Multilocus sequence typing (MLST) analysis of 104Clostridium difficilestrains isolated from China

2012 ◽  
Vol 141 (1) ◽  
pp. 195-199 ◽  
Author(s):  
Q. YAN ◽  
J. ZHANG ◽  
C. CHEN ◽  
H. ZHOU ◽  
P. DU ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Clostridium Difficile ◽  
Multilocus Sequence Typing ◽  
Geographical Origin ◽  
Host Population ◽  
High Genetic Diversity ◽  
Dominant Type ◽  
Mlst Analysis ◽  
Phylogenetic Lineages ◽  
Sequence Types

SUMMARYThe phylogenetic and epidemic relationships of 104 clinical isolatesof Clostridium difficilefrom three hospitals of different geographical and population sources in China were investigated by multilocus sequence typing. Twenty-two sequence types (STs) were identified, four of which, ST117, ST118, ST119 and ST129, were novel. No geographically specific and host population-specific phylogenetic lineages were found and there was no correlation between geographical origin or host population and strain genotype. ST37 was the dominant type in our survey but the four novel STs underline the high genetic diversity and unique polymorphisms inC. difficilefrom China.

Multilocus sequence typing of 102 Burkholderia pseudomallei strains isolated from China

2016 ◽  
Vol 144 (9) ◽  
pp. 1917-1923 ◽  
Author(s):  
Y. FANG ◽  
P. ZHU ◽  
Q. LI ◽  
H. CHEN ◽  
Y. LI ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Burkholderia Pseudomallei ◽  
Arithmetic Mean ◽  
Host Population ◽  
Group Method ◽  
High Genetic Diversity ◽  
Pair Group ◽  
Strain Collection ◽  
Phylogenetic Lineages ◽  
Sequence Types

SUMMARYThe phylogenetic and epidemiological relationships of 102 Burkholderia pseudomallei clinical isolates from different geographical and population sources in China were investigated by multilocus sequence typing (MLST). The MLST data were analysed using the e-BURST algorithm, and an unweighted pair-group method with arithmetic mean dendrogram was constructed based on the pair-wise differences in the allelic profiles of the strains. Forty-one sequence types (STs) were identified, of which eight were novel (ST1341, ST1345, ST1346, ST1347, ST1348, ST1349, ST1350, ST1351). No geographical-specific or host population-specific phylogenetic lineages were identified. ST46, ST50, ST55, ST58, ST70 and ST1095 predominated, but ~44% of isolates were assigned to 45 STs illustrating high genetic diversity in the strain collection. Additionally, the phylogenetic relationships of the dominant STs in China showed significant linkeage with B. pseudomallei isolates from Thailand. Analysis of the gmhD allele suggests high genetic variation in B. pseudomallei in China.

scholarly journals High Genetic Diversity ofEnterococcus faeciumandEnterococcus faecalisClinical Isolates by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing from a Hospital in Malaysia

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Poh Leng Weng ◽  
Ramliza Ramli ◽  
Mariana Nor Shamsudin ◽  
Yoke-Kqueen Cheah ◽  
Rukman Awang Hamat
Keyword(s):  
Genetic Diversity ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Genetic Relatedness ◽  
Pulsed Field Gel Electrophoresis ◽  
High Genetic Diversity ◽  
Pulsed Field ◽  
Susceptibility Profiles ◽  
Sequence Types ◽  
Multiple Antibiotics

Little is known on the genetic relatedness and potential dissemination of particular enterococcal clones in Malaysia. We studied the antibiotic susceptibility profiles ofEnterococcus faeciumandEnterococcus faecalisand subjected them to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).E. faeciumandE. faecalisdisplayed 27 and 30 pulsotypes, respectively, and 10 representativeE. faeciumandE. faecalisisolates (five each) yielded few different sequence types (STs): ST17 (2 isolates), ST78, ST203, and ST601 forE. faecium, and ST6, ST16, ST28, ST179, and ST399 forE. faecalis. Resistance to tazobactam-piperacillin and ampicillin amongstE. faeciumisolates was highly observed as compared toE. faecalisisolates. All of the isolates were sensitive to vancomycin and teicoplanin. The presence of epidemic and nosocomial strains of selectedE. faeciumSTs: 17, 78, and 203 andE. faecalisST6 as well as high rates of resistance to multiple antibiotics amongstE. faeciumisolates is of a particular concern.

scholarly journals Genetic Diversity of Porphyromonas gingivalis Isolates Recovered from Single “Refractory” Periodontitis Sites

2008 ◽  
Vol 74 (18) ◽  
pp. 5817-5821 ◽  
Author(s):  
Morten Enersen ◽  
Ingar Olsen ◽  
Dominique A. Caugant
Keyword(s):  
Genetic Diversity ◽  
Porphyromonas Gingivalis ◽  
Multilocus Sequence Typing ◽  
Sequence Types

ABSTRACT Multilocus sequence typing and fimA genotyping were performed on Porphyromonas gingivalis isolates from 15 subjects with “refractory” periodontitis. Several sequence types were detected for most individual pockets. The variation indicated recombination at the recA and pepO genes. The prevalence of fimA genotypes II and IV confirmed their association with periodontitis.

scholarly journals Prevalence and Genetic Diversity of C. Jejuni Isolated from Broilers and their Environment Using flaA-RFLP Typing and MLST Analysis

2020 ◽  
Vol 20 (2) ◽  
pp. 485-501
Author(s):  
Viktorija Lėgaudaitė Lydekaitienė ◽  
E. Kudirkienė
Keyword(s):  
Genetic Diversity ◽  
Restriction Fragment Length Polymorphism ◽  
Campylobacter Jejuni ◽  
Length Polymorphism ◽  
Fragment Length Polymorphism ◽  
Wild Birds ◽  
Mlst Analysis ◽  
Sequence Types ◽  
Restriction Fragment Length ◽  
Rflp Typing

AbstractCampylobacter is highly diverse genetically and also undergoes frequent intraspecific recombination. A major source of campylobacteriosis, which is transmitted to humans is found in poultry. The assessment of the genetic diversity among Campylobacter population is critical to our understanding of the epidemiology. The genetic diversity of Campylobacter jejuni isolates in broilers and their environment were investigated by flaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). The study revealed that 92.3% of the examined broiler flocks were contaminated with Campylobacter spp. A total number of 35 different flaA types defined by flaA-RFLP were found in 448 C. jejuni isolates originated from broilers, litter, puddles, zones, anteroom and wild birds. The most dominant flaA type was XXV. MLST defined 20 sequence types (STs) belonging to 10 clonal complexes (CCs). Among all the STs 9 isolates (15%) were consigned to 2 different STs (ST-7413 and ST-4800), which could not be assigned. The most common CCs were ST-21 and ST-179. The ST-21 CC was common in broilers and environment (puddle water and concentric zones) and the ST-179 CC was specific to wild birds, but also was found in puddle water and concentric zones.

scholarly journals Diversity of cwp loci in clinical isolates of Clostridium difficile

2013 ◽  
Vol 62 (9) ◽  
pp. 1444-1452 ◽  
Author(s):  
Manuele Biazzo ◽  
Rossella Cioncada ◽  
Luigi Fiaschi ◽  
Vittorio Tedde ◽  
Patrizia Spigaglia ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Clostridium Difficile ◽  
Total Cell ◽  
The Other ◽  
Clinical Isolates ◽  
Cell Wall Proteins ◽  
High Genetic Diversity ◽  
Cell Extracts ◽  
Number Of Genes ◽  
Genes Encoding

An increased incidence of Clostridium difficile infection (CDI) is associated with the emergence of epidemic strains characterized by high genetic diversity. Among the factors that may have a role in CDI is a family of 29 paralogues, the cell-wall proteins (CWPs), which compose the outer layer of the bacterial cell and are likely to be involved in colonization. Previous studies have shown that 12 of the 29 cwp genes are clustered in the same region, named after slpA (cwp1), the slpA locus, whereas the remaining 17 paralogues are distributed throughout the genome. The variability of 14 of these 17 cwp paralogues was determined in 40 C. difficile clinical isolates belonging to six of the currently prevailing PCR ribotypes. Based on sequence conservation, these cwp genes were divided into two groups, one comprising nine cwp loci having highly conserved sequences in all isolates, and the other five loci showing low genetic conservation among isolates of the same PCR ribotype, as well as between different PCR ribotypes. Three conserved CWPs, Cwp16, Cwp18 and Cwp25, and two variable ones, Cwp26 and Cwp27, were characterized further by Western blot analysis of total cell extracts or surface-layer preparations of the C. difficile clinical isolates. Expression of genetically invariable CWPs was well conserved in all isolates, whilst genetically variable CWPs were not always expressed at comparable levels, even in strains containing identical sequences but belonging to different PCR ribotypes. This is the first report on the distribution and variability of a number of genes encoding CWPs in C. difficile.

scholarly journals High Genetic Diversity in Flavobacterium psychrophilum Isolates from Healthy Rainbow Trout (Oncorhynchus mykiss) Farmed in the Same Watershed, Revealed by Two Typing Methods

2020 ◽  
Vol 87 (2) ◽  
Author(s):  
Ségolène Calvez ◽  
Nora Navarro-Gonzalez ◽  
Charlène Siekoula-Nguedia ◽  
Catherine Fournel ◽  
Eric Duchaud
Keyword(s):  
Genetic Diversity ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Clonal Complex ◽  
Economic Losses ◽  
High Genetic Diversity ◽  
Content Type ◽  
Flavobacterium Psychrophilum ◽  
Sequence Types ◽  
Apparently Healthy

ABSTRACT Flavobacterium psychrophilum affects salmonid health worldwide and causes economic losses. The genetic diversity of the pathogen must be considered to develop control methods. However, previous studies have reported both high and low levels of genetic diversity. The present longitudinal study aimed at assessing the genetic diversity of F. psychrophilum at a small temporal and geographic scale. Four farms located on the same watershed in France were studied. Rainbow trout (Oncorhynchus mykiss) batches were monitored, and apparently healthy individuals were sampled over 1 year. A total of 288 isolates were recovered from fish organs (gills and spleen) and eggs. Pulsed field gel electrophoresis revealed high genetic diversity. Multilocus sequence typing performed on a selection of 31 isolates provided congruent results, as follows: 18 sequence types (STs) were found, of which 13 were novel. The mean gene diversity (H = 0.8413) was much higher than that previously reported for this host species, although the sampling was restricted to a single watershed and 1 year. Seven isolates out of 31 were assigned to clonal complex ST10 (CC-ST10), which is the predominant clonal complex in the main salmonid production areas. A split decomposition tree reflected a panmictic population. This finding is important for aquaculture veterinarians in their diagnostic procedure, as the choice of adequate antibiotic treatment is conditioned by the correct identification of the causative agent. Furthermore, this study expands our knowledge on genetic diversity required for the development of an effective vaccine against F. psychrophilum. IMPORTANCE The bacterium Flavobacterium psychrophilum is a serious pathogen in many fish species, especially salmonids, that is responsible for considerable economic losses worldwide. In order to treat infections and to develop vaccines, the genetic diversity of this bacterium needs to be known. We assessed the genetic diversity of F. psychrophilum isolates from apparently healthy rainbow trout raised in several fish farms in the same watershed in France. Two different genotyping methods revealed high diversity. The majority of isolates were unrelated to clonal complex sequence type 10 (CC-ST10), the clonal complex that is predominant worldwide and associated with disease in rainbow trout. In addition, we found 13 novel sequence types. These results suggest that a diverse subpopulation of F. psychrophilum may be harbored by rainbow trout.

Characterization of Neisseria meningitidis isolates collected from 1974 to 2003 in Japan by multilocus sequence typing

2004 ◽  
Vol 53 (7) ◽  
pp. 657-662 ◽  
Author(s):  
Hideyuki Takahashi ◽  
Toshiro Kuroki ◽  
Yuko Watanabe ◽  
Hiroshi Tanaka ◽  
Hiroo Inouye ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Neisseria Meningitidis ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
The Other ◽  
Mlst Database ◽  
Mlst Analysis ◽  
The Past ◽  
Sequence Types

Analysis of 182 Neisseria meningitidis strains isolated over the past 30 years in Japan by serogroup typing and multilocus sequence typing (MLST) was performed. The serogroups of the 182 Japanese isolates were B (103 isolates), Y (39), W135 (1) and non-groupable (39). By MLST analysis, 65 different sequence types (ST) were identified, 42 of which were not found in the MLST database as of January 2004 and seemed to be unique to Japan. Statistical analysis of the MLST results revealed that, although the Japanese isolates seemed to be genetically divergent, they were classified into six major clonal complexes and other minor complexes. Among these isolates, well-documented ST complexes found worldwide were present, such as ST-23 complex (49 isolates), ST-44 complex (41 isolates) and ST-32 complex (8 isolates). On the other hand, a new clonal complex designated ST-2046 complex (28 isolates), which has not been identified in other countries, was also found, suggesting that this clone was indigenous to Japan. Taken together, it was speculated that meningococcal isolates in Japan comprised heterogeneous clones, which were derived both from clones identified in other countries and clones unique to Japan.

scholarly journals Multilocus Sequence Typing Reveals Extensive Genetic Diversity of the Emerging Fungal Pathogen Scedosporium aurantiacum

2021 ◽  
Vol 11 ◽  
Author(s):  
Azian Harun ◽  
Alex Kan ◽  
Katharina Schwabenbauer ◽  
Felix Gilgado ◽  
Haybrig Perdomo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Cystic Fibrosis ◽  
Multilocus Sequence Typing ◽  
Fungal Pathogen ◽  
Fungal Colonization ◽  
Invasive Infection ◽  
Mlst Scheme ◽  
Australian Continent ◽  
The World ◽  
Sequence Types

Scedosporium spp. are the second most prevalent filamentous fungi after Aspergillus spp. recovered from cystic fibrosis (CF) patients in various regions of the world. Although invasive infection is uncommon prior to lung transplantation, fungal colonization may be a risk factor for invasive disease with attendant high mortality post-transplantation. Abundant in the environment, Scedosporium aurantiacum has emerged as an important fungal pathogen in a range of clinical settings. To investigate the population genetic structure of S. aurantiacum, a MultiLocus Sequence Typing (MLST) scheme was developed, screening 24 genetic loci for polymorphisms on a tester strain set. The six most polymorphic loci were selected to form the S. aurantiacum MLST scheme: actin (ACT), calmodulin (CAL), elongation factor-1α (EF1α), RNA polymerase subunit II (RPB2), manganese superoxide dismutase (SOD2), and β-tubulin (TUB). Among 188 global clinical, veterinary, and environmental strains, 5 to 18 variable sites per locus were revealed, resulting in 8 to 23 alleles per locus. MLST analysis observed a markedly high genetic diversity, reflected by 159 unique sequence types. Network analysis revealed a separation between Australian and non-Australian strains. Phylogenetic analysis showed two major clusters, indicating correlation with geographic origin. Linkage disequilibrium analysis revealed evidence of recombination. There was no clustering according to the source of the strains: clinical, veterinary, or environmental. The high diversity, especially amongst the Australian strains, suggests that S. aurantiacum may have originated within the Australian continent and was subsequently dispersed to other regions, as shown by the close phylogenetic relationships between some of the Australian sequence types and those found in other parts of the world. The MLST data are accessible at http://mlst.mycologylab.org. This is a joined publication of the ISHAM/ECMM working groups on “Scedosporium/Pseudallescheria Infections” and “Fungal Respiratory Infections in Cystic Fibrosis”.

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