scholarly journals Genetic Relationships of Vibrio parahaemolyticus Isolates from Clinical, Human Carrier, and Environmental Sources in Thailand, Determined by Multilocus Sequence Analysis

2013 ◽  
Vol 79 (7) ◽  
pp. 2358-2370 ◽  
Author(s):  
Chonchanok Theethakaew ◽  
Edward J. Feil ◽  
Santiago Castillo-Ramírez ◽  
David M. Aanensen ◽  
Orasa Suthienkul ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Vibrio Parahaemolyticus ◽  
Genetic Relationships ◽  
Multilocus Sequence Analysis ◽  
Clinical Samples ◽  
Intragenic Recombination ◽  
Healthy Human ◽  
Content Type ◽  
Source Of Infection ◽  
Frozen Shrimp

ABSTRACTVibrio parahaemolyticusis a seafood-borne pathogenic bacterium that is a major cause of gastroenteritis worldwide. We investigated the genetic and evolutionary relationships of 101V. parahaemolyticusisolates originating from clinical, human carrier, and various environmental and seafood production sources in Thailand using multilocus sequence analysis. The isolates were recovered from clinical samples (n= 15), healthy human carriers (n= 18), various types of fresh seafood (n= 18), frozen shrimp (n= 16), fresh-farmed shrimp tissue (n= 18), and shrimp farm water (n= 16). Phylogenetic analysis revealed a high degree of genetic diversity within theV. parahaemolyticuspopulation, although isolates recovered from clinical samples and from farmed shrimp and water samples represented distinct clusters. The tight clustering of the clinical isolates suggests that disease-causing isolates are not a random sample of the environmental reservoir, although the source of infection remains unclear. Extensive serotypic diversity occurred among isolates representing the same sequence types and recovered from the same source at the same time. These findings suggest that the O- and K-antigen-encoding loci are subject to exceptionally high rates of recombination. There was also strong evidence of interspecies horizontal gene transfer and intragenic recombination involving therecAlocus in a large proportion of isolates. As the majority of the intragenic recombinational exchanges involvingrecAoccurred among clinical and carrier isolates, it is possible that the human intestinal tract serves as a potential reservoir of donor and recipient strains that is promoting horizontal DNA transfer, driving evolutionary change, and leading to the emergence of new, potentially pathogenic strains.

scholarly journals Multilocus Sequence Analysis of Phylogroup 1 and 2 Oral Treponeme Strains

2016 ◽  
Vol 83 (3) ◽  
Author(s):  
Yong-Biao Huo ◽  
Yuki Chan ◽  
Donnabella C. Lacap-Bugler ◽  
Sisu Mo ◽  
Patrick C. Y. Woo ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
16S Rrna ◽  
Periodontal Diseases ◽  
Genetic Relationships ◽  
Species Level ◽  
Multilocus Sequence Analysis ◽  
Species Differentiation ◽  
Treponema Denticola ◽  
Rrna Gene ◽  
Content Type

ABSTRACT More than 75 “species-level” phylotypes of spirochete bacteria belonging to the genus Treponema reside within the human oral cavity. The majority of these oral treponeme phylotypes correspond to as-yet-uncultivated taxa or strains of uncertain standing in taxonomy. Here, we analyze phylogenetic and taxonomic relationships between oral treponeme strains using a multilocus sequence analysis (MLSA) scheme based on the highly conserved 16S rRNA, pyrH, recA, and flaA genes. We utilized this MLSA scheme to analyze genetic data from a curated collection of oral treponeme strains (n = 71) of diverse geographical origins. This comprises phylogroup 1 (n = 23) and phylogroup 2 (n = 48) treponeme strains, including all relevant American Type Culture Collection reference strains. The taxonomy of all strains was confirmed or inferred via the analysis of ca. 1,450-bp 16S rRNA gene sequences using a combination of bioinformatic and phylogenetic approaches. Taxonomic and phylogenetic relationships between the respective treponeme strains were further investigated by analyzing individual and concatenated flaA (1,074-nucleotide [nt]), recA (1,377-nt), and pyrH (696-nt) gene sequence data sets. Our data confirmed the species differentiation between Treponema denticola (n = 41) and Treponema putidum (n = 7) strains. Notably, our results clearly supported the differentiation of the 23 phylogroup 1 treponeme strains into five distinct “species-level” phylotypes. These respectively corresponded to “Treponema vincentii” (n = 11), Treponema medium (n = 1), “Treponema sinensis” (Treponema sp. IA; n = 4), Treponema sp. IB (n = 3), and Treponema sp. IC (n = 4). In conclusion, our MLSA-based approach can be used to effectively discriminate oral treponeme taxa, confirm taxonomic assignment, and enable the delineation of species boundaries with high confidence. IMPORTANCE Periodontal diseases are caused by persistent polymicrobial biofilm infections of the gums and underlying tooth-supporting structures and have a complex and variable etiology. Although Treponema denticola is strongly associated with periodontal diseases, the etiological roles of other treponeme species/phylotypes are less well defined. This is due to a paucity of formal species descriptions and a poor understanding of genetic relationships between oral treponeme taxa. Our study directly addresses these issues. It represents one of the most comprehensive analyses of oral treponeme strains performed to date, including isolates from North America, Europe, and Asia. We envisage that our results will greatly facilitate future metagenomic efforts aimed at characterizing the clinical distributions of oral treponeme species/phylotypes, helping investigators to establish a more detailed understanding of their etiological roles in periodontal diseases and other infectious diseases. Our results are also directly relevant to various polymicrobial tissue infections in animals, which also involve treponeme populations.

scholarly journals Differentiation of Xylella fastidiosa Strains via Multilocus Sequence Analysis of Environmentally Mediated Genes (MLSA-E)

2011 ◽  
Vol 78 (5) ◽  
pp. 1385-1396 ◽  
Author(s):  
Jennifer K. Parker ◽  
Justin C. Havird ◽  
Leonardo De La Fuente
Keyword(s):  
Sequence Analysis ◽  
Genetic Variability ◽  
Xylella Fastidiosa ◽  
Genetic Relationships ◽  
Phylogenetic Analyses ◽  
Housekeeping Genes ◽  
The United States ◽  
Multilocus Sequence Analysis ◽  
Biological Traits ◽  
Content Type

ABSTRACTIsolates of the plant pathogenXylella fastidiosaare genetically very similar, but studies on their biological traits have indicated differences in virulence and infection symptomatology. Taxonomic analyses have identified several subspecies, and phylogenetic analyses of housekeeping genes have shown broad host-based genetic differences; however, results are still inconclusive for genetic differentiation of isolates within subspecies. This study employs multilocus sequence analysis of environmentally mediated genes (MLSA-E; genes influenced by environmental factors) to investigateX. fastidiosarelationships and differentiate isolates with low genetic variability. Potential environmentally mediated genes, including host colonization and survival genes related to infection establishment, were identifieda priori. The ratio of the rate of nonsynonymous substitutions to the rate of synonymous substitutions (dN/dS) was calculated to select genes that may be under increased positive selection compared to previously studied housekeeping genes. Nine genes were sequenced from 54X. fastidiosaisolates infecting different host plants across the United States. Results of maximum likelihood (ML) and Bayesian phylogenetic (BP) analyses are in agreement with knownX. fastidiosasubspecies clades but show novel within-subspecies differentiation, including geographic differentiation, and provide additional information regarding host-based isolate variation and specificity.dN/dSratios of environmentally mediated genes, though <1 due to high sequence similarity, are significantly greater than housekeeping genedN/dSratios and correlate with increased sequence variability. MLSA-E can more precisely resolve relationships between closely related bacterial strains with low genetic variability, such asX. fastidiosaisolates. Discovering the genetic relationships betweenX. fastidiosaisolates will provide new insights into the epidemiology of populations ofX. fastidiosa, allowing improved disease management in economically important crops.

scholarly journals Influence of Seasonality on the Genetic Diversity of Vibrio parahaemolyticus in New Hampshire Shellfish Waters as Determined by Multilocus Sequence Analysis

2012 ◽  
Vol 78 (10) ◽  
pp. 3778-3782 ◽  
Author(s):  
Crystal N. Ellis ◽  
Brian M. Schuster ◽  
Megan J. Striplin ◽  
Stephen H. Jones ◽  
Cheryl A. Whistler ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sequence Analysis ◽  
Genetic Analysis ◽  
New Hampshire ◽  
Environmental Conditions ◽  
Vibrio Parahaemolyticus ◽  
Multilocus Sequence Analysis ◽  
Content Type ◽  
High Level

ABSTRACTRisk of gastric infection withVibrio parahaemolyticusincreases with favorable environmental conditions and population shifts that increase prevalence of infective strains. Genetic analysis of New Hampshire strains revealed a unique population with some isolates similar to outbreak-causing strains and high-level diversity that increased as waters warmed.

scholarly journals Multilocus Sequence Analysis of the Marine Bacterial Genus Tenacibaculum Suggests Parallel Evolution of Fish Pathogenicity and Endemic Colonization of Aquaculture Systems

2014 ◽  
Vol 80 (17) ◽  
pp. 5503-5514 ◽  
Author(s):  
Christophe Habib ◽  
Armel Houel ◽  
Aurélie Lunazzi ◽  
Jean-François Bernardet ◽  
Anne Berit Olsen ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Parallel Evolution ◽  
Phylogenetic Reconstruction ◽  
Multilocus Sequence Analysis ◽  
Fish Pathogens ◽  
Long Distance ◽  
Marine Aquaculture ◽  
Content Type ◽  
The Family ◽  
Cohesive Group

ABSTRACTThe genusTenacibaculum, a member of the familyFlavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogenTenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the speciesT. maritimumconstitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoringTenacibaculuminfections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related toT. dicentrarchi, a recently described species.

scholarly journals Pulsed-Field Gel Electrophoresis and PCR Characterization of Environmental Vibrio parahaemolyticus Strains of Different Origins

2011 ◽  
Vol 77 (17) ◽  
pp. 6301-6304 ◽  
Author(s):  
E. Suffredini ◽  
C. Lopez-Joven ◽  
L. Maddalena ◽  
L. Croci ◽  
A. Roque
Keyword(s):  
Gel Electrophoresis ◽  
Vibrio Parahaemolyticus ◽  
Genetic Relationships ◽  
Pulsed Field Gel Electrophoresis ◽  
Environmental Isolates ◽  
Content Type ◽  
Pulsed Field ◽  
Intraspecies Variability ◽  
Different Origins

ABSTRACTThe present study used pulsed-field gel electrophoresis (PFGE) characterization to examine the intraspecies variability and genetic relationships among environmental isolates ofVibrio parahaemolyticusfrom different European countries. This is first study performed on environmentalV. parahaemolyticusthat included more than one European country.

scholarly journals Multilocus Sequence Analysis of Xanthomonads Causing Bacterial Spot of Tomato and Pepper Plants Reveals Strains Generated by Recombination among Species and Recent Global Spread of Xanthomonas gardneri

2014 ◽  
Vol 81 (4) ◽  
pp. 1520-1529 ◽  
Author(s):  
Sujan Timilsina ◽  
Mustafa O. Jibrin ◽  
Neha Potnis ◽  
Gerald V. Minsavage ◽  
Misrak Kebede ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sequence Analysis ◽  
Housekeeping Genes ◽  
Global Distribution ◽  
Multilocus Sequence Analysis ◽  
Regional Differentiation ◽  
Bacterial Spot ◽  
Content Type ◽  
Global Spread ◽  
Pathogen Populations

ABSTRACTFourXanthomonasspecies are known to cause bacterial spot of tomato and pepper, but the global distribution and genetic diversity of these species are not well understood. A collection of bacterial spot-causing strains from the Americas, Africa, Southeast Asia, and New Zealand were characterized for genetic diversity and phylogenetic relationships using multilocus sequence analysis of six housekeeping genes. By examining strains from different continents, we found unexpected phylogeographic patterns, including the global distribution of a single multilocus haplotype ofX. gardneri, possible regional differentiation inX. vesicatoria, and high species diversity on tomato in Africa. In addition, we found evidence of multiple recombination events betweenX. euvesicatoriaandX. perforans.Our results indicate that there have been shifts in the species composition of bacterial spot pathogen populations due to the global spread of dominant genotypes and that recombination between species has generated genetic diversity in these populations.

scholarly journals Multilocus sequence analysis and comparative evolution of virulence-associated genes and housekeeping genes of Clostridium difficile

Microbiology ◽  
2005 ◽  
Vol 151 (10) ◽  
pp. 3171-3180 ◽  
Author(s):  
Ludovic Lemée ◽  
Ingrid Bourgeois ◽  
Elodie Ruffin ◽  
Anne Collignon ◽  
Jean-François Lemeland ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Clostridium Difficile ◽  
Genetic Relationships ◽  
Housekeeping Genes ◽  
Multilocus Sequence Analysis ◽  
Binary Toxin ◽  
Toxin A ◽  
Toxin Genes ◽  
Colonization Factor ◽  
Clonal Population Structure

A multilocus sequence analysis of ten virulence-associated genes was performed to study the genetic relationships between 29 Clostridium difficile isolates of various origins, hosts and clinical presentations, and selected from the main lineages previously defined by multilocus sequence typing (MLST) of housekeeping genes. Colonization-factor-encoding genes (cwp66, cwp84, fbp68, fliC, fliD, groEL and slpA), toxin A and B genes (tcdA and tcdB), and the toxin A and B positive regulator gene (tcdD) were investigated. Binary toxin genes (cdtA and cdtB) were also detected, and internal fragments were sequenced for positive isolates. Virulence-associated genes exhibited a moderate polymorphism, comparable to the polymorphism of housekeeping genes, whereas cwp66 and slpA genes appeared highly polymorphic. Isolates recovered from human pseudomembranous colitis cases did not define a specific lineage. The presence of binary toxin genes, detected in five of the 29 isolates (17 %), was also not linked to clinical presentation. Conversely, toxigenic A−B+ isolates defined a very homogeneous lineage, which is distantly related to other isolates. By clustering analysis, animal isolates were intermixed with human isolates. Multilocus sequence analysis of virulence-associated genes is consistent with a clonal population structure for C. difficile and with the lack of host specificity. The data suggest a co-evolution of several of the virulence-associated genes studied (including toxins A and B and the binary toxin genes) with housekeeping genes, reflecting the genetic background of C. difficile, whereas flagellin, cwp66 and slpA genes may undergo recombination events and/or environmental selective pressure.

scholarly journals Veillonella seminalis sp. nov., a novel anaerobic Gram-stain-negative coccus from human clinical samples, and emended description of the genus Veillonella

2014 ◽  
Vol 64 (Pt_10) ◽  
pp. 3526-3531 ◽  
Author(s):  
Fabien Aujoulat ◽  
Philippe Bouvet ◽  
Estelle Jumas-Bilak ◽  
Hélène Jean-Pierre ◽  
Hélène Marchandin
Keyword(s):  
Sequence Analysis ◽  
16S Rrna ◽  
Type Strain ◽  
Type Species ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Gram Stain ◽  
Content Type ◽  
Link Type ◽  
Emended Description

Ten isolates of unknown, Gram-stain-negative, anaerobic cocci were recovered from human clinical samples, mainly from semen. On the basis of their phenotypic features, including morphology, main metabolic end products, gas production, nitrate reduction and decarboxylation of succinate, the strains were identified as members of the genus Veillonella. Multi-locus sequence analysis and corresponding phylogenies were based on 16S rRNA, dnaK and rpoB genes, and on the newly proposed gltA gene. The strains shared high levels of genetic sequence similarity and were related most closely to Veillonella ratti . The strains could not be differentiated from V. ratti on the basis of 16S rRNA gene sequence analysis while gltA, rpoB and dnaK gene sequences showed 85.1, 93.5 and 90.2 % similarity with those of the type strain of V. ratti , respectively. Phylogenetic analyses revealed that the isolates formed a robust clade in the V. ratti – Veillonella criceti – Veillonella magna subgroup of the genus Veillonella . As observed for V. criceti , the isolates were able to ferment fructose. In contrast to other members of the genus Veillonella , the 10 strains were not able to metabolize lactate. Cellular fatty acid composition was consistent with that of other species of the genus Veillonella . From these data, the 10 isolates are considered to belong to a novel species in the genus Veillonella , for which the name Veillonella seminalis sp. nov. is proposed. The type strain is ADV 4313.2T ( = CIP 107810T = LMG 28162T). Veillonella strain ACS-216-V-Col6b subjected to whole genome sequencing as part as the Human Microbiome Project is another representative of V. seminalis sp. nov. An emended description of the genus Veillonella is also proposed.

scholarly journals Population Structure of Clinical Vibrio parahaemolyticus from 17 Coastal Countries, Determined through Multilocus Sequence Analysis

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107371 ◽  
Author(s):  
Dongsheng Han ◽  
Hui Tang ◽  
Jun Lu ◽  
Guangzhou Wang ◽  
Lin Zhou ◽  
...  
Keyword(s):  
Population Structure ◽  
Sequence Analysis ◽  
Vibrio Parahaemolyticus ◽  
Multilocus Sequence Analysis

scholarly journals Draft Genome Sequence of Neisseria mucosa Strain HSUH001, Isolated from an Aggressive Periodontal Lesion

2021 ◽  
Vol 10 (19) ◽  
Author(s):  
Masatoshi Yamashita ◽  
Toshiyuki Nagasawa ◽  
Satsuki Kato ◽  
Hiroshi Miyakawa ◽  
Mari Fujita ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Multilocus Sequence Analysis ◽  
Content Type ◽  
Total Length ◽  
Neisseria Mucosa

ABSTRACT We report the draft genome sequence (143 contigs, with a total length of 2,424,805 bp and an N50 value of 36,066 bp) of a bacterium isolated from an aggressive periodontal lesion in a patient. We assigned strain HSUH001 to Neisseria mucosa through a multilocus sequence analysis.

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