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1.
PLoS One ; 15(8): e0237011, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745091

RESUMO

Enterococcus faecalis infective endocarditis (EFIE) is a severe disease of increasing incidence. The objective was to analyze whether the outcome of patients with native valve EFIE (NVEFIE) treated with a short course of ampicillin plus ceftriaxone (4wAC) was similar to patients treated according to international guidelines (6wAC). Between January 2008 and June 2018, 1,978 consecutive patients with definite native valve IE were prospectively included in a national registry. Outcomes of patients with NVEFIE treated with 4wAC were compared to those of patients who received 6wAC. Three hundred and twenty-two patients (16.3%) had NVEFIE. One hundred and eighty-three (56.8%) received AC. Thirty-nine patients (21.3%) were treated with 4wAC for four weeks and 70 patients (38.3%) with 6wAC. There were no differences in age or comorbidity. Patients treated 6wAC presented a longer duration of symptoms before diagnosis (21 days, IQR 7-60 days vs. 7 days, IQR 1-22 days; p = 0.002). Six patients presented perivalvular abscess and all of these received 6wAC. Surgery was performed on 14 patients (35.9%) 4wAC and 34 patients (48.6%) 6wAC (p = 0.201). In-hospital mortality, one-year mortality and relapses among 4wAC and 6wAC patients were 10.3% vs. 11.4% (p = 0.851); 17.9% vs. 21.4% (p = 0.682) and 5.1% vs. 4.3% (p = 0.833), respectively. In conclusion, a four-week course of AC may be considered as an alternative regimen in NVEFIE, notably in patients with shorter duration of symptoms and those without perivalvular abscess. These results support the performance of a randomized clinical trial to evaluate the efficacy of this short regimen.


Assuntos
Ampicilina/uso terapêutico , Ceftriaxona/uso terapêutico , Endocardite Bacteriana/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Estudos de Coortes , Quimioterapia Combinada , Endocardite/tratamento farmacológico , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/patogenicidade , Feminino , Gentamicinas/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Masculino , Estudos Prospectivos , Fatores de Tempo
2.
Sci Rep ; 10(1): 3937, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127598

RESUMO

For a One-Health investigation of antimicrobial resistance (AMR) in Enterococcus spp., isolates from humans and beef cattle along with abattoirs, manured fields, natural streams, and wastewater from both urban and cattle feedlot sources were collected over two years. Species identification of Enterococcus revealed distinct associations across the continuum. Of the 8430 isolates collected, Enterococcus faecium and Enterococcus faecalis were the main species in urban wastewater (90%) and clinical human isolates (99%); Enterococcus hirae predominated in cattle (92%) and feedlot catch-basins (60%), whereas natural streams harbored environmental Enterococcus spp. Whole-genome sequencing of E. faecalis (n = 366 isolates) and E. faecium (n = 342 isolates), revealed source clustering of isolates, indicative of distinct adaptation to their respective environments. Phenotypic resistance to tetracyclines and macrolides encoded by tet(M) and erm(B) respectively, was prevalent among Enterococcus spp. regardless of source. For E. faecium from cattle, resistance to ß-lactams and quinolones was observed among 3% and 8% of isolates respectively, compared to 76% and 70% of human clinical isolates. Clinical vancomycin-resistant E. faecium exhibited high rates of multi-drug resistance, with resistance to all ß-lactam, macrolides, and quinolones tested. Differences in the AMR profiles among isolates reflected antimicrobial use practices in each sector of the One-Health continuum.


Assuntos
Antibacterianos/farmacologia , Enterococcus/patogenicidade , Farmacorresistência Bacteriana/genética , Enterococcus/efeitos dos fármacos , Enterococcus/genética , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/genética , Enterococcus faecium/patogenicidade , Humanos , Macrolídeos/farmacologia , Filogenia , Quinolonas/farmacologia , Tetraciclinas/farmacologia , Virulência , Sequenciamento Completo do Genoma , Resistência beta-Lactâmica/genética
3.
Mikrobiyol Bul ; 54(1): 26-39, 2020 Jan.
Artigo em Turco | MEDLINE | ID: mdl-32050876

RESUMO

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.


Assuntos
Enterococcus faecalis , Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Fatores de Virulência , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/genética , Enterococcus faecium/patogenicidade , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Fatores de Virulência/genética
4.
Am J Physiol Gastrointest Liver Physiol ; 318(1): G1-G9, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31604031

RESUMO

Perforations, anastomotic leak, and subsequent intra-abdominal sepsis are among the most common and feared complications of invasive interventions in the colon and remaining intestinal tract. During physiological healing, tissue protease activity is finely orchestrated to maintain the strength and integrity of the submucosa collagen layer in the wound. We (Shogan, BD et al. Sci Trans Med 7: 286ra68, 2015.) have previously demonstrated in both mice and humans that the commensal microbe Enterococcus faecalis selectively colonizes wounded colonic tissues and disrupts the healing process by amplifying collagenolytic matrix-metalloprotease activity toward excessive degradation. Here, we demonstrate for the first time, to our knowledge, a novel collagenolytic virulence mechanism by which E. faecalis is able to bind and locally activate the human fibrinolytic protease plasminogen (PLG), a protein present in high concentrations in healing colonic tissue. E. faecalis-mediated PLG activation leads to supraphysiological collagen degradation; in this study, we demonstrate this concept both in vitro and in vivo. This pathoadaptive response can be mitigated with the PLG inhibitor tranexamic acid (TXA) in a fashion that prevents clinically significant complications in validated murine models of both E. faecalis- and Pseudomonas aeruginosa-mediated colonic perforation. TXA has a proven clinical safety record and is Food and Drug Administration approved for topical application in invasive procedures, albeit for the prevention of bleeding rather than infection. As such, the novel pharmacological effect described in this study may be translatable to clinical trials for the prevention of infectious complications in colonic healing.NEW & NOTEWORTHY This paper presents a novel mechanism for virulence in a commensal gut microbe that exploits the human fibrinolytic system and its principle protease, plasminogen. This mechanism is targetable by safe and effective nonantibiotic small molecules for the prevention of infectious complications in the healing gut.


Assuntos
Colágeno Tipo IV/metabolismo , Colágeno Tipo I/metabolismo , Colo/microbiologia , Enterococcus faecalis/metabolismo , Fibrinólise , Infecções por Bactérias Gram-Positivas/microbiologia , Plasminogênio/metabolismo , Infecção da Ferida Cirúrgica/microbiologia , Cicatrização , Animais , Antibacterianos/farmacologia , Antifibrinolíticos/farmacologia , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Modelos Animais de Doenças , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/patogenicidade , Fibrinólise/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/metabolismo , Infecções por Bactérias Gram-Positivas/patologia , Infecções por Bactérias Gram-Positivas/prevenção & controle , Interações Hospedeiro-Patógeno , Humanos , Camundongos Endogâmicos C57BL , Plasminogênio/antagonistas & inibidores , Proteólise , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/prevenção & controle , Infecção da Ferida Cirúrgica/metabolismo , Infecção da Ferida Cirúrgica/patologia , Infecção da Ferida Cirúrgica/prevenção & controle , Ácido Tranexâmico/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Virulência , Cicatrização/efeitos dos fármacos
5.
Arch Microbiol ; 202(4): 765-772, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31822952

RESUMO

This research was conducted using 50 samples of popular traditional cheeses and 160 enterococcal clinical isolates. Phenotypic and genotypic methods used for identification of enterococci. Then, the incidences of antibacterial resistance and virulence traits were investigated. In total, 165 E. faecalis and 43 E. faecium obtained from traditional cheeses and different clinical isolates were analyzed in the study. Antibiotic susceptibility testing revealed 175(84.1%) isolates with multi-drug resistance (MDR) patterns, which was more common among clinical sources. The predominant virulence profile, including gelE, asa1 and cpd was detected within 47 (22.6%) of the MDR isolates. Our results showed that traditional cheeses and clinical E. faecalis isolates have distinct patterns of virulence traits. The identified enterococci with antibiotic resistance and associated virulence factors, could provide a potential risk to the public health.


Assuntos
Queijo/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/patogenicidade , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/patogenicidade , Infecções por Bactérias Gram-Positivas/microbiologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Enterococcus faecalis/genética , Enterococcus faecalis/isolamento & purificação , Enterococcus faecium/genética , Enterococcus faecium/isolamento & purificação , Genótipo , Humanos , Irã (Geográfico) , Testes de Sensibilidade Microbiana , Fenótipo , Fatores de Virulência/genética
6.
PLoS One ; 14(11): e0216762, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31675374

RESUMO

Enterococcus faecalis is a ubiquitous intestinal symbiont and common early colonizer of the neonatal gut. Although colonization with E. faecalis has been previously associated with decreased pathology of necrotizing enterocolitis (NEC), these bacteria have been also implicated as opportunistic pathogens. Here we characterized 21 strains of E. faecalis, naturally occurring in 4-day-old rats, for potentially pathogenic properties and ability to colonize the neonatal gut. The strains differed in hemolysis, gelatin liquefaction, antibiotic resistance, biofilm formation, and ability to activate the pro-inflammatory transcription factor NF-κB in cultured enterocytes. Only 3 strains, BB70, 224, and BB24 appreciably colonized the neonatal intestine on day 4 after artificial introduction with the first feeding. The best colonizer, strain BB70, effectively displaced E. faecalis of maternal origin. Whereas BB70 and BB24 significantly increased NEC pathology, strain 224 significantly protected from NEC. Our results show that different strains of E. faecalis may be pathogenic or protective in experimental NEC.


Assuntos
Enterococcus faecalis/patogenicidade , Enterocolite Necrosante/microbiologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Enterococcus faecalis/classificação , Enterococcus faecalis/genética , Enterocolite Necrosante/patologia , Enterocolite Necrosante/prevenção & controle , Enterócitos/microbiologia , Enterócitos/patologia , Feminino , Variação Genética , Humanos , Recém-Nascido , Intestinos/microbiologia , Intestinos/patologia , Fenótipo , Gravidez , Probióticos/uso terapêutico , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Virulência
8.
Genome Biol ; 20(1): 252, 2019 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-31767028

RESUMO

BACKGROUND: Recent metagenomic analyses have revealed dysbiosis of the gut microbiota of ulcerative colitis (UC) patients. However, the impacts of this dysbiosis are not fully understood, particularly at the strain level. RESULTS: We perform whole-genome shotgun sequencing of fecal DNA extracts from 13 healthy donors and 16 UC and 8 Crohn's disease (CD) patients. The microbiota of UC and CD patients is taxonomically and functionally divergent from that of healthy donors, with E. faecium being the most differentially abundant species between the two microbial communities. Transplantation of feces from UC or CD patients into Il10-/- mice promotes pathological inflammation and cytokine expression in the mouse colon, although distinct cytokine expression profiles are observed between UC and CD. Unlike isolates derived from healthy donors, E. faecium isolates from the feces of UC patients, along with E. faecium strain ATCC 19434, promotes colitis and colonic cytokine expression. Inflammatory E. faecium strains, including ATCC 19434 and a UC-derived strain, cluster separately from commercially available probiotic strains based on whole-genome shotgun sequencing analysis. The presence of E. faecium in fecal samples is associated with large disease extent and the need for multiple medications in UC patients. CONCLUSIONS: E. faecium strains derived from UC patients display an inflammatory genotype that causes colitis.


Assuntos
Colite Ulcerativa/microbiologia , Enterococcus faecalis/patogenicidade , Microbioma Gastrointestinal , Metagenoma , Animais , Estudos de Casos e Controles , Colite/etiologia , Colite/patologia , Colite Ulcerativa/tratamento farmacológico , Colo/patologia , Doença de Crohn/microbiologia , Modelos Animais de Doenças , Quimioterapia Combinada , Enterococcus faecalis/genética , Transplante de Microbiota Fecal , Fezes/microbiologia , Feminino , Humanos , Interleucina-10/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL
9.
Nature ; 575(7783): 505-511, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31723265

RESUMO

Chronic liver disease due to alcohol-use disorder contributes markedly to the global burden of disease and mortality1-3. Alcoholic hepatitis is a severe and life-threatening form of alcohol-associated liver disease. The gut microbiota promotes ethanol-induced liver disease in mice4, but little is known about the microbial factors that are responsible for this process. Here we identify cytolysin-a two-subunit exotoxin that is secreted by Enterococcus faecalis5,6-as a cause of hepatocyte death and liver injury. Compared with non-alcoholic individuals or patients with alcohol-use disorder, patients with alcoholic hepatitis have increased faecal numbers of E. faecalis. The presence of cytolysin-positive (cytolytic) E. faecalis correlated with the severity of liver disease and with mortality in patients with alcoholic hepatitis. Using humanized mice that were colonized with bacteria from the faeces of patients with alcoholic hepatitis, we investigated the therapeutic effects of bacteriophages that target cytolytic E. faecalis. We found that these bacteriophages decrease cytolysin in the liver and abolish ethanol-induced liver disease in humanized mice. Our findings link cytolytic E. faecalis with more severe clinical outcomes and increased mortality in patients with alcoholic hepatitis. We show that bacteriophages can specifically target cytolytic E. faecalis, which provides a method for precisely editing the intestinal microbiota. A clinical trial with a larger cohort is required to validate the relevance of our findings in humans, and to test whether this therapeutic approach is effective for patients with alcoholic hepatitis.


Assuntos
Bacteriófagos/fisiologia , Enterococcus faecalis/patogenicidade , Enterococcus faecalis/virologia , Microbioma Gastrointestinal , Hepatite Alcoólica/microbiologia , Hepatite Alcoólica/terapia , Terapia por Fagos , Alcoolismo/complicações , Alcoolismo/microbiologia , Animais , Enterococcus faecalis/isolamento & purificação , Etanol/efeitos adversos , Fígado Gorduroso/complicações , Fígado Gorduroso/microbiologia , Fezes/microbiologia , Feminino , Vida Livre de Germes , Hepatite Alcoólica/complicações , Hepatite Alcoólica/mortalidade , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Perforina/metabolismo
10.
mSphere ; 4(4)2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31341072

RESUMO

In Firmicutes, the nutrient-sensing regulators (p)ppGpp, the effector molecule of the stringent response, and CodY work in tandem to maintain bacterial fitness during infection. Here, we tested (p)ppGpp and codY mutant strains of Enterococcus faecalis in a catheter-associated urinary tract infection (CAUTI) mouse model and used global transcriptional analysis to investigate the relationship of (p)ppGpp and CodY. The absence of (p)ppGpp or single inactivation of codY led to lower bacterial loads in catheterized bladders and diminished biofilm formation on fibrinogen-coated surfaces under in vitro and in vivo conditions. Single inactivation of the bifunctional (p)ppGpp synthetase/hydrolase rel did not affect virulence, supporting previous evidence that the association of (p)ppGpp with enterococcal virulence is not dependent on the activation of the stringent response. Inactivation of codY in the (p)ppGpp0 strain restored E. faecalis virulence in the CAUTI model as well as the ability to form biofilms in vitro Transcriptome analysis revealed that inactivation of codY restores, for the most part, the dysregulated metabolism of (p)ppGpp0 cells. While a clear linkage between (p)ppGpp and CodY with expression of virulence factors could not be established, targeted transcriptional analysis indicates that a possible association between (p)ppGpp and c-di-AMP signaling pathways in response to the conditions found in the bladder may play a role in enterococcal CAUTI. Collectively, data from this study identify the (p)ppGpp-CodY network as an important contributor to enterococcal virulence in catheterized mouse bladder and support that basal (p)ppGpp pools and CodY promote virulence through maintenance of a balanced metabolism under adverse conditions.IMPORTANCE Catheter-associated urinary tract infections (CAUTIs) are one of the most frequent types of infection found in the hospital setting that can develop into serious and potentially fatal bloodstream infections. One of the infectious agents that frequently causes complicated CAUTI is the bacterium Enterococcus faecalis, a leading cause of hospital-acquired infections that are often difficult to treat due to the exceptional multidrug resistance of some isolates. Understanding the mechanisms by which E. faecalis causes CAUTI will aid in the discovery of new druggable targets to treat these infections. In this study, we report the importance of two nutrient-sensing bacterial regulators, named (p)ppGpp and CodY, for the ability of E. faecalis to infect the catheterized bladder of mice.


Assuntos
Proteínas de Bactérias/genética , Infecções Relacionadas a Cateter/microbiologia , Enterococcus faecalis/patogenicidade , Regulação Bacteriana da Expressão Gênica , Guanosina Pentafosfato/genética , Fatores de Transcrição/genética , Animais , Proteínas de Bactérias/metabolismo , Biofilmes , Infecções Relacionadas a Cateter/urina , Modelos Animais de Doenças , Enterococcus faecalis/genética , Feminino , Perfilação da Expressão Gênica , Guanosina Pentafosfato/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição/metabolismo , Infecções Urinárias/microbiologia , Virulência , Fatores de Virulência
11.
mSphere ; 4(4)2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292230

RESUMO

Commensal and generally harmless in healthy individuals, Enterococcus faecalis causes opportunistic infections in immunocompromised patients. Plasmid-cured E. faecalis strain VE14089, derived from sequenced reference strain V583, is widely used for functional studies due to its improved genetic amenability. Although strain VE14089 has no major DNA rearrangements, with the exception of an ∼20-kb integrated region of pTEF1 plasmid, the strain presented significant growth differences from the V583 reference strain of our collection (renamed VE14002). In the present study, genome sequencing of strain VE14089 identified additional point mutations. Excision of the integrated pTEF1 plasmid region and sequential restoration of wild-type alleles showing nonsilent mutations were performed to obtain the VE18379 reference-derivative strain. Recovery of the growth ability of the restored VE18379 strain at a level similar to that seen with the reference strain points to GreA and Spx as bacterial fitness determinants. Virulence potential in Galleria mellonella and intestinal colonization in mouse demonstrated host adaptation of the VE18379 strain equivalent to VE14002 host adaptation. We further demonstrated that deletion of the 16.8-kb variable region of the epa locus recapitulates the key role of Epa decoration in host adaptation, providing a genetic system to study the role of specific epa-variable regions in host adaptation independently of other genetic variations.IMPORTANCE E. faecalis strain VE14089 was derived from V583 cured of its plasmids. Although VE14089 had no major DNA rearrangements, it presented significant growth and host adaptation differences from the reference strain V583 of our collection. To construct a strain with better fitness, we sequenced the genome of VE14089, identified single nucleotide polymorphisms (SNPs), and repaired the genes that could account for these changes. Using this reference-derivative strain, we provide a novel genetic system to understand the role of the variable region of epa in the enterococcal lifestyle.


Assuntos
Proteínas de Bactérias/genética , Enterococcus faecalis/genética , Aptidão Genética , Polissacarídeos Bacterianos/genética , Animais , Enterococcus faecalis/patogenicidade , Genoma Bacteriano , Larva/microbiologia , Camundongos , Mariposas/microbiologia , Fenótipo , Mutação Puntual , Polimorfismo de Nucleotídeo Único , Virulência , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
12.
BMC Microbiol ; 19(1): 162, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299904

RESUMO

BACKGROUND: Linezolid-resistant enterococci pose great challenges in clinical practice. The aim of this study is to study the mechanisms underlying the resistance and genetic environment of antimicrobial resistance gene of linezolid-resistant enterococci. RESULTS: The linezolid MICs of 16 enterococci were 4 mg/L to 16 mg/L. Four strains belonged to multi-drug resistant (MDR) bacteria. The sequence types (STs) of 13 enterococci strains performed WGS were diverse: 3 ST476, 1 ST86, ST116, ST480, ST59, ST416, ST21, ST67, ST16, ST585 and ST18. None of them carried multi-drug resistance gene cfr. Only one strain had the G2658 T mutation of target 23S rRNA gene. Thirteen (13/16, 81.3%) strains harbored the novel oxazolidinone resistance gene optrA. WGS analysis showed that the optrA gene was flanked by sequence IS1216E insertion in 13 strains, and optrA was adjacent to transposons Tn558 in two strains and Tn554 in one strain. The optrA gene was identified to be co-localized with fexA, the resistance genes mediated florfenicol resistance in 13 strains, and ermA1, the resistance genes mediated erythromycin resistance in 9 strains, indicating that linezolid-resistant strains may be selected due to non-oxazolidinone antibiotics (i.e. macrolides and florfenicol) usage. CONCLUSION: Our findings demonstrate the high diversity of optrA-carrying genetic platforms. The mobile genetic elements (MGEs) may play an important role in the dissemination of optrA into the enterococci isolates of human origin. The genetic evidence of transferable feature and co-selection of optrA should be gave more attention in clinical practice.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Enterococcus faecalis , Enterococcus faecium , Infecções por Bactérias Gram-Positivas/microbiologia , China , DNA Bacteriano , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Enterococcus faecium/genética , Enterococcus faecium/patogenicidade , Genes Bacterianos , Humanos , Linezolida/uso terapêutico
13.
BMC Microbiol ; 19(1): 156, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286887

RESUMO

BACKGROUND: Enterococcus species continues to be an important cause of hospital-acquired infection worldwide. This study was designed to determine the antibiotic resistance profiles, virulence genes and molecular characteristics of Enterococcus faecium strains isolated from an Iranian children hospital in a four-years period. RESULTS: A total 189 Enterococcus strains, comprising 108 (57%) E. faecium, 67 (35%) E. faecalis and 14 (7%) isolates of other spp. were isolated during the collection period. More than 92% of E. faecium isolates were resistant to ampicillin (92.5%), ciprofloxacin (96%), erythromycin (100%) and clindamycin (96%). A high frequency of resistance to clindamycin (100%), erythromycin (98.5%) and ciprofloxacin (80.5%) was observed among E. faecalis isolates, while resistance to ampicillin (7%) was less frequent. The prevalence of vanA gene among vancomycin resistant E. faecium and vancomycin resistant E. faecalis was 95 and 50%, respectively. The analysis of 108 E. faecium isolates revealed 34 variable number tandem repeat (VNTR) patterns and 27 Multi Locus VNTR Analysis (MLVA) types (MTs). CONCLUSIONS: The results show a shift from E. faecalis to E. faecium as the dominant enterococcal species among patients at the children Hospital. Our data revealed that the majority of E. faecium isolates (66%) belonged to three common MTs and these types were isolated from different wards in children hospital.


Assuntos
Farmacorresistência Bacteriana/genética , Enterococcus faecalis , Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Fatores de Virulência/genética , Virulência/genética , Criança , Pré-Escolar , Enterococcus faecalis/genética , Enterococcus faecalis/isolamento & purificação , Enterococcus faecalis/patogenicidade , Enterococcus faecium/genética , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/patogenicidade , Genes Bacterianos , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Irã (Geográfico)
14.
BMC Vet Res ; 15(1): 235, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286947

RESUMO

BACKGROUND: Enterococcus is an important component of normal flora in human and animals, but in recent years, the pathogenicity of Enterococcus has been confirmed in clinical medicine. More and more animal infections have been reported in veterinary clinics. For the last decades, outbreaks of encephalitis in lambs have become much more common in Northern Xinjiang, China. Consequent studies have confirmed that these affected lambs had been commonly infected with E. faecalis. More than 60 E. faecalis were isolated from the brain of infected lambs, A highly virulent strain entitled E. faecalis 2A (XJ05) were selected, sequenced and analyzed. RESULT: Using whole genome sequence and de novo assembly, 18 contigs with NGS and annotation were obtained. It is confirmed that the genome has a size of 2.9 Mb containing 2783 protein-coding genes, as well as 54 tRNA genes and 4 rRNA genes. Some key features of this strain were identified, which included 7 predicted antibiotic resistance genes and 18 candidate virulence factor genes. CONCLUSION: The E. faecalis 2A (XJ05) genome is conspicuous smaller than E.faecalis V583, but not significantly different from other non-pathogenic E. faecalis. It carried 7 resistance genes including 4 kind of antibiotics which were consistent with the results of extensive drug resistance phenotypic, including aminoglycoside, macrolide, phenicol, and tetracycline. 2A (XJ05) also carried 18 new virulence factor genes related to virulence, hemolysin genes (cylA, cylB, cylM, cylL) may play an important role in lamb encephalitis by E. faecalis 2A (XJ05).


Assuntos
Farmacorresistência Bacteriana/genética , Encefalite/veterinária , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Genoma Bacteriano/genética , Doenças dos Ovinos/microbiologia , Virulência/genética , Animais , Resistência a Múltiplos Medicamentos/genética , Encefalite/microbiologia , Ovinos
15.
Int J Antimicrob Agents ; 54(3): 329-337, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31229670

RESUMO

Orthopaedic implant-associated infections are a devastating complication of orthopaedic surgery with a significant impact on patients and healthcare systems. The aims of this work were to describe the patterns of antimicrobial resistance, pathogenicity and virulence of clinical bacterial isolates from orthopaedic implant-associated infections and to further isolate and characterise bacteriophages that are efficient in controlling these bacteria. Staphylococcus aureus, Enterococcus faecalis and Escherichia coli isolated from orthopaedic infections showed multiresistance patterns to the most frequently used antibiotics in clinical settings. The presence of mobile genetic elements (mecA, Tn916/Tn1545 and intl1) and virulence determinants (icaB, cna, hlb, cylLs, cylM, agg, gelE, fsr and fimA) highlighted the pathogenicity of these isolates. Moreover, the isolates belonged to clonal complexes associated with the acquisition of pathogenicity islands and antimicrobial resistance genes by recombination and horizontal gene transfer. Bacteriophages vB_SauM_LM12, vB_EfaS_LM99 and vB_EcoM_JB75 were characterised and their ability to infect clinical isolates of S. aureus, E. faecalis and E. coli, respectively, was assessed. Morphological and genomic analyses revealed that vB_EfaS_LM99 and vB_EcoM_JB75 belong to the Siphoviridae and Myoviridae families, respectively, and no genes associated with lysogeny were found. The bacteriophages showed low latent periods, high burst sizes, broad host ranges and tolerance to several environmental conditions. Moreover, they showed high efficiency and specificity to infect and reduce clinical bacteria, including methicillin-resistant S. aureus and vancomycin-resistant enterococci. Therefore, the results obtained suggest that the bacteriophages used in this work are a promising approach to control these pathogens involved in orthopaedic implant-associated infections.


Assuntos
Bacteriólise , Bacteriófagos/isolamento & purificação , Infecções por Escherichia coli/terapia , Infecções por Bactérias Gram-Positivas/terapia , Terapia por Fagos/métodos , Infecções Relacionadas à Prótese/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriófagos/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/isolamento & purificação , Enterococcus faecalis/patogenicidade , Enterococcus faecalis/virologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Escherichia coli/virologia , Feminino , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Infecções Relacionadas à Prótese/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/virologia
17.
J Mol Biol ; 431(16): 2932-2945, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31132360

RESUMO

Enterococcus faecalis, a ubiquitous member of the healthy human gut microbiota, is also a common opportunistic pathogen and leading cause of nosocomial infections. This tenacious microbe is well adapted to infect and persist in multiple niches within the mammalian host and can rapidly tune its metabolism to respond to new environments, enabling infection in sites including the gastrointestinal tract, urinary tract, wounded epithelium, heart, and blood. In order to withstand and persist in the face of host immune responses, E. faecalis has an arsenal of strategies to suppress, evade, or inactivate innate and adaptive immune mechanisms. In this review, we present the variety of ways E. faecalis modulates the immune response, enabling this otherwise innocuous gut commensal to transition and persist as a pathogen.


Assuntos
Enterococcus faecalis/patogenicidade , Sistema Imunitário/metabolismo , Imunidade Adaptativa , Sangue/imunologia , Sangue/microbiologia , Microbioma Gastrointestinal , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Coração/microbiologia , Humanos , Sistema Imunitário/microbiologia , Imunidade Inata , Sistema Urinário/imunologia , Sistema Urinário/microbiologia
18.
PLoS Pathog ; 15(5): e1007730, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31048927

RESUMO

Enterococcus faecalis is an opportunistic pathogen with an intrinsically high resistance to lysozyme, a key effector of the innate immune system. This high level of resistance requires a complex network of transcriptional regulators and several genes (oatA, pgdA, dltA and sigV) acting synergistically to inhibit both the enzymatic and cationic antimicrobial peptide activities of lysozyme. We sought to identify novel genes modulating E. faecalis resistance to lysozyme. Random transposon mutagenesis carried out in the quadruple oatA/pgdA/dltA/sigV mutant led to the identification of several independent insertions clustered on the chromosome. These mutations were located in a locus referred to as the enterococcal polysaccharide antigen (EPA) variable region located downstream of the highly conserved epaA-epaR genes proposed to encode a core synthetic machinery. The epa variable region was previously proposed to be responsible for EPA decorations, but the role of this locus remains largely unknown. Here, we show that EPA decoration contributes to resistance towards charged antimicrobials and underpins virulence in the zebrafish model of infection by conferring resistance to phagocytosis. Collectively, our results indicate that the production of the EPA rhamnopolysaccharide backbone is not sufficient to promote E. faecalis infections and reveal an essential role of the modification of this surface polymer for enterococcal pathogenesis.


Assuntos
Antígenos de Superfície/imunologia , Enterococcus faecalis/patogenicidade , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/microbiologia , Muramidase/imunologia , Polissacarídeos/imunologia , Virulência , Animais , Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Enterococcus faecalis/genética , Enterococcus faecalis/imunologia , Infecções por Bactérias Gram-Positivas/metabolismo , Muramidase/metabolismo , Mutagênese , Mutação , Polissacarídeos/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/imunologia , Peixe-Zebra/microbiologia
19.
Environ Sci Pollut Res Int ; 26(15): 15105-15114, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30924038

RESUMO

Vancomycin-resistant enterococci (VRE) have been responsible for numerous outbreaks of serious infections in humans worldwide. Enterococcus faecium and Enterococcus faecalis are the principal species that are frequently associated with vancomycin resistance determinants, thus usually implicated in hospital- and community-acquired infections in humans. The study aim was to determine the antibiotic resistance and virulence profiles of VREs isolated from surface and groundwater samples that are used by humans in the North West Province, South Africa. A total of 170 water samples were collected and analyzed. Eighty-one potential isolates were screened for characteristics of Enterococcus species using preliminary biochemical tests, PCR assays and sequence analysis. The antimicrobial resistance profiles of the isolates against nine antibiotics were determined and a dendrogram was generated to access the relatedness of the isolates. The isolates were screened for the presence of antibiotic resistance and virulence genes by multiplex PCR analysis. A total of 56 isolates were confirmed as Enterococcus species and the proportion of E. faecium (46.9%) was higher than E. faecalis (29%) and E. saccharolyticus (1.2%). Sequence data of E. faecium, E. faecalis, and E. saccharolyticus isolates revealed 97 to 98% similarities to clinical strains deposited in NCBI Genbank. Large proportions (44; 78.6%) of the isolates were resistant to vancomycin while 16 and 3.6% of the isolates possessed the vanA and vanB genes respectively. The MAR phenotype Vancomycin-Nalidixic Acid-Streptomycin-Chloramphenicol-Ampicillin-Oxytetracycline-Gentamycin-Nitrofurantoin-Sulphamethoxazole indicated that some isolates were resistant to all of the nine antibiotics tested. Cluster analysis of antibiotic resistance data revealed two major clusters. Sixteen (36.4%), 14 (27.3%), 3 (6.8%), and 2 (4.5%) of the VRE isolates possessed the gel, asa1, hyl, and esp virulence genes respectively while the cylA gene was not detected in the study. Multiple antibiotic-resistant enterococci were also resistant to vancomycin and possessed virulence determinants indicating that they can pose severe public health complications on individuals who consume contaminated water.


Assuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidade , Enterococcus faecium/patogenicidade , Infecções por Bactérias Gram-Positivas/microbiologia , Enterococos Resistentes à Vancomicina/genética , Vancomicina/farmacologia , Fatores de Virulência/análise , Virulência/genética , Enterococcus/química , Enterococcus/efeitos dos fármacos , Enterococcus/patogenicidade , Enterococcus faecalis/química , Enterococcus faecium/química , Enterococcus faecium/genética , Água Subterrânea , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Saúde Pública , África do Sul , Enterococos Resistentes à Vancomicina/química , Fatores de Virulência/genética
20.
J Endod ; 45(3): 295-301.e2, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30803536

RESUMO

INTRODUCTION: Enterococcus faecalis is considered a predominant pathogen for persistent periapical infections and in addition is reportedly resistant to calcium hydroxide medication. The WalRK 2-component system of E. faecalis is essential for environmental adaptation, survival, and virulence. The goal of this study was to investigate the potential roles of walR in the regulation of biofilm aggregation, alkaline stress, and susceptibility to calcium hydroxide (CH) medication. METHODS: Antisense walR RNA (aswalR) overexpression strains were constructed. Exopolysaccharide (EPS) production and bacterial viability of E. faecalis biofilms were evaluated by confocal laser scanning microscopy. Quantitative real-time polymerase chain reaction was used to investigate the expressions of virulent factor genes. The proportion of viable bacteria and EPS production in dentin were assessed after CH medication. RESULTS: We showed that walR interference by aswalR RNA leads to a reduction in the dextran-dependent aggregation in E. faecalis biofilm. The overexpression of aswalR reduced the transcripts of the virulence genes and alkaline stress tolerance ability. Furthermore, the down-regulation of walR sensitized E. faecalis in infected canals to CH medication associated with inhibiting EPS synthesis. CONCLUSIONS: The data suggest a role for the walR regulator in the susceptibility to CH associated with dispelling the EPS matrix, which could be explored as a potential supplementary therapy for the management of root canal infection.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Biofilmes , Hidróxido de Cálcio/farmacologia , Farmacorresistência Bacteriana/genética , Enterococcus faecalis/genética , Enterococcus faecalis/fisiologia , Genes Bacterianos/genética , Genes Bacterianos/fisiologia , Adaptação Fisiológica/genética , Cavidade Pulpar/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/patogenicidade , Humanos , Periodontite Periapical/microbiologia , Pulpite/microbiologia , Virulência/genética
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