scholarly journals A Comparative Genomics, Network-Based Approach to Understanding Virulence in Vibrio cholerae

2009 ◽  
Vol 191 (20) ◽  
pp. 6262-6272 ◽  
Author(s):  
Jianying Gu ◽  
Yufeng Wang ◽  
Timothy Lilburn

ABSTRACT Our views of the genes that drive phenotypes have generally been built up one locus or operon at a time. However, a given phenotype, such as virulence, is a multilocus phenomenon. To gain a more comprehensive view of the genes and interactions underlying a phenotype, we propose an approach that incorporates information from comparative genomics and network biology and illustrate it by examining the virulence phenotype of Vibrio cholerae O1 El Tor N16961. We assessed the associations among the virulence-associated proteins from Vibrio cholerae and all the other proteins from this bacterium using a functional-association network map. In the context of this map, we were able to identify 262 proteins that are functionally linked to the virulence-associated genes more closely than is typical of the proteins in this strain and 240 proteins that are functionally linked to the virulence-associated proteins with a confidence score greater than 0.9. The roles of these genes were investigated using functional information from online data sources, comparative genomics, and the relationships shown by the protein association map. We also incorporated core proteome data from the family Vibrionaceae; 35% of the virulence-associated proteins have orthologs among the 1,822 orthologous groups of proteins in the core proteome, indicating that they may be dual-role virulence genes or encode functions that have value outside the human host. This approach is a valuable tool in searching for novel functional associations and in investigating the relationship between genotype and phenotype.

Author(s):  
Bibhuti Bhusan Pal ◽  
Smruti Ranjan Nayak ◽  
Ashish Kumar Nayak ◽  
Dipti Ranjan Behera ◽  
Swatishree Pany ◽  
...  

Abstract Cholera localized outbreaks/epidemics accounting for high morbidity and mortality have been reported in different years both from the coastal and tribal districts of Odisha. In the present study, the emergence and spread of two sequential cholera outbreaks reported in July to October 2012 from Rayagada and Kalahandi districts of Odisha was investigated. Environmental water samples from different sources and rectal swabs from diarrhoea patients were analysed for identification, antibiogram profiles and molecular studies using DMAMA-PCR assays. The pulsed field gel electrophoresis (PFGE) was done on some selected Vibrio cholerae O1 strains isolated from these cholera outbreak areas. Results showed 42% of rectal swabs and 2.3% of water samples collected from both the districts were positive for Vibrio cholerae O1 Ogawa biotype El Tor carrying both ctxB1 and ctxB7 genotypes. The common resistance profile of V. cholerae O1 strains was ampicillin, nalidixic acid, furazolidone and co-trimoxazole. The PFGE analysis on selected V. cholerae O1 strains of ctxB1 and ctxB7 genotypes showed three pulsotypes with 96% similarity matrix exhibiting the relationship with their respective water sources. Hence, continuous surveillance is highly essential to monitor the antibiogram profile and changing pattern of ctxB genotypes of V. cholerae O1 in this region.


2015 ◽  
Vol 198 (3) ◽  
pp. 578-590 ◽  
Author(s):  
Allison M. Box ◽  
Matthew J. McGuffie ◽  
Brendan J. O'Hara ◽  
Kimberley D. Seed

ABSTRACTThe classical and El Tor biotypes ofVibrio choleraeserogroup O1, the etiological agent of cholera, are responsible for the sixth and seventh (current) pandemics, respectively. A genomic island (GI), GI-24, previously identified in a classical biotype strain ofV. cholerae, is predicted to encode clustered regularly interspaced short palindromic repeat (CRISPR)-associated proteins (Cas proteins); however, experimental evidence in support of CRISPR activity inV. choleraehas not been documented. Here, we show that CRISPR-Cas is ubiquitous in strains of the classical biotype but excluded from strains of the El Tor biotype. We also providein silicoevidence to suggest that CRISPR-Cas actively contributes to phage resistance in classical strains. We demonstrate that transfer of GI-24 toV. choleraeEl Tor via natural transformation enables CRISPR-Cas-mediated resistance to bacteriophage CP-T1 under laboratory conditions. To elucidate the sequence requirements of this type I-E CRISPR-Cas system, we engineered a plasmid-based system allowing the directed targeting of a region of interest. Through screening for phage mutants that escape CRISPR-Cas-mediated resistance, we show that CRISPR targets must be accompanied by a 3′ TT protospacer-adjacent motif (PAM) for efficient interference. Finally, we demonstrate that efficient editing ofV. choleraelytic phage genomes can be performed by simultaneously introducing an editing template that allows homologous recombination and escape from CRISPR-Cas targeting.IMPORTANCECholera, caused by the facultative pathogenVibrio cholerae, remains a serious public health threat. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) provide prokaryotes with sequence-specific protection from invading nucleic acids, including bacteriophages. In this work, we show that one genomic feature differentiating sixth pandemic (classical biotype) strains from seventh pandemic (El Tor biotype) strains is the presence of a CRISPR-Cas system in the classical biotype. We demonstrate that the CRISPR-Cas system from a classical biotype strain can be transferred to aV. choleraeEl Tor biotype strain and that it is functional in providing resistance to phage infection. Finally, we show that this CRISPR-Cas system can be used as an efficient tool for the editing ofV. choleraelytic phage genomes.


2010 ◽  
Vol 192 (13) ◽  
pp. 3524-3533 ◽  
Author(s):  
Christopher J. Grim ◽  
Nur A. Hasan ◽  
Elisa Taviani ◽  
Bradd Haley ◽  
Jongsik Chun ◽  
...  

ABSTRACT The genomes of V ibrio cholerae O1 Matlab variant MJ-1236, Mozambique O1 El Tor variant B33, and altered O1 El Tor CIRS101 were sequenced. All three strains were found to belong to the phylocore group 1 clade of V. cholerae, which includes the 7th-pandemic O1 El Tor and serogroup O139 isolates, despite displaying certain characteristics of the classical biotype. All three strains were found to harbor a hybrid variant of CTXΦ and an integrative conjugative element (ICE), leading to their establishment as successful clinical clones and the displacement of prototypical O1 El Tor. The absence of strain- and group-specific genomic islands, some of which appear to be prophages and phage-like elements, seems to be the most likely factor in the recent establishment of dominance of V. cholerae CIRS101 over the other two hybrid strains.


2018 ◽  
Vol 60 ◽  
pp. 80-88 ◽  
Author(s):  
Liliya V. Mironova ◽  
Anna S. Gladkikh ◽  
Anna S. Ponomareva ◽  
Sergey I. Feranchuk ◽  
Nikita О. Bochalgin ◽  
...  

2013 ◽  
Vol 18 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Isabelle Albert ◽  
Dieter Ferring ◽  
Tom Michels

According to the intergenerational solidarity model, family members who share similar values about family obligations should have a closer relationship and support each other more than families with a lower value consensus. The present study first describes similarities and differences between two family generations (mothers and daughters) with respect to their adherence to family values and, second, examines patterns of relations between intergenerational consensus on family values, affectual solidarity, and functional solidarity in a sample of 51 mother-daughter dyads comprising N = 102 participants from Luxembourgish and Portuguese immigrant families living in the Grand Duchy of Luxembourg. Results showed a small generation gap in values of hierarchical gender roles, but an acculturation gap was found in Portuguese mother-daughter dyads regarding obligations toward the family. A higher mother-daughter value consensus was related to higher affectual solidarity of daughters toward their mothers but not vice versa. Whereas affection and value consensus both predicted support provided by daughters to their mothers, affection mediated the relationship between consensual solidarity and received maternal support. With regard to mothers, only affection predicted provided support for daughters, whereas mothers’ perception of received support from their daughters was predicted by value consensus and, in the case of Luxembourgish mothers, by affection toward daughters.


1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41


Think India ◽  
2013 ◽  
Vol 16 (3) ◽  
pp. 10-19
Author(s):  
Ang Bao

The objective of this paper is to find the relationship between family firms’ CSR engagement and their non-family member employees’ organisational identification. Drawing upon the existing literature on social identity theory, corporate social responsibility and family firms, the author proposes that family firms engage actively in CSR programs in a balanced manner to increase non-family member employees’ organisational identification. The findings of the research suggest that by developing and implementing balanced CSR programs, and actively getting engaged in CSR activities, family firms may help their non-family member employees better identify themselves with the firms. The article points out that due to unbalanced CSR resource allocation, family firms face the problem of inefficient CSR program implementation, and are suggested to switch alternatively to an improved scheme. Family firms may be advised to take corresponding steps to select right employees, communicate better with non-family member employees, use resources better and handle firms’ succession problems efficiently. The paper extends employees’ identification and CSR research into the family firm research domain and points out some drawbacks in family firms’ CSR resource allocation while formerly were seldom noticed.


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