scholarly journals Retrospective Study of Listeria Monocytogenes Isolated in the Territory of Inner Eurasia from 1947 to 1999

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 184 ◽  
Author(s):  
Psareva ◽  
Egorova ◽  
Liskova ◽  
Razheva ◽  
Gladkova ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Listeria Monocytogenes ◽  
20Th Century ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
Small Ruminants ◽  
Virulence Gene ◽  
Penicillin G ◽  
Allelic Variants ◽  
Mlst Scheme

Listeriosis is one of the most significant humans and animals foodborne infectious diseases. Here, we characterized 48 Listeria monocytogenes strains isolated in the territory of inner Eurasia during the second half of the 20th century. A total of 23 strains (52.3%) were susceptible to the nine antibiotics tested, 30.43%, 15.22%, and 8.7% were resistant penicillin G, ampicillin, and enrofloxacin, respectively. We applied the multilocus sequence typing (MLST) scheme to determine the phylogenetic positions of the strains. All but one strain belonged to the II phylogenetic lineage, and the majority of the strains belonged to one of the previously described clonal complexes (СCs). More than 60% of the strains belonged to the clonal complex CC7 that prevailed among all sources, including cattle (58%), small ruminants (64%), rodents (71%), and humans (50%). Further, CC7, CC101, and CC124 were found among human isolates. The MLST scheme was supplemented with virulence gene analysis. In total, eight inlA, six inlB, and six inlC allelic variants were found, and all but one strain carried one of the two inlE alleles. Most strains (62.5%) belonged to the same multivirulence locus sequence typing (MvLST) type, which includes CC7, inlA allele 4, inlB allele 14, inlC allele 6, and inlE allele 8.

scholarly journals Determination of Molecular Phylogenetics of Vibrio parahaemolyticus Strains by Multilocus Sequence Typing

2008 ◽  
Vol 190 (8) ◽  
pp. 2831-2840 ◽  
Author(s):  
Narjol González-Escalona ◽  
Jaime Martinez-Urtaza ◽  
Jaime Romero ◽  
Romilio T. Espejo ◽  
Lee-Ann Jaykus ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Multilocus Sequence Typing ◽  
Vibrio Parahaemolyticus ◽  
Molecular Phylogenetics ◽  
Clonal Complex ◽  
Housekeeping Genes ◽  
The United States ◽  
Health Concern ◽  
Mlst Scheme

ABSTRACT Vibrio parahaemolyticus is an important human pathogen whose transmission is associated with the consumption of contaminated seafood. There is a growing public health concern due to the emergence of a pandemic strain causing severe outbreaks worldwide. Many questions remain unanswered regarding the evolution and population structure of V. parahaemolyticus. In this work, we describe a multilocus sequence typing (MLST) scheme for V. parahaemolyticus based on the internal fragment sequences of seven housekeeping genes. This MLST scheme was applied to 100 V. parahaemolyticus strains isolated from geographically diverse clinical (n = 37) and environmental (n = 63) sources. The sequences obtained from this work were deposited and are available in a public database (http://pubmlst.org/vparahaemolyticus ). Sixty-two unique sequence types were identified, and most (50) were represented by a single isolate, suggesting a high level of genetic diversity. Three major clonal complexes were identified by eBURST analysis. Separate clonal complexes were observed for V. parahaemolyticus isolates originating from the Pacific and Gulf coasts of the United States, while a third clonal complex consisted of strains belonging to the pandemic clonal complex with worldwide distribution. The data reported in this study indicate that V. parahaemolyticus is genetically diverse with a semiclonal population structure and an epidemic structure similar to that of Vibrio cholerae. Genetic diversity in V. parahaemolyticus appears to be driven primarily by frequent recombination rather than mutation, with recombination ratios estimated at 2.5:1 and 8.8:1 by allele and site, respectively. Application of this MLST scheme to more V. parahaemolyticus strains and by different laboratories will facilitate production of a global picture of the epidemiology and evolution of this pathogen.

scholarly journals Novel Virulence Gene and Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) Multilocus Sequence Typing Scheme for Subtyping of the Major Serovars ofSalmonella entericasubsp.enterica

2011 ◽  
Vol 77 (6) ◽  
pp. 1946-1956 ◽  
Author(s):  
Fenyun Liu ◽  
Rodolphe Barrangou ◽  
Peter Gerner-Smidt ◽  
Efrain M. Ribot ◽  
Stephen J. Knabel ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Virulence Genes ◽  
Virulence Gene ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
The Novel ◽  
Important Food ◽  
Mlst Scheme ◽  
Food Borne ◽  
Short Palindromic Repeat

ABSTRACTSalmonella entericasubsp.entericais the leading cause of bacterial food-borne disease in the United States. Molecular subtyping methods are powerful tools for tracking the farm-to-fork spread of food-borne pathogens during outbreaks. In order to develop a novel multilocus sequence typing (MLST) scheme for subtyping the major serovars ofS. entericasubsp.enterica, the virulence genessseLandfimHand clustered regularly interspaced short palindromic repeat (CRISPR) loci were sequenced from 171 clinical isolates from nineSalmonellaserovars,Salmonellaserovars Typhimurium, Enteritidis, Newport, Heidelberg, Javiana, I 4,[5],12:i:−, Montevideo, Muenchen, and Saintpaul. The MLST scheme using only virulence genes was congruent with serotyping and identified epidemic clones but could not differentiate outbreaks. The addition of CRISPR sequences dramatically improved discriminatory power by differentiating individual outbreak strains/clones. Of particular note, the present MLST scheme provided better discrimination ofSalmonellaserovar Enteritidis strains than pulsed-field gel electrophoresis (PFGE). This method showed high epidemiologic concordance for all serovars screened except forSalmonellaserovar Muenchen. In conclusion, the novel MLST scheme described in the present study accurately differentiated outbreak strains/clones of the major serovars ofSalmonella, and therefore, it shows promise for subtyping this important food-borne pathogen during investigations of outbreaks.

scholarly journals Ruminant Rhombencephalitis-Associated Listeria monocytogenes Alleles Linked to a Multilocus Variable-Number Tandem-Repeat Analysis Complex

2011 ◽  
Vol 77 (23) ◽  
pp. 8325-8335 ◽  
Author(s):  
Lina Balandyté ◽  
Isabelle Brodard ◽  
Joachim Frey ◽  
Anna Oevermann ◽  
Carlos Abril
Keyword(s):  
Listeria Monocytogenes ◽  
Tandem Repeat ◽  
Genetic Relatedness ◽  
Clonal Complex ◽  
Variable Number Tandem Repeat ◽  
Virulence Gene ◽  
Variable Number ◽  
Content Type ◽  
Repeat Analysis ◽  
Cns Infections

ABSTRACTListeria monocytogenesis among the most important food-borne pathogens and is well adapted to persist in the environment. To gain insight into the genetic relatedness and potential virulence ofL. monocytogenesstrains causing central nervous system (CNS) infections, we used multilocus variable-number tandem-repeat analysis (MLVA) to subtype 183L. monocytogenesisolates, most from ruminant rhombencephalitis and some from human patients, food, and the environment. Allelic-profile-based comparisons groupedL. monocytogenesstrains mainly into three clonal complexes and linked single-locus variants (SLVs). Clonal complex A essentially consisted of isolates from human and ruminant brain samples. All but one rhombencephalitis isolate from cattle were located in clonal complex A. In contrast, food and environmental isolates mainly clustered into clonal complex C, and none was classified as clonal complex A. Isolates of the two main clonal complexes (A and C) obtained by MLVA were analyzed by PCR for the presence of 11 virulence-associated genes (prfA,actA,inlA,inlB,inlC,inlD,inlE,inlF,inlG,inlJ, andinlC2H). Virulence gene analysis revealed significant differences in theactA,inlF,inlG, andinlJallelic profiles between clinical isolates (complex A) and nonclinical isolates (complex C). The association of particular alleles ofactA,inlF, and newly described alleles ofinlJwith isolates from CNS infections (particularly rhombencephalitis) suggests that these virulence genes participate in neurovirulence ofL. monocytogenes. The overall absence ofinlGin clinical complex A and its presence in complex C isolates suggests that the InlG protein is more relevant for the survival ofL. monocytogenesin the environment.

scholarly journals Evidence for Phenotypic Plasticity among Multihost Campylobacter jejuni and C. coli Lineages, Obtained Using Ribosomal Multilocus Sequence Typing and Raman Spectroscopy

2012 ◽  
Vol 79 (3) ◽  
pp. 965-973 ◽  
Author(s):  
Daniel S. Read ◽  
Dan J. Woodcock ◽  
Norval J. C. Strachan ◽  
Kenneth J. Forbes ◽  
Frances M. Colles ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Campylobacter Jejuni ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
Phenotypic Characterization ◽  
Spectrometric Analysis ◽  
Content Type ◽  
Automatic Relevance Determination ◽  
Clonal Origin

ABSTRACTClosely related bacterial isolates can display divergent phenotypes. This can limit the usefulness of phylogenetic studies for understanding bacterial ecology and evolution. Here, we compare phenotyping based on Raman spectrometric analysis of cellular composition to phylogenetic classification by ribosomal multilocus sequence typing (rMLST) in 108 isolates of the zoonotic pathogensCampylobacter jejuniandC. coli. Automatic relevance determination (ARD) was used to identify informative peaks in the Raman spectra that could be used to distinguish strains in taxonomic and host source groups (species, clade, clonal complex, and isolate source/host). Phenotypic characterization based on Raman spectra showed a degree of agreement with genotypic classification using rMLST, with segregation accuracy between species (83.95%), clade (inC. coli, 98.41%), and, to some extent, clonal complex (86.89%C. jejuniST-21 and ST-45 complexes) being achieved. This confirmed the utility of Raman spectroscopy for lineage classification and the correlation between genotypic and phenotypic classification. In parallel analysis, relatively distantly related isolates (different clonal complexes) were assigned the correct host origin irrespective of the clonal origin (74.07 to 96.97% accuracy) based upon different Raman peaks. This suggests that the phenotypic characteristics, from which the phenotypic signal is derived, are not fixed by clonal descent but are influenced by the host environment and change as strains move between hosts.

scholarly journals Transport and Catabolism of Pentitols by Listeria monocytogenes

2016 ◽  
Vol 26 (6) ◽  
pp. 369-380 ◽  
Author(s):  
Takfarinas Kentache ◽  
Eliane Milohanic ◽  
Thanh Nguyen Cao ◽  
Abdelhamid Mokhtari ◽  
Francine Moussan Aké ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Pentose Phosphate ◽  
Phosphotransferase System ◽  
Virulence Gene Expression ◽  
Transposon Insertion ◽  
Encoding Gene ◽  
High Concentrations ◽  
Transcription Activators

Transposon insertion into <i>Listeria monocytogenes lmo2665</i>, which encodes an EIIC of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), was found to prevent <smlcap>D</smlcap>-arabitol utilization. We confirm this result with a deletion mutant and show that Lmo2665 is also required for <smlcap>D</smlcap>-xylitol utilization. We therefore called this protein EIIC<sup>Axl</sup>. Both pentitols are probably catabolized via the pentose phosphate pathway (PPP) because <i>lmo2665</i> belongs to an operon, which encodes the three PTS<sup>Axl</sup> components, two sugar-P dehydrogenases, and most PPP enzymes. The two dehydrogenases oxidize the pentitol-phosphates produced during PTS-catalyzed transport to the PPP intermediate xylulose-5-P. <i>L. monocytogenes</i> contains another PTS, which exhibits significant sequence identity to PTS<sup>Axl</sup>. Its genes are also part of an operon encoding PPP enzymes. Deletion of the EIIC-encoding gene <i>(lmo0508)</i> affected neither <smlcap>D</smlcap>-arabitol nor <smlcap>D</smlcap>-xylitol utilization, although <smlcap>D</smlcap>-arabitol induces the expression of this operon. Both operons are controlled by MtlR/LicR-type transcription activators (Lmo2668 and Lmo0501, respectively). Phosphorylation of Lmo0501 by the soluble PTS<sup>Axl</sup> components probably explains why <smlcap>D</smlcap>-arabitol also induces the second pentitol operon. Listerial virulence genes are submitted to strong repression by PTS sugars, such as glucose. However, <smlcap>D</smlcap>-arabitol inhibited virulence gene expression only at high concentrations, probably owing to its less efficient utilization compared to glucose.

Analysis of Additional Virulence Genes and Virulence Gene Regions in Listeria monocytogenes Confirms the Epidemiologic Relevance of Multi-Virulence-Locus Sequence Typing

2008 ◽  
Vol 71 (12) ◽  
pp. 2559-2566 ◽  
Author(s):  
SARA LOMONACO ◽  
YI CHEN ◽  
STEPHEN J. KNABEL
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Listeria Monocytogenes ◽  
Virulence Genes ◽  
Virulence Gene ◽  
The Other ◽  
Evolutionary Divergence ◽  
Gene Sequences ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Molecular Subtyping

Previous molecular subtyping studies have defined four epidemic clones (ECs) of Listeria monocytogenes (ECI, ECII, ECIII, and ECIV). Partial sequences of eight virulence genes were previously shown to be identical within individual ECs of L. monocytogenes. The present study was conducted to determine if the sequences of other virulence genes and virulence gene regions are also conserved within these ECs. Six additional virulence genes—bsh, hly, inlJ, lplA1, pgdA, and srtA—and three additional virulence gene regions of actA, inlA, and inlB were selected based on their role in L. monocytogenes virulence, and intragenic regions of each gene were sequenced. Sequencing was performed on a diverse set of 44 to 48 L. monocytogenes strains. Results demonstrated that the sequenced regions of the nine virulence genes were identical within each of the ECs, and 257 new single nucleotide polymorphism (SNPs) were identified. ECIII (lineage II) was easily distinguishable from the other ECs, as 238 SNPs were observed in ECIII due to its significant evolutionary divergence from lineage I. With regard to the other ECs, there were 5 SNPs that represented an informative set, since these SNPs were able to differentiate specific ECs from all other unrelated strains used in this study. This study confirms our previous finding that virulence gene sequences are highly conserved within individual ECs and contain stable SNPs that can be used to very accurately differentiate ECs of L. monocytogenes from each other and from other diverse strains.

Development of a Multilocus sequence typing (MLST) scheme for Pan-Leishmania

Acta Tropica ◽  
2020 ◽  
Vol 201 ◽  
pp. 105189
Author(s):  
Juan Jose Lauthier ◽  
Paula Ruybal ◽  
Paola Andrea Barroso ◽  
Yoshihisa Hashiguchi ◽  
Jorge Diego Marco ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Mlst Scheme
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