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Mikrobiyoloji Bulteni Jan 2020Enterococci, which are commonly found in the environment, cause serious infections despite the absence of well-defined virulence factors and toxins. Knowing the...
Enterococci, which are commonly found in the environment, cause serious infections despite the absence of well-defined virulence factors and toxins. Knowing the virulence properties of enterococci is important to understand the complex pathogenic structures. In this study, we aimed to investigate the virulence factors (asa1, hyl, cylA, efa, ebp, ace, esp, gelE, sprE, fsrA, fsrB, fsrC genes, gelatinase activity, hemolysin, hydrogen peroxide and biofilm production) and antibiotic resistance of Enterococcus faecium and Enterococcus faecalis strains isolated from clinical specimens. A total of 110 enterococcus isolates which were accepted as infectious agents were included in the study. The polymerase chain reaction method was used to identify the isolates and to detect virulence genes. Characteristics of hemolysis, biofilm formation, hydrogen peroxide production and gelatinase activity were investigated by phenotypic methods. The antibiotic susceptibility test was performed with VITEK 2 automated system. E.faecalis ATCC 29212 standard strain was used as a quality control in all tests. Of the 110 enterococci isolates included in the study, 61 were identified as E.faecium and 49 as E.faecalis. The efa gene was the most frequently detected virulence gene (92.7%), followed by ace (83.6%), esp (66.4%), ebp (60.0%), cylA (50.9%), hyl (46.4%), asa1 (45.5%), gelE, sprE, fsrC (33.6%), fsrA (12.7%) and fsrB (11.8%). All genes except hyl were higher in E.faecalis isolates and the difference was statistically significant (p<0.05). Twenty-five (51%) E.faecalis and 1 (1.6%) E.faecium isolates had beta-hemolysis and the difference was statistically significant (p= 0.000). Seven (11.5%) E.faecium and 4 (8.2%) E.faecalis isolates formed biofilm, but the difference was not statistically significant (p> 0.05). Two (3.3%) E.faecium and 14 (28.6%) E.faecalis isolates exhibited gelatinase activity and the difference between the two species was statistically significant (p= 0.000). Hydrogen peroxide production was not detected in any of the isolates. The highest resistance rate was determined against ciprofloxacin (70.9%). The resistance to ampicillin was 69.1%, high level streptomycin 65.1%, high level gentamicin 39.4%, vancomycin and teicoplanin 4.5%, and linezolid 1.8%. In conclusion, our data indicated that virulence factors except hyl gene and biofilm production were higher in E.faecalis isolates but E.faecium isolates were more resistant to antibiotics. In order to prevent infection of such virulent or resistant isolates in the hospital setting, infection control measures must be followed. In vivo studies are needed for the better understanding of the virulence of enterococci.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Virulence Factors
PubMed: 32050876
DOI: 10.5578/mb.68810 -
Frontiers in Cellular and Infection... 2023As a probiotic, enterococcus faecium (E. faecium) has the characteristics of high temperature resistance, gastric acid resistance, bile salt resistance, etc. It can also... (Review)
Review
As a probiotic, enterococcus faecium (E. faecium) has the characteristics of high temperature resistance, gastric acid resistance, bile salt resistance, etc. It can also effectively improve animal performance and immunity and improve the animal's intestinal environment, so in recent years it has been more widely used in the livestock industry. However, due to the improper use of antibiotics and the growing environmental stress of strains, the drug resistance of enterococcus faecium has become more and more serious, and because some enterococcus faecium carry virulence genes, leading to the emergence of pathogenic strains, its safety issues have been widely concerned. This paper focuses on the biological characteristics of enterococcus faecium, the application of this bacterium in animal husbandry and the safety issues in its use, with a view to providing a reference for the application of enterococcus faecium in the development of animal husbandry.
Topics: Animals; Enterococcus faecium; Animal Husbandry; Anti-Bacterial Agents; Bile Acids and Salts; Livestock
PubMed: 37600940
DOI: 10.3389/fcimb.2023.1168189 -
Microbiology Spectrum Feb 2022Considered a serious threat by the Centers for Disease Control and Prevention, multidrug-resistant Enterococcus faecium is an increasing cause of hospital-acquired...
Considered a serious threat by the Centers for Disease Control and Prevention, multidrug-resistant Enterococcus faecium is an increasing cause of hospital-acquired infection. Here, we provide details on a single-plasmid CRISPR-Cas12a system for generating clean deletions and insertions. Single manipulations were carried out in under 2 weeks, with successful deletions/insertions present in >80% of the clones tested. Using this method, we generated three individual clean deletion mutations in the , , and genes and inserted codon-optimized , enabling green fluorescent protein (GFP)-like fluorescence under the control of the trehalase operon. The use of recombination for plasmid construction kept costs to a minimum. Enterococcus faecium is increasingly associated with hard-to-treat antibiotic-resistant infections. The ability to generate clean genomic alterations is the first step in generating a complete mechanistic understanding of how E. faecium acquires pathogenic traits and causes disease. Here, we show that CRISPR-Cas12a can be used to quickly (under 2 weeks) and cheaply delete or insert genes into the E. faecium genome. This substantial improvement over current methods should speed up research on this important opportunistic pathogen.
Topics: Bacterial Proteins; CRISPR-Cas Systems; Enterococcus faecium; Gene Editing; Genome, Bacterial; Mutagenesis, Insertional; Plasmids; Sequence Deletion
PubMed: 35107356
DOI: 10.1128/spectrum.02427-21 -
Journal of Microbiology and... Sep 2015The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts...
The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.
Topics: Cluster Analysis; Complex Mixtures; Cucurbitaceae; DNA, Bacterial; DNA, Ribosomal; Enterococcus faecium; Gibberellins; Indoleacetic Acids; Molecular Sequence Data; Oryza; Phylogeny; Plant Development; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology
PubMed: 25907061
DOI: 10.4014/jmb.1502.02011 -
Microbiology Spectrum Dec 2022It was recently proposed that Enterococcus faecium colonizing the human gut (previous clade B) actually corresponds to Enterococcus lactis. Our goals were to develop a...
It was recently proposed that Enterococcus faecium colonizing the human gut (previous clade B) actually corresponds to Enterococcus lactis. Our goals were to develop a PCR assay to rapidly differentiate these species and to discuss the main phenotypic and genotypic differences from a clinical perspective. The pan-genome of 512 genomes of E. faecium and E. lactis strains was analyzed to assess diversity in genes between the two species. Sequences were aligned to find the best candidate gene for designing species-specific primers, and their accuracy was tested with a collection of 382 enterococci. E. lactis isolates from clinical origins were further characterized by whole-genome sequencing (Illumina). Pan-genome analysis resulted in 12 gene variants, with gene (rhomboid protease) being selected as the candidate for species differentiation. The nucleotide sequence of diverged by 90 to 92% between sets, which allowed species identification through PCR with 100% specificity and no cross-reactivity. E. lactis strains were greatly pan-susceptible and not host specific. Hospital E. lactis isolates were susceptible to clinically relevant antibiotics, lacked infection-associated virulence markers, and were associated with patients presenting risk factors for enhanced bacterial translocation. Here, we propose a PCR-based assay using for easy routine differentiation between E. faecium and E. lactis that could be implemented in different public health contexts. We further suggest that E. lactis, a dominant human gut species, can cross the gut barrier in severely ill, immunodeficient, and surgical patients. Knowing that bacterial translocation may be a sepsis promoter, the relevance of infections caused by E. lactis strains, even if they are pan-susceptible, should be explored. Enterococcus faecium is a WHO priority pathogen that causes severe and hard-to-treat human infections. It was recently proposed that E. faecium colonizing the human gut (previous clade B) actually corresponds to Enterococcus lactis; therefore, some of the human infections occurring globally are being misidentified. In this work, we developed a PCR-based rapid identification method for the differentiation of E. faecium and E. lactis and discussed the main phenotypic and genotypic differences of these species from a clinical perspective. We identified the gene as the best candidate, based on the phylogenomic analysis of 512 published pan-genomes, and validated the PCR assay with a comprehensive collection of 382 enterococci obtained from different sources. Further detailed analysis of clinical E. lactis strains showed that they are highly susceptible to antibiotics and lack the typical virulence markers of E. faecium but are able to cause severe human infections in immunosuppressed patients, possibly in part due to gut barrier translocation.
Topics: Humans; Anti-Bacterial Agents; Enterococcus faecium; Genome, Bacterial; Gram-Positive Bacterial Infections; Polymerase Chain Reaction; Enterococcus
PubMed: 36453910
DOI: 10.1128/spectrum.03268-22 -
Virulence Nov 2017Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause... (Review)
Review
Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems.
Topics: Animals; Anti-Bacterial Agents; Biofilms; Disease Models, Animal; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans
PubMed: 28102784
DOI: 10.1080/21505594.2017.1279766 -
Journal of Microbiology (Seoul, Korea) Mar 2014The enterococci are commensals of the gastrointestinal tract of many metazoans, from insects to humans. While they normally do not cause disease in the intestine, they... (Review)
Review
The enterococci are commensals of the gastrointestinal tract of many metazoans, from insects to humans. While they normally do not cause disease in the intestine, they can become pathogenic when they infect sites outside of the gut. Recently, the enterococci have become important nosocomial pathogens, with the majority of human enterococcal infections caused by two species, Enterococcus faecalis and Enterococcus faecium. Studies using invertebrate infection models have revealed insights into the biology of enterococcal infections, as well as general principles underlying host innate immune defense. This review highlights recent findings on Enterococcus infection biology from two invertebrate infection models, the greater wax moth Galleria mellonella and the free-living bacteriovorous nematode Caenorhabditis elegans.
Topics: Animals; Caenorhabditis elegans; Disease Models, Animal; Enterococcus faecalis; Enterococcus faecium; Host-Pathogen Interactions; Immunity, Innate; Lepidoptera
PubMed: 24585051
DOI: 10.1007/s12275-014-4011-6 -
Probiotics and Antimicrobial Proteins Sep 2020Enterococci are commensals of human and other animals' gastrointestinal tracts. Only making up a small part of the microbiota, they have not played a significant role in... (Review)
Review
Enterococci are commensals of human and other animals' gastrointestinal tracts. Only making up a small part of the microbiota, they have not played a significant role in research, until the 1980s. Although the exact year is variable according to different geographical areas, this was the decade when vancomycin-resistant enterococci (VRE) were discovered and since then their role as causative agents of human infections has increased. Enterococcus faecium is on the WHO's list of "bacteria for which new antibiotics are urgently needed," and with no new antibiotics in development, the situation is desperate. In this review, different aspects of VRE are outlined, including the mortality caused by VRE, antibiotic resistance profiles, animal-modeling efforts, and virulence. In addition, the limitations of current antibiotic treatments for VRE and prospective new treatments, such as bacteriocins, are reviewed.
Topics: Animals; Bacteriocins; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Vancomycin-Resistant Enterococci; Virulence
PubMed: 31758332
DOI: 10.1007/s12602-019-09618-6 -
Brazilian Journal of Microbiology :... Mar 2015This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of...
This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.
Topics: Bacterial Adhesion; Brazil; Cheese; Chemical Phenomena; Cholic Acids; Clostridium perfringens; Enterococcus faecium; Escherichia coli; Food Handling; Food Safety; Gastrointestinal Tract; Hydrophobic and Hydrophilic Interactions; Inactivation, Metabolic; Microbial Viability; Polymerase Chain Reaction; Virulence Factors
PubMed: 26221113
DOI: 10.1590/S1517-838246120131245 -
Journal of Clinical Laboratory Analysis Dec 2020The aim of this study was to provide information about the spread and characteristics of the vancomycin-resistant Enterococcus faecium isolates (VREfm) in Turkey.
BACKGROUND
The aim of this study was to provide information about the spread and characteristics of the vancomycin-resistant Enterococcus faecium isolates (VREfm) in Turkey.
METHODS
Seventy-one nonduplicate consecutive isolates of VREfm were obtained from various clinical specimens of inpatients treated at university or training hospitals in seven regions of Turkey. Further characteristics included antibiotic susceptibility testing, pulsed-field gel electrophoresis (PFGE) of SmaI-digested genomic DNA, and multilocus sequence typing (MLST) of selected isolates. The presence of vancomycin resistance and virulence genes (esp and hyl) was investigated by polymerase chain reaction (PCR).
RESULTS
All VREfm isolates had MICs to vancomycin of ≥32 mg/L and contained the vanA gene. The presence of esp gene was identified in 64 and hyl in eight VREfm isolates. All VREfm showed the multiresistance phenotype, including ampicillin (99%), penicillin (99%), imipenem (99%), ciprofloxacin (87%), moxifloxacin (87%), erythromycin (97%), streptomycin (86%), gentamicin (82%), tetracycline (70%), and teicoplanin (99%). All were susceptible to tigecycline while quinupristin-dalfopristin (97%) and linezolid (93%) were the most active other agents. Analysis of the PFGE profiles showed that 53 (74.6%) VREfm isolates shared a similar electrophoretic profile, designed as type 1, and were closely related (>85%). The sequence type was identified by MLST in 44 VRE isolates with unrelated or closely related PFGE patterns. MLST revealed that nosocomial spread of VREfm resulted from dissemination of lineage C1 E faecium clones. Sequence types ST78, ST203, and ST117 were the most frequently isolated. This is the first report of ST733 around the world.
CONCLUSIONS
Lineage C1 clones are disseminated among clinical VREfm isolates in seven different regions in Turkey. Regarding VREfm isolates, the worldwide epidemic strains are in circulation in Turkey.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Cross Infection; Cross-Sectional Studies; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecium; Female; Gram-Positive Bacterial Infections; Humans; Infant; Male; Middle Aged; Multilocus Sequence Typing; Turkey; Vancomycin-Resistant Enterococci; Virulence Factors; Young Adult
PubMed: 33025699
DOI: 10.1002/jcla.23541