scholarly journals Comparative Genomic Analysis Using Microarray Demonstrates a Strong Correlation between the Presence of the 80-Kilobase Pathogenicity Island and Pathogenicity in Kanagawa Phenomenon-Positive Vibrio parahaemolyticus Strains

2008 ◽  
Vol 76 (3) ◽  
pp. 1016-1023 ◽  
Author(s):  
Kaori Izutsu ◽  
Ken Kurokawa ◽  
Kosuke Tashiro ◽  
Satoru Kuhara ◽  
Tetsuya Hayashi ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Genomic Analysis ◽  
Pathogenicity Island ◽  
Gene Clusters ◽  
Comparative Genomic ◽  
Genetic Event ◽  
Thermostable Direct Hemolysin ◽  
The Difference ◽  
Pandemic Strains ◽  
Almost All

ABSTRACTVibrio parahaemolyticusis a gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Almost all of the clinicalV. parahaemolyticusisolates exhibit beta-type hemolysis on Wagatsuma agar, known as the Kanagawa phenomenon (KP). KP is induced by the thermostable direct hemolysin produced by the organism and has been considered a crucial marker to distinguish pathogenic strains from nonpathogenic ones. Since 1996, so-called “pandemic clones,” the majority of which belong to serotype O3:K6, have caused worldwide outbreaks of gastroenteritis. In this study, we used a DNA microarray constructed based on the genome sequence of a pandemicV. parahaemolyticusstrain, RIMD2210633, to examine the genomic composition of 22 strains ofV. parahaemolyticus, including both pathogenic (pandemic and nonpandemic) and nonpathogenic strains. More than 86% of the RIMD2210633 genes were conserved in all of the strains tested. Many variably present genes formed gene clusters on the genome of RIMD2210633 and were probably acquired through lateral gene transfer. At least 65 genes over 11 loci were specifically present in the pandemic strains compared with any of the nonpandemic strains, suggesting that the difference between pandemic and nonpandemic strains is not due to a simple genetic event. Only the genes in the 80-kb pathogenicity island (Vp-PAI) on chromosome II, including twotdhgenes and a set of genes for the type III secretion system, were detected only in the KP-positive pathogenic strains. These results strongly suggest that acquisition of this Vp-PAI was crucial for the emergence ofV. parahaemolyticusstrains that are pathogenic for humans.

scholarly journals Identification of a DNA Methyltransferase Gene Carried on a Pathogenicity Island-Like Element (VPAI) in Vibrio parahaemolyticus and Its Prevalence among Clinical and Environmental Isolates

2006 ◽  
Vol 72 (6) ◽  
pp. 4455-4460 ◽  
Author(s):  
Hui-zhen Wang ◽  
Minnie M. L. Wong ◽  
Desmond O'Toole ◽  
Mandy M. H. Mak ◽  
Rudolf S. S. Wu ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Dna Methyltransferase ◽  
Pathogenicity Island ◽  
Environmental Isolates ◽  
Virulence Traits ◽  
Hemolysin Gene ◽  
Methyltransferase Gene ◽  
Thermostable Direct Hemolysin ◽  
Pandemic Strains

ABSTRACT In this study we identified a putative virulence-associated DNA methyltransferase (MTase) gene carried on a novel 22.79-kb pathogenicity island-like element (VPAI) in V. parahaemolyticus. The V. parahaemolyticus MTase gene was shown by PCR to be prevalent (>98%) in pandemic thermostable direct hemolysin gene-positive isolates, which suggests that VPAI may confer unique virulence traits to pandemic strains of V. parahaemolyticus.

scholarly journals Genome Reduction and Secondary Metabolism of the Marine Sponge-Associated Cyanobacterium Leptothoe

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis
Keyword(s):  
Natural Products ◽  
Microbial Communities ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Marine Sponges ◽  
Genome Reduction ◽  
Extracellular Polysaccharides ◽  
Comparative Genomic ◽  
Symbiotic Relationships ◽  
Genes Encoding

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.

scholarly journals Comparative genomic analysis of Methanimicrococcus blatticola provides insights into host adaptation in archaea and the evolution of methanogenesis

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Courtney M. Thomas ◽  
Najwa Taib ◽  
Simonetta Gribaldo ◽  
Guillaume Borrel
Keyword(s):  
Gut Microbiota ◽  
Large Scale ◽  
Genomic Analysis ◽  
Host Adaptation ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Methyl Branch ◽  
Mechanisms Of Adaptation ◽  
Hydrogenotrophic Methanogens ◽  
Almost All

AbstractOther than the Methanobacteriales and Methanomassiliicoccales, the characteristics of archaea that inhabit the animal microbiome are largely unknown. Methanimicrococcus blatticola, a member of the Methanosarcinales, currently reunites two unique features within this order: it is a colonizer of the animal digestive tract and can only reduce methyl compounds with H2 for methanogenesis, a increasingly recognized metabolism in the archaea and whose origin remains debated. To understand the origin of these characteristics, we have carried out a large-scale comparative genomic analysis. We infer the loss of more than a thousand genes in M. blatticola, by far the largest genome reduction across all Methanosarcinales. These include numerous elements for sensing the environment and adapting to more stable gut conditions, as well as a significant remodeling of the cell surface components likely involved in host and gut microbiota interactions. Several of these modifications parallel those previously observed in phylogenetically distant archaea and bacteria from the animal microbiome, suggesting large-scale convergent mechanisms of adaptation to the gut. Strikingly, M. blatticola has lost almost all genes coding for the H4MPT methyl branch of the Wood–Ljungdahl pathway (to the exception of mer), a phenomenon never reported before in any member of Class I or Class II methanogens. The loss of this pathway illustrates one of the evolutionary processes that may have led to the emergence of methyl-reducing hydrogenotrophic methanogens, possibly linked to the colonization of organic-rich environments (including the animal gut) where both methyl compounds and hydrogen are abundant.

scholarly journals A database for risk assessment and comparative genomic analysis of foodborne Vibrio parahaemolyticus in China

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Rui Pang ◽  
Yanping Li ◽  
Moutong Chen ◽  
Haiyan Zeng ◽  
Tao Lei ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Foodborne Pathogens ◽  
Vibrio Parahaemolyticus ◽  
Foodborne Pathogen ◽  
Genomic Analysis ◽  
Food Samples ◽  
Comparative Genomic ◽  
Genome Database ◽  
Scientific Database ◽  
Need To Evaluate

Abstract Vibrio parahaemolyticus is a major foodborne pathogen worldwide. The increasing number of cases of V. parahaemolyticus infections in China indicates an urgent need to evaluate the prevalence and genetic diversity of this pathogenic bacterium. In this paper, we introduce the Foodborne Vibrio parahaemolyticus genome database (FVPGD), the first scientific database of foodborne V. parahaemolyticus distribution and genomic data in China, based on our previous investigations of V. parahaemolyticus contamination in different kinds of food samples across China from 2011 to 2016. The dataset includes records of 2,499 food samples and 643 V. parahaemolyticus strains from supermarkets and marketplaces distributed over 39 cities in China; 268 whole-genome sequences have been deposited in this database. A spatial view on the risk situations of V. parahaemolyticus contamination in different food types is provided. Additionally, the database provides a functional interface of sequence BLAST, core genome multilocus sequence typing, and phylogenetic analysis. The database will become a powerful tool for risk assessment and outbreak investigations of foodborne pathogens in China.

scholarly journals Insights into the cultured bacterial fraction of corals

2020 ◽  
Author(s):  
Michael Sweet ◽  
Helena Villela ◽  
Tina Keller-Costa ◽  
Rodrigo Costa ◽  
Stefano Romano ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Gene Clusters ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Comprehensive Overview ◽  
Associated Bacteria ◽  
Reef Restoration ◽  
Coral Holobiont ◽  
Metabolic Interactions ◽  
And Function

Abstract Bacteria associated with coral hosts are diverse and abundant, with recent studies suggesting involvement of these symbionts in host resilience to anthropogenic stress. Despite the putative importance of bacteria, the work dedicated to culturing coral-associated bacteria has received little attention. Combining published and unpublished data, here we report a comprehensive overview of the diversity and function of culturable, coral-associated bacteria. A total of 3055 isolates from 52 studies were considered by our meta-survey. Of these, 1045 had full length 16S rRNA gene sequences, spanning 138 formally described and 12 putatively novel bacterial genera across the Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria phyla. We performed comparative genomic analysis using the available genomes of 74 strains and identified potential signatures of beneficial bacterial-coral symbioses among them. Our analysis revealed >400 biosynthetic gene clusters that underlie the biosynthesis of antioxidant, antimicrobial, cytotoxic, and other secondary metabolites. Moreover, we uncovered genomic features - not previously described for coral-bacterial symbioses - involved in host colonization and host-symbiont recognition, antiviral defence mechanisms, and/or integrated metabolic interactions, which we suggest as novel targets for the screening of coral probiotics. Our results highlight the importance of bacterial cultures to elucidate coral holobiont functioning, and guide the selection of probiotic candidates to promote coral resilience and improve reef restoration efforts.

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