scholarly journals Do Staphylococcus epidermidis Genetic Clusters Predict Isolation Sources?

2016 ◽  
Vol 54 (7) ◽  
pp. 1711-1719 ◽  
Author(s):  
Isaiah Tolo ◽  
Jonathan C. Thomas ◽  
Rebecca S. B. Fischer ◽  
Eric L. Brown ◽  
Barry M. Gray ◽  
...  
Keyword(s):  
Population Structure ◽  
Staphylococcus Epidermidis ◽  
Learning Algorithm ◽  
Mobile Element ◽  
Single Nucleotide ◽  
Content Type ◽  
Hospital Patients ◽  
Contaminant Sources ◽  
Genetic Clusters ◽  
Sequence Types

Staphylococcus epidermidisis a ubiquitous colonizer of human skin and a common cause of medical device-associated infections. The extent to which the population genetic structure ofS. epidermidisdistinguishes commensal from pathogenic isolates is unclear. Previously, Bayesian clustering of 437 multilocus sequence types (STs) in the international database revealed a population structure of six genetic clusters (GCs) that may reflect the species' ecology. Here, we first verified the presence of six GCs, including two (GC3 and GC5) with significant admixture, in an updated database of 578 STs. Next, a single nucleotide polymorphism (SNP) assay was developed that accurately assigned 545 (94%) of 578 STs to GCs. Finally, the hypothesis that GCs could distinguish isolation sources was tested by SNP typing and GC assignment of 154 isolates from hospital patients with bacteremia and those with blood culture contaminants and from nonhospital carriage. GC5 was isolated almost exclusively from hospital sources. GC1 and GC6 were isolated from all sources but were overrepresented in isolates from nonhospital and infection sources, respectively. GC2, GC3, and GC4 were relatively rare in this collection. No association was detected betweenfdh-positive isolates (GC2 and GC4) and nonhospital sources. Using a machine learning algorithm, GCs predicted hospital and nonhospital sources with 80% accuracy and predicted infection and contaminant sources with 45% accuracy, which was comparable to the results seen with a combination of five genetic markers (icaA, IS256,sesD[bhp],mecA, and arginine catabolic mobile element [ACME]). Thus, analysis of population structure with subgenomic data shows the distinction of hospital and nonhospital sources and the near-inseparability of sources within a hospital.

scholarly journals Comparative genomics of Staphylococcus epidermidis from prosthetic-joint infections and nares highlights genetic traits associated with antimicrobial resistance, not virulence

2021 ◽  
Author(s):  
Emeli Månsson ◽  
Thor Bech Johannesen ◽  
Åsa Nilsdotter-Augustinsson ◽  
Bo Söderquist ◽  
Marc Stegger
Keyword(s):  
Population Structure ◽  
Antimicrobial Resistance ◽  
Staphylococcus Epidermidis ◽  
Type Species ◽  
Genetic Traits ◽  
Content Type ◽  
Link Type ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections

There is increased awareness of the worldwide spread of specific epidemic multidrug-resistant (MDR) lineages of the human commensal Staphylococcus epidermidis . Here, using bioinformatic analyses accounting for population structure, we determined genomic traits (genes, SNPs and k-mers) that distinguish S. epidermidis causing prosthetic-joint infections (PJIs) from commensal isolates from nares, by analysing whole-genome sequencing data from S. epidermidis from PJIs prospectively collected over 10 years in Sweden, and contemporary S. epidermidis from the nares of patients scheduled for arthroplasty surgery. Previously suggested virulence determinants and the presence of genes and mutations linked to antimicrobial resistance (AMR) were also investigated. Publicly available S. epidermidis sequences were used for international extrapolation and validation of findings. Our data show that S. epidermidis causing PJIs differed from nasal isolates not by virulence but by traits associated with resistance to compounds used in prevention of PJIs: β-lactams, aminoglycosides and chlorhexidine. Almost a quarter of the PJI isolates did not belong to any of the previously described major nosocomial lineages, but the AMR-related traits were also over-represented in these isolates, as well as in international S. epidermidis isolates originating from PJIs. Genes previously associated with virulence in S. epidermidis were over-represented in individual lineages, but failed to reach statistical significance when adjusted for population structure. Our findings suggest that the current strategies for prevention of PJIs select for nosocomial MDR S. epidermidis lineages that have arisen from horizontal gene transfer of AMR-related traits into multiple genetic backgrounds.

scholarly journals Population Structure and Antimicrobial Resistance of Canine UropathogenicEscherichia coli

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Tessa E. LeCuyer ◽  
Barbara A. Byrne ◽  
Joshua B. Daniels ◽  
Dubraska V. Diaz-Campos ◽  
G. Kenitra Hammac ◽  
...  
Keyword(s):  
Population Structure ◽  
Antimicrobial Resistance ◽  
Companion Animals ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Extraintestinal Disease ◽  
Human Infections ◽  
Sequence Types

ABSTRACTEscherichia coliis the most common cause of human and canine urinary tract infection (UTI). Clonal groups, often with high levels of antimicrobial resistance, are a major component of theE. colipopulation that causes human UTI. While little is known about the population structure ofE. colithat causes UTI in dogs, there is evidence that dogs and humans can share fecal strains ofE. coliand that human-associated strains can cause disease in dogs. In order to better characterize theE. colistrains that cause canine UTI, we analyzed 295E. coliisolates obtained from canine urine samples from five veterinary diagnostic laboratories and analyzed their multilocus sequence types, phenotypic and genotypic antimicrobial resistance profiles, and virulence-associated gene repertoires. Sequence type 372 (ST372), an infrequent human pathogen, was the predominant sequence type in dogs at all locations. Extended-spectrum β-lactamase-producing isolates withblaCTX-Mgenes were uncommon in canine isolates but when present were often associated with sequence types that have been described in human infections. This provides support for occasional cross-host-species sharing of strains that cause extraintestinal disease and highlights the importance of understanding the role of companion animals in the overall transmission patterns of extraintestinal pathogenicE. coli.

scholarly journals Molecular Characterization of IMP-1-Producing Enterobacter cloacae Complex Isolates in Tokyo

2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Kotaro Aoki ◽  
Sohei Harada ◽  
Koji Yahara ◽  
Yoshikazu Ishii ◽  
Daisuke Motooka ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
Asia Pacific ◽  
Single Nucleotide ◽  
Content Type ◽  
Plasmid Analysis ◽  
Enterobacter Hormaechei ◽  
Clade 1 ◽  
Genetic Structures ◽  
Sequence Types

ABSTRACT Although KPC enzymes are most common among carbapenemases produced by Enterobacter cloacae complex globally, the epidemiology varies from one country to another. While previous studies have suggested that IMP enzymes are most common in Japan, detailed analysis has been scarce thus far. Here, we carried out a molecular epidemiological study and plasmid analysis of IMP-1-producing E. cloacae complex isolates collected from three hospitals in central Tokyo using whole-genome sequencing. Seventy-one isolates were classified into several sequence types (STs), and 49 isolates were identified as Enterobacter hormaechei ST78. Isolates of ST78 were divided into three clades by core-genome single nucleotide polymorphism (SNP)-based phylogenetic analysis. Whereas isolates of clade 3 were isolated from only one hospital, isolates of clade 1 and 2 were identified from multiple hospitals. Ten of 12 clade 1 isolates and 1 of 4 clade 2 isolates carried bla IMP-1 on IncHI2 plasmids, with high similarity of genetic structures. In addition, these plasmids shared backbone structures with IncHI2 plasmids carrying bla IMP reported from other countries of the Asia-Pacific region. All isolates of clade 3 except one carried bla IMP-1 in In1426 on IncW plasmids. An isolate of clade 3, which lacked IncW plasmids, carried bla IMP-1 in In1426 on an IncFIB plasmid. These observations suggest that IMP-producing E. cloacae complex isolates with a diversity of host genomic backgrounds have spread in central Tokyo, and they indicate the possible contribution of IncHI2 plasmids toward this phenomenon.

scholarly journals Restricted Gene Flow among Hospital Subpopulations of Enterococcus faecium

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Rob J. L. Willems ◽  
Janetta Top ◽  
Willem van Schaik ◽  
Helen Leavis ◽  
Marc Bonten ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Enterococcus Faecium ◽  
Population Genetic ◽  
Effective Control ◽  
Phylogenomic Analysis ◽  
Content Type ◽  
Sequence Types ◽  
Insight Into

ABSTRACT Enterococcus faecium has recently emerged as an important multiresistant nosocomial pathogen. Defining population structure in this species is required to provide insight into the existence, distribution, and dynamics of specific multiresistant or pathogenic lineages in particular environments, like the hospital. Here, we probe the population structure of E. faecium using Bayesian-based population genetic modeling implemented in Bayesian Analysis of Population Structure (BAPS) software. The analysis involved 1,720 isolates belonging to 519 sequence types (STs) (491 for E. faecium and 28 for Enterococcus faecalis). E. faecium isolates grouped into 13 BAPS (sub)groups, but the large majority (80%) of nosocomial isolates clustered in two subgroups (2-1 and 3-3). Phylogenetic and eBURST analysis of BAPS groups 2 and 3 confirmed the existence of three separate hospital lineages (17, 18, and 78), highlighting different evolutionary trajectories for BAPS 2-1 (lineage 78) and 3-3 (lineage 17 and lineage 18) isolates. Phylogenomic analysis of 29 E. faecium isolates showed agreement between BAPS assignment of STs and their relative positions in the phylogenetic tree. Odds ratio calculation confirmed the significant association between hospital isolates with BAPS 3-3 and lineages 17, 18, and 78. Admixture analysis showed a scarce number of recombination events between the different BAPS groups. For the E. faecium hospital population, we propose an evolutionary model in which strains with a high propensity to colonize and infect hospitalized patients arise through horizontal gene transfer. Once adapted to the distinct hospital niche, this subpopulation becomes isolated, and recombination with other populations declines. IMPORTANCE Multiresistant Enterococcus faecium has become one of the most important nosocomial pathogens, causing increasing numbers of nosocomial infections worldwide. Here, we used Bayesian population genetic analysis to identify groups of related E. faecium strains and show a significant association of hospital and farm animal isolates to different genetic groups. We also found that hospital isolates could be divided into three lineages originating from sequence types (STs) 17, 18, and 78. We propose that, driven by the selective pressure in hospitals, the three hospital lineages have arisen through horizontal gene transfer, but once adapted to the distinct pathogenic niche, this population has become isolated and recombination with other populations declines. Elucidation of the population structure is a prerequisite for effective control of multiresistant E. faecium since it provides insight into the processes that have led to the progressive change of E. faecium from an innocent commensal to a multiresistant hospital-adapted pathogen.

scholarly journals Evolutionary Origin of the Staphylococcal Cassette Chromosome mec (SCCmec)

2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Joana Rolo ◽  
Peder Worning ◽  
Jesper Boye Nielsen ◽  
Rory Bowden ◽  
Ons Bouchami ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Insertion Site ◽  
Mobile Element ◽  
Comparative Genomic ◽  
Snp Analysis ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Content Type ◽  
Staphylococcal Species ◽  
Staphylococcal Cassette Chromosome

ABSTRACT Several lines of evidence indicate that the most primitive staphylococcal species, those of the Staphylococcus sciuri group, were involved in the first stages of evolution of the staphylococcal cassette chromosome mec (SCCmec), the genetic element carrying the β-lactam resistance gene mecA. However, many steps are still missing from this evolutionary history. In particular, it is not known how mecA was incorporated into the mobile element SCC prior to dissemination among Staphylococcus aureus and other pathogenic staphylococcal species. To gain insights into the possible contribution of several species of the Staphylococcus sciuri group to the assembly of SCCmec, we sequenced the genomes of 106 isolates, comprising S. sciuri (n = 76), Staphylococcus vitulinus (n = 18), and Staphylococcus fleurettii (n = 12) from animal and human sources, and characterized the native location of mecA and the SCC insertion site by using a variety of comparative genomic approaches. Moreover, we performed a single nucleotide polymorphism (SNP) analysis of the genomes in order to understand SCCmec evolution in relation to phylogeny. We found that each of three species of the S. sciuri group contributed to the evolution of SCCmec: S. vitulinus and S. fleurettii contributed to the assembly of the mec complex, and S. sciuri most likely provided the mobile element in which mecA was later incorporated. We hypothesize that an ancestral SCCmec III cassette (an element carried by one of the most epidemic methicillin-resistant S. aureus clones) originated in S. sciuri possibly by a recombination event in a human host or a human-created environment and later was transferred to S. aureus.

scholarly journals Molecular Epidemiology of Staphylococcus epidermidis Clinical Isolates from U.S. Hospitals

2012 ◽  
Vol 56 (9) ◽  
pp. 4656-4661 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Lalitagauri M. Deshpande ◽  
Andrew J. Costello ◽  
David J. Farrell
Keyword(s):  
Staphylococcus Epidermidis ◽  
Resistance Mechanisms ◽  
23S Rrna ◽  
Content Type ◽  
Linezolid Resistance ◽  
Clonal Distribution ◽  
Resistant Strains ◽  
Resistance Rates ◽  
Susceptibility Profiles ◽  
Sequence Types

ABSTRACTThe epidemiology ofStaphylococcus epidermidisin U.S. hospitals remains limited. This study aimed to address the genetic backgrounds of linezolid-susceptible and -resistantS. epidermidisstrains (isolated in 2010), includingcfr-carrying strains. In addition, the antimicrobial susceptibility profiles and linezolid resistance mechanisms among clonal lineages were assessed. A total of 71S. epidermidisisolates were selected, and linezolid-resistant strains were screened forcfrand mutations in 23S rRNA, L3, and L4. All isolates were subjected to multilocus sequence typing (MLST), and the results were analyzed by eBURST. Overall, 27 sequence types (STs) were detected, and ST5 (21.1%) and ST2 (16.9%) predominated. The majority (62/71; 87.3%) of STs belonged to clonal complex 2 (CC2), which was mostly comprised of subclusters CC2-II (41/62; 66.1%) and CC2-I (21/62; 33.9%). Other STs were grouped within CC23 or CC32 or were singletons. CC2-I strains were more likely to display a methicillin (95.2% versus 33.3 to 70.7%), a linezolid (47.6% versus 0.0 to 7.3%), or a multidrug (81.0% versus 33.3 to 36.6%) resistance phenotype. Among linezolid-resistant isolates,cfrwas noted only within CC2 strains, and it was detected equally in the CC2-I (3/10; 30.0%) and CC2-II (1/3; 33.3%) subclusters. 23S rRNA mutations (G2576 [seven strains] and C2534 [one strain]) were observed only among CC2-I (8/10; 80.0%) isolates. Strains showing a G2576 alteration also had M156 (7/7; 100.0%) and/or H146 (6/7; 85.7%) L3 modifications. This study provides an overview of theS. epidermidisclonal distribution and reports higher resistance rates among CC2-I strains. The results show thatcfrmay be acquired and expressed by both CC2 main subclusters, while 23S rRNA mutations appeared more often within CC2-I strains. Interestingly, these 23S rRNA mutants also had L3 alterations, which may act synergistically or in a compensatory manner to minimize the fitness cost while providing survival advantages under selective pressure.

scholarly journals Population Structure of Salmonella enterica Serovar 4,[5],12:b:− Strains and Likely Sources of Human Infection

2013 ◽  
Vol 79 (17) ◽  
pp. 5121-5129 ◽  
Author(s):  
Anne Toboldt ◽  
Erhard Tietze ◽  
Reiner Helmuth ◽  
Ernst Junker ◽  
Angelika Fruth ◽  
...  
Keyword(s):  
Population Structure ◽  
Salmonella Enterica ◽  
Human Infection ◽  
Second Phase ◽  
Gene Repertoire ◽  
Fish Food ◽  
Content Type ◽  
Potential Sources ◽  
Human Infections ◽  
Sequence Types

ABSTRACTSalmonella entericaserovar 4,[5],12:b:− is a monophasic serovar not able to express the second-phase flagellar antigen (H2 antigen). In Germany, the serovar is occasionally isolated from poultry, reptiles, fish, food, and humans. In this study, a selection of 67 epidemiologically unrelatedSalmonella entericaserovar 4,[5],12:b:− strains isolated in Germany between 2000 and 2011 from the environment, animal, food, and humans was investigated by phenotypic and genotypic methods to better understand the population structure and to identify potential sources of human infections. Strains of this monophasic serovar were highly diverse. Within the 67 strains analyzed, we identified 52 different pulsed-field gel electrophoresis XbaI profiles, 12 different multilocus sequence types (STs), and 18 different pathogenicity array types. The relatedness of strains based on the pathogenicity gene repertoire (102 markers tested) was in good agreement with grouping by MLST.S. entericaserovar 4,[5],12:b:− is distributed across multiple unrelated eBurst groups and consequently is highly polyphyletic. Two sequence types (ST88 and ST127) were linked toS. entericaserovar Paratyphi B (d-tartrate positive), two single-locus variants of ST1583 were linked toS. entericaserovar Abony, and one sequence type (ST1484) was associated withS. entericaserovar Mygdal, a recently defined, new serovar. From the characterization of clinical isolates and those of nonhuman origin, it can be concluded that the potential sources of sporadic human infections withS. entericaserovar 4,[5],12:b:− most likely are mushrooms, shellfish/fish, and poultry.

scholarly journals Characterization of a Novel Arginine Catabolic Mobile Element (ACME) and Staphylococcal Chromosomal CassettemecComposite Island with Significant Homology to Staphylococcus epidermidis ACME Type II in Methicillin-Resistant Staphylococcus aureus Genotype ST22-MRSA-IV

2011 ◽  
Vol 55 (5) ◽  
pp. 1896-1905 ◽  
Author(s):  
Anna C. Shore ◽  
Angela S. Rossney ◽  
Orla M. Brennan ◽  
Peter M. Kinnevey ◽  
Hilary Humphreys ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Mobile Element ◽  
Type I ◽  
Type Ii ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Content Type ◽  
Arginine Catabolic Mobile Element

ABSTRACTThe arginine catabolic mobile element (ACME) is prevalent among methicillin-resistantStaphylococcus aureus(MRSA) isolates of sequence type 8 (ST8) and staphylococcal chromosomal cassettemec(SCCmec) type IVa (USA300) (ST8-MRSA-IVa isolates), and evidence suggests that ACME enhances the ability of ST8-MRSA-IVa to grow and survive on its host. ACME has been identified in a small number of isolates belonging to other MRSA clones but is widespread among coagulase-negative staphylococci (CoNS). This study reports the first description of ACME in two distinct strains of the pandemic ST22-MRSA-IV clone. A total of 238 MRSA isolates recovered in Ireland between 1971 and 2008 were investigated for ACME using a DNA microarray. Twenty-three isolates (9.7%) were ACME positive, and all were either MRSA genotype ST8-MRSA-IVa (7/23, 30%) or MRSA genotype ST22-MRSA-IV (16/23, 70%). Whole-genome sequencing and comprehensive molecular characterization revealed the presence of a novel 46-kb ACME and staphylococcal chromosomal cassettemec(SCCmec) composite island (ACME/SCCmec-CI) in ST22-MRSA-IVh isolates (n= 15). This ACME/SCCmec-CI consists of a 12-kb DNA region previously identified in ACME type II inS. epidermidisATCC 12228, a truncated copy of the J1 region of SCCmectype I, and a complete SCCmectype IVh element. The composite island has a novel genetic organization, with ACME located withinorfXand SCCmeclocated downstream of ACME. One PVL locus-positive ST22-MRSA-IVa isolate carried ACME located downstream of SCCmectype IVa, as previously described in ST8-MRSA-IVa. These results suggest that ACME has been acquired by ST22-MRSA-IV on two independent occasions. At least one of these instances may have involved horizontal transfer and recombination events between MRSA and CoNS. The presence of ACME may enhance dissemination of ST22-MRSA-IV, an already successful MRSA clone.

scholarly journals Epidemic Territorial Spread of IncP-2-Type VIM-2 Carbapenemase-Encoding Megaplasmids in Nosocomial Pseudomonas aeruginosa Populations

2021 ◽  
Vol 65 (4) ◽  
Author(s):  
Paweł Urbanowicz ◽  
Ibrahim Bitar ◽  
Radosław Izdebski ◽  
Anna Baraniak ◽  
Elżbieta Literacka ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Large Scale ◽  
High Efficiency ◽  
Donor Cell ◽  
Stress Factors ◽  
Single Nucleotide ◽  
S1 Nuclease ◽  
Content Type ◽  
Short Read Sequence ◽  
Sequence Types

ABSTRACT In 2003 to 2004, the first five VIM-2 metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa (MPPA) isolates with an In4-like integron, In461 (aadB-blaVIM-2-aadA6), on conjugative plasmids were identified in three hospitals in Poland. In 2005 to 2015, MPPA expanded much in the country, and as many as 80 isolates in a collection of 454 MPPA (∼18%) had In461, one of the two most common MBL-encoding integrons. The organisms occurred in 49 hospitals in 33 cities of 11/16 main administrative regions. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) classified them into 55 pulsotypes and 35 sequence types (STs), respectively, revealing their remarkable genetic diversity overall, with only a few small clonal clusters. S1 nuclease/hybridization assays and mating of 63 representative isolates showed that ∼85% of these had large In461-carrying plasmids, ∼350 to 550 kb, usually self-transmitting with high efficiency (∼10−1 to 10−2 per donor cell). The plasmids from 19 isolates were sequenced and subjected to structural and single-nucleotide-polymorphism (SNP)-based phylogenetic analysis. These formed a subgroup within a family of IncP-2-type megaplasmids, observed worldwide in pseudomonads from various environments and conferring resistance/tolerance to multiple stress factors, including antibiotics. Their microdiversity in Poland arose mainly from acquisition of different accessory fragments, as well as new resistance genes and multiplication of these. Short-read sequence and/or PCR mapping confirmed the In461-carrying plasmids in the remaining isolates to be the IncP-2 types. The study demonstrated a large-scale epidemic spread of multidrug resistance plasmids in P. aeruginosa populations, creating an epidemiological threat. It contributes to the knowledge on IncP-2 types, which are interesting research objects in resistance epidemiology, environmental microbiology, and biotechnology.

scholarly journals The Carbapenemase-Producing Klebsiella pneumoniae Population Is Distinct and More Clonal than the Carbapenem-Susceptible Population

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Andrés Esteban-Cantos ◽  
Belén Aracil ◽  
Verónica Bautista ◽  
Adriana Ortega ◽  
Noelia Lara ◽  
...  
Keyword(s):  
Population Structure ◽  
Klebsiella Pneumoniae ◽  
Population Parameters ◽  
Wild Type ◽  
Susceptible Population ◽  
Content Type ◽  
Resistant Population ◽  
Sequence Types ◽  
Type Strains ◽  
Susceptible Group

ABSTRACT We studied in parallel the population structure of 90 carbapenemase-producing and 88 carbapenemase-susceptible Klebsiella pneumoniae isolates collected in 20 Spanish hospitals, in the context of the EuSCAPE project. Fourteen and 50 multilocus sequence types (MLSTs) were detected among the carbapenemase-producing and carbapenem-susceptible isolates, respectively. ST11 and ST15 clones were more frequent in the carbapenemase-producing group than in the carbapenemase-susceptible group (P < 0.0001). Among the members of the carbapenem-suceptible group, the cefotaxime-resistant population showed population parameters that differed between the populations of the wild-type strains and the carbapenemase producers.

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