scholarly journals Characterization of genetic diversity and population structure within Staphylococcus chromogenes by multilocus sequence typing

2020 ◽  
Author(s):  
Rebeca Huebner ◽  
Robert Mugabi ◽  
Gabriella Hetesy ◽  
Lawrence Fox ◽  
Sarne De Vliegher ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Bovine Mastitis ◽  
The United States ◽  
Genetic Lineage ◽  
Single Nucleotide Variants ◽  
Discrimination Power ◽  
Core Group ◽  
Intramammary Infections ◽  
Mlst Scheme ◽  
Nucleotide Sequence Level

AbstractStaphylococcus chromogenes is a common skin commensal in cattle and has been identified as a frequent cause of bovine mastitis and intramammary infections. To better understand the extent of strain diversity within this species and to facilitate study of strain variation as a factor in pathogenicity, we have developed a seven locus Multilocus Sequence Typing (MLST) scheme. The scheme was tested on 120 isolates collected from three geographic locations, Vermont and Washington State in the United States and Belgium. A total of 46 sequence types (STs) were identified with most of the STs being location specific. The utility of the typing scheme is indicated by a discrimination power of 95.6% for all isolates and greater than 90% for isolates from each of the three locations. Phylogenetic analysis placed 39 of the 46 STs into single core group consistent with a common genetic lineage; the STs in this group differ by less than 0.5% at the nucleotide sequence level. Most of the diversification in this lineage group can be attributed to mutation; recombination plays a limited role. This lineage group includes two clusters of single nucleotide variants in starburst configurations indicative of recent clonal expansion; nearly 50% of the isolates sampled in this study are in these two clusters. The remaining seven STs were set apart from the core group by having alleles with highly variable sequences at one or more loci. Recombination had a higher impact than mutation in the diversification of these outlier STs. Alleles with hypervariable sequences were detected at five of the seven loci used in the MLST scheme; the average sequence distances between the hypervariable alleles and the common core alleles ranged from 12 to 34 nucleotides. The extent of these sequence differences suggests the hypervariable alleles may be remnants of an ancestral genotype.

scholarly journals Characterization of genetic diversity and population structure within Staphylococcus chromogenes by multilocus sequence typing

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0243688
Author(s):  
Rebeca Huebner ◽  
Robert Mugabi ◽  
Gabriella Hetesy ◽  
Lawrence Fox ◽  
Sarne De Vliegher ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Multilocus Sequence Typing ◽  
Bovine Mastitis ◽  
The United States ◽  
Genetic Lineage ◽  
Single Nucleotide Variants ◽  
Discrimination Power ◽  
Core Group ◽  
Mlst Scheme

Staphylococcus chromogenes is a common skin commensal in cattle and has been identified as a frequent cause of bovine mastitis and intramammary infections. We have developed a seven locus Multilocus Sequence Typing (MLST) scheme for typing S. chromogenes. Sequence-based typing systems, such as MLST, have application in studies of genetic diversity, population structure, and epidemiology, including studies of strain variation as a factor in pathogenicity or host adaptation. The S. chromogenes scheme was tested on 120 isolates collected from three geographic locations, Vermont and Washington State in the United States and Belgium. A total of 46 sequence types (STs) were identified with most of the STs being location specific. The utility of the typing scheme is indicated by a discrimination power of 95.6% for all isolates and greater than 90% for isolates from each of the three locations. Phylogenetic analysis placed 39 of the 46 STs into single core group consistent with a common genetic lineage; the STs in this group differ by less than 0.5% at the nucleotide sequence level. Most of the diversification in this lineage group can be attributed to mutation; recombination plays a limited role. This lineage group includes two clusters of single nucleotide variants in starburst configurations indicative of recent clonal expansion; nearly 50% of the isolates sampled in this study are in these two clusters. The remaining seven STs were set apart from the core group by having alleles with highly variable sequences at one or more loci. Recombination had a higher impact than mutation in the diversification of these outlier STs. Alleles with hypervariable sequences were detected at five of the seven loci used in the MLST scheme; the average sequence distances between the hypervariable alleles and the common core alleles ranged from 12 to 34 nucleotides. The extent of these sequence differences suggests the hypervariable alleles may be remnants of an ancestral genotype.

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 Multilocus Sequence Typing Reveals Two Evolutionary Lineages of Acidovorax avenae subsp. citrulli

2009 ◽  
Vol 99 (8) ◽  
pp. 913-920 ◽  
Author(s):  
Jianjun Feng ◽  
Erin L. Schuenzel ◽  
Jianqiang Li ◽  
Norman W. Schaad
Keyword(s):  
United States ◽  
Multilocus Sequence Typing ◽  
The United States ◽  
Causal Agent ◽  
Reliable Identification ◽  
Bacterial Fruit Blotch ◽  
Mlst Scheme ◽  
Evolutionary Lineages ◽  
Considerable Damage

Acidovorax avenae subsp. citrulli, causal agent of bacterial fruit blotch, has caused considerable damage to the watermelon and melon industry in China and the United States. Understanding the emergence and spread of this pathogen is important for controlling the disease. To build a fingerprinting database for reliable identification and tracking of strains of A. avenae subsp. citrulli, a multilocus sequence typing (MLST) scheme was developed using seven conserved loci. The study included 8 original strains from the 1978 description of A. avenae subsp. citrulli, 51 from China, and 34 from worldwide collections. Two major clonal complexes (CCs), CC1 and CC2, were identified within A. avenae subsp. citrulli; 48 strains typed as CC1 and 45 as CC2. All eight original 1978 strains isolated from watermelon and melon grouped in CC1. CC2 strains were predominant in the worldwide collection and all but five were isolated from watermelon. In China, a major seed producer for melon and watermelon, the predominant strains were CC1 and were found nearly equally on melon and watermelon.

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 Carios kelleyi (Acari: Ixodida: Argasidae) Infected With Rickettsial Agents Documented Infesting Housing in Kansas, United States

2021 ◽  
Author(s):  
Robyn M Nadolny ◽  
Ashley C Kennedy ◽  
James M Rodgers ◽  
Zachary T Vincent ◽  
Hannah Cornman ◽  
...  
Keyword(s):  
Public Health ◽  
United States ◽  
Health Center ◽  
Human Disease ◽  
Multilocus Sequence Typing ◽  
The United States ◽  
Rickettsia Species ◽  
History Of ◽  
Tick Borne Disease ◽  
Blood Meals

Abstract During September–December 2018, 25 live ticks were collected on-post at Fort Leavenworth, Kansas, in a home with a history of bat occupancy. Nine ticks were sent to the Army Public Health Center Tick-Borne Disease Laboratory and were identified as Carios kelleyi (Cooley and Kohls, 1941), a species that seldom bites humans but that may search for other sources of blood meals, including humans, when bats are removed from human dwellings. The ticks were tested for numerous agents of human disease. Rickettsia lusitaniae was identified by multilocus sequence typing to be present in two ticks, marking the first detection of this Rickettsia agent in the United States and in this species of tick. Two other Rickettsia spp. were also detected, including an endosymbiont previously associated with C. kelleyi and a possible novel Rickettsia species. The potential roles of C. kelleyi and bats in peridomestic Rickettsia transmission cycles warrant further investigation.

scholarly journals Comparative Genetic Analysis of Magnaporthe oryzae Isolates Causing Gray Leaf Spot of Perennial Ryegrass Turf in the United States and Japan

Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Tosa ◽  
W. Uddin ◽  
G. Viji ◽  
S. Kang ◽  
S. Mayama
Keyword(s):  
United States ◽  
Perennial Ryegrass ◽  
Magnaporthe Oryzae ◽  
Leaf Spot ◽  
Genetic Relationships ◽  
The United States ◽  
Gray Leaf Spot ◽  
Genetic Lineage ◽  
Type I ◽  
Type Ii

Gray leaf spot caused by Magnaporthe oryzae is a serious disease of perennial ryegrass (Lolium perenne) turf in golf course fairways in the United States and Japan. Genetic relationships among M. oryzae isolates from perennial ryegrass (prg) isolates within and between the two countries were examined using the repetitive DNA elements MGR586, Pot2, and MAGGY as DNA fingerprinting probes. In all, 82 isolates of M. oryzae, including 57 prg isolates from the United States collected from 1995 to 2001, 1 annual ryegrass (Lolium multiflorum) isolate from the United States collected in 1972, and 24 prg isolates from Japan collected from 1996 to 1999 were analyzed in this study. Hybridization with the MGR586 probe resulted in approximately 30 DNA fragments in 75 isolates (designated major MGR586 group) and less than 15 fragments in the remaining 7 isolates (designated minor MGR586 group). Both groups were represented among the 24 isolates from Japan. All isolates from the United States, with the exception of one isolate from Maryland, belonged to the major MGR586 group. Some isolates from Japan exhibited MGR586 fingerprints that were identical to several isolates collected in Pennsylvania. Similarly, fingerprinting analysis with the Pot2 probe also indicated the presence of two distinct groups: isolates in the major MGR586 group showed fingerprinting profiles comprising 20 to 25 bands, whereas the isolates in the minor MGR586 group had less than 10 fragments. When MAGGY was used as a probe, two distinct fingerprint types, one exhibiting more than 30 hybridizing bands (type I) and the other with only 2 to 4 bands (type II), were identified. Although isolates of both types were present in the major MGR586 group, only the type II isolates were identified in the minor MGR586 group. The parsimony tree obtained from combined MGR586 and Pot2 data showed that 71 of the 82 isolates belonged to a single lineage, 5 isolates formed four different lineages, and the remaining 6 (from Japan) formed a separate lineage. This study indicates that the predominant groups of M. oryzae associated with the recent outbreaks of gray leaf spot in Japan and the United States belong to the same genetic lineage.

Childhood Lead Poisoning and Other People’s Children

2017 ◽  
Author(s):  
Linda C. Fentiman
Keyword(s):  
Lead Poisoning ◽  
Behavioral Problems ◽  
Urban Areas ◽  
The United States ◽  
Childhood Lead Poisoning ◽  
Core Group ◽  
Lead Paint ◽  
American Children ◽  
American Legal System ◽  
To Receive

This chapter examines childhood lead poisoning, which causes severe and irreversible cognitive and nervous system impairment, as well as behavioral problems, in more than half a million American children each year. While the United States has addressed some causes of lead poisoning, a core group of children, concentrated in poor, urban areas in the Northeast and Midwest, remains at high risk. In nearly every state, manufacturers of lead paint and other lead products have not been held responsible for this harm, even though they were aware of the risks of lead poisoning since the nineteenth century. Many landlords in lead poisoning cases succeed in shifting the blame from themselves to the tenants, arguing that mothers are the actual cause of harm to the child. Because the American legal system has traditionally preferred to find a single cause of harm that cuts off others’ responsibility, many children injured by exposure to lead fail to receive compensation and treatment for their injuries.

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.

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

scholarly journals Draft Genome Sequences of 27 Staphylococcus aureus Strains and 3 Staphylococcus Species Strains Isolated from Bovine Intramammary Infections

2020 ◽  
Vol 9 (19) ◽  
Author(s):  
Soyoun Park ◽  
Dongyun Jung ◽  
Simon Dufour ◽  
Jennifer Ronholm
Keyword(s):  
Staphylococcus Aureus ◽  
Draft Genome ◽  
Bovine Mastitis ◽  
Holstein Cows ◽  
Whole Genome ◽  
Genome Sequences ◽  
Content Type ◽  
Intramammary Infections ◽  
Intramammary Infection ◽  
Etiological Agents

Staphylococcus aureus is one of the most common etiological agents responsible for contagious bovine mastitis. Here, we report the draft whole-genome sequences, with annotations, of 27 S. aureus strains and 3 Staphylococcus species strains that were isolated from Holstein cows with intramammary infection in Canada.

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