccine Candidate ◽  
Rabbit Model ◽  
Housekeeping Gene ◽  
Cholera Vaccine ◽  
Oral Cholera Vaccine ◽  
Toxigenic Strains ◽  
El Tor ◽  
Full Protection

ABSTRACT IEM101, a Vibrio cholerae O1 El Tor Ogawa strain naturally deficient in CTXΦ, was previously selected as a live cholera vaccine candidate. To make a better and safer vaccine that can induce protective immunity against both the bacteria and cholera toxin (CT), a new vaccine candidate, IEM108, was constructed by introducing a ctxB gene and an El Tor-derived rstR gene into IEM101. The ctxB gene codes for the protective antigen CTB subunit, and the rstR gene mediates phage immunity. The stable expression of the two genes was managed by a chromosome-plasmid lethal balanced system based on the housekeeping gene thyA. Immunization studies indicate that IEM108 generates good immune responses against both the bacteria and CT. After a single-dose intraintestinal vaccination with 109 CFU of IEM108, both anti-CTB immunoglobulin G and vibriocidal antibodies were detected in the immunized-rabbit sera. However, only vibriocidal antibodies are detected in rabbits immunized with IEM101. In addition, IEM108 but not IEM101 conferred full protection against the challenges of four wild-type toxigenic strains of V. cholerae O1 and 4 μg of CT protein in a rabbit model. By introducing the rstR gene, the frequency of conjugative transfer of a recombinant El Tor-derived RS2 suicidal plasmid to IEM108 was decreased 100-fold compared to that for IEM101. This indicated that the El Tor-derived rstR cloned in IEM108 was fully functional and could effectively inhibit the El Tor-derived CTXΦ from infecting IEM108. Our results demonstrate that IEM108 is an efficient and safe live oral cholera vaccine candidate that induces antibacterial and antitoxic immunity and CTXΦ phage immunity.

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