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Sample records for enterococcus faeciumstrains reveals

  1. Genetic relationships among Enterococcus faecalis isolates from different sources as revealed by multilocus sequence typing.

    PubMed

    Chen, X; Song, Y Q; Xu, H Y; Menghe, B L G; Zhang, H P; Sun, Z H

    2015-08-01

    Enterococcus faecalis is part of the natural gut flora of humans and other mammals; some isolates are also used in food production. So, it is important to evaluate the genetic diversity and phylogenetic relationships among E. faecalis isolates from different sources. Multilocus sequence typing protocol was used to compare 39 E. faecalis isolates from Chinese traditional food products (including dairy products, acidic gruel) and 4 published E. faecalis isolates from other sources including human-derived isolates employing 5 housekeeping genes (groEL, clpX, recA, rpoB, and pepC). A total of 23 unique sequence types were identified, which were grouped into 5 clonal complexes and 10 singletons. The value of standardized index of association of the alleles (IA(S)=0.1465) and network structure indicated a high frequency of intraspecies recombination across these isolates. Enterococcus faecalis lineages also exhibited clearly source-clustered distributions. The isolates from dairy source were clustered together. However, the relationship between isolates from acidic gruel and one isolate from a human source was close. The MLST scheme presented in this study provides a sharable and continuously growing sequence database enabling global comparison of strains from different sources, and will further advance our understanding of the microbial ecology of this important species.

  2. Drosophila Host Model Reveals New Enterococcus faecalis Quorum-Sensing Associated Virulence Factors

    PubMed Central

    Teixeira, Neuza; Varahan, Sriram; Gorman, Matthew J.; Palmer, Kelli L.; Zaidman-Remy, Anna; Yokohata, Ryoji; Nakayama, Jiro; Hancock, Lynn E.; Jacinto, António; Gilmore, Michael S.; de Fátima Silva Lopes, Maria

    2013-01-01

    Enterococcus faecalis V583 is a vancomycin-resistant clinical isolate which belongs to the hospital-adapted clade, CC2. This strain harbours several factors that have been associated with virulence, including the fsr quorum-sensing regulatory system that is known to control the expression of GelE and SprE proteases. To discriminate between genes directly regulated by Fsr, and those indirectly regulated as the result of protease expression or activity, we compared gene expression in isogenic mutants of V583 variously defective in either Fsr quorum sensing or protease expression. Quorum sensing was artificially induced by addition of the quorum signal, GBAP, exogenously in a controlled manner. The Fsr regulon was found to be restricted to five genes, gelE, sprE, ef1097, ef1351 and ef1352. Twelve additional genes were found to be dependent on the presence of GBAP-induced proteases. Induction of GelE and SprE by GBAP via Fsr resulted in accumulation of mRNA encoding lrgAB, and this induction was found to be lytRS dependent. Drosophila infection was used to discern varying levels of toxicity stemming from mutations in the fsr quorum regulatory system and the genes that it regulates, highlighting the contribution of LrgAB and bacteriocin EF1097 to infection toxicity. A contribution of SprE to infection toxicity was also detected. This work brought to light new players in E. faecalis success as a pathogen and paves the way for future studies on host tolerance mechanisms to infections caused by this important nosocomial pathogen. PMID:23734216

  3. The structure and competitive substrate inhibition of dihydrofolate reductase from Enterococcus faecalis reveal restrictions to cofactor docking.

    PubMed

    Bourne, Christina R; Wakeham, Nancy; Webb, Nicole; Nammalwar, Baskar; Bunce, Richard A; Berlin, K Darrell; Barrow, William W

    2014-02-25

    We are addressing bacterial resistance to antibiotics by repurposing a well-established classic antimicrobial target, the dihydrofolate reductase (DHFR) enzyme. In this work, we have focused on Enterococcus faecalis, a nosocomial pathogen that frequently harbors antibiotic resistance determinants leading to complicated and difficult-to-treat infections. An inhibitor series with a hydrophobic dihydrophthalazine heterocycle was designed from the anti-folate trimethoprim. We have examined the potency of this inhibitor series based on inhibition of DHFR enzyme activity and bacterial growth, including in the presence of the exogenous product analogue folinic acid. The resulting preferences were rationalized using a cocrystal structure of the DHFR from this organism with a propyl-bearing series member (RAB-propyl). In a companion apo structure, we identify four buried waters that act as placeholders for a conserved hydrogen-bonding network to the substrate and indicate an important role in protein stability during catalytic cycling. In these structures, the nicotinamide of the nicotinamide adenine dinucleotide phosphate cofactor is visualized outside of its binding pocket, which is exacerbated by RAB-propyl binding. Finally, homology models of the TMP(R) sequences dfrK and dfrF were constructed. While the dfrK-encoded protein shows clear sequence changes that would be detrimental to inhibitor binding, the dfrF-encoded protein model suggests the protein would be relatively unstable. These data suggest a utility for anti-DHFR compounds for treating infections arising from E. faecalis. They also highlight a role for water in stabilizing the DHFR substrate pocket and for competitive substrate inhibitors that may gain advantages in potency by the perturbation of cofactor dynamics.

  4. The Structure and Competitive Substrate Inhibition of Dihydrofolate Reductase from Enterococcus faecalis Reveal Restrictions to Cofactor Docking

    PubMed Central

    2015-01-01

    We are addressing bacterial resistance to antibiotics by repurposing a well-established classic antimicrobial target, the dihydrofolate reductase (DHFR) enzyme. In this work, we have focused on Enterococcus faecalis, a nosocomial pathogen that frequently harbors antibiotic resistance determinants leading to complicated and difficult-to-treat infections. An inhibitor series with a hydrophobic dihydrophthalazine heterocycle was designed from the anti-folate trimethoprim. We have examined the potency of this inhibitor series based on inhibition of DHFR enzyme activity and bacterial growth, including in the presence of the exogenous product analogue folinic acid. The resulting preferences were rationalized using a cocrystal structure of the DHFR from this organism with a propyl-bearing series member (RAB-propyl). In a companion apo structure, we identify four buried waters that act as placeholders for a conserved hydrogen-bonding network to the substrate and indicate an important role in protein stability during catalytic cycling. In these structures, the nicotinamide of the nicotinamide adenine dinucleotide phosphate cofactor is visualized outside of its binding pocket, which is exacerbated by RAB-propyl binding. Finally, homology models of the TMPR sequences dfrK and dfrF were constructed. While the dfrK-encoded protein shows clear sequence changes that would be detrimental to inhibitor binding, the dfrF-encoded protein model suggests the protein would be relatively unstable. These data suggest a utility for anti-DHFR compounds for treating infections arising from E. faecalis. They also highlight a role for water in stabilizing the DHFR substrate pocket and for competitive substrate inhibitors that may gain advantages in potency by the perturbation of cofactor dynamics. PMID:24495113

  5. Multilocus Sequence Typing Scheme for Enterococcus faecalis Reveals Hospital-Adapted Genetic Complexes in a Background of High Rates of Recombination

    PubMed Central

    Ruiz-Garbajosa, Patricia; Bonten, Marc J. M.; Robinson, D. Ashley; Top, Janetta; Nallapareddy, Sreedhar R.; Torres, Carmen; Coque, Teresa M.; Cantón, Rafael; Baquero, Fernando; Murray, Barbara E.; del Campo, Rosa; Willems, Rob J. L.

    2006-01-01

    A multilocus sequence typing (MLST) scheme based on seven housekeeping genes was used to investigate the epidemiology and population structure of Enterococcus faecalis. MLST of 110 isolates from different sources and geographic locations revealed 55 different sequence types that grouped into four major clonal complexes (CC2, CC9, CC10, and CC21) by use of eBURST. Two of these clonal complexes, CC2 and CC9, are particularly fit in the hospital environment, as CC2 includes the previously described BVE clonal complex identified by an alternative MLST scheme and CC9 includes exclusively isolates from hospitalized patients. Identical alleles were found in genetically diverse isolates with no linkage disequilibrium, while the different MLST loci gave incongruent phylogenetic trees. This demonstrates that recombination is an important mechanism driving genetic variation in E. faecalis and suggests an epidemic population structure for E. faecalis. Our novel MLST scheme provides an excellent tool for investigating local and short-term epidemiology as well as global epidemiology, population structure, and genetic evolution of E. faecalis. PMID:16757624

  6. Multilocus sequence typing scheme for Enterococcus faecalis reveals hospital-adapted genetic complexes in a background of high rates of recombination.

    PubMed

    Ruiz-Garbajosa, Patricia; Bonten, Marc J M; Robinson, D Ashley; Top, Janetta; Nallapareddy, Sreedhar R; Torres, Carmen; Coque, Teresa M; Cantón, Rafael; Baquero, Fernando; Murray, Barbara E; del Campo, Rosa; Willems, Rob J L

    2006-06-01

    A multilocus sequence typing (MLST) scheme based on seven housekeeping genes was used to investigate the epidemiology and population structure of Enterococcus faecalis. MLST of 110 isolates from different sources and geographic locations revealed 55 different sequence types that grouped into four major clonal complexes (CC2, CC9, CC10, and CC21) by use of eBURST. Two of these clonal complexes, CC2 and CC9, are particularly fit in the hospital environment, as CC2 includes the previously described BVE clonal complex identified by an alternative MLST scheme and CC9 includes exclusively isolates from hospitalized patients. Identical alleles were found in genetically diverse isolates with no linkage disequilibrium, while the different MLST loci gave incongruent phylogenetic trees. This demonstrates that recombination is an important mechanism driving genetic variation in E. faecalis and suggests an epidemic population structure for E. faecalis. Our novel MLST scheme provides an excellent tool for investigating local and short-term epidemiology as well as global epidemiology, population structure, and genetic evolution of E. faecalis.

  7. A multi-omic analysis of an Enterococcus faecium mutant reveals specific genetic mutations and dramatic changes in mRNA and protein expression

    PubMed Central

    2013-01-01

    Background For a long time, Enterococcus faecium was considered a harmless commensal of the mammalian gastrointestinal (GI) tract and was used as a probiotic in fermented foods. In recent decades, E. faecium has been recognised as an opportunistic pathogen that causes diseases such as neonatal meningitis, urinary tract infections, bacteremia, bacterial endocarditis and diverticulitis. E. faecium could be taken into space with astronauts and exposed to the space environment. Thus, it is necessary to observe the phenotypic and molecular changes of E. faecium after spaceflight. Results An E. faecium mutant with biochemical features that are different from those of the wild-type strain was obtained from subculture after flight on the SHENZHOU-8 spacecraft. To understand the underlying mechanism causing these changes, the whole genomes of both the mutant and the WT strains were sequenced using Illumina technology. The genomic comparison revealed that dprA, a recombination-mediator gene, and arpU, a gene associated with cell wall growth, were mutated. Comparative transcriptomic and proteomic analyses showed that differentially expressed genes or proteins were involved with replication, recombination, repair, cell wall biogenesis, glycometabolism, lipid metabolism, amino acid metabolism, predicted general function and energy production/conversion. Conclusion This study analysed the comprehensive genomic, transcriptomic and proteomic changes of an E. faecium mutant from subcultures that were loaded on the SHENZHOU-8 spacecraft. The implications of these gene mutations and expression changes and their underlying mechanisms should be investigated in the future. We hope that the current exploration of multiple “-omics” analyses of this E. faecium mutant will provide clues for future studies on this opportunistic pathogen. PMID:24373636

  8. Enterococcus plantarum sp. nov., isolated from plants.

    PubMed

    Svec, Pavel; Vandamme, Peter; Bryndová, Hana; Holochová, Pavla; Kosina, Marcel; Maslanová, Ivana; Sedlácek, Ivo

    2012-07-01

    Eight Gram-positive, catalase-negative bacterial strains were isolated during screening of enterococcal populations on plants. rep-PCR fingerprinting using the (GTG)(5) primer showed that the isolates constituted a single cluster that was separate from all known enterococcal species. 16S rRNA gene sequence phylogenetic analysis of three representative strains showed that the isolates belonged to the genus Enterococcus and that they clustered with the Enterococcus faecalis species group. Sequencing of the genes for the phenylalanyl-tRNA synthase alpha subunit (pheS) and the RNA polymerase alpha subunit (rpoA) also revealed the isolates' separate taxonomic position. Application of whole-cell protein fingerprinting, automated ribotyping and extensive phenotyping demonstrated the genetic and phenotypic homogeneity of the isolates and confirmed their separate position within the E. faecalis species group. The isolates represent a novel species of the genus Enterococcus, for which the name Enterococcus plantarum sp. nov. is proposed; the type strain is CCM 7889(T) (=LMG 26214(T)=C27(T)).

  9. Enterococcus lactis sp. nov., from Italian raw milk cheeses.

    PubMed

    Morandi, Stefano; Cremonesi, Paola; Povolo, Milena; Brasca, Milena

    2012-08-01

    Ten atypical Enterococcus strains were isolated from Italian raw milk cheeses. The 16S rRNA gene, phenylalanyl-tRNA synthase alpha subunit (pheS), RNA polymerase alpha subunit (rpoA) and the 16S-23S rRNA intergenic transcribed spacer (ITS) sequences, randomly amplified polymorphic DNA (RAPD) PCR and the phenotypic properties revealed that the isolates represent a novel enterococcal species. On the basis of 16S rRNA gene sequence analysis, the isolates were closely related to Enterococcus hirae ATCC 8043(T), Enterococcus durans CECT 411(T) and Enterococcus faecium ATCC 19434(T), with 98.8, 98.9 and 99.4% sequence similarity, respectively. On the basis of sequence analysis of the housekeeping gene pheS, the reference strain, BT159(T), occupied a position separate from E. faecium LMG 16198. The group of isolates could be easily differentiated from recognized species of the genus Enterococcus by 16S-23S rRNA ITS analysis, RAPD-PCR and phenotypic characteristics. The name Enterococcus lactis sp. nov. is proposed, with BT159(T) ( = DSM 23655(T) = LMG 25958(T)) as the type strain.

  10. A genomic virulence reference map of Enterococcus faecalis reveals an important contribution of phage03-like elements in nosocomial genetic lineages to pathogenicity in a Caenorhabditis elegans infection model.

    PubMed

    La Rosa, Sabina Leanti; Snipen, Lars-Gustav; Murray, Barbara E; Willems, Rob J L; Gilmore, Michael S; Diep, Dzung B; Nes, Ingolf F; Brede, Dag Anders

    2015-05-01

    In the present study, the commensal and pathogenic host-microbe interaction of Enterococcus faecalis was explored using a Caenorhabditis elegans model system. The virulence of 28 E. faecalis isolates representing 24 multilocus sequence types (MLSTs), including human commensal and clinical isolates as well as isolates from animals and of insect origin, was investigated using C. elegans strain glp-4 (bn2ts); sek-1 (km4). This revealed that 6 E. faecalis isolates behaved in a commensal manner with no nematocidal effect, while the remaining strains showed a time to 50% lethality ranging from 47 to 120 h. Principal component analysis showed that the difference in nematocidal activity explained 94% of the variance in the data. Assessment of known virulence traits revealed that gelatinase and cytolysin production accounted for 40.8% and 36.5% of the observed pathogenicity, respectively. However, coproduction of gelatinase and cytolysin did not increase virulence additively, accounting for 50.6% of the pathogenicity and therefore indicating a significant (26.7%) saturation effect. We employed a comparative genomic analysis approach using the 28 isolates comprising a collection of 82,356 annotated coding sequences (CDS) to identify 2,325 patterns of presence or absence among the investigated strains. Univariate statistical analysis of variance (ANOVA) established that individual patterns positively correlated (n = 61) with virulence. The patterns were investigated to identify potential new virulence traits, among which we found five patterns consisting of the phage03-like gene clusters. Strains harboring phage03 showed, on average, 17% higher killing of C. elegans (P = 4.4e(-6)). The phage03 gene cluster was also present in gelatinase-and-cytolysin-negative strain E. faecalis JH2-2. Deletion of this phage element from the JH2-2 clinical strain rendered the mutant apathogenic in C. elegans, and a similar mutant of the nosocomial V583 isolate showed significantly attenuated

  11. Bacteriocin from Honeybee Beebread Enterococcus avium, Active against Listeria monocytogenes

    PubMed Central

    Audisio, M. Carina; Terzolo, Horacio R.; Apella, María C.

    2005-01-01

    Enterococcus avium isolated from Apis mellifera beebread produces a thermoresistant bacteriocin with a strain-dependent inhibitory effect on Listeria and without effect on gram-negative bacteria. The bacteriocin appeared to be a polypeptide of about 6 kDa. Genetic analyses revealed no extrachromosomal material in E. avium. PMID:15933045

  12. Dissemination of Enterococcus faecalis and Enterococcus faecium in a ricotta processing plant and evaluation of pathogenic and antibiotic resistance profiles.

    PubMed

    Fernandes, Meg da Silva; Fujimoto, Graciela; de Souza, Leandro Pio; Kabuki, Dirce Yorika; da Silva, Márcio José; Kuaye, Arnaldo Yoshiteru

    2015-04-01

    In this work, the sources of contamination by Enterococcus spp. in a ricotta processing line were evaluated. The isolated strains were tested for virulence genes (gelE, cylA,B, M, esp, agg, ace, efaA, vanB), expression of virulence factors (hemolysin and gelatinase), and the resistance to 10 different antibiotics. Enterococcus faecium and Enterococcus faecalis were subjected to discriminatory identification by intergenic spacer region (ITS)-polymerase chain reaction and sequencing of the ITS region. The results showed that Enterococcus spp. was detected in the raw materials, environment samples and the final product. None of the 107 Enterococcus isolates were completely free from all virulence genes considered. A fraction of 21.5% of the isolates containing all of the genes of the cylA, B, M operon also expressed β-hemolysis. Most of the isolates showed the gelE gene, but only 9.3% were able to hydrolyze gelatin. In addition, 23.5% of the observed Enterococcus isolates had the vanB gene but were susceptible to vancomycin in vitro. The dissemination of antibiotic-resistant enterococci was revealed in this study: 19.3% of the E. faecium samples and 78.0% of the E. faecalis samples were resistant to at least one of the antibiotics tested. Sequencing of region discriminated 5 and 7 distinct groups among E. faecalis and E. faecium, respectively. Although some similarity was observed among some of the isolates, all E. faecalis and E. faecium isolates had genetic differences both in the ITS region and in the virulence profile, which makes them different from each other.

  13. Antibiotic resistance, efflux pump genes and virulence determinants in Enterococcus spp. from surface water systems.

    PubMed

    Molale, L G; Bezuidenhout, Cornelius Carlos

    2016-11-01

    The aim of this study was to report on antibiotic susceptibility patterns as well as highlight the presence of efflux pump genes and virulence genetic determinants in Enterococcus spp. isolated from South African surface water systems. One hundred and twenty-four Enterococcus isolates consisting of seven species were identified. Antimicrobial susceptibility testing revealed a high percentage of isolates was resistant to β-lactams and vancomycin. Many were also resistant to other antibiotic groups. These isolates were screened by PCR, for the presence of four efflux pump genes (mefA, tetK, tetL and msrC). Efflux genes mefA and tetK were not detected in any of the Enterococcus spp. However, tetL and msrC were detected in 17 % of the Enterococcus spp. The presence of virulence factors in the Enterococcus spp. harbouring efflux pump genes was determined. Virulence determinants were detected in 86 % of the Enterococcus spp. harbouring efflux pump genes. Four (asa1, cylA, gel and hyl) of the five virulence factors were detected. The findings of this study have demonstrated that Enterococcus from South African surface water systems are resistant to multiple antibiotics, some of which are frequently used for therapy. Furthermore, these isolates harbour efflux pump genes coding for resistance to antibiotics and virulence factors which enhance their pathogenic potential.

  14. Enterococcal meningitis caused by Enterococcus casseliflavus. First case report

    PubMed Central

    Iaria, Chiara; Stassi, Giovanna; Costa, Gaetano Bruno; Di Leo, Rita; Toscano, Antonio; Cascio, Antonio

    2005-01-01

    Background Enterococcal meningitis is an uncommon disease usually caused by Enterococcus faecalis and Enterococcus faecium and is associated with a high mortality rate. Enterococcus casseliflavus has been implicated in a wide variety of infections in humans, but never in meningitis. Case presentation A 77-year-old Italian female presented for evaluation of fever, stupor, diarrhea and vomiting of 3 days duration. There was no history of head injury nor of previous surgical procedures. She had been suffering from rheumatoid arthritis for 30 years, for which she was being treated with steroids and methotrexate. On admission, she was febrile, alert but not oriented to time and place. Her neck was stiff, and she had a positive Kernig's sign. The patient's cerebrospinal fluid was opalescent with a glucose concentration of 14 mg/dl, a protein level of 472 mg/dl, and a white cell count of 200/μL with 95% polymorphonuclear leukocytes and 5% lymphocytes. Gram staining of CSF revealed no organisms, culture yielded E. casseliflavus. The patient was successfully treated with meropenem and ampicillin-sulbactam. Conclusions E. casseliflavus can be inserted among the etiologic agents of meningitis. Awareness of infection of central nervous system with Enterococcus species that possess an intrinsic vancomycin resistance should be increased. PMID:15649336

  15. Enterococcus alcedinis sp. nov., isolated from common kingfisher (Alcedo atthis).

    PubMed

    Frolková, Petra; Švec, Pavel; Sedláček, Ivo; Mašlaňová, Ivana; Černohlávková, Jitka; Ghosh, Anuradha; Zurek, Ludek; Radiměřský, Tomáš; Literák, Ivan

    2013-08-01

    Two Gram-positive, catalase-negative bacterial strains were isolated from the cloaca of common kingfishers (Alcedo atthis). Repetitive sequence-based PCR fingerprinting using the (GTG)5 primer grouped these isolates into a single cluster separated from all known enterococcal species. The two strains revealed identical 16S rRNA gene sequences placing them within the genus Enterococcus with Enterococcus aquimarinus LMG 16607(T) as the closest relative (97.14 % similarity). Further taxonomic investigation using sequencing of the genes for the superoxide dismutase (sodA), phenylalanyl-tRNA synthase alpha subunit (pheS) and the RNA polymerase alpha subunit (rpoA) as well as application of whole-cell protein fingerprinting, automated ribotyping and extensive phenotyping confirmed that both strains belong to the same species. Based on data from this polyphasic study, these strains represent a novel species of the genus Enterococcus, for which the name Enterococcus alcedinis sp. nov. is proposed. The type strain is L34(T) (= CCM 8433(T) = LMG 27164(T)).

  16. Purification and characterization of enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4.

    PubMed Central

    Joosten, H M; Nunez, M; Devreese, B; Van Beeumen, J; Marugg, J D

    1996-01-01

    A simple two-step procedure was developed to obtain pure enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4. Chemical and genetic characterization revealed that the primary structure of enterocin 4 is identical to that of peptide antibiotic AS-48 from Enterococcus faecalis S-48. In contrast to the reported inhibitory spectrum of AS-48, enterocin 4 displayed no activity against gram-negative bacteria. PMID:8900014

  17. Complete Genome Sequences of Enterococcus rotai LMG 26678T and Enterococcus silesiacus LMG 23085T

    PubMed Central

    Lauer, Ana C.; Humrighouse, Ben W.; Loparev, Vladimir; Shewmaker, Patricia L.; McQuiston, John R.; McLaughlin, Richard W.

    2016-01-01

    The inclusion of molecular methods in the characterization of the novel species Enterococcus horridus necessitated the sequencing and assembly of the genomes of the closely related Enterococcus rotai and Enterococcus silesiacus. Sequencing using Illumina technology in combination with optical mapping led to the generation of closed genomes for both isolates. PMID:27979941

  18. Enterococcus species diversity and molecular characterization of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands, India.

    PubMed

    Meena, Balakrishnan; Anburajan, Lawrance; Sathish, Thadikamala; Raghavan, Rangamaran Vijaya; Jha, Dilip Kumar; Venkateshwaran, Pitchiah; Das, Apurba Kumar; Dheenan, Palaiya Sukumaran; Vinithkumar, Nambali Valsalan; Dharani, Gopal; Kirubagaran, Ramalingam

    2015-05-15

    This study was performed to evaluate the abundance and diversity of Enterococcus sp. and the distribution of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands. The Enterococcus sp. densities at the seven sampling stations were highly influenced by tidal fluctuations and season. The distributions and diversities of species varied in the inner and outer regions of Port Blair Bay. Among the 1816 total isolates, the occurrence of fecal Enterococcus was high (1.78×10(4) CFU/100 mL) in Phoenix Bay. Moreover, 67.76% of the isolates were identified as Enterococcus, and the most frequently identified species were E. hirae, E. avium and E. faecalis. Assessments of antibiotic resistance and biomarker genes revealed the maximum occurrence in the Aberdeen Bay isolates. The most prevalent biomarker genes observed in the E. faecalis isolates were gelE and asa1, whereas cyl was not found among the isolates. In silico sequence analysis of biomarker genes of E. faecalis also revealed that they are evolutionarily well conserved with those of earlier reports. Further, multivariate analysis distinguished the JB, PB and OS stations from the other stations according to distinctive microbial densities and compositions. In addition, the Shannon-Wiener diversity indices and box-whisker plots further facilitated and supported the multivariate results.

  19. Determination of the nucleotide sequence of the 23S ribosomal RNA and flanking spacers of an Enterococcus faecium strain, reveals insertion-deletion events in the ribosomal spacer 1 of enterococci.

    PubMed

    Naimi, A; Beck, G; Monique, M; Lefèbvre, G; Branlanti, C

    1999-02-01

    The usefulness of 16S-23S (ITS1) and 23S-5S (ITS2) ribosomal spacer nucleotide sequence determination, as a complementary approach to the biochemical tests traditionally used for enterococcal species identification, is shown by its application to the identification of a strain, E27, isolated from a natural bacteria mixture used for cheese production. Using combined approaches we showed, unambiguously, that strain E27 belongs to the Enterococcus faecium species. However, its ITS1 region has an interesting peculiarity. In our previous study of ITS1s from various enterococcal species (NAIMI et al., 1997, Microbiology 143, 823-834), the ITS1s of the two E. faecium strains studied, were found to contain an additional 115-nt long stem-loop structure as compared to the ITS1s of other enterococci, only one out of the 3 ITS1s of E. hirae ATCC 9790, was found to contain a similar 107-nt long stem-loop structure. The ITS1 of strain E27 is 100% identical to that of E. faecium ATCC 19434T, except that the 115-nt additional fragment is absent. This strongly suggests the existence of lateral DNA transfer or DNA recombination events at a hot spot position of the ITS1s from E. faecium and E. hirae. Small and large ITS1 nucleotide sequence determination for strain E27 generalized the notion of two kinds of ITSs in enterococci: one with a tRNA(Ala) gene, one without tRNA gene. To complete strain E27 characterization, its 23S rRNA sequence was established. This is the first complete 23S rRNA nucleotide sequence determined for an enterococcal species.

  20. Transcriptional response of Enterococcus faecalis to sunlight.

    PubMed

    Sassoubre, Lauren M; Ramsey, Matthew M; Gilmore, Michael S; Boehm, Alexandria B

    2014-01-05

    Microarrays were used to investigate the transcriptional response of Enterococcus faecalis to photostress. E. faecalis are Gram-positive bacteria used as indicators of water quality and have been shown to vary diurnally in response to sunlight. E. faecalis in filtered seawater microcosms were exposed to artificial sunlight for 12h and then placed in the dark for 12h. Transcript abundance was measured at 0, 2, 6, 12, and 24h in the sunlit microcosm and a dark control using microarrays. Culturable E. faecalis concentrations decreased 6-7 orders of magnitude within the first 6h of light exposure. After 12h in the dark, no evidence of dark-repair was observed. Expression data collected after 12h of sunlight exposure revealed a difference in transcript abundance in the light relative to dark microcosms for 35 unique ORFs, 33 ORFs showed increased transcript abundance and 2 ORFs showed reduced transcript abundance. A majority (51%) of the ORFs with increased transcript abundance in the sunlit relative to dark microcosms encoded hypothetical proteins; others were associated with protein synthesis, oxidative stress and DNA repair. Results suggest that E. faecalis exposed to sunlight actively transcribe RNA in response to photostress.

  1. Targeting Enterococcus faecalis Biofilms with Phage Therapy

    PubMed Central

    Khalifa, Leron; Brosh, Yair; Gelman, Daniel; Coppenhagen-Glazer, Shunit; Beyth, Shaul; Poradosu-Cohen, Ronit; Que, Yok-Ai; Beyth, Nurit

    2015-01-01

    Phage therapy has been proven to be more effective, in some cases, than conventional antibiotics, especially regarding multidrug-resistant biofilm infections. The objective here was to isolate an anti-Enterococcus faecalis bacteriophage and to evaluate its efficacy against planktonic and biofilm cultures. E. faecalis is an important pathogen found in many infections, including endocarditis and persistent infections associated with root canal treatment failure. The difficulty in E. faecalis treatment has been attributed to the lack of anti-infective strategies to eradicate its biofilm and to the frequent emergence of multidrug-resistant strains. To this end, an anti-E. faecalis and E. faecium phage, termed EFDG1, was isolated from sewage effluents. The phage was visualized by electron microscopy. EFDG1 coding sequences and phylogeny were determined by whole genome sequencing (GenBank accession number KP339049), revealing it belongs to the Spounavirinae subfamily of the Myoviridae phages, which includes promising candidates for therapy against Gram-positive pathogens. This analysis also showed that the EFDG1 genome does not contain apparent harmful genes. EFDG1 antibacterial efficacy was evaluated in vitro against planktonic and biofilm cultures, showing effective lytic activity against various E. faecalis and E. faecium isolates, regardless of their antibiotic resistance profile. In addition, EFDG1 efficiently prevented ex vivo E. faecalis root canal infection. These findings suggest that phage therapy using EFDG1 might be efficacious to prevent E. faecalis infection after root canal treatment. PMID:25662974

  2. Targeting Enterococcus faecalis biofilms with phage therapy.

    PubMed

    Khalifa, Leron; Brosh, Yair; Gelman, Daniel; Coppenhagen-Glazer, Shunit; Beyth, Shaul; Poradosu-Cohen, Ronit; Que, Yok-Ai; Beyth, Nurit; Hazan, Ronen

    2015-04-01

    Phage therapy has been proven to be more effective, in some cases, than conventional antibiotics, especially regarding multidrug-resistant biofilm infections. The objective here was to isolate an anti-Enterococcus faecalis bacteriophage and to evaluate its efficacy against planktonic and biofilm cultures. E. faecalis is an important pathogen found in many infections, including endocarditis and persistent infections associated with root canal treatment failure. The difficulty in E. faecalis treatment has been attributed to the lack of anti-infective strategies to eradicate its biofilm and to the frequent emergence of multidrug-resistant strains. To this end, an anti-E. faecalis and E. faecium phage, termed EFDG1, was isolated from sewage effluents. The phage was visualized by electron microscopy. EFDG1 coding sequences and phylogeny were determined by whole genome sequencing (GenBank accession number KP339049), revealing it belongs to the Spounavirinae subfamily of the Myoviridae phages, which includes promising candidates for therapy against Gram-positive pathogens. This analysis also showed that the EFDG1 genome does not contain apparent harmful genes. EFDG1 antibacterial efficacy was evaluated in vitro against planktonic and biofilm cultures, showing effective lytic activity against various E. faecalis and E. faecium isolates, regardless of their antibiotic resistance profile. In addition, EFDG1 efficiently prevented ex vivo E. faecalis root canal infection. These findings suggest that phage therapy using EFDG1 might be efficacious to prevent E. faecalis infection after root canal treatment.

  3. Enterococcus casseliflavus and Enterococcus gallinarum as causative agents of spontaneous bacterial peritonitis.

    PubMed

    Narciso-Schiavon, Janaína Luz; Borgonovo, Ariane; Marques, Paula Couto; Tonon, Débora; Bansho, Emilia Tiemi Oshiro; Maggi, Dariana Carla; Dantas-Corrêa, Esther Buzaglo; de Lucca Schiavon, Leonardo

    2015-01-01

    Infection by multidrug resistant bacteria is arousing as a relevant issue among hospitalized subjects and is of particular interest in patients with cirrhosis given the frequent use of broad spectrum antibiotics and their altered immune response. We report the first case report of spontaneous bacterial peritonitis (SBP) caused by Enterococcus casseliflavus and the sixth case of SBP caused by Enterococcus gallinarum.

  4. Genetic Diversity among Enterococcus faecalis

    PubMed Central

    McBride, Shonna M.; Fischetti, Vincent A.; LeBlanc, Donald J.; Moellering, Robert C.; Gilmore, Michael S.

    2007-01-01

    Enterococcus faecalis, a ubiquitous member of mammalian gastrointestinal flora, is a leading cause of nosocomial infections and a growing public health concern. The enterococci responsible for these infections are often resistant to multiple antibiotics and have become notorious for their ability to acquire and disseminate antibiotic resistances. In the current study, we examined genetic relationships among 106 strains of E. faecalis isolated over the past 100 years, including strains identified for their diversity and used historically for serotyping, strains that have been adapted for laboratory use, and isolates from previously described E. faecalis infection outbreaks. This collection also includes isolates first characterized as having novel plasmids, virulence traits, antibiotic resistances, and pathogenicity island (PAI) components. We evaluated variation in factors contributing to pathogenicity, including toxin production, antibiotic resistance, polymorphism in the capsule (cps) operon, pathogenicity island (PAI) gene content, and other accessory factors. This information was correlated with multi-locus sequence typing (MLST) data, which was used to define genetic lineages. Our findings show that virulence and antibiotic resistance traits can be found within many diverse lineages of E. faecalis. However, lineages have emerged that have caused infection outbreaks globally, in which several new antibiotic resistances have entered the species, and in which virulence traits have converged. Comparing genomic hybridization profiles, using a microarray, of strains identified by MLST as spanning the diversity of the species, allowed us to identify the core E. faecalis genome as consisting of an estimated 2057 unique genes. PMID:17611618

  5. Enterococcus saccharominimus sp. nov., from dairy products.

    PubMed

    Vancanneyt, M; Zamfir, M; Devriese, L A; Lefebvre, K; Engelbeen, K; Vandemeulebroecke, K; Amar, M; De Vuyst, L; Haesebrouck, F; Swings, J

    2004-11-01

    Four isolates, which were obtained from Belgian, Moroccan and Romanian dairy products, constituted a homogeneous but unidentified taxon after screening with whole-cell protein fingerprinting. Complete 16S rRNA gene sequence analysis classified representative strains in the genus Enterococcus. Highest sequence similarities of 98.6 and 98.0 % were obtained with the species Enterococcus sulfureus and Enterococcus saccharolyticus, respectively. Growth characteristics, biochemical features, tRNA intergenic length polymorphism analysis, DNA-DNA hybridization and DNA G+C contents of selected strains demonstrated that they represent a single, novel Enterococcus species. It differs phenotypically from other enterococci in characteristics commonly considered as typical of this genus: no growth in 6.5 % NaCl or 0.4 % sodium azide, and no acid production from a wide range of carbohydrates. The name Enterococcus saccharominimus sp. nov. is proposed for this novel species; the type strain (LMG 21727(T)=CCM 7220(T)) was isolated from contaminated pasteurized cow's milk.

  6. [Comparison of microdilution method and Phoenix automated system for testing antimicrobial susceptibilities of Enterococcus strains].

    PubMed

    Gülmez, Dolunay; Hasçelik, Gülşen

    2011-01-01

    Enterococcus spp. are important pathogens which are intrinsically resistant to most of the commonly used antimicrobial agents such as aminoglycosides and cephalosporins. Accurate determination of resistance is important to ensure appropriate antimicrobial therapy. This study was undertaken to compare the susceptibility results obtained by Phoenix system (Becton Dickinson, USA) with reference microdilution method. We included 1248 Enterococcus spp. (903 Enterococcus faecalis, 345 Enterococcus faecium) strains isolated from clinical samples between 2005-2007 in routine microbiology laboratory of Hacettepe University Hospital. The strains were identified and the antimicrobial susceptibilities were determined by the Phoenix system. Antimicrobial susceptibilities to ampicillin, teicoplanin, vancomycin, gentamicin and streptomycin were also studied by microdilution method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Evaluation revealed excellent agreement for all of the antibiotics with category agreement rates of > 97%. Among 1248 strains, 76 revealed discordant results. Very major error rates were 1.5% for ampicillin, 1.3% for gentamicin, and 0.9% for streptomycin. Major error rates were 1.4% for streptomycin, 0.6% for ampicillin and vancomycin and 0.3% for gentamicin. Minor error rates were found as 0.2% for vancomycin, and 0.1% for teicoplanin. Resistance rates obtained by microdilution were as follows; high level streptomycin 44%, high level gentamicin 29.7%, ampicillin 25.6%, vancomycin 2.2% and teicoplanin 2.2%. Resistance rates were higher in E.faecium than E.faecalis and 96.4% of the vancomycin resistant enterococcus isolates were identified as E.faecium. In conclusion, based on the data obtained, Phoenix system is reliable for testing susceptibilities of Enterococcus spp. to these antimicrobials. Since isolation of vancomycin resistant enterococci has an important impact in terms of hospital infection control, vancomycin

  7. Experimental study of the impact of antimicrobial treatments on Campylobacter, Enterococcus and PCR-capillary electrophoresis single-strand conformation polymorphism profiles of the gut microbiota of chickens.

    PubMed

    Mourand, Gwenaëlle; Jouy, Eric; Bougeard, Stéphanie; Dheilly, Alexandra; Kérouanton, Annaëlle; Zeitouni, Salman; Kempf, Isabelle

    2014-11-01

    An experiment was conducted to compare the impact of antimicrobial treatments on the susceptibility of Campylobacter, Enterococcus faecium and Enterococcus faecalis, and on the diversity of broiler microbiota. Specific-pathogen-free chickens were first orally inoculated with strains of Campylobacter and Enterococcus faecium. Birds were then orally treated with recommended doses of oxytetracycline, sulfadimethoxine/trimethoprim, amoxicillin or enrofloxacin. Faecal samples were collected before, during and after antimicrobial treatment. The susceptibility of Campylobacter, Enterococcus faecium and Enterococcus faecalis strains isolated on supplemented or non-supplemented media was studied and PCR-capillary electrophoresis single-strand conformation polymorphism (CE-SSCP) profiles of the gut microbiota were analysed. Enrofloxacin-resistant Campylobacter were selected in the enrofloxacin-treated group and showed the Thr86Ile mutation in the gyrA gene. Acquisition of the tetO gene in Campylobacter coli isolates was significantly more frequent in birds given oxytetracycline. No impact of amoxicillin treatment on the susceptibility of Campylobacter could be detected. Ampicillin- and sulfadimethoxine/trimethoprim-resistant Enterococcus faecium were selected in amoxicillin-treated broilers, but no selection of the inoculated vancomycin-resistant Enterococcus faecium could be detected, although it was also resistant to tetracycline and sulfadimethoxine/trimethoprim. PCR-CE-SSCP revealed significant variations in a few peaks in treated birds as compared with non-treated chickens. In conclusion, antimicrobial treatments perturbed chicken gut microbiota, and certain antimicrobial treatments selected or co-selected resistant strains of Campylobacter and Enterococcus.

  8. Antimicrobial Susceptibility Patterns of Enterococcus faecalis and Enterococcus faecium Isolated from Poultry Flocks in Germany.

    PubMed

    Maasjost, J; Mühldorfer, K; Cortez de Jäckel S; Hafez, H M

    2015-03-01

    Between 2010 and 2011, 145 Enterococcus isolates (Enterococcus faecalis, n = 127; Enterococcus faecium, n = 18) were collected during routine bacteriologic diagnostics from broilers, layers, and fattening turkeys in Germany showing various clinical signs. The susceptibility to 24 antimicrobial agents was investigated by broth microdilution test to determine minimum inhibitory concentrations (MICs). All E. faecalis isolates (n = 127) were susceptible to the beta-lactam antibiotics ampicillin, amoxicillin-clavulanic acid, and penicillin. Corresponding MIC with 50% inhibition (MIC50) and MIC with 90% inhibition (MIC90) values of these antimicrobial agents were at the lower end of the test range (≤ 4 μg/ml). In addition, no vancomycin-resistant enterococci (VRE) were found. High resistance rates were identified in both Enterococcus species for lincomycin (72%-99%) and tetracycline (67%-82%). Half or more than half of Enterococcus isolates were resistant to gentamicin (54%-72%) and the macrolide antibiotics erythromycin (44%-61%) and tylosin-tartate (44%-56%). Enterococcus faecalis isolated from fattening turkeys showed the highest prevalence of antimicrobial resistance compared to other poultry production systems. Eighty-nine out of 145 Enterococcus isolates were resistant to three or more antimicrobial classes. Again, turkeys stood out with 42 (8 1%) multiresistant isolates. The most-frequent resistance patterns of E. faecalis were gentamicin, lincomycin, and tetracycline in all poultry production systems.

  9. Characterization of monolaurin resistance in Enterococcus faecalis.

    PubMed

    Dufour, Muriel; Manson, Janet M; Bremer, Philip J; Dufour, Jean-Pierre; Cook, Gregory M; Simmonds, Robin S

    2007-09-01

    There is increasing concern regarding the presence of vancomycin-resistant enterococci in domestically farmed animals, which may act as reservoirs and vehicles of transmission for drug-resistant enterococci to humans, resulting in serious infections. In order to assess the potential for the use of monolaurin as a food preservative, it is important to understand both its target and potential mechanisms of resistance. A Tn917 mutant library of Enterococcus faecalis AR01/DGVS was screened for resistance (MIC, >100 microg/ml) to monolaurin. Three mutants were identified as resistant to monolaurin and were designated DGRM2, DGRM5, and DGRM12. The gene interrupted in all three mutants was identified as traB, which encodes an E. faecalis pheromone shutdown protein and whose complementation in trans restored monolaurin sensitivity in all three mutants. DGRM2 was selected for further characterization. E. faecalis DGRM2 showed increased resistance to gentamicin and chloramphenicol (inhibitors of protein synthesis), while no difference in the MIC was observed with the cell wall-active antibiotics penicillin and vancomycin. E. faecalis AR01/DGVS and DGRM2 were shown to have similar rates (30% cell lysis after 4 h) of cell autolytic activity when activated by monolaurin. Differences in cell surface hydrophobicity were observed between the wild type and the mutant, with the cell surface of the parent strain being significantly more hydrophobic. Analysis of the cell wall structure of DGRM2 by transmission electron microscopy revealed an increase in the apparent cell wall thickness and contraction of its cytoplasm. Taken together, these results suggest that the increased resistance of DGRM2 was due to a change in cell surface hydrophobicity, consequently limiting the diffusion of monolaurin to a potential target in the cytoplasmic membrane and/or cytoplasm of E. faecalis.

  10. Mature biofilms of Enterococcus faecalis and Enterococcus faecium are highly resistant to antibiotics.

    PubMed

    Holmberg, Anna; Rasmussen, Magnus

    2016-01-01

    Enterococcus faecalis and Enterococcus faecium are important nosocomial pathogens that form biofilms on implanted materials. We compare the antibiotic sensitivity of bacteria in new (established during 24 hours) and mature (established during 120 hours) enterococcal biofilms. Mature biofilms contained more bacteria and were much more tolerant to antibiotics, including rifampicin-containing combinations, as judged by determination of minimal biofilm eradication concentrations and by time-kill experiments of bacteria in biofilms formed on beads of bone cement.

  11. 9230 FECAL ENTEROCOCCUS/STREPTOCOCCUS GROUPS

    EPA Science Inventory

    In 1903 the genus name Enterococcus was proposed for gram-positive, catalase-negative, coccoid-shaped bacterial of intestinal origin. Several years later, it was suggested that the genus name be changed to Streptococcus because of the organisms' ability to form chains of coccoid...

  12. Emphysematous pyometra secondary to Enterococcus avium infection in a dog.

    PubMed

    Chang, An-Chi; Cheng, Ching-Chang; Wang, Hsien-Chi; Lee, Wei-Ming; Shyu, Ching-Lin; Lin, Cheng-Chung; Chen, Kuan-Sheng

    2016-06-16

    A 5-year-old female intact Mastiff dog was presented with a history of vaginal discharge for 1 day. Physical examination revealed a sanguineo-purulent vaginal discharge and systemic inflammatory response syndrome. Abdominal radiographs showed several dilated and gas- filled tubular loops. The differential diagnoses included emphysematous pyometra or small intestinal mechanical ileus. Surgical exploration of the abdomen demonstrated a severely dilated and gas-filled uterus, and emphysematous pyometra was confirmed. The patient's clinical signs resolved after ovariohysterectomy. Histopathology revealed mild endometrial cystic hyperplasia with infiltration of inflammatory cells in the superficial endometrial epithelia. Enterococcus avium, an α-hemolytic gram-positive coccus, was isolated from the uterus. This paper highlights the radiographic features of emphysematous pyometra and a pathogen that has never been reported to be associated with canine pyometra previously.

  13. Nonclinical and Clinical Enterococcus faecium Strains, but Not Enterococcus faecalis Strains, Have Distinct Structural and Functional Genomic Features

    PubMed Central

    Kim, Eun Bae

    2014-01-01

    Certain strains of Enterococcus faecium and Enterococcus faecalis contribute beneficially to animal health and food production, while others are associated with nosocomial infections. To determine whether there are structural and functional genomic features that are distinct between nonclinical (NC) and clinical (CL) strains of those species, we analyzed the genomes of 31 E. faecium and 38 E. faecalis strains. Hierarchical clustering of 7,017 orthologs found in the E. faecium pangenome revealed that NC strains clustered into two clades and are distinct from CL strains. NC E. faecium genomes are significantly smaller than CL genomes, and this difference was partly explained by significantly fewer mobile genetic elements (ME), virulence factors (VF), and antibiotic resistance (AR) genes. E. faecium ortholog comparisons identified 68 and 153 genes that are enriched for NC and CL strains, respectively. Proximity analysis showed that CL-enriched loci, and not NC-enriched loci, are more frequently colocalized on the genome with ME. In CL genomes, AR genes are also colocalized with ME, and VF are more frequently associated with CL-enriched loci. Genes in 23 functional groups are also differentially enriched between NC and CL E. faecium genomes. In contrast, differences were not observed between NC and CL E. faecalis genomes despite their having larger genomes than E. faecium. Our findings show that unlike E. faecalis, NC and CL E. faecium strains are equipped with distinct structural and functional genomic features indicative of adaptation to different environments. PMID:24141120

  14. Environmental waters as a source of antibiotic-resistant Enterococcus species in Belgrade, Serbia.

    PubMed

    Veljović, Katarina; Popović, Nikola; Vidojević, Amarela Terzić; Tolinački, Maja; Mihajlović, Sanja; Jovčić, Branko; Kojić, Milan

    2015-09-01

    Despite the number of studies on antibiotic-resistant enterococci from Serbian clinical settings, there are no data about environmental contamination with these bacteria. Thus, this study investigated the prevalence of antibiotic-resistant enterococci in Belgrade, Serbia. Enterococcus species collected from ten surface water sites, including a lake, two major river systems, and springs, were tested. Among enterococci, we found single (21.7 %), double (17.4 %), and multiple antibiotic resistance patterns (56.3 %). Vancomycin-resistant strains were not found, indicating that their abundance in Belgrade is tightly linked to clinical settings. The multiple drug-resistant strains Enterococcus faecalis, Enterococcus faecium, and Enterococcus mundtii were frequently detected in the lake during the swimming season and in the rivers near industrial zones. We confirmed the presence of ermB, ermC, ant(6)-Ia, tetM, and tetL and mutations in gyrA genes. The phylogenetic analysis of 16S rRNA gene of E. faecium isolates that harbor esp gene classified them into two groups based on high-bootstraps scores in the tree analysis. Pulsed-field gel electrophoresis analysis of antibiotic-resistant enterococci revealed genomic similarity ranging from 75 to 100 %. This study indicates the importance of anthropogenic impact to the spread of antibiotic-resistant enterococci in environmental waters of Belgrade, Serbia.

  15. Enterococcus olivae sp. nov., isolated from Spanish-style green-olive fermentations.

    PubMed

    Lucena-Padrós, Helena; González, Juan M; Caballero-Guerrero, Belén; Ruiz-Barba, José Luis; Maldonado-Barragán, Antonio

    2014-08-01

    Six strains of a hitherto unknown, Gram-stain-positive coccus were recovered from samples of Spanish-style green-olive fermentations. The 16S rRNA gene sequences from these isolates shared 98.7% and 98.5% of their nucleotide positions with those from Enterococcus saccharolyticus subsp. taiwanensis 812(T) and from E. saccharolyticus subsp. saccharolyticus ATCC 43076(T), respectively. The sequence of the rpoA gene in the isolates was 95% similar to that of E. saccharolyticus CECT 4309(T) ( = ATCC 43076(T)). The 16S rRNA and rpoA gene phylogenies revealed that the isolates grouped in a statistically well-supported cluster separate from E. saccharolyticus. Enzyme activity profiles as well as fermentation patterns differentiated the novel bacteria from other members of the Enterococcus genus. Finally, phenotypic, genotypic and phylogenetic data supported the identification of a novel species of the genus Enterococcus, for which the name Enterococcus olivae sp. nov. is proposed. The type strain is IGG16.11(T) ( = CECT 8063(T) = DSM 25431(T)).

  16. Distribution of aminoglycoside resistance genes in recent clinical isolates of Enterococcus faecalis, Enterococcus faecium and Enterococcus avium.

    PubMed Central

    Kobayashi, N.; Alam, M.; Nishimoto, Y.; Urasawa, S.; Uehara, N.; Watanabe, N.

    2001-01-01

    Aminoglycoside modifying enzymes (AMEs) are major factors which confer aminoglycoside resistance on bacteria. Distribution of genes encoding seven AMEs was investigated by multiplex PCR for 279 recent clinical isolates of enterococci derived from a university hospital in Japan. The aac(6')-aph(2"), which is related to high level gentamicin resistance, was detected at higher frequency in Enterococcus faecalis (42.5%) than in Enterococcus faecium (4.3%). Almost half of E. faecalis and E. faecium isolates possessed ant(6)-Ia and aph(3')-IIIa. The profile of AME gene(s) detected most frequently in individual strains of E. faecalis was aac(6')aph(2") + ant(6)-Ia + aph(3')-IIIa, and isolates with this profile showed high level resistance to both gentamicin and streptomycin. In contrast, AME gene profiles of aac(6')-Ii+ ant(6)-Ia+aph(3')-IIIa, followed by aac(6')-Ii alone, were predominant in E. faecium. Only one AME gene profile of ant(6)-Ia+aph(3')-IIIa was found in Enterococcus avium. The ant(4')-Ia and ant(9)-Ia, which have been known to be distributed mostly among Staphylococcus aureus strains, were detected in a few enterococcal strains. An AME gene aph(2")-Ic was not detected in any isolates of the three enterococcal species. These findings indicated a variety of distribution profiles of AME genes among enterococci in our study site. PMID:11349969

  17. Presence of virulence factors in Enterococcus faecalis and Enterococcus faecium susceptible and resistant to vancomycin

    PubMed Central

    Comerlato, Carolina Baldisserotto; de Resende, Mariah Costa Carvalho; Caierão, Juliana; d'Azevedo, Pedro Alves

    2013-01-01

    Despite the increasing importance of Enterococcus as opportunistic pathogens, their virulence factors are still poorly understood. This study determines the frequency of virulence factors in clinical and commensal Enterococcus isolates from inpatients in Porto Alegre, Brazil. Fifty Enterococcus isolates were analysed and the presence of the gelE, asa1 and esp genes was determined. Gelatinase activity and biofilm formation were also tested. The clonal relationships among the isolates were evaluated using pulsed-field gel electrophoresis. The asa1, gelE and esp genes were identified in 38%, 60% and 76% of all isolates, respectively. The first two genes were more prevalent in Enterococcus faecalis than in Enterococcus faecium, as was biofilm formation, which was associated with gelE and asa1 genes, but not with the esp gene. The presence of gelE and the activity of gelatinase were not fully concordant. No relationship was observed among any virulence factors and specific subclones of E. faecalis or E. faecium resistant to vancomycin. In conclusion, E. faecalis and E. faecium isolates showed significantly different patterns of virulence determinants. Neither the source of isolation nor the clonal relationship or vancomycin resistance influenced their distribution. PMID:23903974

  18. [Investigation of Enterococcus faecalis antimicrobial resistance].

    PubMed

    Casal, M M; Cause, M; Solís, F; Rodríz, F; Casal, M

    2009-09-01

    We performed an antibiotic resistance study on Enterococcus faecalis isolated from intrahospitalary and extrahospitalary samples between january 2004 and january 2008. Three different samples were studied; urine, blood and wound swabs, considering a strain per patient. We included in the study a global amount of 3,641 Enterococcus faecalis isolations from clinical samples received at Hospital Universitario Reina Sofía microbiology service in Córdoba (Spain). We employed semiautomatic system WIDER I (Soria Melguizo) for identification and sensibility testing. We considered sensibility and resistance criteria recommended by MENSURA group. We found a sensitivity rate of 98.04% to betalactamics.The highest resistance rates were obtained with aminoglycosides, between 33.82% and 48.01%. Linezolid and Vancomycin sensitivity was 100%. It seems that vancomycin resistance is not a worrying issue today, but it should be controlled.

  19. Rapid detection of Enterococcus spp. direct from blood culture bottles using Enterococcus QuickFISH method: a multicenter investigation.

    PubMed

    Deck, Melissa K; Anderson, Erica S; Buckner, Rebecca J; Colasante, Georgia; Davis, Thomas E; Coull, James M; Crystal, Benjamin; Latta, Phyllis Della; Fuchs, Martin; Fuller, Deanna; Harris, Will; Hazen, Kevin; Klimas, Lisa L; Lindao, Daniel; Meltzer, Michelle C; Morgan, Margie; Shepard, Janeen; Stevens, Sharon; Wu, Fann; Fiandaca, Mark J

    2014-04-01

    The performance of a diagnostic method for detection and identification of Enterococcus spp. directly from positive blood culture was evaluated in a clinical study. The method, Enterococcus QuickFISH BC, is a second-generation peptide nucleic acid (PNA) fluorescence in situ hybridization (FISH) test, which uses a simplified, faster assay procedure. The test uses fluorescently labeled PNA probes targeting 16S rRNA to differentiate Enterococcus faecalis from other Enterococcus spp. by the color of the cellular fluorescence. Three hundred fifty-six routine blood culture samples were tested; only 2 discordant results were recorded. The sensitivities for detection of Enterococcus faecalis and non-faecalis Enterococcus were 100% (106/106) and 97.0% (65/67), respectively, and the combined specificity of the assay was 100%. The combined positive and negative predictive values of the assay were 100% (171/171) and 98.9% (185/187), respectively.

  20. Association between Enterococcus bacteraemia and death in neutropenic patients with haematological malignancies.

    PubMed

    Todeschini, Giuseppe; Tecchio, Cristina; Borghero, Carlo; D'Emilio, Anna; Pegoraro, Enrico; de Lalla, Fausto; Benedetti, Paolo; Spolaore, Paolo; Pellizzer, Giampietro

    2006-10-01

    Fatality rates and prognostic factors for mortality due to Enterococcus spp. bacteraemia have not yet been fully defined in the setting of neutropenic patients affected with haematological malignancies. We have performed a retrospective, multi-centre cohort study on 98 episodes of Enterococcus bacteraemia occurring in patients hospitalised from January 1984 to December 2001 at the oncohaematology units in two tertiary-care hospitals (Verona Hospital and Vicenza Hospital, in north-east Italy). E. faecalis was isolated in 52 cases (53%), E. faecium in 39 (39.8%), E. avium in four, E. durans in one, and untyped Enterococcus spp. in two other cases; vancomycin resistance was detected in 15 (15.3%) isolates. A global mortality rate of 41.8% (41/98 cases) was revealed; Enterococcus spp. bacteraemia was associated with a fatal outcome in 29/98 cases (29.5%). The following variables were independently associated with an increased risk of death by multivariate analysis of survival: age > or =50 years (OR 3.74; 95% CI 1.35-10.32), pneumonia (OR 4.70; 95% CI 1.67-13.20), and shock (OR 13.7; 95% CI 1.23-152.43), while the initial phase of haematological disease (responsive to chemotherapy) appeared to be protective (OR 0.23; 95% CI 0.008-0.64, P level 0.005); however, pneumonia alone (OR 7.2, 95% CI 2.52-20.88) was independently associated with fatal outcome by multivariate analysis for death related to enterococcal bacteraemia. In our experience, the poor outcome proper to enterococcal bacteraemia appears to be directly related to underlying disease, patient's age, presence of pneumonia and shock; in contrast, severe neutropaenia, antibiotic resistance, and species of Enterococcus do not appear to affect the fatality rate significantly.

  1. The Enterococcus hirae Mur-2 enzyme displays N-acetylglucosaminidase activity

    PubMed Central

    Eckert, Catherine; Magnet, Sophie; Mesnage, Stéphane

    2007-01-01

    Enterococcus hirae produces two autolytic enzymes named Mur-1 and Mur-2, both previously described as N-acetylmuramidases. We used tandem mass spectrometry to show that Mur-2 in fact displays N-acetylglucosaminidase activity. This result reveals that Mur-2 and its counterparts studied to date, which are members of glycosyl hydrolase family 73 from the CAZy (Carbohydrate-Active enZyme) database, display the same catalytic activity. PMID:17258207

  2. Phenotypic and molecular antibiotic resistance profile of Enterococcus faecalis and Enterococcus faecium isolated from different traditional fermented foods.

    PubMed

    Sánchez Valenzuela, Antonio; Lavilla Lerma, Leyre; Benomar, Nabil; Gálvez, Antonio; Pérez Pulido, Rubén; Abriouel, Hikmate

    2013-02-01

    A collection of 55 enterococci (41 Enterococcus faecium and 14 E. faecalis strains) isolated from various traditional fermented foodstuffs of both animal and vegetable origins, and water was evaluated for resistance against 15 antibiotics. Lower incidence of resistance was observed with gentamicin, ampicillin, penicillin and teicoplanin. However, a high incidence of antibiotic resistance was detected for rifampicin (12 out of 14 of isolates), ciprofloxacin (9/14), and quinupristin/dalfopristin (8/14) in E. faecalis strains. Enterococcus faecium isolates were resistant to rifampicin (25/41), ciprofloxacin (23/41), erythromycin (18/41), levofloxacin (16/41), and nitrofurantoin (15/41). One Enterococcus faecalis and two E. faecium strains were resistant to vancomycin (MIC>16 μg/mL). Among 55 isolates, 27 (19 E. faecium and eight E. faecalis) were resistant to at least three antibiotics. High level of multidrug resistance to clinically important antibiotics was detected in E. faecalis strains (57% of E. faecalis versus 46% of E. faecium), which showed resistance to six to seven antibiotics, especially those isolated from foods of animal origin. So, it is necessary to re-evaluate the use of therapeutic antibiotics in stock farms at both regional and international levels due to the high number of multiple resistant (MR) bacteria. Fifty-six MR E. faecalis and E. faecium strains selected from this and previous studies (Valenzuela et al., 2008, 2010) were screened by polymerase chain reaction for antibiotic resistance genes, revealing the presence of tet(L), tet(M), ermB, cat, efrA, efrB, mphA, or msrA/B genes. The ABC Multidrug Efflux Pump EfrAB was detected in 96% of E. faecalis strains and also in 13% of E. faecium strains; this is the first report describing EfrAB in this enterococcal species. The efflux pump-associated msrA/B gene was detected in 66.66% of E. faecium strains, but not in E. faecalis strains.

  3. Pheromone-inducible conjugation in Enterococcus faecalis

    PubMed Central

    Kozlowicz, Briana K.; Dworkin, Martin; Dunny, Gary M.

    2009-01-01

    Pheromone-inducible transfer of the plasmid pCF10 in Enterococcus faecalis is regulated using a complicated network of proteins and RNAs. The plasmid itself has been assembled from parts garnered from a variety of sources, and many aspects of the system resemble a biological kluge. Recently several new functions of various pCF10 gene products that participate in regulation of plasmid transfer have been identified. The results indicate that selective pressures controlling the evolution of the plasmid have produced a highly complex regulatory network with multiple biological functions that may serve well as a model for the evolution of biological complexity. PMID:16503196

  4. Production of tyramine by Enterococcus faecalis strains in water-boiled salted duck.

    PubMed

    Liu, Fang; Du, Lihui; Xu, Weiyan; Wang, Daoying; Zhang, Muhan; Zhu, Yongzhi; Xu, Weimin

    2013-05-01

    The potential to produce biogenic amines was investigated with 15 Lactococcus lactis and 15 Enterococcus faecalis strains isolated from water-boiled salted duck. The production of biogenic amines from the isolated strains grown in de Man Rogosa Sharpe broth containing precursor amino acids was determined by thin-layer chromatography and high-performance liquid chromatography. None of the L. lactis strains produced any biogenic amines, whereas 12 strains of E. faecalis produced tyramine and b -phenylethylamine. PCR assays were used to detect the presence of tyrosine decarboxylase genes in all of the isolated strains. Only the 12 biogenic amine-producing Enterococcus strains had a 924-bp fragment characteristic for the tyrosine decarboxylase gene. The comparison of the amplified partial tyrDC gene sequences of the 12 positive Enterococcus strains revealed 99% similarity within the same species. The tyramine production of the sterilized water-boiled salted duck inoculated with E. faecalis R612Z1 increased significantly during storage. This study reveals that the isolated E. faecalis strains can produce tyramine and β-phenylethylamine in the medium; however, they can only produce tyramine in water-boiled salted duck.

  5. Enterococcus bulliens sp. nov., a novel lactic acid bacterium isolated from camel milk.

    PubMed

    Kadri, Zaina; Spitaels, Freek; Cnockaert, Margo; Praet, Jessy; El Farricha, Omar; Swings, Jean; Vandamme, Peter

    2015-11-01

    Four lactic acid bacteria isolates obtained from fresh dromedary camel milk produced in Dakhla, a city in southern Morocco, were characterised in order to determine their taxonomic position. The four isolates had highly similar MALDI-TOF MS and RAPD fingerprints and identical 16S rRNA gene sequences. Comparative sequence analysis revealed that the 16S rRNA gene sequence of the four isolates was most similar to that of Enterococcus sulfureus ATCC 49903(T) and Enterococcus italicus DSM 15952(T) (99.33 and 98.59% similarity, respectively). However, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes revealed that the taxon represented by strain LMG 28766(T) was well separated from E. sulfureus LMG 13084(T) and E. italicus LMG 22039(T), which was further confirmed by DNA-DNA hybridization values that were clearly below the species demarcation threshold. The novel taxon was easily differentiated from its nearest neighbour species through sequence analysis of protein encoding genes, MALDI-TOF mass spectrometry and multiple biochemical tests, but had a similar percentage G+C content of about 39%. We therefore propose to formally classify these isolates as Enterococcus bulliens sp. nov., with LMG 28766(T) (=CCMM B1177(T)) as the type strain.

  6. Antimicrobial resistance profile of Enterococcus spp isolated from food in Southern Brazil

    PubMed Central

    Riboldi, Gustavo Pelicioli; Frazzon, Jeverson; d’Azevedo, Pedro Alves; Frazzon, Ana Paula Guedes

    2009-01-01

    Fifty-six Enterococcus spp. strains were isolated from foods in Southern Brazil, confirmed by PCR and classified as Enterococcus faecalis (27), Enterococcus faecium (23) and Enterococcus spp (6). Antimicrobial susceptibility tests showed resistance phenotypes to a range of antibiotics widely administrated in humans such as gentamycin, streptomycin, ampicillin and vancomycin. PMID:24031330

  7. Transferable Multiresistance Plasmids Carrying cfr in Enterococcus spp. from Swine and Farm Environment

    PubMed Central

    Liu, Yang; Wang, Yang; Schwarz, Stefan; Li, Yun; Shen, Zhangqi; Zhang, Qijing; Wu, Congming

    2013-01-01

    Seventy-seven porcine Enterococcus isolates with florfenicol MICs of ≥16 μg of were/ml screened for the presence of the multiresistance gene cfr, its location on plasmids, and its genetic environment. Three isolates—Enterococcus thailandicus 3-38 (from a porcine rectal swab collected at a pig farm), Enterococcus thailandicus W3, and Enterococcus faecalis W9-2 (the latter two from sewage at a different farm), carried the cfr gene. The SmaI pulsed-field gel electrophoresis patterns of the three isolates differed distinctly. In addition, E. faecalis W9-2 was assigned to a new multilocus sequence type ST469. Mating experiments and Southern blot analysis indicated that cfr is located on conjugative plasmids pW3 (∼75 kb) from E. thailandicus W3, p3-38 (∼72 kb) from E. thailandicus 3-38, and pW9-2 (∼55 kb) from E. faecalis W9-2; these plasmids differed in their sizes, additional resistance genes, and the analysis of the segments encompassing the cfr gene. Sequence analysis revealed that all plasmids harbored a 4,447-bp central region, in which cfr was bracketed by two copies of the novel insertion sequence ISEnfa4 located in the same orientation. The sequences flanking the central regions of these plasmids, including the partial tra gene regions and a ω-ε-ζ toxin-antitoxin module, exhibited >95% nucleotide sequence identity to the conjugative plasmid pAMβ1 from E. faecalis. Conjugative plasmids carrying cfr appear to play an important role in the dissemination and maintenance of the multiresistance gene cfr among enterococcal isolates and possibly other species of Gram-positive bacteria. PMID:23070165

  8. Transferable multiresistance plasmids carrying cfr in Enterococcus spp. from swine and farm environment.

    PubMed

    Liu, Yang; Wang, Yang; Schwarz, Stefan; Li, Yun; Shen, Zhangqi; Zhang, Qijing; Wu, Congming; Shen, Jianzhong

    2013-01-01

    Seventy-seven porcine Enterococcus isolates with florfenicol MICs of ≥16 μg of were/ml screened for the presence of the multiresistance gene cfr, its location on plasmids, and its genetic environment. Three isolates-Enterococcus thailandicus 3-38 (from a porcine rectal swab collected at a pig farm), Enterococcus thailandicus W3, and Enterococcus faecalis W9-2 (the latter two from sewage at a different farm), carried the cfr gene. The SmaI pulsed-field gel electrophoresis patterns of the three isolates differed distinctly. In addition, E. faecalis W9-2 was assigned to a new multilocus sequence type ST469. Mating experiments and Southern blot analysis indicated that cfr is located on conjugative plasmids pW3 (∼75 kb) from E. thailandicus W3, p3-38 (∼72 kb) from E. thailandicus 3-38, and pW9-2 (∼55 kb) from E. faecalis W9-2; these plasmids differed in their sizes, additional resistance genes, and the analysis of the segments encompassing the cfr gene. Sequence analysis revealed that all plasmids harbored a 4,447-bp central region, in which cfr was bracketed by two copies of the novel insertion sequence ISEnfa4 located in the same orientation. The sequences flanking the central regions of these plasmids, including the partial tra gene regions and a ω-ε-ζ toxin-antitoxin module, exhibited >95% nucleotide sequence identity to the conjugative plasmid pAMβ1 from E. faecalis. Conjugative plasmids carrying cfr appear to play an important role in the dissemination and maintenance of the multiresistance gene cfr among enterococcal isolates and possibly other species of Gram-positive bacteria.

  9. Detection of a cfr(B) Variant in German Enterococcus faecium Clinical Isolates and the Impact on Linezolid Resistance in Enterococcus spp.

    PubMed Central

    Fleige, Carola; Klare, Ingo; Fiedler, Stefan; Mischnik, Alexander; Mutters, Nico T.; Dingle, Kate E.; Werner, Guido

    2016-01-01

    The National Reference Centre for Staphylococci and Enterococci in Germany has received an increasing number of clinical linezolid-resistant E. faecium isolates in recent years. Five isolates harbored a cfr(B) variant gene locus the product of which is capable of conferring linezolid resistance. The cfr(B)-like methyltransferase gene was also detected in Clostridium difficile. Antimicrobial susceptibility was determined for cfr(B)-positive and linezolid-resistant E. faecium isolates and two isogenic C. difficile strains. All strains were subjected to whole genome sequencing and analyzed with respect to mutations in the 23S rDNA, rplC, rplD and rplV genes and integration sites of the cfr(B) variant locus. To evaluate methyltransferase function, the cfr(B) variant of Enterococcus and Clostridium was expressed in both E. coli and Enterococcus spp. Ribosomal target site mutations were detected in E. faecium strains but absent in clostridia. Sequencing revealed 99.9% identity between cfr(B) of Enterococcus and cfr of Clostridium. The methyltransferase gene is encoded by transposon Tn6218 which was present in C. difficile Ox3196, truncated in some E. faecium and absent in C. difficile Ox3206. The latter finding explains the lack of linezolid and chloramphenicol resistance in C. difficile Ox3206 and demonstrates for the first time a direct correlation of elevated linezolid MICs in C. difficile upon cfr acquisition. Tn6218 insertion sites revealed novel target loci for integration, both within the bacterial chromosome and as an integral part of plasmids. Importantly, the very first plasmid-association of a cfr(B) variant was observed. Although we failed to measure cfr(B)-mediated resistance in transformed laboratory strains the occurrence of the multidrug resistance gene cfr on putatively highly mobile and/or extrachromosomal DNA in clinical isolates is worrisome with respect to dissemination of antibiotic resistances. PMID:27893790

  10. The life and times of the Enterococcus.

    PubMed Central

    Murray, B E

    1990-01-01

    Enterococci are important human pathogens that are increasingly resistant to antimicrobial agents. These organisms were previously considered part of the genus Streptococcus but have recently been reclassified into their own genus, called Enterococcus. To date, 12 species pathogenic for humans have been described, including the most common human isolates, Enterococcus faecalis and E. faecium. Enterococci cause between 5 and 15% of cases of endocarditis, which is best treated by the combination of a cell wall-active agent (such as penicillin or vancomycin, neither of which alone is usually bactericidal) and an aminoglycoside to which the organism is not highly resistant; this characteristically results in a synergistic bactericidal effect. High-level resistance (MIC, greater than or equal to 2,000 micrograms/ml) to the aminoglycoside eliminates the expected bactericidal effect, and such resistance has now been described for all aminoglycosides. Enterococci can also cause urinary tract infections; intraabdominal, pelvic, and wound infections; superinfections (particularly in patients receiving expanded-spectrum cephalosporins); and bacteremias (often together with other organisms). They are now the third most common organism seen in nosocomial infections. For most of these infections, single-drug therapy, most often with penicillin, ampicillin, or vancomycin, is adequate. Enterococci have a large number of both inherent and acquired resistance traits, including resistance to cephalosporins, clindamycin, tetracycline, and penicillinase-resistant penicillins such as oxacillin, among others. The most recent resistance traits reported are penicillinase resistance (apparently acquired from staphylococci) and vancomycin resistance, both of which can be transferred to other enterococci. It appears likely that we will soon be faced with increasing numbers of enterococci for which there is no adequate therapy. PMID:2404568

  11. Enterococcus hirae Bacteremia Associated with Acute Pancreatitis and Septic Shock

    PubMed Central

    Dicpinigaitis, Peter V.; De Aguirre, Manuel; Divito, Joseph

    2015-01-01

    Infection with Enterococcus hirae has rarely been reported in humans but is not uncommon in mammals and birds. We describe a case of Enterococcus hirae bacteremia associated with acute pancreatitis, acute cholecystitis, and septic shock responsive to antibiotic therapy and supportive critical care management. Unique aspects of this case of Enterococcus hirae bacteremia are its association with acute pancreatitis and its geographical origin. To our knowledge, this is the first report of Enterococcus hirae bacteremia occurring in a patient in the United States. Although human infection with this organism appears to be rare, all cases reported to date describe bacteremia associated with severe and life-threatening illness. Thus, physicians need to be cognizant of the clinical significance of this heretofore little recognized pathogen. PMID:26417465

  12. Enterococcus faecium small colony variant endocarditis in an immunocompetent patient

    PubMed Central

    Egido, S. Hernández; Ruiz, M. Siller; Inés Revuelta, S.; García, I. García; Bellido, J.L. Muñoz

    2015-01-01

    Small colony variants (SCV) are slow-growing subpopulations of bacteria usually associated with auxotrophism, causing persistent or recurrent infections. Enterococcus faecalis SCV have been seldom described, and only one case of Enterococcus faecium SCV has been reported, associated with sepsis in a leukaemia patient. Here we report the first case described of bacteraemia and endocarditis by SCV E. faecium in an immunocompetent patient. PMID:26862434

  13. Enterococcus Xinjiangensis sp. nov., Isolated from Yogurt of Xinjiang, China.

    PubMed

    Ren, Xiaopu; Li, Mingyang; Guo, Dongqi

    2016-09-01

    A Gram-strain-positive bacterial strain 48(T) was isolated from traditional yogurt in Xinjiang Province, China. The bacterium was characterized by a polyphasic approach, including 16S rRNA gene sequence analysis, polymerase α subunit (rpoA) gene sequence analysis, determination of DNA G+C content, DNA-DNA hybridization with the type strain of Enterococcus ratti and analysis of phenotypic features. Strain 48(T) accounted for 96.1, 95.8, 95.8, and 95.7 % with Enterococcus faecium CGMCC 1.2136(T), Enterococcus hirae ATCC 9790(T), Enterococcus durans CECT 411(T), and E. ratti ATCC 700914(T) in the 16S rRNA gene sequence similarities, respectively. The sequence of rpoA gene showed similarities of 99.0, 96.0, 96.0, and 96 % with that of E. faecium ATCC 19434(T), Enterococcus villorum LMG12287, E. hirae ATCC 9790(T), and E. durans ATCC 19432(T), respectively. Based upon of polyphasic characterization data obtained in the study, a novel species, Enterococcus xinjiangensis sp. nov., was proposed and the type strain was 48(T)(=CCTCC AB 2014041(T) = JCM 30200(T)).

  14. Bioaccumulation and distribution of selenium in Enterococcus durans.

    PubMed

    Pieniz, Simone; Andreazza, Robson; Mann, Michele Bertoni; Camargo, Flávio; Brandelli, Adriano

    2017-03-01

    Selenium is an essential nutrient for all living organisms. Under appropriate conditions lactic acid bacteria (LAB) are capable for accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. In this study, the capacity of selenium bioaccumulation by Enterococcus durans LAB18s was evaluated. The distribution of organic selenium in selenium-enriched E. durans LAB18s biomass was analyzed, and the highest percentage of organic selenium was found in the fraction of total protein, followed by the fractions of polysaccharides and nucleic acids. When the protein fraction was obtained by different extractions (water, NaCl, ethanol and NaOH) it was demonstrated that alkali-soluble protein showed the higher Selenium content. Analysis of protein fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that selenium was present in the proteins ranging from 23 to 100kDa. The cells were analyzed by scanning electron microscopy (SEM); scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). SEM, TEM and SEM/EDS showed the morphology, the selenium particles bioaccumulated into and on the cells and the amounts of selenium present into the cells, respectively. Thus, the isolate E. durans LAB18s can be a promising probiotic to be used as selenium-enriched biomass in feed trials.

  15. Structural proteins of Enterococcus faecalis bacteriophage ϕEf11

    PubMed Central

    Stevens, Roy H.; Zhang, Hongming; Hsiao, Chaiwing; Kachlany, Scott; Tinoco, Eduardo M. B.; DePew, Jessica; Fouts, Derrick E.

    2016-01-01

    ABSTRACT ϕEf11, a temperate Siphoviridae bacteriophage, was isolated by induction from a root canal isolate of Enterococcus faecalis. Sequence analysis suggested that the ϕEf11 genome included a contiguous 8 gene module whose function was related to head structure assembly and another module of 10 contiguous genes whose products were responsible for tail structure assembly. SDS-PAGE analysis of virions of a ϕEf11 derivative revealed 11 well-resolved protein bands. To unify the deduced functional gene assignments emanating from the DNA sequence data, with the structural protein analysis of the purified virus, 6 of the SDS-PAGE bands were subjected to mass spectrometry analysis. 5 of the 6 protein bands analyzed by mass spectrometry displayed identical amino acid sequences to those predicted to be specified by 4 of the ORFs identified in the ϕEf11 genome. These included: ORF8 (predicted scaffold protein), ORF10 (predicted major head protein), ORF15 (predicted major tail protein), and ORF23 (presumptive antireceptor). PMID:28090386

  16. Enterococcus faecium PBP5-S/R, the Missing Link between PBP5-S and PBP5-R

    PubMed Central

    Pietta, Ester; Montealegre, Maria Camila; Roh, Jung Hyeob; Cocconcelli, Pier Sandro

    2014-01-01

    During a study to investigate the evolution of ampicillin resistance in Enterococcus faecium, we observed that a number of E. faecium strains, mainly from the recently described subclade A2, showed PBP5 sequences in between PBP5-S and PBP5-R. These hybrid PBP5-S/R patterns reveal a progression of amino acid changes from the S form to the R form of this protein; however, these changes do not strictly correlate with changes in ampicillin MICs. PMID:25182648

  17. Enterococcus faecium PBP5-S/R, the missing link between PBP5-S and PBP5-R.

    PubMed

    Pietta, Ester; Montealegre, Maria Camila; Roh, Jung Hyeob; Cocconcelli, Pier Sandro; Murray, Barbara E

    2014-11-01

    During a study to investigate the evolution of ampicillin resistance in Enterococcus faecium, we observed that a number of E. faecium strains, mainly from the recently described subclade A2, showed PBP5 sequences in between PBP5-S and PBP5-R. These hybrid PBP5-S/R patterns reveal a progression of amino acid changes from the S form to the R form of this protein; however, these changes do not strictly correlate with changes in ampicillin MICs.

  18. Enterococcus cecorum infection in a racing pigeon.

    PubMed

    Jung, Arne; Teske, Lydia; Rautenschlein, Silke

    2014-12-01

    Until now, Enterococcus cecorum (EC) has been known as a pathogen for broilers, broiler breeders, and Pekin ducks. In the present report, we describe a fatal systemic EC infection in a young racing pigeon (Columba livia forma domestica). EC was isolated from the heart, liver, spleen, and intestine of the bird in pure culture. In the pathologic examination, the pigeon showed enteritis and an ulcerative gastritis, which may have been predisposing factors for the development of the generalized EC infection. An accumulation of gram-positive cocci in spleen tissue was found in the histopathologic examination and confirms the presence of a systemic EC infection in the pigeon. Additionally, EC was isolated from cloacal swabs of other pigeons in the same loft, but no additional pigeons were submitted for necropsy. All EC isolates tested were negative by PCR for the enterococcal virulence factors cytolysin, enterococcal surface protein, aggregation substance, hyaluronidase, and gelatinase. Therefore, the reason for the enhanced virulence of the EC isolate remains unknown. Our report confirms EC as a disease-causing agent in pigeons and presents the first data concerning the analysis of EC for virulence factors.

  19. Peptide pheromone signaling in Streptococcus and Enterococcus

    PubMed Central

    Cook, Laura C.; Federle, Michael J.

    2014-01-01

    Intercellular chemical signaling in bacteria, commonly referred to as quorum sensing (QS), relies on the production and detection of compounds known as pheromones to elicit coordinated responses among members of a community. Pheromones produced by Gram-positive bacteria are comprised of small peptides. Based on both peptide structure and sensory system architectures, Gram-positive bacterial signaling pathways may be classified into one of four groups with a defining hallmark: cyclical peptides of the Agr type, peptides that contain Gly-Gly processing motifs, sensory systems of the RNPP family, or the recently characterized Rgg-like regulatory family. The recent discovery that Rgg family members respond to peptide pheromones increases substantially the number of species in which QS is likely a key regulatory component. These pathways control a variety of fundamental behaviors including conjugation, natural competence for transformation, biofilm development, and virulence factor regulation. Overlapping QS pathways found in multiple species and pathways that utilize conserved peptide pheromones provide opportunities for interspecies communication. Here we review pheromone signaling identified in the genera Enterococcus and Streptococcus, providing examples of all four types of pathways. PMID:24118108

  20. Biofilms of Enterococcus faecalis and Enterococcus faecium isolated from the processing of ricotta and the control of these pathogens through cleaning and sanitization procedures.

    PubMed

    da Silva Fernandes, Meg; Kabuki, Dirce Yorika; Kuaye, Arnaldo Yoshiteru

    2015-05-04

    The biofilm formation of Enterococcus faecalis and Enterococcus faecium isolated from the processing of ricotta on stainless steel coupons was evaluated, and the effect of cleaning and sanitization procedures in the control of these biofilms was determined. The formation of biofilms was observed while varying the incubation temperature (7, 25 and 39°C) and time (0, 1, 2, 4, 6 and 8 days). At 7°C, the counts of E. faecalis and E. faecium were below 2 log10 CFU/cm(2). For the temperatures of 25 and 39°C, after 1 day, the counts of E. faecalis and E. faecium were 5.75 and 6.07 log10 CFU/cm(2), respectively, which is characteristic of biofilm formation. The tested sanitation procedures a) acid-anionic tensioactive cleaning, b) anionic tensioactive cleaning+sanitizer and c) acid-anionic tensioactive cleaning+sanitizer were effective in removing the biofilms, reducing the counts to levels below 0.4 log10 CFU/cm(2). The sanitizer biguanide was the least effective, and peracetic acid was the most effective. These studies revealed the ability of enterococci to form biofilms and the importance of the cleaning step and the type of sanitizer used in sanitation processes for the effective removal of biofilms.

  1. The mazEF toxin-antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis.

    PubMed

    Soheili, Sara; Ghafourian, Sobhan; Sekawi, Zamberi; Neela, Vasantha Kumari; Sadeghifard, Nourkhoda; Taherikalani, Morovat; Khosravi, Afra; Ramli, Ramliza; Hamat, Rukman Awang

    2015-01-01

    The toxin-antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains.

  2. Clinical epidemiology of vancomycin-resistant Enterococcus gallinarum and Enterococcus casseliflavus bloodstream infections.

    PubMed

    Britt, Nicholas S; Potter, Emily M

    2016-06-01

    This study aimed to evaluate the clinical outcomes of vancomycin-resistant enterococcal bloodstream infections (VRE BSI) caused by Enterococcus gallinarum or Enterococcus casseliflavus. Variables associated with treatment failure were determined and treatment options were compared. This was a national retrospective study of hospitalised Veterans Affairs patients with non-faecium, non-faecalis VRE BSI. The primary outcome was treatment failure, defined as a composite of: (i) 30-day all-cause mortality; (ii) microbiological failure; and (iii) 30-day VRE BSI recurrence. Stepwise Poisson regression was conducted to determine variables associated with treatment failure. In total, 48 patients were included, with 29 cases (60.4%) caused by E. gallinarum and 19 cases (39.6%) caused by E. casseliflavus. Among these cases, 20 (41.7%) were treated with an anti-VRE agent (linezolid or daptomycin) and 28 (58.3%) were treated with an anti-enterococcal β-lactam. Overall, 30-day mortality was 10.4% (5/48) and composite treatment failure was 39.6% (19/48). In multivariate analysis, treatment with an anti-enterococcal β-lactam was associated with increased treatment failure in comparison with anti-VRE therapy (adjusted risk ratio = 1.73, 95% confidence interval 1.06-4.97; P = 0.031). Overall, treatment with linezolid or daptomycin for vancomycin-resistant E. gallinarum or E. casseliflavus BSI resulted in improved clinical outcomes in comparison with anti-enterococcal β-lactam treatment.

  3. Molecular characterization of Rifr mutations in Enterococcus faecalis and Enterococcus faecium.

    PubMed

    Du, Xiaoxing; Hua, Xiaoting; Qu, Tingting; Jiang, Yan; Zhou, Zhihui; Yu, Yunsong

    2014-08-01

    Mutation rate is an important factor affecting the appearance and spread of acquired antibiotic resistance. The frequencies and types of enterococci mutations were determined in this study. The MICs of rifampicin in enterococci and their rifampicin-resistant mutants were determined by the Clinical and Laboratory Standards Institute (CLSI) agar dilution method. The Enterococcus faecalis isolates A15 and 18165 showed no significant differences in mutation frequencies or mutation rates. In Enterococcus faecium, the mutation frequency and mutation rate were both 6·4-fold lower than in E. faecalis. The spectrum of mutations characterized in E. faecium B42 differed significantly from that of E. faecalis. The types and rate of mutations indicated that E. faecalis had a higher potential to develop linezolid resistance. Rifampicin resistance was associated with mutations in the rpoB gene. Rifampicin MICs for the E. faecalis mutant were 2048 mg/l, but rifampicin MICs for E. faecium mutants ranged from 64 to 1024 mg/l.

  4. Description of Enterococcus canis sp. nov. from dogs and reclassification of Enterococcus porcinus Teixeira et al. 2001 as a junior synonym of Enterococcus villorum Vancanneyt et al 2001.

    PubMed

    De Graef, E M; Devriese, L A; Vancanneyt, M; Baele, M; Collins, M D; Lefebvre, K; Swings, J; Haesebrouck, F

    2003-07-01

    Strains from anal swabs and chronic otitis externa in dogs were shown to be phylogenetically related to the Enterococcus faecium species group. They shared a number of phenotypic characteristics with these species, but they could be easily differentiated by biochemical reactions. In addition, the canine strains were unusual in their nearly complete failure to grow on sodium azide-containing enterococci-selective media and in their Voges-Proskauer reactions (usually negative). By using 16S rRNA sequencing and DNA-DNA hybridization of representative strains, as well as tDNA interspacer gene PCR and SDS-PAGE of whole-cell proteins, the group of canine strains was shown to constitute a novel enterococcal species. The name Enterococcus canis sp. nov. is proposed for this species, with LMG 12316T (= CCUG 46666T) as the type strain. Concurrently, the taxonomic situation and nomenclatural position of Enterococcus porcinus were investigated. As no phenotypic or genotypic differences were found between this species and Enterococcus villorum, the name E. porcinus is considered to be a junior synonym of E. villorum.

  5. [Influence of staphylococcin T on Enterococcus sp. growth].

    PubMed

    Białucha, Agata; Kozuszko, Sylwia; Gospodarek, Eugenia; Bugalski, Roman Marian; Gierlotka, Krzysztof

    2007-01-01

    Bacteriocins are ribosomally synthesised, extracellular bacterial products. Generally, spectrum of inhibition is limited to the same or closely related species to bacteriocin producer. Staphylococcin T is produced by Staphylococcus cohnii strain. The present study concerns influence of StT to 267 Enterococcus sp. strains growth isolated between 2003 and 2006 in Department of Microbiology University Hospital of dr. A. Jurasz in Bydgoszcz. S. cohnii T antagonistic ability evaluated towards bacteries on Mueller-Hinton Agar (bio Mérieux) in aerobic conditions. After 24 and 48 hours tested enterococci suspensions were plated perpendiculary. Susceptibility to antibiotics was assessed by disc diffusion method according to the guideless of Clinical and Laboratory Standards Institute and National Reference Centre for Antimicrobial Susceptibility. Among Enterococcus sp. strains tested 7.1% were sensitive to StT. The highest percentage of sensitive enterococci isolated from wound swabs, urine, blood and pus. Enterococcus faecium strains dominated (63.2%) among enterococci sensitive to StT. Moderate inhibition degree on S. cohnii T bacteriocin action was observed in majority sensitive enterococci strains. Enterococcus sp. sensitive to StT strains were frequently multidrug resistant (68.4%). According to the study results and increasing resistance to antibiotics, StT could be an alternative agent used to treat infections caused by Enterococcus sp.

  6. Drug resistance & virulence determinants in clinical isolatesof Enterococcus species

    PubMed Central

    Fernandes, Sanal C.; Dhanashree, B.

    2013-01-01

    Background & objectives: Enterococci are the leading cause of nosocomial infections, and are thus a persisting clinical problem globally. We undertook this study to determine the virulence factors and the antibiotic resistance in Enterococcus clinical isolates. Methods: One hundred and fifty Enterococcus isolates obtained from various clinical specimens were speciated biochemically and subjected to antibiotic susceptibility testing using Kirby-Bauer disk diffusion method. Resistance to vancomycin was determined by using agar screen method. Haemolysin and gelatinase productions were detected using 5 per cent sheep blood agar and 12 per cent gelatin agar, respectively. Results: Among the 150 Enterococcus isolates, 84 (56%) were E. faecalis. 51(34%) E. faecium, and 15 (10%) were other Enterococcus spp. Haemolysin production was seen among 123 (82%) isolates while 61 (40.6%) isolates produced gelatinase. Nearly 50 per cent of the isolates showed high level aminoglycoside resistance (HLAR). A total of 13 (8.6%) isolates showed vancomycin resistance, of which 11(7.3%) had an MIC >8 μg/ml. Interpretation & conclusions: Presence of VRE was found to be low among the isolates studied. However, occurrence of VRE along with HLAR calls for regular detection of vancomycin resistance promptly and accurately to recognize VRE colonization and infection. Early detection of VRE and HLAR along with their virulence trait will help in preventing the establishment and spread of multidrug resistant Enterococcus species. PMID:23760387

  7. Enterococcus ureilyticus sp. nov. and Enterococcus rotai sp. nov., two urease-producing enterococci from the environment.

    PubMed

    Sedláček, Ivo; Holochová, Pavla; Mašlaňová, Ivana; Kosina, Marcel; Spröer, Cathrin; Bryndová, Hana; Vandamme, Peter; Rudolf, Ivo; Hubálek, Zdenek; Švec, Pavel

    2013-02-01

    A set of 25 urease-producing, yellow-pigmented enterococci was isolated from environmental sources. Phenotypic classification divided the isolates into two phena. Both phena were characterized using 16S rRNA gene sequence analysis, DNA base composition, rep-PCR fingerprinting and automated ribotyping. The obtained data distinguished the isolates from all members of the genus Enterococcus with validly published names and placed them in the Enterococcus faecalis species group. DNA-DNA hybridization experiments, pheS and rpoA sequencing and whole-cell protein electrophoresis provided conclusive evidence for the classification of each phenon as a novel species of the genus Enterococcus, for which the names Enterococcus ureilyticus sp. nov. (type strain CCM 4629(T)  = LMG 26676(T)  = CCUG 48799(T)), inhabiting water and plants, and Enterococcus rotai sp. nov. (type strain CCM 4630(T)  = LMG 26678(T)  = CCUG 61593(T)), inhabiting water, insects (mosquitoes) and plants, are proposed.

  8. A New High-Level Gentamicin Resistance Gene, aph(2")-Id, in Enterococcus spp.

    PubMed Central

    Tsai, Shane F.; Zervos, Marcus J.; Clewell, Don B.; Donabedian, Susan M.; Sahm, Daniel F.; Chow, Joseph W.

    1998-01-01

    Enterococcus casseliflavus UC73 is a clinical blood isolate with high-level resistance to gentamicin. DNA preparations from UC73 failed to hybridize with intragenic probes for aac(6′)-Ie-aph(2")-Ia and aph(2")-Ic. A 4-kb fragment from UC73 was cloned and found to confer resistance to gentamicin in Escherichia coli DH5α transformants. Nucleotide sequence analysis revealed the presence of a 906-bp open reading frame whose deduced amino acid sequence had a region with homology to the aminoglycoside-modifying enzyme APH(2")-Ic and to the C-terminal domain of the bifunctional enzyme AAC(6′)-APH(2"). The gene is designated aph(2")-Id, and its observed phosphotransferase activity is designated APH(2")-Id. A PCR-generated intragenic probe hybridized to the genomic DNA from 17 of 118 enterococcal clinical isolates (108 with high-level gentamicin resistance) from five hospitals. All 17 were vancomycin-resistant Enterococcus faecium isolates, and pulsed-field typing revealed three distinct clones. The combination of ampicillin plus either amikacin or neomycin exhibited synergistic killing against E. casseliflavus UC73. Screening and interpretation of high-level aminoglycoside resistance in enterococci may need to be modified to include detection of APH(2")-Id. PMID:9593155

  9. The effect of quercetin on genetic expression of the commensal gut microbes Bifidobacterium catenulatum, Enterococcus caccae and Ruminococcus gauvreauii.

    PubMed

    Firrman, Jenni; Liu, LinShu; Zhang, Liqing; Arango Argoty, Gustavo; Wang, Minqian; Tomasula, Peggy; Kobori, Masuko; Pontious, Sherri; Xiao, Weidong

    2016-12-01

    Quercetin is one of the most abundant polyphenols found in fruits and vegetables. The ability of the gut microbiota to metabolize quercetin has been previously documented; however, the effect that quercetin may have on commensal gut microbes remains unclear. In the present study, the effects of quercetin on the commensal gut microbes Ruminococcus gauvreauii, Bifidobacterium catenulatum and Enterococcus caccae were determined through evaluation of growth patterns and cell morphology, and analysis of genetic expression profiles between quercetin treated and non-treated groups using Single Molecule RNA sequencing via Helicos technology. Results of this study revealed that phenotypically, quercetin did not prevent growth of Ruminococcus gauvreauii, mildly suppressed growth of Bifidobacterium catenulatum, and moderately inhibited growth of Enterococcus caccae. Genetic analysis revealed that in response to quercetin, Ruminococcus gauvreauii down regulated genes responsible for protein folding, purine synthesis and metabolism. Bifidobacterium catenulatum increased expression of the ABC transport pathway and decreased metabolic pathways and cell wall synthesis. Enterococcus caccae upregulated genes responsible for energy production and metabolism, and downregulated pathways of stress response, translation and sugar transport. For the first time, the effect of quercetin on the growth and genetic expression of three different commensal gut bacteria was documented. The data provides insight into the interactions between genetic regulation and growth. This is also a unique demonstration of how RNA single molecule sequencing can be used to study the gut microbiota.

  10. Biocide and antibiotic resistance of Enterococcus faecalis and Enterococcus faecium isolated from the swine meat chain.

    PubMed

    Rizzotti, Lucia; Rossi, Franca; Torriani, Sandra

    2016-12-01

    In this study nine strains of Enterococcus faecalis and 12 strains of Enterococcus faecium, isolated from different sample types in the swine meat chain and previously characterized for the presence of antibiotic resistance genes, were examined for phenotypic tolerance to seven biocides (chlorexidine, benzalkonium chloride, triclosan, sodium hypochlorite, 2-propanol, formaldehyde and hydrogen peroxide) and resistance to nine antibiotics (ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline and chloramphenicol). Moreover, the presence of efflux system encoding genes qacA/B, qacC, qacE, qacEΔ1, emeA, and stress response genes, sigV and gsp65, involved in the tolerance to biocides, was analysed. Most strains were not tolerant to the biocides, but showed minimum inhibitory concentrations (MICs) higher than the recommended cut-off values for all the antibiotics tested, except for vancomycin and chloramphenicol. Only weak correlations, if any, were found between biocide and antibiotic resistance data. One E. faecalis strain was tolerant to triclosan and one E. faecium strain, with higher tolerance to chlorexidine than the other strains tested, was found to carry a qacA/B gene. Our results indicated that phenotypic resistance to antibiotics is very frequent in enterococcal isolates from the swine meat chain, but phenotypic tolerance to biocides is not common. On the other hand, the gene qacA/B was found for the first time in the species E. faecium, an indication of the necessity to adopt measures suitable to control the spread of biocide resistance determinants among enterococci.

  11. Enterococcus faecalis as multidrug resistance strains in clinical isolates in Imam Reza Hospital in Kermanshah, Iran.

    PubMed

    Mohammadi, F; Ghafourian, S; Mohebi, R; Taherikalani, M; Pakzad, I; Valadbeigi, H; Hatami, V; Sadeghifard, N

    2015-01-01

    The current study aimed to investigate the prevalence of vancomycin-resistant Enterococcus in E. faecalis and E. faecium and antimicrobial susceptibility patterns, then dominant genes responsible for vancomycin resistance were determined. For this propose, 180 clinical isolates of Enterococcus were subjected for identification and antibiotic susceptibility assay. Then, the gene responsible vancomycin resistant strains were determined. The results demonstrated the E. faecalis as a dominant Enterococcus. Resistance to erythromycin was dominant and multidrug resistance strains observed in E. faecalis. vanA was responsible for vancomycin resistance. In conclusion, a high rate of resistance to antibiotics in Enterococcus is clearly problematic, and a novel strategy is needed to decrease resistance in Enterococcus.

  12. Multicenter clinical evaluation of VRESelect agar for identification of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium.

    PubMed

    Anderson, Neil W; Buchan, Blake W; Young, Carol L; Newton, Duane W; Brenke, Connie; Lapsley, Linda; Granato, Paul A; Ledeboer, Nathan A

    2013-08-01

    A chromogenic medium for identification of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium, VRESelect, was compared to bile esculin azide agar with 6 μg/ml vancomycin (BEAV) for the isolation of vancomycin-resistant enterococci (VRE) from stool specimens. At 24 to 28 h, VRESelect demonstrated 98.7% (confidence interval [CI], 96.1 to 99.7%) sensitivity and 99.0% (CI, 98.0 to 99.6%) specificity versus 85.1% (CI, 79.8 to 89.5%) and 90.1% (CI, 79.8 to 89.5%) sensitivity and specificity, respectively, for BEAV.

  13. Genome Sequence of Enterococcus faecalis Strain CG_E.

    PubMed

    Gabris, Christina; Poehlein, Anja; Bengelsdorf, Frank R; Daniel, Rolf; Dürre, Peter

    2017-01-12

    Enterococcus faecalis CG_E is a Gram-positive, lactic acid-producing coccus. The draft genome of E. faecalis strain CG_E comprises 2,969,881 bp and exhibits a G+C content of 37.34%. The genome encodes 2,848 predicted protein-encoding and 97 RNA genes.

  14. Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry.

    PubMed

    Stępień-Pyśniak, Dagmara; Marek, Agnieszka; Banach, Tomasz; Adaszek, Łukasz; Pyzik, Ewelina; Wilczyński, Jarosław; Winiarczyk, Stanisław

    2016-06-01

    The aim of this study was to evaluate the frequency of occurrence of bacteria of the genus Enterococcus in poultry, to identify them by means of matrixassisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF MS), and to analyse the antimicrobial susceptibility of the isolated strains to the drugs most frequently used in poultry. The material for the bacteriological tests was obtained mainly from the heart (97%) of the birds investigated. Of a total of 2,970 samples tested, 911 (30.7%) tested positive for Enterococcus spp. Enterococci were detected in broilers (88.1%), laying hens (5.3%), turkeys (3.9%), breeding hens (2.2%), and geese (0.4%). The most commonly identified species were Enterococcus (E.) faecalis (74.7%), E. faecium (10.1%), E. gallinarum (5.5%), E. hirae (4.6%), and E. cecorum (4.1%). The most frequent resistance properties were resistance to sulphamethoxazole/trimethoprim (88%), tylosin (71.4%), enrofloxacin (69.4%), doxycycline (67.3%), and lincomycin/spectinomycin (56.1%). Only one vancomycin-resistant Enterococcus, E. cecorum from a broiler, was found.

  15. Survival of Escherichia coli and Enterococcus in Stream Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E. coli and Enterococcus indicate fecal contamination and are used for monitoring of lakes, streams, and rivers. Transport of bacteria from manured or pastured lands can result in large bacterial loads from both small and large runoff events and the persistence of bacteria following these loadings i...

  16. Enterococcus saccharolyticus subsp. taiwanensis subsp. nov., isolated from broccoli.

    PubMed

    Chen, Yi-sheng; Lin, Yu-hsuan; Pan, Shwu-fen; Ji, Si-hua; Chang, Yu-chung; Yu, Chi-rong; Liou, Min-shiuan; Wu, Hui-chung; Otoguro, Misa; Yanagida, Fujitoshi; Liao, Chen-chung; Chiu, Chi-ming; Huang, Bi-qiang

    2013-12-01

    A coccal strain isolated from fresh broccoli was initially identified as Enterococcus saccharolyticus; however, molecular identification and phenotypic traits did not support this identification. DNA-DNA hybridization with the type strain of E. saccharolyticus (76.4 % relatedness), DNA G+C content (35.7 mol%), phylogenetic analysis based on 16S rRNA, pheS and rpoA gene sequences, rep-PCR fingerprinting and profiles of cellular fatty acids, whole-cell proteins and enzyme activities, together with carbohydrate metabolism characteristics, indicated that this strain is distinct and represents a novel subspecies, for which the name Enterococcus saccharolyticus subsp. taiwanensis subsp. nov. is proposed. The type strain is 812(T) ( = NBRC 109476(T) = BCRC 80575(T)). Furthermore, we present an emended description of Enterococcus saccharolyticus and proposal of Enterococcus saccharolyticus subsp. saccharolyticus subsp. nov. (type strain ATCC 43076(T) = CCUG 27643(T) = CCUG 33311(T) = CIP 103246(T) = DSM 20726(T) = JCM 8734(T) = LMG 11427(T) = NBRC 100493(T) = NCIMB 702594(T)).

  17. An antimicrobial peptidoglycan hydrolase for treating Enterococcus faecalis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enterococcus faecalis is an intestinal bacteria species that can become an opportunistic pathogen in humans and farm animals with antibiotic resistant strains becoming increasingly common. In farm animals, strong antimicrobials, such as Vancomycin, should not be used due to the risk of propagation ...

  18. Genome Sequence of Enterococcus faecalis Strain CG_E

    PubMed Central

    Gabris, Christina; Daniel, Rolf

    2017-01-01

    ABSTRACT Enterococcus faecalis CG_E is a Gram-positive, lactic acid-producing coccus. The draft genome of E. faecalis strain CG_E comprises 2,969,881 bp and exhibits a G+C content of 37.34%. The genome encodes 2,848 predicted protein-encoding and 97 RNA genes. PMID:28082508

  19. Aerobic condition increases carotenoid production associated with oxidative stress tolerance in Enterococcus gilvus.

    PubMed

    Hagi, Tatsuro; Kobayashi, Miho; Nomura, Masaru

    2014-01-01

    Although it is known that a part of lactic acid bacteria can produce carotenoid, little is known about the regulation of carotenoid production. The objective of this study was to determine whether aerobic growth condition influences carotenoid production in carotenoid-producing Enterococcus gilvus. Enterococcus gilvus was grown under aerobic and anaerobic conditions. Its growth was slower under aerobic than under anaerobic conditions. The decrease in pH levels and production of lactic acid were also lower under aerobic than under anaerobic conditions. In contrast, the amount of carotenoid pigments produced by E. gilvus was significantly higher under aerobic than under anaerobic conditions. Further, real-time quantitative reverse transcription PCR revealed that the expression level of carotenoid biosynthesis genes crtN and crtM when E. gilvus was grown under aerobic conditions was 2.55-5.86-fold higher than when it was grown under anaerobic conditions. Moreover, after exposure to 16- and 32-mM H2O2, the survival rate of E. gilvus grown under aerobic conditions was 61.5- and 72.5-fold higher, respectively, than when it was grown under anaerobic conditions. Aerobic growth conditions significantly induced carotenoid production and the expression of carotenoid biosynthesis genes in E. gilvus, resulting in increased oxidative stress tolerance.

  20. High Frequency of Vancomycin-Resistant Enterococcus Faecalis in an Iranian Referral Children Medical Hospital

    PubMed Central

    POURAKBARI, Babak; AGHDAM, Mojtaba Kamali; MAHMOUDI, Shima; ASHTIANI, Mohammad Taghi Haghi; SABOUNI, Farah; MOVAHEDI, Zahra; ALYARI, Amir Esmael; SADEGHI, Reihane Hosseinpour; MAMISHI, Setareh

    2012-01-01

    ABSTRACT Background: Enterococci have emerged in recent years as important nosocomial pathogens. Although most enterococcal human infections are caused by Enterococcus faecalis, studies on vancomycin resistance are usually limited to Enterococcus faecium isolates and a little is known about E. faecalis. Therefore we undertook this study to obtain information about the prevalence of vancomycin -resistant E. faecalis (VREF) and genes responsible for resistance. Material and methods: Ninety-one E. faecalis isolates of different patients admitted at Children's Medical Center from August 2009 to June 2010 were included in this cross-sectional study. Antimicrobial testing was performed by Kirby-Bauer disk diffusion method according to Clinical Laboratories Standards Institute (CLSI). Results: Among all isolates, 15 (16%) were identified as VR E. faecalis. PCR analysis revealed that all VREF isolates were positive for the vanA gene. Conclusion: The present study reports the highest range of VREF in Iran. The increased frequency of VREF, as seen with rapid rise in the number of VanA isolates should be considered in infection control practices. PMID:23400108

  1. Outbreak of vancomycin-susceptible Enterococcus faecium containing the wild-type vanA gene.

    PubMed

    Szakacs, Tom A; Kalan, Lindsay; McConnell, Michael J; Eshaghi, Alireza; Shahinas, Dea; McGeer, Allison; Wright, Gerry D; Low, Donald E; Patel, Samir N

    2014-05-01

    Accurate detection of vancomycin-resistant enterococci (VRE) is essential in preventing transmission in health care settings. Chromogenic media are widely used for screening VRE because of fast turnaround times (TAT) and high sensitivity. We report an outbreak of Enterococcus faecium bearing vanA yet susceptible to vancomycin (vancomycin-variable Enterococcus [VVE]). Between October 2009 to March 2011, clinical and screening specimens (n=14,747) were screened for VRE using VRE-selective medium and/or PCR. VVE isolates were genotyped to determine relatedness. Plasmids from these isolates were characterized by sequencing. Overall, 52 VVE isolates were identified, comprising 15% of all VRE isolates identified. Isolates demonstrated growth on Brilliance VRE agar (Oxoid) at 24 h of incubation but did not grow on brain heart infusion agar with 6 μg/ml vancomycin (Oxoid) or bile esculin azide agar with 6 μg/ml vancomycin (Oxoid) and were susceptible to vancomycin. Genotyping of 20 randomly selected VVE isolates revealed that 15/20 were identical, while 5 were highly related. PCR of the VVE transposon confirmed the presence of vanHAXY gene cluster; however, vanS (sensor) and vanR (regulator) genes were absent. The outbreak was controlled through routine infection control measures. We report an emergence of a fit strain of E. faecium containing vanA yet susceptible to vancomycin. Whether this new strain represents VRE has yet to be determined; however, unique testing procedures are required for reliable identification of VVE.

  2. Characterization of veterinary hospital-associated isolates of Enterococcus species in Korea.

    PubMed

    Chung, Yeon Soo; Kwon, Ka Hee; Shin, Sook; Kim, Jae Hong; Park, Yong Ho; Yoon, Jang Won

    2014-03-28

    Possible cross-transmission of hospital-associated enterococci between human patients, medical staff, and hospital environments has been extensively studied. However, limited information is available for veterinary hospital-associated Enterococcus isolates. This study investigated the possibility of cross-transmission of antibiotic-resistant enterococci between dog patients, their owners, veterinary staff, and hospital environments. Swab samples (n =46 5) were obtained from five veterinary hospitals in Seoul, Korea, during 2011. Forty-three Enterococcus strains were isolated, representing seven enterococcal species. E. faecalis and E. faecium were the most dominant species (16 isolates each, 37.2%). Although slight differences in the antibiotic resistance profiles were observed between the phenotypic and the genotypic data, our antibiogram analysis demonstrated high prevalence of the multiple drug-resistant (MDR) isolates of E. faecalis (10/16 isolates, 62.5%) and E. faecium (12/16 isolates, 75.0%). Pulsed-field gel electrophoretic comparison of the MDR isolates revealed three different clonal sets of E. faecalis and a single set of E. faecium, which were isolated from different sample groups or dog patients at the same or two separate veterinary hospitals. These results imply a strong possibility of cross-transmission of the antibiotic-resistant enterococcal species between animal patients, owners, veterinary staff, and hospital environments.

  3. Antimicrobial resistance and virulence profiles of Enterococcus spp. isolated from horses in korea.

    PubMed

    Kim, Dae Ho; Chung, Yeon Soo; Park, Young Kyung; Yang, Soo-Jin; Lim, Suk Kyung; Park, Yong Ho; Park, Kun Taek

    2016-10-01

    Antimicrobial-resistant (AR) enterococci have emerged as leading nosocomial pathogens. Transmission of AR Enterococci from animals to humans has been demonstrated. However, there is limited information on the transmission of enterococci from horses to humans. To address this issue, we characterized 260 enterococci isolated from horse-associated samples in Korea in 2013 based on their AR profiles and virulence traits. AR profiling revealed an average ratio of AR enterococci of 23.8%. Seven isolates (2.7%) were multidrug-resistant Enterococcus faecalis. Most tetracycline-resistant enterococci harbored either tetM or tetL or both genes; genes conferring resistance to other antimicrobials were detected at low rates. Biofilm formation and gelatinase activity were observed in 51.1% and 47.7% of isolates, respectively; most were E. faecalis harboring the gelE gene. Evidence of transmission of AR enterococci between horses and their environments was provided by pulsed-field gel electrophoresis, and highlights the risk of AR enterococcus transmission to horse riders and handlers through close contact.

  4. Investigation of mechanism and molecular epidemiology of linezolid-resistant Enterococcus faecalis in China.

    PubMed

    Wang, Lipeng; He, Yunyan; Xia, Yun; Wang, Huijuan; Liang, Shumei

    2014-08-01

    Enterococcus is a major cause of important nosocomial infections. Linezolid, the first member of an entirely new class of antibiotics (oxazolidinones), is effective against serious infections caused by Enterococcus. However, resistance to linezolid has been discovered throughout the world rapidly. From 2011 to 2013, nine linezolid-resistant E. faecalis isolates were collected and the possible mechanisms of linezolid resistance, including mutations in domain V of 23S rRNA genes and in ribosomal proteins L3 and L4, and the multiresistance gene cfr, were investigated. Furthermore, an epidemiological survey of the nine linezolid-resistant E. faecalis isolates was performed by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and DiversiLab. The three methods were compared to evaluate their merits and demerits, respectively. We failed to find the resistance mechanisms that have been revealed in recent years by PCR and sequencing analysis in the linezolid-resistant E. faecalis. Epidemiological investigation suggested that a small-scale outbreak of linezolid-resistant E. faecalis emerged in neurosurgery ICU from March to May of 2013. DiversiLab was a reliable typing tool and a suitable alternative to PFGE because it was as discriminatory as PFGE and better than MLST.

  5. Effect of Nanosilver Gel, Chlorhexidine Gluconate, and Camphorated Phenol on Enterococcus faecalis Biofilm.

    PubMed

    Bo, Dong; Kayombo, Cecilia Marcellino

    2014-01-01

    Aim. To assess the effectiveness of nanosilver gel (NSG) in comparison to chlorhexidine gluconate (CHX) and camphorated phenol (CP) against Enterococcus faecalis (E.f) biofilm. Methods and Materials. Two tests were done, methyl thiazolyl tetrazolium (MTT) assay and confocal laser scanning microscopy (CLSM) analysis, to determine the effectiveness of NSG, CHX, and CP on E.f biofilm. Polystyrene microtiter 96- and 6-well plates were used for MTT and CLSM, respectively. Nanosilver gel was in three concentrations (0.05%, 0.1%, and 0.2%), chlorhexidine gluconate used was 2%, and camphorated phenol and normal saline were as control. Analysis was done using one-way ANOVA; the post hoc test was run for multiple comparisons. The level of statistical significance was set at P < 0.05. Results. One-way ANOVA showed significant differences among groups (0.05% NSG and CP, 0.1% NSG and CP, 0.2% NSG and CP, 0.1% NSG and 2% CHX, 0.2% and NSG and 2% CHX) (P < 0.001) and also showed significant difference between groups (P < 0.001), f-ratio 87.823. A post hoc Tukey's test revealed no significant difference between chlorhexidine gluconate and 0.05% nanosilver gel (P > 0.05). Conclusions. 0.1% and 0.2% nanosilver gel is more effective on Enterococcus faecalis biofilm as compared to chlorhexidine gluconate and camphorated phenol.

  6. Comparison between automated system and PCR-based method for identification and antimicrobial susceptibility profile of clinical Enterococcus spp.

    PubMed

    Furlaneto-Maia, Luciana; Rocha, Kátia Real; Siqueira, Vera Lúcia Dias; Furlaneto, Márcia Cristina

    2014-01-01

    Enterococci are increasingly responsible for nosocomial infections worldwide. This study was undertaken to compare the identification and susceptibility profile using an automated MicrosScan system, PCR-based assay and disk diffusion assay of Enterococcus spp. We evaluated 30 clinical isolates of Enterococcus spp. Isolates were identified by MicrosScan system and PCR-based assay. The detection of antibiotic resistance genes (vancomycin, gentamicin, tetracycline and erythromycin) was also determined by PCR. Antimicrobial susceptibilities to vancomycin (30 µg), gentamicin (120 µg), tetracycline (30 µg) and erythromycin (15 µg) were tested by the automated system and disk diffusion method, and were interpreted according to the criteria recommended in CLSI guidelines. Concerning Enterococcus identification the general agreement between data obtained by the PCR method and by the automatic system was 90.0% (27/30). For all isolates of E. faecium and E. faecalis we observed 100% agreement. Resistance frequencies were higher in E. faecium than E. faecalis. The resistance rates obtained were higher for erythromycin (86.7%), vancomycin (80.0%), tetracycline (43.35) and gentamicin (33.3%). The correlation between disk diffusion and automation revealed an agreement for the majority of the antibiotics with category agreement rates of > 80%. The PCR-based assay, the van(A) gene was detected in 100% of vancomycin resistant enterococci. This assay is simple to conduct and reliable in the identification of clinically relevant enterococci. The data obtained reinforced the need for an improvement of the automated system to identify some enterococci.

  7. Enterococcus faecalis prophage dynamics and contributions to pathogenic traits.

    PubMed

    Matos, Renata C; Lapaque, Nicolas; Rigottier-Gois, Lionel; Debarbieux, Laurent; Meylheuc, Thierry; Gonzalez-Zorn, Bruno; Repoila, Francis; Lopes, Maria de Fatima; Serror, Pascale

    2013-06-01

    Polylysogeny is frequently considered to be the result of an adaptive evolutionary process in which prophages confer fitness and/or virulence factors, thus making them important for evolution of both bacterial populations and infectious diseases. The Enterococcus faecalis V583 isolate belongs to the high-risk clonal complex 2 that is particularly well adapted to the hospital environment. Its genome carries 7 prophage-like elements (V583-pp1 to -pp7), one of which is ubiquitous in the species. In this study, we investigated the activity of the V583 prophages and their contribution to E. faecalis biological traits. We systematically analyzed the ability of each prophage to excise from the bacterial chromosome, to replicate and to package its DNA. We also created a set of E. faecalis isogenic strains that lack from one to all six non-ubiquitous prophages by mimicking natural excision. Our work reveals that prophages of E. faecalis V583 excise from the bacterial chromosome in the presence of a fluoroquinolone, and are able to produce active phage progeny. Intricate interactions between V583 prophages were also unveiled: i) pp7, coined EfCIV583 for E. faecalis chromosomal island of V583, hijacks capsids from helper phage 1, leading to the formation of distinct virions, and ii) pp1, pp3 and pp5 inhibit excision of pp4 and pp6. The hijacking exerted by EfCIV583 on helper phage 1 capsids is the first example of molecular piracy in Gram positive bacteria other than staphylococci. Furthermore, prophages encoding platelet-binding-like proteins were found to be involved in adhesion to human platelets, considered as a first step towards the development of infective endocarditis. Our findings reveal not only a role of E. faecalis V583 prophages in pathogenicity, but also provide an explanation for the correlation between antibiotic usage and E. faecalis success as a nosocomial pathogen, as fluoriquinolone may provoke release of prophages and promote gene dissemination among

  8. Eight-year Surveillance of Antimicrobial Resistance among Enterococcus Spp. Isolated in the First Bethune Hospital

    NASA Astrophysics Data System (ADS)

    Xu, Jiancheng; Wang, Liqiang; Wang, Kai; Zhou, Qi

    This study was to investigate the antimicrobial resistance of Enterococcus spp. isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 1446 strains of Enterococcus spp. were collected from urine 640 (44.3%), sputum 315 (21.8%), secretions and pus 265 (18.3%) during the past 8 years. The rates of high-level aminoglycoside resistance in Enterococcus faecalis and Enterococcus faecium were 57.4%∼75.9% and 69.0%∼93.8% during the past 8 years, respectively. No Enterococcus spp. was resistant to vancomycin. The antimicrobial resistance of Enterococcus spp. had increased in recent 8 years. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

  9. Structural studies of the Enterococcus faecalis SufU [Fe-S] cluster protein

    PubMed Central

    Riboldi, Gustavo P; Verli, Hugo; Frazzon, Jeverson

    2009-01-01

    Background Iron-sulfur clusters are ubiquitous and evolutionarily ancient inorganic prosthetic groups, the biosynthesis of which depends on complex protein machineries. Three distinct assembly systems involved in the maturation of cellular Fe-S proteins have been determined, designated the NIF, ISC and SUF systems. Although well described in several organisms, these machineries are poorly understood in Gram-positive bacteria. Within the Firmicutes phylum, the Enterococcus spp. genus have recently assumed importance in clinical microbiology being considered as emerging pathogens for humans, wherein Enterococcus faecalis represents the major species associated with nosocomial infections. The aim of this study was to carry out a phylogenetic analysis in Enterococcus faecalis V583 and a structural and conformational characterisation of it SufU protein. Results BLAST searches of the Enterococcus genome revealed a series of genes with sequence similarity to the Escherichia coli SUF machinery of [Fe-S] cluster biosynthesis, namely sufB, sufC, sufD and SufS. In addition, the E. coli IscU ortholog SufU was found to be the scaffold protein of Enterococcus spp., containing all features considered essential for its biological activity, including conserved amino acid residues involved in substrate and/or co-factor binding (Cys50,76,138 and Asp52) and, phylogenetic analyses showed a close relationship with orthologues from other Gram-positive bacteria. Molecular dynamics for structural determinations and molecular modeling using E. faecalis SufU primary sequence protein over the PDB:1su0 crystallographic model from Streptococcus pyogenes were carried out with a subsequent 50 ns molecular dynamic trajectory. This presented a stable model, showing secondary structure modifications near the active site and conserved cysteine residues. Molecular modeling using Haemophilus influenzae IscU primary sequence over the PDB:1su0 crystal followed by a MD trajectory was performed to analyse

  10. Enterococcus spp. in a single blood culture: bacteremia or contamination?

    PubMed

    Khatib, R; Labalo, V; Sharma, M; Johnson, L B; Riederer, K

    2017-03-01

    We retrospectively evaluated adult cases with Enterococcus spp. in 1 blood culture (BC) (1/1/2010-12/31/2015; n=294) and stratified them into bacteremia or contamination. Contamination frequency was similar in community versus hospital-onset, E. faecalis versus E. faecium, and number of BC drawn per day. Contamination predictors were vancomycin-resistance, ampicillin-resistance, commensal organism copresence, and nonurinary/abdominal sources.

  11. Probiotic properties and adsorption of Enterococcus faecalis PSCT3-7 to vermiculite

    PubMed Central

    Kim, Jin-Yoon; Awji, Elias Gebru; Park, Na-Hye; Park, Ji-Yong; Kim, Jong-Choon; Lee, Sam-Pin

    2017-01-01

    The probiotic properties of Enterococcus (E.) faecalis PSCT3-7, a new strain isolated from the intestines of pigs fed dietary fiber containing 50% sawdust, were investigated. E. faecalis PSCT3-7 tolerated a pH range of 3 to 8 and 0.3% bile salts, and it inhibited the growth of Salmonella Typhimurium in a concentration-dependent manner. In addition, E. faecalis showed resistance to several antibacterial agents. Vermiculite, a nutrient and microbial carrier, increased the bile tolerance of the strain. Scanning electron microscope images revealed good adsorption of E. faecalis PSCT3-7 onto vermiculite. E. faecalis PSCT3-7 represents a potential probiotic candidate to administer with vermiculite to swine. PMID:27456777

  12. Probiotic properties and adsorption of Enterococcus faecalis PSCT3-7 to vermiculite.

    PubMed

    Kim, Jin-Yoon; Awji, Elias Gebru; Park, Na-Hye; Park, Ji-Yong; Kim, Jong-Choon; Lee, Sam-Pin; Suh, Joo-Won; Park, Seung-Chun

    2017-03-30

    The probiotic properties of Enterococcus (E.) faecalis PSCT3-7, a new strain isolated from the intestines of pigs fed dietary fiber containing 50% sawdust, were investigated. E. faecalis PSCT3-7 tolerated a pH range of 3 to 8 and 0.3% bile salts, and it inhibited the growth of Salmonella Typhimurium in a concentration-dependent manner. In addition, E. faecalis showed resistance to several antibacterial agents. Vermiculite, a nutrient and microbial carrier, increased the bile tolerance of the strain. Scanning electron microscope images revealed good adsorption of E. faecalis PSCT3-7 onto vermiculite. E. faecalis PSCT3-7 represents a potential probiotic candidate to administer with vermiculite to swine.

  13. Antimicrobial resistance in Enterococcus strains isolated from healthy domestic dogs.

    PubMed

    Bertelloni, Fabrizio; Salvadori, Claudia; Lotti, Giulia; Cerri, Domenico; Ebani, Valentina Virginia

    2016-12-15

    Enterococci are opportunistic bacteria that cause severe infections in animals and humans, capable to acquire, express, and transfer antimicrobial resistance. Susceptibility to 21 antimicrobial agents was tested by the disk diffusion method in 222 Enterococcus spp. strains isolated from the fecal samples of 287 healthy domestic dogs. Vancomycin and ampicillin minimum inhibitory concentrations (MICs) and high-level aminoglycoside resistance (HLAR) tests were also performed. Isolates showed resistance mainly to streptomycin (88.7%), neomycin (80.6%), and tetracycline (69.4%). Forty-two (18.9%) isolates showed an HLAR to streptomycin and 15 (6.7%) to gentamicin. Vancomycin and ampicillin MIC values showed 1 and 18 resistant strains, respectively. One hundred and thirty-six (61.2%) strains were classified as multidrug resistant and six (2.7%) strains as possibly extensively drug-resistant bacteria. Enterococcus faecium and Enterococcus faecalis were the most prevalent antimicrobial resistant species. Companion animals, which often live in close contact with their owners and share the same environment, represent a serious source of enterococci resistant to several antibiotics; for this reason, they may be a hazard for public health by providing a conduit for the entrance of resistance genes into the community.

  14. Enterococcus xiangfangensis sp. nov., isolated from Chinese pickle.

    PubMed

    Li, Chun Yan; Tian, Fen; Zhao, Ya Dong; Gu, Chun Tao

    2014-03-01

    A Gram-stain-positive bacterial strain, 11097(T), was isolated from traditional pickle in Heilongjiang Province, China. The bacterium was characterized using a polyphasic approach, including 16S rRNA gene sequence analysis, phenylalanyl-tRNA synthase (pheS) gene sequence analysis, RNA polymerase α subunit (rpoA) gene sequence analysis, fatty acid methyl ester (FAME) analysis, determination of DNA G+C content, DNA-DNA hybridization and an analysis of phenotypic features. Strain 11097(T) was phylogenetically related to Enterococcus devriesei, E. pseudoavium, E. viikkiensis, E. avium, E. malodoratus, E. gilvus and E. raffinosus. Strain 11097(T) had 99.1-99.9% 16S rRNA gene sequence similarities, 78.2-83.2% pheS gene sequence similarities and 93.8-96.6% rpoA gene sequence similarities with type strains of phylogenetically related species. Based upon polyphasic characterization data obtained in the present study, a novel species of the genus Enterococcus, Enterococcus xiangfangensis sp. nov., is proposed with the type strain 11097(T) ( = LMG 27495(T) = NCIMB 14834(T)).

  15. A new chromogenic agar medium, chromID VRE, to screen for vancomycin-resistant Enterococcus faecium and Enterococcus faecalis.

    PubMed

    Ledeboer, Nathan A; Tibbetts, Robert J; Dunne, William M

    2007-12-01

    We compared the performance of a chromogenic agar medium chromID VRE (bioMérieux, Marcy-l'Etoile, France) designed to recover and identify vancomycin-resistant enterococci (VRE) from clinical specimens with bile esculin azide vancomycin (BEAV) agar. For this study, 120 stool specimens were plated on chromID VRE and BEAV and examined after 24 and 48 h. At 24 h, the sensitivity and specificity were as follows: BEAV, 90.2% and 73%, respectively; chromID VRE, 86.3% and 100.0%, respectively. Furthermore, we determined that the sensitivity and specificity of chromID VRE for Enterococcus faecium were 85.4% and 100%, respectively, and for Enterococcus faecalis, 90% and 100%, respectively. We conclude that chromID VRE provides an equivalent sensitivity for the recovery of VRE from stool specimens, with improved specificity, and the added advantage of providing differentiation between vancomycin-resistant E. faecium and E. faecalis.

  16. Relationship between biofilm formation, the enterococcal surface protein (Esp) and gelatinase in clinical isolates of Enterococcus faecalis and Enterococcus faecium.

    PubMed

    Di Rosa, Roberta; Creti, Roberta; Venditti, Mario; D'Amelio, Raffaele; Arciola, Carla R; Montanaro, Lucio; Baldassarri, Lucilla

    2006-03-01

    One-hundred and twenty-eight enterococcal isolates were examined for their ability to form biofilm in relation to the presence of the gene encoding the enterococcal surface protein (esp), production of gelatinase and to the source of isolation. Neither esp nor gelatinase seemed to be required for biofilm formation: both Enterococcus faecalis and Enterococcus faecium did not show a correlation between the presence of either esp or the production of gelatinase and biofilm formation. However, in E. faecium while esp was found in isolates from either source, the presence of both esp and biofilm together was only found in strains from clinical settings, suggesting that there exists a synergy between these factors which serves as an advantage for the process of infection.

  17. Escherichia coli and Enterococcus faecalis are able to incorporate and enhance a pre-formed Gardnerella vaginalis biofilm.

    PubMed

    Castro, Joana; Machado, Daniela; Cerca, Nuno

    2016-04-01

    Gardnerella vaginalis is the most frequent microorganism found in bacterial vaginosis (BV), while Escherichia coli and Enterococcus faecalis are amongst the most frequent pathogens found in urinary tract infections (UTIs). This study aimed to evaluate possible interactions between UTIs pathogens and G. vaginalis using an in vitro dual-species biofilm model. Our results showed that dual-species biofilms reached significantly higher bacterial concentration than monospecies biofilms. Moreover, visualization of dual-populations species in the biofilms, using the epifluorescence microscopy, revealed that all of the urogenital pathogens coexisted with G. vaginalis. In conclusion, our work demonstrates that uropathogens can incorporate into mature BV biofilms.

  18. Enterococcus rivorum sp. nov., from water of pristine brooks.

    PubMed

    Niemi, R Maarit; Ollinkangas, Tuula; Paulin, Lars; Svec, Pavel; Vandamme, Peter; Karkman, Antti; Kosina, Marcel; Lindström, Kristina

    2012-09-01

    A significant number of Enterococcus strains from pristine waters of two brooks in Finland formed a distinct cluster on the basis of whole-cell protein fingerprinting by one-dimensional SDS-PAGE. The strains shared the following characteristics. Cells were ovoid, Gram-positive-staining and non-spore-forming, appearing singly or in pairs or chains. They were facultatively anaerobic and catalase-negative. Growth in broth containing 6.5 % NaCl or at 45 °C was weak or absent. Production of D antigen was variable. The strains tolerated 60 °C for 30 min, 40 % bile and tellurite, hydrolysed aesculin strongly and gelatin weakly, produced no acid from hippurate and did not reduce it, grew weakly at 10 °C, showed a strong reaction for the Voges-Proskauer test and produced acid from methyl α-d-glucoside, mannitol, sorbitol and sucrose, with weak or no production of acid from methyl α-d-mannoside, l-arabinose, gluconate and l-xylose. Several of the strains were selected for identification on the basis of sequencing of almost the whole 16S rRNA gene and partial atpA and pheS genes and of (GTG)(5)-PCR fingerprints. Partial atpA and pheS gene sequencing was also performed for those type strains of Enterococcus species without available sequences in the database. The pristine brook isolates formed a novel species, for which the name Enterococcus rivorum sp. nov. (type strain S299(T) = HAMBI 3055(T) = LMG 25899(T) = CCM 7986(T)) is proposed. On the basis of 16S rRNA gene sequence similarity, E. rivorum sp. nov. is related to the Enterococcus faecalis genogoup. It is distinguished from described Enterococcus species on the basis of 16S rRNA, atpA and pheS gene sequences and whole-cell protein and (GTG)(5)-PCR fingerprints. It is most closely related to E. faecalis, but DNA-DNA hybridization confirms it to represent a novel species.

  19. Two novel species Enterococcus lemanii sp. nov. and Enterococcus eurekensis sp. nov., isolated from a swine-manure storage pit.

    PubMed

    Cotta, Michael A; Whitehead, Terence R; Falsen, Enevold; Moore, Edward; Lawson, Paul A

    2013-01-01

    A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular genetic methods was performed on six strains of unknown Gram-positive, nonspore-forming, facultative anaerobic coccus-shaped bacteria isolated from a swine-manure storage pit. On the basis of the 16S rRNA, RNA polymerase α-subunit (rpoA) and 60 kDa chaperonin (cpn60) gene sequence analyses, it was shown that all the isolates were enterococci but formed two separate lines of descent. Pairwise 16S rRNA gene sequence comparisons demonstrated that the two novel organisms were most closely related to each other (97.9 %) and to Enterococcus aquimarinus (97.8 %). Both organisms contained major amounts of C(16:0), C(16:1) ω7c, C(16:1) ω7c, and C(18:1) ω7c/12t/9t as the major cellular fatty acids. Based on biochemical, chemotaxonomic and phylogenetic evidence, the names Enterococcus lemanii sp. nov. (type strain PC32(T) = CCUG 61260(T) = NRRL B-59661(T)) PPC27A = CCUG 61369; PPC38 = CCUG 61261 [corrected] and Enterococcus eurekensis sp. nov. (type strain PC4B(T) = CCUG 61259(T) = NRRL B-59662(T)) PPC15 = CCUG 61368; PPC107 = CCUG 61372 [corrected] are proposed for these hitherto undescribed species.

  20. Systems biology approach for mapping the response of human urothelial cells to infection by Enterococcus faecalis

    PubMed Central

    Dozmorov, Mikhail G; Kyker, Kimberly D; Saban, Ricardo; Shankar, Nathan; Baghdayan, Arto S; Centola, Michael B; Hurst, Robert E

    2007-01-01

    Background To better understand the response of urinary epithelial (urothelial) cells to Enterococcus faecalis, a uropathogen that exhibits resistance to multiple antibiotics, a genome-wide scan of gene expression was obtained as a time series from urothelial cells growing as a layered 3-dimensional culture similar to normal urothelium. We herein describe a novel means of analysis that is based on deconvolution of gene variability into technical and biological components. Results Analysis of the expression of 21,521 genes from 30 minutes to 10 hours post infection, showed 9553 genes were expressed 3 standard deviations (SD) above the system zero-point noise in at least 1 time point. The asymmetric distribution of relative variances of the expressed genes was deconvoluted into technical variation (with a 6.5% relative SD) and biological variation components (>3 SD above the mode technical variability). These 1409 hypervariable (HV) genes encapsulated the effect of infection on gene expression. Pathway analysis of the HV genes revealed an orchestrated response to infection in which early events included initiation of immune response, cytoskeletal rearrangement and cell signaling followed at the end by apoptosis and shutting down cell metabolism. The number of poorly annotated genes in the earliest time points suggests heretofore unknown processes likely also are involved. Conclusion Enterococcus infection produced an orchestrated response by the host cells involving several pathways and transcription factors that potentially drive these pathways. The early time points potentially identify novel targets for enhancing the host response. These approaches combine rigorous statistical principles with a biological context and are readily applied by biologists. PMID:18047719

  1. Genetic analysis of a novel plasmid encoded durancin locus in Enterococcus durans 41D

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enterococcus durans is commonly found in the intestinal tract in humans and animals and several strains are known to produce bacteriocins. Durancin GL, a novel bacteriocin of Enterococcus durans 41D with antilisterial activity was isolated from artisanal cheese samples and its genetic determinants ...

  2. Comparison of the effect of monolaurin on the growth and survival of Enterococcus and Salmonella

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of monolaurin, a glyceride ester derivative of lauric acid, on the growth of Enterococcus sp. and Salmonella sp. was determined. Salmonella is considered one of the main pathogens in poultry industry, and Enterococcus is an important indicator of fecal contamination and an important cause...

  3. Bioprosthetic Aortic Valve Endocarditis in Association with Enterococcus durans

    PubMed Central

    Di Gioacchino, Lorena; Balestrini, Fabrizio

    2016-01-01

    Enterococci are common organisms associated with endocarditis, but infection by Enterococcus durans is very rare. To our knowledge, only 3 cases have been reported in the medical literature, and all 3 have involved native valves. Here we publish the first reported case (to our knowledge) of E. durans endocarditis in association with a bioprosthetic aortic valve. After the organism and its antibiotic susceptibility were identified, the 74-year-old male patient was treated successfully with teicoplanin and gentamicin, over a course of 6 weeks. PMID:27127436

  4. Erythromycin- and copper-resistant Enterococcus hirae from marine sediment and co-transfer of erm(B) and tcrB to human Enterococcus faecalis.

    PubMed

    Pasquaroli, Sonia; Di Cesare, Andrea; Vignaroli, Carla; Conti, Giulia; Citterio, Barbara; Biavasco, Francesca

    2014-09-01

    An erythromycin-, copper- and cadmium-resistant isolate of Enterococcus hirae from marine sediment was shown to harbor the plasmid pRE25 and to co-transfer erm(B) and tcrB to Enterococcus faecalis JH2-2. These data highlight the scope for antibiotic resistance selection by the marine environment through heavy metals and its possible involvement in antibiotic-resistant enterococcal infections.

  5. Antibiotic Susceptibilities of Enterococcus Species Isolated from Hospital and Domestic Wastewater Effluents in Alice, Eastern Cape Province of South Africa

    PubMed Central

    Iweriebor, Benson Chuks; Gaqavu, Sisipho; Obi, Larry Chikwelu; Nwodo, Uchechukwu U.; Okoh, Anthony I.

    2015-01-01

    Background: Antimicrobial resistance in microorganisms are on the increase worldwide and are responsible for substantial cases of therapeutic failures. Resistance of species of Enterococcus to antibiotics is linked to their ability to acquire and disseminate antimicrobial resistance determinants in nature, and wastewater treatment plants (WWTPs) are considered to be one of the main reservoirs of such antibiotic resistant bacteria. We therefore determined the antimicrobial resistance and virulence profiles of some common Enterococcus spp that are known to be associated with human infections that were recovered from hospital wastewater and final effluent of the receiving wastewater treatment plant in Alice, Eastern Cape. Methods: Wastewater samples were simultaneously collected from two sites (Victoria hospital and final effluents of a municipal WWTP) in Alice at about one to two weeks interval during the months of July and August 2014. Samples were screened for the isolation of enterococci using standard microbiological methods. The isolates were profiled molecularly after targeted generic identification and speciation for the presence of virulence and antibiotic resistance genes. Results: Out of 66 presumptive isolates, 62 were confirmed to belong to the Enterococcus genusof which 30 were identified to be E. faecalis and 15 E. durans. The remaining isolates were not identified by the primers used in the screening procedure. Out of the six virulence genes that were targeted only three of them; ace, efaA, and gelE were detected. There was a very high phenotypic multiple resistance among the isolates and these were confirmed by genetic analyses. Conclusions: Analyses of the results obtained indicated that hospital wastewater may be one of the sources of antibiotic resistant bacteria to the receiving WWTP. Also, findings revealed that the final effluent discharged into the environment was contaminated with multi-resistant enterococci species thus posing a health hazard

  6. In situ molecular diagnosis and histopathological characterization of enteroadherent Enterococcus hirae infection in pre-weaning-age kittens.

    PubMed

    Nicklas, Jodi L; Moisan, Peter; Stone, Maria R; Gookin, Jody L

    2010-08-01

    The bacterial causes of diarrhea can be frustrating to identify, and it is likely that many remain undiagnosed. The pathogenic potential of certain bacteria becomes less ambiguous when they are observed to intimately associate with intestinal epithelial cells. In the present study we sought to retrospectively characterize the clinical, in situ molecular, and histopathological features of enteroadherent bacteria in seven unrelated kittens that were presumptively diagnosed with enteropathogenic Escherichia coli (EPEC) on the basis of postmortem light microscopic and, in some cases, microbiological examination. Characterization of the enteroadherent bacteria in each case was performed by Gram staining, in situ hybridization using fluorescence-labeled oligonucleotide probes, PCR amplification of species-specific gene sequences, and ultrastructural imaging applied to formalin-fixed paraffin-embedded sections of intestinal tissue. In only two kittens was EPEC infection confirmed. In the remaining five kittens, enteroadherent bacteria were identified as Enterococcus spp. The enterococci were further identified as Enterococcus hirae on the basis of PCR amplification of DNA extracted from the formalin-fixed, paraffin-embedded tissue and amplified by using species-specific primers. Transmission electron microscopy of representative lesions from E. coli- and Enterococcus spp.-infected kittens revealed coccobacilli adherent to intestinal epithelial cells without effacement of microvilli or cup-and-pedestal formation. Enterococci were not observed, nor were DNA sequences amplified from intestinal tissue obtained from age-matched kittens euthanized for reasons unrelated to intestinal disease. These studies suggest that E. hirae may be a common cause of enteroadherent bacterial infection in pre-weaning-age kittens and should be considered in the differential diagnosis of bacterial disease in this population.

  7. Genetic variability of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis isolates from humans, chickens, and pigs in Malaysia.

    PubMed

    Getachew, Yitbarek; Hassan, Latiffah; Zakaria, Zunita; Abdul Aziz, Saleha

    2013-08-01

    Vancomycin-resistant enterococci (VRE) have been reported to be present in humans, chickens, and pigs in Malaysia. In the present study, representative samples of VRE isolated from these populations were examined for similarities and differences by using the multilocus sequence typing (MLST) method. Housekeeping genes of Enterococcus faecium (n = 14) and Enterococcus faecalis (n = 11) isolates were sequenced and analyzed using the MLST databases eBURST and goeBURST. We found five sequence types (STs) of E. faecium and six STs of E. faecalis existing in Malaysia. Enterococcus faecium isolates belonging to ST203, ST17, ST55, ST79, and ST29 were identified, and E. faecium ST203 was the most common among humans. The MLST profiles of E. faecium from humans in this study were similar to the globally reported nosocomial-related strain lineage belonging to clonal complex 17 (CC17). Isolates from chickens and pigs have few similarities to those from humans, except for one isolate from a chicken, which was identified as ST203. E. faecalis isolates were more diverse and were identified as ST4, ST6, ST87, ST108, ST274, and ST244, which were grouped as specific to the three hosts. E. faecalis, belonging to the high-risk CC2 and CC87, were detected among isolates from humans. In conclusion, even though one isolate from a chicken was found clonal to that of humans, the MLST analysis of E. faecium and E. faecalis supports the findings of others who suggest VRE to be predominantly host specific and that clinically important strains are found mainly among humans. The infrequent detection of a human VRE clone in a chicken may in fact suggest a reverse transmission of VRE from humans to animals.

  8. Inhibition of Listeria monocytogenes by Enterococcus mundtii isolated from soil.

    PubMed

    Bigwood, T; Hudson, J A; Cooney, J; McIntyre, L; Billington, C; Heinemann, J A; Wall, F

    2012-12-01

    Two bacterial isolates with inhibitory activity against Listeria monocytogenes and Enterococcus faecalis were obtained from soil. Genotypic and phenotypic characterization identified them as Enterococcus mundtii, a species whose ability to compete with L. monocytogenes is relatively unexplored compared to other members of the genus. The thermal stability of the inhibitory factor and its sensitivity to proteolytic enzymes indicate that it is most likely a bacteriocin. Both isolates grew at comparable rates to L. monocytogenes at 5 °C and 10 °C in vitro. One isolate killed L. monocytogenes when it reached concentrations of 10(6)-10(8) CFU ml(-1). Minimum inocula of 10(6) and 10(5) CFU ml(-1) of E. mundtii were required to reduce and maintain L. monocytogenes concentrations beneath the level of detection at 5 °C and 10 °C, respectively. In situ experiments at 5 °C showed that E. mundtii inhibited the growth of L. monocytogenes on vacuum-packed cold smoked salmon during its four week shelf life. E. mundtii could, therefore, control the growth of L. monocytogenes at low temperatures, indicating a potential application in controlling this pathogen in chilled foods. To control growth of Listeria, the concentration of E. mundtii needs to be high, but it is possible that a purified bacteriocin could be used to achieve the same effect.

  9. Eradication of Enterococcus faecalis Biofilms on Human Dentin

    PubMed Central

    Rosen, Eyal; Tsesis, Igor; Elbahary, Shlomo; Storzi, Nimrod; Kolodkin-Gal, Ilana

    2016-01-01

    Objectives: This work assesses different methods to interfere with Enterococcus faecalis biofilms formed on human dentin slabs. Methods: First, methods are presented that select for small molecule inhibitors of biofilm targets using multi-well polystyrene biofilm plates. Next, we establish methodologies to study and interfere with biofilm formation on a medically relevant model, whereby biofilms are grown on human root dentin slabs. Results: Non-conventional D-amino acid (D-Leucine) can efficiently disperse biofilms formed on dentin slabs without disturbing planktonic growth. Cation chelators interfere with biofilm formation on dentin slabs and polystyrene surfaces, and modestly impact planktonic growth. Strikingly, sodium hypochlorite, the treatment conventionally used to decontaminate infected root canal systems, was extremely toxic to planktonic bacteria, but did not eradicate biofilm cells. Instead, it induced a viable but non-culturable state in biofilm cells when grown on dentin slabs. Conclusion: Sodium hypochlorite may contribute to bacterial persistence. A combination of the methods described here can greatly contribute to the development of biofilm inhibitors and therapies to treat Enterococcus faecalis infections formed in the root canal system. PMID:28082955

  10. Characterization of different food-isolated Enterococcus strains by MALDI-TOF mass fingerprinting.

    PubMed

    Quintela-Baluja, Marcos; Böhme, Karola; Fernández-No, Inmaculada C; Morandi, Stefano; Alnakip, Mohammed E; Caamaño-Antelo, Sonia; Barros-Velázquez, Jorge; Calo-Mata, Pilar

    2013-08-01

    Enterococcus is a controversial genus due to its great variability; this genus includes pathogenic strains, spoilage strains, and apparently safe strains including some probiotic strains. Previous studies focused on the characterization of strains of Enterococcus spp. involved in nosocomial infections. However, little research has been conducted on Enterococcus strains in foodstuffs. In the present work, 36 strains of different species of Enterococcus have been characterized by means of MALDI-TOF MS, resulting in highly specific mass spectral fingerprints. Characteristic peak masses common to certain bacterial species of Enterococcus have been identified. Thus, a peak at m/z 4426 ± 1 was assigned as a genus-specific biomarker. In addition, phyloproteomic relationships based on the mass spectral data were compared to the results of a phylogenetic analysis based on the 16S rRNA gene sequence. A better grouping at the species level was observed in the phyloproteomic tree, especially for the Enterococcus faecium group. Presumably, the assortment of some strains or ecotypes could be related to their ecological niche specialization. The approach described in this study leads the way toward the rapid and specific identification of different strains and species of Enterococcus in food based on molecular protein markers, aiming at the early detection of pathogenic strains and strains implicated in food poisoning or food spoilage.

  11. Characterization of vancomycin-resistant Enterococcus isolates from broilers in Selangor, Malaysia.

    PubMed

    Getachew, Y M; Hassan, L; Zakaria, Z; Saleha, A A; Kamaruddin, M I; Che Zalina, M Z

    2009-12-01

    Vancomycin-resistant Enterococcus (VRE) is an emerging nosocomial pathogen in humans. The use of antibiotics in human therapy and in the production of food animals has been incriminated in the emergence of this organism. The present study describes the distribution of VRE species, the vancomycin-resistant genes detected, the vancomycin resistance pattern observed, and the genetic diversity of the isolates found in live broiler chickens in Malaysia. Overall 140 VRE were isolated with species comprising Enterococcus faecalis (48%), Enterococcus faecium (25.7%), Enterococcus gallinarum (12.1%), Enterococcus casseliflavus (1.4%) and other Enterococcus species (12.8%). Vancomycin resistance gene vanA and intrinsic genes vanC1 and vanC2/3 were detected in the study population. VanA was detected in 15 (63.9%) of E. faecium, 23 (22.4%) of E. faecalis and in 3 (17.6%) E. gallinarum isolates. E-test was conducted on randomly selected 41 of the isolates and the minimum inhibition concentration (MIC) of vancomycin for five (11.9%) of tested isolates is more than 256 μg/ml. Genotypic analysis using random amplified polymorphic DNA (RAPD) showed genetic diversity within the Enterococcus species.

  12. Differences in Antibiotic Resistance Patterns of Enterococcus faecalis and Enterococcus faecium Strains Isolated from Farm and Pet Animals

    PubMed Central

    Butaye, Patrick; Devriese, Luc A.; Haesebrouck, Freddy

    2001-01-01

    The prevalence of acquired resistance in 146 Enterococcus faecium and 166 Enterococcus faecalis strains from farm and pet animals, isolated in 1998 and 1999 in Belgium, against antibiotics used for growth promotion and for therapy was determined. Acquired resistance against flavomycin and monensin, two antibiotics used solely for growth promotion, was not detected. Avoparcin (glycopeptide) resistance was found sporadically in E. faecium only. Avilamycin resistance was almost exclusively seen in strains from farm animals. Resistance rates were higher in E. faecium strains from broiler chickens than in strains from other animal groups with tylosin and virginiamycin and in E. faecalis as well as in E. faecium strains with narasin and bacitracin. Resistance against ampicillin was mainly found among E. faecium strains from pets and was absent in E. faecalis. Tetracycline resistance occurred most often in strains from farm animals, while enrofloxacin resistance, only found in E. faecalis, occurred equally among strains from all origins. Resistance against gentamicin was very rare in broiler strains, whereas resistance rates were high in strains from other origins. It can be concluded that resistance against antibiotics used solely for growth promotion was more prevalent in E. faecium strains than in E. faecalis strains. With few exceptions, resistance against the different categories of antibiotics was more prevalent in strains from farm animals than in those from pets. PMID:11302798

  13. Differences in antibiotic resistance patterns of Enterococcus faecalis and Enterococcus faecium strains isolated from farm and pet animals.

    PubMed

    Butaye, P; Devriese, L A; Haesebrouck, F

    2001-05-01

    The prevalence of acquired resistance in 146 Enterococcus faecium and 166 Enterococcus faecalis strains from farm and pet animals, isolated in 1998 and 1999 in Belgium, against antibiotics used for growth promotion and for therapy was determined. Acquired resistance against flavomycin and monensin, two antibiotics used solely for growth promotion, was not detected. Avoparcin (glycopeptide) resistance was found sporadically in E. faecium only. Avilamycin resistance was almost exclusively seen in strains from farm animals. Resistance rates were higher in E. faecium strains from broiler chickens than in strains from other animal groups with tylosin and virginiamycin and in E. faecalis as well as in E. faecium strains with narasin and bacitracin. Resistance against ampicillin was mainly found among E. faecium strains from pets and was absent in E. faecalis. Tetracycline resistance occurred most often in strains from farm animals, while enrofloxacin resistance, only found in E. faecalis, occurred equally among strains from all origins. Resistance against gentamicin was very rare in broiler strains, whereas resistance rates were high in strains from other origins. It can be concluded that resistance against antibiotics used solely for growth promotion was more prevalent in E. faecium strains than in E. faecalis strains. With few exceptions, resistance against the different categories of antibiotics was more prevalent in strains from farm animals than in those from pets.

  14. Enterococcus species composition determined by capillary electrophoresis of the groESL gene spacer region DNA.

    PubMed

    Yasuda, M; Paar, J; Doolittle, M; Brochi, J; Pancorbo, O C; Tang, R J; Stoner, R E; Shiaris, M P

    2010-07-01

    Marine recreational beaches are monitored for fecal contamination by Enterococcus spp. (ENT) counts. Although different ENT species in the environment tend to thrive in and originate from distinct hosts, the current monitoring method does not differentiate among species. Time-consuming isolation-based species identification precludes routine analysis of environmental ENT communities. Therefore, an isolation-independent DNA fingerprinting method was developed to characterize environmental ENT communities using DNA length polymorphism of the spacer region between the groES and groEL genes common to most ENT species. Capillary electrophoresis resulted in distinct peak sizes of PCR products that carried polymorphic groESL spacers (300-335 bp in length) among 8 different ENT species (Enterococcus avium, Enterococcus gallinarum, Enterococcus casseliflavus, Enterococcus mundtii, Enterococcus hirae, Enterococcus faecium, Enterococcus durans, and Enterococcus faecalis). Distortions in true species ratios observed in electropherograms were caused by PCR biases arising in a mixed ENT community DNA template. E. faecalis was overestimated and E. avium and E. faecium were underestimated compared to the original species ratios in the mixed community. The PCR product bias was constant between species, so good approximation of the species ratio in ENT communities is possible. In environmental samples, a high percentage of E. faecalis (96%) together with high total ENT counts were observed in samples collected from a sewer line and from several sites in a storm drain system where sewage leaks were suspected. In contrast, samples with <400 CFU 100 ml-1 ENT were either dominated by E. mundtii or had 4 or more ENT species. The latter ENT community profiles are considered to be signatures of enterococci rarely associated with animals with low or of non-fecal origin.

  15. Diversity of Antibiotic Resistance Genes in Enterococcus Strains Isolated from Ready-to-Eat Meat Products.

    PubMed

    Chajęcka-Wierzchowska, Wioleta; Zadernowska, Anna; Łaniewska-Trokenheim, Łucja

    2016-10-25

    The objective of the study was to answer the question of whether the ready-to-eat meat products can pose indirect hazard for consumer health serving as reservoir of Enterococcus strains harboring tetracyclines, aminoglycosides, and macrolides resistance genes. A total of 390 samples of ready-to-eat meat products were investigated. Enterococcus strains were found in 74.1% of the samples. A total of 302 strains were classified as: Enterococcus faecalis (48.7%), Enterococcus faecium (39.7%), Enterococcus casseliflavus (4.3%), Enterococcus durans (3.0%), Enterococcus hirae (2.6%), and other Enterococcus spp. (1.7%). A high percentage of isolates were resistant to streptomycin high level (45%) followed by erythromycin (42.7%), fosfomycin (27.2%), rifampicin (19.2%), tetracycline (36.4%), tigecycline (19.9%). The ant(6')-Ia gene was the most frequently found gene (79.6%). Among the other genes that encode aminoglycosides-modifying enzymes, the highest portion of the strains had the aac(6')-Ie-aph(2'')-Ia (18.5%) and aph(3'')-IIIa (16.6%), but resistance of isolates from food is also an effect of the presence of aph(2'')-Ib, aph(2'')-Ic, aph(2'')-Id genes. Resistance to tetracyclines was associated with the presence of tetM (43.7%), tetL (32.1%), tetK (14.6%), tetW (0.7%), and tetO (0.3%) genes. The ermB and ermA genes were found in 33.8% and 18.9% of isolates, respectively. Nearly half of the isolates contained a conjugative transposon of the Tn916/Tn1545 family. Enterococci are widely present in retail ready-to-eat meat products. Many isolated strains (including such species as E. casseliflavus, E. durans, E. hirae, and Enterococcus gallinarum) are antibiotic resistant and carry transferable resistance genes.

  16. Bioprotective potential of bacteriocinogenic Enterococcus gallinarum strains isolated from some Nigerian fermented foods, and of their bacteriocins.

    PubMed

    Oladipo, Iyabo C; Sanni, Abiodun I; Writachit, Chakraborty; Chakravorty, Somnath; Jana, Sayantan; Rudra, Deep S; Gacchui, Ratan; Swarnakar, Snehasikta

    2014-01-01

    Enterococcus gallinarum strains isolated from some Nigerian fermented foods were found to produce bacteriocins. The bacteriocins had a broad spectrum of activity against both Gram-positive and negative bacteria. The effects of the bacteriocins and bacteriocinogenic organ- isms on Staphylococcus aureus infections in rats were evaluated. Sprague-Dawley rats were infected with S. aureus MTCC 737 and treated with E. gallinarum T71 and different concentrations of the bacteriocins from E. gallinarum W211 and T71. Staphylococcus aureus infection caused significant upregulation of aspartate aminotransferase and alanine aminotransferase levels in sera of the infected rats. Moreover, gelatin zymography revealed that infected gastric tissues showed elevated matrix metalloproteinase-9 activity. Bacteriocin treatments reduced the MMP-9 activity and inhibited the expressions of both Tumour Necrosis Factor Alpha (TNF-α) and Interleukin-1 Beta (IL-1β) dose dependently, pointing to a potential role of the bacteriocins in attenuating inflammatory responses to Staphylococcus aureus infec- tion. Gastric and GIT damage caused by staphylococcal infection were reduced in the Enterococcus gallinarum T71 and bacteriocin-treated groups also dose dependently. We conclude that these bacteriocins may have useful biomedical applications.

  17. Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers

    PubMed Central

    López-Jiménez, Lidia; Viñas, Miguel; Vinuesa, Teresa

    2015-01-01

    Aim: To visualize by Atomic Force Microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Material and Methods: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by Atomic Force Microscopy (AFM) and its surface roughness determined. Results: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. Conclusions: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability. Key words:Atomic force microscopy, Er,Cr:YSGG laser, diode laser, Enterococcus faecalis, surface roughness. PMID:25475770

  18. Comparative Study of Bacteremias Caused by Enterococcus spp. with and without High-Level Resistance to Gentamicin

    PubMed Central

    Caballero-Granado, Francisco Javier; Cisneros, J. M.; Luque, R.; Torres-Tortosa, M.; Gamboa, F.; Díez, F.; Villanueva, J. L.; Pérez-Cano, R.; Pasquau, J.; Merino, D.; Menchero, A.; Mora, D.; López-Ruz, M. A.; Vergara, A.; Infecciosas, for the Grupo Andaluz Para El Estudio De Las Enfermedades

    1998-01-01

    A prospective, multicenter study was carried out over a period of 10 months. All patients with clinically significant bacteremia caused by Enterococcus spp. were included. The epidemiological, microbiological, clinical, and prognostic features and the relationship of these features to the presence of high-level resistance to gentamicin (HLRG) were studied. Ninety-three patients with enterococcal bacteremia were included, and 31 of these cases were caused by HLRG (33%). The multivariate analysis selected chronic renal failure, intensive care unit stay, previous use of antimicrobial agents, and Enterococcus faecalis species as the independent risk factors that influenced the development of HLRG. The strains with HLRG showed lower levels of susceptibility to penicillin and ciprofloxacin. Clinical features (except for chronic renal failure) were similar in both groups of patients. HLRG did not influence the prognosis for patients with enterococcal bacteremia in terms of either the crude mortality rate (29% for patients with bacteremia caused by enterococci with HLRG and 28% for patients not infected with strains with HLRG) or the hospital stay after the acquisition of enterococcal bacteremia. Hemodynamic compromise, inappropriate antimicrobial therapy, and mechanical ventilation were revealed in the multivariate analysis to be the independent risk factors for mortality. Prolonged hospitalization was associated with the nosocomial acquisition of bacteremia and polymicrobial infections. PMID:9466769

  19. A novel putative enterococcal pathogenicity island linked to the esp virulence gene of Enterococcus faecium and associated with epidemicity.

    PubMed

    Leavis, Helen; Top, Janetta; Shankar, Nathan; Borgen, Katrine; Bonten, Marc; van Embden, Jan; Willems, Rob J L

    2004-02-01

    Enterococcus faecalis harbors a virulence-associated surface protein encoded by the esp gene. This gene has been shown to be part of a 150-kb putative pathogenicity island. A gene similar to esp has recently been found in Enterococcus faecium isolates recovered from hospitalized patients. In the present study we analyzed the polymorphism in the esp gene of E. faecium, and we investigated the association of esp with neighboring chromosomal genes. The esp gene showed considerable sequence heterogeneity in the regions encoding the nonrepeat N- and C-terminal domains of the Esp protein as well as differences in the number of repeats. DNA sequencing of chromosomal regions flanking the esp gene of E. faecium revealed seven open reading frames, representing putative genes implicated in virulence, regulation of transcription, and antibiotic resistance. These flanking regions were invariably associated with the presence or absence of the esp gene in E. faecium, indicating that esp in E. faecium is part of a distinct genetic element. Because of the presence of virulence genes in this gene cluster, the lower G+C content relative to that of the genome, and the presence of esp in E. faecium isolates associated with nosocomial outbreaks and clinically documented infections, we conclude that this genetic element constitutes a putative pathogenicity island, the first one described in E. faecium. Except for the presence of esp and araC, this pathogenicity island is completely different from the esp-containing pathogenicity island previously disclosed in E. faecalis.

  20. The first report of the vanC₁ gene in Enterococcus faecium isolated from a human clinical specimen.

    PubMed

    Sun, Mingyue; Wang, Yue; Chen, Zhongju; Zhu, Xuhui; Tian, Lei; Sun, Ziyong

    2014-09-01

    The vanC₁ gene, which is chromosomally located, confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Enterococcus faecium TJ4031 was isolated from a blood culture and harbours the vanC₁gene. Polymerase chain reaction (PCR) assays were performed to detect vanXYc and vanTc genes. Only the vanXYc gene was found in the E. faecium TJ4031 isolate. The minimum inhibitory concentrations of vancomycin and teicoplanin were 2 µg/mL and 1 µg/mL, respectively. Real-time reverse transcription-PCR results revealed that the vanC₁ and vanXYc genes were not expressed. Pulsed-field gel electrophoresis and southern hybridisation results showed that the vanC₁ gene was encoded in the chromosome. E. faecalis isolated from animals has been reported to harbour vanC₁gene. However, this study is the first to report the presence of the vanC₁gene in E. faecium of human origin. Additionally, our research showed the vanC₁gene cannot serve as a species-specific gene of E. gallinarum and that it is able to be transferred between bacteria. Although the resistance marker is not expressed in the strain, our results showed that E. faecium could acquire the vanC₁gene from different species.

  1. Antibacterial, anti-inflammatory and probiotic potential of Enterococcus hirae isolated from the rumen of Bos primigenius.

    PubMed

    Arokiyaraj, Selvaraj; Hairul Islam, Villianur Ibrahim; Bharanidharan, R; Raveendar, Sebastian; Lee, Jinwook; Kim, Do Hyung; Oh, Young Kyoon; Kim, Eun-Kyung; Kim, Kyoung Hoon

    2014-07-01

    In the present study bacterial strains were isolated from the rumen fluids of Bos primigenius and investigated their in vitro probiotic properties with potent antibacterial activity and anti-inflammatory effects. 9 g positive bacterial isolates were obtained and three isolates could able to tolerate gastric conditions, high bile salt concentrations and exhibited significant bactericidal effect against the enteric pathogens Vibrio cholera, Enterococcus faecalis, Enterobacter aerogens, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Moreover it showed above 70% cell surface hydrophobicity, significant low-invasion ability and potential adherence capacity in Caco-2 cells when compared with the control. The proinflammatory cytokines (TNF-α) was greatly reduced in rumen bacteria treatment and ARBS-1 modulate the immune response by activating the IL-4 secretion in parallel to TNF-α suppression. The 16s rRNA gene sequence of the active isolates were identified as Enterococcus hirae (ARBS-1), Pediococcus acidilactici (ARBS-4) and Bacillus licheniformis (ARBS-7). This study revealed the probiotic bactericidal properties of E. hirae obtained from the rumen of B. primigenius with potential antibacterial and anti-inflammatory effects. Future studies with the strains may yield some novel probiotic product for livestock's.

  2. MurAA Is Required for Intrinsic Cephalosporin Resistance of Enterococcus faecalis

    PubMed Central

    Vesić, Dušanka

    2012-01-01

    Enterococcus faecalis is a low-GC Gram-positive bacterium that is intrinsically resistant to cephalosporins, antibiotics that target cell wall biosynthesis. To probe the mechanistic basis for intrinsic resistance, a library of transposon mutants was screened to identify E. faecalis strains that are highly susceptible to ceftriaxone, revealing a transposon mutant with a disruption in murAA. murAA is predicted to encode a UDP-N-acetylglucosamine 1-carboxyvinyl transferase that catalyzes the first committed step in peptidoglycan synthesis: phosphoenolpyruvate (PEP)-dependent conversion of UDP-N-acetylglucosamine to UDP-N-acetylglucosamine-enolpyruvate. In-frame deletion of murAA, but not its homolog in the E. faecalis genome (murAB), led to increased susceptibility of E. faecalis to cephalosporins. Furthermore, expression of murAA enhanced cephalosporin resistance in an E. faecalis mutant lacking IreK (formerly PrkC), a key kinase required for cephalosporin resistance. Further genetic analysis revealed that MurAA catalytic activity is necessary but not sufficient for this role. Collectively, our data indicate that MurAA and MurAB have distinct roles in E. faecalis physiology and suggest that MurAA possesses a unique property or activity that enables it to enhance intrinsic resistance of E. faecalis to cephalosporins. PMID:22290954

  3. Antiviral effects of a probiotic Enterococcus faecium strain against transmissible gastroenteritis coronavirus.

    PubMed

    Chai, Weidong; Burwinkel, Michael; Wang, Zhenya; Palissa, Christiane; Esch, Bettina; Twardziok, Sven; Rieger, Juliane; Wrede, Paul; Schmidt, Michael F G

    2013-04-01

    The enteropathogenic coronavirus transmissible gastroenteritis virus (TGEV) causes severe disease in young piglets. We have studied the protective effects of the probiotic Enterococcus faecium NCIMB 10415 (E. faecium), which is approved as a feed additive in the European Union, against TGEV infection. E. faecium was added to swine testicle (ST) cells before, concomitantly with, or after TGEV infection. Viability assays revealed that E. faecium led to a dose-dependent rescue of viability of TGEV-infected cells reaching nearly to complete protection. Virus yields of the E. faecium-treated cultures were reduced by up to three log10 units. Western blot analysis of purified TGEV revealed that the levels of all viral structural proteins were reduced after E. faecium treatment. Using transmission electron microscopy, we observed attachment of TGEV particles to the surface of E. faecium which might be a means to trap virus and to prevent infection. Increased production of nitric oxide in the cells treated with E. faecium and elevated expression of interleukin 6 and 8 pointed to stimulated cellular defense as a mechanism to fight TGEV infection.

  4. Cloning of the bile salt hydrolase (bsh) gene from Enterococcus faecium FAIR-E 345 and chromosomal location of bsh genes in food enterococci.

    PubMed

    Wijaya, Agus; Hermann, Anette; Abriouel, Hikmate; Specht, Ingrid; Yousif, Nuha M K; Holzapfel, Wilhelm H; Franz, Charles M A P

    2004-12-01

    Enterococcus faecium strain FAIR-E 345 isolated from food was shown to possess bile salt hydrolase (Bsh) activity in a plate screening assay and by high-performance liquid chromatography analysis. The bsh gene was cloned and sequenced. DNA sequence analysis revealed that it encoded a protein of 324 amino acids, with pI 4.877. A bsh gene probe was prepared from the cloned bsh gene and was used for probing plasmid and total genomic DNA of Bsh-positive enterococci isolated from food to determine the genomic location of their bsh genes. This probe was able to detect the bsh gene among total genomic DNA preparations but not from plasmid preparations of 10 plasmid-bearing Enterococcus strains. However, the probe could detect the bsh gene from total genomic DNA preparations of 12 Enterococcus strains that did not contain detectable plasmid DNA. In no cases did the probe hybridize with plasmid DNA preparations, suggesting that the bsh gene among enterococci is probably generally chromosomally encoded. This presumptive chromosomal location of bsh genes among food enterococci suggests that transfer of this trait by conjugative plasmids is unlikely.

  5. Effects of pressure and pressure cycling on disinfection of Enterococcus sp. in seawater using pressurized carbon dioxide with different content rates.

    PubMed

    Dang, Loc T T; Imai, Tsuyoshi; Le, Tuan V; Nishihara, Satoshi; Higuchi, Takaya; Nguyen, Mai K D; Kanno, Ariyo; Yamamoto, Koichi; Sekine, Masahiko

    2016-09-18

    Interest is growing in a disinfection technique for water treatment without disinfection byproducts. This study presents the result of using a liquid-film-forming apparatus at less than 1.0 MPa for disinfection of seawater. The sensitivity of Enterococcus sp. (ATCC 202155) to the pressurized carbon dioxide (CO2) was examined under various conditions of pressure cycling, pressure, working volume ratio (WVR), and CO2 content rate. The key influences on frequency and magnitude of pressure cycling in enhancing Enterococcus sp. inactivation are elucidated. The results reveal strong correlation between pressure cycling and inactivation efficiency (P-value < 0.001). The outcome of linear regression model analysis suggests that the model can explain 93%, 85%, and 89% of the inactivation efficiency of (25% CO2 + 75% N2), (50% CO2 + 50% N2), and 100% CO2, respectively. The predicted value was fit with experimental results (p-value <0.05). Under identical treatment conditions (pressure = 0.9 MPa, ΔP = 0.14 MPa, 70% WVR, and 20 ± 1°C), treatment with pressurized CO2 (100% purity) resulted in complete inactivation 5.2 log of Enterococcus sp. after 70 cycles within 20 min. The Enterococcus sp. inactivation of pressurized CO2 followed first-order reaction kinetics. The smallest D-value (largest k-value) was induced by pressurized CO2 (100% purity) at 0.9 MPa, which was obtained at 3.85 min (0.5988 min(-1), R(2) ≥ 0.95). The findings could provide an effective method for enhanced bactericidal performance of pressurized CO2, to address recently emerging problems in water disinfection.

  6. Application of bacteriocinogenic Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch in the control of Listeria monocytogenes in fresh Minas cheese.

    PubMed

    Vera Pingitore, Esteban; Todorov, Svetoslav Dimitrov; Sesma, Fernando; Franco, Bernadette Dora Gombossy de Melo

    2012-10-01

    Several strains of Enterococcus spp. are capable of producing bacteriocins with antimicrobial activity against important bacterial pathogens in dairy products. In this study, the bacteriocins produced by two Enterococcus strains (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch), isolated from cheeses, were characterized and tested for their capability to control growth of Listeria monocytogenes 426 in experimentally contaminated fresh Minas cheese during refrigerated storage. Both strains were active against a variety of pathogenic and non-pathogenic microorganisms and bacteriocin absorption to various L. monocytogenes, Enterococcus faecalis ATCC 19443 and Lactobacillus sakei ATCC 15521 varied according to the strain and the testing conditions (pH, temperature, presence of salts and surfactants). Growth of L. monocytogenes 426 was inhibited in cheeses containing E. mundtii CRL35 up to 12 days at 8 °C, evidencing a bacteriostatic effect. E. faecium ST88Ch was less effective, as the bacteriostatic affect occurred only after 6 days at 8 °C. In cheeses containing nisin (12.5 mg/kg), less than one log reduction was observed. This research underlines the potential application of E. mundtii CRL35 in the control of L. monocytogenes in Minas cheese.

  7. In vitro susceptibility studies of vancomycin-resistant Enterococcus faecalis.

    PubMed Central

    Sahm, D F; Kissinger, J; Gilmore, M S; Murray, P R; Mulder, R; Solliday, J; Clarke, B

    1989-01-01

    Vancomycin resistance exhibited by Enterococcus faecalis isolates V583, V586, and V587 is described. The vancomycin MICs ranged from 32 to 64 micrograms/ml. Although resistant to vancomycin, the isolates were susceptible to teicoplanin (MIC, less than or equal to 0.5 micrograms/ml). Such a glycopeptide susceptibility profile has not been previously described for E. faecalis. Time kill studies showed that vancomycin resistance adversely affected the synergistic activity that vancomycin and aminoglycoside combinations usually demonstrate against enterococci. However, the ability to detect vancomycin resistance varied with the susceptibility testing method used. Whereas broth microdilution, broth macrodilution, and agar dilution methods detected resistance, disk-agar diffusion and the AutoMicrobic system Gram-Positive GPS-A susceptibility card (Vitek Systems Inc., Hazelwood, Mo.) did not. To detect vancomycin resistance reliably and establish the incidence of such E. faecalis isolates, adjustments in some susceptibility testing methods may be necessary. PMID:2554802

  8. Candida albicans and Enterococcus faecalis in the gut

    PubMed Central

    Garsin, Danielle A; Lorenz, Michael C

    2013-01-01

    The fungus Candida albicans and the gram-positive bacterium Enterococcus faecalis are both normal residents of the human gut microbiome and cause opportunistic disseminated infections in immunocompromised individuals. Using a nematode infection model, we recently showed that co-infection resulted in less pathology and less mortality than infection with either species alone and this was partly explained by an interkingdom signaling event in which a bacterial-derived product inhibits hyphal morphogenesis of C. albicans. In this addendum we discuss these findings in the contest of other described bacterial-fungal interactions and recent data suggesting a potentially synergistic relationship between these two species in the mouse gut as well. We suggest that E. faecalis and C. albicans promote a mutually beneficial association with the host, in effect choosing a commensal lifestyle over a pathogenic one. PMID:23941906

  9. In vitro activity of Amazon plant extracts against Enterococcus faecalis

    PubMed Central

    de Castilho, Adriana Lígia; da Silva, Juliana Paola Correa; Saraceni, Cintia Helena Coury; Díaz, Ingrit Elida Collantes; Paciencia, Mateus Luís Barradas; Varella, Antonio Drauzio; Suffredini, Ivana Barbosa

    2014-01-01

    Previous studies analyzing 2,200 plant extracts indicated anti-enterococcal activity in 25 extracts obtained from Brazilian forests’ plants. In the present study, these extracts were subjected to microdilution broth assay (MDBA) and disk diffusion assay (DDA) using planktonic Enterococcus faecalis ATCC® 29212™ and were submitted to phytochemical analysis in TLC and HPLC. Three extracts obtained from Ipomoea alba (MIC < 40 μg/mL), Diclinanona calycina (MIC ≤ 40 μg/mL) and Moronobea coccinea (40 < MIC < 80 μg/mL; MBC = 80 μg/mL) showed significant bactericidal activity in the MDBA and four extracts obtained from I. alba (14.04 ± 0.55 mm diameter) S. globulifera (14.43 ± 0.33 mm and 12.18 ± 0.28 mm diameter) and Connarus ruber var. ruber (13.13 ± 0.18 mm diameter) were active in DDA. Residues H2O obtained from Psidium densicomum (mean of 16.78 mm diameter) and from Stryphnodendron pulcherrimum (mean of 15.97 mm diameter) have shown an improved antibacterial activity after fractionation if compared to that obtained from the respective crude extracts. Antioxidant activity was observed in some residues of the active extracts. TLC analysis showed that phenolic compounds are likely to be found in active extracts. Three molecules were isolated from S. globulifera and were identified by 13C NMR lupeol, α-amyrin and 3β-hydroxyglutin-5-ene. The present chemical and biological findings suggest that these extracts are a potential source of new anti-Enterococcus compounds to be introduced in endodontic therapy. PMID:25477906

  10. Antimicrobial resistance and virulence of Enterococcus faecalis isolated from retail food

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although enterococci are considered opportunistic nosocomial pathogens, their contribution to food-borne illnesses via dissemination through retail food remains undefined. In this study, prevalence and association of antimicrobial resistance and virulence factors of 80 Enterococcus faecalis isolate...

  11. Draft Genome Sequence of an Enterococcus faecalis ATCC 19433 Siphovirus Isolated from Raw Domestic Sewage

    PubMed Central

    Ly, Melissa; Pride, David T.; Toranzos, Gary A.

    2017-01-01

    ABSTRACT We previously isolated and characterized an Enterococcus faecalis ATCC 19433 siphovirus from raw domestic sewage as a viral indicator of human fecal pollution. Here, we report the draft genome sequence of this bacteriophage. PMID:28104647

  12. Draft Genome Sequence of an Enterococcus faecalis ATCC 19433 Siphovirus Isolated from Raw Domestic Sewage.

    PubMed

    Santiago-Rodriguez, Tasha M; Ly, Melissa; Pride, David T; Toranzos, Gary A

    2017-01-19

    We previously isolated and characterized an Enterococcus faecalis ATCC 19433 siphovirus from raw domestic sewage as a viral indicator of human fecal pollution. Here, we report the draft genome sequence of this bacteriophage.

  13. Macrolide, glycopeptide resistance and virulence genes in Enterococcus species isolates from dairy cattle.

    PubMed

    Iweriebor, Benson C; Obi, Larry C; Okoh, Anthony I

    2016-07-01

    The genus Enterococcus is known to possess the capacity to acquire and disseminate antimicrobial resistant determinants alongside the ability to produce various virulence genes that enables it to establish infections. We assessed the prevalence and antibiogram profiles of Enterococcus spp. in faecal samples of dairy cattle. Faecal swab samples were collected from 400 dairy cattle from two commercial cattle farms in two rural communities in the Eastern Cape, South Africa. Confirmation of enterococci isolates was carried out by PCR targeting of the tuf gene. Species delineation was by species-specific primers targeting the superoxide dismutase (sod A) gene in a multiplex PCR assay. Isolates were screened for the presence of the following virulence genes (ace, gel E, esp, efa A, cyl A and hyl E) and antimicrobial resistance determinants to erythromycin, vancomycin and streptomycin were evaluated molecularly. A total of 340 isolates were confirmed as belonging to the genus Enterococcus . Species distribution among the isolates consisted of Enterococcus faecium (52.94 %) and Enterococcus durans (23.53 %) in preponderance compared to the three other species, namely Enterococcus faecalis (8.8 %), Enterococcus hirae (8.6 %) and Enterococcus casseliflavus (5.9 %). All were resistant to vancomycin, while 99 % showed resistance to aminoglycoside and 94 % to macrolide. Three virulence genes (ace, gel E and esp) were detected in almost all the confirmed isolates. The resistance determinants van B (19.7 %), van C1 (25 %), van C2/3 (26.3 %) erm B (40.29 %) and str A (50.88 %) were detected among the isolates. A high prevalence of multidrug-resistant enterococci isolates was detected in this study and the genetic repertoire to survive in the presence of antimicrobial agents was present in these organisms.

  14. Longer Intestinal Persistence of Enterococcus faecalis Compared to Enterococcus faecium Clones in Intensive-Care-Unit Patients▿

    PubMed Central

    Ruiz-Garbajosa, Patricia; del Campo, Rosa; Coque, Teresa M.; Asensio, Angel; Bonten, Marc; Willems, Rob; Baquero, Fernando; Cantón, Rafael

    2009-01-01

    The dynamics of intestinal colonization with enterococcal clones in intensive-care-unit (ICU) patients was evaluated. Eight patients admitted directly to the neurosurgical ICU at the Ramón y Cajal University Hospital (Madrid, Spain) from the community and with no overlapping stay during a 10-month period in 2006 were studied. Rectal swab specimens were collected on admission and daily until the patients were discharged. Clonality was determined by pulsed-field gel electrophoresis and multilocus sequence typing. Clonal colonization dynamics were estimated by using two new parameters: the clonal diversity per patient per day (CDPD) and the clonal persistence ratio (CPR). Enterococcus faecalis isolates (n = 123) and Enterococcus faecium isolates (n = 66) were resolved into 13 and 15 clones, respectively. The CDPD of E. faecalis steadily increased during admission, and E. faecalis showed a higher (P = 0.001) CPR value than E. faecium (0.86 and 0.42, respectively). E. faecium, with the exception of an ampicillin-resistant clone belonging to clonal complex 17, frequently appeared as a short-term colonizer, even though the E. faecalis clones had significantly (P = 0.03) more days under antibiotic exposure than E. faecium (77.5 and 65 days/100 colonization days, respectively). E. faecalis had a longer persistence than E. faecium, except for the CC17 ampicillin-resistant clone, and E. faecalis showed a cumulative increase in CDPD, whereas E. faecium did not. CDPD and CPR were useful for measuring the dynamics of intestinal colonization with enterococcal clones. PMID:19052172

  15. Comparison of Enterococcus faecium and Enterococcus faecalis Strains Isolated from Water and Clinical Samples: Antimicrobial Susceptibility and Genetic Relationships

    PubMed Central

    Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I.; Agis-Juárez, Raúl A.; Huebner, Johannes; López-Vidal, Yolanda

    2013-01-01

    Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species. PMID:23560050

  16. Multiple antibiotic resistances of Enterococcus isolates from raw or sand-filtered sewage.

    PubMed

    Xu, Junyi; Gallert, Claudia; Winter, Josef

    2007-02-01

    Fifty antibiotic-resistant Enterococcus strains were isolated from raw sewage of a wastewater treatment plant and from the same sewage after trickling through a 25-cm sand column, which retained >99% of the initial population. All 50 Enterococcus isolates were resistant against triple sulfa and trimethoprim/sulfamethoxazole and none were resistant against vancomycin. Most of the isolates from raw sewage were resistant to more antibiotics than the isolates from sand column effluent. One Enterococcus isolate from raw sewage (no. 61) and one Enterococcus isolate from sand column effluent (no. 95) had ten antibiotic resistances each. Isolate no. 95 maintained its resistances in the absence of antibiotics during the whole study. It was compared with isolate no. 70, which was one of the isolates, being resistant only against the two sulfonamides. Phenotypically and biochemically, the two organisms were strains of Enterococcus faecalis. Sequence analysis of partical 16S rDNA allowed alignment of isolate no. 95 as a strain of Enterococcus faecium and of isolate no. 70 as a strain of E. faecalis. E. faecium strain no. 95 carried at least six different plasmids, whereas for E. faecalis strain no. 70, no discrete plasmid band was seen on the gels.

  17. Microevolutionary Events Involving Narrow Host Plasmids Influences Local Fixation of Vancomycin-Resistance in Enterococcus Populations

    PubMed Central

    Freitas, Ana R.; Novais, Carla; Tedim, Ana P.; Francia, María Victoria; Baquero, Fernando; Peixe, Luísa; Coque, Teresa M.

    2013-01-01

    Vancomycin-resistance in enterococci (VRE) is associated with isolates within ST18, ST17, ST78 Enterococcus faecium (Efm) and ST6 Enterococcus faecalis (Efs) human adapted lineages. Despite of its global spread, vancomycin resistance rates in enterococcal populations greatly vary temporally and geographically. Portugal is one of the European countries where Tn1546 (vanA) is consistently found in a variety of environments. A comprehensive multi-hierarchical analysis of VRE isolates (75 Efm and 29 Efs) from Portuguese hospitals and aquatic surroundings (1996–2008) was performed to clarify the local dynamics of VRE. Clonal relatedness was established by PFGE and MLST while plasmid characterization comprised the analysis of known relaxases, rep initiator proteins and toxin-antitoxin systems (TA) by PCR-based typing schemes, RFLP comparison, hybridization and sequencing. Tn1546 variants were characterized by PCR overlapping/sequencing. Intra- and inter-hospital dissemination of Efm ST18, ST132 and ST280 and Efs ST6 clones, carrying rolling-circle (pEFNP1/pRI1) and theta-replicating (pCIZ2-like, Inc18, pHTβ-like, two pRUM-variants, pLG1-like, and pheromone-responsive) plasmids was documented. Tn1546 variants, mostly containing ISEf1 or IS1216, were located on plasmids (30–150 kb) with a high degree of mosaicism and heterogeneous RFLP patterns that seem to have resulted from the interplay between broad host Inc18 plasmids (pIP501, pRE25, pEF1), and narrow host RepA_N plasmids (pRUM, pAD1-like). TAs of Inc18 (ω-ε-ζ) and pRUM (Axe-Txe) plasmids were infrequently detected. Some plasmid chimeras were persistently recovered over years from different clonal lineages. This work represents the first multi-hierarchical analysis of VRE, revealing a frequent recombinatorial diversification of a limited number of interacting clonal backgrounds, plasmids and transposons at local scale. These interactions provide a continuous process of parapatric clonalization driving a full

  18. [In vitro susceptibility of Enterococcus strains to high level aminoglycosides and heavy metals].

    PubMed

    Nakipoğlu, Yaşar; Gümüş, Defne; Sertel Selale, Deniz; Küçüker, Mine Ang

    2009-10-01

    /or teicoplanin) and heavy metals (lead and arsenic and/or mercury) were detected concurrently in 28 (%71.8) of the strains. It was considered remarkable that all of the isolates were resistant to lead and there was no difference between antibiotic-resistant and-susceptible strains in terms of lead resistance. In conclusion, further investigations are needed to reveal the extreme lead resistance and the relations between antibiotic and heavy metal resistances in clinical enterococcus strains.

  19. The Spx Regulator Modulates Stress Responses and Virulence in Enterococcus faecalis

    PubMed Central

    Kajfasz, Jessica K.; Mendoza, Jorge E.; Gaca, Anthony O.; Miller, James H.; Koselny, Kristy A.; Giambiagi-deMarval, Marcia; Wellington, Melanie; Abranches, Jacqueline

    2012-01-01

    The ability to cope with endogenous or host-generated reactive oxygen species is considered a key virulence attribute of the opportunistic pathogen Enterococcus faecalis, a leading cause of hospital-acquired infections. In this study, we used in silico and mutational analyses to identify and characterize the role of the Spx global regulator in oxidative stress tolerance and virulence in E. faecalis. While the Δspx strain grew as well as the wild-type strain under anaerobic conditions, the mutant strain exhibited impaired growth under aerobic conditions and was highly sensitive to oxidative stress agents. The spx mutant strain was also sensitive to a variety of other stressful conditions, including antibiotic stress and killing by the mouse-derived macrophage cell line J774. Using a murine model of foreign body-associated peritonitis, we demonstrated that the ability of the Δspx strain to colonize the peritoneum and disseminate in the bloodstream was significantly reduced compared to that of the parent strain. Transcriptional analysis revealed that a large number of known oxidative stress genes are under positive control by Spx. Collectively, our results show that Spx is a major stress gene regulator and is implicated in the pathophysiology of E. faecalis. The relationship of Spx to other oxidative stress regulators is also discussed. PMID:22508863

  20. Characterization of Vancomycin-Resistant Enterococcus faecium Isolated from Swine in Three Michigan Counties▿ ‖

    PubMed Central

    Donabedian, Susan M.; Perri, Mary Beth; Abdujamilova, Nodira; Gordoncillo, Mary Joy; Naqvi, Amir; Reyes, Katherine C.; Zervos, Marcus J.; Bartlett, Paul

    2010-01-01

    Vancomycin-resistant enterococci are a major cause of nosocomial infections but are rarely found in humans in the community and have not been identified in food animals in the United States. We evaluated a total of 360 fecal specimens from humans and their animals being raised for exhibit at three county fairs in Michigan. Fecal samples from 158 humans, 55 swine, 50 cattle, 25 horses, 57 sheep, 14 goats, and 1 llama were obtained and plated onto Enterococcosel agar containing 16 μg/ml of vancomycin. Vancomycin-resistant Enterococcus faecium (VREF) was isolated from six pigs but not from humans or any animal other than pigs. All six VREF isolates had a MIC to vancomycin of ≥256 μg/ml and contained the vanA gene. Pulsed-field gel electrophoresis (PFGE) patterns of the six VREF isolates were ≥80% similar. Multilocus sequence typing (MLST) revealed sequence type 5 (ST5) (n = 2), ST6 (n = 3), and ST185 (n = 1), which are E. faecium sequence types belonging to clonal complex 5 (CC5). These findings show the dissemination of VREF strains among pigs in three Michigan counties. This is the first report of VRE found in food animals in the United States. PMID:20739498

  1. Fingerprinting of poultry isolates of Enterococcus cecorum using three molecular typing methods.

    PubMed

    Wijetunge, Dona Saumya; Dunn, Patricia; Wallner-Pendleton, Eva; Lintner, Valerie; Lu, Huaguang; Kariyawasam, Subhashinie

    2012-11-01

    Enterococcus cecorum is an emerging challenge to the broiler industry. The organism has been implicated in septicemia, spondylitis, arthritis, and osteomyelitis in commercial broilers and broiler breeders, which lead to economic losses attributed to increased mortality and culling rates, decreased average processing weights, and increased feed conversion ratios. The current study evaluated the genetic variability of 30 clinical isolates of E. cecorum from outbreaks in Pennsylvania, using 3 molecular typing methods, namely, pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA analysis, and enterobacterial repetitive intergenic consensus-PCR (polymerase chain reaction), in order to understand their genetic relatedness and to identify possible pathogenic clones. The study revealed the existence of genotypic polymorphism among E. cecorum associated with clinical disease. Of the 3 typing methods used, PFGE analysis demonstrated higher genetic variability of E. cecorum isolates compared to PCR-based methods. Also, each molecular typing method was evaluated in terms of typeability, discriminatory power, and reproducibility for application of these typing methods in fingerprinting of E. cecorum in future reference. Pulsed-field gel electrophoresis provided the most reliable results with greater discriminatory power and higher reproducibility compared to the 2 PCR-based methods.

  2. Mechanisms of Allosteric Activation and Inhibition of the Deoxyribonucleoside Triphosphate Triphosphohydrolase from Enterococcus faecalis*♦

    PubMed Central

    Vorontsov, Ivan I.; Wu, Ying; DeLucia, Maria; Minasov, George; Mehrens, Jennifer; Shuvalova, Ludmilla; Anderson, Wayne F.; Ahn, Jinwoo

    2014-01-01

    EF1143 from Enterococcus faecalis, a life-threatening pathogen that is resistant to common antibiotics, is a homo-tetrameric deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase (dNTPase), converting dNTPs into the deoxyribonucleosides and triphosphate. The dNTPase activity of EF1143 is regulated by canonical dNTPs, which simultaneously act as substrates and activity modulators. Previous crystal structures of apo-EF1143 and the protein bound to both dGTP and dATP suggested allosteric regulation of its enzymatic activity by dGTP binding at four identical allosteric sites. However, whether and how other canonical dNTPs regulate the enzyme activity was not defined. Here, we present the crystal structure of EF1143 in complex with dGTP and dTTP. The new structure reveals that the tetrameric EF1143 contains four additional secondary allosteric sites adjacent to the previously identified dGTP-binding primary regulatory sites. Structural and enzyme kinetic studies indicate that dGTP binding to the first allosteric site, with nanomolar affinity, is a prerequisite for substrate docking and hydrolysis. Then, the presence of a particular dNTP in the second site either enhances or inhibits the dNTPase activity of EF1143. Our results provide the first mechanistic insight into dNTP-mediated regulation of dNTPase activity. PMID:24338016

  3. SlyA Is a Transcriptional Regulator Involved in the Virulence of Enterococcus faecalis▿

    PubMed Central

    Michaux, Charlotte; Sanguinetti, Maurizio; Reffuveille, Fany; Auffray, Yanick; Posteraro, Brunella; Gilmore, Michael S.; Hartke, Axel; Giard, Jean-Christophe

    2011-01-01

    Phylogenetic analysis of the crystal structure of the Enterococcus faecalis SlyA (EF_3002) transcriptional factor places it between the SlyA and MarR regulator subfamilies. Proteins of these families are often involved in the regulation of genes important for bacterial virulence and stress response. To gather evidence for the role of this putative regulator in E. faecalis biology, we dissected the genetic organization of the slyA-EF_3001 locus and constructed a slyA deletion mutant as well as complemented strains. Interestingly, compared to the wild-type parent, the ΔslyA mutant is more virulent in an insect infection model (Galleria mellonella), exhibits increased persistence in mouse kidneys and liver, and survives better inside peritoneal macrophages. In order to identify a possible SlyA regulon, global microarray transcriptional analysis was performed. This study revealed that the slyA-EF_3001 locus appears to be autoregulated and that 117 genes were differentially regulated in the ΔslyA mutant. In the mutant strain, 111 were underexpressed and 6 overexpressed, indicating that SlyA functions mainly as an activator of transcription. PMID:21536798

  4. TLR-7 activation enhances IL-22–mediated colonization resistance against vancomycin-resistant enterococcus

    PubMed Central

    Abt, Michael C.; Buffie, Charlie G.; Sušac, Bože; Becattini, Simone; Carter, Rebecca A.; Leiner, Ingrid; Keith, James W.; Artis, David; Osborne, Lisa C.; Pamer, Eric G.

    2016-01-01

    Antibiotic administration can disrupt the intestinal microbiota and down-regulate innate immune defenses, compromising colonization resistance against orally acquired bacterial pathogens. Vancomycin-resistant Enterococcus faecium (VRE), a major cause of antibiotic-resistant infections in hospitalized patients, thrives in the intestine when colonization resistance is compromised, achieving extremely high densities that can lead to bloodstream invasion and sepsis. Viral infections, by mechanisms that remain incompletely defined, can stimulate resistance against invading bacterial pathogens. We report that murine norovirus infection reduces the density of VRE in the intestinal tract of mice with antibiotic-induced loss of colonization resistance. Resiquimod (R848), a synthetic ligand for Toll-like receptor 7 (TLR-7) that stimulates antiviral innate immune defenses, restores expression of the antimicrobial peptide Reg3γ and reestablishes colonization resistance against VRE in antibiotic-treated mice. Orally administered R848 triggers TLR-7 on CD11c+ dendritic cells, inducing interleukin-23 (IL-23) expression followed by a burst of IL-22 secretion by innate lymphoid cells, leading to Reg3γ expression and restoration of colonization resistance against VRE. Our findings reveal that an orally bioavailable TLR-7 ligand that stimulates innate antiviral immune defenses in the intestine restores colonization resistance against a highly antibiotic-resistant bacterial pathogen. PMID:26912904

  5. RelA Mutant Enterococcus faecium with Multiantibiotic Tolerance Arising in an Immunocompromised Host

    PubMed Central

    Honsa, Erin S.; Mhaissen, Mohammed N.; Frank, Matthew; Shaker, Jessica; Iverson, Amy; Rubnitz, Jeffrey; Hayden, Randall T.; Lee, Richard E.; Rock, Charles O.; Tuomanen, Elaine I.

    2017-01-01

    ABSTRACT Serious bacterial infections in immunocompromised patients require highly effective antibacterial therapy for cure, and thus, this setting may reveal novel mechanisms by which bacteria circumvent antibiotics in the absence of immune pressure. Here, an infant with leukemia developed vancomycin-resistant Enterococcus faecium (VRE) bacteremia that persisted for 26 days despite appropriate antibiotic therapy. Sequencing of 22 consecutive VRE isolates identified the emergence of a single missense mutation (L152F) in relA, which constitutively activated the stringent response, resulting in elevated baseline levels of the alarmone guanosine tetraphosphate (ppGpp). Although the mutant remained susceptible to both linezolid and daptomycin in clinical MIC testing and during planktonic growth, it demonstrated tolerance to high doses of both antibiotics when growing in a biofilm. This biofilm-specific gain in resistance was reflected in the broad shift in transcript levels caused by the mutation. Only an experimental biofilm-targeting ClpP-activating antibiotic was able to kill the mutant strain in an established biofilm. The relA mutation was associated with a fitness trade-off, forming smaller and less-well-populated biofilms on biological surfaces. We conclude that clinically relevant relA mutations can emerge during prolonged VRE infection, causing baseline activation of the stringent response, subsequent antibiotic tolerance, and delayed eradication in an immunocompromised state. PMID:28049149

  6. Probiotic assessment of Enterococcus durans 6HL and Lactococcus lactis 2HL isolated from vaginal microflora.

    PubMed

    Nami, Yousef; Abdullah, Norhafizah; Haghshenas, Babak; Radiah, Dayang; Rosli, Rozita; Khosroushahi, Ahmad Yari

    2014-08-01

    Forty-five lactic acid bacteria (LAB) were isolated from the vaginal specimens of healthy fertile women, and the identities of the bacteria were confirmed by sequencing of their 16S rDNA genes. Among these bacteria, only four isolates were able to resist and survive in low pH, bile salts and simulated in vitro digestion conditions. Lactococcus lactis 2HL, Enterococcus durans 6HL, Lactobacillus acidophilus 36YL and Lactobacillus plantarum 5BL showed the best resistance to these conditions. These strains were evaluated further to assess their ability to adhere to human intestinal Caco-2 cells. Lactococcus lactis 2HL and E. durans 6HL were the most adherent strains. In vitro tests under neutralized pH proved the antimicrobial activity of both strains. Results revealed that the growth of Escherichia coli O26, Staphylococcus aureus and Shigella flexneri was suppressed by both LAB strains. The antibiotic susceptibility tests showed that these strains were sensitive to all nine antibiotics: vancomycin, tetracycline, ampicillin, penicillin, gentamicin, erythromycin, clindamycin, sulfamethoxazole and chloramphenicol. These data suggest that E. durans 6HL and Lactococcus lactis 2HL could be examined further for their useful properties and could be developed as new probiotics.

  7. The enterococcal surface protein, Esp, is involved in Enterococcus faecalis biofilm formation.

    PubMed

    Toledo-Arana, A; Valle, J; Solano, C; Arrizubieta, M J; Cucarella, C; Lamata, M; Amorena, B; Leiva, J; Penadés, J R; Lasa, I

    2001-10-01

    The enterococcal surface protein, Esp, is a high-molecular-weight surface protein of unknown function whose frequency is significantly increased among infection-derived Enterococcus faecalis isolates. In this work, a global structural similarity was found between Bap, a biofilm-associated protein of Staphylococcus aureus, and Esp. Analysis of the relationship between the presence of the Esp-encoding gene (esp) and the biofilm formation capacity in E. faecalis demonstrated that the presence of the esp gene is highly associated (P < 0.0001) with the capacity of E. faecalis to form a biofilm on a polystyrene surface, since 93.5% of the E. faecalis esp-positive isolates were capable of forming a biofilm. Moreover, none of the E. faecalis esp-deficient isolates were biofilm producers. Depending on the E. faecalis isolate, insertional mutagenesis of esp caused either a complete loss of the biofilm formation phenotype or no apparent phenotypic defect. Complementation studies revealed that Esp expression in an E. faecalis esp-deficient strain promoted primary attachment and biofilm formation on polystyrene and polyvinyl chloride plastic from urine collection bags. Together, these results demonstrate that (i) biofilm formation capacity is widespread among clinical E. faecalis isolates, (ii) the biofilm formation capacity is restricted to the E. faecalis strains harboring esp, and (iii) Esp promotes primary attachment and biofilm formation of E. faecalis on abiotic surfaces.

  8. Inhibition of initial adhesion of uropathogenic Enterococcus faecalis by biosurfactants from Lactobacillus isolates.

    PubMed Central

    Velraeds, M M; van der Mei, H C; Reid, G; Busscher, H J

    1996-01-01

    In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber. The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced by an average of 77%. The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp. rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents. PMID:8787394

  9. Genetic Diversity and Antibiotic Resistance of Enterococcus faecalis Isolates from Traditional Korean Fermented Soybean Foods.

    PubMed

    Lee, Jong-Hoon; Shin, Donghun; Lee, Bitnara; Lee, Inhyung; Jeong, Do-Won

    2017-02-24

    Eighty-five Enterococcus faecalis isolates collected from animals (40 isolates), Meju (Korean fermented soybean product; 27 isolates), humans (10 isolates), and various environmental samples (eight isolates) were subjected to multilocus sequence typing (MLST) to identify genetic differences between samples of different origins. MLST analysis resulted in 44 sequence types (STs), and the eBURST algorithm clustered the STs into 21 clonal complexes (CCs) and 17 singletons. The predominant STs, ST695 (21.1%, 18/85) and ST694 (9.4%, 8/85), were singletons, and only contained isolates originating from Meju. None of the STs in the current study belonged to CC2 or CC9, which comprise clinical isolates with high levels of antibiotic resistance. The E. faecalis isolates showed the highest rates of resistance to tetracycline (32.9%), followed by erythromycin (9.4%) and vancomycin (2.4%). All isolates from Meju were sensitive to these three antibiotics. Hence, MLST uncovered genetic diversity within E. faecalis, and clustering of the STs using eBURST revealed a correlation between the genotypes and origins of the isolates.

  10. Efficacy of Atmospheric Pressure Plasma as an Antibacterial Agent Against Enterococcus Faecalis in Vitro

    NASA Astrophysics Data System (ADS)

    Cao, Yingguang; Yang, Ping; Lu, Xinpei; Xiong, Zilan; Ye, Tao; Xiong, Qing; Sun, Ziyong

    2011-02-01

    Enterococcus faecalis (E. faecalis) is a microorganism that can survive extreme challenges in obturated root canals. The aim of this study was to evaluate the efficacy of a non-thermal atmospheric pressure plasma plume against E. faecalis in vitro. A non-thermal atmospheric pressure plasma jet device which could generate a cold plasma plume carrying a peak current of 300 mA was used. The antibacterial efficacy of this device against E. faecalis and its biofilm under different conditions was detected. The antibacterial efficacy of the plasma against E. faecalis and Staphylococcus aureus (S. aureus) was also evaluated. After plasma treatment, the average diameter of inhibition zone on S. aureus and E. faecalis was 2.62±0.26 cm and 1.06±0.30 cm, respectively (P < 0.05). The diameter was increased with prolongation of the treatment duration. The diameters of inhibition zone of the sealed Petri dishes were larger than those of the uncovered Petri dishes. There was significant difference in colony-forming units between plasma group and control group on E. faecalis biofilm (P < 0.01). The transmission electron microscopy revealed that the ultrastructural changes cytoderm of E. faecalis were observed after treatment for 2 min. It is concluded that the non-thermal atmospheric pressure plasma could serve as an effective adjunct to standard endodontic microbial treatment.

  11. Crystal structure of enterococcus faecalis sly A-like transcriptional factor.

    SciTech Connect

    Wu, R.; Zhang, R.; Zagnitko, O.; Dementieva, I.; Maltsev, N.; Watson, J. D.; Laskowski, R.; Gornicki, P.; Joachimiak, A.; Univ. of Chicago; European Bioinformatics Inst.

    2003-05-30

    The crystal structure of a SlyA transcriptional regulator at 1.6 {angstrom} resolution is presented, and structural relationships between members of the MarR/SlyA family are discussed. The SlyA family, which includes SlyA, Rap, Hor, and RovA proteins, is widely distributed in bacterial and archaeal genomes. Current evidence suggests that SlyA-like factors act as repressors, activators, and modulators of gene transcription. These proteins have been shown to up-regulate the expression of molecular chaperones, acid-resistance proteins, and cytolysin, and down-regulate several biosynthetic enzymes. The structure of SlyA from Enterococcus faecalis, determined as a part of an ongoing structural genomics initiative (www.mcsg.anl.gov), revealed the same winged helix DNA-binding motif that was recently found in the MarR repressor from Escherichia coli and the MexR repressor from Pseudomonas aeruginosa, a sequence homologue of MarR. Phylogenetic analysis of the MarR/SlyA family suggests that Sly is placed between the SlyA and MarR subfamilies and shows significant sequence similarity to members of both subfamilies.

  12. Structural Studies on Cytosolic Domain of Magnesium Transporter MgtE from Enterococcus faecalis

    SciTech Connect

    Ragumani, S.; Sauder, J; Burley, S; Swaminathan, S

    2009-01-01

    Magnesium (Mg{sup 2+}) is an essential element for growth and maintenance of living cells. It acts as a cofactor for many enzymes and is also essential for stability of the plasma membrane. There are two distinct classes of magnesium transporters identified in bacteria that convey Mg{sup 2+} from periplasm to cytoplasm [ATPase-dependent (MgtA and MgtB) and constitutively active (CorA and MgtE)]. Previously published work on Mg{sup 2+} transporters yielded structures of full length MgtE from Thermus thermophilus, determined at 3.5 {angstrom} resolution, and its cytoplasmic domain with and without bond Mg{sup 2+} determined at 2.3 and 3.9 {angstrom} resolution, respectively. Here, they report the crystal structure of the Mg{sup 2+} bound form of the cytosolic portion of MgtE (residues 6-262) from Enterococcus faecalis at 2.2 {angstrom} resolution. The present structure and magnesium bound cytosolic domain structure from T. thermophilus (PDB ID: 2YVY) are structurally similar. Three magnesium binding sites are common to both MgtE full length and the present structure. Their work revealed an additional Mg{sup 2+} binding site in the E. faecalis structure. In this report, they discuss the functional significance of Mg{sup 2+} binding sites in the cytosolic domains of MgtE transporters.

  13. The opportunistic pathogen Enterococcus faecalis resists phagosome acidification and autophagy to promote intracellular survival in macrophages.

    PubMed

    Zou, Jun; Shankar, Nathan

    2016-06-01

    While many strains of Enterococcus faecalis have been reported to be capable of surviving within macrophages for extended periods, the exact mechanisms involved are largely unknown. In this study, we found that after phagocytosis by macrophages, enterococci-containing vacuoles resist acidification, and E. faecalis is resistant to low pH. Ultrastructural examination of the enterococci-containing vacuole by transmission electron microscopy revealed a single membrane envelope, with no evidence of the classical double-membraned autophagosomes. Western blot analysis further confirmed that E. faecalis could trigger inhibition of the production of LC3-II during infection. By employing cells transfected with RFP-LC3 plasmid and infected with GFP-labelled E. faecalis, we also observed that E. faecalis was not delivered into autophagosomes during macrophage infection. While these observations indicated no role for autophagy in elimination of intracellular E. faecalis, enhanced production of reactive oxygen species and nitric oxide were keys to this process. Stimulation of autophagy suppressed the intracellular survival of E. faecalis in macrophages in vitro and decreased the burden of E. faecalis in vivo. In summary, the results from this study offer new insights into the interaction of E. faecalis with host cells and may provide a new approach to treatment of enterococcal infections.

  14. Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products.

    PubMed

    Pieniz, S; Andreazza, R; Okeke, B C; Camargo, F A O; Brandelli, A

    2015-11-10

    AbstractLactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faeciumspecies. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS•+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.

  15. Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products.

    PubMed

    Pieniz, S; Andreazza, R; Okeke, B C; Camargo, F A O; Brandelli, A

    2015-11-01

    Lactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faecium species. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS•+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.

  16. The anti-Candida activity by Ancillary Proteins of an Enterococcus faecium strain

    PubMed Central

    Roy, Utpal; Chalasani, Ajay G.; Shekh, M. Raeesh

    2015-01-01

    An antimycotic activity toward seven strains of Candida albicans was demonstrated erstwhile by a wild-type Enterococcus faecium isolated from a penguin rookery of the Antarctic region. In the present study the antimicrobial principle was purified by ion exchange and gel permeation chromatography and further was analyzed by LC-ESI-MS/MS. In the purification steps, the dialyzed concentrate and ion exchange fractions inhibited C. albicans MTCC 3958, 183, and SC 5314. However, the gel filtration purified fractions inhibited MTCC 3958 and 183. The data obtained from the LC-ESI-MS/MS indicate that the antimicrobial activity of the anti-Candida protein produced by E. faecium is facilitated by Sag A/Bb for the binding of the indicator organism's cell membrane. Partial N-terminal sequence revealed 12 N-terminal amino acid residues and its analysis shown that it belongs to the LysM motif. The nucleotide sequence of PCR-amplified product could detect 574 nucleotides of the LysM gene responsible for binding to chitin of the cell wall of Candida sp. PMID:26005434

  17. In vitro probiotic profiling of novel Enterococcus faecium and Leuconostoc mesenteroides from Tunisian freshwater fishes.

    PubMed

    El-Jeni, Rim; El Bour, Monia; Calo-Mata, Pilar; Böhme, Karola; Fernández-No, Inmaculada C; Barros-Velázquez, Jorge; Bouhaouala-Zahar, Balkiss

    2016-01-01

    Novel lactic acid bacteria isolated from different organs of freshwater fish were examined for their potential application as probiotics in raw and processed foods. Four isolates of Enterococcus faecium and Leuconostoc mesenteroides were identified at the molecular level by 16S rRNA sequencing and random amplification of polymorphic DNA - polymerase chain reaction, and their antimicrobial activity against a panel of pathogens and food-poisoning bacteria was investigated. The whole bacteriocins of the 4 isolates were characterized by enterobacterial repetitive intergenic consensus sequences in PCR. The isolates exhibited high inhibitory activities against food-borne pathogens and spoilage microbial species and have significant probiotic profiles, since they survived at pH 3.0 and in the presence of bile salts, pancreatin, and pepsin, without any detectable hemolytic activity. Further, moderate heat resistance, adhesion ability to steel surfaces, and sensitivity to clinically relevant antimicrobial agents were revealed for all the isolates. These results highlight the specific probiotic properties of the strains and give evidence for potential application in minimally processed foods subjected to moderate heat processing.

  18. Characterization and Application of Enterocin RM6, a Bacteriocin from Enterococcus faecalis

    PubMed Central

    Chung, Yoon-Kyung; Yousef, Ahmed E.

    2013-01-01

    Use of bacteriocins in food preservation has received great attention in recent years. The goal of this study is to characterize enterocin RM6 from Enterococcus faecalis OSY-RM6 and investigate its efficacy against Listeria monocytogenes in cottage cheese. Enterocin RM6 was purified from E. faecalis culture supernatant using ion exchange column, multiple C18-silica cartridges, followed by reverse-phase high-performance liquid chromatography. The molecular weight of enterocin RM6 is 7145.0823 as determined by mass spectrometry (MS). Tandem mass spectrometry (MS/MS) analysis revealed that enterocin RM6 is a 70-residue cyclic peptide with a head-to-tail linkage between methionine and tryptophan residues. The peptide sequence of enterocin RM6 was further confirmed by sequencing the structural gene of the peptide. Enterocin RM6 is active against Gram-positive bacteria, including L. monocytogenes, Bacillus cereus, and methicillin-resistant Staphylococcus aureus (MRSA). Enterocin RM6 (final concentration in cottage cheese, 80 AU/mL) caused a 4-log reduction in population of L. monocytogenes inoculated in cottage cheese within 30 min of treatment. Therefore, enterocin RM6 has potential applications as a potent antimicrobial peptide against foodborne pathogens in food. PMID:23844357

  19. The Enterococcal Surface Protein, Esp, Is Involved in Enterococcus faecalis Biofilm Formation

    PubMed Central

    Toledo-Arana, Alejandro; Valle, Jaione; Solano, Cristina; Arrizubieta, María Jesús; Cucarella, Carme; Lamata, Marta; Amorena, Beatriz; Leiva, José; Penadés, José Rafael; Lasa, Iñigo

    2001-01-01

    The enterococcal surface protein, Esp, is a high-molecular-weight surface protein of unknown function whose frequency is significantly increased among infection-derived Enterococcus faecalis isolates. In this work, a global structural similarity was found between Bap, a biofilm-associated protein of Staphylococcus aureus, and Esp. Analysis of the relationship between the presence of the Esp-encoding gene (esp) and the biofilm formation capacity in E. faecalis demonstrated that the presence of the esp gene is highly associated (P < 0.0001) with the capacity of E. faecalis to form a biofilm on a polystyrene surface, since 93.5% of the E. faecalis esp-positive isolates were capable of forming a biofilm. Moreover, none of the E. faecalis esp-deficient isolates were biofilm producers. Depending on the E. faecalis isolate, insertional mutagenesis of esp caused either a complete loss of the biofilm formation phenotype or no apparent phenotypic defect. Complementation studies revealed that Esp expression in an E. faecalis esp-deficient strain promoted primary attachment and biofilm formation on polystyrene and polyvinyl chloride plastic from urine collection bags. Together, these results demonstrate that (i) biofilm formation capacity is widespread among clinical E. faecalis isolates, (ii) the biofilm formation capacity is restricted to the E. faecalis strains harboring esp, and (iii) Esp promotes primary attachment and biofilm formation of E. faecalis on abiotic surfaces. PMID:11571153

  20. Characterization of vancomycin-resistant Enterococcus faecium isolated from swine in three Michigan counties.

    PubMed

    Donabedian, Susan M; Perri, Mary Beth; Abdujamilova, Nodira; Gordoncillo, Mary Joy; Naqvi, Amir; Reyes, Katherine C; Zervos, Marcus J; Bartlett, Paul

    2010-11-01

    Vancomycin-resistant enterococci are a major cause of nosocomial infections but are rarely found in humans in the community and have not been identified in food animals in the United States. We evaluated a total of 360 fecal specimens from humans and their animals being raised for exhibit at three county fairs in Michigan. Fecal samples from 158 humans, 55 swine, 50 cattle, 25 horses, 57 sheep, 14 goats, and 1 llama were obtained and plated onto Enterococcosel agar containing 16 μg/ml of vancomycin. Vancomycin-resistant Enterococcus faecium (VREF) was isolated from six pigs but not from humans or any animal other than pigs. All six VREF isolates had a MIC to vancomycin of ≥256 μg/ml and contained the vanA gene. Pulsed-field gel electrophoresis (PFGE) patterns of the six VREF isolates were ≥80% similar. Multilocus sequence typing (MLST) revealed sequence type 5 (ST5) (n = 2), ST6 (n = 3), and ST185 (n = 1), which are E. faecium sequence types belonging to clonal complex 5 (CC5). These findings show the dissemination of VREF strains among pigs in three Michigan counties. This is the first report of VRE found in food animals in the United States.

  1. Transcriptomic and functional analysis of NaCl-induced stress in Enterococcus faecalis.

    PubMed

    Solheim, Margrete; La Rosa, Sabina Leanti; Mathisen, Thomas; Snipen, Lars G; Nes, Ingolf F; Brede, Dag Anders

    2014-01-01

    The robust physiology of Enterococcus faecalis facilitates tolerance to various stresses. We here report the transcriptional response of E. faecalis V583 to growth in the presence of 6.5% NaCl. Among the early responses observed was an immediate down-regulation of mscL, accompanied by an up-regulation of genes predicted to be involved in uptake of extracellular potassium and glycine betaine. The high NaCl concentration also induced expression of chaperons and cell envelope related traits, such as the enterococcal polysaccharide antigen (epa) locus. Functional genetic analysis revealed reduced salt stress resistance in both epaB and epaE mutants. The reduced salt resistance phenotype associated with the epaB mutant was restored by complementation, hence demonstrating a role of Epa in the physiological robustness of E. faecalis. Furthermore, we demonstrate that Epa confers increased resistance towards multiple cell envelope stress-inducing factors. Accordingly, these findings delineate a potential link between the robust nature of E. faecalis and its ability to perform as a human pathogen, and provide a new perspective on the mechanisms by which Epa contributes to virulence. Notably, the high NaCl concentration also resulted in strict repression of the gelE-sprE operon and impaired gelatinase activity. We demonstrate that NaCl antagonize the GBAP-pheromone dependent induction in a concentration dependent manner.

  2. Implication of hypR in the virulence and oxidative stress response of Enterococcus faecalis.

    PubMed

    Verneuil, Nicolas; Rincé, Alain; Sanguinetti, Maurizio; Auffray, Yanick; Hartke, Axel; Giard, Jean-Christophe

    2005-11-01

    HypR has recently been described as the first transcriptional regulator involved in the oxidative stress response and in the intracellular survival of Enterococcus faecalis within macrophages. In order to characterize the HypR regulon, real-time quantitative RT-PCR experiments were performed. The expression of four genes involved in the oxidative stress response encoding catalase, glutathione reductase, and the two subunits of alkyl hydroperoxide reductase were down regulated in the hypR background under H(2)O(2) condition. These findings show that HypR acts as a transcriptional activator, especially during oxidative stress. In addition, DNAse I footprinting assays allowed us to identify the HypR-protected DNA regions corresponding to the "HypR box" in the hypR promoter. Moreover, the effect of the hypR mutation on the virulence of E. faecalis was evaluated in comparison with the wild-type JH2-2 strain using a mouse peritonitis model. Our results revealed that HypR appears to be an important virulence factor in E. faecalis.

  3. Crystal structure of an aerobic FMN-dependent azoreductase (AzoA) from Enterococcus faecalis.

    PubMed

    Liu, Zhi-Jie; Chen, Huizhong; Shaw, Neil; Hopper, Sherryll L; Chen, Lirong; Chen, Siwei; Cerniglia, Carl E; Wang, Bi-Cheng

    2007-07-01

    The initial critical step of reduction of the azo bond during the metabolism of azo dyes is catalyzed by a group of NAD(P)H dependant enzymes called azoreductases. Although several azoreductases have been identified from microorganisms and partially characterized, very little is known about the structural basis for substrate specificity and the nature of catalysis. Enterococcus faecalis azoreductase A (AzoA) is a highly active azoreductase with a broad spectrum of substrate specificity and is capable of degrading a wide variety of azo dyes. Here, we report the crystal structure of the AzoA from E. faecalis determined at 2.07 A resolution with bound FMN ligand. Phases were obtained by single wavelength anomalous scattering of selenomethionine labeled protein crystals. The asymmetric unit consisted of two dimers with one FMN molecule bound to each monomer. The AzoA monomer takes a typical NAD(P)-binding Rossmann fold with a highly conserved FMN binding pocket. A salt bridge between Arg18 and Asp184 restricts the size of the flavin binding pocket such that only FMN can bind. A putative NADH binding site could be identified and a plausible mechanism for substrate reduction is proposed. Expression studies revealed azoA gene to be expressed constitutively in E. faecalis.

  4. TLR-7 activation enhances IL-22-mediated colonization resistance against vancomycin-resistant enterococcus.

    PubMed

    Abt, Michael C; Buffie, Charlie G; Sušac, Bože; Becattini, Simone; Carter, Rebecca A; Leiner, Ingrid; Keith, James W; Artis, David; Osborne, Lisa C; Pamer, Eric G

    2016-02-24

    Antibiotic administration can disrupt the intestinal microbiota and down-regulate innate immune defenses, compromising colonization resistance against orally acquired bacterial pathogens. Vancomycin-resistant Enterococcus faecium (VRE), a major cause of antibiotic-resistant infections in hospitalized patients, thrives in the intestine when colonization resistance is compromised, achieving extremely high densities that can lead to bloodstream invasion and sepsis. Viral infections, by mechanisms that remain incompletely defined, can stimulate resistance against invading bacterial pathogens. We report that murine norovirus infection correlates with reduced density of VRE in the intestinal tract of mice with antibiotic-induced loss of colonization resistance. Resiquimod (R848), a synthetic ligand for Toll-like receptor 7 (TLR-7) that stimulates antiviral innate immune defenses, restores expression of the antimicrobial peptide Reg3γ and reestablishes colonization resistance against VRE in antibiotic-treated mice. Orally administered R848 triggers TLR-7 on CD11c(+) dendritic cells, inducing interleukin-23 (IL-23) expression followed by a burst of IL-22 secretion by innate lymphoid cells, leading to Reg3γ expression and restoration of colonization resistance against VRE. Our findings reveal that an orally bioavailable TLR-7 ligand that stimulates innate antiviral immune pathways in the intestine restores colonization resistance against a highly antibiotic-resistant bacterial pathogen.

  5. A Discrete Events Delay Differential System Model for Transmission of Vancomycin-Resistant Enterococcus (VRE) in Hospitals

    DTIC Science & Technology

    2010-09-19

    A Discrete Events Delay Differential System Model for Transmission of Vancomycin-Resistant Enterococcus (VRE) in Hospitals A. R. Ortiz1, H. T. Banks2...Model for Transmission of Vancomycin-Resistant Enterococcus (VRE) in Hospitals 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...hospital unit on Vancomycin-resistant Enterococcus (VRE), one of the most prevalent and dangerous pathogens involved in hospital infections, is used to

  6. Identification and characterization of gsp65, an organic hydroperoxide resistance (ohr) gene encoding a general stress protein in Enterococcus faecalis.

    PubMed

    Rincé, A; Giard, J C; Pichereau, V; Flahaut, S; Auffray, Y

    2001-02-01

    The Enterococcus faecalis general stress protein Gsp65 has been purified from two-dimensional gel electrophoresis. Determination of its N-terminal sequence and characterization of the corresponding gene revealed that the gsp65 product is a 133-amino-acid protein sharing homologies with organic hydroperoxide resistance (Ohr) proteins. Transcriptional analysis of gsp65 gave evidence for a monocistronic mRNA initiated 52 nucleotides upstream of the ATG start codon and for an induction in response to hydrogen peroxide, heat shock, acid pH, detergents, ethanol, sodium chloride, and tert-butylhydroperoxide (tBOOH). A gsp65 mutant showed increased sensitivity to the organic hydroperoxide tBOOH and to ethanol.

  7. Molecular characterization and antibiotic resistance of Enterococcus species from gut microbiota of Chilean Altiplano camelids

    PubMed Central

    Guerrero-Olmos, Katheryne; Báez, John; Valenzuela, Nicomédes; Gahona, Joselyne; del Campo, Rosa; Silva, Juan

    2014-01-01

    Background Enterococcus is one of the major human pathogens able to acquire multiple antibiotic-resistant markers as well as virulence factors which also colonize remote ecosystems, including wild animals. In this work, we characterized the Enterococcus population colonizing the gut of Chilean Altiplano camelids without foreign human contact. Material and methods Rectal swabs from 40 llamas and 10 alpacas were seeded in M-Enterococcus agar, and we selected a total of 57 isolates. Species identification was performed by biochemical classical tests, semi-automated WIDER system, mass spectrometry analysis by MALDI-TOF (matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer), and, finally, nucleotide sequence of internal fragments of the 16S rRNA, rpoB, pheS, and aac(6)-I genes. Genetic diversity was measured by pulsed field gel electrophoresis (PFGE)-SmaI, whereas the antibiotic susceptibility was determined by the WIDER system. Carriage of virulence factors was explored by polymerase chain reaction (PCR). Results Our results demonstrated that the most prevalent specie was Enterococcus hirae (82%), followed by other non–Enterococcus faecalis and non–Enterococcus faecium species. Some discrepancies were detected among the identification methods used, and the most reliable were the rpoB, pheS, and aac(6)-I nucleotide sequencing. Selected isolates exhibited susceptibility to almost all studied antibiotics, and virulence factors were not detected by PCR. Finally, some predominant clones were characterized by PFGE into a diverse genetic background. Conclusion Enterococcus species from the Chilean camelids’ gut microbiota were different from those adapted to humans, and they remained free of antibiotic resistance mechanisms as well as virulence factors. PMID:25405007

  8. Enterococcus phages as potential tool for identifying sewage inputs in the Great Lakes region

    USGS Publications Warehouse

    ,; K.Vijayavel,; Byappanahalli, Muruleedhara N.; J. Ebdon,; ,; H. Taylor,; ,; Whitman, Richard L.; ,; D.R. Kashian,

    2014-01-01

    Bacteriophages are viruses living in bacteria that can be used as a tool to detect fecal contamination in surface waters around the world. However, the lack of a universal host strain makes them unsuitable for tracking fecal sources. We evaluated the suitability of two newly isolated Enterococcus host strains (ENT-49 and ENT-55) capable for identifying sewage contamination in impacted waters by targeting phages specific to these hosts. Both host strains were isolated from wastewater samples and identified as E. faecium by 16S rRNA gene sequencing. Occurrence of Enterococcus phages was evaluated in sewage samples (n = 15) from five wastewater treatment plants and in fecal samples from twenty-two species of wild and domesticated animals (individual samples; n = 22). Levels of Enterococcus phages, F + coliphages, Escherichia coli and enterococci were examined from four rivers, four beaches, and three harbors. Enterococcus phages enumeration was at similar levels (Mean = 6.72 Log PFU/100 mL) to F + coliphages in all wastewater samples, but were absent from all non-human fecal sources tested. The phages infecting Enterococcus spp. and F + coliphages were not detected in the river samples (detection threshold < 10 PFU/100 mL), but were present in the beach and harbor samples (range = 1.83 to 2.86 Log PFU/100 mL). Slightly higher concentrations (range = 3.22 to 3.69 Log MPN/100 mL) of E. coli and enterococci when compared to F + coliphages and Enterococcus phages, were observed in the river, beach and harbor samples. Our findings suggest that the bacteriophages associated with these particular Enterococcus host strains offer potentially sensitive and human-source specific indicators of enteric pathogen risk.

  9. Phage therapy against Enterococcus faecalis in dental root canals

    PubMed Central

    Khalifa, Leron; Shlezinger, Mor; Beyth, Shaul; Houri-Haddad, Yael; Coppenhagen-Glazer, Shunit; Beyth, Nurit; Hazan, Ronen

    2016-01-01

    Antibiotic resistance is an ever-growing problem faced by all major sectors of health care, including dentistry. Recurrent infections related to multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, and vancomycin-resistant enterococci (VRE) in hospitals are untreatable and question the effectiveness of notable drugs. Two major reasons for these recurrent infections are acquired antibiotic resistance genes and biofilm formation. None of the traditionally known effective techniques have been able to efficiently resolve these issues. Hence, development of a highly effective antibacterial practice has become inevitable. One example of a hard-to-eradicate pathogen in dentistry is Enterococcus faecalis, which is one of the most common threats observed in recurrent root canal treatment failures, of which the most problematic to treat are its biofilm-forming VRE strains. An effective response against such infections could be the use of bacteriophages (phages). Phage therapy was found to be highly effective against biofilm and multidrug-resistant bacteria and has other advantages like ease of isolation and possibilities for genetic manipulations. The potential of phage therapy in dentistry, in particular against E. faecalis biofilms in root canals, is almost unexplored. Here we review the efforts to develop phage therapy against biofilms. We also focus on the phages isolated against E. faecalis and discuss the possibility of using phages against E. faecalis biofilm in root canals. PMID:27640530

  10. Characterization of Class IIa Bacteriocin Resistance in Enterococcus faecium.

    PubMed

    Geldart, Kathryn; Kaznessis, Yiannis N

    2017-04-01

    Vancomycin-resistant enterococci, particularly resistant Enterococcus faecium, pose an escalating threat in nosocomial environments because of their innate resistance to many antibiotics, including vancomycin, a treatment of last resort. Many class IIa bacteriocins strongly target these enterococci and may offer a potential alternative for the management of this pathogen. However, E. faecium's resistance to these peptides remains relatively uncharacterized. Here, we explored the development of resistance of E. faecium to a cocktail of three class IIa bacteriocins: enterocin A, enterocin P, and hiracin JM79. We started by quantifying the frequency of resistance to these peptides in four clinical isolates of E. faecium We then investigated the levels of resistance of E. faecium 6E6 mutants as well as their fitness in different carbon sources. In order to elucidate the mechanism of resistance of E. faecium to class IIa bacteriocins, we completed whole-genome sequencing of resistant mutants and performed reverse transcription-quantitative PCR (qRT-PCR) of a suspected target mannose phosphotransferase (ManPTS). We then verified this ManPTS's role in bacteriocin susceptibility by showing that expression of the ManPTS in Lactococcus lactis results in susceptibility to the peptide cocktail. Based on the evidence found from these studies, we conclude that, in accord with other studies in E. faecalis and Listeria monocytogenes, resistance to class IIa bacteriocins in E. faecium 6E6 is likely caused by the disruption of a particular ManPTS, which we believe we have identified.

  11. Probiotic potential of Enterococcus faecalis strains isolated from meconium

    PubMed Central

    Al Atya, Ahmed K.; Drider-Hadiouche, Karima; Ravallec, Rozenn; Silvain, Amadine; Vachee, Anne; Drider, Djamel

    2015-01-01

    107 bacterial isolates with Gram positive staining and negative catalase activity, presumably assumed as lactic acid bacteria, were isolated from samples of meconium of 6 donors at Roubaix hospital, in the north of France. All these bacterial isolates were identified by MALDI-TOF mass spectrometry as Enterococcus faecalis. However, only six isolates among which E. faecalis 14, E. faecalis 28, E. faecalis 90, E. faecalis 97, and E. faecalis 101 (obtained from donor 3), and E. faecalis 93 (obtained from donor 5) were active against some Gram-negative bacteria and Gram-positive bacteria , through production of lactic acid, and bacteriocin like inhibitory substances. The identification of these isolates was confirmed by 16rDNA sequencing and their genetic relatedness was established by REP-PCR and pulsed field gel electrophoresis methods. Importantly, the aforementioned antagonistic isolates were sensitive to various classes of antibiotics tested, exhibited high scores of coaggregation and hydrophobicity, and were not hemolytic. Taken together, these properties render these strains as potential candidates for probiotic applications. PMID:25883590

  12. Rapid Kill—Novel Endodontic Sealer and Enterococcus faecalis

    PubMed Central

    Zaltsman, Nathan; Houri-Haddad, Yael; Abramovitz, Itzhak; Davidi, Michael Perez; Weiss, Ervin I.

    2013-01-01

    With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means. PMID:24223159

  13. Susceptibilties of two Enterococcus faecalis phenotypes to root canal medications.

    PubMed

    Abdullah, Mariam; Ng, Yuan-Ling; Gulabivala, Kishor; Moles, David R; Spratt, David A

    2005-01-01

    This study aimed to investigate and compare the efficacy of selected root canal irrigants and a medicament on a clinical isolate of Enterococcus faecalis grown as biofilm or planktonic suspension phenotype. A cell-dense pellet "presentation" prepared from planktonic phenotype was also tested. Each bacterial presentation was exposed to calcium hydroxide (pH 12.3), 0.2% chlorhexidine gluconate, 17% ethylene-diamine-tetra-acetic acid, 10% povidone iodine, or 3.0% sodium hypochlorite (NaOCl) for a range of time periods (1, 2, 4, 8, 15, 30, and 60 min). Phosphate buffered saline was used as a control agent. The difference in gradients of bacterial killing among the biofilm, planktonic suspension or pellet presentation was significant (p < 0.05) and dependent upon the test agent except in the case of NaOCl and calcium hydroxide where no difference could be detected. NaOCl was the most effective agent and achieved 100% kills for all presentations of E. faecalis after a 2 min contact time.

  14. Mechanisms of clinical resistance to fluoroquinolones in Enterococcus faecalis.

    PubMed Central

    Nakanishi, N; Yoshida, S; Wakebe, H; Inoue, M; Mitsuhashi, S

    1991-01-01

    About 10% of 100 clinical isolates of Enterococcus faecalis were resistant to greater than or equal to 25 micrograms of norfloxacin, ofloxacin, ciprofloxacin, and temafloxacin per ml. In this study, the DNA gyrase of E. faecalis was purified from a fluoroquinolone-susceptible strain (ATCC 19433) and two resistant isolates, MS16968 and MS16996. Strains MS16968 and MS16996 were 64- to 128-fold and 16- to 32-fold less susceptible, respectively, to fluoroquinolones than was ATCC 19433; MICs of nonquinolone antibacterial agents for these strains were almost equal. The DNA gyrase from ATCC 19433 had two subunits, designated A and B, with properties similar to those of DNA gyrase from other gram-positive bacteria such as Bacillus subtilis and Micrococcus luteus. Inhibition of the supercoiling activity of the enzyme from ATCC 19433 by the fluoroquinolones correlated with their antibacterial activities. In contrast, preparations of DNA gyrase from MS16968 and MS16996 were at least 30-fold less sensitive to inhibition of supercoiling by the fluoroquinolones than the gyrase from ATCC 19433 was. Experiments that combined heterologous gyrase subunits showed that the A subunit from either of the resistant isolates conferred resistance to fluoroquinolones. These findings indicate that an alteration in the gyrase A subunit is the major contributor to fluoroquinolone resistance in E. faecalis clinical isolates. A difference in drug uptake may also contribute to the level of fluoroquinolone resistance in these isolates. Images PMID:1656852

  15. Enterococcal surface protein, Esp, enhances biofilm formation by Enterococcus faecalis.

    PubMed

    Tendolkar, Preeti M; Baghdayan, Arto S; Gilmore, Michael S; Shankar, Nathan

    2004-10-01

    Enterococci play a dual role in human ecology. They serve as commensal organisms of the gastrointestinal tract and are also leading causes of multiple antibiotic-resistant hospital-acquired infection. Many nosocomial infections result from the ability of microorganisms to form biofilms. The molecular mechanisms involved in enterococcal biofilm formation are only now beginning to be understood. Enterococcal surface protein, Esp, has been reported to contribute to biofilm formation by Enterococcus faecalis. Recent studies have shown that enterococci form biofilms independently of Esp expression. To precisely determine what role Esp plays in E. faecalis biofilm formation, Esp was expressed on the cell surface of genetically well-defined, natively Esp-deficient strains, and isogenic Esp-positive and Esp-deficient strains were compared for their biofilm-forming ability. The results show that Esp expression leads to a significant increase in biofilm formation, irrespective of the strain tested. The contribution of Esp to biofilm formation was found to be most pronounced in the presence of 0.5% (wt/vol) or greater glucose. These results unambiguously define Esp as a key contributor to the ability of E. faecalis to form biofilms.

  16. Enterococcus faecalis promotes osteoclastogenesis and semaphorin 4D expression.

    PubMed

    Wang, Shuai; Deng, Zuhui; Seneviratne, Chaminda J; Cheung, Gary S P; Jin, Lijian; Zhao, Baohong; Zhang, Chengfei

    2015-10-01

    Enterococcus faecalis is considered a major bacterial pathogen implicated in endodontic infections and contributes considerably to periapical periodontitis. This study aimed to investigate the potential mechanisms by which E. faecalis accounts for the bone destruction in periapical periodontitis in vitro. Osteoclast precursor RAW264.7 cells were treated with E. faecalis ATCC 29212 and a wild strain of E. faecalis derived clinically from an infected root canal. The results showed that, to some extent, E. faecalis induced the RAW264.7 cells to form tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclast-like cells. This pathogen markedly stimulated RAW264.7 cells to express semaphorin 4D (Sema4D), which inhibits bone formation. Once RAW264.7 cells were primed by low-dose receptor activator of nuclear factor-kappa B ligand (RANKL), E. faecalis could significantly increase the production of TRAP-positive multinucleated cells and up-regulate the expression of osteoclast-specific markers, including NFATc1, TRAP and cathepsin K. Both p38 and ERK1/2 MAPK signaling pathways were activated by E. faecalis in RANKL-primed RAW264.7 cells, and meanwhile the expression of Sema4D was highly increased. In conclusion, E. faecalis may greatly contribute to the bone resorption in periapical periodontitis by promoting RANKL-dependent osteoclastogenesis and expression of Sema4D through activation of p38 and ERK1/2 MAPK signaling pathways.

  17. Pulmonary Hypertension Syndrome in Broilers Caused by Enterococcus faecalis†

    PubMed Central

    Tankson, J. D.; Thaxton, J. P.; Vizzier-Thaxton, Y.

    2001-01-01

    A field strain of Enterococcus faecalis was administered to broiler chicks at doses of 0, 3 × 106, 1.5 × 107, and 2 × 107 bacteria/bird either intra-abdominally or intravenously. In trials 1 to 3, birds were reared communally in a broiler house on pine shaving litter. In trial 4, challenged and control birds were maintained in separate isolation rooms in metal cages with raised wire floors. Challenged birds exhibited a characteristic cavity or depression in the external wall of the right ventricle. A subjective scoring system was devised to quantify challenge effects by assigning each heart a score of 1 to 4. The average number of birds, over all trials and over all dose levels, exhibiting the ventricular cavity was 93%. This value in controls was 5%. The average heart score for challenged birds was 3.1, and that for controls was 0.20. Heart scores of challenged and control chicks were not different in birds reared communally or in separate isolation rooms. Additionally, both routes of administration were equally effective. Results suggest that challenge with E. faecalis caused pulmonary hypertension. PMID:11553576

  18. Pulmonary hypertension syndrome in broilers caused by Enterococcus faecalis.

    PubMed

    Tankson, J D; Thaxton, J P; Vizzier-Thaxton, Y

    2001-10-01

    A field strain of Enterococcus faecalis was administered to broiler chicks at doses of 0, 3 x 10(6), 1.5 x 10(7), and 2 x 10(7) bacteria/bird either intra-abdominally or intravenously. In trials 1 to 3, birds were reared communally in a broiler house on pine shaving litter. In trial 4, challenged and control birds were maintained in separate isolation rooms in metal cages with raised wire floors. Challenged birds exhibited a characteristic cavity or depression in the external wall of the right ventricle. A subjective scoring system was devised to quantify challenge effects by assigning each heart a score of 1 to 4. The average number of birds, over all trials and over all dose levels, exhibiting the ventricular cavity was 93%. This value in controls was 5%. The average heart score for challenged birds was 3.1, and that for controls was 0.20. Heart scores of challenged and control chicks were not different in birds reared communally or in separate isolation rooms. Additionally, both routes of administration were equally effective. Results suggest that challenge with E. faecalis caused pulmonary hypertension.

  19. Modeling the growth of Enterococcus faecium in bologna sausage.

    PubMed Central

    Zanoni, B; Garzaroli, C; Anselmi, S; Rondinini, G

    1993-01-01

    A study to set up mathematical models which allow the prediction of Enterococcus faecium growth in bologna sausage (mortadella) was carried out. Growth curves were obtained at different temperatures (5, 6, 12, 15, 25, 32, 35, 37, 42, 46, 50, 52, and 55 degrees C). The Gompertz and logistic models, modified by Zwietering, were found to fit with the representation of experimental curves. The variations of the parameters A (i.e., the asymptotic value reached by the relative population during the stationary growth phase), mu m (i.e., the maximum specific growth rate during the exponential growth phase), and lambda (i.e., the lag time) with temperature were then modeled. The variation of A with temperature can be described by an empirical polynomial model, whereas the variation of mu m and lambda can be described by the Ratkowsky model modified by Zwietering and the Adair model, respectively. Data processing of these models has shown that the minimum growth temperature for E. faecium is 0.1 degrees C, the maximum growth temperature is 53.4 degrees C, and the optimal growth temperature is 42 to 45 degrees C. PMID:8250562

  20. Antimicrobial effect of alexidine and chlorhexidine against Enterococcus faecalis infection

    PubMed Central

    Kim, Hyun-Shik; Woo Chang, Seok; Baek, Seung-Ho; Han, Seung Hyun; Lee, Yoon; Zhu, Qiang; Kum, Kee-Yeon

    2013-01-01

    A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine. The aim of this study was to compare the antimicrobial activity of 1% alexidine with that of 2% chlorhexidine using Enterococcus faecalis-infected dentin blocks. Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each. E. faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2% chlorhexidine or 1% alexidine solutions for 5 and 10 min, respectively. Sterile saline was used as a control. The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope. Significantly fewer bacteria were observed in the 2% chlorhexidine- or 1% alexidine-soaked groups than in the control group (P<0.05). However, there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups (P>0.05). Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups. In conclusion, 10-min soaking with 1% alexidine or 2% chlorhexidine can be effective against E. faecalis infection. PMID:23492900

  1. Phage therapy against Enterococcus faecalis in dental root canals.

    PubMed

    Khalifa, Leron; Shlezinger, Mor; Beyth, Shaul; Houri-Haddad, Yael; Coppenhagen-Glazer, Shunit; Beyth, Nurit; Hazan, Ronen

    2016-01-01

    Antibiotic resistance is an ever-growing problem faced by all major sectors of health care, including dentistry. Recurrent infections related to multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, and vancomycin-resistant enterococci (VRE) in hospitals are untreatable and question the effectiveness of notable drugs. Two major reasons for these recurrent infections are acquired antibiotic resistance genes and biofilm formation. None of the traditionally known effective techniques have been able to efficiently resolve these issues. Hence, development of a highly effective antibacterial practice has become inevitable. One example of a hard-to-eradicate pathogen in dentistry is Enterococcus faecalis, which is one of the most common threats observed in recurrent root canal treatment failures, of which the most problematic to treat are its biofilm-forming VRE strains. An effective response against such infections could be the use of bacteriophages (phages). Phage therapy was found to be highly effective against biofilm and multidrug-resistant bacteria and has other advantages like ease of isolation and possibilities for genetic manipulations. The potential of phage therapy in dentistry, in particular against E. faecalis biofilms in root canals, is almost unexplored. Here we review the efforts to develop phage therapy against biofilms. We also focus on the phages isolated against E. faecalis and discuss the possibility of using phages against E. faecalis biofilm in root canals.

  2. Enterococcus growth on eelgrass (Zostera marina); implications for water quality.

    PubMed

    Ferguson, Donna M; Weisberg, Stephen B; Hagedorn, Charles; De Leon, Kristine; Mofidi, Vida; Wolfe, Julia; Zimmerman, May; Jay, Jennifer A

    2016-04-01

    Enterococci are fecal indicator bacteria used to monitor fecal pollution of recreational waters. When enterococci levels exceed health standards, fecal pollution is assumed as the cause. Enterococci growing on plants limit their usefulness as fecal indicator bacteria. Here we examined enterococcal growth on eelgrass in Mission Bay, CA where enterococci levels have exceeded water quality thresholds. A total of 69 eelgrass samples were collected from six sites, shaken to remove enterococci attached to plant surfaces and the eluant filtered onto culture media. Isolates were then identified to species using biochemical methods, and DNA typing by pulsed-field gel electrophoresis was done to assess clonality of strains. Enterococci concentrations among eelgrass ranged from 8 to 14 000 CFU g(-1) dry weight. The most predominant enterococcal species found were Enterococcus casseliflavus and E. hirae followed by E. faecalis. Cluster analysis indicated a high level of clonality among isolates across all species, with clonal isolates consistently associated with individual eelgrass samples. Finding high densities of E. casseliflavus, E. hirae and E. faecalis on eelgrass that included clonal strains indicates the capability of enterococcal growth on eelgrass. Amplification of enterococci on eelgrass presents challenges for regulatory agencies that interpret elevated levels of these bacteria as an indication of fecal pollution.

  3. Susceptibilities of Enterococcus faecalis biofilms to some antimicrobial medications.

    PubMed

    Lima, K C; Fava, L R; Siqueira, J F

    2001-10-01

    Enterococcus faecalis has been suggested to be an important etiological agent in endodontic failures. The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. One-day and three-day biofilms of E. faecalis were induced on cellulose nitrate membrane filters. Each biofilm-containing membrane was thoroughly covered with 1 ml of the test medications and incubated for 1 day at 37 degrees C. Treated biofilms were then aseptically transferred to vials containing a neutralizing agent in saline solution and vortexed. Suspensions were 10-fold diluted, seeded onto Mitis salivarius agar plates, and the colony-forming units counted after 48 h of incubation. There were significant differences between the formulations tested. The association of clindamycin with metronidazole significantly reduced the number of cells in 1-day biofilms. However of all medications tested, only 2% chlorhexidine-containing medications were able to thoroughly eliminate most of both 1-day and 3-day E. faecalis biofilms.

  4. Functional genomic analysis of bile salt resistance in Enterococcus faecium

    PubMed Central

    2013-01-01

    Background Enterococcus faecium is a Gram-positive commensal bacterium of the mammalian intestinal tract. In the last two decades it has also emerged as a multi-resistant nosocomial pathogen. In order to survive in and colonize the human intestinal tract E. faecium must resist the deleterious actions of bile. The molecular mechanisms exploited by this bacterium to tolerate bile are as yet unexplored. Results In this study we used a high-throughput quantitative screening approach of transposon mutant library, termed Microarray-based Transposon Mapping (M-TraM), to identify the genetic determinants required for resistance to bile salts in E. faecium E1162. The gene gltK, which is predicted to encode a glutamate/aspartate transport system permease protein, was identified by M-TraM to be involved in bile resistance. The role of GltK in bile salt resistance was confirmed by the subsequent observation that the deletion of gltK significantly sensitized E. faecium E1162 to bile salts. To further characterize the response of E. faecium E1162 to bile salts, we performed a transcriptome analysis to identify genes that are regulated by exposure to 0.02% bile salts. Exposure to bile salts resulted in major transcriptional rearrangements, predominantly in genes involved in carbohydrate, nucleotide and coenzyme transport and metabolism. Conclusion These findings add to a better understanding of the molecular mechanisms by which E. faecium responds and resists the antimicrobial action of bile salts. PMID:23641968

  5. The Capability of Tyramine Production and Correlation between Phenotypic and Genetic Characteristics of Enterococcus faecium and Enterococcus faecalis Strains.

    PubMed

    Bargossi, Eleonora; Gardini, Fausto; Gatto, Veronica; Montanari, Chiara; Torriani, Sandra; Tabanelli, Giulia

    2015-01-01

    The aim of this study was to investigate the diversity of tyramine production capability of four Enterococcus strains in buffered systems in relation to their genetic characteristics and environmental conditions. Cells of the strains Enterococcus faecalis EF37 and ATCC 29212, and E. faecium FC12 and FC643 were re-suspended in phosphate/citrate buffers with different pH, NaCl concentration and incubation temperature. At intervals, cell viability and tyramine production were assessed by plate counting and HPLC analysis, respectively. The activity of a purified tyrosine decarboxylase (TDC) was determined under the same conditions, as a reference. Reduced loss in cell viability was observed in all the tested conditions, except for pH 4 after 24 h. The TDC activity was greatly heterogeneous within the enterococci: EF37 and FC12 produced the higher tyramine concentrations, ATCC 29212 showed a reduced decarboxylase activity, while EF643 did not accumulate detectable amounts of tyramine in all the conditions assayed. Among the considerate variables, temperature was the most influencing factor on tyramine accumulation for enterococcal cells. To further correlate the phenotypic and genetic characteristics of the enterococci, the TDC operon region carrying the genes tyrosine decarboxylase (tyrDC), tyrosine/tyramine permease (tyrP), and Na(+)/H(+) antiporter (nhaC-2) was amplified and sequenced. The genetic organization and nucleotide sequence of this operon region were highly conserved in the enterococcal strains of the same species. The heterogeneity in tyramine production found between the two E. faecalis strains could be ascribed to different regulation mechanisms not yet elucidated. On the contrary, a codon stop was identified in the translated tyrDC sequence of E. faecium FC643, supporting its inability to accumulate tyramine in the tested conditions. In addition, the presence of an additional putative tyrosine decarboxylase with different substrate specificity and

  6. The Capability of Tyramine Production and Correlation between Phenotypic and Genetic Characteristics of Enterococcus faecium and Enterococcus faecalis Strains

    PubMed Central

    Bargossi, Eleonora; Gardini, Fausto; Gatto, Veronica; Montanari, Chiara; Torriani, Sandra; Tabanelli, Giulia

    2015-01-01

    The aim of this study was to investigate the diversity of tyramine production capability of four Enterococcus strains in buffered systems in relation to their genetic characteristics and environmental conditions. Cells of the strains Enterococcus faecalis EF37 and ATCC 29212, and E. faecium FC12 and FC643 were re-suspended in phosphate/citrate buffers with different pH, NaCl concentration and incubation temperature. At intervals, cell viability and tyramine production were assessed by plate counting and HPLC analysis, respectively. The activity of a purified tyrosine decarboxylase (TDC) was determined under the same conditions, as a reference. Reduced loss in cell viability was observed in all the tested conditions, except for pH 4 after 24 h. The TDC activity was greatly heterogeneous within the enterococci: EF37 and FC12 produced the higher tyramine concentrations, ATCC 29212 showed a reduced decarboxylase activity, while EF643 did not accumulate detectable amounts of tyramine in all the conditions assayed. Among the considerate variables, temperature was the most influencing factor on tyramine accumulation for enterococcal cells. To further correlate the phenotypic and genetic characteristics of the enterococci, the TDC operon region carrying the genes tyrosine decarboxylase (tyrDC), tyrosine/tyramine permease (tyrP), and Na+/H+ antiporter (nhaC-2) was amplified and sequenced. The genetic organization and nucleotide sequence of this operon region were highly conserved in the enterococcal strains of the same species. The heterogeneity in tyramine production found between the two E. faecalis strains could be ascribed to different regulation mechanisms not yet elucidated. On the contrary, a codon stop was identified in the translated tyrDC sequence of E. faecium FC643, supporting its inability to accumulate tyramine in the tested conditions. In addition, the presence of an additional putative tyrosine decarboxylase with different substrate specificity and genetic

  7. The Heterodimeric ABC Transporter EfrCD Mediates Multidrug Efflux in Enterococcus faecalis

    PubMed Central

    Hürlimann, Lea M.; Corradi, Valentina; Hohl, Michael; Bloemberg, Guido V.; Tieleman, D. Peter

    2016-01-01

    Nosocomial infections with Enterococcus faecalis are an emerging health problem. However, drug efflux pumps contributing to intrinsic drug resistance are poorly studied in this Gram-positive pathogen. In this study, we functionally investigated seven heterodimeric ABC transporters of E. faecalis that are annotated as drug efflux pumps. Deletion of ef0789-ef0790 on the chromosome of E. faecalis resulted in increased susceptibility to daunorubicin, doxorubicin, ethidium, and Hoechst 33342, and the corresponding transporter was named EfrCD. Unexpectedly, the previously described heterodimeric multidrug ABC transporter EfrAB contributes marginally to drug efflux in the endogenous context of E. faecalis. In contrast, heterologous expression in Lactococcus lactis revealed that EfrAB, EfrCD, and the product of ef2226-ef2227 (EfrEF) mediate the efflux of fluorescent substrates and confer resistance to multiple dyes and drugs, including fluoroquinolones. Four of seven transporters failed to exhibit drug efflux activity for the set of drugs and dyes tested, even upon overexpression in L. lactis. Since all seven transporters were purified as heterodimers after overexpression in L. lactis, a lack of drug efflux activity is not attributed to poor expression or protein aggregation. Reconstitution of the purified multidrug transporters EfrAB, EfrCD, and EfrEF in proteoliposomes revealed functional coupling between ATP hydrolysis and drug binding. Our analysis creates an experimental basis for the accurate prediction of drug efflux transporters and indicates that many annotated multidrug efflux pumps might be incapable of drug transport and thus might fulfill other physiological functions in the cell. PMID:27381387

  8. Characterization of functional properties of Enterococcus faecium strains isolated from human gut.

    PubMed

    İspirli, Hümeyra; Demirbaş, Fatmanur; Dertli, Enes

    2015-11-01

    The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut- and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests.

  9. Chitosan-propolis nanoparticle formulation demonstrates anti-bacterial activity against Enterococcus faecalis biofilms.

    PubMed

    Ong, Teik Hwa; Chitra, Ebenezer; Ramamurthy, Srinivasan; Siddalingam, Rajinikanth Paruvathanahalli; Yuen, Kah Hay; Ambu, Stephen Periathamby; Davamani, Fabian

    2017-01-01

    Propolis obtained from bee hives is a natural substance with antimicrobial properties. It is limited by its insolubility in aqueous solutions; hence ethanol and ethyl acetate extracts of Malaysian propolis were prepared. Both the extracts displayed antimicrobial and anti-biofilm properties against Enterococcus faecalis, a common bacterium associated with hospital-acquired infections. High performance liquid chromatography (HPLC) analysis of propolis revealed the presence of flavonoids like kaempferol and pinocembrin. This study investigated the role of propolis developed into nanoparticles with chitosan for its antimicrobial and anti-biofilm properties against E. faecalis. Bacteria that grow in a slimy layer of biofilm are resistant to penetration by antibacterial agents. The use of nanoparticles in medicine has received attention recently due to better bioavailability, enhanced penetrative capacity and improved efficacy. A chitosan-propolis nanoformulation was chosen based on ideal physicochemical properties such as particle size, zeta potential, polydispersity index, encapsulation efficiency and the rate of release of the active ingredients. This formulation inhibited E. faecalis biofilm formation and reduced the number of bacteria in the biofilm by ~90% at 200 μg/ml concentration. When tested on pre-formed biofilms, the formulation reduced bacterial number in the biofilm by ~40% and ~75% at 200 and 300 μg/ml, respectively. The formulation not only reduced bacterial numbers, but also physically disrupted the biofilm structure as observed by scanning electron microscopy. Treatment of biofilms with chitosan-propolis nanoparticles altered the expression of biofilm-associated genes in E. faecalis. The results of this study revealed that chitosan-propolis nanoformulation can be deemed as a potential anti-biofilm agent in resisting infections involving biofilm formation like chronic wounds and surgical site infections.

  10. Diversity of plasmids and Tn1546-type transposons among VanA Enterococcus faecium in Poland.

    PubMed

    Wardal, E; Kuch, A; Gawryszewska, I; Żabicka, D; Hryniewicz, W; Sadowy, E

    2017-02-01

    The objective of this study was to investigate the antimicrobial resistance, Tn1546 transposon variability and plasmid diversity among Polish vancomycin-resistant Enterococcus faecium (VREfm) isolates of VanA phenotype in the context of their clonal structure. Two hundred sixteen clinical VREfm isolates collected between 1997 and 2010 were studied by antimicrobial susceptibility testing, MLST, MLVA and detection of IS16, esp Efm, pilA, intA and plasmid-specific genes by PCR. Tn1546 structure was revealed by overlapping PCR and sequencing. Selected isolates were subjected to PFGE-S1 and Southern hybridization analyses. The vast majority of the isolates (95.8 %) belonged to lineages 17/18 (during the whole study period 1997-2010) and 78 (mostly in 2006-2010) of hospital-adapted meroclone of E. faecium. All isolates displayed a multi-drug resistance phenotype. Twenty-eight Tn1546 types (including 26 novel ones) were associated with eight different ISs (IS1216, IS1251, ISEfa4, ISEfa5, ISEfm2, ISEf1, IS3-like, ISEfm1-like). The vanA-determinant was typically located on plasmids, which most commonly carried rep2pRE25, rep17pRUM, rep18pEF418, rep1pIP501, ω-ε-ζ and axe-txe genes. VanA isolates from 1997-2005 to 2006-2010 differed in clonal composition, prevalence of gentamicin- and tetracycline-resistance and plasmidome. Our analysis revealed high complexity of Tn1546-type transposons and vanA-plasmids, and suggested that diverse genetic events, such as conjugation transfer, recombination, chromosomal integration and DNA mutations shaped the structure of these elements among Polish VREfm.

  11. Chitosan-propolis nanoparticle formulation demonstrates anti-bacterial activity against Enterococcus faecalis biofilms

    PubMed Central

    Ong, Teik Hwa; Chitra, Ebenezer; Ramamurthy, Srinivasan; Siddalingam, Rajinikanth Paruvathanahalli; Yuen, Kah Hay; Ambu, Stephen Periathamby

    2017-01-01

    Propolis obtained from bee hives is a natural substance with antimicrobial properties. It is limited by its insolubility in aqueous solutions; hence ethanol and ethyl acetate extracts of Malaysian propolis were prepared. Both the extracts displayed antimicrobial and anti-biofilm properties against Enterococcus faecalis, a common bacterium associated with hospital-acquired infections. High performance liquid chromatography (HPLC) analysis of propolis revealed the presence of flavonoids like kaempferol and pinocembrin. This study investigated the role of propolis developed into nanoparticles with chitosan for its antimicrobial and anti-biofilm properties against E. faecalis. Bacteria that grow in a slimy layer of biofilm are resistant to penetration by antibacterial agents. The use of nanoparticles in medicine has received attention recently due to better bioavailability, enhanced penetrative capacity and improved efficacy. A chitosan-propolis nanoformulation was chosen based on ideal physicochemical properties such as particle size, zeta potential, polydispersity index, encapsulation efficiency and the rate of release of the active ingredients. This formulation inhibited E. faecalis biofilm formation and reduced the number of bacteria in the biofilm by ~90% at 200 μg/ml concentration. When tested on pre-formed biofilms, the formulation reduced bacterial number in the biofilm by ~40% and ~75% at 200 and 300 μg/ml, respectively. The formulation not only reduced bacterial numbers, but also physically disrupted the biofilm structure as observed by scanning electron microscopy. Treatment of biofilms with chitosan-propolis nanoparticles altered the expression of biofilm-associated genes in E. faecalis. The results of this study revealed that chitosan-propolis nanoformulation can be deemed as a potential anti-biofilm agent in resisting infections involving biofilm formation like chronic wounds and surgical site infections. PMID:28362873

  12. Virulence determinants and production of extracellular enzymes in Enterococcus spp. from surface water sources.

    PubMed

    Molale, Lesego Gertrude; Bezuidenhout, Cornelius Carlos

    2016-01-01

    Virulence factors in Enterococcus may be indicative of potential pathogenicity. The aim of this study was to determine the relationship between the presence of clinically relevant virulence genes, in Enterococcus spp. from environmental water, and their in vitro expression. One hundred and twenty-four Enterococcus isolates (seven species), from five surface water systems in the North West Province, South Africa, were screened for the presence of asa1, cylA, esp, gelE and hyl using polymerase chain reaction. The expression of cylA, hyl and gelE was determined by phenotypic assessments. Sixty-five percent of the isolates were positive for one virulence gene and 13% for two or more. Most frequently detected genes were gelE (32%) and cylA (28%). Enterococcal surface protein was absent in all isolates screened. The presence of virulence genes was correlated with their extracellular enzyme production. The results show that a large percentage of these environmental Enterococcus spp. possess virulence factors that could be expressed in vitro. This is a cause for concern and could have implications for individuals using this water for recreational and cultural purposes. Further investigation is required into the sources of these potential pathogenic Enterococcus isolates and measures to minimize their presence in water sources.

  13. Enterococcus species diversity in fecal samples of wild marine species as determined by real-time PCR.

    PubMed

    Medeiros, Aline Weber; Blaese Amorim, Derek; Tavares, Maurício; de Moura, Tiane Martin; Franco, Ana Claudia; d'Azevedo, Pedro Alves; Frazzon, Jeverson; Frazzon, Ana Paula Guedes

    2017-02-01

    Analyses using culture-independent molecular techniques have improved our understanding of microbial composition. The aim of this work was to identify and quantify enterococci in fecal samples of wild marine species using real-time quantitative PCR. Seven Enterococcus species were examined in fecal DNA of South American fur seals (Arctocephalus australis), Subantarctic fur seals (Arctocephalus tropicalis), green turtles (Chelonia mydas), Magellanic penguins (Spheniscus magellanicus), snowy-crowned tern (Sterna trudeaui), white-backed stilt (Himantopus melanurus), white-chinned petrels (Procellaria aequinoctialis), red knot (Calidris canutus), and black-browed albatross (Thalassarche melanophris). All Enterococcus species evaluated were detected in all fecal samples of wild marine species, with a concentration ranging between 10(6) and 10(12) copies/ng of total DNA. Differences in the enterococci distribution were observed. Enterococcus faecalis and Enterococcus mundtii were most abundant in marine mammals. Enterococcus faecalis was frequent in green turtle, Magellanic penguin, snowy-crowned tern, red knot, and black-browed albatross. Enterococcus hirae and Enterococcus gallinarum showed elevated occurrence in white-backed stilt, and Enterococcus faecium in white-chinned petrel. This study showed highest diversity of enterococci in feces of wild marine species than currently available data, and reinforced the use of culture-independent analysis to help us to enhance our understanding of enterococci in gastrointestinal tracts of wild marine species.

  14. Development of a Rapid Identification Method for the Differentiation of Enterococcus Species Using a Species-Specific Multiplex PCR Based on Comparative Genomics.

    PubMed

    Park, Jongbin; Jin, Gwi-Deuk; Pak, Jae In; Won, Jihyun; Kim, Eun Bae

    2017-04-01

    Enterococci are lactic acid bacteria that are commonly found in food and in animal gut. Since 16 S ribosomal RNA (rRNA) sequences, genetic markers for bacterial identification, are similar among several Enterococcus species, it is very difficult to determine the correct species based on only 16 S rRNA sequences. Therefore, we developed a rapid method for the identification of different Enterococcus species using comparative genomics. We compared 38 genomes of 13 Enterococcus species retrieved from the National Center of Biotechnology Information database and identified 25,623 orthologs. Among the orthologs, four genes were specific to four Enterococcus species (Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, and Enterococcus durans). We designed species-specific primer sets targeting the genes and developed a multiplex PCR using primer sets that could distinguish the four Enterococcus species among the nine strains of Enterococcus species that were available locally. The multiplex PCR method also distinguished the four species isolated from various environments, such as feces of chicken and cow, meat of chicken, cow, and pigs, and fermented soybeans (Cheonggukjang and Doenjang). These results indicated that our novel multiplex PCR using species-specific primers could identify the four Enterococcus species in a rapid and easy way. This method will be useful to distinguish Enterococcus species in food, feed, and clinical settings.

  15. Enterococcus faecalis Constitutes an Unusual Bacterial Model in Lysozyme Resistance▿

    PubMed Central

    Hébert, Laurent; Courtin, Pascal; Torelli, Riccardo; Sanguinetti, Maurizio; Chapot-Chartier, Marie-Pierre; Auffray, Yanick; Benachour, Abdellah

    2007-01-01

    Lysozyme is an important and widespread compound of the host constitutive defense system, and it is assumed that Enterococcus faecalis is one of the few bacteria that are almost completely lysozyme resistant. On the basis of the sequence analysis of the whole genome of E. faecalis V583 strain, we identified two genes that are potentially involved in lysozyme resistance, EF_0783 and EF_1843. Protein products of these two genes share significant homology with Staphylococcus aureus peptidoglycan O-acetyltransferase (OatA) and Streptococcus pneumoniae N-acetylglucosamine deacetylase (PgdA), respectively. In order to determine whether EF_0783 and EF_1843 are involved in lysozyme resistance, we constructed their corresponding mutants and a double mutant. The ΔEF_0783 mutant and ΔEF_0783 ΔEF_1843 double mutant were shown to be more sensitive to lysozyme than the parental E. faecalis JH2-2 strain and ΔEF_1843 mutant were. However, compared to other bacteria, such as Listeria monocytogenes or S. pneumoniae, the tolerance of ΔEF_0783 and ΔEF_0783 ΔEF_1843 mutants towards lysozyme remains very high. Peptidoglycan structure analysis showed that EF_0783 modifies the peptidoglycan by O acetylation of N-acetyl muramic acid, while the EF_1843 deletion has no obvious effect on peptidoglycan structure under the same conditions. Moreover, the EF_0783 and EF_1843 deletions seem to significantly affect the ability of E. faecalis to survive within murine macrophages. In all, while EF_0783 is currently involved in the lysozyme resistance of E. faecalis, peptidoglycan O acetylation and de-N-acetylation are not the main mechanisms conferring high levels of lysozyme resistance to E. faecalis. PMID:17785473

  16. Mutant prevention concentrations of daptomycin for Enterococcus faecium clinical isolates.

    PubMed

    Sinel, Clara; Jaussaud, Clara; Auzou, Michel; Giard, Jean-Christophe; Cattoir, Vincent

    2016-10-01

    Owing to the emergence of vancomycin-resistant Enterococcus faecium, treatment of enterococcal infections has become challenging. Although spontaneous in vitro resistance frequencies are low, the emergence of resistance is increasingly reported during daptomycin therapy. The mutant selection window (MSW), comprised between the minimum inhibitory concentration (MIC) and the mutant prevention concentration (MPC), corresponds to the concentration range within which resistant mutants may be selected. Since no data are available for enterococci, the aim of this study was to determine MPCs and MSWs for 12 representative E. faecium clinical isolates. MICs and MPCs were determined by broth microdilution and agar dilution methods, respectively. A basic MSW-derived pharmacodynamic analysis was also performed using mean maximum plasma concentration (Cmax) values obtained with dosages from 4 to 12 mg/kg. MICs and MPCs of daptomycin ranged from 0.5 to 4 mg/L and from 2 to 32 mg/L, respectively, with no correlation between them. The wideness of MSWs ranged from 2× to 32× MIC. Mean plasma Cmax values of daptomycin were calculated from 55 to 174.5 mg/L when using a dosage from 4 to 12 mg/kg. All Cmax values were above the MPCs whatever the dosage. Taking into account the protein binding of daptomycin (ca. 90%), the unbound fraction Cmax was just within the MSW in 67-92% of strains at recommended dosages (4-6 mg/kg) and was above the MPC for the majority of strains only with the highest dosage (12 mg/kg). This study shows that free daptomycin Cmax values usually fell into MSWs when using lower dosages (<10 mg/kg).

  17. Esp-independent biofilm formation by Enterococcus faecalis.

    PubMed

    Kristich, Christopher J; Li, Yung-Hua; Cvitkovitch, Dennis G; Dunny, Gary M

    2004-01-01

    Enterococcus faecalis is a gram-positive opportunistic pathogen known to form biofilms in vitro. In addition, this organism is often isolated from biofilms on the surfaces of various indwelling medical devices. However, the molecular mechanisms regulating biofilm formation in these clinical isolates are largely unknown. Recent work has suggested that a specific cell surface protein (Esp) of E. faecalis is critical for biofilm formation by this organism. However, in the same study, esp-deficient strains of E. faecalis were found to be capable of biofilm formation. To test the hypothesis that Esp is dispensable for biofilm formation by E. faecalis, we used microtiter plate assays and a chemostat-based biofilm fermentor assay to examine biofilm formation by genetically well-defined, non-Esp-expressing strains. Our results demonstrate that in vitro biofilm formation occurs, not only in the absence of esp, but also in the absence of the entire pathogenicity island that harbors the esp coding sequence. Using scanning electron microscopy to evaluate biofilms of E. faecalis OG1RF grown in the fermentor system, biofilm development was observed to progress through multiple stages, including attachment of individual cells to the substratum, microcolony formation, and maturation into complex multilayered structures apparently containing water channels. Microtiter plate biofilm analyses indicated that biofilm formation or maintenance was modulated by environmental conditions. Furthermore, our results demonstrate that expression of a secreted metalloprotease, GelE, enhances biofilm formation by E. faecalis. In summary, E. faecalis forms complex biofilms by a process that is sensitive to environmental conditions and does not require the Esp surface protein.

  18. In vitro inactivation of Enterococcus faecalis with a led device.

    PubMed

    D'Ercole, S; Spoto, G; Trentini, P; Tripodi, D; Petrini, M

    2016-07-01

    Non-coherent light-emitting diodes (LEDs) are effective in a large variety of clinical indications; however, the bactericidal activity of LEDs is unclear, although the effectiveness of such lights is well known. Currently, no studies have examined the effects of NIR-LED on bacteria. The aims of this study were to verify the antibacterial activity of 880-nm LED irradiation on a bacterial suspension of Enterococcus faecalis and to compare it with the actions of sodium hypochlorite (NaOCl) and the concurrent use of both treatments. Before we proceeded with the main experiment, we first performed preliminary tests to evaluate the influence of such parameters as the distance of irradiation, the energy density, the irradiation time and the presence of photosensitizers on the antimicrobial effects of LEDs. After treatment, the colony forming units per milliliter (CFU/mL) was recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. The results showed that LED irradiation, at the parameters used, is able to significantly decrease E. faecalis viability in vitro. The total inhibition of E. faecalis was obtained throughout concurrent treatment of LED and NaOCl (1%) for 5min. The same antimicrobial activity was confirmed in all of the experiments (p<0.05), but no statistically significant differences were found by varying such parameters as the distance of irradiation (from 0.5mm to 10mm), energy density (from 2.37 to 8.15mJ/s), irradiation time (from 5min to 20min) or by adding toluidine blue O (TBO).

  19. Mechanisms for Photoinactivation of Enterococcus faecalis in Seawater

    PubMed Central

    Sassoubre, Lauren M.; Nelson, Kara L.

    2012-01-01

    Field studies in fresh and marine waters consistently show diel fluctuations in concentrations of enterococci, indicators of water quality. We investigated sunlight inactivation of Enterococcus faecalis to gain insight into photoinactivation mechanisms and cellular responses to photostress. E. faecalis bacteria were exposed to natural sunlight in clear, filtered seawater under both oxic and anoxic conditions to test the relative importance of oxygen-mediated and non-oxygen-mediated photoinactivation mechanisms. Multiple methods were used to assess changes in bacterial concentration, including cultivation, quantitative PCR (qPCR), propidium monoazide (PMA)-qPCR, LIVE/DEAD staining using propidium iodide (PI), and cellular activity, including ATP concentrations and expression of the superoxide dismutase-encoding gene, sodA. Photoinactivation, based on numbers of cultivable cells, was faster in oxic than in anoxic microcosms exposed to sunlight, suggesting that oxygen-mediated photoinactivation dominated. There was little change in qPCR signal over the course of the experiment, demonstrating that the nucleic acid targets were not damaged to a significant extent. The PMA-qPCR signal was also fairly stable, consistent with the observation that the fraction of PI-permeable cells was constant. Thus, damage to the membrane was minimal. Microbial ATP concentrations decreased in all microcosms, particularly the sunlit oxic microcosms. The increase in relative expression of the sodA gene in the sunlit oxic microcosms suggests that cells were actively responding to oxidative stress. Dark repair was not observed. This research furthers our understanding of photoinactivation mechanisms and the conditions under which diel fluctuations in enterococci can be expected in natural and engineered systems. PMID:22941072

  20. Infection of Central Nervous System by Motile Enterococcus: First Case Report

    PubMed Central

    Kurup, Asok; Tee, Wen Sim Nancy; Loo, Liat Hui; Lin, Raymond

    2001-01-01

    A 66-year-old man with four indwelling ventriculoperitoneal shunts for multiloculated hydrocephalus from a complicated case of meningitis a year before developed shunt infection based on a syndrome of fever, drowsiness, and cerebrospinal fluid neutrophil pleocytosis in the background of repeated surgical manipulation to relieve successive shunt blockages. The cerebrospinal fluid culture, which yielded a motile Enterococcus species, was believed to originate from the gut. This isolate was lost in storage and could not be characterized further. The patient improved with vancomycin and high-dose ampicillin therapy. He relapsed a month later with Enterococcus gallinarum shunt infection, which responded to high-dose ampicillin and gentamicin therapy. This is probably the first case report of motile Enterococcus infection of the central nervous system. PMID:11158162

  1. [Comparison of Phoenix Automated System, API ID 32 Strep System and LightCycler Enterococcus MGRADE System in the Identification of Clinical Enterococcus Isolates].

    PubMed

    Cekin, Yeşim; Ozhak Baysan, Betil; Mutlu, Derya; Sepin Özen, Nevgün; Ongüt, Gözde; Dönmez, Levent; Oğünç, Dilara; Colak, Dilek

    2013-01-01

    Enterococci which are part of the commensal flora of the human gastrointestinal and genitourinary tracts, are increasing in importance as the cause of hospital-acquired infections. Identification of Enterococcus spp. at the species level is of great importance, for appropriate treatment of patients, infection control and to supply epidemiological data. Conventional methods for the identification of enterococcus isolates at species level is difficult and time consuming. Correct identification of enterococcus isolates in clinical microbiology laboratory by conventional methods is replaced by semi-automated or automated identification and molecular methods. The aim of this study was to evaluate the performance of Phoenix automated system (BD Diagnostic Systems, USA), API Rapid ID 32 Strep System (bioMerieux, France) and Enterococcus MGRADE LightCycler kit (Roche Molecular Biochemicals, Germany) used in real-time polymerase chain reaction (Rt-PCR), for the species level identification of enterococcus strains isolated from clinical specimens. A total of 90 vancomycin susceptible enterococci isolated from different patients were identified by all of the three commercial systems, together with conventional methods. Of the strains, 59 were identified as E.faecalis, 28 were E.faecium, and one of each as E.raffinosus, E.hirae and E.casseliflavus with conventional methods. One E.faecalis strain identified by the conventional system was identified as E.faecium by Phoenix system and one E.faecium strain as E.durans. One E.raffinosus strain identifed by the conventional method was identified as E.avium by API. Conventionally identified four E.faecalis strains were determined to be E.faecium by Rt-PCR and one E.faecium, one E.raffinosus and one E.casseliflavus as E.faecalis. Accordingly, the consistency of Phoenix, API Rapid ID 32 Strep and LightCycler Enterococcus MGRADE systems with the conventional methods were detected as 97.8% (88/90), 98.9% (89/90), and 92.2% (83

  2. Identification and Antimicrobial Resistance of Enterococcus Spp. Isolated from the River and Coastal Waters in Northern Iran

    PubMed Central

    Hajiesmaili, Reza; Talebjannat, Maryam; Yahyapour, Yousef

    2014-01-01

    As fecal streptococci commonly inhabit the intestinal tract of humans and warm blooded animals, and daily detection of all pathogenic bacteria in coastal water is not practical, thus these bacteria are used to detect the fecal contamination of water. The present study examined the presence and the antibiotic resistance patterns of Enterococcus spp. isolated from the Babolrud River in Babol and coastal waters in Babolsar. Seventy samples of water were collected in various regions of the Babolrud and coastal waters. Isolated bacteria were identified to the species level using standard biochemical tests and PCR technique. In total, 70 Enterococcus spp. were isolated from the Babolrud River and coastal waters of Babolsar. Enterococcus faecalis (68.6%) and Enterococcus faecium (20%) were the most prevalent species. Resistance to chloramphenicol, ciprofloxacin, and tetracyclin was prevalent. The presence of resistant Enterococcus spp. in coastal waters may transmit resistant genes to other bacteria; therefore, swimming in such environments is not suitable. PMID:25525617

  3. Identification and antimicrobial resistance of Enterococcus spp. isolated from the river and coastal waters in northern Iran.

    PubMed

    Alipour, Majid; Hajiesmaili, Reza; Talebjannat, Maryam; Yahyapour, Yousef

    2014-01-01

    As fecal streptococci commonly inhabit the intestinal tract of humans and warm blooded animals, and daily detection of all pathogenic bacteria in coastal water is not practical, thus these bacteria are used to detect the fecal contamination of water. The present study examined the presence and the antibiotic resistance patterns of Enterococcus spp. isolated from the Babolrud River in Babol and coastal waters in Babolsar. Seventy samples of water were collected in various regions of the Babolrud and coastal waters. Isolated bacteria were identified to the species level using standard biochemical tests and PCR technique. In total, 70 Enterococcus spp. were isolated from the Babolrud River and coastal waters of Babolsar. Enterococcus faecalis (68.6%) and Enterococcus faecium (20%) were the most prevalent species. Resistance to chloramphenicol, ciprofloxacin, and tetracyclin was prevalent. The presence of resistant Enterococcus spp. in coastal waters may transmit resistant genes to other bacteria; therefore, swimming in such environments is not suitable.

  4. Identification of vancomycin-susceptible major clones of clinical Enterococcus from Algeria.

    PubMed

    Bourafa, Nadjette; Abat, Cédric; Loucif, Lotfi; Olaitan, Abiola Olumuyiwa; Bentorki, Ahmed Aimen; Boutefnouchet, Nafissa; Rolain, Jean-Marc

    2016-09-01

    The main objectives of this study were to characterize clinical strains of Enterococcus spp. isolated from Algerian inpatients and outpatients, to investigate their susceptibility to antibiotics and to analyse their phylogenetic relatedness. A total of 85 non-duplicate Enterococcus spp. isolates collected between 2010 and 2013 from various clinical samples, including urine, vaginal swab, pus, blood and semen, from Algerian inpatients (n=62) and outpatients (n=23) were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was performed using disk diffusion and Etest methods. Clonal relatedness was analysed using multilocus sequence typing (MLST). Enterococcus faecalis was the most predominant species (75.3%), followed by Enterococcus faecium (21.2%), Enterococcus gallinarum (2.4%) and Enterococcus casseliflavus (1.2%). High-level resistance to aminoglycosides was significantly more prevalent in hospitalized patients than in outpatients. None of the E. faecalis and E. faecium isolates were resistant to vancomycin. High genetic diversity was observed among the E. faecalis isolates, with the identification of a new clonal complex (CC256), as well as the detection of E. faecalis ST6 and E. faecium lineages ST17, ST18 and ST78 associated with hospital isolates. This is the first report of E. faecalis ST6 and E. faecium ST17 and ST18 in Algeria. Although acquired vancomycin resistance was not observed among the enterococcal strains, there is a continued need to monitor the level of antibiotic resistance among enterococci as well as the evolution of the E. faecalis/E. faecium ratio.

  5. Basal Levels of (p)ppGpp in Enterococcus faecalis: the Magic beyond the Stringent Response

    PubMed Central

    Gaca, Anthony O.; Kajfasz, Jessica K.; Miller, James H.; Liu, Kuanqing; Wang, Jue D.; Abranches, Jacqueline; Lemos, José A.

    2013-01-01

    ABSTRACT The stringent response (SR), mediated by the alarmone (p)ppGpp, is a conserved bacterial adaptation system controlling broad metabolic alterations necessary for survival under adverse conditions. In Enterococcus faecalis, production of (p)ppGpp is controlled by the bifunctional protein RSH (for “Rel SpoT homologue”; also known as RelA) and by the monofunctional synthetase RelQ. Previous characterization of E. faecalis strains lacking rsh, relQ, or both revealed that RSH is responsible for activation of the SR and that alterations in (p)ppGpp production negatively impact bacterial stress survival and virulence. Despite its well-characterized role as the effector of the SR, the significance of (p)ppGpp during balanced growth remains poorly understood. Microarrays of E. faecalis strains producing different basal amounts of (p)ppGpp identified several genes and pathways regulated by modest changes in (p)ppGpp. Notably, expression of numerous genes involved in energy generation were induced in the ∆rsh ∆relQ [(p)ppGpp0] strain, suggesting that a lack of basal (p)ppGpp places the cell in a “transcriptionally relaxed” state. Alterations in the fermentation profile and increased production of H2O2 in the (p)ppGpp0 strain substantiate the observed transcriptional changes. We confirm that, similar to what is seen in Bacillus subtilis, (p)ppGpp directly inhibits the activity of enzymes involved in GTP biosynthesis, and complete loss of (p)ppGpp leads to dysregulation of GTP homeostasis. Finally, we show that the association of (p)ppGpp with antibiotic survival does not relate to the SR but rather relates to basal (p)ppGpp pools. Collectively, this study highlights the critical but still underappreciated role of basal (p)ppGpp pools under balanced growth conditions. PMID:24065631

  6. Transfer of tetracycline resistance genes with aggregation substance in food-borne Enterococcus faecalis.

    PubMed

    Choi, Jong-Mi; Woo, Gun-Jo

    2015-04-01

    Enterococcus faecalis has the ability to conjugate with the aid of aggregation substance (AS) and inducible sex pheromones to exchange genetic elements in food matrix. To evaluate the food safety condition and the transferable factor, 250 tetracycline-resistant food-borne E. faecalis were collected in Korea. Among the isolates, a majority of tetracycline-resistant isolates (49.6 %) harbored both the tet(M) and tet(L) genes together, followed by tet(M) (19.6 %), and tet(L) (6.8 %) alone. Also, we found the combination of tet(L)/tet(M)/tet(O) or tet(M)/tet(O). We identified two tet(S) genes including the isolate carrying tet(M) + tet(S) genes. Additionally, most E. faecalis were positive for cpd and ccf (both 96.8 %) followed by cob (57.2 %). Through mating experiments, we confirmed E. faecalis possessing the Int-Tn gene and/or any AS gene successfully transferred tet genes to JH2-2 E. faecalis, whereas neither E. faecalis carrying AS genes nor the Int-Tn gene showed the conjugation. Pulsed-field gel electrophoresis results supported a distinct pattern, implying transfer of genetic information. Our study revealed a high occurrence of tetracycline resistance genes in E. faecalis from various foods. The widespread dissemination of tetracycline resistance genes would be promoted to transfer tetracycline resistance genes by pheromone-mediated conjugation systems.

  7. Characterization and complete genome sequence analysis of novel bacteriophage IME-EFm1 infecting Enterococcus faecium.

    PubMed

    Wang, Yahui; Wang, Wei; Lv, Yongqiang; Zheng, Wangliang; Mi, Zhiqiang; Pei, Guangqian; An, Xiaoping; Xu, Xiaomeng; Han, Chuanyin; Liu, Jie; Zhou, Changlin; Tong, Yigang

    2014-11-01

    We isolated and characterized a novel virulent bacteriophage, IME-EFm1, specifically infecting multidrug-resistant Enterococcus faecium. IME-EFm1 is morphologically similar to members of the family Siphoviridae. It was found capable of lysing a wide range of our E. faecium collections, including two strains resistant to vancomycin. One-step growth tests revealed the host lysis activity of phage IME-EFm1, with a latent time of 30 min and a large burst size of 116 p.f.u. per cell. These biological characteristics suggested that IME-EFm1 has the potential to be used as a therapeutic agent. The complete genome of IME-EFm1 was 42 597 bp, and was linear, with terminally non-redundant dsDNA and a G+C content of 35.2 mol%. The termini of the phage genome were determined with next-generation sequencing and were further confirmed by nuclease digestion analysis. To our knowledge, this is the first report of a complete genome sequence of a bacteriophage infecting E. faecium. IME-EFm1 exhibited a low similarity to other phages in terms of genome organization and structural protein amino acid sequences. The coding region corresponded to 90.7 % of the genome; 70 putative ORFs were deduced and, of these, 29 could be functionally identified based on their homology to previously characterized proteins. A predicted metallo-β-lactamase gene was detected in the genome sequence. The identification of an antibiotic resistance gene emphasizes the necessity for complete genome sequencing of a phage to ensure it is free of any undesirable genes before use as a therapeutic agent against bacterial pathogens.

  8. Enterococcus faecalis infection activates phosphatidylinositol 3-kinase signaling to block apoptotic cell death in macrophages.

    PubMed

    Zou, Jun; Shankar, Nathan

    2014-12-01

    Apoptosis is an intrinsic immune defense mechanism in the host response to microbial infection. Not surprisingly, many pathogens have evolved various strategies to manipulate this important pathway to benefit their own survival and dissemination in the host during infection. To our knowledge, no attempts have been made to explore the host cell survival signals modulated by the bacterium Enterococcus faecalis. Here, we show for the first time that during early stages of infection, internalized enterococci can prevent host cell (RAW264.7 cells, primary macrophages, and mouse embryonic fibroblasts [MEFs]) apoptosis induced by a wide spectrum of proapoptotic stimuli. Activation of caspase 3 and cleavage of the caspase 3 substrate poly(ADP-ribose) polymerase were inhibited in E. faecalis-infected cells, indicating that E. faecalis protects macrophages from apoptosis by inhibiting caspase 3 activation. This antiapoptotic activity in E. faecalis-infected cells was dependent on the activation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, which resulted in the increased expression of the antiapoptotic factor Bcl-2 and decreased expression of the proapoptotic factor Bax. Further analysis revealed that active E. faecalis physiology was important for inhibition of host cell apoptosis, and this feature seemed to be a strain-independent trait among E. faecalis isolates. Employing a mouse peritonitis model, we also determined that cells collected from the peritoneal lavage fluid of E. faecalis-infected mice showed reduced levels of apoptosis compared to cells from uninfected mice. These results show early modulation of apoptosis during infection and have important implications for enterococcal pathogenesis.

  9. Genome-Wide Identification of Small RNAs in the Opportunistic Pathogen Enterococcus faecalis V583

    PubMed Central

    Shioya, Kouki; Michaux, Charlotte; Kuenne, Carsten; Hain, Torsten; Verneuil, Nicolas; Budin-Verneuil, Aurélie; Hartsch, Thomas; Hartke, Axel; Giard, Jean-Christophe

    2011-01-01

    Small RNA molecules (sRNAs) are key mediators of virulence and stress inducible gene expressions in some pathogens. In this work we identify sRNAs in the Gram positive opportunistic pathogen Enterococcus faecalis. We characterized 11 sRNAs by tiling microarray analysis, 5′ and 3′ RACE-PCR, and Northern blot analysis. Six sRNAs were specifically expressed at exponential phase, two sRNAs were observed at stationary phase, and three were detected during both phases. Searches of putative functions revealed that three of them (EFA0080_EFA0081 and EFB0062_EFB0063 on pTF1 and pTF2 plasmids, respectively, and EF0408_EF04092 located on the chromosome) are similar to antisense RNA involved in plasmid addiction modules. Moreover, EF1097_EF1098 shares strong homologies with tmRNA (bi-functional RNA acting as both a tRNA and an mRNA) and EF2205_EF2206 appears homologous to 4.5S RNA member of the Signal Recognition Particle (SRP) ribonucleoprotein complex. In addition, proteomic analysis of the ΔEF3314_EF3315 sRNA mutant suggests that it may be involved in the turnover of some abundant proteins. The expression patterns of these transcripts were evaluated by tiling array hybridizations performed with samples from cells grown under eleven different conditions some of which may be encountered during infection. Finally, distribution of these sRNAs among genome sequences of 54 E. faecalis strains was assessed. This is the first experimental genome-wide identification of sRNAs in E. faecalis and provides impetus to the understanding of gene regulation in this important human pathogen. PMID:21912655

  10. Genome-wide identification of small RNAs in the opportunistic pathogen Enterococcus faecalis V583.

    PubMed

    Shioya, Kouki; Michaux, Charlotte; Kuenne, Carsten; Hain, Torsten; Verneuil, Nicolas; Budin-Verneuil, Aurélie; Hartsch, Thomas; Hartke, Axel; Giard, Jean-Christophe

    2011-01-01

    Small RNA molecules (sRNAs) are key mediators of virulence and stress inducible gene expressions in some pathogens. In this work we identify sRNAs in the gram positive opportunistic pathogen Enterococcus faecalis. We characterized 11 sRNAs by tiling microarray analysis, 5' and 3' RACE-PCR, and Northern blot analysis. Six sRNAs were specifically expressed at exponential phase, two sRNAs were observed at stationary phase, and three were detected during both phases. Searches of putative functions revealed that three of them (EFA0080_EFA0081 and EFB0062_EFB0063 on pTF1 and pTF2 plasmids, respectively, and EF0408_EF04092 located on the chromosome) are similar to antisense RNA involved in plasmid addiction modules. Moreover, EF1097_EF1098 shares strong homologies with tmRNA (bi-functional RNA acting as both a tRNA and an mRNA) and EF2205_EF2206 appears homologous to 4.5S RNA member of the Signal Recognition Particle (SRP) ribonucleoprotein complex. In addition, proteomic analysis of the ΔEF3314_EF3315 sRNA mutant suggests that it may be involved in the turnover of some abundant proteins. The expression patterns of these transcripts were evaluated by tiling array hybridizations performed with samples from cells grown under eleven different conditions some of which may be encountered during infection. Finally, distribution of these sRNAs among genome sequences of 54 E. faecalis strains was assessed. This is the first experimental genome-wide identification of sRNAs in E. faecalis and provides impetus to the understanding of gene regulation in this important human pathogen.

  11. Purification and characterization of enterocin MC13 produced by a potential aquaculture probiont Enterococcus faecium MC13 isolated from the gut of Mugil cephalus.

    PubMed

    Satish Kumar, R; Kanmani, P; Yuvaraj, N; Paari, K A; Pattukumar, V; Arul, V

    2011-12-01

    A bacteriocin producer strain MC13 was isolated from the gut of Mugil cephalus (grey mullet) and identified as Enterococcus faecium. The bacteriocin of E. faecium MC13 was purified to homogeneity, as confirmed by Tricine sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE). Reverse-phase high-performance liquid chromatography (HPLC) analysis showed a single active fraction eluted at 26 min, and matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry analysis showed the molecular mass to be 2.148 kDa. The clear zone in native PAGE corresponding to enterocin MC13 band further substantiated its molecular mass. A dialyzed sample (semicrude preparation) of enterocin MC13 was broad spectrum in its action and inhibited important seafood-borne pathogens: Listeria monocytogenes , Vibrio parahaemolyticus, and Vibrio vulnificus. This antibacterial substance was sensitive to proteolytic enzymes: trypsin, protease, and chymotrypsin but insensitive to catalase and lipase, confirming that inhibition was due to the proteinaceous molecule, i.e., bacteriocin, and not due to hydrogen peroxide. Enterocin MC13 tolerated heat treatment (up to 90 °C for 20 min). Enterococcus faecium MC13 was effective in bile salt tolerance, acid tolerance, and adhesion to the HT-29 cell line. These properties reveal the potential of E. faecium MC13 to be a probiotic bacterium. Enterococcus faecium MC13 could be used as potential fish probiotic against pathogens such as V. parahaemolyticus, Vibrio harveyi, and Aeromonas hydrophila in fisheries. Also, this could be a valuable seafood biopreservative against L. monocytogenes.

  12. Glycopeptide susceptibility among Danish Enterococcus faecium and Enterococcus faecalis isolates of animal and human origin and PCR identification of genes within the VanA cluster.

    PubMed Central

    Aarestrup, F M; Ahrens, P; Madsen, M; Pallesen, L V; Poulsen, R L; Westh, H

    1996-01-01

    The MICs of vancomycin and avoparcin were determined for isolates of Enterococcus faecium and isolates of Enterococcus faecalis recovered from the feces of humans and animals in Denmark. Two hundred twenty-one of 376 (59%) isolates of E. faecium and 2 of 133 (1.5%) isolates of E. faecalis were resistant to vancomycin (MICs, 128 to > or = 256 micrograms/ml), and all vancomycin-resistant isolates were resistant to avoparcin (MICs, 64 to > or = 256 micrograms/ml). All vancomycin-resistant isolates examined carried the vanA, vanX, and vanR genes, suggesting that a gene cluster similar to that of the transposon Tn1546 was responsible for the resistance. PMID:8843309

  13. Horizontal transfer of antibiotic resistance from Enterococcus faecium of fermented meat origin to clinical isolates of E. faecium and Enterococcus faecalis.

    PubMed

    Jahan, Musarrat; Zhanel, George G; Sparling, Richard; Holley, Richard A

    2015-04-16

    Enterococcus species are part of the normal intestinal flora of a large number of mammals including humans and consequently, they can be used as indicators of faecal contamination in food and water for human consumption. Their presence in large numbers in foods may indicate a lapse in sanitation and their ability to serve as a genetic reservoir of transferable antibiotic resistance is of concern. In the present study, Enterococcus spp., isolated from commercially fermented meat and human clinical specimen were studied to determine genetic relationships. SmaI pulsed-field gel electrophoresis (PFGE) patterns exhibited genomic heterogeneity within and between both groups of isolates. However, in spite of this heterogeneity there were still substantial phenotypic similarities which suggested that food might be a potential vehicle for distribution of resistant bacteria among humans. In vitro conjugation experiments demonstrated transfer of the tetracycline resistant determinant, tet(M), from Enterococcus faecium S27 isolated from fermented sausage to clinical isolates of both E. faecium and Enterococcus faecalis. The streptomycin resistance of E. faecium S27 was also transferred to a clinical strain, E. faecalis 82916, which was confirmed by the presence of the streptomycin resistance gene, aadA, in the donor and transconjugant strains. Since the aadA gene is associated with a class 1 integron, results also suggested that resistance transfer might have occurred via an integron. It appears this is the first identification of a class 1 integron in E. faecium isolated from food. The importance of food enterococci as a reservoir of antibiotic resistance genes and the potential for their genetic transfer to human strains following consumption of uncooked or undercooked contaminated meat is underlined by this work.

  14. Erratum to: Two novel species Enterococcus lemanii sp. nov. and Enterococcus eurekensis sp. nov., isolated from a swine-manure storage pit.

    PubMed

    Cotta, Michael A; Whitehead, Terence R; Falsen, Enevold; Moore, Edward; Lawson, Paul A

    2013-06-01

    A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular genetic methods was performed on six strains of an unknown Gram-positive, nonspore-forming, facultative anaerobic coccus-shaped bacterium isolated from a swine-manure storage pit. On the basis of 16S rRNA, RNA polymerase-subunit (rpoA), and the 60-kilodalton chaperonin (cpn60) gene sequence analyses, it was shown that all the isolates were enterococci but formed two separate lines of descent. Pairwise 16S rRNA sequence comparisons demonstrated that the two novel organisms were most closely related to each other (97.9 %) and to Enterococcus aquimarinus (97.8 %). Both organisms contained major amounts of C16:0, C16:1 ω7c, and C18:1 ω7c/12t/9t as the major cellular fatty acids. Based on biochemical, chemotaxonomic, and phylogenetic evidence, the names Enterococcus lemanii sp. nov. (type strain PC32(T) = CCUG 61260(T) = NRRL B-59661(T)) and Enterococcus eurekensis sp. nov. (type strain PC4B(T) = CCUG 61259(T) = NRRL B-59662(T)) are proposed for the hitherto undescribed species.

  15. Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard

    PubMed Central

    Osman, Kamelia M.; Ali, Mohamed N.; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H.; Orabi, Ahmed; Fawzy, Nehal M.

    2016-01-01

    Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the

  16. Prevalence of enterococcus species and their virulence genes in fresh water prior to and after storm events.

    PubMed

    Sidhu, J P S; Skelly, E; Hodgers, L; Ahmed, W; Li, Y; Toze, S

    2014-01-01

    Enterococcus spp. isolates (n = 286) collected from six surface water bodies in subtropical Brisbane, Australia, prior to and after storm events, were identified to species level and tested for the presence of seven clinically important virulence genes (VGs). Enterococcus faecalis (48%), Enterococcus faecium (14%), Enterococcus mundtii (13%), and Enterococcus casseliflavus (13%) were frequently detected at all sites. The frequency of E. faecium occurrence increased from 6% in the dry period to 18% after the wet period. The endocarditis antigen (efaA), gelatinase (gelE), collagen-binding protein (ace), and aggregation substance (asa1) were detected in 61%, 43%, 43%, and 23% of Enterococcus isolates, respectively. The chances of occurrence of ace, gelE, efaA, and asa1 genes in E. faecalis were found to be much higher compared to the other Enterococcus spp. The observed odds ratio of occurrence of ace and gelE genes in E. faecalis was much higher at 7.96 and 6.40 times, respectively. The hyl gene was 3.84 times more likely to be detected in E. casseliflavus. The presence of multiple VGs in most of the E. faecalis isolates underscores the importance of E. faecalis as a reservoir of VGs in the fresh water aquatic environment. Consequently, if contaminated surface water is to be used for production of potable and nonpotable water some degree of treatment depending upon intended use such as detention in basins prior to use or chlorination is required.

  17. Draft Genome Sequence of the Tyramine Producer Enterococcus durans Strain IPLA 655.

    PubMed

    Ladero, Victor; Linares, Daniel M; Del Rio, Beatriz; Fernandez, Maria; Martin, M Cruz; Alvarez, Miguel A

    2013-05-16

    We here report a 3.059-Mbp draft assembly for the genome of Enterococcus durans strain IPLA 655. This dairy isolate provides a model for studying the regulation of the biosynthesis of tyramine (a toxic compound). These results should aid our understanding of tyramine production and allow tyramine accumulation in food to be reduced.

  18. Detection and quantification limits of the EPA Enterococcus qPCR method

    EPA Science Inventory

    The U.S. EPA will be recommending a quantitative polymerase chain reaction (qPCR) method targeting Enterococcus spp. as an option for monitoring recreational beach water quality in 2013 and has published preliminary proposed water quality criteria guidelines for the method. An im...

  19. Draft Genome Sequence of Enterococcus faecalis Strain UCD-PD3

    PubMed Central

    De Vries, Dana R.; Martin, Alexandra L.; Coil, David A.

    2016-01-01

    Here, we present the draft genome sequence of Enterococcus faecalis strain UCD-PD3. The assembly contains 2,861,314 bp in 73 contigs. This strain was isolated from a feral domestic cat (Felis catus) anal sac secretion sample, as part of a project on isolating and characterizing the microbes present in feline anal sacs. PMID:27979940

  20. Enterococcus populations in artisanal Manchego cheese: biodiversity, technological and safety aspects.

    PubMed

    Nieto-Arribas, Pedro; Seseña, Susana; Poveda, Justa M; Chicón, Rosa; Cabezas, Lourdes; Palop, Llanos

    2011-08-01

    Enterococci represent a considerable proportion of the microbiota in Manchego cheeses. In this study, a total of 132 enterococci isolated from good quality Manchego cheeses from two dairies at different ripening times were genotypically characterized and identified using molecular techniques. Representative isolates from the clusters obtained after genotyping were assayed for some enzymatic activities considered to have a potential role in cheese ripening, and for 2,3-butanedione and acetoin production, evaluation of odor intensity and appearance in milk and safety evaluation. Enterococcus faecalis was the predominant specie, accounting for 81.8% of the total isolates, while Enterococcus faecium, Enterococcus hirae and Enterococcus avium were present in low proportions. The number of genotypes involved at each ripening time varied both between dairies and with the ripening times; genotype E. faecalis Q1 being present in almost all the samples from both dairies. Eight isolates showed a higher proteolytic activity and 3 isolates produced high quantities of acetoin-diacetyl, for which reason they are interesting from a technological standpoint. A low antibiotic resistance was found and almost all the strains were susceptible to clinically important antibiotics. On the contrary, only four isolates (E. faecalis C4W1 and N0W5, and E. faecium N32W1 and C16W2) did not harbor some of the virulence genes assayed.

  1. An indigenous gut bacterium, Enterococcus faecalis (Lactobacillales: Enterococcaceae), increases seed consumption by Harpalus pensylvanicus (Coleoptera: Carabidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harpalus pensylvanicus is a beneficial beetle contributing to insect control and seed predation in North American cropland. The bacterial endosymbiont Enterococcus faecalis is found in the intestinal tract of H. pensylvanicus and is thought to contribute to the digestion of the insect's seed diet. W...

  2. Influence of enterococcal surface protein (esp) on the transport of Enterococcus faecium within saturated quartz sands.

    PubMed

    Johanson, Jennifer J; Feriancikova, Lucia; Xu, Shangping

    2012-02-07

    Enterococcus was selected by US EPA as a Gram-positive indicator microorganism for groundwater fecal contamination. It was recently reported that enterococcal surface protein (esp) was more prevalent in Enterococcus from human sources than in Enterococcus from nonhuman sources and esp could potentially be used as a source tracking tool for fecal contamination (Scott et al., 2005). In this research, we performed laboratory column transport experiments to investigate the transport of Enterococcus faecium within saturated quartz sands. Particularly, we used a wild type strain (E1162) and a mutant (E1162Δesp) to examine the influence of esp on the transport behavior of E. faecium. Our results showed that esp could significantly enhance the attachment of E. faecium cells onto the surface of silica sands and thus lower the mobility of E. faecium within sand packs. Cell surface properties (e.g., zeta potential) were determined and the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory was applied to explain the effects of esp on the retention of E. faecium. Overall, our results suggested that E. faecium strains with esp could display lower mobility within saturated sand packs than E. faecium strains without esp. The disparity in the transport behavior of E. faecium with and without esp could limit the effectiveness of esp as a source tracking tool within the groundwater system.

  3. Enterococcus diestrammenae sp. nov., isolated from the gut of Diestrammena coreana

    PubMed Central

    Kim, Joon Yong; Shin, Na-Ri; Na, Hong-Kyung; Hyun, Dong-Wook; Whon, Tae Woong; Kim, Pil Soo; Yun, Ji-Hyun

    2013-01-01

    A novel Gram-stain-positive, facultatively anaerobic, non-motile and lactic-acid-producing bacterium, designated strain ORL-24T, was isolated from the gut of the camel cricket, Diestrammena coreana. Optimal growth occurred at 37 °C, pH 8 and with 0 % (w/v) NaCl. The ratio of l-lactate to d-lactate in strain ORL-24T was 96 : 4. Lancefield antigen D was not detected. The strain was negative for oxidase activity and catalase activity. According to a phylogenetic analysis based on 16S rRNA gene sequences, strain ORL-24T was most closely related to the type strain of Enterococcus asini (96.9 % similarity). Comparative pheS and rpoA sequence analyses of strain ORL-24T indicated that the strain belonged to the genus Enterococcus. The major fatty acids were C16 : 0 and C18 : 1ω9c. The DNA G+C content was 41.3 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain ORL-24T represents a novel species of the genus Enterococcus, for which the name Enterococcus diestrammenae is proposed. The type strain is ORL-24T ( = KACC 16708T = JCM 18359T). PMID:23907226

  4. E. coli and Enterococcus in a Large Agricultural Watershed: Temporal, Hydrologic and Animal Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Populations of E. coli and Enterococcus were monitored in the South Fork of the Iowa River and the tributaries Tipton Creek and Beaver Creek. These three drainages have differing populations of swine and are dominated by corn and soybean production. Bacterial populations in stream water show strong ...

  5. Comparison of temperature effects on E. coli, Salmonella, and Enterococcus survival in surface waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare the dependencies of survival rates on temperature for indicator organisms E. coli and Enterococcus and the pathogen Salmonella in surface waters. A database consisting of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonella...

  6. Effects of ionophores on Enterococcus faecalis and E. faecium growth in pure and mixed ruminal culture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enterococcus faecalis and faecium are Gram-positive human pathogens that can live in the gastrointestinal tract of food animals. Vancomycin-resistant enterococci (VRE) are an increasing threat to humans as a nosocomial infection, as well as a reservoir of antibiotic resistance genes. Ionophores ar...

  7. Antimicrobial resistance in Enterococcus spp. isolated from environmental samples in the area of intensive poultry production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we investigated antimicrobial resistance of Enterococcus spp. from different environmental compartments including litter from two farms, 12 surface and 28 groundwater sites in an area of intensive poultry production and litter application. The enumerated isolates (n=250) were tested ...

  8. Enterococcus diestrammenae sp. nov., isolated from the gut of Diestrammena coreana.

    PubMed

    Kim, Joon Yong; Shin, Na-Ri; Na, Hong-Kyung; Hyun, Dong-Wook; Whon, Tae Woong; Kim, Pil Soo; Yun, Ji-Hyun; Bae, Jin-Woo

    2013-12-01

    A novel Gram-stain-positive, facultatively anaerobic, non-motile and lactic-acid-producing bacterium, designated strain ORL-24(T), was isolated from the gut of the camel cricket, Diestrammena coreana. Optimal growth occurred at 37 °C, pH 8 and with 0 % (w/v) NaCl. The ratio of l-lactate to d-lactate in strain ORL-24(T) was 96 : 4. Lancefield antigen D was not detected. The strain was negative for oxidase activity and catalase activity. According to a phylogenetic analysis based on 16S rRNA gene sequences, strain ORL-24(T) was most closely related to the type strain of Enterococcus asini (96.9 % similarity). Comparative pheS and rpoA sequence analyses of strain ORL-24(T) indicated that the strain belonged to the genus Enterococcus. The major fatty acids were C16 : 0 and C18 : 1ω9c. The DNA G+C content was 41.3 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain ORL-24(T) represents a novel species of the genus Enterococcus, for which the name Enterococcus diestrammenae is proposed. The type strain is ORL-24(T) ( = KACC 16708(T) = JCM 18359(T)).

  9. Performance of Vitek 2 for antimicrobial susceptibility testing of Staphylococcus spp. and Enterococcus spp.

    PubMed

    Bobenchik, April M; Hindler, Janet A; Giltner, Carmen L; Saeki, Sandra; Humphries, Romney M

    2014-02-01

    Vitek 2 (bioMérieux, Inc., Durham, NC) is a widely used commercial antimicrobial susceptibility testing system. We compared MIC results obtained by Vitek 2 to those obtained by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) reference method for 134 staphylococcal and 84 enterococcal clinical isolates. Nineteen agents were evaluated, including all those available on Vitek 2 for testing staphylococci and enterococci. The resistance phenotypes tested included methicillin-resistant Staphylococcus aureus (MRSA) (n = 58), S. aureus with inducible clindamycin resistance (ICR) (n = 30), trimethoprim-sulfamethoxazole-resistant MRSA (n = 10), vancomycin-resistant Enterococcus (n = 37), high-level gentamicin-resistant Enterococcus (n = 15), linezolid-resistant Enterococcus (n = 5), and daptomycin-nonsusceptible Enterococcus faecalis (n = 6). For the staphylococci, there was 98.9% categorical agreement (CA). There was one very major error (VME) for gentamicin in a Staphylococcus hominis isolate, six VMEs for inducible clindamycin in S. aureus isolates, and two major errors (ME) for daptomycin in an S. aureus and a Staphylococcus epidermidis isolate. For enterococci, there was 97.3% CA. Two VMEs were observed for daptomycin in isolates of E. faecalis and 2 ME, 1 for high-level gentamicin resistance and 1 for nitrofurantoin, in E. faecium isolates. Overall, there was 98.3% CA and 99% essential agreement for the testing of staphylococci and enterococci by the Vitek 2. With the exception of detecting ICR in S. aureus, Vitek 2 performed reliably for antimicrobial susceptibility testing of staphylococci and enterococci.

  10. Antimicrobial resistance, virulence determinants, and genetic profiles of clinical and nonclinical Enterococcus cecorum from poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although enterococci are considered commensal bacteria, they are capable of causing disease in humans and animals. Enterococcus cecorum has been implicated as a possible cause of disease in poultry across the world. However, the characteristics that contribute to pathogenesis of E. cecorum in poul...

  11. Comparison of antimicrobial resistance determinants among Salmonella, Campylobacter, Escherichia coli, and Enterococcus isolated from Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: The importance of Salmonella, Campylobacter, E.coli, and Enterococcus as carriers of antimicrobial resistance is well known, but limited work has been done to examine the relationship between this phenotypic characteristic and genotypic attributes among strains isolated in similar set...

  12. Investigation of genes involved in nisin production in Enterococcus spp. strains isolated from raw goat milk.

    PubMed

    Perin, Luana Martins; Todorov, Svetoslav Dimitrov; Nero, Luís Augusto

    2016-09-01

    Different strains of Lactococcus lactis are capable of producing the bacteriocin nisin. However, genetic transfer mechanisms allow the natural occurrence of genes involved in nisin production in members of other bacterial genera, such as Enterococcus spp. In a previous study, nisA was identified in eight enterococci capable of producing antimicrobial substances. The aim of this study was to verify the presence of genes involved in nisin production in Enterococcus spp. strains, as well as nisin expression. The nisA genes from eight Enterococcus spp. strains were sequenced and the translated amino acid sequences were compared to nisin amino-acid sequences previously described in databases. Although containing nisin structural and maturation related genes, the enterococci strains tested in the present study did not present the immunity related genes (nisFEG and nisI). The translated sequences of nisA showed some point mutations, identical to those presented by Lactococcus strains isolated from goat milk. All enterococci were inhibited by nisin, indicating the absence of immunity and thus that nisin cannot be expressed. This study demonstrated for the first time the natural occurrence of nisin structural genes in Enterococcus strains and highlights the importance of providing evidence of a link between the presence of bacteriocin genes and their expression.

  13. Biotechnological and safety characterization of Enterococcus lactis, a recently described species of dairy origin.

    PubMed

    Morandi, Stefano; Silvetti, Tiziana; Brasca, Milena

    2013-01-01

    The biotechnological and safety properties of a recently described enterococcal species, Enterococcus lactis, were investigated. With regard to the technological properties, in milk all the strains tested had weak acidifying and proteolytic activities, generally medium reduction activity over 24 h (-102 mV < Eh < -2 mV) and low lipolytic activity on tributyrin agar. The isolates were tested for resistance against 14 antibiotics and none of the studied strains were classified as resistant to clinically important antibiotics such as ampicillin, erythromycin, penicillin G, tetracycline and vancomycin. Furthermore, PCR-based detection did not identify any of the common genetic determinants for vancomycin, tetracycline and erythromycin resistance. The E. lactis strains showed good survival in simulated in vitro digestion and were able to inhibit the growth of Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Clostridium sporogenes, Clostridium tyrobutyricum and Pseudomonas syringae. Screening for enterocin structural genes showed that all isolates harboured the entP gene. The presence of nine virulence factor genes (cylA, asa1, gelE, hyl, esp, ace, efaA, hdc and tdc) was investigated by PCR and no virulence determinants were detected. This study highlights that the recently described E. lactis may be a potential source of novel strains with interesting features that could be used for fermented dairy foods.

  14. Properties of durancin GL, a new antilisterial bacteriocin produced by Enterococcus durans 41D

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The properties of the antilisterial durancin GL were characterized. The bacteriocin was the product of Enterococcus durans 41D which was isolated from Hispanic-style cheese samples. The antibacterial activity of durancin GL was only evident against Gram-positive bacteria, including Listeria specie...

  15. Characterization of Antimicrobial Resistance Determinants among Salmonella, Campylobacter, Escherichia, and Enterococcus using PCR and Microarray Approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella, Campylobacter, Escherichia, and Enterococcus can be important carriers of antimicrobial resistance. Limited work has been done to examine the relationship among strains co-cultured from the gastrointestinal tract of individual animals. To address this, 1284 isolates were collected from s...

  16. Individual variability in finger-to-finger transmission efficiency of Enterococcus faecium clones

    PubMed Central

    del Campo, Rosa; Sánchez-Díaz, Ana María; Zamora, Javier; Torres, Carmen; Cintas, Luis María; Franco, Elvira; Cantón, Rafael; Baquero, Fernando

    2014-01-01

    A fingertip-to-fingertip intraindividual transmission experiment was carried out in 30 healthy volunteers, using four MLST-typed Enterococcus faecium clones. Overall results showed an adequate fit goodness to a theoretical exponential model, whereas four volunteers (13%) exhibited a significantly higher finger-to-finger bacterial transmission efficiency. This observation might have deep consequences in nosocomial epidemiology. PMID:24382843

  17. Enterococcus durans endocarditis in a patient with transposition of the great vessels.

    PubMed

    Stepanović, S; Jovanović, M; Lavadinović, L; Stosović, B; Pelemis, M

    2004-03-01

    A case of native valve endocarditis caused by Enterococcus durans in a patient with transposition of the great vessels is reported. The patient was treated initially with gentamicin and ceftriaxone; after isolation of enterococci, ceftriaxone was switched to ampicillin. The only virulence factors established in the strain were haemolytic activity and biofilm formation.

  18. Draft Genome Sequence of a Vancomycin-Resistant and Vancomycin-Dependent Enterococcus faecium Isolate

    PubMed Central

    Blaschitz, Marion; Lepuschitz, Sarah; Wagner, Laura; Allerberger, Franz; Indra, Alexander; Huhulescu, Steliana

    2016-01-01

    Vancomycin-resistant enterococci have emerged as major nosocomial pathogens worldwide. While antimicrobial pressure promotes nosocomial colonization with these enterococci, prolonged exposure to vancomycin may foster the transition from vancomycin resistance to vancomycin dependence. Here, we report the draft genome sequence of a vancomycin-dependent Enterococcus faecium isolate showing partial teicoplanin dependence. PMID:27056211

  19. Complete Genome Sequence of Enterococcus faecalis Strain W11 Isolated from an Algal Food Product

    PubMed Central

    Takizawa, Noboru

    2016-01-01

    Here, we report the complete genome sequence of Enterococcus faecalis strain W11 isolated from an algal food product in Japan. This study should facilitate the identification of a novel mechanism of glycerol metabolic control in lactic acid bacteria. PMID:27688337

  20. Comparing Temperature Effects on E. Coli, Salmonella, and Enterococcus Survival in Surface Waters

    EPA Science Inventory

    The objective of this study was to compare dependency of survival rates on temperature for indicator organisms E. coli and Enterococcus and the pathogen Salmonella in surface waters. A database of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonel...

  1. REAL-TIME PCR METHOD TO DETECT ENTEROCOCCUS FAECALIS IN WATER

    EPA Science Inventory

    A 16S rDNA real-time PCR method was developed to detect Enterococcus faecalis in water samples. The dynamic range for cell detection spanned five logs and the detection limit was determined to be 6 cfu/reaction. The assay was capable of detecting E. faecalis cells added to biof...

  2. Virulence factors of Enterococcus strains isolated from patients with inflammatory bowel disease

    PubMed Central

    Golińska, Edyta; Tomusiak, Anna; Gosiewski, Tomasz; Więcek, Grażyna; Machul, Agnieszka; Mikołajczyk, Diana; Bulanda, Małgorzata; Heczko, Piotr B; Strus, Magdalena

    2013-01-01

    AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reaction (PCR) was applied to assess the presence of genes that encode virulence factors [surface aggregating protein (asa1), gelatinase (gelE), cytolysin (cylA), extracellular surface protein (esp) and hyaluronidase (hyl)] in the genomic DNA of 28 strains of Enterococcus isolated from the intestinal tissues of children with IBD (n = 16) and of children without IBD (controls; n = 12). Additionally, strains with confirmed presence of the gelE gene were tested by PCR for the presence of quorum sensing genes (fsrA, fsrB, fsrC) that control the gelatinase production. Gelatinase activity was tested on agar plates containing 1.6% gelatin. We also analysed the ability of Enterococcus strains to release and decompose hydrogen peroxide (using Analytical Merckoquant peroxide test strips) and tested their ability to adhere to Caco-2 human gut epithelium cells and form biofilms in vitro. RESULTS: A comparison of the genomes of Enterococcus strains isolated from the inflamed mucosa of patients with IBD with those of the control group showed statistically significant differences in the frequency of the asa1 gene and the gelE gene. Furthermore, the cumulative occurrence of different virulence genes in the genome of a single strain of Enterococcus isolated from the IBD patient group is greater than in a strain from the control group, although no significant difference was found. Statistically significant differences in the decomposition of hydrogen peroxide and adherence to the Caco-2 epithelial cell line between the strains from the patient group and control group were demonstrated. The results also showed that profuse biofilm production was more frequent among Enterococcus strains isolated from children with IBD than in control strains. CONCLUSION: Enterococcus strains

  3. Comparative study of bacteremias caused by Enterococcus spp. with and without high-level resistance to gentamicin. The Grupo Andaluz para el estudio de las Enfermedades Infecciosas.

    PubMed

    Caballero-Granado, F J; Cisneros, J M; Luque, R; Torres-Tortosa, M; Gamboa, F; Díez, F; Villanueva, J L; Pérez-Cano, R; Pasquau, J; Merino, D; Menchero, A; Mora, D; López-Ruz, M A; Vergara, A

    1998-02-01

    A prospective, multicenter study was carried out over a period of 10 months. All patients with clinically significant bacteremia caused by Enterococcus spp. were included. The epidemiological, microbiological, clinical, and prognostic features and the relationship of these features to the presence of high-level resistance to gentamicin (HLRG) were studied. Ninety-three patients with enterococcal bacteremia were included, and 31 of these cases were caused by HLRG (33%). The multivariate analysis selected chronic renal failure, intensive care unit stay, previous use of antimicrobial agents, and Enterococcus faecalis species as the independent risk factors that influenced the development of HLRG. The strains with HLRG showed lower levels of susceptibility to penicillin and ciprofloxacin. Clinical features (except for chronic renal failure) were similar in both groups of patients. HLRG did not influence the prognosis for patients with enterococcal bacteremia in terms of either the crude mortality rate (29% for patients with bacteremia caused by enterococci with HLRG and 28% for patients not infected with strains with HLRG) or the hospital stay after the acquisition of enterococcal bacteremia. Hemodynamic compromise, inappropriate antimicrobial therapy, and mechanical ventilation were revealed in the multivariate analysis to be the independent risk factors for mortality. Prolonged hospitalization was associated with the nosocomial acquisition of bacteremia and polymicrobial infections.

  4. The Generalist Inside the Specialist: Gut Bacterial Communities of Two Insect Species Feeding on Toxic Plants Are Dominated by Enterococcus sp.

    PubMed Central

    Vilanova, Cristina; Baixeras, Joaquín; Latorre, Amparo; Porcar, Manuel

    2016-01-01

    Some specialist insects feed on plants rich in secondary compounds, which pose a major selective pressure on both the phytophagous and the gut microbiota. However, microbial communities of toxic plant feeders are still poorly characterized. Here, we show the bacterial communities of the gut of two specialized Lepidoptera, Hyles euphorbiae and Brithys crini, which exclusively feed on latex-rich Euphorbia sp. and alkaloid-rich Pancratium maritimum, respectively. A metagenomic analysis based on high-throughput sequencing of the 16S rRNA gene revealed that the gut microbiota of both insects is dominated by the phylum Firmicutes, and especially by the common gut inhabitant Enterococcus sp. Staphylococcus sp. are also found in H. euphorbiae though to a lesser extent. By scanning electron microscopy, we found a dense ring-shaped bacterial biofilm in the hindgut of H. euphorbiae, and identified the most prominent bacterium in the biofilm as Enterococcus casseliflavus through molecular techniques. Interestingly, this species has previously been reported to contribute to the immobilization of latex-like molecules in the larvae of Spodoptera litura, a highly polyphagous lepidopteran. The E. casseliflavus strain was isolated from the gut and its ability to tolerate natural latex was tested under laboratory conditions. This fact, along with the identification of less frequent bacterial species able to degrade alkaloids and/or latex, suggest a putative role of bacterial communities in the tolerance of specialized insects to their toxic diet. PMID:27446044

  5. First report of multiresistance gene cfr in Enterococcus species casseliflavus and gallinarum of swine origin.

    PubMed

    Liu, Yang; Wang, Yang; Dai, Lei; Wu, Congming; Shen, Jianzhong

    2014-06-04

    The aim of this study was to investigate the presence and genetic environment of the multiresistance gene cfr in Enterococcus species of swine origin. Twenty-five cfr-carrying Enterococcus isolates were collected from swine in Beijing, Guangzhou, and Shandong, China. The isolates consist of 24 Enterococcus casseliflavus and one Enterococcus gallinarum isolate, and exhibited six SmaI PFGE patterns. The cfr gene was located on plasmids in all isolates except E. casseliflavus En83, in which cfr was located on the chromosomal DNA. The cfr gene environments in most of these isolates contain DNA sequences similar to pEF-01, which was first found in Enterococcus. However, inverse PCR analysis suggested that the cfr-carrying circular forms might be different from pEF-01. The circular forms in Eg51 and its transconjugant, and En23, En10, and En94 are similar to the circular form in pEF-01, except for the truncated IS1216, which is replaced by a transposase of the IS256 family in En24. The cfr circular form could not be detected in either En77 or En83, and the same cfr-carrying segments of ∼ 10 kb had only 3500bp of sequence similar to pEF-01. This is the first report of cfr gene in E. casseliflavus and E. gallinarum. The potential dissemination of the multidrug resistance gene amongst different bacterial species, especially in enterococci of human and animal origins, is concerning and should be closely monitored.

  6. Characterization of aminoglycoside resistance and virulence genes among Enterococcus spp. isolated from a hospital in China.

    PubMed

    Li, Wanxiang; Li, Jing; Wei, Quhao; Hu, Qingfeng; Lin, Xiaowei; Chen, Mengquan; Ye, Renji; Lv, Huoyang

    2015-03-11

    This study investigated the aminoglycoside resistance phenotypes and genotypes, as well as the prevalence of virulence genes, in Enterococcus species isolated from clinical patients in China. A total of 160 enterococcal isolates from various clinical samples collected from September 2013 to July 2014 were identified to the species level using the VITEK-2 COMPACT system. The antimicrobial susceptibilities of the identified Enterococcus strains were determined by the Kirby-Bauer (K-B) disc diffusion method. PCR-based assays were used to detect the aminoglycoside resistance and virulence genes in all enterococcal isolates. Of 160 Enterococcus isolates, 105 were identified as E. faecium, 35 as E. faecalis, and 20 isolates were classified as "other" Enterococcus species. High-level aminoglycoside resistance (HLAR) for gentamicin, streptomycin, and both antibiotics was identified in 58.8, 50, and 34.4% of strains, respectively. The most common virulence gene (50.6% of isolates) was efaA, followed by asa1 (28.8%). The most prevalent aminoglycoside resistance genes were aac(6')-Ie-aph(2''), aph(2')-Id, aph(3')-IIIa, and ant(6')-Ia, present in 49.4%, 1.3%, 48.8% and 31.3% of strains, respectively. Overall, E. faecium and E. faecalis were most frequently associated with hospital-acquired enterococcal infections in Zhejiang Province. All aminoglycoside resistance genes, except aph(2'')-Id, were significantly more prevalent in HLAR strains than amongst high level aminoglycoside susceptible (HLAS) strains, while there was no significant difference between HLAR and HLAS strains in regard to the prevalence of virulence genes, apart from esp, therefore, measures should be taken to manage infections caused by multi-drug resistant Enterococcus species.

  7. Retrospective analysis of Salmonella, Campylobacter, Escherichia coli, and Enterococcus in animal feed ingredients.

    PubMed

    Ge, Beilei; LaFon, Patricia C; Carter, Peggy J; McDermott, Shawn D; Abbott, Jason; Glenn, Althea; Ayers, Sherry L; Friedman, Sharon L; Paige, Joseph C; Wagner, David D; Zhao, Shaohua; McDermott, Patrick F; Rasmussen, Mark A

    2013-08-01

    The presence and antimicrobial susceptibility of foodborne pathogens and indicator organisms in animal feed are not well understood. In this study, a total of 201 feed ingredient samples (animal byproducts, n=122; plant byproducts, n=79) were collected in 2002 and 2003 from representative rendering plants and the oilseed (or cereal grain) industry across the United States. The occurrence and antimicrobial susceptibility of four bacterial genera (Salmonella, Campylobacter, Escherichia coli, and Enterococcus) were determined. Salmonella isolates were further characterized by serotyping and pulsed-field gel electrophoresis (PFGE). None of the samples yielded Campylobacter or E. coli O157:H7, whereas Salmonella, generic E. coli, and Enterococcus were present in 22.9%, 39.3%, and 86.6% of samples, respectively. A large percentage (47.8%) of Salmonella-positive samples harbored two serovars, and the vast majority (88.4%) of Enterococcus isolates were E. faecium. Animal byproducts had a significantly higher Salmonella contamination rate (34.4%) than plant byproducts (5.1%) (p<0.05). Among 74 Salmonella isolates recovered, 27 serovars and 55 PFGE patterns were identified; all were pan-susceptible to 17 antimicrobials tested. E. coli isolates (n=131) demonstrated similar susceptibility to these antimicrobials except for tetracycline (15.3% resistance), sulfamethoxazole (7.6%), streptomycin (4.6%), ampicillin (3.8%), and nalidixic acid (1.5%). Enterococcus isolates (n=362) were also resistant to five of 17 antimicrobials tested, ranging from 1.1% to penicillin to 14.6% to tetracycline. Resistance rates were generally higher among isolates recovered from animal byproducts. Taken together, our findings suggest that diverse populations of Salmonella, E. coli, and Enterococcus are commonly present in animal feed ingredients, but antimicrobial resistance is not common. Future large-scale studies to monitor these pathogenic and indicator organisms in feed commodities is warranted.

  8. Bacteriocin protein BacL1 of Enterococcus faecalis is a peptidoglycan D-isoglutamyl-L-lysine endopeptidase.

    PubMed

    Kurushima, Jun; Hayashi, Ikue; Sugai, Motoyuki; Tomita, Haruyoshi

    2013-12-27

    Enterococcus faecalis strains are commensal bacteria in humans and other animals, and they are also the causative agent of opportunistic infectious diseases. Bacteriocin 41 (Bac41) is produced by certain E. faecalis clinical isolates, and it is active against other E. faecalis strains. Our genetic analyses demonstrated that the extracellular products of the bacL1 and bacA genes, which are encoded in the Bac41 operon, coordinately express the bacteriocin activity against E. faecalis. In this study, we investigated the molecular functions of the BacL1 and BacA proteins. Immunoblotting and N-terminal amino acid sequence analysis revealed that BacL1 and BacA are secreted without any processing. The coincidental treatment with the recombinant BacL1 and BacA showed complete bacteriocin activity against E. faecalis, but neither BacL1 nor BacA protein alone showed the bacteriocin activity. Interestingly, BacL1 alone demonstrated substantial degrading activity against the cell wall fraction of E. faecalis in the absence of BacA. Furthermore, MALDI-TOF MS analysis revealed that BacL1 has a peptidoglycan D-isoglutamyl-L-lysine endopeptidase activity via a NlpC/P60 homology domain. These results collectively suggest that BacL1 serves as a peptidoglycan hydrolase and, when BacA is present, results in the lysis of viable E. faecalis cells.

  9. Hospital and Community Ampicillin-Resistant Enterococcus faecium Are Evolutionarily Closely Linked but Have Diversified through Niche Adaptation

    PubMed Central

    de Regt, Marieke J. A.; van Schaik, Willem; van Luit-Asbroek, Miranda; Dekker, Huberta A. T.; van Duijkeren, Engeline; Koning, Catherina J. M.; Bonten, Marc J. M.; Willems, Rob J. L.

    2012-01-01

    Background Ampicillin-resistant Enterococcus faecium (ARE) has emerged as a nosocomial pathogen. Here, we quantified ARE carriage in different community sources and determined genetic relatedness with hospital ARE. Methods and Results ARE was recovered from rectal swabs of 24 of 79 (30%) dogs, 11 of 85 (13%) cats and 0 of 42 horses and from 3 of 40 (8%) faecal samples of non-hospitalized humans receiving amoxicillin. Multi-locus Sequence Typing revealed 21 sequence types (STs), including 5 STs frequently associated with hospital-acquired infections. Genes previously found to be enriched in hospital ARE, such as IS16, orf903, orf905, orf907, were highly prevalent in community ARE (≥79%), while genes with a proposed role in pathogenesis, such as esp, hyl and ecbA, were found rarely (≤5%) in community isolates. Comparative genome analysis of 2 representative dog isolates revealed that the dog strain of ST192 was evolutionarily closely linked to two previously sequenced hospital ARE, but had, based on gene content, more genes in common with the other, evolutionarily more distantly related, dog strain (ST266). Conclusion ARE were detected in dogs, cats and sporadically in healthy humans, with evolutionary linkage to hospital ARE. Yet, their accessory genome has diversified, probably as a result of niche adaptation. PMID:22363425

  10. Ampicillin in Combination with Ceftaroline, Cefepime, or Ceftriaxone Demonstrates Equivalent Activities in a High-Inoculum Enterococcus faecalis Infection Model.

    PubMed

    Luther, Megan K; Rice, Louis B; LaPlante, Kerry L

    2016-05-01

    Ampicillin-ceftriaxone combination therapy has become a predominant treatment for serious Enterococcus faecalis infections, such as endocarditis. Unfortunately, ceftriaxone use is associated with future vancomycin-resistant enterococcus colonization. We evaluated E. faecalis in an in vitro pharmacodynamic model against simulated human concentration-time profiles of ampicillin plus ceftaroline, cefepime, ceftriaxone, or gentamicin. Ampicillin-cefepime and ampicillin-ceftaroline demonstrated activities similar to those of ampicillin-ceftriaxone against E. faecalis.

  11. Development of quantitative PCR assays targeting the 16S rRNA genes of Enterococcus spp. and their application to the identification of enterococcus species in environmental samples.

    PubMed

    Ryu, Hodon; Henson, Michael; Elk, Michael; Toledo-Hernandez, Carlos; Griffith, John; Blackwood, Denene; Noble, Rachel; Gourmelon, Michèle; Glassmeyer, Susan; Santo Domingo, Jorge W

    2013-01-01

    The detection of environmental enterococci has been determined primarily by using culture-based techniques that might exclude some enterococcal species as well as those that are nonculturable. To address this, the relative abundances of enterococci were examined by challenging fecal and water samples against a currently available genus-specific assay (Entero1). To determine the diversity of enterococcal species, 16S rRNA gene-based group-specific quantitative PCR (qPCR) assays were developed and evaluated against eight of the most common environmental enterococcal species. Partial 16S rRNA gene sequences of 439 presumptive environmental enterococcal strains were analyzed to study further the diversity of enterococci and to confirm the specificities of group-specific assays. The group-specific qPCR assays showed relatively high amplification rates with targeted species (>98%), although some assays cross-amplified with nontargeted species (1.3 to 6.5%). The results with the group-specific assays also showed that different enterococcal species co-occurred in most fecal samples. The most abundant enterococci in water and fecal samples were Enterococcus faecalis and Enterococcus faecium, although we identified more water isolates as Enterococcus casseliflavus than as any of the other species. The prevalence of the Entero1 marker was in agreement with the combined number of positive signals determined by the group-specific assays in most fecal samples, except in gull feces. On the other hand, the number of group-specific assay signals was lower in all water samples tested, suggesting that other enterococcal species are present in these samples. While the results highlight the value of genus- and group-specific assays for detecting the major enterococcal groups in environmental water samples, additional studies are needed to determine further the diversity, distributions, and relative abundances of all enterococcal species found in water.

  12. Molecular characterization of resistance, virulence and clonality in vancomycin-resistant Enterococcus faecium and Enterococcus faecalis: A hospital-based study in Beijing, China.

    PubMed

    Yang, Jing-xian; Li, Tong; Ning, Yong-zhong; Shao, Dong-hua; Liu, Jing; Wang, Shu-qin; Liang, Guo-wei

    2015-07-01

    The incidence of vancomycin-resistant enterococcus (VRE) in China is increasing, the molecular epidemiology of VRE in China is only partly known. This study was conducted to assess the molecular characterization of resistance, virulence and clonality of 69 vancomycin-resistant Enterococcus faecium (VREfm) and seven vancomycin-resistant Enterococcus faecalis (VREfs) isolates obtained from a Chinese hospital between July 2011 and July 2013. The glycopeptide resistance genes (VanA and VanB) were screened by multiplex PCR. The presence of five putative virulence genes (esp, gelE, asa1, hyl and cylA) were evaluated by another multiplex PCR. Multilocus sequence typing (MLST) scheme was used to assess the clonality. All 76 VRE isolates exhibited VanA phenotype and harbored VanA gene. Esp was the only gene detected both in VREfm and VREfs strains, accounting for 89.9% and 42.9%, respectively. The hyl gene was merely positive in 27.5% of VREfm strains. MLST analysis demonstrated three STs (ST6, ST4 and ST470) in VREfs and twelve STs (ST78, ST571, ST17, ST564, ST389, ST18, ST547, ST341, ST414, ST343, ST262 and ST203) in VREfm, which were all designated as CC17 by eBURST algorithm. An outbreak of VREfm belonging to ST571 was found to happen within the neurology ward in this hospital. To our knowledge, this is the first report of ST6 (CC2) VREfs strains in China and the first outbreak report of VREfm strains belonging to ST571 around the world. Our data could offer important information for understanding the molecular features of VRE in China.

  13. Inhibitory influence of Enterococcus faecium on the propagation of swine influenza A virus in vitro.

    PubMed

    Wang, Zhenya; Chai, Weidong; Burwinkel, Michael; Twardziok, Sven; Wrede, Paul; Palissa, Christiane; Esch, Bettina; Schmidt, Michael F G

    2013-01-01

    The control of infectious diseases such as swine influenza viruses (SwIV) plays an important role in food production both from the animal health and from the public health point of view. Probiotic microorganisms and other health improving food supplements have been given increasing attention in recent years, but, no information on the effects of probiotics on swine influenza virus is available. Here we address this question by assessing the inhibitory potential of the probiotic Enterococcus faecium NCIMB 10415 (E. faecium) on the replication of two porcine strains of influenza virus (H1N1 and H3N2 strain) in a continuous porcine macrophage cell line (3D4/21) and in MDBK cells. Cell cultures were treated with E. faecium at the non-toxic concentration of 1×10(6) CFU/ml in growth medium for 60 to 90 min before, during and after SwIV infection. After further incubation of cultures in probiotic-free growth medium, cell viability and virus propagation were determined at 48 h or 96 h post infection. The results obtained reveal an almost complete recovery of viability of SwIV infected cells and an inhibition of virus multiplication by up to four log units in the E. faecium treated cells. In both 3D4/21- and MDBK-cells a 60 min treatment with E. faecium stimulated nitric oxide (NO) release which is in line with published evidence for an antiviral function of NO. Furthermore, E. faecium caused a modified cellular expression of selected mediators of defence in 3D4-cells: while the expression of TNF-α, TLR-3 and IL-6 were decreased in the SwIV-infected and probiotic treated cells, IL-10 was found to be increased. Since we obtained experimental evidence for the direct adsorptive trapping of SwIV through E. faecium, this probiotic microorganism inhibits influenza viruses by at least two mechanisms, direct physical interaction and strengthening of innate defence at the cellular level.

  14. Enterococcus and Streptococcus spp. associated with chronic and self-medicated urinary tract infections in Vietnam

    PubMed Central

    2012-01-01

    Background Urinary tract infections (UTI) are one of the most common infections among women worldwide. E. coli often causes more than 75% of acute uncomplicated UTI, however, little is known about how recurrent UTIs and indiscriminate use of antimicrobials affect the aetiology of UTIs. This study aimed to establish the aetiology of UTI in a population of recurrent and self-medicated patients referred from pharmacies to a hospital in Hanoi, Vietnam and to describe genotypes and antimicrobial susceptibility of the associated bacterial pathogens. The aetiology of bacterial pathogens associated with UTI (defined as ≥ 104 CFU/ml urine) was established by phenotypic and molecular methods. Enterococcus faecalis isolates were typed by Multi Locus Sequence Typing (MLST), Pulsed-Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility testing. Methods Urine samples from 276 patients suffering symptoms of urinary tract infection were collected and cultured on Flexicult agar® allowing for detection of the most common urine pathogens. Patients were interviewed about underlying diseases, duration of symptoms, earlier episodes of UTI, number of episodes diagnosed by doctors and treatment in relation to UTI. All tentative E. faecalis and E. faecium isolates were identified to species level by PCR, 16S rRNA and partial sequencing of the groEL gene. E. faecalis isolates were further characterized by Multi Locus Sequence Typing and antimicrobial susceptibility testing. Results Mean age of 49 patients was 48 yrs (range was 11–86 yrs) and included 94% women. On average, patients reported to have suffered from UTI for 348 days (range 3 days-10 years, and experienced 2.7 UTIs during the previous year). Cephalosporins were reported the second drug of choice in treatment of UTI at the hospital. E. faecalis (55.1%), E. coli (12.2%) and Streptococcus gallolyticus subsp. pasteurianus (8.2%) were main bacterial pathogens. MIC testing of E. faecalis showed susceptibility to

  15. Behavior of Listeria monocytogenes in a multi-species biofilm with Enterococcus faecalis and Enterococcus faecium and control through sanitation procedures.

    PubMed

    da Silva Fernandes, Meg; Kabuki, Dirce Yorika; Kuaye, Arnaldo Yoshiteru

    2015-05-04

    The formation of mono-species biofilm (Listeria monocytogenes) and multi-species biofilms (Enterococcus faecium, Enterococcus faecalis, and L. monocytogenes) was evaluated. In addition, the effectiveness of sanitation procedures for the control of the multi-species biofilm also was evaluated. The biofilms were grown on stainless steel coupons at various incubation temperatures (7, 25 and 39°C) and contact times (0, 1, 2, 4, 6 and 8 days). In all tests, at 7°C, the microbial counts were below 0.4 log CFU/cm(2) and not characteristic of biofilms. In mono-species biofilm, the counts of L. monocytogenes after 8 days of contact were 4.1 and 2.8 log CFU/cm(2) at 25 and 39°C, respectively. In the multi-species biofilms, Enterococcus spp. were present at counts of 8 log CFU/cm(2) at 25 and 39°C after 8 days of contact. However, the L. monocytogenes in multi-species biofilms was significantly affected by the presence of Enterococcus spp. and by temperature. At 25°C, the growth of L. monocytogenes biofilms was favored in multi-species cultures, with counts above 6 log CFU/cm(2) after 8 days of contact. In contrast, at 39°C, a negative effect was observed for L. monocytogenes biofilm growth in mixed cultures, with a significant reduction in counts over time and values below 0.4 log CFU/cm(2) starting at day 4. Anionic tensioactive cleaning complemented with another procedure (acid cleaning, disinfection or acid cleaning+disinfection) eliminated the multi-species biofilms under all conditions tested (counts of all micro-organisms<0.4 log CFU/cm(2)). Peracetic acid was the most effective disinfectant, eliminating the multi-species biofilms under all tested conditions (counts of the all microorganisms <0.4 log CFU/cm(2)). In contrast, biguanide was the least effective disinfectant, failing to eliminate biofilms under all the test conditions.

  16. Identification and methods for prevention of Enterococcus mundtii infection in silkworm larvae, Bombyx mori, reared on artificial diet.

    PubMed

    Nwibo, Don Daniel; Matsumoto, Yasuhiko; Sekimizu, Kazuhisa

    2015-06-01

    Previously, it was reported that Enterococcus mundtii (E. mundtii) was associated with flacherie disease of silkworm larvae reared on artificial diet. In this study, we report that E. mundtii was isolated from diseased silkworm larvae, and validated as a pathogenic bacterium of the animal. When silkworm larva was infected with 1.04 × 10⁶ colony-forming units of E. mundtii via oral administration of diet, half population died within six days, indicating that the bacterium is pathogenic to silkworm. Less severe infection was found to cause anorexia and hamper the development of larvae. This pathogen was found to proliferate in both time- and dose-dependent manner in the gastrointestinal tract of the animal. The bacterium was isolated from powder of artificial diet made from mulberry leaves, and from mulberry leaves growing at a field. Minimum inhibitory concentration determination revealed that this bacterium was susceptible to tested antibiotics. Vancomycin treatment of diet significantly decreased the number of E. mundtii in intestine of silkworm larvae infected with the bacteria, compared to control. Furthermore, autoclaving or gamma ray irradiation of diet was also effective for exclusion of E. mundtii from the diet without the loss of its nutrient capacities. These results suggest that mulberry leaves used in making artificial diet for silkworm larvae is one of the sources of E. mundtii infection; and that antibiotic treatment, autoclaving or gamma ray irradiation of artificial diet can exclude the bacteria.

  17. Identification of vancomycin interaction with Enterococcus faecalis within 30 min of interaction time using Raman spectroscopy.

    PubMed

    Assmann, Cora; Kirchhoff, Johanna; Beleites, Claudia; Hey, Jessica; Kostudis, Sophia; Pfister, Wolfgang; Schlattmann, Peter; Popp, Jürgen; Neugebauer, Ute

    2015-11-01

    Vancomycin is an important glycopeptide antibiotic which is used to treat serious infections caused by Gram-positive bacteria. However, during the last years, a tremendous rise in vancomycin resistances, especially among Enterococci, was reported, making fast diagnostic methods inevitable. In this contribution, we apply Raman spectroscopy to systematically characterize vancomycin-enterococci interactions over a time span of 90 min using a sensitive Enterococcus faecalis strain and two different vancomycin concentrations above the minimal inhibitory concentration (MIC). Successful action of the drug on the pathogen could be observed already after 30 min of interaction time. Characteristic spectral changes are visualized with the help of multivariate statistical analysis (linear discriminant analysis and partial least squares regressions). Those changes were employed to train a statistical model to predict vancomycin treatment based on the Raman spectra. The robustness of the model was tested using data recorded by an independent operator. Classification accuracies of >90 % were obtained for vancomycin concentrations in the lower range of a typical trough serum concentration recommended for most patients during appropriate vancomycin therapy. Characterization of drug-pathogen interactions by means of label-free spectroscopic methods, such as Raman spectroscopy, can provide the knowledge base for innovative and fast susceptibility tests which could speed up microbiological analysis as well as finding applications in novel antibiotic screenings assays. Graphical Abstract E. faecalis is incubated with vancomycin and characterized by means of Raman spectroscopy after different time points. Characteristic spectral changes reveal efficient vancomycin-enterococci-interaction.

  18. Effects of storage temperature on tyramine production by Enterococcus faecalis R612Z1 in water-boiled salted ducks.

    PubMed

    Liu, Fang; Du, Lihui; Wu, Haihong; Wang, Daoying; Zhu, Yongzhi; Geng, Zhiming; Zhang, Muhan; Xu, Weimin

    2014-10-01

    Tyramine production by Enterococcus faecalis R612Z1 in water-boiled salted ducks was evaluated during storage at different temperatures. The results showed that E. faecalis R612Z1 could produce tyramine in meat samples when the storage temperature was no less than 4°C. The E. faecalis R612Z1 counts of the meat samples reached 10(8) CFU/g on day 7 at 4°C and on day 4 at 10°C. However, the tyramine content of the meat samples stored at 10°C increased to 23.73 μg/g (on day 10), which was greater than the level in the samples stored at 4°C (7.56 μg/g). Reverse transcription quantitative PCR detection of the expression level of the tyrDC gene in E. faecalis R612Z1 in the meat samples revealed no significant changes at different storage temperatures. Thus, the changes in tyramine production of E. faecalis R612Z1 may be due to the different enzymatic activities at different storage temperatures.

  19. Enterococcus faecalis Bearing Aggregation Substance Is Resistant to Killing by Human Neutrophils despite Phagocytosis and Neutrophil Activation

    PubMed Central

    Rakita, Robert M.; Vanek, Natalie N.; Jacques-Palaz, Karen; Mee, Mee; Mariscalco, M. Michele; Dunny, Gary M.; Snuggs, Mark; Van Winkle, W. Barry; Simon, Scott I.

    1999-01-01

    Enterococcus faecalis aggregation substance (AS) mediates efficient bacterium-bacterium contact to facilitate plasmid exchange as part of a bacterial sex pheromone system. We have previously determined that AS promotes direct, opsonin-independent binding of E. faecalis to human neutrophils (PMNs) via complement receptor type 3 and other receptors on the PMN surface. We have now examined the functional consequences of this bacterium-host cell interaction. AS-bearing E. faecalis was phagocytosed and internalized by PMNs, as determined by deconvolution fluorescence microscopy. However, these bacteria were not killed by PMNs, and internalized bacteria excluded propidium iodide, indicating intact bacterial membranes. Resistance to killing occurred despite activation of PMNs, as indicated by an increase in both functional and total surface Mac-1 expression, shedding of l-selectin, and an increase in PMN extracellular superoxide and phagosomal oxidant production. Deconvolution fluorescence microscopy also revealed that phagosomes containing AS-bearing bacteria were markedly larger than phagosomes containing opsonized E. faecalis, suggesting that some modification of phagosomal maturation may be involved in AS-induced resistance to killing. PMN phagosomal pH was significantly higher after ingestion of nonopsonized AS-bearing E. faecalis than after that of opsonized bacteria. The novel ability of AS to promote intracellular survival of E. faecalis inside PMNs suggests that AS may be a virulence factor used by strains of E. faecalis. PMID:10531268

  20. Characterization of lead-resistant river isolate Enterococcus faecalis and assessment of its multiple metal and antibiotic resistance.

    PubMed

    Aktan, Yasin; Tan, Sema; Icgen, Bulent

    2013-06-01

    Contamination of surface waters has a direct impact on the public health of entire communities. Microorganisms inhabiting contaminated surface waters have developed mechanisms of coping with a variety of toxic metals and drugs. Investigations were carried out to isolate and identify lead-resistant bacteria from the river Kızılırmak along the city of Kırıkkale, Turkey. Of the 33 lead-resistant isolates, one isolate with a minimal inhibitory concentration of 1,200 mg L(-1) was isolated and identified as Enterococcus faecalis by using biochemical tests and 16S rRNA sequencing. Lead-resistant E. faecalis isolate was found out to be resistant to other heavy metals like aluminum, lithium, barium, chromium, iron, silver, tin, nickel, zinc, and strontium and to drugs like amikacin, aztreonam, and gentamicin. E. faecalis harbored four plasmids with the molecular sizes of 1.58, 3.06, 22.76, and 28.95 kb. Plasmid profile analyses of cured derivatives revealed that the lead resistance ability of E. faecalis was still existing despite the elimination of all the plasmids. Moreover, the antibiotic resistance pattern of the cured derivatives did not demonstrate any change from the parental strain. Our findings indicated that the lead resistance genes of E. faecalis were located on the chromosomal DNA rather than the plasmid.

  1. The recombinase IntA is required for excision of esp-containing ICEEfm1 in Enterococcus faecium.

    PubMed

    Top, Janetta; Sinnige, Jan C; Majoor, Eline A M; Bonten, Marc J M; Willems, Rob J L; van Schaik, Willem

    2011-02-01

    Comparative genome analysis of Enterococcus faecium recently revealed that a genomic island containing the esp gene, referred to as the esp-containing pathogenicity island (esp PAI), can be transferred by conjugation and contains a partial Tn916-like element and an integrase gene, intA. Here, we characterize the role of intA in the excision of the esp PAI. An intA insertion-deletion mutant in E. faecium E1162 (E1162ΔintA) was constructed and in trans complemented with wild-type intA (E1162ΔintA::pEF30). Circular intermediates (CI) of excised esp PAI were determined using inverse PCR analysis on purified chromosomal DNA from strains E1162, E1162Δesp, E1162ΔintA, and E1162ΔintA::pEF30. In E1162 and E1162Δesp, CI of the esp PAI were detected. No CI were detected in E1162ΔintA, while in the complemented strain E1162ΔintA::pEF30 CI formation was restored, indicating that intA is essential for excision and subsequent mobilization of the esp-containing genomic island in E. faecium. Based on the fact that this island can be mobilized and is self-transmissible, we propose to change the name of the esp PAI to ICEEfm1.

  2. Interference in Pheromone-Responsive Conjugation of a High-Level Bacitracin Resistant Enterococcus faecalis Plasmid of Poultry Origin

    PubMed Central

    Tremblay, Cindy-Love; Archambault, Marie

    2013-01-01

    The current study reports on contact interference of a high-level bacitracin- resistant pheromone-responsive plasmid of Enterococcus faecalis strain 543 of poultry origin during conjugative transfer of bcr antimicrobial resistance genes using a polyclonal antiserum aggregation substance44–560 (AS). After induction with pheromones produced by the recipient strain E. faecalis JH2-2, clumping of the donor E. faecalis strain 543 was observed as well as high transfer frequencies of bcr in short time broth mating. Filter mating assays from donor strain E. faecalis 543 to the recipient strain E. faecalis JH2-2 revealed conjugative transfer of asa1 (AS), bcrRAB and traB (negative regulator pheromone response) genes. The presence of these genes in transconjugants was confirmed by antimicrobial susceptibility testing, PCR, Southern hybridization and sequencing. A significant reduction in formation of aggregates was observed when the polyclonal anti-AS44–560 was added in the pheromone-responsive conjugation experiments as compared to the induced state. Moreover, interference of anti-AS44–560 antibodies in pheromone-responsive conjugation was demonstrated by a reduction in horizontal transfer of asa1 and bcr genes between E. faecalis strain 543 and E. faecalis JH2-2. Reducing the pheromone-responsive conjugation of E. faecalis is of interest because of its clinical importance in the horizontal transfer of antimicrobial resistance. PMID:24030654

  3. The Two-Component System GrvRS (EtaRS) Regulates ace Expression in Enterococcus faecalis OG1RF

    PubMed Central

    Singh, Kavindra V.; La Rosa, Sabina Leanti; Cohen, Ana Luisa V.; Murray, Barbara E.

    2014-01-01

    Expression of ace (adhesin to collagen of Enterococcus faecalis), encoding a virulence factor in endocarditis and urinary tract infection models, has been shown to increase under certain conditions, such as in the presence of serum, bile salts, urine, and collagen and at 46°C. However, the mechanism of ace/Ace regulation under different conditions is still unknown. In this study, we identified a two-component regulatory system GrvRS as the main regulator of ace expression under these stress conditions. Using Northern hybridization and β-galactosidase assays of an ace promoter-lacZ fusion, we found transcription of ace to be virtually absent in a grvR deletion mutant under the conditions that increase ace expression in wild-type OG1RF and in the complemented strain. Moreover, a grvR mutant revealed decreased collagen binding and biofilm formation as well as attenuation in a murine urinary tract infection model. Here we show that GrvR plays a major role in control of ace expression and E. faecalis virulence. PMID:25385790

  4. Biochemical and Structural Basis for Inhibition of Enterococcus faecalis Hydroxymethylglutaryl-CoA Synthase, mvaS, by Hymeglusin

    SciTech Connect

    Skaff, D. Andrew; Ramyar, Kasra X.; McWhorter, William J.; Barta, Michael L.; Geisbrecht, Brian V.; Miziorko, Henry M.

    2012-07-25

    Hymeglusin (1233A, F244, L-659-699) is established as a specific {beta}-lactone inhibitor of eukaryotic hydroxymethylglutaryl-CoA synthase (HMGCS). Inhibition results from formation of a thioester adduct to the active site cysteine. In contrast, the effects of hymeglusin on bacterial HMG-CoA synthase, mvaS, have been minimally characterized. Hymeglusin blocks growth of Enterococcus faecalis. After removal of the inhibitor from culture media, a growth curve inflection point at 3.1 h is observed (vs 0.7 h for the uninhibited control). Upon hymeglusin inactivation of purified E. faecalis mvaS, the thioester adduct is more stable than that measured for human HMGCS. Hydroxylamine cleaves the thioester adduct; substantial enzyme activity is restored at a rate that is 8-fold faster for human HMGCS than for mvaS. Structural results explain these differences in enzyme-inhibitor thioester adduct stability and solvent accessibility. The E. faecalis mvaS-hymeglusin cocrystal structure (1.95 {angstrom}) reveals virtually complete occlusion of the bound inhibitor in a narrow tunnel that is largely sequestered from bulk solvent. In contrast, eukaryotic (Brassica juncea) HMGCS binds hymeglusin in a more solvent-exposed cavity.

  5. Addiction toxin Fst has unique effects on chromosome segregation and cell division in Enterococcus faecalis and Bacillus subtilis.

    PubMed

    Patel, S; Weaver, K E

    2006-08-01

    The Fst toxin of the Enterococcus faecalis pAD1-encoded par addiction module functions intracellularly to kill plasmid-free segregants. Previous results had shown that Fst induction results in membrane permeabilization and cessation of macromolecular synthesis, but only after 45 min. Electron micrographs of toxin-induced cells showed no obvious membrane abnormalities but did reveal defects in nucleoid segregation and cell division, begging the question of which is the primary effect of Fst. To distinguish the possibilities, division septae and nucleoids were visualized simultaneously with fluorescent vancomycin and a variety of DNA stains. Results showed that division and segregation defects occurred in some cells within 15 min after induction. At these early time points, affected cells remained resistant to membrane-impermeant DNA stains, suggesting that loss of membrane integrity is a secondary effect caused by ongoing division and/or segregation defects. Fst-resistant mutants showed greater variability in cell length and formed multiple septal rings even in the absence of Fst. Fst induction was also toxic to Bacillus subtilis. In this species, Fst induction caused only minor division abnormalities, but all cells showed a condensation of the nucleoid, suggesting that effects on the structure of the chromosomal DNA might be paramount.

  6. The TIR Domain Containing Locus of Enterococcus faecalis Is Predominant among Urinary Tract Infection Isolates and Downregulates Host Inflammatory Response

    PubMed Central

    Kraemer, Thomas Daniel; Quintanar Haro, Orlando Daniel; Domann, Eugen; Chakraborty, Trinad; Tchatalbachev, Svetlin

    2014-01-01

    Based on Toll/interleukin-1 receptor (TIR) domain structure homology, we detected a previously uncharacterized gene encoding for a TIR domain containing protein (Tcp) in the genome of Enterococcus faecalis. We assigned this gene the name tcpF (as in Tcp of E. faecalis). Screening of E. faecalis samples revealed that tcpF is more common in isolates from urinary tract infections (UTIs) than in human faecal flora. tcpF alleles showed moderate single nucleotide polymorphism (SNP) among UTI isolates. Infection of mouse RAW264.7 macrophages with a tcpF knock-out mutant led to elevated cytokine response compared to the isogenic wild type E. faecalis strain. In silico analysis predicted significant tertiary structure homology to the TIR domain of human TLR1 (TLR1-TIR). When transiently expressed in cultured eukaryotic cells, TcpF caused suppression of TLR2-dependent NF-κB activation suggesting for TcpF a role as a factor in E. faecalis that benefits colonization by modulating the host's immune responses. PMID:25147569

  7. Decolorization and detoxification of sulfonated toxic diazo dye C.I. Direct Red 81 by Enterococcus faecalis YZ 66.

    PubMed

    Sahasrabudhe, Madhuri M; Saratale, Rijuta G; Saratale, Ganesh D; Pathade, Girish R

    2014-01-01

    Isolated Enterococcus faecalis YZ 66 strain shows ability to decolorize various industrial dyes among which, it showed complete decolorization and degradation of toxic, sulfonated recalcitrant diazo dye Direct Red 81 (50 mg/L) within 1.5 h of incubation under static anoxic condition. The optimum pH and temperature for decolorization was 7.0 and 40°C, respectively. Significant induction in the activity of intracellular oxidoreductive enzymes suggested its involvement in the decolorization of Direct Red 81. The biodegradation of Direct Red 81 was monitored by UV-Visible, FT-IR spectroscopy and HPLC. The final products were characterized by GC-MS and possible pathway of the degradation of the dye was proposed. The phytotoxicity assay (with respect to plants Sorghum vulgare and Phaseolus mungo) revealed that the degradation of Direct Red 81 produced nontoxic metabolites. Finally E. faecalis was employed to decolorize actual industrial effluent showing decolorization (in terms of ADMI value) with moderate COD and BOD reduction. Moreover the result increases the applicability of the strain for the treatment of industrial wastewaters containing dye pollutants.

  8. Safety, beneficial and technological properties of Enterococcus faecium isolated from Brazilian cheeses

    PubMed Central

    dos Santos, Karina Maria Olbrich; Vieira, Antônio Diogo Silva; Salles, Hévila Oliveira; Oliveira, Jacqueline da Silva; Rocha, Cíntia Renata Costa; Borges, Maria de Fátima; Bruno, Laura Maria; Franco, Bernadette Dora Gombossy de Melo; Todorov, Svetoslav Dimitrov

    2015-01-01

    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. PMID:26221113

  9. Safety, beneficial and technological properties of Enterococcus faecium isolated from Brazilian cheeses.

    PubMed

    Dos Santos, Karina Maria Olbrich; Vieira, Antônio Diogo Silva; Salles, Hévila Oliveira; Oliveira, Jacqueline da Silva; Rocha, Cíntia Renata Costa; Borges, Maria de Fátima; Bruno, Laura Maria; Franco, Bernadette Dora Gombossy de Melo; Todorov, Svetoslav Dimitrov

    2015-03-01

    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.

  10. Serum cholesterol levels in axenic mice colonized with Enterococcus faecium and Lactobacillus acidophilus.

    PubMed

    Zacconi, C; Bottazzi, V; Rebecchi, A; Bosi, E; Sarra, P G; Tagliaferri, L

    1992-10-01

    Hypocholesterolemic effect was shown in axenic, mono, bicolonized and conventional mice: the effect was different depending on probiotic properties of intestinal microorganisms. Contamination by Enterococcus faecium CX determined the highest effect: haematic cholesterol level decrease was 16.9% in females and 7.8% in males. In mice contaminated by Lactobacillus acidophilus N5 the decrease of haematic cholesterol levels was less and not relevant in mice contaminated by conventional microflora. Enterococcus faecium CX and Lactobacillus acidophilus N5 strains were able to grow in presence of bile salts, to colonize intestinal tract, to survive at gastric conditions and to assimilate cholesterol (E. faecium more than L. acidophilus). The authors consider the possibility to associate probiotic strains with these characteristics for the health of consumers.

  11. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese.

    PubMed

    Martino, Gabriela P; Quintana, Ingrid M; Espariz, Martín; Blancato, Victor S; Gallina Nizo, Gabriel; Esteban, Luis; Magni, Christian

    2016-02-04

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production.

  12. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese

    PubMed Central

    Martino, Gabriela P.; Quintana, Ingrid M.; Espariz, Martín; Blancato, Victor S.; Gallina Nizo, Gabriel; Esteban, Luis

    2016-01-01

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  13. Vancomycin-resistant Enterococcus bacteremia in a child with acute myeloid leukemia: successful treatment with daptomycin.

    PubMed

    Büyükcam, Ayşe; Karadağ Öncel, Eda; Özsürekçi, Yasemin; Cengiz, Ali B; Kuşkonmaz, Barış; Sancak, Banu

    2016-12-01

    Multiple-drug-resistant enterococcal infections canbe a serious problem in pediatric patients particularly concomitance with severe underlying diseases and lead to significant morbidity and mortality. The treatment options in children are limited compared with adults. We report a 3-year old-boy with acute myeloid leukemia (AML)-M7 and vancomycin-resistant enterococcus bacteremia successfully treated with daptomycin. Daptomycin may be an alternative therapy for VRE infections in children; more studies are needed for extended usage.

  14. First case of vanA-positive Enterococcus mundtii in human urinary tract infection in Iran

    PubMed Central

    Sharifi-Rad, M.; Shadanpour, S.; van Belkum, A.; Soltani, A.; Sharifi-Rad, J.

    2016-01-01

    We cultured enterococci from urinary tract infections in Iranian hospitals. Seven different Enterococcus species (E. raffinosus, E. durans, E. hirae, E. avium, E. mundtii, E. faecium and E. faecalis) were found. Seven strains were vancomycin resistant, leading to an overall vancomycin resistance rate of 3.9%. The enterococcal infection rate was high and vancomycin-resistant enterococci incidence low. We report the first vanA-positive E. mundtii urinary tract infections. PMID:27081495

  15. A rare case of Enterococcus faecalis-induced orbital cellulitis and myositis

    PubMed Central

    Kohli, Piyush; Ichhpujani, Parul; Bansal, Rakesh Kumar; Kumar, Suresh

    2016-01-01

    Orbital cellulitis is an infection of soft tissue behind the orbital septum. Common pathogens isolated include Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumoniae. It is a straightforward diagnosis and usually responds to empirical treatment without any sequela. We report a case of orbital cellulitis caused by Enterococcus faecalis, which was complicated by myositis of levator palpebrae superioris. To the best of our knowledge, only one case report exists dating way back to 1986. PMID:27688288

  16. [Antimicrobial susceptibility of Enterococcus faecalis isolated from patients in Córdoba (Spain)].

    PubMed

    Causse, M; Franco-Alvarez de Luna, F; García-Mayorgas, A D; Rodríguez, F C; Casal, M

    2006-06-01

    Enterococcus faecalis is a pathogenic microorganism. The aim of this investigation was to study the antibiotic susceptibility of the strains isolated in Cordoba in a 20-month period (January 2004 to August 2005). Susceptibility rates to betalactamics were 98% to ampicillin and 99% to amoxicillin/clavulanic acid; high-dose aminoglycosides (streptomycin 1000 microg and gentamycin 500 microg) obtained 56% and 76%, respectively. We found no strains resistant to glycopeptides (vancomycin and teicoplanin) or to linezolid.

  17. First record of vancomycin-resistant Enterococcus faecium in Canadian wildlife.

    PubMed

    Oravcova, Veronika; Janecko, Nicol; Ansorge, Antonin; Masarikova, Martina; Literak, Ivan

    2014-06-01

    In this study, we focused on spreading of vancomycin-resistant enterococci (VRE) to the environment. We studied that weather crows in Canada may be carriers and potentially reservoirs of VRE with vanA gene. We have found one multi-resistant isolate of Enterococcus faecium sequence type (ST) 448 with vanA gene on Prince Edward Island. This study is the first report of VRE in Canadian wildlife.

  18. [Antibiotic resistance analysis of Enterococcus spp. and Enterobacteriaceae spp. isolated from food].

    PubMed

    Korotkevich, Yu V

    2016-01-01

    The isolates from foods were screened for sensitivity to clinically significant antibiotics to assess the actual situation related to the prevalence of the antibiotic-resistant microorganisms in food. The goal of this work was to study the phenotypic characteristics of the antibiotic susceptibility of Enterobacteriaceae and Enterococcus spp. isolated from the good quality foods, and evaluation of the prevalence of tetracycline resistance in this groups of microbial contaminants. 68 strains of Enterobacteriaceae family and Enterococcus spp. isolated from poultry and livestock meat, pasteurized dairy products, acquired in the retail in the Moscow region, were studied. The disk-diffusion method (DDM) analysis showed a rather high prevalence of bacteria that are resistant and forming resistance to broad-spectrum antibiotics: in general 38% of Enterobacteriaceae strains and 40% of Enterococcus spp., isolated from meat products were resistant to tetracycline and doxycycline, and 21 and 33% - from dairy products, respectively; 26% of milk isolates and 54% of meat isolates were resistant to ampicillin. Considering that the tetracyclines is the most frequently used in animal husbandry and veterinary, the incidence and levels of tetracycline resistance were evaluated using tests with higher sensitivity to minimum inhibitory concentration (MIC), than the DDM. It was shown that among the Enterobacteriaceae strains 26% of isolates and 38% isolates were highly resistant to tetracycline (MIC ranged from 8 to 120 mg/kg) and 17-40% - among Enterococcus spp. These data obtained on a small number of samples, however, correspond to the frequency of tetracycline resistant strains detected in animal products in the EU (10-50%). Two multidrug-resistant enterobacteria strains - Klebsiella pneumoniae (farmer cheese) and Escherichia coli (minced turkey) were found among the .46 strains (4.4%), and they were resistant to 8 antibiotics.

  19. Dissemination of antibiotic resistant Enterococcus spp. and Escherichia coli from wild birds of Azores Archipelago.

    PubMed

    Santos, Tiago; Silva, Nuno; Igrejas, Gilberto; Rodrigues, Pedro; Micael, Joana; Rodrigues, Tiago; Resendes, Roberto; Gonçalves, Alexandre; Marinho, Catarina; Gonçalves, David; Cunha, Regina; Poeta, Patrícia

    2013-12-01

    Antibiotic-resistant is profoundly important to human and animal health, but the environmental reservoirs of resistance determinants are poorly understood, in particular in wild environments in remote Archipelagos. Moreover, the prevalence of antibiotic-resistant bacteria in wild bird populations is rather unknown. In the present study, we used the Azores Islands as a model study for antimicrobial resistance in a remote Archipelago, and examined the antibiotic resistance profile in enterococci and Escherichia coli recovered from faecal samples of wild birds collected in this Archipelago. A total of 138 enterococci and 115 E. coli isolates were analyzed for resistance to antimicrobial agents. Of the enterococcal isolates, Enterococcus faecalis was the most prevalent detected species (59 isolates), followed by Enterococcus faecium (40 isolates), Enterococcus durans (27 isolates) and Enterococcus hirae (12 isolates). The enterococci strains showed high percentages of resistance to tetracycline (32.6%), to ciprofloxacin (19.6%) and to erythromycin (11.6%). Lower level of resistance (<10%) was detected for ampicillin, chloramphenicol and teicoplanin. One vancomycin-resistant E. faecalis isolate was detected and harbored the vanA resistant gene. Resistance genes detected included tet(M) and/or tet(L), ermB in all tetracycline and erythromycin-resistant isolates. Resistance in E. coli isolates was detected for ampicillin, tetracycline, sulfamethoxazole/trimethoprim, streptomycin, and tobramycin. The blaTEM, aadA, aadA5, strA, strB, tet(A) and/or tet(B), and the intI genes were found in all ampicillin, streptomycin, tetracycline, and sulfamethoxazole/trimethoprim-resistant isolates respectively. The data shown in this study are essential to improve knowledge about the dissemination of resistant strains through wild birds from remote archipelagos such as the Azores Archipelago and the possible implications involved in transferring these resistances either to other animals

  20. Deactivation of Enterococcus Faecalis Bacteria by an Atmospheric Cold Plasma Brush

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Huang, Jun; Du, Ning; Liu, Xiao-Di; Lv, Guo-Hua; Wang, Xing-Quan; Zhang, Guo-Ping; Guo, Li-Hong; Yang, Si-Ze

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed and used to treat enterococcus faecalis bacteria. The results show that the efficiency of the inactivation process by helium plasma is dependent on applied power and exposure time. After plasma treatments, the cell structure and morphology changes can be observed by scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  1. EfaR Is a Major Regulator of Enterococcus faecalis Manganese Transporters and Influences Processes Involved in Host Colonization and Infection

    PubMed Central

    Abrantes, M. C.; Lopes, M. de F.

    2013-01-01

    Metal ions, in particular manganese, are important modulators of bacterial pathogenicity. However, little is known about the role of manganese-dependent proteins in the nosocomial pathogen Enterococcus faecalis, a major cause of bacterial endocarditis. The present study demonstrates that the DtxR/MntR family metalloregulator EfaR of E. faecalis controls the expression of several of its regulon members in a manganese-dependent way. We also show that efaR inactivation impairs the ability of E. faecalis to form biofilms, to survive inside macrophages, and to tolerate oxidative stress. Our results reveal that EfaR is an important modulator of E. faecalis virulence and link manganese homeostasis to enterococcal pathogenicity. PMID:23297382

  2. Functional cloning and expression of emeA, and characterization of EmeA, a multidrug efflux pump from Enterococcus faecalis.

    PubMed

    Lee, Eun-Woo; Chen, Jing; Huda, Md Nazmul; Kuroda, Teruo; Mizushima, Tohru; Tsuchiya, Tomofusa

    2003-02-01

    A fragment of chromosomal DNA from Enterococcus faecalis ATCC 29212 was cloned using Escherichia coli KAM32 host cells lacking major multidrug efflux pumps. E. coli KAM32 cells were sensitive to many antimicrobial agents, and the transformed cells harboring a recombinant plasmid became resistant to several structurally unrelated antimicrobial agents such as tetraphenylphosphonium chloride, 4',6-diamidino-2-phenylindole (DAPI), Hoechst 33342, acriflavine, benzalkonium chloride, norfloxacin and ethidium bromide. This suggests that the cloned DNA fragment carries a gene(s) encoding a multidrug efflux pump. Determination of the nucleotide sequence of the cloned DNA revealed a gene designated as emeA. The transformed E. coli cells showed efflux activity of several antimicrobial agents such as DAPI, Hoechst 33342 and acriflavine. Efflux of DAPI via EmeA was strongly inhibited by reserpine.

  3. Biological Activities of Tetrodotoxin-Producing Enterococcus faecium AD1 Isolated from Puffer Fishes.

    PubMed

    Nguyen, Tu Hoang Khue; Nguyen, Huu Ngoc; Nghe, Dat Van; Nguyen, Kim Hoang

    2015-01-01

    Puffer fishes were collected from the central sea in Vietnam from spring to summer season. The eggs were incubated in MRS broth that was used to test the toxicity in mice and isolate the lactic acid bacteria community that could produce tetrodotoxin (TTX). Thin layer chromatography (TLC) and high performance lipid chromatography (HPLC) were used to detect and quantify TTX. As a result, Enterococcus faecium AD1 which was identified by biochemical test and 16S rRNA analysis could produce TTX 0.3 mg/mL when cultured in MRS broth. The bacterium was optimized for TTX production and gave 0.18 mg/mL, 0.07 mg/mL, and 0.15 mg/mL in media prepared from the meat-washing water of freshwater fishes (Pangasius bocourti, Oreochromis sp.) and sea fish (Auxis thazard), respectively, that are also hopeful to answer some poisoning cases related to eating fishes. Enterococcus faecium also showed the wide antimicrobial activities on yeast, Gram-negative and -positive bacteria. Extracted exopolysaccharide (EPS) that reacted with 2,2-diphenyl-1-picrylhydrazyl to give IC50 at 5 mg/mL equaled 11 mg/mL ascorbic acid which could show effects on Hela-6 and Hep G2 using sulforhodamine B test. Enterococcus faecium can be claimed as a promising source in tetrodotoxin and biological compounds.

  4. Biological Activities of Tetrodotoxin-Producing Enterococcus faecium AD1 Isolated from Puffer Fishes

    PubMed Central

    Nguyen, Tu Hoang Khue; Nguyen, Huu Ngoc; Nghe, Dat Van; Nguyen, Kim Hoang

    2015-01-01

    Puffer fishes were collected from the central sea in Vietnam from spring to summer season. The eggs were incubated in MRS broth that was used to test the toxicity in mice and isolate the lactic acid bacteria community that could produce tetrodotoxin (TTX). Thin layer chromatography (TLC) and high performance lipid chromatography (HPLC) were used to detect and quantify TTX. As a result, Enterococcus faecium AD1 which was identified by biochemical test and 16S rRNA analysis could produce TTX 0.3 mg/mL when cultured in MRS broth. The bacterium was optimized for TTX production and gave 0.18 mg/mL, 0.07 mg/mL, and 0.15 mg/mL in media prepared from the meat-washing water of freshwater fishes (Pangasius bocourti, Oreochromis sp.) and sea fish (Auxis thazard), respectively, that are also hopeful to answer some poisoning cases related to eating fishes. Enterococcus faecium also showed the wide antimicrobial activities on yeast, Gram-negative and -positive bacteria. Extracted exopolysaccharide (EPS) that reacted with 2,2-diphenyl-1-picrylhydrazyl to give IC50 at 5 mg/mL equaled 11 mg/mL ascorbic acid which could show effects on Hela-6 and Hep G2 using sulforhodamine B test. Enterococcus faecium can be claimed as a promising source in tetrodotoxin and biological compounds. PMID:26380310

  5. Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

    PubMed Central

    Borzini, Letizia; Condò, Roberta; De Dominicis, Paolo; Casaglia, Adriano; Cerroni, Loredana

    2016-01-01

    Background: There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues. Objectives: To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis. Method: Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”. Results: Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro. Conclusion: Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space. PMID:28217184

  6. Identification, antimicrobial resistance and genotypic characterization of Enterococcus spp. isolated in Porto Alegre, Brazil

    PubMed Central

    Bender, Eduardo André; de Freitas, Ana Lúcia Peixoto; Reiter, Keli Cristine; Lutz, Larissa; Barth, Afonso Luís

    2009-01-01

    In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital. PMID:24031416

  7. Application of oligonucleotide microarrays for bacterial source tracking of environmental Enterococcus sp. isolates.

    PubMed

    Indest, Karl J; Betts, Kelley; Furey, John S

    2005-04-01

    In an effort towards adapting new and defensible methods for assessing and managing the risk posed by microbial pollution, we evaluated the utility of oligonucleotide microarrays for bacterial source tracking (BST) of environmental Enterococcus sp. isolates derived from various host sources. Current bacterial source tracking approaches rely on various phenotypic and genotypic methods to identify sources of bacterial contamination resulting from point or non-point pollution. For this study Enterococcus sp. isolates originating from deer, bovine, gull, and human sources were examined using microarrays. Isolates were subjected to Box PCR amplification and the resulting amplification products labeled with Cy5. Fluorescent-labeled templates were hybridized to in-house constructed nonamer oligonucleotide microarrays consisting of 198 probes. Microarray hybridization profiles were obtained using the ArrayPro image analysis software. Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were compared for their ability to visually cluster microarray hybridization profiles based on the environmental source from which the Enterococcus sp. isolates originated. The PCA was visually superior at separating origin-specific clusters, even for as few as 3 factors. A Soft Independent Modeling (SIM) classification confirmed the PCA, resulting in zero misclassifications using 5 factors for each class. The implication of these results for the application of random oligonucleotide microarrays for BST is that, given the reproducibility issues, factor-based variable selection such as in PCA and SIM greatly outperforms dendrogram-based similarity measures such as in HCA and K-Nearest Neighbor KNN.

  8. Application of Oligonucleotide Microarrays for Bacterial Source Tracking of Environmental Enterococcus sp. Isolates

    PubMed Central

    Indest, Karl J.; Betts, Kelley; Furey, John S.

    2005-01-01

    In an effort towards adapting new and defensible methods for assessing and managing the risk posed by microbial pollution, we evaluated the utility of oligonucleotide microarrays for bacterial source tracking (BST) of environmental Enterococcus sp. isolates derived from various host sources. Current bacterial source tracking approaches rely on various phenotypic and genotypic methods to identify sources of bacterial contamination resulting from point or non-point pollution. For this study Enterococcus sp. isolates originating from deer, bovine, gull, and human sources were examined using microarrays. Isolates were subjected to Box PCR amplification and the resulting amplification products labeled with Cy5. Fluorescent-labeled templates were hybridized to in-house constructed nonamer oligonucleotide microarrays consisting of 198 probes. Microarray hybridization profiles were obtained using the ArrayPro image analysis software. Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were compared for their ability to visually cluster microarray hybridization profiles based on the environmental source from which the Enterococcus sp. isolates originated. The PCA was visually superior at separating origin-specific clusters, even for as few as 3 factors. A Soft Independent Modeling (SIM) classification confirmed the PCA, resulting in zero misclassifications using 5 factors for each class. The implication of these results for the application of random oligonucleotide microarrays for BST is that, given the reproducibility issues, factor-based variable selection such as in PCA and SIM greatly outperforms dendrogram-based similarity measures such as in HCA and K-Nearest Neighbor KNN. PMID:16705816

  9. Genotypic and phenotypic heterogeneity in Enterococcus isolates from Batzos, a raw goat milk cheese.

    PubMed

    Psoni, L; Kotzamanides, C; Andrighetto, C; Lombardi, A; Tzanetakis, N; Litopoulou-Tzanetaki, E

    2006-05-25

    This study investigated the genotypic and phenotypic diversity in 34 isolates of enterococci obtained during ripening of Batzos cheese from raw goat milk and characterized phenotypically as Enterococcus durans. RAPD-PCR, plasmid profiling and PFGE were used to study the genetic variability and distinguish closely related isolates. Species recognition by means of RAPD-PCR was in agreement with the phenotypic identification for 29 strains. One strain was characterized as Lactococcus lactis subsp. lactis by RAPD-PCR and four strains were grouped with the Enterococcus faecium reference strain. All strains were vancomycin sensitive, while 10 strains showed beta-haemolytic reaction on human blood and the majority of them (88.9%) showed decarboxylase activity on tyramine. All strains exhibited antagonistic activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli and Listeria monocytogenes and the majority inhibited Enterococcus faecalis. Isolates displayed weak acidifying ability and low proteolytic activities when grown in milk for 24h. However, their caseinolytic activity after growth in milk for seven days was significant with preference for alphas-casein degradation.

  10. Enterococcus faecium stimulates human neutrophils via the formyl-peptide receptor 2.

    PubMed

    Bloes, Dominik Alexander; Otto, Michael; Peschel, Andreas; Kretschmer, Dorothee

    2012-01-01

    The human formyl-peptide receptor 2 (FPR2/ALX) senses phenol-soluble modulin (PSM) peptide toxins produced by pathogenic staphylococcal species and plays a crucial role in directing neutrophil influx during staphylococcal infection. However, it has remained unclear if FPR2 responds also to molecules from other bacterial pathogens. Here we analyzed a variety of gram-positive and gram-negative pathogens and found that apart from staphylococci only certain enterococcal strains have the capacity to stimulate FPR2/ALX. Most of the analyzed Enterococcus faecium but only sporadic Enterococcus faecalis strains released FPR2/ALX-stimulating molecules leading to neutrophil calcium ion fluxes, chemotaxis, and complement receptor upregulation. Among ten test strains vancomycin-resistant E. faecium had a significantly higher capacity to stimulate FPR2/ALX than vancomycin-susceptible strains, suggesting an association of strong FPR2/ALX activation with health-care associated strains. The enterococcal FPR2/ALX agonists were found to be peptides or proteins, which appear, however, to be unrelated to staphylococcal PSMs in sequence and physicochemical properties. Enterococci are among the most frequent invasive bacterial pathogens but the basis of enterococcal virulence and immune activation has remained incompletely understood. Our study indicates that previously unrecognized proteinaceous agonists contribute to Enterococcus-host interaction and underscores the importance of FPR2/ALX in host defense against major endogenous bacterial pathogens.

  11. Undomesticated animals as a reservoir of multidrug-resistant Enterococcus in eastern Poland.

    PubMed

    Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Kostruba, Anna

    2014-07-01

    To assess implications for public health we compared the resistance of Enterococcus spp. strains to antibacterial drugs in wild and exotic animals with strains originating in domesticated animals and characterized correlations between Enterococcus species, the source of the isolate, and the degree of resistance to selected antibiotics. All strains, regardless of source, were susceptible to β-lactams, gentamicin, linezolid, and teicoplanin; the highest resistance was to kanamycin, quinupristin, and rifampicin. Thirteen strains from undomesticated animals were resistant to vancomycin, and one strain, from a fox, was resistant to streptomycin (high-dose). Multidrug-resistant strains accounted for 46% of the strains from wild animals and 59% of the strains from an exotic animal (the Russian tortoise; Testudo horsfieldii). Despite the relatively low level of resistance in the strains isolated from wild and exotic animals, the large number of intermediately susceptible strains in these groups is an indication of the evolutionary character of the development of resistance, suggesting that these animals may be potential reservoirs of Enterococcus strains resistant to a wide panel of currently used antibiotics.

  12. High genetic diversity of Enterococcus faecium and Enterococcus faecalis clinical isolates by pulsed-field gel electrophoresis and multilocus sequence typing from a hospital in Malaysia.

    PubMed

    Weng, Poh Leng; Ramli, Ramliza; Shamsudin, Mariana Nor; Cheah, Yoke-Kqueen; Hamat, Rukman Awang

    2013-01-01

    Little is known on the genetic relatedness and potential dissemination of particular enterococcal clones in Malaysia. We studied the antibiotic susceptibility profiles of Enterococcus faecium and Enterococcus faecalis and subjected them to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). E. faecium and E. faecalis displayed 27 and 30 pulsotypes, respectively, and 10 representative E. faecium and E. faecalis isolates (five each) yielded few different sequence types (STs): ST17 (2 isolates), ST78, ST203, and ST601 for E. faecium, and ST6, ST16, ST28, ST179, and ST399 for E. faecalis. Resistance to tazobactam-piperacillin and ampicillin amongst E. faecium isolates was highly observed as compared to E. faecalis isolates. All of the isolates were sensitive to vancomycin and teicoplanin. The presence of epidemic and nosocomial strains of selected E. faecium STs: 17, 78, and 203 and E. faecalis ST6 as well as high rates of resistance to multiple antibiotics amongst E. faecium isolates is of a particular concern.

  13. High-level aminoglycoside resistance in Enterococcus faecalis and Enterococcus faecium causing invasive infection: Twelve-year surveillance in the Minami Ibaraki Area.

    PubMed

    Osuka, Hanako; Nakajima, Jun; Oishi, Tsuyoshi; Funayama, Yasunori; Ebihara, Tsugio; Ishikawa, Hiroichi; Saito, Kazuto; Koganemaru, Hiroshi; Hitomi, Shigemi

    2016-01-01

    We examined prevalence of high-level aminoglycoside resistance (HLAR) in Enterococcus faecalis and Enterococcus faecium causing invasive infection in the Minami Ibaraki Area. Ten strains of both species each, recovered from the blood or the cerebrospinal fluid between 2003 and 2014, were randomly selected every year. High-level resistance to gentamicin (HLR-GM) and streptomycin (HLR-SM) was detected in 34% (41 of 120 strains) and 18% (21) of E. faecalis and 9% (11) and 39% (48) of E. faecium, respectively. In comparisons of the proportions among three four-year periods, HLR-SM among E. faecium was significantly lower in the 2011-2014 period. All strains with HLR-GM were positive for the aac(6')-Ie-aph(2″)-Ia gene. The ant(6')-Ia gene was detected in all with HLR-SM except for one E. faecalis strain. The present study showed that prevalence of HLR-GM among E. faecalis and E. faecium causing invasive infection in this area was nearly equivalent to that described in previous studies in Japan and that proportions of strains with HLAR did not vary during the study period except for that of HLR-SM among E. faecium.

  14. MALDI-TOF mass spectrometry as a useful tool for identification of Enterococcus spp. from wild birds and differentiation of closely related species.

    PubMed

    Stępień-Pyśniak, Dagmara; Hauschild, Tomasz; Różański, Paweł; Marek, Agnieszka

    2017-03-13

    The aim of this study was to explore the accuracy and feasibility of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in identifying bacteria from environmental sources, as compared to rpoA gene sequencing, and to evaluate the occurrence of bacteria of the genus Enterococcus in wild birds. In addition, a phyloproteomic analysis of certain Enterococcus species with spectral relationships was performed. The enterococci were isolated from 25 species of wild birds in central Europe (Poland). Proteomic (MALDI-TOF MS) and genomic (rpoA gene sequencing) methods were used to identify isolates. Using MALDI-TOF MS, all 54 (100%) isolates were identified as Enterococcus spp. Among these, 51 (94.4%) isolates were identified to the species level - log(score) > or =2.0, and three isolates (5.6%) were identified at a level of probable genus identification - log(score) 1.88-1.927. Phylogenetic analysis based on rpoA sequences confirmed that all enterococci had been correctly identified. Enterococcus faecalis was the most prevalent enterococcal species (50%) and Enterococcus faecium (33.3%) the second most frequent species, followed by Enterococcus hirae (9.3%), Enterococcus durans (3.7%) and Enterococcus casseliflavus (3.7%). The phyloproteomic analysis of the spectral profiles of the isolates showed that MALDI-TOF MS is able to differentiate among similar species of the genus Enterococcus.

  15. [Investigation of the efficacy of some disinfectants against nosocomial Staphylococcus aureus and Enterococcus spp. isolates].

    PubMed

    Eryılmaz, Müjde; Akın, Ahmet; Arıkan Akan, Ozay

    2011-07-01

    Nosocomial infections which exhibit an increasing trend worldwide, are important contributors to morbidity and mortality. Most bacteria that cause nosocomial infections can retain their viability even after exposure to disinfectants in routine practice. This study was conducted to determine the susceptibilities of nosocomial Staphylococcus aureus and Enterococcus spp. isolates to various disinfectants. A total of 30 S.aureus [16 were methicillin-resistant (MRSA), 14 were methicillin-susceptible (MSSA)] and 21 Enterococcus spp. (13 E.faecalis, 7 E.faecium, 1 non-typable Enterococcus spp.) strains isolated from clinical samples of hospitalized patients as nosocomial infection agents in the Central Microbiology Laboratory of Ibn-i Sina Hospital, Ankara University, Faculty of Medicine, were included in the study. Glutaraldehyde (2% wt/vol), chlorhexidine gluconate (4% wt/vol), 2-propanol (70% vol/vol), povidone iodine (7.5% wt/vol), povidone iodine (10% wt/vol) and hydrogen peroxide (3% wt/vol) susceptibilities of the isolates were investigated by quantitative suspension test at contact times of 3, 5, and 10 minutes. All of the isolates were found susceptible to glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone iodine (10%) and 2-propanol (70%) at all tested contact times. However, 12 S.aureus (5 MSSA, 7 MRSA) and 3 enterococci (2 E.faecium, 1 E.faecalis) isolates were found susceptible to hydrogen peroxide (3%) at 3 minutes contact time; 11 S.aureus (4 MSSA, 7 MRSA) and 7 E.faecalis isolates were found susceptible at 5 minutes contact time, and 6 S.aureus (4 MSSA, 2 MRSA) and 3 enterococci (1 E.faecium, 2 E.faecalis) isolates were found susceptible at 10 minutes contact time. One MSSA and 8 enterococci (4 E.faecium, 3 E.faecalis, 1 Enterococcus spp.) isolates were found resistant to hydrogen peroxide (3%) at 10 minutes contact time. In conclusion, glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone

  16. Evaluation of the quality of coastal bathing waters in Spain through fecal bacteria Escherichia coli and Enterococcus.

    PubMed

    Aragonés, L; López, I; Palazón, A; López-Úbeda, R; García, C

    2016-10-01

    Sun. and beach tourism is very important to the economy of Spain, so the control of the quality of the environment on the beaches is essential. Therefore, the analysis and control of the quality of bathing water is necessary, which is defined by the European Directive 2006/7/EC as excellent, good or sufficient depending on the presence of microbiological contamination or other organisms or waste presenting a risk to bathers' health. For that, 1392 beaches of the Iberian Peninsula and its islands were analysed, taking into account: fecal bacteria (Escherichia coli and Enterococcus), physical characteristics of sediment, level of urbanization, climatic and anthropogenic factors, and maritime climate. Thus, it was observed that urban sand beaches located in seas with fewer hours of sunshine and important tide have higher concentrations of E. coli and Enterococcus. There is also an indirect relationship between these microorganisms with salinity (R(2) 0.746 for E. coli and 0.606 for Enterococcus), temperature (R(2) 0.743 for E. coli and 0.604 for Enterococcus) and hours of sunshine (R(2) 0.781 for E. coli and 0.706 for Enterococcus), while this relationship is direct with rainfall (R(2) 0.640 for E. coli and 0.607 for Enterococcus) or wave height (R(2) 0.769 for E. coli and 0.601 for Enterococcus). From all this, it follows that the Directive 2006/7/EC should define more specific criteria as to the place and time of sampling, and take into account the different environment variables that influence the survival of bacteria, so that the results may reflect reality, and avoid staff responsible for sampling freely choose the place and time of sampling.

  17. A decade of genomic history for healthcare-associated Enterococcus faecium in the United Kingdom and Ireland

    PubMed Central

    Raven, Kathy E.; Reuter, Sandra; Reynolds, Rosy; Brodrick, Hayley J.; Russell, Julie E.; Török, M. Estée; Parkhill, Julian; Peacock, Sharon J.

    2016-01-01

    Vancomycin-resistant Enterococcus faecium (VREfm) is an important cause of healthcare-associated infections worldwide. We undertook whole-genome sequencing (WGS) of 495 E. faecium bloodstream isolates from 2001–2011 in the United Kingdom and Ireland (UK&I) and 11 E. faecium isolates from a reference collection. Comparison between WGS and multilocus sequence typing (MLST) identified major discrepancies for 17% of isolates, with multiple instances of the same sequence type (ST) being located in genetically distant positions in the WGS tree. This confirms that WGS is superior to MLST for evolutionary analyses and is more accurate than current typing methods used during outbreak investigations. E. faecium has been categorized as belonging to three clades (Clades A1, hospital-associated; A2, animal-associated; and B, community-associated). Phylogenetic analysis of our isolates replicated the distinction between Clade A (97% of isolates) and Clade B but did not support the subdivision of Clade A into Clade A1 and A2. Phylogeographic analyses revealed that Clade A had been introduced multiple times into each hospital referral network or country, indicating frequent movement of E. faecium between regions that rarely share hospital patients. Numerous genetic clusters contained highly related vanA-positive and -negative E. faecium, which implies that control of vancomycin-resistant enterococci (VRE) in hospitals also requires consideration of vancomycin-susceptible E. faecium. Our findings reveal the evolution and dissemination of hospital-associated E. faecium in the UK&I and provide evidence for WGS as an instrument for infection control. PMID:27527616

  18. Secondary Cell Wall Polymers of Enterococcus faecalis Are Critical for Resistance to Complement Activation via Mannose-binding Lectin*

    PubMed Central

    Geiss-Liebisch, Stefan; Rooijakkers, Suzan H. M.; Beczala, Agnieszka; Sanchez-Carballo, Patricia; Kruszynska, Karolina; Repp, Christian; Sakinc, Tuerkan; Vinogradov, Evgeny; Holst, Otto; Huebner, Johannes; Theilacker, Christian

    2012-01-01

    The complement system is part of our first line of defense against invading pathogens. The strategies used by Enterococcus faecalis to evade recognition by human complement are incompletely understood. In this study, we identified an insertional mutant of the wall teichoic acid (WTA) synthesis gene tagB in E. faecalis V583 that exhibited an increased susceptibility to complement-mediated killing by neutrophils. Further analysis revealed that increased killing of the mutant was due to a higher rate of phagocytosis by neutrophils, which correlated with higher C3b deposition on the bacterial surface. Our studies indicated that complement activation via the lectin pathway was much stronger on the tagB mutant compared with wild type. In concordance, we found an increased binding of the key lectin pathway components mannose-binding lectin and mannose-binding lectin-associated serine protease-2 (MASP-2) on the mutant. To understand the mechanism of lectin pathway inhibition by E. faecalis, we purified and characterized cell wall carbohydrates of E. faecalis wild type and V583ΔtagB. NMR analysis revealed that the mutant strain lacked two WTAs with a repeating unit of →6)[α-l-Rhap-(1→3)]β-d-GalpNAc-(1→5)-Rbo-1-P and →6) β-d-Glcp-(1→3) [α-d-Glcp-(1→4)]-β-d-GalpNAc-(1→5)-Rbo-1-P→, respectively (Rbo, ribitol). In addition, compositional changes in the enterococcal rhamnopolysaccharide were noticed. Our study indicates that in E. faecalis, modification of peptidoglycan by secondary cell wall polymers is critical to evade recognition by the complement system. PMID:22908219

  19. Native Microbial Colonization of Drosophila melanogaster and Its Use as a Model of Enterococcus faecalis Pathogenesis▿ †

    PubMed Central

    Cox, Christopher R.; Gilmore, Michael S.

    2007-01-01

    Enterococci are commensal organisms of the gastrointestinal (GI) tracts of a broad range of mammalian and insect hosts, but they are also leading causes of nosocomial infection. Little is known about the ecological role of enterococci in the GI tract consortia. To develop a tractable model for studying the roles of these organisms as commensals and pathogens, we characterized the Drosophila melanogaster microflora and examined the occurrence of enterococci in the gastrointestinal consortium of Drosophila. In a survey of laboratory-reared Drosophila and wild-captured flies, we found that Drosophila was naturally colonized by representatives of five bacterial phyla. Among these organisms were several species of enterococci, including Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinaraum, and Enterococcus durans, as well as a previously detected but uncultured Enterococcus species. Drosophila could be cured of enterococcal carriage by antibiotic treatment and could be reassociated with laboratory strains. High-level colonization by a well-characterized strain expressing the enterococcal cytolysin was found to be detrimental to Drosophila compared to the effect of an isogenic, noncytolytic control. The anatomical distribution of enterococci in the Drosophila GI tract was determined by immunohistochemical staining of thin sections of naturally colonized and reassociated flies. PMID:17220307

  20. Molecular analysis and distribution of multidrug-resistant Enterococcus faecium isolates belonging to clonal complex 17 in a tertiary care center in Mexico City

    PubMed Central

    2013-01-01

    Background Enterococcus faecium has recently emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. A high rate of resistance to different antibiotics has been associated with virulent clonal complex 17 isolates carrying the esp and hyl genes and the purK1 allele. Results Twelve clinical vancomycin-resistant Enterococcus faecium (VREF) isolates were obtained from pediatric patients at the Hospital Infantil de México Federico Gómez (HIMFG). Among these VREF isolates, 58.3% (7/12) were recovered from urine, while 41.7% (5/12) were recovered from the bloodstream. The VREF isolates showed a 100% rate of resistance to ampicillin, amoxicillin-clavulanate, ciprofloxacin, clindamycin, chloramphenicol, streptomycin, gentamicin, rifampicin, erythromycin and teicoplanin. In addition, 16.7% (2/12) of the isolates were resistant to linezolid, and 66.7% (8/12) were resistant to tetracycline and doxycycline. PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates, esp in 83.3% (10/12) of the isolates and hyl in 50% (6/12) of the isolates. Phylogenetic analysis via molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and demonstrated 44% similarity among the VREF isolates. MLST analysis identified four different sequence types (ST412, ST757, ST203 and ST612). Conclusion This study provides the first report of multidrug-resistant VREF isolates belonging to clonal complex 17 from a tertiary care center in Mexico City. Multidrug resistance and genetic determinants of virulence confer advantages among VREF in the colonization of their host. Therefore, the prevention and control of the spread of nosocomial infections caused by VREF is crucial for identifying new emergent subclones that could be challenging to treat in subsequent years. PMID:24330424

  1. Evaluation of a novel chromogenic agar medium for isolation and differentiation of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis isolates.

    PubMed

    Ledeboer, Nathan A; Das, Kingshuk; Eveland, Michael; Roger-Dalbert, Céline; Mailler, Sandrine; Chatellier, Sonia; Dunne, William Michael

    2007-05-01

    The development of reliable and rapid methods for the identification of patients colonized with vancomycin-resistant enterococci (VRE) is central to the containment of this agent within a hospital environment. To this end, we evaluated a prototype chromogenic agar medium (VRE-BMX; bioMérieux, Marcy l'Etoile, France) used to recover VRE from clinical specimens. This medium can also identify isolated colonies as either vancomycin-resistant Enterococcus faecium or Enterococcus faecalis, based on distinct colony colors. We compared the performance of VRE-BMX with bile esculin azide agar supplemented with vancomycin (BEAV). For this study, 147 stool samples were plated on each test medium and examined after 24 and 48 h of incubation. At 24 h, the sensitivity and specificity of each medium were as follows: BEAV, 90.9% and 89.9%, respectively; VRE-BMX, 96.4% and 96.6%, respectively. The positive predictive values (PPV) of VRE-BMX and BEAV at 24 h were 89.8% and 80.7%, respectively. VRE-BMX provided the identification of 10 isolates of vancomycin-resistant E. faecalis and 4 isolates of vancomycin-resistant E. faecium that were not recovered by BEAV. Further, VRE-BMX was capable of identifying patients colonized with both E. faecium and E. faecalis, a feature useful for infection control purposes that is not a function of BEAV. In terms of the recovery of vancomycin-resistant E. faecium and E. faecalis, the sensitivity and PPV were as follows: BEAV, 75.7% and 74.6%, respectively; VRE-BMX, 95.5% and 91.3%, respectively. In this initial evaluation, we found that VRE-BMX provided improved recovery of VRE from stool specimens, with the added advantage of being able to differentiate between vancomycin-resistant E. faecalis and E. faecium. Extending the incubation period beyond 24 h did not significantly improve the recovery of VRE and resulted in decreased specificity.

  2. β-Lactams Enhance Daptomycin Activity against Vancomycin-Resistant Enterococcus faecalis and Enterococcus faecium in In Vitro Pharmacokinetic/Pharmacodynamic Models

    PubMed Central

    Smith, Jordan R.; Barber, Katie E.; Raut, Animesh

    2015-01-01

    Enterococcus faecalis and Enterococcus faecium are frequently resistant to vancomycin and β-lactams. In enterococcal infections with reduced glycopeptide susceptibility, combination therapy is often administered. Our objective was to conduct pharmacokinetic/pharmacodynamic (PK/PD) models to evaluate β-lactam synergy with daptomycin (DAP) against resistant enterococci. One E. faecalis strain (R6981) and two E. faecium strains (R6370 and 8019) were evaluated. DAP MICs were obtained. All strains were evaluated for response to LL37, an antimicrobial peptide, in the presence and absence of ceftaroline (CPT), ertapenem (ERT), and ampicillin (AMP). After 96 h, in vitro models were run simulating 10 mg DAP/kg body weight/day, 600 mg CPT every 8 h (q8h), 2 g AMP q4h, and 1 g ERT q24h, both alone and in combination against all strains. DAP MICs were 2, 4, and 4 μg/ml for strains R6981, R6370, and 8019, respectively. PK/PD models demonstrated bactericidal activity with DAP-CPT, DAP-AMP, and DAP-ERT combinations against strain 8019 (P < 0.001 and log10 CFU/ml reduction of >2 compared to any single agent). Against strains R6981 and R6370, the DAP-AMP combination demonstrated enhancement against R6370 but not R6981, while the combinations of DAP-CPT and DAP-ERT were bactericidal, demonstrated enhancement, and were statistically superior to all other regimens at 96 h (P < 0.001) against both strains. CPT, ERT, and AMP similarly augmented LL37 killing against strain 8019. In strains R6981 and R6370, CPT and ERT aided LL37 more than AMP (P < 0.001). Compared to DAP alone, combination regimens provide better killing and prevent resistance. Clinical research involving DAP combinations is warranted. PMID:25753639

  3. Mortality in Kittens Is Associated with a Shift in Ileum Mucosa-Associated Enterococci from Enterococcus hirae to Biofilm-Forming Enterococcus faecalis and Adherent Escherichia coli

    PubMed Central

    Ghosh, Anuradha; Borst, Luke; Stauffer, Stephen H.; Suyemoto, Mitsu; Moisan, Peter; Zurek, Ludek

    2013-01-01

    Approximately 15% of foster kittens die before 8 weeks of age, with most of these kittens demonstrating clinical signs or postmortem evidence of enteritis. While a specific cause of enteritis is not determined in most cases, these kittens are often empirically administered probiotics that contain enterococci. The enterococci are members of the commensal intestinal microbiota but also can function as opportunistic pathogens. Given the complicated role of enterococci in health and disease, it would be valuable to better understand what constitutes a “healthy” enterococcal community in these kittens and how this microbiota is impacted by severe illness. In this study, we characterized the ileum mucosa-associated enterococcal community of 50 apparently healthy and 50 terminally ill foster kittens. In healthy kittens, Enterococcus hirae was the most common species of ileum mucosa-associated enterococci and was often observed to adhere extensively to the small intestinal epithelium. These E. hirae isolates generally lacked virulence traits. In contrast, non-E. hirae enterococci, notably Enterococcus faecalis, were more commonly isolated from the ileum mucosa of kittens with terminal illness. Isolates of E. faecalis had numerous virulence traits and multiple antimicrobial resistances. Moreover, the attachment of Escherichia coli to the intestinal epithelium was significantly associated with terminal illness and was not observed in any kitten with adherent E. hirae. These findings identify a significant difference in the species of enterococci cultured from the ileum mucosa of kittens with terminal illness compared to the species cultured from healthy kittens. In contrast to prior case studies that associated enteroadherent E. hirae with diarrhea in young animals, these controlled studies identified E. hirae as more often isolated from healthy kittens and adherence of E. hirae as more common and extensive in healthy kittens than in sick kittens. PMID:23966487

  4. Mortality in kittens is associated with a shift in ileum mucosa-associated enterococci from Enterococcus hirae to biofilm-forming Enterococcus faecalis and adherent Escherichia coli.

    PubMed

    Ghosh, Anuradha; Borst, Luke; Stauffer, Stephen H; Suyemoto, Mitsu; Moisan, Peter; Zurek, Ludek; Gookin, Jody L

    2013-11-01

    Approximately 15% of foster kittens die before 8 weeks of age, with most of these kittens demonstrating clinical signs or postmortem evidence of enteritis. While a specific cause of enteritis is not determined in most cases, these kittens are often empirically administered probiotics that contain enterococci. The enterococci are members of the commensal intestinal microbiota but also can function as opportunistic pathogens. Given the complicated role of enterococci in health and disease, it would be valuable to better understand what constitutes a "healthy" enterococcal community in these kittens and how this microbiota is impacted by severe illness. In this study, we characterized the ileum mucosa-associated enterococcal community of 50 apparently healthy and 50 terminally ill foster kittens. In healthy kittens, Enterococcus hirae was the most common species of ileum mucosa-associated enterococci and was often observed to adhere extensively to the small intestinal epithelium. These E. hirae isolates generally lacked virulence traits. In contrast, non-E. hirae enterococci, notably Enterococcus faecalis, were more commonly isolated from the ileum mucosa of kittens with terminal illness. Isolates of E. faecalis had numerous virulence traits and multiple antimicrobial resistances. Moreover, the attachment of Escherichia coli to the intestinal epithelium was significantly associated with terminal illness and was not observed in any kitten with adherent E. hirae. These findings identify a significant difference in the species of enterococci cultured from the ileum mucosa of kittens with terminal illness compared to the species cultured from healthy kittens. In contrast to prior case studies that associated enteroadherent E. hirae with diarrhea in young animals, these controlled studies identified E. hirae as more often isolated from healthy kittens and adherence of E. hirae as more common and extensive in healthy kittens than in sick kittens.

  5. Inducer bacteria, unique signal peptides and low nutrient media stimulate in-vitro bacteriocin production by Lactobacillus spp. and Enterococcus spp. strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriocins (BCN) provide promising potential to control bacterial infections in a variety of applications. We previously reported three Type IIa BCN produced by Lactobacillus salivarius B-30514 (OR-7), Enterococcus durans/faecium/hirae B-30745 (E 760) and Enterococcus faecium B-30746 (E 50-52). ...

  6. Diversity, distribution and antibiotic resistance of Enterococcus spp. recovered from tomatoes, leaves, water and soil on U.S. Mid-Atlantic farms.

    PubMed

    Micallef, Shirley A; Goldstein, Rachel E Rosenberg; George, Ashish; Ewing, Laura; Tall, Ben D; Boyer, Marc S; Joseph, Sam W; Sapkota, Amy R

    2013-12-01

    Antibiotic-resistant enterococci are important opportunistic pathogens and have been recovered from retail tomatoes. However, it is unclear where and how tomatoes are contaminated along the farm-to-fork continuum. Specifically, the degree of pre-harvest contamination with enterococci is unknown. We evaluated the prevalence, diversity and antimicrobial susceptibilities of enterococci collected from tomato farms in the Mid-Atlantic United States. Tomatoes, leaves, groundwater, pond water, irrigation ditch water, and soil were sampled and tested for enterococci using standard methods. Antimicrobial susceptibility testing was performed using the Sensititre microbroth dilution system. Enterococcus faecalis isolates were characterized using amplified fragment length polymorphism to assess dispersal potential. Enterococci (n = 307) occurred in all habitats and colonization of tomatoes was common. Seven species were identified: Enterococcus casseliflavus, E. faecalis, Enterococcus gallinarum, Enterococcus faecium, Enterococcus avis, Enterococcus hirae and Enterococcus raffinosus. E. casseliflavus predominated in soil and on tomatoes and leaves, and E. faecalis predominated in pond water. On plants, distance from the ground influenced presence of enterococci. E. faecalis from samples within a farm were more closely related than those from samples between farms. Resistance to rifampicin, quinupristin/dalfopristin, ciprofloxacin and levofloxacin was prevalent. Consumption of raw tomatoes as a potential exposure risk for antibiotic-resistant Enterococcus spp. deserves further attention.

  7. First Report of the Multidrug Resistance Gene cfr in Enterococcus faecalis of Animal Origin

    PubMed Central

    Liu, Yang; Wang, Yang; Wu, Congming; Shen, Zhangqi; Schwarz, Stefan; Du, Xiang-Dang; Dai, Lei; Zhang, Wanjiang

    2012-01-01

    The multiresistance gene cfr was identified for the first time in an Enterococcus faecalis isolate of animal origin. The 32,388-bp plasmid pEF-01, which carried the cfr gene, was sequenced completely. Three copies of the insertion sequence IS1216 were identified in pEF-01, and the detection of a cfr- and IS1216-containing amplicon by inverse PCR suggests that IS1216 may play a role in the dissemination of cfr by a recombination process. PMID:22203597

  8. Efficacy of Ceftobiprole Medocaril against Enterococcus faecalis in a Murine Urinary Tract Infection Model

    PubMed Central

    Murray, Barbara E.

    2012-01-01

    We evaluated ceftobiprole against the well-characterized Enterococcus faecalis strain OG1RF (with and without the β-lactamase [Bla] plasmid pBEM10) in a murine urinary tract infection (UTI) model. Ceftobiprole was equally effective for Bla+ and Bla− OG1 strains, while ampicillin was moderately to markedly (depending on the inoculum) less effective against Bla+ than Bla− OG1 strains. These data illustrate an in vivo effect on ampicillin of Bla production by E. faecalis and the stability and efficacy of ceftobiprole in experimental UTI. PMID:22450988

  9. VanE-type vancomycin-resistant Enterococcus faecalis clinical isolates from Australia.

    PubMed

    Abadía-Patiño, Lorena; Christiansen, Keryn; Bell, Jan; Courvalin, Patrice; Périchon, Bruno

    2004-12-01

    Three distinct Enterococcus faecalis VanE-type isolates-BM4574, BM4575, and BM4576-obtained in Australia were studied. Expression of the resistance genes was constitutive in BM4575, probably due to a 2-bp deletion into the vanSE gene, and inducible in BM4574 and BM4576. Transcription analysis of the vanE operons suggested that the five genes were cotranscribed from an initiation site located 25 bp upstream from the ATG start codon of vanE.

  10. Acute Pyelonephritis with Bacteremia Caused by Enterococcus hirae: A Rare Infection in Humans

    PubMed Central

    Pãosinho, Ana; Azevedo, Telma; Alves, João V.; Costa, Isabel A.; Carvalho, Gustavo; Peres, Susana R.; Baptista, Teresa; Borges, Fernando; Mansinho, Kamal

    2016-01-01

    Enterococci are one of the usual residents of the microflora in humans. In the last decade this genus has been reported as the third most common cause of bacteremia. We present the case of a 78-year-old female who was admitted to the emergency room because of nausea, lipothymia, and weakness. She was diagnosed with a pyelonephritis with bacteremia, with the isolation in blood and urine cultures of Escherichia coli and Enterococcus hirae. This last microorganism is a rarely isolated pathogen in humans. Currently it is estimated to represent 1–3% of all enterococcal species isolated in clinical practice. PMID:27127665

  11. Intrathecal/Intraventricular Linezolid in Multidrug-Resistant Enterococcus faecalis Ventriculitis

    PubMed Central

    Lich, Brian F.; Conner, Andrew K.; Burks, Joshua D.; Glenn, Chad A.; Sughrue, Michael E.

    2016-01-01

    Background The use of intrathecal antibiotic therapy for the treatment of ventriculitis and/or meningitis has demonstrated efficacy especially when sterilization of the cerebrospinal fluid is not possible with intravenous antibiotics alone. Case Description We describe the successful treatment of Enterococcus faecalis ventriculitis utilizing intrathecal linezolid in a 32-year-old female patient with severe allergy to vancomycin, prohibitive bacterial susceptibilities, and failure of previous attempts to sterilize the cerebrospinal fluid despite multimodal treatment. Conclusion Intrathecal linezolid is a useful treatment in the setting of multidrug-resistant bacterial ventriculitis. We present a useful dosing regimen for the administration of intrathecal linezolid. PMID:27867829

  12. Outbreak of mastitis in sheep caused by multi-drug resistant Enterococcus faecalis in Sardinia, Italy.

    PubMed

    Sanciu, G; Marogna, G; Paglietti, B; Cappuccinelli, P; Leori, G; Rappelli, P

    2013-03-01

    An outbreak of infective mastitis due to Enterococcus faecalis occurred in an intensive sheep farm in north Sardinia (Italy). E. faecalis, which is only rarely isolated from sheep milk, was unexpectedly found in 22·3% of positive samples at microbiological examination. Forty-five out of the 48 E. faecalis isolates showed the same multi-drug resistance pattern (cloxacillin, streptomycin, kanamycin, clindamycin, oxytetracycline). E. faecalis isolates were analysed by pulsed-field gel electrophoresis, and all 45 multi-drug resistant strains showed an indistinguishable macrorestiction profile, indicating their clonal origin. To our knowledge, this is the first report of an outbreak of mastitis in sheep caused by E. faecalis.

  13. Genomic confirmation of vancomycin-resistant Enterococcus transmission from deceased donor to liver transplant recipient.

    PubMed

    Bashir, Ali; Attie, Oliver; Sullivan, Mitchell; Sebra, Robert; Singh, Kavindra V; Altman, Deena; Pak, Theodore; Dutta, Jayeeta; Chacko, Kieran; Webster, Elizabeth; Lewis, Martha; Hamula, Camille; Delli Carpini, Kristin W; Murray, Barbara E; Kasarskis, Andrew; van Bakel, Harm; Huprikar, Shirish

    2017-01-01

    In a liver transplant recipient with vancomycin-resistant Enterococcus (VRE) surgical site and bloodstream infection, a combination of pulsed-field gel electrophoresis, multilocus sequence typing, and whole genome sequencing identified that donor and recipient VRE isolates were highly similar when compared to time-matched hospital isolates. Comparison of de novo assembled isolate genomes was highly suggestive of transplant transmission rather than hospital-acquired transmission and also identified subtle internal rearrangements between donor and recipient missed by other genomic approaches. Given the improved resolution, whole-genome assembly of pathogen genomes is likely to become an essential tool for investigation of potential organ transplant transmissions.

  14. Genomic confirmation of vancomycin-resistant Enterococcus transmission from deceased donor to liver transplant recipient

    PubMed Central

    Attie, Oliver; Sullivan, Mitchell; Sebra, Robert; Singh, Kavindra V.; Altman, Deena; Pak, Theodore; Dutta, Jayeeta; Chacko, Kieran; Webster, Elizabeth; Lewis, Martha; Hamula, Camille; Delli Carpini, Kristin W.; Murray, Barbara E.; Kasarskis, Andrew; van Bakel, Harm; Huprikar, Shirish

    2017-01-01

    In a liver transplant recipient with vancomycin-resistant Enterococcus (VRE) surgical site and bloodstream infection, a combination of pulsed-field gel electrophoresis, multilocus sequence typing, and whole genome sequencing identified that donor and recipient VRE isolates were highly similar when compared to time-matched hospital isolates. Comparison of de novo assembled isolate genomes was highly suggestive of transplant transmission rather than hospital-acquired transmission and also identified subtle internal rearrangements between donor and recipient missed by other genomic approaches. Given the improved resolution, whole-genome assembly of pathogen genomes is likely to become an essential tool for investigation of potential organ transplant transmissions. PMID:28301471

  15. Riboflavin-shuttled extracellular electron transfer from Enterococcus faecalis to electrodes in microbial fuel cells.

    PubMed

    Zhang, Enren; Cai, Yamin; Luo, Yue; Piao, Zhe

    2014-11-01

    Great attention has been focused on Gram-negative bacteria in the application of microbial fuel cells. In this study, the Gram-positive bacterium Enterococcus faecalis was employed in microbial fuel cells. Bacterial biofilms formed by E. faecalis ZER6 were investigated with respect to electricity production through the riboflavin-shuttled extracellular electron transfer. Trace riboflavin was shown to be essential for transferring electrons derived from the oxidation of glucose outside the peptidoglycan layer in the cell wall of E. faecalis biofilms formed on the surface of electrodes, in the absence of other potential electron mediators (e.g., yeast extract).

  16. Linezolid treatment of glycopeptide-resistant Enterococcus faecium in very low birth weight premature neonates.

    PubMed

    Hoehn, Rene; Groll, Andreas H; Schaefer, Volker; Bauer, Karl; Schloesser, Rolf L

    2006-03-01

    Glycopeptide-resistant Enterococcus faecium has emerged as an important nosocomial pathogen with limited therapeutic options. Here we report the successful treatment of glycopeptide-resistant E. faecium infection in two very low birth weight premature infants with the new oxazolidinone linezolid. Treatment with linezolid at a dosage of 10 mg/kg every 8 h intravenously for a duration of 16 days and 14 days, respectively, was well tolerated and led to complete clinical recovery and clearance of the organism from all body sites. The two cases support the clinical efficacy and safety of linezolid in very low birth weight premature neonates with glycopeptide-resistant E. faecium infections.

  17. Kinetic analysis of Enterococcus faecium L,D-transpeptidase inactivation by carbapenems.

    PubMed

    Dubée, Vincent; Arthur, Michel; Fief, Hélène; Triboulet, Sébastien; Mainardi, Jean-Luc; Gutmann, Laurent; Sollogoub, Matthieu; Rice, Louis B; Ethève-Quelquejeu, Mélanie; Hugonnet, Jean-Emmanuel

    2012-06-01

    Bypass of classical penicillin-binding proteins by the L,D-transpeptidase of Enterococcus faecium (Ldt(fm)) leads to high-level ampicillin resistance in E. faecium mutants, whereas carbapenems remain the lone highly active β-lactams. Kinetics of Ldt(fm) inactivation was determined for four commercial carbapenems and a derivative obtained by introducing a minimal ethyl group at position 2. We show that the bulky side chains of commercial carbapenems have both positive and negative effects in preventing hydrolysis of the acyl enzyme and impairing drug binding.

  18. Antimicrobial resistance in Enterococcus spp. strains isolated from organic chicken, conventional chicken, and turkey meat: a comparative survey.

    PubMed

    Miranda, J M; Guarddon, M; Mondragon, A; Vázquez, B I; Fente, C A; Cepeda, A; Franco, C M

    2007-04-01

    The mean counts of Enterococcus spp. were determined for 30 samples each of organic chicken meat, conventional chicken meat, and turkey meat, and differences for Enterococcus contamination in meat were determined. Two enterococci strains from each sample were isolated to obtain a total of 180 strains, and resistance to ampicillin, chloramphenicol, doxycycline, ciprofloxacin, erythromycin, gentamicin, nitrofurantoin, and vancomycin was determined by a disk diffusion method. Average counts obtained showed that Enterococcus mean counts from organic chicken meat (3.18 log CFU/g) were significantly higher than those obtained from conventional chicken meat (2.06 log CFU/g) or conventional turkey meat (1.23 log CFU/g). However, the resistance data obtained showed that isolates from organic chicken meat were less resistant than enterococci isolates from conventional chicken meat to ampicillin (P = 0.0067), chloramphenicol (P = 0.0154), doxycycline (P = 0.0277), ciprofloxacin (P = 0.0024), erythromycin (P = 0.0028), and vancomycin (P = 0.0241). In addition, isolates from organic chicken were less resistant than conventional turkey meat isolates to ciprofloxacin (P = 0.001) and erythromycin (P = 0.0137). Multidrug-resistant isolates were found in every group tested, but rates of multidrug-resistant strains were significantly higher in conventional chicken and turkey than those obtained from organic chicken meat. Enterococcus faecalis was the most common species isolated from organic chicken (36.67%), whereas Enterococcus durans was the most common species isolated from conventional chicken (58.33%) and turkey (56.67%). The rates obtained for antimicrobial resistance suggest that although organic chicken meat may have higher numbers of Enterococcus, these bacteria present a lower level of antimicrobial resistance.

  19. Commensal symbiosis between a Lactococcus lactis strain and an Enterococcus mundtii strain increases cell yield in constituted broth.

    PubMed

    Kimoto-Nira, H; Ohmori, H; Suzuki, C

    2012-11-01

    To exert their beneficial effects, probiotics need to survive in the stringent conditions of the gastrointestinal tract. Symbiosis between different bacteria is a potential way of enhancing this survival. In developing new probiotic cultures, we investigated the synergic effect between Enterococcus mundtii IFO 13712 and 7 strains of Lactococcus lactis, many of which are widely used as starter bacteria for making dairy products and have probiotic properties. The growth yield of a mixed culture of L. lactis strain Y and IFO 13712 in de Man, Rogosa, and Sharpe broth was greater than that of a single culture. Supernatant from culture of strain IFO 13712 enhanced the growth of strain Y, but that of strain Y did not enhance the growth of strain IFO 13712. This commensalism phenomenon was confirmed by using a simpler tryptone-yeast extract-glucose (TYG) broth. Increased cell yield in mixed culture of the 2 strains compared with single cultures was observed in TYG broth in the presence of both Tween 80 and citrate but not in TYG broth alone or TYG broth containing either Tween 80 or citrate. Thus, the Tween 80 and citrate in the broth contributed to the commensalism. Metabolite analysis revealed that ethanol production in the co-metabolism of glucose and citrate by strain Y was suppressed by mixed culture in TYG broth containing Tween 80 and citrate, compared with that in TYG broth containing citrate alone. The mechanism supporting the observed commensal symbiosis between strains Y and IFO 13712 was the increase in availability of glucose for lactate production by strain Y because, in glycolysis, the pathway from glucose to lactate is energic, whereas the pathway from glucose to ethanol is not. Whether growth stimulation of strain Y by mixing it with IFO 13712 in milk products will enhance the survival of strain Y in the intestine remains to be elucidated.

  20. Dietary Enterococcus faecalis LAB31 improves growth performance, reduces diarrhea, and increases fecal Lactobacillus number of weaned piglets.

    PubMed

    Hu, Yuanliang; Dun, Yaohao; Li, Shenao; Zhang, Dongxiao; Peng, Nan; Zhao, Shumiao; Liang, Yunxiang

    2015-01-01

    Lactic acid bacteria (LAB) have been shown to enhance performance of weaned piglets. However, few studies have reported the addition of LAB Enterococcus faecalis as alternatives to growth promoting antibiotics for weaned piglets. This study evaluated the effects of dietary E. faecalis LAB31 on the growth performance, diarrhea incidence, blood parameters, fecal bacterial and Lactobacillus communities in weaned piglets. A total of 360 piglets weaned at 26 ± 2 days of age were randomly allotted to 5 groups (20 pens, with 4 pens for each group) for a trial of 28 days: group N (negative control, without antibiotics or probiotics); group P (Neomycin sulfate, 100 mg/kg feed); groups L, M and H (supplemented with E. faecalis LAB31 0.5×109, 1.0×109, and 2.5×109 CFU/kg feed, respectively). Average daily gain and feed conversion efficiency were found to be higher in group H than in group N, and showed significant differences between group H and group P (P0 < 0.05). Furthermore, groups H and P had a lower diarrhea index than the other three groups (P0 < 0.05). Denaturing gradient gel electrophoresis (DGGE) showed that the application of probiotics to the diet changed the bacterial community, with a higher bacterial diversity in group M than in the other four groups. Real-time PCR revealed that the relative number of Lactobacillus increased by addition of probiotics, and was higher in group H than in group N (P0 < 0.05). However, group-specific PCR-DGGE showed no obvious difference among the five groups in Lactobacillus composition and diversity. Therefore, the dietary addition of E. faecalis LAB31 can improve growth performance, reduce diarrhea, and increase the relative number of Lactobacillus in feces of weaned piglets.

  1. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    PubMed

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    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.

  2. Dietary Enterococcus faecalis LAB31 Improves Growth Performance, Reduces Diarrhea, and Increases Fecal Lactobacillus Number of Weaned Piglets

    PubMed Central

    Hu, Yuanliang; Dun, Yaohao; Li, Shenao; Zhang, Dongxiao; Peng, Nan; Zhao, Shumiao; Liang, Yunxiang

    2015-01-01

    Lactic acid bacteria (LAB) have been shown to enhance performance of weaned piglets. However, few studies have reported the addition of LAB Enterococcus faecalis as alternatives to growth promoting antibiotics for weaned piglets. This study evaluated the effects of dietary E. faecalis LAB31 on the growth performance, diarrhea incidence, blood parameters, fecal bacterial and Lactobacillus communities in weaned piglets. A total of 360 piglets weaned at 26 ± 2 days of age were randomly allotted to 5 groups (20 pens, with 4 pens for each group) for a trial of 28 days: group N (negative control, without antibiotics or probiotics); group P (Neomycin sulfate, 100 mg/kg feed); groups L, M and H (supplemented with E. faecalis LAB31 0.5×109, 1.0×109, and 2.5×109 CFU/kg feed, respectively). Average daily gain and feed conversion efficiency were found to be higher in group H than in group N, and showed significant differences between group H and group P (P0 < 0.05). Furthermore, groups H and P had a lower diarrhea index than the other three groups (P0 < 0.05). Denaturing gradient gel electrophoresis (DGGE) showed that the application of probiotics to the diet changed the bacterial community, with a higher bacterial diversity in group M than in the other four groups. Real-time PCR revealed that the relative number of Lactobacillus increased by addition of probiotics, and was higher in group H than in group N (P0 < 0.05). However, group-specific PCR-DGGE showed no obvious difference among the five groups in Lactobacillus composition and diversity. Therefore, the dietary addition of E. faecalis LAB31 can improve growth performance, reduce diarrhea, and increase the relative number of Lactobacillus in feces of weaned piglets. PMID:25617897

  3. Intestinal microbiota and oral administration of Enterococcus faecium associated with the growth performance of new-born piglets.

    PubMed

    Wang, Y B; Du, W; Fu, A K; Zhang, X P; Huang, Y; Lee, K H; Yu, K; Li, W F; Li, Y L

    2016-09-01

    The oral administration of Enterococcus faecium EF1 to new-born suckling and weaning piglets along with their growth performances and intestinal microbiota was investigated in this study. Twenty-four new-born piglets were initially divided into 2 groups. The probiotics group received 2 ml of 10% sterilised skimmed milk by oral gavage supplemented with 6×10(8) cfu/ml viable E. faecium EF1 at the first, the third and the fifth day after birth, while the control group received 2 ml of 10% sterilised skimmed milk without probiotics at the same time. Results showed that oral administration of E. faecium EF1 was associated with a remarkable increase on the body weight of piglets for both suckling and weaning periods, by 30.73% (P<0.01) and 320.84% (P<0.01), and also decreased the diarrhoea rate, by 43.21% (P<0.05) and 71.42% (P<0.05), respectively. In addition, 454-pyrosequencing analysis revealed that there was no significant difference in the intestinal microbial diversity of the suckling piglets between the two groups; nevertheless, when compared to the control group, the relative abundance of Firmicutes in the probiotics group was substantially augmented, while the relative abundance of Proteobacteria, Bacteroidetes and Fusobacteria diminished. However, results indicated that oral administration of E. faecium EF1 did not have any influence on the relative abundance of Firmicutes in weaning piglets rather than increasing the relative abundance of Bacteroidetes and decreasing the relative abundance of Proteobacteria. Furthermore, at the level of the Firmicutes phylum, the relative abundance of Lactobacillales in the probiotic group increased significantly. These findings suggest that oral administration of E. faecium EF1 to new-born piglets could improve the growth performance and intestinal microbiota of piglets for both suckling and weaning periods.

  4. Unraveling Antimicrobial Resistance Genes and Phenotype Patterns among Enterococcus faecalis Isolated from Retail Chicken Products in Japan

    PubMed Central

    Hidano, Arata; Yamamoto, Takehisa; Hayama, Yoko; Muroga, Norihiko; Kobayashi, Sota; Nishida, Takeshi; Tsutsui, Toshiyuki

    2015-01-01

    Multidrug-resistant enterococci are considered crucial drivers for the dissemination of antimicrobial resistance determinants within and beyond a genus. These organisms may pass numerous resistance determinants to other harmful pathogens, whose multiple resistances would cause adverse consequences. Therefore, an understanding of the coexistence epidemiology of resistance genes is critical, but such information remains limited. In this study, our first objective was to determine the prevalence of principal resistance phenotypes and genes among Enterococcus faecalis isolated from retail chicken domestic products collected throughout Japan. Subsequent analysis of these data by using an additive Bayesian network (ABN) model revealed the co-appearance patterns of resistance genes and identified the associations between resistance genes and phenotypes. The common phenotypes observed among E. faecalis isolated from the domestic products were the resistances to oxytetracycline (58.4%), dihydrostreptomycin (50.4%), and erythromycin (37.2%), and the gene tet(L) was detected in 46.0% of the isolates. The ABN model identified statistically significant associations between tet(L) and erm(B), tet(L) and ant(6)-Ia, ant(6)-Ia and aph(3’)-IIIa, and aph(3’)-IIIa and erm(B), which indicated that a multiple-resistance profile of tetracycline, erythromycin, streptomycin, and kanamycin is systematic rather than random. Conversely, the presence of tet(O) was only negatively associated with that of erm(B) and tet(M), which suggested that in the presence of tet(O), the aforementioned multiple resistance is unlikely to be observed. Such heterogeneity in linkages among genes that confer the same phenotypic resistance highlights the importance of incorporating genetic information when investigating the risk factors for the spread of resistance. The epidemiological factors that underlie the persistence of systematic multiple-resistance patterns warrant further investigations with

  5. Enterococcus faecalis Produces Abundant Extracellular Structures Containing DNA in the Absence of Cell Lysis during Early Biofilm Formation

    PubMed Central

    Barnes, Aaron M. T.; Ballering, Katie S.; Leibman, Rachel S.; Wells, Carol L.; Dunny, Gary M.

    2012-01-01

    ABSTRACT Enterococcus faecalis is a common Gram-positive commensal bacterium of the metazoan gastrointestinal tract capable of biofilm formation and an opportunistic pathogen of increasing clinical concern. Dogma has held that biofilms are slow-growing structures, often taking days to form mature microcolonies. Here we report that extracellular DNA (eDNA) is an integral structural component of early E. faecalis biofilms (≤4 h postinoculation). Combining cationic dye-based biofilm matrix stabilization techniques with correlative immuno-scanning electron microscopy (SEM) and fluorescent techniques, we demonstrate that—in early E. faecalis biofilms—eDNA localizes to previously undescribed intercellular filamentous structures, as well as to thick mats of extruded extracellular matrix material. Both of these results are consistent with previous reports that early biofilms are exquisitely sensitive to exogenous DNase treatment. High-resolution SEM demonstrates a punctate labeling pattern in both structures, suggesting the presence of an additional, non-DNA constituent. Notably, the previously described fratricidal or lytic mechanism reported as the source of eDNA in older (≥24 h) E. faecalis biofilms does not appear to be at work under these conditions; extensive visual examination by SEM revealed a striking lack of lysed cells, and bulk biochemical assays also support an absence of significant lysis at these early time points. In addition, some cells demonstrated eDNA labeling localized at the septum, suggesting the possibility of DNA secretion from metabolically active cells. Overall, these data are consistent with a model in which a subpopulation of viable E. faecalis cells secrete or extrude DNA into the extracellular matrix. PMID:22829679

  6. Host-derived probiotics Enterococcus casseliflavus improves resistance against Streptococcus iniae infection in rainbow trout (Oncorhynchus mykiss) via immunomodulation.

    PubMed

    Safari, Reza; Adel, Milad; Lazado, Carlo C; Caipang, Christopher Marlowe A; Dadar, Maryam

    2016-05-01

    The present study evaluated the benefits of dietary administration of host-derived candidate probiotics Enterococcus casseliflavus in juvenile rainbow trout Oncorhynchus mykiss. Experimental diets were prepared by incorporating the microorganisms in the basal feed at 3 inclusion levels (i.e. 10(7) CFU g(-1) of feed [T1], 10(8) CFU g(-1) of feed [T2], 10(9) CFU g(-1) of feed [T3]). The probiotic feeds were administered for 8 weeks, with a group fed with the basal diet serving as control. The effects on growth performance, gut health, innate immunity and disease resistance were evaluated. Results showed that growth performance parameters were significantly improved in T2 and T3 groups. Activities of digestive enzymes such as trypsin and lipase were significantly higher in these two groups as well. Gut micro-ecology was influenced by probiotic feeding as shown by the significant increase in intestinal lactic acid bacteria and total viable aerobic counts in T2 and T3. Humoral immunity was impacted by dietary probiotics as total serum protein and albumin were significantly elevated in T3. The levels of serum IgM significantly increased in all probiotic fed groups at week 8; with the T3 group registering the highest increment. Respiratory burst activity of blood leukocytes were significantly improved in T2 and T3. Hematological profiling further revealed that neutrophil counts significantly increased in all probiotic fed groups. Challenge test showed that probiotic feeding significantly improved host resistance to Streptococcus iniae infection, specifically in T2 and T3 where a considerable modulation of immune responses was observed. Taken together, this study demonstrated E. casseliflavus as a potential probiotics for rainbow trout with the capability of improving growth performance and enhancing disease resistance by immunomodulation.

  7. A Comparison between Antibacterial Activity of Propolis and Aloe vera on Enterococcus faecalis (an In Vitro Study).

    PubMed

    Ehsani, Maryam; Amin Marashi, Mahmood; Zabihi, Ebrahim; Issazadeh, Maryam; Khafri, Soraya

    2013-01-01

    Removing the bacteria, including Enterococcus faecalis, from the root canal is one of the important aims in endodontic treatment.We aimed to compare the antibacterial activity of Chlorhexidine with two natural drugs. The antibacterial activities of three different propolis extracts (alcohol concentrations: 0, 15, 40%) and Aloe vera gel on E. faecalis were compared using three methods: disk diffusion, microdilution and direct contact test. In addition to the above bacterium, the Aloe vera gel effect on Staphylococcus aureus and Streptococcus mutans was evaluated. Disk diffusion test revealed that propolis ethanolic extracts (the alcohol concentration of 15 and 40%) and Aloe vera gel have antibacterial activities but aqueous extract of propolis did not show any effect in this test. The MICs for propolis ethanolic extracts, Aloe vera gel and aqueous extract of propolis (0% alcohol) were 313 µg/ml, 750 µg/ml, 2250 µg/ml, and ≥ 500 µg/ml respectively, much higher than the Chlorhexidine one. In direct contact test, contrary to Aloe vera, all three propolis extracts showed antibacterial effects on E. faecalis. The Aloe vera gel also showed significant antibacterial effect on S.aureus and S.mutans. The hydroalcoholic extracts of propolis and Aloe vera gel had antibacterial effects on E. faecalis, however, propolis is more potent than Aloe vera. The antibacterial effect of Aloe vera on S. aureus and S. mutans is low (MIC ≥ 2250 µg/ml). Appropriate concentrations of alcoholic extracts of propolis and some fractions of Aloe vera gel might be good choices for disinfecting the root canal in endodontic treatments.

  8. Enterococcus faecalis utilizes maltose by connecting two incompatible metabolic routes via a novel maltose 6'-phosphate phosphatase (MapP).

    PubMed

    Mokhtari, Abdelhamid; Blancato, Víctor S; Repizo, Guillermo D; Henry, Céline; Pikis, Andreas; Bourand, Alexa; de Fátima Álvarez, María; Immel, Stefan; Mechakra-Maza, Aicha; Hartke, Axel; Thompson, John; Magni, Christian; Deutscher, Josef

    2013-04-01

    Similar to Bacillus subtilis, Enterococcus faecalis transports and phosphorylates maltose via a phosphoenolpyruvate (PEP):maltose phosphotransferase system (PTS). The maltose-specific PTS permease is encoded by the malT gene. However, E. faecalis lacks a malA gene encoding a 6-phospho-α-glucosidase, which in B. subtilis hydrolyses maltose 6'-P into glucose and glucose 6-P. Instead, an operon encoding a maltose phosphorylase (MalP), a phosphoglucomutase and a mutarotase starts upstream from malT. MalP was suggested to split maltose 6-P into glucose 1-P and glucose 6-P. However, purified MalP phosphorolyses maltose but not maltose 6'-P. We discovered that the gene downstream from malT encodes a novel enzyme (MapP) that dephosphorylates maltose 6'-P formed by the PTS. The resulting intracellular maltose is cleaved by MalP into glucose and glucose 1-P. Slow uptake of maltose probably via a maltodextrin ABC transporter allows poor growth for the mapP but not the malP mutant. Synthesis of MapP in a B. subtilis mutant accumulating maltose 6'-P restored growth on maltose. MapP catalyses the dephosphorylation of intracellular maltose 6'-P, and the resulting maltose is converted by the B. subtilis maltose phosphorylase into glucose and glucose 1-P. MapP therefore connects PTS-mediated maltose uptake to maltose phosphorylase-catalysed metabolism. Dephosphorylation assays with a wide variety of phospho-substrates revealed that MapP preferably dephosphorylates disaccharides containing an O-α-glycosyl linkage.

  9. Cold-shock RNA-binding protein CspR is also exposed to the surface of Enterococcus faecalis.

    PubMed

    Michaux, Charlotte; Saavedra, Luis Felipe Romero; Reffuveille, Fany; Bernay, Benoît; Goux, Didier; Hartke, Axel; Verneuil, Nicolas; Giard, Jean-Christophe

    2013-10-01

    CspR has been characterized recently as a cold-shock RNA-binding protein in Enterococcus faecalis, a natural member of the gastro-intestinal tract capable of switching from a commensal relationship with the host to an important nosocomial pathogen. In addition to its involvement in the cold-shock response, CspR also plays a role in the long-term survival and virulence of E. faecalis. In the present study, we demonstrated that anti-CspR immune rabbit serum protected larvae of Galleria mellonella against a lethal challenge of the WT strain. These results suggested that CspR might have a surface location. This hypothesis was verified by Western blot that showed detection of CspR in the total as well as in the surface protein fraction. In addition, identification of surface polypeptides by proteolytic shaving of intact bacterial cells followed by liquid chromatography-MS-MS revealed that cold-shock proteins (EF1367, EF2939 and CspR) were present on the cell surface. Lastly, anti-CspR immune rabbit serum was used for immunolabelling and detected with colloidal gold-labelled goat anti-rabbit IgG in order to determine the immunolocalization of CspR on E. faecalis WT strain. Electron microscopy images confirmed that the cold-shock protein RNA-binding protein CspR was present in both cytoplasmic and surface parts of the cell. These data strongly suggest that CspR, in addition to being located intracellularly, is also present in the extracellular protein fraction of the cells and has important functions in the infection process of Galleria larvae.

  10. Determination of antimicrobial resistance of Enterococcus strains isolated from pigs and their genotypic characterization by method of amplification of DNA fragments surrounding rare restriction sites (the ADSRRS-fingerprinting).

    PubMed

    Nowakiewicz, Aneta; Ziółkowska, Grażyna; Trościańczyk, Aleksandra; Zięba, Przemysław; Gnat, Sebastian

    2016-11-28

    In this study, we analysed phenotypic resistance profiles and their reflection in the genomic profiles of Enterococcus spp. strains isolated from pigs raised on different farms. Samples were collected from five pig farms (n=90 animals) and tested for Enterococcus. Minimum inhibitory concentrations of 12 antimicrobials were determined using the broth microdilution method, and epidemiological molecular analysis of strains belonging to selected species (E. faecalis, E. faecium and E. hirae) was performed using the ADSRRS-fingerprinting method with a few modifications. The highest percentage of strains were resistant to tetracycline (73.4%), erythromycin and tylosin (42.5%), and rifampicin (25.2%) as well as a large number exhibited high-level resistance to both kanamycin (25.2%) and streptomycin (27.6%). The strains of E. faecalis, E. faecium and E. hirae (n=184) revealed varied phenotypic resistance profiles, among which as many as seven met the criteria for multi-drug resistance (30,4% of strains tested). ADSRRS-fingerprinting analysis produced 17 genotypic profiles of individual strains which were correlated with their phenotypic resistance profiles. Only E. hirae strains susceptible to all of the chemotherapeutics tested had two different ADSRRS profiles. Moreover, eight animals were carriers of more than one genotype belonging to the same Enterococcus spp., mainly E. faecalis. Given the possibility of transmission to humans of the high resistance/multi-drug resistance enterococci and the significant role of pigs as food animals in this process, it is necessary to introduce a multi-level control strategy by carrying out research on the resistance and molecular characteristics of indicator bacterial strains isolated from animals on individual farms.

  11. Enterococcus faecium isolated from honey synthesized bacteriocin-like substances active against different Listeria monocytogenes strains.

    PubMed

    Ibarguren, Carolina; Raya, Raúl R; Apella, María C; Audisio, M Carina

    2010-02-01

    Four Enterococcus faecium strains, isolated from honeycombs (C1 and M2d strains) and feral combs (Mori1 and M1b strains) secreted antimicrobial substances active against fourteen different Listeria spp. strains. The antimicrobial compound(s) present in the cell free supernatant were highly thermostable (121 degrees C for 15 min) and inactivated by proteolytic enzymes, but not by alpha-amylase and lipase, thus suggesting a peptidic nature. Since the structural bacteriocin gene determinants of enterocins A and B were PCR amplified from the four E. faecium isolates, only the bacteriocin produced by strain C1 was further characterized: it showed a broad band of approximately 4.0-7.0 kDa in SDS-PAGE and was bactericidal (4 log decrease) against L. monocytogenes 99/287. L. monocytogenes 99/287R, a clone spontaneously resistant to the enterocin produced by E. avium DSMZ17511 (ex PA1), was not inhibited by the enterocin-like compounds produced by strain C1. However, it was inhibited in mixed culture fermentations by E. faecium C1 and a bacteriostatic effect was observed. The bacteriocin-producer Enterococcus strains were not haemolytic; gelatinase negative and sensitive to vancomycin and other clinically relevant antibiotics.

  12. Antimicrobial resistance pattern and genetic correlation in Enterococcus faecium isolated from healthy volunteers.

    PubMed

    Asadian, M; Sadeghi, J; Rastegar Lari, A; Razavi, Sh; Hasannejad Bibalan, M; Talebi, M

    2016-03-01

    Enterococci are known as a cause of nosocomial infections and this aptitude is intensified by the growth of antibiotic resistance. In the present study, Enterococcus faecium isolates from healthy volunteers were considered to determine the antibiotic resistance profiles and genetic correlation. A total 91 normal flora isolates of enterococci were included in this study. Identification of Enterococcus genus and species were done by biochemical and PCR methods, respectively. Sensitivity for 10 antibiotics was determined and genetic relatedness of all isolates was assessed using Repetitive Element Palindromic PCR (REP-PCR) followed by Pulse Field Gel Electrophoresis (PFGE) on the representative patterns. None of the isolates were resistant to teicoplanin, vancomycin, quinupristin-dalfopristin, linezolid, chloramphenicol, ampicillin and high-level gentamicin. On the other hand, the resistance rate was detected in 30.7%, 23%, and 3.29% of isolates for erythromycin, tetracycline and ciprofloxacin, respectively. The results of PFGE showed 19 (61.5% of our isolates) common types (CT) and 35 (38.5%) single types (ST) amongst the isolates. This is the first study to describe antibiotic resistance pattern and genetic relationship among normal flora enterococci in Iran. This study showed no prevalence of Vancomycin Resistant Enterococci (VRE) and high degrees of diversity among normal flora isolates by genotyping using PFGE.

  13. Antimicrobial activity of essential oils and chloroform alone and combinated with cetrimide against Enterococcus faecalis biofilm

    PubMed Central

    Ferrer Luque, Carmen Maria; González-Rodríguez, Maria Paloma; Arias-Moliz, Maria Teresa; Baca, Pilar

    2013-01-01

    Abstract The Enterococcus faecalis bacteria have been identified as the most commonly recovered species from teeth with persistent endodontic infections. The antimicrobial activity of essential oils and chloroform (CHL), alone and in association with various concentrations of cetrimide (CTR), against biofilm of Enterococcus faecalis was investigated. Solutions of CHL, eucalyptus oil (EO) and orange oil (OO) associated with CTR at 0.3%, 0.2%, 0.1%, and 0.05% were used to determine antimicrobial activity by exposing treated bovine dentine blocks to E. faecalis. Biofilms grown in the dentine blocks for 7 days were exposed to solutions for 2 and 5 min. Biofilm reduction between OO and EO at 2 min did not show any significant differences; however, OO had a higher kill percentage of biofilms than did the eucalyptus oil at 5 min (p < 0.01). Combinations with CTR at all concentrations achieved a 100% kill rate at 2 and 5 min. The association of CTR with solvent agents achieved the maximum antimicrobial activity against E. faecalis biofilms in dentine. PMID:24265917

  14. The effects of submerged aquatic vegetation on the persistence of environmental populations of Enterococcus spp.

    PubMed

    Badgley, Brian D; Thomas, Florence I M; Harwood, Valerie J

    2010-05-01

    Enterococcus spp. are utilized worldwide as faecal indicator bacteria, but certain strains exhibit extended survival in environmental habitats and the factors influencing their persistence are poorly understood. We used flowing freshwater mesocosms to explore the effect of submerged aquatic vegetation (SAV) on the persistence of natural enterococci populations from a subtropical lake. The highest mean densities of culturable enterococci over 2 weeks occurred in SAV [8.6 x 10(2) colony-forming units (cfu) per 100 g wet weight], followed by sediments (1.3 x 10(2) cfu per 100 g) and water (18 cfu per 100 ml). However, due to relative differences in the total mass of each substrate in the entire system (water > sediments > SAV), SAV-associated enterococci represented only a minor proportion of the total population. Vegetated mesocosms harboured significantly higher mean cfu per mesocosm and cfu densities in sediments compared with their unvegetated counterparts, suggesting that SAV indirectly facilitates persistence in aquatic habitats. Populations were dominated (> 96%) by a single Enterococcus casseliflavus strain according to BOX-PCR genotyping, which did not change over the 10-month study and strongly suggests bacterial replication in the lake. The presence of such strains in the environment may represent highly competitive, naturalized and reproducing indicator bacteria populations that are not directly related to pollution events.

  15. Antibacterial Effect of All-in-one Self-etch Adhesives on Enterococcus faecalis

    PubMed Central

    Ebrahimi Chaharom, Mohammad Esmaeel; Ajami, Amir Ahmad; Abed Kahnamouei, Mehdi; Jafari Navimipour, Elmira; Tehranchi, Pardis; Zand, Vahid; Sadeghi, Mohammad Reza; Sohrabi, Aydin

    2014-01-01

    Background and aims. The aim of this study was to evaluate the antibacterial activity of one-step self-etch adhesives on Enterococcus faecalis on days 1, 7 and 14 with the use of modified direct contact test. Materials and methods. The modified directcontact test was used to evaluate the antibacterial effect of Adper Easy One, Bond Force, Clearfil S3 Bond, Futurabond M, G-Bond, iBond and OptiBond All-in-one adhesives on Enterococcus faecalis after aging the samples in phosphate-buffered saline for one, seven and fourteen days. Data were analyzed using one-way ANOVA and post hoc Tukey tests. Aging effect of each adhesive was evaluated by paired-sample test. In this study, P<0.05 was considered significant. Results. All the tested adhesives exhibited antibacterial activity after one day and had significant differences with the positive control group (P<0.05). After one week, OptiBond All-in-one, iBond and Futurabond M exhibited significant differences in bacterial growth from other groups (P<0.05). There were no significant differences between the groups in two weeks (P>0.05). Conclusion. iBond exhibited the highest antibacterial effect on E. faecalis after one week. Futurabond and OptiBond All-in-one exhibited antibacterial effects against E. faecalis for one week. PMID:25587384

  16. Echinoderms from Azores islands: an unexpected source of antibiotic resistant Enterococcus spp. and Escherichia coli isolates.

    PubMed

    Marinho, Catarina; Silva, Nuno; Pombo, Sofia; Santos, Tiago; Monteiro, Ricardo; Gonçalves, Alexandre; Micael, Joana; Rodrigues, Pedro; Costa, Ana Cristina; Igrejas, Gilberto; Poeta, Patrícia

    2013-04-15

    The prevalence of antibiotic resistance and the implicated mechanisms of resistance were evaluated in Enterococcus spp. and Escherichia coli, isolated from a total of 250 faecal samples of echinoderms collected from Azorean waters (Portugal). A total of 144 enterococci (120 Enterococcus faecium, 14 E. hirae, 8 E. faecalis, 2 E. gallinarum) and 10 E. coli were recovered. High percentages of resistance in enterococci were found for erythromycin, ampicillin, tetracyclin and ciprofloxacin. The erm(A) or erm(B), tet(M) and/or tet(L), vat(D), aac(6')-aph(2″) and aph(3')-IIIa genes were found in isolates resistant to erythromycin, tetracycline, quinupristin/dalfopristin, high-level gentamicin and high-level kanamycin, respectively. Resistance in E. coli isolates was detected for streptomycin, amikacin, tetracycline and tobramycin. The aadA gene was found in streptomycin-resistant isolates and tet(A)+tet(B) genes in tetracycline-resistant isolates. The data recovered are essential to improve knowledge about the dissemination of resistant strains through marine ecosystems and the possible implications involved in transferring these resistances either to other animals or to humans.

  17. Are Enterococcus populations present during malolactic fermentation of red wine safe?

    PubMed

    Pérez-Martín, Fátima; Seseña, Susana; Izquierdo, Pedro Miguel; Palop, María Llanos

    2014-09-01

    The aim of this study was the genetic characterisation and safety evaluation of 129 Enterococcus isolates obtained from wine undergoing malolactic fermentation. Genetic characterisation by randomly amplified polymorphic DNA-PCR displayed 23 genotypes. 25 isolates representative of all genotypes were identified as Enterococcus faecium by species-specific PCR and assayed for antibiotic resistance, presence of virulence genes and aminobiogenic capacity, both in decarboxylase medium and wine. The aminobiogenic capacity in wine was analysed in presence (assay 1) and absence (assay 2) of Oenococcus oeni CECT 7621. Resistance to tetracycline, cotrimoxazol, vancomycin and teicoplanin was exhibited by 96% of the strains, but none of them harboured the assayed virulence genes. All of the strains harboured the tyrosine decarboxylase (tdc) gene, while 44% were positive for tyramine in decarboxylase medium. Only five out of 25 strains survived in wine after seven days of incubation, and when concentrations of biogenic amines in wines were determined by HPLC, only those wines in which the five surviving strains occurred contained biogenic amines. Histamine, putrescine and cadaverine were detected in wines from both assays, although concentrations were higher in assay 2. Tyramine and phenylethylamine were detected only in absence of O. oeni. This research contributes for the knowledge of safety aspects of enterococci related to winemaking.

  18. Antimicrobial resistance and virulence traits in Enterococcus strains isolated from dogs and cats.

    PubMed

    Iseppi, Ramona; Messi, Patrizia; Anacarso, Imacolata; Bondi, Moreno; Sabia, Carla; Condò, Carla; de Niederhausern, Simona

    2015-07-01

    We investigated presence and prevalence of antibiotic-resistances and other biological characters in enterococci isolated from faeces of healthy dogs and cats because these microorganisms represent important human and veterinary pathogens/opportunists, and a significant burden for healthcare systems. In all samples (n=115) we detected enterococci, with a predominance of Enterococcus faecium (42; 36.5%) and Enterococcus faecalis (36; 31.3%) species, endowed with virulence traits and multidrug-resistance. The two predominant resistance patterns (erythromycin, tetracycline) were examined by polymerase chain reaction for tet and erm genes. Only tetM for tetracycline, and ermA and ermB for erythromycin were detected. PCR for gelatinase gene (gelE) was positive in 62.6% of isolates, but only 26.1% produce gelatinase suggesting the existence of silent genes. efaAfs and efaAfm genes were found in E. faecalis and E. faecium respectively. 89.6% of isolates produced bacteriocin-like substances with a prevailing action against Listeria genus and, among these, 33.9% were positive for the bacteriocin structural genes entA, entL50 or entP. According to our study, pet animals can be considered a reservoir of potentially pathogenic enterococci and we cannot exclude that those microorganisms may be responsible for opportunistic infections in high-risk pet owners.

  19. Enterococcus in surface waters from the Des Moines River (Iowa) watershed: location, persistence and vancomycin resistance.

    PubMed

    Larsen, Bryan; Essmann, Michael K; Geletta, Simon; Duff, Barbara

    2012-01-01

    The object of this study was to quantify vancomycin-resistant enterococci in surface water from Central Iowa obtained from April 2007 to August 2007. Water from established sampling sites in four watersheds was plated on bile-esculin agar. Presumptively identified enterococci were categorized as "above the level of concern" if the sample contained ≥ 107 CFU per 100 ml. Confirmation of isolates as enterococci was based on growth at elevated temperature in high salt and on Enterococcus agar. Isolates that grew on 6 μg/ml vancomycin agar were deemed resistant. PCR analysis of resistant strains characterized vancomycin resistance genes. 77.2% of surface water samples from Central Iowa contained enterococci. Among enterococcal isolates, 10.4% grew on media containing 6 μg/ml vancomycin. PCR analysis of resistance genes showed a preponderance of VanC2/C3 in the area studied and VanB was not detected. Vancomycin-resistant Enterococcus is present in Central Iowa surface waters but resistance rarely involved VanA genotypes. Nevertheless, the potential for community-acquired infections remains a risk.

  20. Identification of Polyketide Inhibitors Targeting 3-Dehydroquinate Dehydratase in the Shikimate Pathway of Enterococcus faecalis

    PubMed Central

    Hernandez-Valladares, Maria; Go, Maybelle Kho; Tung, Alvin; Aguda, Adeleke H.; Robinson, Robert C.; Yew, Wen Shan

    2014-01-01

    Due to the emergence of resistance toward current antibiotics, there is a pressing need to develop the next generation of antibiotics as therapeutics against infectious and opportunistic diseases of microbial origins. The shikimate pathway is exclusive to microbes, plants and fungi, and hence is an attractive and logical target for development of antimicrobial therapeutics. The Gram-positive commensal microbe, Enterococcus faecalis, is a major human pathogen associated with nosocomial infections and resistance to vancomycin, the “drug of last resort”. Here, we report the identification of several polyketide-based inhibitors against the E. faecalis shikimate pathway enzyme, 3-dehydroquinate dehydratase (DHQase). In particular, marein, a flavonoid polyketide, both inhibited DHQase and retarded the growth of Enterococcus faecalis. The purification, crystallization and structural resolution of recombinant DHQase from E. faecalis (at 2.2 Å resolution) are also reported. This study provides a route in the development of polyketide-based antimicrobial inhibitors targeting the shikimate pathway of the human pathogen E. faecalis. PMID:25072253

  1. Sensitivity of antibiotic resistant and antibiotic susceptible Escherichia coli, Enterococcus and Staphylococcus strains against ozone.

    PubMed

    Heß, Stefanie; Gallert, Claudia

    2015-12-01

    Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role.

  2. DNA Persistence and Relapses Questions on the Treatment Strategies of Enterococcus Infections of Prosthetic Valves

    PubMed Central

    Casalta, Jean-Paul; Thuny, Franck; Fournier, Pierre-Edouard; Lepidi, Hubert; Habib, Gilbert; Grisoli, Dominique; Raoult, Didier

    2012-01-01

    We used amplification of the 16S rRNA gene followed by sequencing to evaluate the persistence of bacterial DNA in explanted heart valve tissue as part of the routine work of a clinical microbiology laboratory, and we analyzed the role of this persistence in the relapses observed in our center. We enrolled 286 patients treated for infective endocarditis (IE) who had valve replacement surgery and were diagnosed according to the modified Duke’s criteria described by Li et al. from a total of 579 IE cases treated in our center. The patients were grouped based on the infecting bacteria, and we considered the 4 most common bacterial genus associated with IE separately (144 were caused by Streptococcus spp., 52 by Enterococcus spp., 58 by Staphylococcus aureus and 32 by coagulase-negative Staphylococcus). Based on our cohort, the risk of relapse in patients with enterococcal prosthetic valve infections treated with antibiotics alone was 11%. Bacterial DNA is cleared over time, but this might be a very slow process, especially with Enterococcus spp. Based on a comprehensive review of the literature performed on Medline, most reports still advise combined treatment with penicillin and an aminoglycoside for as long as 4–6 weeks, but there has been no consensus for the treatment of enterococcal infection of prostheses in IE patients. PMID:23300913

  3. Comparison of Enterococcus qPCR analysis results from fresh and marine waters on two real-tme instruments

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) will be recommending a quantitativ e polymerase chain reaction (qPCR) method targeting Enterococcus spp. as an option for monitoring recreational beach water quality. A practical consideration for widespread implementation of this o...

  4. Role of tyramine synthesis by food-borne Enterococcus durans in adaptation to the gastrointestinal tract environment.

    PubMed

    Fernández de Palencia, Pilar; Fernández, Maria; Mohedano, Maria Luz; Ladero, Victor; Quevedo, Cristina; Alvarez, Miguel A; López, Paloma

    2011-01-01

    Biogenic amines in food constitute a human health risk. Here we report that tyramine-producing Enterococcus durans strain IPLA655 (from cheese) was able to produce tyramine under conditions simulating transit through the gastrointestinal tract. Activation of the tyramine biosynthetic pathway contributed to binding and immunomodulation of enterocytes.

  5. Draft Genome Sequence of Enterococcus faecium Strain 58m, Isolated from Intestinal Tract Content of a Woolly Mammoth, Mammuthus primigenius.

    PubMed

    Goncharov, Artemiy; Grigorjev, Semyon; Karaseva, Alena; Kolodzhieva, Viktoria; Azarov, Daniil; Akhremenko, Yana; Tarasova, Lidia; Tikhonov, Alexei; Masharskiy, Alexey; Zueva, Lyudmila; Suvorov, Alexander

    2016-02-11

    Enterococcus faecium 58m is a putative ancient nonpathogenic strain isolated from the intestinal content of an adult woolly mammoth (Mammuthus primigenius). Here, we report its draft genome sequence, consisting of 60 contigs. In silico genomic analysis was performed to determine the genetic features and pathogenic potential of this microorganism.

  6. Identification of a novel genomic island specific to hospital-acquired clonal complex 17 Enterococcus faecium isolates.

    PubMed

    Heikens, Esther; van Schaik, Willem; Leavis, Helen L; Bonten, Marc J M; Willems, Rob J L

    2008-11-01

    Hospital-acquired clonal complex 17 (CC17) Enterococcus faecium strains are genetically distinct from indigenous strains and are enriched with resistance genes and virulence genes. We identified a genomic island in CC17 E. faecium tentatively encoding a metabolic pathway involved in carbohydrate transport and metabolism, which may provide a competitive advantage over the indigenous E. faecium microbiota.

  7. Draft Genome Sequence of Enterococcus faecium Strain 58m, Isolated from Intestinal Tract Content of a Woolly Mammoth, Mammuthus primigenius

    PubMed Central

    Goncharov, Artemiy; Grigorjev, Semyon; Kolodzhieva, Viktoria; Azarov, Daniil; Akhremenko, Yana; Tarasova, Lidia; Tikhonov, Alexei; Masharskiy, Alexey; Zueva, Lyudmila; Suvorov, Alexander

    2016-01-01

    Enterococcus faecium 58m is a putative ancient nonpathogenic strain isolated from the intestinal content of an adult woolly mammoth (Mammuthus primigenius). Here, we report its draft genome sequence, consisting of 60 contigs. In silico genomic analysis was performed to determine the genetic features and pathogenic potential of this microorganism. PMID:26868396

  8. Comparison of Enterococcus qPCR analysis results from fresh and marine water samples on two real-time instruments -

    EPA Science Inventory

    EPA is currently considering a quantitative polymerase chain reaction (qPCR) method, targeting Enterococcus spp., for beach monitoring. Improvements in the method’s cost-effectiveness may be realized by the use of newer instrumentation such as the Applied Biosystems StepOneTM a...

  9. Draft Genome Sequence of the Bacteriocinogenic Strain Enterococcus faecalis DBH18, Isolated from Mallard Ducks (Anas platyrhynchos)

    PubMed Central

    Arbulu, Sara; Jimenez, Juan J.; Borrero, Juan; Sánchez, Jorge; Frantzen, Cyril; Herranz, Carmen; Nes, Ingolf F.; Cintas, Luis M.; Diep, Dzung B.

    2016-01-01

    Here, we report the draft genome sequence of Enterococcus faecalis DBH18, a bacteriocinogenic lactic acid bacterium (LAB) isolated from mallard ducks (Anas platyrhynchos). The assembly contains 2,836,724 bp, with a G+C content of 37.6%. The genome is predicted to contain 2,654 coding DNA sequences (CDSs) and 50 RNAs. PMID:27417838

  10. Depth-dependent inactivation of Escherichia coli and Enterococcus faecalis in soil after manure application and simulated rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E.coli and Enterococcus serve as important water quality indicator organisms. Rainfall action on manured fields and pastures releases these organisms into soil with infiltrating water. They can then be released back to runoff during subsequent rainfall or irrigation events as soil solution interacts...

  11. Use of Enterococcus, BST and sterols as indicators for poultry pollution source tracking in surface and groundwater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study has applied Enterococcus, Bacterial Source Tracking (BST) and sterol analysis for pollution source identification from poultry sources. Fecal contamination was detected in 100% of surface water and 15% of groundwater sites tested. E. faecium was the dominant species in aged litter sampl...

  12. Prevalence and antibiotic resistance of Enterococcus spp. isolated from retail cheese, ready-to-eat salads, ham, and raw meat.

    PubMed

    Pesavento, G; Calonico, C; Ducci, B; Magnanini, A; Lo Nostro, A

    2014-08-01

    Food specimens were analyzed in order to research Enterococcus spp.: 636 samples of raw meat (227 beef, 238 poultry, and 171 pork), 278 samples of cheese (110 fresh soft cheese and 168 mozzarella cheese), 214 samples of ready-to-eat salads, and 187 samples of ham. 312 strains of Enterococcus spp samples were isolated, then identified and submitted to susceptibility tests against 11 antimicrobial agents. The predominant species were Enterococcus faecalis in raw meat and Enterococcus faecium in retail products. Low percentages of microorganisms were resistant to vancomycin (3.53%), teicoplanin (2.24%), linezolid (0.32%), and amoxicillin in combination with clavulanic acid (0.32%). A high percentage of resistance was noted in E. faecalis at high level gentamicin (21.9%) and tetracycline (60.6%). In general, strains of E. faecalis were more resistant than E. faecium. Enterococci should be considered not only potential pathogens, but also a reservoir of genes encoding antibiotic resistance which can be transferred to other microorganisms. Continuous monitoring of their incidence and emerging resistance is important in order to identify foods which potentially represent a real risk to the population, and to ensure effective treatment of human enterococcal infections.

  13. Identification, antimicrobial susceptibility, and virulence factors of Enterococcus spp. strains isolated from Camels in Canary Islands, Spain.

    PubMed

    Tejedor Junco, María Teresa; Gonzalez-Martin, Margarita; Rodriguez Gonzalez, Noe Francisco; Gutierrez, Carlos

    2015-01-01

    This study investigated the presence of Enterococcus spp. strains in camel faeces, their virulence factors, and resistance to the antibiotics commonly used as therapy of enterococcal infections. One hundred and seventy three Enterococcus strains were isolated and identified to species level using polymerase chain reaction (PCR). Susceptibility to 11 antimicrobials was determined by disk diffusion method. Minimal Inhibitory Concentrations (MIC) of penicillin, ampicillin, vancomycin, teicoplanin, gentamicin, and streptomycin were all determined. Genes encoding resistance to vancomycin, tetracycline, and erythromycin as well as genes encoding some virulence factors were identified by PCR. Enterococcus hirae (54.3%) and Enterococcus faecium (25.4%) were the species most frequently isolated. None of the strains were resistant to vancomycin, teicoplanin, ampicillin or showed high level aminoglycoside resistance (HLAR). Strains resistant to rifampicin (42.42%) were those most commonly found followed those resistant to trimethoprim - sulfamethoxazole (33.33%). The genes tetM, tetL, vanC1, and vanC2-C3 were detected in some strains. Virulence genes were not detected. Monitoring the presence of resistant strains of faecal enterococci in animal used with recreational purposes is important to prevent transmission of those strains to humans and to detect resistance or virulence genes that could be transferred to other clinically important bacteria.

  14. Investigation of mechanisms and molecular epidemiology of linezolid nonsusceptible Enterococcus faecalis isolated from a teaching hospital in China.

    PubMed

    Li, Bin; Ma, Chuan-Ling; Yu, Xiao; Sun, Yao; Li, Mei-Mei; Ye, Jian-Zhong; Zhang, Ya-Pei; Wu, Qing; Zhou, Tie-Li

    2016-08-01

    The epidemiological and molecular characteristics of eight linezolid nonsusceptible Enterococcus faecalis isolated from a teaching hospital in China (January to July 2014) were investigated. The target site modifications and cfr gene associated with linezolid resistance were not found. Results of the epidemiological investigation indicated that linezolid resistance possibly occurred on several independent occasions and was often not related to linezolid administration.

  15. Antibiotic and disinfectant susceptibility profiles of vancomycin-resistant Enterococcus faecium (VRE) isolated from community wastewater in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vancomycin-resistant Enterococcus faecium (VRE) previously isolated from human wastewater effluents in a nonclinical semiclosed agri-food system in Texas were characterized for susceptibility to antibiotics and disinfectants. The 50 VRE were resistant to eight fluoroquinolones and to 10 of 17 Natio...

  16. COMPARISON OF ENTEROCOCCUS MEASUREMENTS IN FRESHWATER AT TWO RECREATIONAL BEACHES BY QUANTITATIVE POLYMERASE CHAIN REACTION AND MEMBRANE FILER CULTURE ANALYSIS

    EPA Science Inventory

    Cell densities of the fecal pollution indicator genus, Enterococcus, were determined by a rapid (2-3 hr) quantitative PCR (QPCR) analysis based method in 100 ml water samples collected from recreational beaches on Lake Michigan and Lake Erie during the summer of 2003. Enumeration...

  17. Relation between Enterococcus concentrations and turbidity in fresh and saline recreational waters, coastal Horry County, South Carolina, 2003–04

    USGS Publications Warehouse

    Landmeyer, James E.; Garigen, Thomas J.

    2016-06-24

    The positive relation observed between turbidity and Enterococcus concentrations in surface water at the water-quality data collection station located in the channel that drains a freshwater swamp may be attributed to bacterial survival in the abundant channel bed sediments that characterized this more naturalized area. Surface-water bed sediments collected near each water-quality data collection station and the surf zone were incubated in static microcosms in the laboratory and analyzed for Enterococcus concentrations over time. Enterococcus concentrations continued to persist in bed sediments collected in the channel that drains the swamp even after almost 4 months of incubation. Conversely, enterococci were not observed to persist in bed sediments characterized by high specific conductance. Although it is currently (2016) unknown whether this persistence of enterococci demonstrates growth or viability, the data indicate that enterococci can exist in channel bed-sediment environments outside of a host for a long time. This observation confirms previous reports that challenge the use of Enterococcus concentrations as an indicator of the recent introduction of fecal-related material and the associated acute risk to other pathogens.

  18. Complete Genome Sequences of Isolates of Enterococcus faecium Sequence Type 117, a Globally Disseminated Multidrug-Resistant Clone

    PubMed Central

    Tedim, Ana P.; Lanza, Val F.; Manrique, Marina; Pareja, Eduardo; Ruiz-Garbajosa, Patricia; Cantón, Rafael; Baquero, Fernando; Tobes, Raquel

    2017-01-01

    ABSTRACT The emergence of nosocomial infections by multidrug-resistant sequence type 117 (ST117) Enterococcus faecium has been reported in several European countries. ST117 has been detected in Spanish hospitals as one of the main causes of bloodstream infections. We analyzed genome variations of ST117 strains isolated in Madrid and describe the first ST117 closed genome sequences. PMID:28360174

  19. Effect of vancomycin, tylosin, and chlortetracycline on vancomycin-resistant Enterococcus faecium colonization of broiler chickens during grow-out

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broiler chickens may serve as reservoirs for human colonization by vancomycin-resistant Enterococcus (VRE). We examined the effects of vancomycin and two commonly-used antimicrobial feed additives on VRE colonization in broiler chickens during grow-out. Chicks received unsupplemented feed or feed ...

  20. Revealing Rembrandt

    PubMed Central

    Parker, Andrew J.

    2014-01-01

    The power and significance of artwork in shaping human cognition is self-evident. The starting point for our empirical investigations is the view that the task of neuroscience is to integrate itself with other forms of knowledge, rather than to seek to supplant them. In our recent work, we examined a particular aspect of the appreciation of artwork using present-day functional magnetic resonance imaging (fMRI). Our results emphasized the continuity between viewing artwork and other human cognitive activities. We also showed that appreciation of a particular aspect of artwork, namely authenticity, depends upon the co-ordinated activity between the brain regions involved in multiple decision making and those responsible for processing visual information. The findings about brain function probably have no specific consequences for understanding how people respond to the art of Rembrandt in comparison with their response to other artworks. However, the use of images of Rembrandt's portraits, his most intimate and personal works, clearly had a significant impact upon our viewers, even though they have been spatially confined to the interior of an MRI scanner at the time of viewing. Neuroscientific studies of humans viewing artwork have the capacity to reveal the diversity of human cognitive responses that may be induced by external advice or context as people view artwork in a variety of frameworks and settings. PMID:24795552

  1. Virulence Genes among Enterococcus faecalis and Enterococcus faecium Isolated from Coastal Beaches and Human and Nonhuman Sources in Southern California and Puerto Rico

    PubMed Central

    Talavera, Ginamary Negrón; Hernández, Luis A. Ríos; Ambrose, Richard F.; Jay, Jennifer A.

    2016-01-01

    Most Enterococcus faecalis and E. faecium are harmless to humans; however, strains harboring virulence genes, including esp, gelE, cylA, asa1, and hyl, have been associated with human infections. E. faecalis and E. faecium are present in beach waters worldwide, yet little is known about their virulence potential. Here, multiplex PCR was used to compare the distribution of virulence genes among E. faecalis and E. faecium isolated from beaches in Southern California and Puerto Rico to isolates from potential sources including humans, animals, birds, and plants. All five virulence genes were found in E. faecalis and E. faecium from beach water, mostly among E. faecalis. gelE was the most common among isolates from all source types. There was a lower incidence of asa1, esp, cylA, and hyl genes among isolates from beach water, sewage, septage, urban runoff, sea wrack, and eelgrass as compared to human isolates, indicating that virulent strains of E. faecalis and E. faecium may not be widely disseminated at beaches. A higher frequency of asa1 and esp among E. faecalis from dogs and of asa1 among birds (mostly seagull) suggests that further studies on the distribution and virulence potential of strains carrying these genes may be warranted. PMID:27144029

  2. Evaluation of Enterococcus faecalis adhesion, penetration, and method to prevent the penetration of Enterococcus faecalis into root cementum: Confocal laser scanning microscope and scanning electron microscope analysis

    PubMed Central

    Halkai, Rahul S.; Hegde, Mithra N.; Halkai, Kiran R.

    2016-01-01

    Aim: To ascertain the role of Enterococcus faecalis in persistent infection and a possible method to prevent the penetration of E. faecalis into root cementum. Methodology: One hundred and twenty human single-rooted extracted teeth divided into five groups. Group I (control): intact teeth, Group II: no apical treatment done, Group III divided into two subgroups. In Groups IIIa and IIIb, root apex treated with lactic acid of acidic and neutral pH, respectively. Group IV: apical root cementum exposed to lactic acid and roughened to mimic the apical resorption. Group V: apical treatment done same as Group IV and root-end filling done using mineral trioxide aggregate (MTA). Apical one-third of all samples immersed in E. faecalis broth for 8 weeks followed by bone morphogenetic protein and obturation and again immersed into broth for 8 weeks. Teeth split into two halves and observed under confocal laser scanning microscope and scanning electron microscope, organism identified by culture and polymerase chain reaction techniques. Results: Adhesion and penetration was observed in Group IIIa and Group IV. Only adhesion in Group II and IIIB and no adhesion and penetration in Group I and V. Conclusion: Adhesion and penetration of E. faecalis into root cementum providing a long-term nidus for subsequent infection are the possible reason for persistent infection and root-end filling with MTA prevents the adhesion and penetration. PMID:27994316

  3. Antibacterial activity of Enterococcus faecium derived from Koopeh cheese against Listeria monocytogenes in probiotic ultra-filtrated cheese

    PubMed Central

    Hassanzadazar, Hassan; Ehsani, Ali; Mardani, Karim

    2014-01-01

    Viability of probiotic bacteria in food during maintenance and time of consuming in food has become a challenge in food hygiene and technology and is important for representing their beneficial health effects. The aim of this study was to determine the survival of probiotic Enterococcus faecium derived from Koopeh cheese added to industrial Iranian ultra-filtrated (UF) cheese and screening for antimicrobial activity of Enterococcus faecium against Listeria monocytogenes during two months of cheese ripening. Physiochemical and standard microbial methods were used for isolation of Enterococcus strains in cheese samples. The initial number of lactic acid bacteria (LAB) as starter culture was 6 Log g-1 in control samples. The counts started to decrease slightly after day seven (p < 0.05) and dropped to 5 Log g-1 at the end of 60 days. The count of LAB in the test groups decreased to 11 Log g-1 on the day 60 of ripening. The number of Enterococcus faecium was 6 Log g-1 on the day 60. The count of Listeria monocytogenes after 60 days of ripening in blank sample decreased 1 Log but in test samples with protective strain decreased 3 Log in 30 days and reached to zero at 45 days. There were not significant (p < 0.05) changes in chemical parameters such as fat, protein and total solid of UF cheese treatment groups. The results showed that Enterococcus faecium of Koopeh cheese was suitable for development of an acceptable probiotic UF cheese and could be adapted to industrial production of UF cheese. PMID:25568714

  4. First evidence of a membrane-bound, tyramine and beta-phenylethylamine producing, tyrosine decarboxylase in Enterococcus faecalis: a two-dimensional electrophoresis proteomic study.

    PubMed

    Pessione, Enrica; Pessione, Alessandro; Lamberti, Cristina; Coïsson, Daniel Jean; Riedel, Kathrin; Mazzoli, Roberto; Bonetta, Silvia; Eberl, Leo; Giunta, Carlo

    2009-05-01

    The soluble and membrane proteome of a tyramine producing Enterococcus faecalis, isolated from an Italian goat cheese, was investigated. A detailed analysis revealed that this strain also produces small amounts of beta-phenylethylamine. Kinetics of tyramine and beta-phenylethylamine accumulation, evaluated in tyrosine plus phenylalanine-enriched cultures (stimulated condition), suggest that the same enzyme, the tyrosine decarboxylase (TDC), catalyzes both tyrosine and phenylalanine decarboxylation: tyrosine was recognized as the first substrate and completely converted into tyramine (100% yield) while phenylalanine was decarboxylated to beta-phenylethylamine (10% yield) only when tyrosine was completely depleted. The presence of an aspecific aromatic amino acid decarboxylase is a common feature in eukaryotes, but in bacteria only indirect evidences of a phenylalanine decarboxylating TDC have been presented so far. Comparative proteomic investigations, performed by 2-DE and MALDI-TOF/TOF MS, on bacteria grown in conditions stimulating tyramine and beta-phenylethylamine biosynthesis and in control conditions revealed 49 differentially expressed proteins. Except for aromatic amino acid biosynthetic enzymes, no significant down-regulation of the central metabolic pathways was observed in stimulated conditions, suggesting that tyrosine decarboxylation does not compete with the other energy-supplying routes. The most interesting finding is a membrane-bound TDC highly over-expressed during amine production. This is the first evidence of a true membrane-bound TDC, longly suspected in bacteria on the basis of the gene sequence.

  5. An AraC-Type Transcriptional Regulator Encoded on the Enterococcus faecalis Pathogenicity Island Contributes to Pathogenesis and Intracellular Macrophage Survival▿

    PubMed Central

    Coburn, Phillip S.; Baghdayan, Arto S.; Dolan, GT; Shankar, Nathan

    2008-01-01

    A gene encoding a putative AraC-type transcriptional regulator was identified on the 153-kb pathogenicity island (PAI) found among virulent Enterococcus faecalis strains. In an effort to understand the function of this regulator, designated PerA (for pathogenicity island-encoded regulator), we first examined the expression of the perA gene in the original PAI strain MMH594 and in an unrelated clinical isolate E99 by reverse transcription-PCR. Interestingly, expression analysis revealed no detectable perA transcript in MMH594, whereas a transcript was observed in strain E99. Nucleotide sequence analysis revealed that this altered expression between the two strains was attributable to the differential location of an IS1191 element within the putative promoter region upstream of the perA gene. In order to determine the role of this putative regulator in E. faecalis pathogenesis, a perA-deficient mutant was created in strain E99, and the wild-type and mutant pair were compared for phenotypic differences. In in vitro biofilm assays, the mutant strain showed a significantly higher level of growth medium-specific biofilm formation compared to the wild type. However, in a murine intraperitoneal infection model, the mutant strain was significantly less pathogenic. The mutant was also attenuated for survival within macrophages in vitro. These findings highlight the importance of PerA as a regulator of biofilm formation and survival within macrophages and is likely a regulator controlling determinants important to pathogenesis. PMID:18824537

  6. Characterization of the Deoxynucleotide Triphosphate Triphosphohydrolase (dNTPase) Activity of the EF1143 Protein from Enterococcus faecalis and Crystal Structure of the Activator-Substrate Complex

    SciTech Connect

    Vorontsov, Ivan I.; Minasov, George; Kiryukhina, Olga; Brunzelle, Joseph S.; Shuvalova, Ludmilla; Anderson, Wayne F.

    2012-06-19

    The EF1143 protein from Enterococcus faecalis is a distant homolog of deoxynucleotide triphosphate triphosphohydrolases (dNTPases) from Escherichia coli and Thermus thermophilus. These dNTPases are important components in the regulation of the dNTP pool in bacteria. Biochemical assays of the EF1143 dNTPase activity demonstrated nonspecific hydrolysis of all canonical dNTPs in the presence of Mn{sup 2+}. In contrast, with Mg{sup 2+} hydrolysis required the presence of dGTP as an effector, activating the degradation of dATP and dCTP with dGTP also being consumed in the reaction with dATP. The crystal structure of EF1143 and dynamic light scattering measurements in solution revealed a tetrameric oligomer as the most probable biologically active unit. The tetramer contains four dGTP specific allosteric regulatory sites and four active sites. Examination of the active site with the dATP substrate suggests an in-line nucleophilic attack on the {alpha}-phosphate center as a possible mechanism of the hydrolysis and two highly conserved residues, His-129 and Glu-122, as an acid-base catalytic dyad. Structural differences between EF1143 apo and holo forms revealed mobility of the {alpha}3 helix that can regulate the size of the active site binding pocket and could be stabilized in the open conformation upon formation of the tetramer and dGTP effector binding.

  7. The annotated complete DNA sequence of Enterococcus faecalis bacteriophage φEf11 and its comparison with all available phage and predicted prophage genomes.

    PubMed

    Stevens, Roy H; Ektefaie, Mahmoud R; Fouts, Derrick E

    2011-04-01

    φEf11 is a temperate Siphoviridae bacteriophage isolated by induction from a lysogenic Enterococcus faecalis strain. The φEf11 DNA was completely sequenced and found to be 42,822 bp in length, with a G+C mol% of 34.4%. Genome analysis revealed 65 ORFs, accounting for 92.8% of the DNA content. All except for seven of the ORFs displayed sequence similarities to previously characterized proteins. The genes were arranged in functional modules, organized similar to that of several other phages of low GC Gram-positive bacteria; however, the number and arrangement of lysis-related genes were atypical of these bacteriophages. A 159 bp noncoding region between predicted cI and cro genes is highly similar to the functionally characterized early promoter region of lactococcal temperate phage TP901-1, and possessed a predicted stem-loop structure in between predicted P(L) and P(R) promoters, suggesting a novel mechanism of repression of these two bacteriophages from the λ paradigm. Comparison with all available phage and predicted prophage genomes revealed that the φEf11 genome displays unique features, suggesting that φEf11 may be a novel member of a larger family of temperate prophages that also includes lactococcal phages. Trees based on the blast score ratio grouped this family by tail fiber similarity, suggesting that these trees are useful for identifying phages with similar tail fibers.

  8. RNA of Enterococcus faecalis Strain EC-12 Is a Major Component Inducing Interleukin-12 Production from Human Monocytic Cells

    PubMed Central

    Nishibayashi, Ryoichiro; Inoue, Ryo; Harada, Yuri; Watanabe, Takumi; Makioka, Yuko; Ushida, Kazunari

    2015-01-01

    Interleukin-12 (IL-12) is an important cytokine for the immunomodulatory effects of lactic acid bacteria (LAB). Using murine immune cells, we previously reported that the RNA of Enterococcus faecalis EC-12, a LAB strain exerting probiotic-like beneficial effects, is the major IL-12-inducing immunogenic component. However, it was recently revealed that bacterial RNA can be a ligand for Toll-like receptor (TLR) 13, which is only expressed in mice. Because TLR13 is not expressed in humans, the immuno-stimulatory and -modulatory effects of LAB RNA in human cells should be augmented excluding TLR13 contribution. In experiment 1 of this study, the role of LAB RNA in IL-12 induction in human immune cells was studied using three LAB strains, E.faecalis EC-12, Lactobacillus gasseri JCM5344, and Bifidobacterium breve JCM1192. RNase A treatment of heat-killed LAB significantly decreased the IL-12 production of human peripheral blood mononuclear cells on stimulation, while RNase III treatment revealed virtually no effects. Further, IL-12 production against heat-killed E. faecalis EC-12 was abolished by depleting monocytes. These results demonstrated that single stranded RNA (ssRNA) of LAB is a strong inducer of IL-12 production from human monocytes. In experiment 2, major receptor for ssRNA of E. faecalis EC-12 was identified using THP-1 cells, a human monocytic cell line. The type of RNA molecules of E. faecalis EC-12 responsible for IL-12 induction was also identified. IL-12 production induced by the total RNA of E. faecalis EC-12 was significantly reduced by the treatment of siRNA for TLR8 but not for TLR7. Furthermore, both 23S and 16S rRNA, but not mRNA, of E. faecalis EC-12 markedly induced IL-12 production from THP-1 cells. These results suggested that the recognition of ssRNA of E. faecalis EC-12 was mediated by TLR8 and that rRNA was the RNA molecule that exhibited IL-12-inducing ability in human cells. PMID:26083838

  9. Australian Group on Antimicrobial Resistance Enterococcus Surveillance Programme annual report, 2010.

    PubMed

    Coombs, Geoffrey W; Pearson, Julie C; Christiansen, Keryn; Gottlieb, Thomas; Bell, Jan M; George, Narelle; Turnidge, John D

    2013-09-30

    In 2010, 15 institutions around Australia conducted a period prevalence study of key resistances in isolates of Enterococcus species associated with a range of clinical disease amongst in- and outpatients. Each institution collected up to 100 consecutive isolates and tested these for susceptibility to commonly used antimicrobials using standardised methods. Vancomycin-resistant Enterococcus faecium and Enterococcus faecalis were characterised by pulsed-field gel electrophoresis. Multilocus sequence typing was performed on representative pulsotypes of E. faecium. Susceptibility results were compared with similar surveys conducted in 1995, 1999, 2003, 2005, 2007 and 2009. In the 2010 survey, E. faecalis (1,201 isolates) and E. faecium (170 isolates) made up 98.9% of the 1,386 isolates tested. Ampicillin resistance was very common (85.3%) in E. faecium and absent in E. faecalis. Non-susceptibility to vancomycin was 36.5% in E. faecium (similar to the 35.2% in 2009 but up from 15.4% in the 2007 survey) and 0.5% in E. faecalis. There were significant differences in the proportion of vancomycin-resistant E. faecium between the states ranging from 0% in Western Australia to 54.4% in South Australia. The vanB gene was detected in 62 E. faecium and 3 E. faecalis isolates. The vanA gene was detected in 1 E. faecium isolate. All vancomycin-resistant E. faecium belonged to clonal complex 17. The most common sequence type (ST) was ST203, which was found in all regions that had reports of vancomycin resistant enterococci. ST341 was detected only in New South Wales/Australian Capital Territory and ST414 only in South Australia and Victoria. High-level resistance to gentamicin was 34.1% in E. faecalis and 66.1% in E. faecium. A subset of isolates was tested against high-level streptomycin, linezolid and quinupristin/dalfopristin. High-level streptomycin resistance was found in 8.2% of E. faecalis isolates and 43.8% of E. faecium isolates. Linezolid non

  10. Population biology of intestinal enterococcus isolates from hospitalized and nonhospitalized individuals in different age groups.

    PubMed

    Tedim, Ana P; Ruiz-Garbajosa, Patricia; Corander, Jukka; Rodríguez, Concepción M; Cantón, Rafael; Willems, Rob J; Baquero, Fernando; Coque, Teresa M

    2015-03-01

    The diversity of enterococcal populations from fecal samples from hospitalized (n = 133) and nonhospitalized individuals (n = 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages ≥60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium

  11. Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

    PubMed Central

    Tedim, Ana P.; Ruiz-Garbajosa, Patricia; Corander, Jukka; Rodríguez, Concepción M.; Cantón, Rafael; Willems, Rob J.; Baquero, Fernando

    2014-01-01

    The diversity of enterococcal populations from fecal samples from hospitalized (n = 133) and nonhospitalized individuals (n = 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages ≥60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium

  12. Isolation and characterization of tyramine-producing Enterococcus faecium strains from red wine.

    PubMed

    Capozzi, Vittorio; Ladero, Victor; Beneduce, Luciano; Fernández, María; Alvarez, Miguel A; Benoit, Bach; Laurent, Barnavon; Grieco, Francesco; Spano, Giuseppe

    2011-05-01

    Enterococcus faecium strains were isolated from red wines undergoing malolactic fermentation and identified by comparison of their 16S rDNA gene sequences with those included in the GenEMBL Databases. The tyrosine decarboxylase gene was identified in all the strains analysed by PCR using gene-specific primers and the ability to produce tyramine in a synthetic media was analysed by RP-HPLC. Survival of an E. faecium strain was also evaluated in microvinification assays using two different musts with different ethanol concentrations (10% and 12% (v/v)). Tyramine production was monitored during the vinification trials. Our results suggest that E. faecium strains isolated from wine are able to produce tyramine and tolerate wine conditions following a pre-acidic stress.

  13. [Detection of vancomycin-resistant Enterococcus faecium: 2 years' experience in a high complexity hospital ].

    PubMed

    Lopreto, C R; Viegas Caetano, J A; Padlog, R; Sorgentini, M; Bardi, C; Silvestri, C

    2002-01-01

    The presence of vancomycin-resistant enterococci (VRE) in our hospital prompted us to apply an appropriate method for assessing its rectal carriage. A screening method with bile-esculin azide agar plus different concentrations of vancomycin was used. The antimicrobial susceptibility study of enterococci isolated from clinical samples was also emphasized. The present study includes the surveillance and detection of VRE in our hospital during two years. A total of 260 samples corresponding to 138 patients were studied, 158 of them resulting positive. All EVR were Van A Enterococcus faecium, with MICs of vancomycin > or = 256 micrograms/ml. The analysis of susceptibility patterns shows variations with chloramphenicol, tetracycline and high level gentamicin concentrations. This method was easily applied because materials could be available in any clinical microbiology laboratory, and in our hands it has demonstrated to be useful for epidemiological surveillance for EVR.

  14. Detection of vanA-Containing Enterococcus Species in Faecal Microbiota of Gilthead Seabream (Sparus aurata)

    PubMed Central

    Barros, Joana; Andrade, Margarida; Radhouani, Hajer; López, Maria; Igrejas, Gilberto; Poeta, Patricia; Torres, Carmen

    2012-01-01

    Vancomycin-resistant Enterococcus faecalis, E. faecium and E. durans isolates with the genotype vanA were detected in 7 of 118 faecal samples (5.9%) of natural gilthead seabream recovered off the coast of Portugal, and one vancomycin-resistant isolate/sample was further characterized. The genes erm(B), tet(L), tet(M), aac(6′)-aph(2″), aph(3′)-IIIa and/or ant(6)-Ia were identified in most of the 7 vancomycin-resistant enterococci. Sequence types ST273, ST313 and ST76 were detected in three E. faecium isolates and ST6 in two E. faecalis isolates. VanA-containing enterococci are suggested to be disseminated in fish in marine ecosystems close to areas of human activity. PMID:22641152

  15. Nucleotide substitutions in vanC-2 gene of Enterococcus casseliflavus isolates obtained from chickens.

    PubMed Central

    Murase, T.; Mito, Y.; Otsuki, K.; Suzuki, R.; Yamai, S.

    2002-01-01

    DNA sequencing of the vanC-2 gene was partially carried out on 10 isolates of Enterococcus casseliflavus obtained from 8 samples of imported chickens in Japan between July 1999 and June 2001 to evaluate the variation in the gene. Forty nucleotide substitutions in 36 codons were identified within 345 base pairs when compared with the vanC-2 sequence of the reference strain E. casseliflavus ATCC25788. Identical nucleotide substitutions were commonly found in the isolates recovered from chickens imported from both Brazil and China. Pulsed-field gel electrophoresis (PFGE) patterns of NotI-digested chromosomal DNA of these strains were distinguished by two, or more than six, band differences. These observations suggest that sequencing of the vanC-2 gene may be helpful for epidemiological investigation in combination with the PFGE analyses of the isolates, although particular genotypes are unlikely to be restricted to each of the countries that exported chickens. PMID:12403118

  16. Contribution of the enterococcal surface protein Esp to pathogenesis of Enterococcus faecium endocarditis.

    PubMed

    Heikens, Esther; Singh, Kavindra V; Jacques-Palaz, Karen D; van Luit-Asbroek, Miranda; Oostdijk, Evelien A N; Bonten, Marc J M; Murray, Barbara E; Willems, Rob J L

    2011-12-01

    The enterococcal surface protein Esp, specifically linked to nosocomial Enterococcus faecium, is involved in biofilm formation. To assess the role of Esp in endocarditis, a biofilm-associated infection, an Esp-expressing E. faecium strain (E1162) or its Esp-deficient mutant (E1162Δesp) were inoculated through a catheter into the left ventricle of rats. After 24 h, less E1162Δesp than E1162 were recovered from heart valve vegetations. In addition, anti-Esp antibodies were detected in Esp-positive E. faecium bacteremia and endocarditis patient sera. In conclusion, Esp contributes to colonization of E. faecium at the heart valves. Furthermore, systemic infection elicits an Esp-specific antibody response in humans.

  17. Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene esp.

    PubMed

    Lund, B; Billström, H; Edlund, C

    2006-06-01

    This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp-) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp- isolates (p < 0.001), with a median value of 6.4 x 10(-6) transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments.

  18. Treatment of enterococcus faecalis bacteria by a helium atmospheric cold plasma brush with oxygen addition

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Huang, Jun; Du, Ning; Liu, Xiao-Di; Wang, Xing-Quan; Lv, Guo-Hua; Zhang, Guo-Ping; Guo, Li-Hong; Yang, Si-Ze

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed. Results demonstrate that the He/O2 plasma more effectively kills Enterococcus faecalis than the pure He plasma. In addition, the sterilization efficiency values of the He/O2 plasma depend on the oxygen fraction in Helium gas. The atmospheric cold plasma brush using a proper ratio of He/O2 (2.5%) reaches the optimum sterilization efficiency. After plasma treatment, the cell structure and morphology changes can be observed by the scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  19. Occurrence of Enterococcus species with virulence markers in an urban flow-influenced tropical recreational beach.

    PubMed

    Ahmad, Asmat; Dada, Ayokunle Christopher; Usup, Gires; Heng, Lee Yook

    2014-05-15

    Median enterococci counts of beach water samples gradually increased at statistically significant levels (χ2: 26.53, df: 4; p<0.0001) with increasing proximity to river influx. The difference in proportion of antibiotic resistant enterococci in beach water and river water samples was statistically significant (p<0.05) for the tested antibiotics with river isolates generally presenting higher resistance frequencies. Virulence genes cyl, esp, gelE and asa were detected at varying frequencies (7.32%, 21.95%, 100% and 63.41% respectively) among river isolates. On the other hand, the prevalence of these genes was lower (0%, 20%, 67.27% and 41.82% respectively) among beach water isolates. Multi-Locus-Sequence-Typing analysis of Enterococcus faecalis presented four sequence types (ST) one of which shared six out of seven tested loci with ST6, a member of the clonal complex of multi-drug resistant strains associated with hospital outbreaks.

  20. Cloning, purification, crystallization and preliminary crystallographic analysis of SecA from Enterococcus faecalis

    SciTech Connect

    Meining, Winfried; Scheuring, Johannes; Fischer, Markus; Weinkauf, Sevil

    2006-06-01

    SecA ATPase from E. faecalis has been cloned, overexpressed, purified and crystallized. Crystals belong to space group C2 and diffract to 2.4 Å resolution. The gene coding for SecA from Enterococcus faecalis was cloned and overexpressed in Escherichia coli. In this protein, the lysine at position 6 was replaced by an asparagine in order to reduce sensitivity towards proteases. The modified protein was purified and crystallized. Crystals diffracting to 2.4 Å resolution were obtained using the vapour-diffusion technique. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 203.4, b = 49.8, c = 100.8 Å, α = γ = 90.0, β = 119.1°. A selenomethionine derivative was prepared and is currently being tested in crystallization trials.

  1. Treatment of enterococcus faecalis bacteria by a helium atmospheric cold plasma brush with oxygen addition

    SciTech Connect

    Chen Wei; Huang Jun; Wang Xingquan; Lv Guohua; Zhang Guoping; Du Ning; Liu Xiaodi; Guo Lihong; Yang Size

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed. Results demonstrate that the He/O{sub 2} plasma more effectively kills Enterococcus faecalis than the pure He plasma. In addition, the sterilization efficiency values of the He/O{sub 2} plasma depend on the oxygen fraction in Helium gas. The atmospheric cold plasma brush using a proper ratio of He/O{sub 2} (2.5%) reaches the optimum sterilization efficiency. After plasma treatment, the cell structure and morphology changes can be observed by the scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  2. Effect of NaCl Treatments on Tyramine Biosynthesis of Enterococcus faecalis.

    PubMed

    Liu, Fang; Wang, Xinxin; Du, Lihui; Wang, Daoying; Zhu, Yongzhi; Geng, Zhiming; Xu, Xiaoxi; Xu, Weimin

    2015-05-01

    The effect of NaCl stress (0 to 8%, wt/vol) on the growth and tyramine production in two Enterococcus faecalis strains was examined during culture time. The growth of E. faecalis was inhibited by the increase in NaCl concentration, but tyramine production was unaffected. Tyramine accumulated rapidly during the logarithmic phase of the strains, and the final tyramine levels were approximately 800 μg/ml. Relative gene expression of four genes in the tyrosine decarboxylase locus, namely, tyrRS, tyrDC, tyrP, and nhaC, was evaluated at different incubation times. The results showed that NaCl stress could upregulate the expression of tyrDC and tyrP to improve the tyramine production of a single E. faecalis strain under certain conditions, and TyrS could act as a negative regulator on the genetic regulation of the tyramine cluster.

  3. The surface rhamnopolysaccharide epa of Enterococcus faecalis is a key determinant of intestinal colonization.

    PubMed

    Rigottier-Gois, Lionel; Madec, Clément; Navickas, Albertas; Matos, Renata C; Akary-Lepage, Elodie; Mistou, Michel-Yves; Serror, Pascale

    2015-01-01

    Enterococcus faecalis is a commensal bacterium of the human intestine and a major opportunistic pathogen in immunocompromised and elderly patients. The pathogenesis of E. faecalis infection relies in part on its capacity to colonize the gut. Following disruption of intestinal homeostasis, E. faecalis can overgrow, cross the intestinal barrier, and enter the lymph and bloodstream. To identify and characterize E. faecalis genes that are key to intestinal colonization, our strategy consisted in screening mutants for the following phenotypes related to intestinal lifestyle: antibiotic resistance, overgrowth, and competition against microbiota. From the identified colonization genes, epaX encodes a glycosyltransferase located in a variable region of the enterococcal polysaccharide antigen (epa) locus. We demonstrated that EpaX acts on sugar composition, promoting resistance to bile salts and cell wall integrity. Given that EpaX is enriched in hospital-adapted isolates, this study points to the importance of the epa variability as a key determinant for enterococcal intestinal colonization.

  4. Enterococcus Faecalis Biofilm. Formation and Development in Vitro Observed by Scanning Electron Microscopy.

    PubMed

    Bulacio, María de Los Á; Galván, Lucas R; Gaudioso, Cristina; Cangemi, Rosa; Erimbaue, Marta I

    2015-12-01

    Biofilm produced by Enterococcus faecalis isolated from root canals was detected by growing it on microplates and using 10% crystal violet stain, elution with alcohol and three procedures: no fixation, heat fixation and 10% formaldehyde fixation. The biofilm was evaluated using a Versamax Microplate Reader (USA). Twenty sterile root portions were incubated in TS broth with E. faecalis (108) for 48 hours, 4, 7, 14 and 30 days, after which they were processed and observed by scanning electron microscopy (SEM). Significantly more biofilm was found on the microplates for formaldehyde fixation than for heat fixation or no fixation (ANOVA p<0.0001). SEM showed E. faecalis growth at all times and biofilm development as from 14 days' incubation. Fixation with 10% formaldehyde was the most appropriate technique for detecting E. faecalis biofilm development on microplates. SEM confirmed biofilm formation after 14 days incubation.

  5. [Infections caused by multi-resistant Gram-positive bacteria (Staphylococcus aureus and Enterococcus spp.)].

    PubMed

    Cantón, Rafael; Ruiz-Garbajosa, Patricia

    2013-10-01

    Methicillin -resistant Staphylocccus aureus (MRSA) and multirresistant entorococci are still problematic in nosocomial infections and new challenges have emerged for their containment. MRSA has increased the multiresistant profile; it has been described vancomycin and linezolid resistant isolates and isolates with decreased daptomycin susceptibility. Moreover, new clones (ST398) have emerged, initially associated with piggeries, and new mec variants (mecC) with livestock origin that escape to the detection with current molecular methods based on mecA gene have been detected. In enterococci, linzeolid resistant isolates and isolates with deceased susceptibility to daptomycin have been described. Moreover, ampicillin resistant Enterococcus faecium due to β-lactamase production has been recently found in Europe. Control of MRSA isolates and multiresistant enteroccocci should combined antibiotic stewardship strategies and epidemiological measures, including detection of colonized patients in order to reduce colonization pressure and their transmission.

  6. In vitro antimicrobial effect of bacteriophages on human dentin infected with Enterococcus faecalis ATCC 29212.

    PubMed

    Paisano, A F; Spira, B; Cai, S; Bombana, A C

    2004-10-01

    This study assessed the effect of bacteriophages on the viability of Enterococcus faecalis. Human dental roots were inoculated with a suspension of E. faecalis at three different multiplicities of infection - 0.1, 1.0 and 10.0. The phage lysate was able to significantly inhibit bacteria growth when incubated at the multiplicities of infection of 1.0, 10.0 and 0.1. The dental roots were also inoculated with bacteria for 6 days to allow bacterial penetration into the teeth tubules. Addition of the phage lysate to the roots following the 6-day incubation period led to a substantial reduction in bacteria viability. Phage therapy may be an important alternative for the treatment of root canal infections refractory to conventional endodontic therapy.

  7. The effect of berberine hydrochloride on Enterococcus faecalis biofilm formation and dispersion in vitro.

    PubMed

    Chen, Lihua; Bu, Qianqian; Xu, Huan; Liu, Yuan; She, Pengfei; Tan, Ruichen; Wu, Yong

    2016-01-01

    Enterococcus faecalis (E. faecalis) is one of the major causes of biofilm infections. Berberine hydrochloride (BBH) has diverse pharmacological effects; however, the effects and mechanisms of BBH on E. faecalis biofilm formation and dispersion have not been reported. In this study, 99 clinical isolates from the urine samples of patients with urinary tract infections (UTIs) were collected and identified. Ten strains of E. faecalis with biofilm formation ability were studied. BBH inhibited E. faecalis biofilm formation and promoted the biofilm dispersion of E. faecalis. In addition, sortase A and esp expression levels were elevated during early E. faecalis biofilm development, whereas BBH significantly reduced their expression levels. The results of this study indicated that BBH effectively prevents biofilm formation and promotes biofilm dispersion in E. faecalis, most likely by inhibiting the expressions of sortase A and esp.

  8. Microbial Flora of Root Canals of Pulpally-infected Teeth: Enterococcus faecalis a Prevalent Species

    PubMed Central

    Gajan, Esrafil Balaei; Aghazadeh, Mohammad; Abashov, Rahib; Salem Milani, Amin; Moosavi, Zohreh

    2009-01-01

    Background and aims The aim of this study was to determine the microorganisms prevalent in the necrotic dental pulp and root canals of unsuccessfully treated teeth. Materials and methods The present study was conducted on 150 single-rooted teeth of patients referring to a dental clinic. Sampling was performed by placing a sterile paper point in the canal for 60 s. Bacterial samples were evaluated by a microbiological technique specific for anaerobic species, used for isolation and identification of sampled strains. Results From the 150 samples taken, 101 were from necrotic pulps (primary infection) and 49 were from the teeth with an unsuccessful endodontic treatment (secondary infection). Conclusion Enterococcus faecalis was a prevalent species in the failed root canals evaluated. PMID:23230477

  9. [In vitro activity of ampicillin-ceftriaxone against Enterococcus faecalis isolates recovered from invasive infections].

    PubMed

    Burguer Moreira, Noelia; Nastro, Marcela; Vay, Carlos; Famiglietti, Ángela; Rodríguez, Carlos Hernán

    2016-01-01

    In vitro activity of the combination of ampicillin- ceftriaxone against 30 Enterococcus faecalis isolates recovered from invasive infections in patients admitted to Hospital de Clínicas José de San Martin in the city of Buenos Aires was assessed. Ampicillin- ceftriaxone synergies were determined by microdilution in Müeller-Hinton (MH) broth with and without subinhibitory concentrations of ceftriaxone. Synergy was detected in 22/30 isolates. A decrease in both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was observed in 14/30 isolates, whereas in 6/30 isolates the decrease was observed in the MIC value and only in the MBC value in the 2 remaining isolates. The bactericidal activity of the combination showed to be higher at low concentrations of ampicillin (< 1 μg/ml). We detected in vitro synergy using the ampicillin-ceftriaxone combination and thus, its efficacy was confirmed in the treatment of severe infections by E. faecalis.

  10. Novel antibiotic regimens against Enterococcus faecium resistant to ampicillin, vancomycin, and gentamicin.

    PubMed Central

    Landman, D; Mobarakai, N K; Quale, J M

    1993-01-01

    Enterococci have emerged as significant nosocomial pathogens. Enterococci with resistance to commonly used antibiotics are appearing more frequently. We encountered at our institution several infections caused by Enterococcus faecium with high-level resistance to ampicillin, vancomycin, and gentamicin. The optimal antibiotic therapy for serious infections with unusually resistant enterococci has not been established. Using time-kill studies, we tested the effectiveness of various antibiotic combinations against 15 isolates of multidrug-resistant enterococci. No antibiotic was consistently effective when used alone. The combination of ampicillin plus ciprofloxacin was bactericidal for the 12 isolates for which the ciprofloxacin MIC was < or = 8 micrograms/ml. The combination of ciprofloxacin plus novobiocin also demonstrated activity against these isolates. No combination was found to be bactericidal for the remaining three isolates, which were highly ciprofloxacin resistant. These antibiotic combinations may be important for the future treatment of serious infections caused by these resistant pathogens. PMID:8239604

  11. Transcriptomic response of Enterococcus faecalis V583 to low hydrogen peroxide levels.

    PubMed

    Yan, Xue; Budin-Verneuil, Aurélie; Verneuil, Nicolas; Gilmore, Michael S; Artigaud, Sébastien; Auffray, Yanick; Pichereau, Vianney

    2015-02-01

    Enterococcus faecalis is a Gram-positive commensal bacterium inhabiting the gastrointestinal tracts of human and other mammals, but is also increasingly recognized as an opportunistic human pathogen. Oxidative stress is one of the major challenges encountered by enterococci, both in their natural environment and during infection. In this paper, we evaluated the transcriptomic response of E. faecalis to oxidative stress, and showed that transcript abundance was reduced for 93 genes and increased for 39 genes during growth in medium containing 1.75 mM H2O2. The presence of hydrogen peroxide affected several metabolic pathways, including a large decrease in ethanolamine utilization and methylglyoxal metabolism, and an increase in transcript abundance for several transport systems. In particular, four operons encoding iron transporters appeared highly induced. By contrast, in our experimental conditions, the expression of most of the genes known to be involved in the enterococcal response to oxidative stress, did not appear significantly altered.

  12. Bacteriocin Production in Vancomycin-Resistant and Vancomycin-Susceptible Enterococcus Isolates of Different Origins

    PubMed Central

    Del Campo, Rosa; Tenorio, Carmen; Jiménez-Díaz, Rufino; Rubio, Carmen; Gómez-Lus, Rafael; Baquero, Fernando; Torres, Carmen

    2001-01-01

    Bacteriocin production was determined for 218 Enterococcus isolates (Enterococcus faecalis [93] and E. faecium [125]) obtained from different origins (human clinical samples [87], human fecal samples [78], sewage [28], and chicken samples [25]) and showing different vancomycin susceptibility patterns (vancomycin resistant, all of them vanA positive [56], and vancomycin susceptible [162]). All enterococcal isolates were randomly selected except for the vancomycin-resistant ones. A total of 33 isolates of eight different bacterial genera were used as indicators for bacteriocin production. Forty-seven percent of the analyzed enterococcal isolates were bacteriocin producers (80.6% of E. faecalis and 21.6% of E. faecium isolates). The percentage of bacteriocin producers was higher among human clinical isolates (63.2%, 81.8% of vancomycin-resistant isolates and 60.5% of vancomycin-susceptible ones) than among isolates from the other origins (28 to 39.3%). Only one out of the 15 vancomycin-resistant isolates from human fecal samples was a bacteriocin producer, while 44.4% of fecal vancomycin-susceptible isolates were. The bacteriocin produced by the vanA-containing E. faecium strain RC714, named bacteriocin RC714, was further characterized. This bacteriocin activity was cotransferred together with the vanA genetic determinant to E. faecalis strain JH2-2. Bacteriocin RC714 was purified to homogeneity and its primary structure was determined by amino acid sequencing, showing an identity of 88% and a similarity of 92% with the previously described bacteriocin 31 from E. faecalis YI717. The presence of five different amino acids in bacteriocin RC714 suggest that this could be a new bacteriocin. The results obtained suggest that the epidemiology of vancomycin resistance may be influenced by different factors, including bacteriocin production. PMID:11181378

  13. Proficiency of Clinical Laboratories in Spain in Detecting Vancomycin-Resistant Enterococcus spp.

    PubMed Central

    Alonso-Echanove, Juan; Robles, Belen; Jarvis, William R.

    1999-01-01

    Studies in a variety of U.S. clinical laboratories have demonstrated difficulty in detecting intermediate and low-level vancomycin-resistant enterococci (VRE). The misclassification of “at least intermediate resistant isolates” as vancomycin susceptible may have both clinical implications and a negative impact on measures to control the spread of VRE. No published study has assessed the ability of clinical laboratories in Europe to detect VRE. So, the apparent low prevalence of VRE in European hospitals may be, in part, secondary to the inability of these laboratories to detect all VRE. In an effort to assess European laboratories’ proficiency in detecting VRE, we identified 22 laboratories in Spain and asked them to test four VRE strains and one susceptible enterococcal strain from the Centers for Disease Control and Prevention collection. Each organism was tested by the routine antimicrobial susceptibility testing method used by each laboratory. Overall, VRE were correctly identified in 61 of 88 (69.1%) instances. The accuracy of VRE detection varied with the level of resistance and the antimicrobial susceptibility method. The high-level-resistant strain (Enterococcus faecium; MIC, 512 μg/ml) was accurately detected in 20 of 22 (91.3%) instances, whereas the intermediate-resistant isolate (Enterococcus gallinarum; MIC, 8 μg/ml) was accurately detected in only 11 of 22 (50%) instances. Classification errors occurred in 27 of 88 (30.9%) instances. Misclassification as vancomycin susceptible was the most common error (16 of 27 [59.3%] instances). Our study shows that the participating Spanish laboratories had an overall acceptable proficiency in detecting VRE but that a substantial proportion of VRE isolates with low or intermediate levels of resistance were not detected. We recommend that studies be conducted to validate laboratory proficiency testing as an important step in the prevention and control of the spread of antimicrobial resistance. PMID:10364577

  14. Incidence of Type II CRISPR1-Cas Systems in Enterococcus Is Species-Dependent

    PubMed Central

    Lyons, Casandra; Raustad, Nicole; Bustos, Mario A.; Shiaris, Michael

    2015-01-01

    CRISPR-Cas systems, which obstruct both viral infection and incorporation of mobile genetic elements by horizontal transfer, are a specific immune response common to prokaryotes. Antiviral protection by CRISPR-Cas comes at a cost, as horizontally-acquired genes may increase fitness and provide rapid adaptation to habitat change. To date, investigations into the prevalence of CRISPR have primarily focused on pathogenic and clinical bacteria, while less is known about CRISPR dynamics in commensal and environmental species. We designed PCR primers and coupled these with DNA sequencing of products to detect and characterize the presence of cas1, a universal CRISPR-associated gene and proxy for the Type II CRISPR1-Cas system, in environmental and non-clinical Enterococcus isolates. CRISPR1-cas1 was detected in approximately 33% of the 275 strains examined, and differences in CRISPR1 carriage between species was significant. Incidence of cas1 in E. hirae was 73%, nearly three times that of E. faecalis (23.6%) and 10 times more frequent than in E. durans (7.1%). Also, this is the first report of CRISPR1 presence in E. durans, as well as in the plant-associated species E. casseliflavus and E. sulfureus. Significant differences in CRISPR1-cas1 incidence among Enterococcus species support the hypothesis that there is a tradeoff between protection and adaptability. The differences in the habitats of enterococcal species may exert varying selective pressure that results in a species-dependent distribution of CRISPR-Cas systems. PMID:26600384

  15. Gene transfer of vancomycin and tetracycline resistances among Enterococcus faecalis during cheese and sausage fermentations.

    PubMed

    Cocconcelli, Pier Sandro; Cattivelli, Daniela; Gazzola, Simona

    2003-12-01

    This study assessed the frequency of transfer of two mobile genetic elements coding for virulence determinants and antibiotic resistance factors, into food associated enterococci during fermentation processes. First, the transfer of the pheromone-inducible pCF10 plasmid, carrying tetracycline resistance and aggregation substance (AS) as virulence factor, between clinical and food strains of Enterococcus faecalis, was investigated in models of cheese and fermented sausage. The experiments demonstrated that even in the absence of selective tetracycline pressure, plasmid pCF10 was transferred from E. faecalis OG1rf cells to food strain E. faecalis BF3098c and that the plasmid subsequently persisted in these environments. Very high frequency of transfer was observed in sausage (10(-3)/recipient) if compared to cheese (10(-6)) and plate mating (10(-4)). Transconjugants were subsequently verified by PCR. The second transmissible element was the plasmid harbouring the vancomycin resistance (VanA phenotype) from E. faecalis A256. The transfer of this antibiotic resistance to a food strain of E. faecalis was studied in vitro and in food models. Although the transfer of vancomycin resistance was achieved in all the environments, the highest conjugation frequencies were observed during the ripening of fermented sausages, reaching 10(-3) transconjugants/recipient cell. PCR confirmed the transfer of the VanA genotype into a food associated Enterococcus strain. This study showed that even in the absence of selective pressure, mobile genetic elements carrying antibiotic resistance and virulence determinants can be transferred at high frequency to food associated enterococci during cheese and sausage fermentation.

  16. Selection of potential probiotic Enterococcus faecium isolated from Portuguese fermented food.

    PubMed

    Barbosa, Joana; Borges, Sandra; Teixeira, Paula

    2014-11-17

    Four Enterococcus faecium strains isolated from fermented products were evaluated for potential use as probiotic strains. In addition to efaAfm gene, commonly found in E. faecium food isolates, none of the isolates possessed virulence genes and none had positive reactions for the production of tyramine, histamine, putrescine and cadaverine in the screening medium used. All of these four isolates proved to be resistant to 65 °C. E. faecium 119 did not show antimicrobial activity against any of the target bacteria investigated. E. faecium 85 and 101 inhibited Listeria innocua and E. faecium DSMZ 13590. The strain E. faecium 120 inhibited seven target bacteria (Listeria monocytogenes 7946, L. monocytogenes 7947, L. innocua 2030c, L. innocua NCTC 11286, E. faecium DSMZ 13590, Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 29213) and was chosen as the representative to assess the ability to survive gastrointestinal tract passage simulation, as well as the protective role of two food matrices (skim milk and Alheira) during its passage. For both matrices used, no significant differences (p<0.05) were obtained between the types of digestion - quick and slow passage simulation. In the skim milk matrix the isolate was reduced to values below the detection limit of the enumeration technique by the end of the two digestions, in contrast to the Alheira matrix, for which isolate 120 showed a reduction of only ca. 1 log CFU/ml. The E. faecium strain 120 was shown to be a potential candidate for further investigations as a potential probiotic culture.

  17. Draft Genome Sequence of the Bacteriocin-Producing Strain Enterococcus faecium M3K31, Isolated from Griffon Vultures (Gyps fulvus subsp. fulvus).

    PubMed

    Arbulu, Sara; Frantzen, Cyril; Lohans, Christopher T; Cintas, Luis M; Herranz, Carmen; Holo, Helge; Diep, Dzung B; Vederas, John C; Hernández, Pablo E

    2016-03-24

    Enterococcus faeciumM3K31 is a bacteriocinogenic lactic acid bacterium (LAB) isolated from griffon vulture (Gyps fulvussubsp.fulvus) feces. The draft genome sequence of this strain provides genetic data that support its biotechnological potential.

  18. Draft Genome Sequence of the Bacteriocin-Producing Strain Enterococcus faecium M3K31, Isolated from Griffon Vultures (Gyps fulvus subsp. fulvus)

    PubMed Central

    Arbulu, Sara; Frantzen, Cyril; Lohans, Christopher T.; Cintas, Luis M.; Herranz, Carmen; Holo, Helge; Diep, Dzung B.; Vederas, John C.

    2016-01-01

    Enterococcus faecium M3K31 is a bacteriocinogenic lactic acid bacterium (LAB) isolated from griffon vulture (Gyps fulvus subsp. fulvus) feces. The draft genome sequence of this strain provides genetic data that support its biotechnological potential. PMID:27013035

  19. Prevalence and antibiotic-resistance characteristics of Enterococcus spp. Isolated from free-living and captive raptors in Central Illinois.

    PubMed

    Marrow, Judilee; Whittington, Julia K; Mitchell, Mark; Hoyer, Lois L; Maddox, Carol

    2009-04-01

    Due to their predatory nature, raptor species may serve as important indicators of environmental contamination with antimicrobial-resistant bacteria. Raptors prey on small rodents and birds that have diverse habitat ranges, including urban and rural environments, and their intestinal microflora can reflect that of the animals on which they feed. Enterococcus spp. were selected as target organisms because they have been isolated from the avian gastrointestinal tract, can be conferred by prey items, and because they are capable of multiple resistance patterns. They are also a concerning source of human antimicrobial resistance. In this study fecal cultures were obtained from 15 May 2004 to 31 August 2004, from 21 free-living raptors and four captive raptors. Enterococcus was isolated from 21 (84%) of the 25 birds, and 54 isolates were chosen for further study based upon unique colony morphology. The most common isolate recovered was Enterococcus faecalis (95%, 95% confidence interval [CI]: 89-100). One bird in the study was determined to have Enterococcus gallinarum. Two distinct ribotypes of E. faecalis were identified, one with unique bands at 11 and 13 kb and the other with unique bands at 14 and 20 kb. Both ribotypes were found in free-living and captive birds. The Enterococcus isolates in this study demonstrated a variety of antimicrobial-resistance characteristics, including almost complete resistance to amikacin, first-generation cephalosporins, spectinomycin, and sulphadimethoxime. Isolates demonstrated variable resistance to chloramphenicol, gentamicin, enrofloxacin, erythromycin, and ticarcillin. No phenotypically vancomycin-resistant E. faecalis isolates were recovered from any of the raptors; three isolates had intermediate level susceptibility. A significantly higher number of isolates collected from captive birds demonstrated resistance to chloramphenicol than those obtained from free-living birds. This trend was not duplicated with any of the remaining

  20. Characterization of Enterococcus spp. from human and animal feces using 16S rRNA sequences, the esp gene, and PFGE for microbial source tracking in Korea.

    PubMed

    Kim, Sei-Yoon; Lee, Jung Eun; Lee, Sunghee; Lee, Hee Tae; Hur, Ho-Gil; Ko, Gwangpyo

    2010-05-01

    Contamination from human and animal fecal waste is a primary cause of water pollution. Microbial source tracking (MST) may be a useful tool for high-quality environmental management and for assessing human health risks associated with water pollution. The goal of this study was to evaluate Enterococcus spp. as a target organism for MST. Thirty-four fecal samples were collected from five different sources (human, chicken, pig, cow, and goose) in South Korea. In total, 237 Enterococcus spp. were isolated from feces using membrane- Enterococcus indoxyl-beta-d-glucoside agar. The 16S rRNA gene and the whole genome were analyzed using nucleic acid sequencing and pulsed-field gel electrophoresis (PFGE), respectively. Both phylogenetic analysis and principal coordinate analysis using UniFrac were performed on the nucleic acid sequences of the 16S rRNA gene. According to P-tests from UniFrac, significant differences existed between Enterococcus spp. isolated from human feces and those from animal feces. In addition, we evaluated whether the esp gene of Enterococcus faecium could be a specific target for Enterococcus spp. isolated from human feces. Of 58 E. faecium isolates tested, only three were esp-positive. The specificity of the esp gene of E. faecium isolated from human feces was 100%, but the sensitivity was <10%. These results suggest that Enterococcus spp. have different molecular characteristics according to their fecal source and that these characteristics can be further identified by analyzing the esp gene and 16S rRNA sequences, whereas PFGE provides limited information on the fecal sources of Enterococcus spp.

  1. Insertions of IS256-like element flanking the chromosomal beta-lactamase gene of Enterococcus faecalis CX19.

    PubMed Central

    Rice, L B; Marshall, S H

    1994-01-01

    We have previously identified an inverted repeat characteristic of staphylococcal beta-lactamase transposons adjacent to the chromosomal beta-lactamase genes of Enterococcus faecalis CH19 and its beta-lactamase-producing transconjugant CX19. Nucleotide sequence analysis of the CH19 beta-lactamase structural gene (blaZ) reveals it to be identical to the blaZ gene from E. faecalis HH22 and to the blaZ gene from the staphylococcal beta-lactamase transposon Tn552. We also report the presence of nucleotide sequence identical to a 317-bp region of the staphylococcal insertion sequence IS256 upstream of the blaZ gene in both CH19 and CX19. The identical segment of IS256 is present downstream of the blaZ gene of CX19, suggesting a second insertion of the element (in the inverted orientation) accompanying transfer to the recipient strain. Restriction analysis of the areas beyond the ClaI sites used to clone these regions suggests that full copies of the IS256-like element (designated IS256E) are present in all positions but that these elements were not directly involved in the transfer of the beta-lactamase gene to the recipient strain. We have also identified a region downstream of the second IS256E insertion site which exhibits substantial homology to ISSIW, an iso-ISSI insertion originally identified in Lactococcus lactis subsp. cremoris. These data suggest that the two enterococcal blaZ genes sequenced to date evolved from a common ancestor and may at one time have been incorporated into a transposon similar to Tn552. They also suggest that IS256-like elements are mobile in E. faecalis and capable of inserting in a manner consistent with the formation of novel composite transposons. Finally, they provide the first confirmation of the presence of an ISSI-like element in enterococci, raising the possibility that these elements play a role in the exchange of chromosomal antimicrobial resistance determinants. Images PMID:8031032

  2. Partial Diversity Generates Effector Immunity Specificity of the Bac41-Like Bacteriocins of Enterococcus faecalis Clinical Strains

    PubMed Central

    Kurushima, Jun; Ike, Yasuyoshi

    2016-01-01

    ABSTRACT Bacteriocin 41 (Bac41) is the plasmid-encoded bacteriocin produced by the opportunistic pathogen Enterococcus faecalis. Its genetic determinant consists of bacL1 (effector), bacL2 (regulator), bacA (effector), and bacI (immunity). The secreted effectors BacL1 and BacA coordinate to induce the lytic cell death of E. faecalis. Meanwhile, the immunity factor BacI provides self-resistance to the Bac41 producer, E. faecalis, against the action of BacL1 and BacA. In this study, we demonstrated that more than half of the 327 clinical strains of E. faecalis screened had functional Bac41 genes. Analysis of the genetic structure of the Bac41 genes in the DNA sequences of the E. faecalis strains revealed that the Bac41-like genes consist of a relatively conserved region and a variable region located downstream from bacA. Based on similarities in the variable region, the Bac41-like genes could be classified into type I, type IIa, and type IIb. Interestingly, the distinct Bac41 types had specific immunity factors for self-resistance, BacI1 or BacI2, and did not show cross-immunity to the other type of effector. We also demonstrated experimentally that the specificity of the immunity was determined by the combination of the C-terminal region of BacA and the presence of the unique BacI1 or BacI2 factor. These observations suggested that Bac41-like bacteriocin genes are extensively disseminated among E. faecalis strains in the clinical environment and can be grouped into at least three types. It was also indicated that the partial diversity results in specificity of self-resistance which may offer these strains a competitive advantage. IMPORTANCE Bacteriocins are antibacterial effectors produced by bacteria. In general, a bacteriocin-coding gene is accompanied by a cognate immunity gene that confers self-resistance on the bacteriocin-producing bacterium itself. We demonstrated that one of the bacteriocins, Bac41, is disseminated among E. faecalis clinical strains and the

  3. Transcriptomic and metabolic responses of Staphylococcus aureus in mixed culture with Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans in milk.

    PubMed

    Zdenkova, Kamila; Alibayov, Babek; Karamonova, Ludmila; Purkrtova, Sabina; Karpiskova, Renata; Demnerova, Katerina

    2016-09-01

    Staphylococcus aureus is a major food-borne pathogen due to the production of enterotoxin and is particularly prevalent in contaminated milk and dairy products. The lactic acid bacteria (LAB) are widely used as biocontrol agents in fermented foods which can inhibit pathogenic flora. In our work, we investigated the influence of three strains of LAB (Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans) on the relative expression of three enterotoxin genes (sea, sec, sell) and eight virulence and/or regulatory genes (sarA, saeS, codY, srrA, rot, hld/RNAIII, agrA/RNAII, sigB) in two S. aureus strains (MW2 and Sa1612) in TSB and reduced-fat milk (1.5 %) at 30 °C over a 24-h period. The tested LAB and S. aureus strains proved to be mutually non-competitive or only slightly competitive during co-cultivation. In addition, under the above-mentioned conditions, differential gene expression between the S. aureus MW2 and Sa1612 strains was well documented. S. aureus growth was changed in mixed culture with LAB; however, its effect on the repression of sea and sec expression correlated with production of these virulence factors. In comparison, the presence of LAB strains generally inhibited the expression of sec, sell, sarA, seaS, agrA/RNAII and hld/RNAIII genes. The effect of LAB strains presence on the expression of sea, codY, srrA, rot and sigB genes was medium, time, LAB and S. aureus strain specific. SEA and SEC production was significantly reduced in milk compared to TSB in pure culture. After the 24-h cultivation, S. aureus MW2 and Sa1612 SEC production was 187 and 331 times lower in milk compared to TSB, respectively (0.07 and 0.39 ng/mL in milk, versus 13.1 and 129.2 ng/mL in TSB, respectively). At the same time S. aureus MW2 and Sa1612 SEA production was 77 and 68 times lower in milk compared to TSB, respectively (0.99 and 0.17 ng/mL in milk, versus 76.4 and 11.5 ng/mL in TSB, respectively). This study has revealed new insights into the

  4. The tyrosyl-tRNA synthetase like gene located in the tyramine biosynthesis cluster of Enterococcus durans is transcriptionally regulated by tyrosine concentration and extracellular pH

    PubMed Central

    2012-01-01

    Background The tyramine producer Enterococcus durans IPLA655 contains all the necessary genes for tyramine biosynthesis, grouped in the TDC cluster. This cluster includes tyrS, an aminoacyl-tRNA synthetase like gene. Results This work shows that tyrS was maximally transcribed in absence of tyrosine at acidic pH, showing a greater than 10-fold induction in mRNA levels over levels occurring in presence of tyrosine. Mapping of the tyrS transcriptional start site revealed an unusually long untranslated leader region of 322 bp, which displays the typical features of the T box transcriptional attenuation mechanism. The tyrosine concentration regulation of tyrS was found to be mediated by a transcription antitermination system, whereas the specific induction at acidic pH was regulated at transcription initiation level. Conclusions The expression of the tyrS gene present in the TDC cluster of E. durans is transcriptionally regulated by tyrosine concentration and extracelular pH. The regulation is mediated by both an antitermination system and the promoter itself. PMID:22333391

  5. Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil.

    PubMed

    Infante, Victor Hugo Pacagnelli; Conceição, Natália; de Oliveira, Adriana Gonçalves; Darini, Ana Lúcia da Costa

    2016-04-01

    The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other β-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance.

  6. Effects of two novel amino acid substitutions on the penicillin binding properties of the PBP5 C‑terminal from Enterococcus faecium.

    PubMed

    Zhou, Chengjiang; Niu, Haiying; Yu, Hui; Zhou, Lishe; Wang, Zhanli

    2015-10-01

    The low‑affinity penicillin‑binding protein (PBP)5 is responsible for resistance to β‑lactam antibiotics in Enterococcus faecium. (E. faecium). In order to evaluate more fully the potential of this species for the development of resistance to β-lactam antibiotics, the present study aimed to examine the extent of penicillin-binding protein (PBP) variations in a collection of clinical E. faecium isolates. In the present study, the C‑terminal domain of PBP5 (PBP5‑CD) of 13 penicillin‑resistant clinical isolates of E. faecium were sequenced and the correlation between penicillin resistance and particular amino acid changes were analyzed. The present study identified for the first time, to the best of our knowledge, two novel substitutions (Tyr460Phe and Ala462Thr or Val462Thr) of E. faecium PBP5‑CD. The covalent interaction between penicillin and PBP5‑CD was also investigated using homology modeling and molecular docking methods. The theoretical calculation revealed that Phe460 and Thr462 were involved in penicillin binding, suggesting that substitutions at these positions exert effects on the affinity for penicillin, and this increased affinity translates into lower resistance in vitro.

  7. Biofilm forming capacity of Enterococcus faecalis on Gutta-percha points treated with four disinfectants using confocal scanning laser microscope: An in vitro study

    PubMed Central

    Ravi Chandra, Polavarapu Venkata; Kumar, Vemisetty Hari; Reddy, Surakanti Jayaprada; Kiran, Dandolu Ram; Krishna, Muppala Nagendra; Kumar, Golla Vinay

    2015-01-01

    Background: The aim of this study was to evaluate and compare the in vitro biofilm forming capacity of Enterococcus faecalis on Gutta-percha points disinfected with four disinfectants. Materials and Methods: A total of 50 Gutta-percha points used in this study were divided into four test groups based on disinfectant (5.25% sodium hypochlorite, 2% chlorhexidine gluconate, 20% neem, 13% benzalkonium chloride [BAK]), and one control group. The Gutta-percha points were initially treated with corresponding disinfectants followed by anaerobic incubation in Brain Heart Infusion broth suspended with human serum and E. faecalis strain for 14 days. After incubation, these Gutta-percha points were stained with Acridine Orange (Sigma – Aldrich Co., St. Louis, MO, USA) and 0.5 mm thick cross section samples were prepared. The biofilm thickness of E. faecalis was analyzed quantitatively using a confocal scanning laser microscope. Results statistically analyzed using analysis of variance. P < 0.05 was considered to be significant. Results: Confocal scanning laser microscope showed reduced amount of E. faecalis biofilm on Gutta-percha points treated with BAK and sodium hypochlorite. Post-hoc (least square differences) test revealed that there is no statistically significant difference between BAK and sodium hypochlorite groups (P > 0.05). Conclusion: This study illustrates that the Gutta-percha points disinfected with sodium hypochlorite and BAK showed minimal biofilm growth on its surface. PMID:26288622

  8. Synthesis and Evaluation of 1,2,4-Triazolo[1,5-a]pyrimidines as Antibacterial Agents Against Enterococcus faecium

    PubMed Central

    Wang, Huan; Lee, Mijoon; Peng, Zhihong; Blázquez, Blas; Lastochkin, Elena; Kumarasiri, Malika; Bouley, Renee; Chang, Mayland; Mobashery, Shahriar

    2015-01-01

    Rapid emergence of antibiotic resistance is one of the most challenging global public health concerns. In particular, vancomycin-resistant Enterococcus faecium infections have been increasing in frequency, representing 25% of enterococci infections in intensive care units. A novel class of 1,2,4-triazolo[1,5-a]pyrimidines active against E. faecium is reported herein. We used a three-component Biginelli-like heterocyclization reaction for the synthesis of a series of these derivatives based on reactions of aldehydes, β-dicarbonyl compounds, and 3-alkylthio-5-amino-1,2,4-tria-zoles. The resulting compounds were assayed for antimicrobial activity against the ESKAPE panel of bacteria, followed by investigation of their in vitro activities. These analyses identified a subset of 1,2,4-triazolo[1,5-a]pyrimidines that had good narrow-spectrum antibacterial activity against E. faecium and exhibited metabolic stability with low intrinsic clearance. Macromolecular synthesis assays revealed cell-wall biosynthesis as the target of these antibiotics. PMID:25923368

  9. Mass transfer characterization of gamma-aminobutyric acid production by Enterococcus faecium CFR 3003: encapsulation improves its survival under simulated gastro-intestinal conditions.

    PubMed

    Divyashri, Gangaraju; Prapulla, Siddalingaiya Gurudatt

    2015-03-01

    Gamma-aminobutyric acid (GABA) production by free and Ca-alginate encapsulated cells of Enterococcus faecium CFR 3003 was investigated. Mass transfer rates characterizing the GABA production process using encapsulated cells were investigated. Experiments were performed to investigate external film and internal pore diffusion mass transfer rates. The Damkohler and Thiele analysis provides a good description of external film and internal pore diffusion resistances, respectively. The experiments revealed that the external film effects could be neglected but the process is affected to the greater extent by internal mass transfer effects and was found to be the principal rate-controlling step. Protective effect of encapsulation on cell survivability was tested under digestive environment, when challenged to salivary α-amylase, simulated gastric fluid and intestinal fluid. Viability of encapsulated cells was significantly higher under simulated gastro-intestinal conditions and could produce higher GABA than those observed with free cells. The results indicate that the Ca-alginate encapsulated probiotics could effectively be delivered to the colonic site for effective inhibitory action.

  10. Probiotic Enterococcus faecalis Symbioflor(®) down regulates virulence genes of EHEC in vitro and decrease pathogenicity in a Caenorhabditis elegans model.

    PubMed

    Neuhaus, Klaus; Lamparter, Marina C; Zölch, Benjamin; Landstorfer, Richard; Simon, Svenja; Spanier, Britta; Ehrmann, Matthias A; Vogel, Rudi F

    2017-03-01

    Enterohemorrhagic E. coli O157:H7 (EHEC) shorten the lifespan of Caenorhabditis elegans compared to avirulent bacteria. Co-feeding EHEC with Enterococcus faecalis Symbioflor(®) significantly increased the worms' lifespan. The transcriptome of EHEC grown in vitro with or without Symbioflor(®) was analyzed using RNA-seq. The analysis revealed downregulation of several virulence-associated genes in the presence of Symbioflor(®), including virulence key genes (e.g., LEE, flagellum, quorum-sensing). The downregulation of the LEE genes was corroborated by lux-transposon mutants. Upregulated genes included acid response genes, due to a decrease in pH exerted by Symbioflor(®). Further genes indicate cellular stress in EHEC (e.g. prophage/mobile elements involved in excision, cell lysis, and cell division inhibition). Thus, the observed protection of C. elegans during an EHEC infection by the probiotic Symbioflor(®) is suggested to be caused by triggering concomitant transcriptomic changes. To verify the biological relevance of this modulation, exemplary genes found to be influenced by Symbioflor(®) were knocked out (fliD, espB, Z3136, Z3917, and L7052). The lifespan of nematodes changed when using knock-outs as food source and the effect could be complemented in trans. In summary, Symbioflor(®) appears to be a protective probiotic in the nematode model.

  11. Effects of the Enterococcus faecalis hypR gene encoding a new transcriptional regulator on oxidative stress response and intracellular survival within macrophages.

    PubMed

    Verneuil, Nicolas; Sanguinetti, Maurizio; Le Breton, Yoann; Posteraro, Brunella; Fadda, Giovanni; Auffray, Yanick; Hartke, Axel; Giard, Jean-Christophe

    2004-08-01

    In order to identify regulators of the oxidative stress response in Enterococcus faecalis, an important human pathogen, several genes annotated as coding for transcriptional regulators were inactivated by insertional mutagenesis. One mutant, affected in the ef2958 locus (designated hypR [hydrogen peroxide regulator]), appeared to be highly sensitive to oxidative challenge caused by hydrogen peroxide. Moreover, testing of the hypR mutant by using an in vivo-in vitro macrophage infection model resulted in a highly significant reduction in survival compared to the survival of parent strain JH2-2. Northern blot analyses were carried out with probes specific for genes encoding known antioxidant enzymes, and they showed that the ahpCF (alkyl hydroperoxide reductase) transcript was expressed less in mutant cells. Mobility shift protein-DNA binding assays revealed that HypR regulated directly the expression of hypR itself and the ahpCF operon. Our combined results showed that HypR appeared to be directly involved in the expression of ahpCF genes under oxidative stress conditions and suggested that this regulator could contribute to the virulence of E. faecalis.

  12. CspR, a Cold Shock RNA-Binding Protein Involved in the Long-Term Survival and the Virulence of Enterococcus faecalis

    PubMed Central

    Michaux, Charlotte; Martini, Cecilia; Shioya, Koki; Ahmed Lecheheb, Sandra; Budin-Verneuil, Aurélie; Cosette, Pascal; Sanguinetti, Maurizio; Hartke, Axel; Verneuil, Nicolas

    2012-01-01

    By coprecipitation, we identified RNA-binding proteins in the Gram-positive opportunistic pathogen Enterococcus faecalis known to be deficient of the RNA chaperone Hfq. In particular, we characterized one belonging to the cold shock protein (Csp) family (Ef2925) renamed CspR for cold shock protein RNA binding. Compared to the wild-type strain, the ΔcspR mutant was less virulent in an insect infection model (Galleria mellonella) and exhibited a decreased persistence in mouse kidneys and a low survival rate in peritoneal macrophages. As expected, we found that the ΔcspR mutant strain was more impaired in its growth than the parental strain under cold conditions and in its long-term survival under nutrient starvation. All these phenotypes were restored after complementation of the ΔcspR mutant. In addition, Western blot analysis showed that CspR was overexpressed under cold shock conditions and in the stationary phase. Since CspR may act as an RNA chaperone, putative targets were identified using a global proteomic approach completed with transcriptomic assays. This study revealed that 19 proteins were differentially expressed in the ΔcspR strain (9 upregulated, 10 downregulated) and that CspR mainly acted at the posttranscriptional level. These data highlight for the first time the role of the RNA-binding protein CspR as a regulator in E. faecalis and its requirement in stress response and virulence in this important human pathogen. PMID:23086208

  13. CspR, a cold shock RNA-binding protein involved in the long-term survival and the virulence of Enterococcus faecalis.

    PubMed

    Michaux, Charlotte; Martini, Cecilia; Shioya, Koki; Ahmed Lecheheb, Sandra; Budin-Verneuil, Aurélie; Cosette, Pascal; Sanguinetti, Maurizio; Hartke, Axel; Verneuil, Nicolas; Giard, Jean-Christophe

    2012-12-01

    By coprecipitation, we identified RNA-binding proteins in the Gram-positive opportunistic pathogen Enterococcus faecalis known to be deficient of the RNA chaperone Hfq. In particular, we characterized one belonging to the cold shock protein (Csp) family (Ef2925) renamed CspR for cold shock protein RNA binding. Compared to the wild-type strain, the ΔcspR mutant was less virulent in an insect infection model (Galleria mellonella) and exhibited a decreased persistence in mouse kidneys and a low survival rate in peritoneal macrophages. As expected, we found that the ΔcspR mutant strain was more impaired in its growth than the parental strain under cold conditions and in its long-term survival under nutrient starvation. All these phenotypes were restored after complementation of the ΔcspR mutant. In addition, Western blot analysis showed that CspR was overexpressed under cold shock conditions and in the stationary phase. Since CspR may act as an RNA chaperone, putative targets were identified using a global proteomic approach completed with transcriptomic assays. This study revealed that 19 proteins were differentially expressed in the ΔcspR strain (9 upregulated, 10 downregulated) and that CspR mainly acted at the posttranscriptional level. These data highlight for the first time the role of the RNA-binding protein CspR as a regulator in E. faecalis and its requirement in stress response and virulence in this important human pathogen.

  14. Clinical and molecular epidemiology of hospital Enterococcus faecium isolates in eastern France. Members of Réseau Franc-Comtois de Lutte contr les Infections Nosocomiales.

    PubMed

    Bertrand, X; Thouverez, M; Bailly, P; Cornette, C; Talon, D

    2000-06-01

    We carried out a surveillance study of Enterococcus faecium isolates in the Franche-Comtéregion of France over three years. Clinical and epidemiological strains were characterized by antibiotype and genotype (pulsed field gel electrophoresis, PFGE). Three case-control studies were performed to identify risk factors for colonization/infection with three defined resistant phenotypes (amoxycillin, high-level gentamicin and high-level kanamycin). The crude incidence of colonization/infection was 0.156%, and 68.8% of cases were classified as hospital-acquired. Incidence did not differ according to the type of hospitalization (middle term or acute care). The urinary tract was the major site of infection. Resistance rates were: 45.8% (amoxycillin), 18.7% (high-level gentamicin), 61.4% (high-level kanamycin) and 3.1% (vancomycin). No isolate produced b-lactamase and one isolate carried the vanA gene. PFGE revealed two major epidemic patterns each including resistant strains isolated in different hospitals and during different periods in the study. Previous antimicrobial treatment was not identified as a risk factor for colonization/infection with any resistant phenotype. Despite the low frequency of vancomycin-resistant isolates in this study, resistant strains were widely disseminated and had characteristics enabling them to persist and spread. If these strains acquired the vanA gene, the risk of an outbreak would be large. So, the prevalence of vancomycin-resistant E. faecium in hospitals should be carefully monitored in the future.

  15. Local Genetic Patterns within a Vancomycin-Resistant Enterococcus faecalis Clone Isolated in Three Hospitals in Portugal

    PubMed Central

    Novais, Carla; Coque, Teresa M.; Sousa, João Carlos; Baquero, Fernando; Peixe, Luisa

    2004-01-01

    Eight pulsed-field gel electrophoresis subtypes and six Tn1546 variants were identified among Enterococcus faecalis isolates of a single clone recovered in three geographically separate Portuguese hospitals. Some clonal subtypes were found in particular hospitals, and Tn1546 variants were either widespread or confined to some of them. We also report on the first Tn1546 transposon containing an ISEf1 insertion. PMID:15328141

  16. The In Vitro Contribution of Autolysins to Bacterial Killing Elicited by Amoxicillin Increases with Inoculum Size in Enterococcus faecalis▿ †

    PubMed Central

    Dubée, Vincent; Chau, Françoise; Arthur, Michel; Garry, Louis; Benadda, Samira; Mesnage, Stéphane; Lefort, Agnès; Fantin, Bruno

    2011-01-01

    The mechanisms of antibiotic-induced cell death are poorly understood despite the critical role of the bactericidal activities of antibiotics for successful treatment of severe infections. These mechanisms include irreversible damaging of macromolecules by reactive oxygen species and bacteriolysis mediated by peptidoglycan hydrolases (autolysins). We have assessed the contribution of the second mechanism by using an autolysin-deficient mutant of Enterococcus faecalis and shown that it contributes to amoxicillin-induced cell lysis only at a high bacterial density. PMID:21098238

  17. Critical Importance of In Vivo Amoxicillin and Cefotaxime Concentrations for Synergy in Treatment of Experimental Enterococcus faecalis Endocarditis

    PubMed Central

    Join-Lambert, Olivier; Mainardi, Jean-Luc; Cuvelier, Catherine; Dautrey, Sophie; Farinotti, Robert; Fantin, Bruno; Carbon, Claude

    1998-01-01

    The synergy between amoxicillin and cefotaxime against two strains of Enterococcus faecalis (JH2-2 and 6370) in vitro and in rabbit endocarditis was investigated. In vitro synergy was obtained only when amoxicillin concentrations were below the MBC and when cefotaxime concentrations were above 1 μg/ml. No synergy was observed in vivo, because of the short period of time during which these pharmacologic requirements were achieved. PMID:9527811

  18. Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study.

    PubMed

    Tornero, E; Senneville, E; Euba, G; Petersdorf, S; Rodriguez-Pardo, D; Lakatos, B; Ferrari, M C; Pilares, M; Bahamonde, A; Trebse, R; Benito, N; Sorli, L; del Toro, M D; Baraiaetxaburu, J M; Ramos, A; Riera, M; Jover-Sáenz, A; Palomino, J; Ariza, J; Soriano, A

    2014-11-01

    The objective of this study was to review the characteristics and outcome of prosthetic joint infections (PJI) due to Enterococcus sp. collected in 18 hospitals from six European countries. Patients with a PJI due to Enterococcus sp. diagnosed between January 1999 and July 2012 were retrospectively reviewed. Relevant information about demographics, comorbidity, clinical characteristics, microbiological data, surgical treatment and outcome was registered. Univariable and multivariable analyses were performed. A total of 203 patients met the inclusion criteria. The mean (SD) was 70.4 (13.6) years. In 59 patients the infection was diagnosed within the first 30 days (29.1%) from arthroplasty, in 44 (21.7%) between 31 and 90 days, in 54 (26.6%) between 91 days and 2 years and in 43 (21%) after 2 years. Enterococcus faecalis was isolated in 176 cases (89%). In 107 (54%) patients the infection was polymicrobial. Any comorbidity (OR 2.53, 95% CI 1.18-5.40, p 0.01), and fever (OR 2.65, 95% CI 1.23-5.69, p 0.01) were independently associated with failure. The only factor associated with remission was infections diagnosed later than 2 years (OR 0.25, 95% CI 0.09-0.71, p 0.009). In conclusion, prosthetic joint infections due to Enterococcus sp. were diagnosed within the first 2 years from arthroplasty in >70% of the patients, almost 50% had at least one comorbidity and infections were frequently polymicrobial (54%). The global failure rate was 44% and patients with comorbidities, fever, and diagnosed within the first 2 years from arthroplasty had a poor prognosis.

  19. Diversity and Evolution of the Tn5801-tet(M)-Like Integrative and Conjugative Elements among Enterococcus, Streptococcus, and Staphylococcus.

    PubMed

    León-Sampedro, Ricardo; Novais, Carla; Peixe, Luísa; Baquero, Fernando; Coque, Teresa M

    2016-01-04

    This work describes the diversity and evolution of Tn5801 among enterococci, staphylococci, and streptococci based on analysis of the 5,073 genomes of these bacterial groups available in gene databases. We also examined 610 isolates of Enterococcus (from 10 countries, 1987 to 2010) for the presence of this and other known CTn-tet(M) elements due to the scarcity of data about Tn5801 among enterococci. Genome location (by ICeu-I-pulsed-field gel electrophoresis [PFGE] hybridization/integration site identification), conjugation and fitness (by standard methods), Tn5801 characterization (by long-PCR mapping/sequencing), and clonality (by PFGE/multilocus sequence typing [MLST]) were studied. Twenty-three Tn5801 variants (17 unpublished) clustered in two groups, designated "A" (25 kb; n = 14; predominant in Staphylococcus aureus) and "B" (20 kb; n = 9; predominant in Streptococcus agalactiae). The percent GC content of the common backbone suggests a streptococcal origin of Tn5801 group B, with further acquisition of a 5-kb fragment that resulted in group A. Deep sequence analysis allowed identification of variants associated with clonal lineages of S. aureus (clonal complex 8 [CC8], sequence type 239 [ST239]), S. agalactiae (CC17), Enterococcus faecium (ST17/ST18), or Enterococcus faecalis (ST8), local variants, or variants located in different species and geographical areas. All Tn5801 elements were chromosomally located upstream of the guaA gene, which serves as an integration hot spot. Transferability was demonstrated only for Tn5801 type B among E. faecalis clonal backgrounds, which eventually harbored another Tn5801 copy. The study documents early acquisition of Tn5801 by Enterococcus, Staphylococcus, and Streptococcus. Clonal waves of these pathogens seem to have contributed to the geographical spread and local evolution of the transposon. Horizontal transfer, also demonstrated, could explain the variability observed, with the isolates often containing sequences of

  20. Dispersion of Multidrug-Resistant Enterococcus faecium Isolates Belonging to Major Clonal Complexes in Different Portuguese Settings▿

    PubMed Central

    Freitas, Ana R.; Novais, Carla; Ruiz-Garbajosa, Patricia; Coque, Teresa M.; Peixe, Luísa

    2009-01-01

    The population structure of 56 Enterococcus faecium isolates selected from a collection of enterococci from humans, animals, and the environment in Portugal (1997 to 2007) was analyzed by multilocus sequence typing. We identified 41 sequence types clustering into CC17, CC5, CC9, CC22 and CC94, all clonal lineages comprising isolates from different hosts. Our findings highlight the role of community-associated hosts as reservoirs of enterococci able to cause human infections. PMID:19447948

  1. Diversity and Evolution of the Tn5801-tet(M)-Like Integrative and Conjugative Elements among Enterococcus, Streptococcus, and Staphylococcus

    PubMed Central

    León-Sampedro, Ricardo; Novais, Carla; Peixe, Luísa; Baquero, Fernando

    2016-01-01

    This work describes the diversity and evolution of Tn5801 among enterococci, staphylococci, and streptococci based on analysis of the 5,073 genomes of these bacterial groups available in gene databases. We also examined 610 isolates of Enterococcus (from 10 countries, 1987 to 2010) for the presence of this and other known CTn-tet(M) elements due to the scarcity of data about Tn5801 among enterococci. Genome location (by ICeu-I–pulsed-field gel electrophoresis [PFGE] hybridization/integration site identification), conjugation and fitness (by standard methods), Tn5801 characterization (by long-PCR mapping/sequencing), and clonality (by PFGE/multilocus sequence typing [MLST]) were studied. Twenty-three Tn5801 variants (17 unpublished) clustered in two groups, designated “A” (25 kb; n = 14; predominant in Staphylococcus aureus) and “B” (20 kb; n = 9; predominant in Streptococcus agalactiae). The percent GC content of the common backbone suggests a streptococcal origin of Tn5801 group B, with further acquisition of a 5-kb fragment that resulted in group A. Deep sequence analysis allowed identification of variants associated with clonal lineages of S. aureus (clonal complex 8 [CC8], sequence type 239 [ST239]), S. agalactiae (CC17), Enterococcus faecium (ST17/ST18), or Enterococcus faecalis (ST8), local variants, or variants located in different species and geographical areas. All Tn5801 elements were chromosomally located upstream of the guaA gene, which serves as an integration hot spot. Transferability was demonstrated only for Tn5801 type B among E. faecalis clonal backgrounds, which eventually harbored another Tn5801 copy. The study documents early acquisition of Tn5801 by Enterococcus, Staphylococcus, and Streptococcus. Clonal waves of these pathogens seem to have contributed to the geographical spread and local evolution of the transposon. Horizontal transfer, also demonstrated, could explain the variability observed, with the isolates often containing

  2. Production of Enterocin P, an Antilisterial Pediocin-Like Bacteriocin from Enterococcus faecium P13, in Pichia pastoris

    PubMed Central

    Gutiérrez, Jorge; Criado, Raquel; Martín, María; Herranz, Carmen; Cintas, Luis M.; Hernández, Pablo E.

    2005-01-01

    The gene encoding mature enterocin P (EntP), an antimicrobial peptide from Enterococcus faecium P13, was cloned into the pPICZαA expression vector to generate plasmid pJC31. This plasmid was integrated into the genome of P. pastoris X-33, and EntP was heterologously secreted from the recombinant P. pastoris X-33t1 derivative at a higher production and antagonistic activity than from E. faecium P13. PMID:15980385

  3. Culture methods impact recovery of antibiotic-resistant Enterococci including Enterococcus cecorum from pre- and postharvest chicken.

    PubMed

    Suyemoto, M M; Barnes, H J; Borst, L B

    2017-03-01

    Pathogenic strains of Enterococcus cecorum (EC) expressing multidrug resistance have emerged. In National Antimicrobial Resistance Monitoring System (NARMS) data, EC is rarely recovered from chickens. Two NARMS methodologies (FDA and USDA) were compared with standard culture (SC) techniques for recovery of EC. NARMS methods failed to detect EC in 58 caecal samples, 20 chicken breast or six whole broiler samples. EC was recovered from 1 of 38 (2·6%) and 2 of 38 (5·2%) preharvest spinal lesions (USDA and FDA method, respectively). In contrast, using the SC method, EC was recovered from 44 of 53 (83%) caecal samples, all 38 (100%) spinal lesions, 14 of 20 (70%) chicken breast samples, and all three spinal lesions identified in whole carcasses. Compared with other Enterococcus spp., EC isolates had a higher prevalence of resistance to macrolides. The NARMS methods significantly affected recovery of enterococcal species other than EC. When the postharvest FDA method was applied to preharvest caecal samples, isolates of Enterococcus faecium were preferentially recovered. All 11 E. faecium isolates were multidrug resistant, including resistance to penicillin, daptomycin and linezolid. These findings confirm that current methodologies may not accurately identify the amount and range of antimicrobial resistance of enterococci from chicken sources.

  4. Role of Combination Antimicrobial Therapy for Vancomycin-Resistant Enterococcus faecium Infections: Review of the Current Evidence.

    PubMed

    Yim, Juwon; Smith, Jordan R; Rybak, Michael J

    2017-03-08

    Enterococcus species are the second most common cause of nosocomial infections in the United States and are particularly concerning in critically ill patients with preexisting comorbid conditions. Rising resistance to antimicrobials that were historically used as front-line agents for treatment of enterococcal infections, such as ampicillin, vancomycin, and aminoglycosides, further complicates the treatment of these infections. Of particular concern are Enterococcus faecium strains that are associated with the highest rate of vancomycin resistance. The introduction of antimicrobial agents with specific activity against vancomycin-resistant Enterococcus (VRE) faecium including daptomycin, linezolid, quinupristin-dalfopristin, and tigecycline did not completely resolve this clinical dilemma. In this review, the mechanisms of action and resistance to currently available anti-VRE antimicrobial agents including newer agents such as oritavancin and dalbavancin will be presented. In addition, novel combination therapies including β-lactams and fosfomycin, and the promising results from in vitro, animal studies, and clinical experience in the treatment of VRE faecium will be discussed. This article is protected by copyright. All rights reserved.

  5. Comparative Genomics of cpn60-Defined Enterococcus hirae Ecotypes and Relationship of Gene Content Differences to Competitive Fitness.

    PubMed

    Katyal, Isha; Chaban, Bonnie; Hill, Janet E

    2016-11-01

    Natural microbial communities undergo selection-driven succession with changes in environmental conditions and available nutrients. In a previous study of the pig faecal Enterococcus community, we demonstrated that cpn60 universal target (UT) sequences could resolve phenotypically and genotypically distinct ecotypes of Enterococcus spp. that emerged over time in the faecal microbiome of growing pigs. In this study, we characterized genomic diversity in the identified Enterococcus hirae ecotypes in order to define further the nature and degree of genome content differences between taxa resolved by cpn60 UT sequences. Genome sequences for six representative isolates (two from each of three ecotypes) were compared. Differences in phosphotransferase systems and amino acid metabolism pathways for glutamine, proline and selenocysteine were observed. Differences in the lac family phosphotransferase system corresponded to lactose utilization phenotypes of the isolates. Competitive fitness of the E. hirae ecotypes was evaluated by in vitro growth competition assays in pig faecal extract medium. Isolates from E. hirae-1 and E. hirae-2 ecotypes were able to out-compete isolates from the E. hirae-3 ecotype, consistent with the relatively low abundance of E. hirae-3 relative to E. hirae-1 and E. hirae-2 previously observed in the pig faecal microbiome, and with observed differences between the ecotypes in gene content related to biosynthetic capacity. Results of this study provide a genomic basis for the definition of ecotypes within E. hirae and confirm the utility of the cpn60 UT sequence for high-resolution profiling of complex microbial communities.

  6. Effects of microgravity on the virulence of Listeria monocytogenes, Enterococcus faecalis, Candida albicans, and methicillin-resistant Staphylococcus aureus.

    PubMed

    Hammond, Timothy G; Stodieck, Louis; Birdsall, Holly H; Becker, Jeanne L; Koenig, Paul; Hammond, Jeffrey S; Gunter, Margaret A; Allen, Patricia L

    2013-11-01

    To evaluate effects of microgravity on virulence, we studied the ability of four common clinical pathogens--Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, and Candida albicans--to kill wild type Caenorhabditis elegans (C. elegans) nematodes at the larval and adult stages. Simultaneous studies were performed utilizing spaceflight, clinorotation in a 2-D clinorotation device, and static ground controls. The feeding rate of worms for killed E. coli was unaffected by spaceflight or clinorotation. Nematodes, microbes, and growth media were separated until exposed to true or modeled microgravity, then mixed and grown for 48 h. Experiments were terminated by paraformaldehyde fixation, and optical density measurements were used to assay residual microorganisms. Spaceflight was associated with reduced virulence for Listeria, Enterococcus, MRSA, and Candida for both larval and adult C. elegans. These are the first data acquired with a direct in vivo assay system in space to demonstrate virulence. Clinorotation reproduced the effects of spaceflight in some, but not all, virulence assays: Candida and Enterococcus were less virulent for larval worms but not adult worms, whereas virulence of MRSA and Listeria were unaffected by clinorotation in tests with both adult and larval worms. We conclude that four common clinical microorganisms are all less virulent in space.

  7. Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An In Vitro Study.

    PubMed

    Dumani, Aysin; Guvenmez, Hatice Korkmaz; Yilmaz, Sehnaz; Yoldas, Oguz; Kurklu, Zeliha Gonca Bek

    2016-01-01

    Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl)2; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl)2 with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p < 0.05). There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl)2 and NaOCl. Conclusion. The antimicrobial property of Ca(OCl)2 has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth.

  8. Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An In Vitro Study

    PubMed Central

    Dumani, Aysin; Guvenmez, Hatice Korkmaz; Yilmaz, Sehnaz; Yoldas, Oguz; Kurklu, Zeliha Gonca Bek

    2016-01-01

    Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl)2; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl)2 with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p < 0.05). There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl)2 and NaOCl. Conclusion. The antimicrobial property of Ca(OCl)2 has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth. PMID:27218106

  9. Assessment of virulence factors, antibiotic resistance and amino-decarboxylase activity in Enterococcus faecium MXVK29 isolated from Mexican chorizo.

    PubMed

    Alvarez-Cisneros, Y M; Fernández, F J; Sainz-Espuñez, T; Ponce-Alquicira, E

    2017-02-01

    Enterococcus faecium MXVK29 has the ability to produce an antimicrobial compound that belongs to Class IIa of the Klaenhammer classification, and could be used as part of a biopreservation technology through direct inoculation of the strain as a starter or protective culture. However, Enterococcus is considered as an opportunistic pathogen, hence, the purpose of this work was to study the food safety determinants of E. faecium MXVK29. The strain was sensitive to all of the antibiotics tested (penicillin, tetracycline, vancomycin, erythromycin, chloramphenicol, gentamicin, neomycin, kanamycin and netilmicin) and did not demonstrate histamine, cadaverine or putrescine formation. Furthermore, tyrosine-decarboxylase activity was detected by qualitative assays and PCR. Among the virulence factors analysed for the strain, only the genes encoding the sexual pheromone cCF10 precursor lipoprotein (ccf) and cell-wall adhesion (efaAfm ) were amplified. The presence of these genes has low impact on pathogenesis, as there are no other genes encoding for virulence factors, such as aggregation proteins. Therefore, Enterococcus faecium could be employed as part of a bioconservation method, because it does not produce risk factors for consumer's health; in addition, it could be used as part of the hurdle technology in foods.

  10. Enterococcus faecium isolated from Lombo, a Portuguese traditional meat product: characterisation of antibacterial compounds and factors affecting bacteriocin production.

    PubMed

    Todorov, S D; Favaro, L; Gibbs, P; Vaz-Velho, M

    2012-12-01

    Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.

  11. Expression of Alzheimer-Type Neurofibrillary Epitopes in Primary Rat Cortical Neurons Following Infection with Enterococcus faecalis

    PubMed Central

    Underly, Robert; Song, Mee-Sook; Dunbar, Gary L.; Weaver, Charles L.

    2016-01-01

    The neurofibrillary tau pathology and amyloid deposits seen in Alzheimer’s disease (AD) also have been seen in bacteria-infected brains. However, few studies have examined the role of these bacteria in the generation of tau pathology. One suggested link between infection and AD is edentulism, the complete loss of teeth. Edentulism can result from chronic periodontal disease due to infection by Enterococcus faecalis. The current study assessed the ability to generate early Alzheimer-like neurofibrillary epitopes in primary rat cortical neurons through bacterial infection by E. faecalis. Seven-day old cultured neurons were infected with E. faecalis for 24 and 48 h. An upward molecular weight shift in tau by Western blotting (WB) and increased appearance of tau reactivity in cell bodies and degenerating neurites was found in the 48 h infection group for the antibody CP13 (phospho-Serine 202). A substantial increase in reactivity of Alz-50 was seen at 24 and 48 h after infection. Furthermore, extensive microtubule-associated protein 2 (MAP2) reactivity also was seen at 24 and 48 h post-infection. Our preliminary findings suggest a potential link between E. faecalis infection and intracellular changes that may help facilitate early AD-like neurofibrillary pathology. HighlightsEnterococcus faecalis used in the generation of AD neurofibrillary epitopes in rat.Infection increases Alz-50, phospho-Serine 202 tau, and MAP2 expression.Infection by Enterococcus may play a role in early Alzheimer neurofibrillary changes. PMID:26834627

  12. Pheromone-responsive conjugative vancomycin resistance plasmids in Enterococcus faecalis isolates from humans and chicken feces.

    PubMed

    Lim, Suk-Kyung; Tanimoto, Koichi; Tomita, Haruyoshi; Ike, Yasuyoshi

    2006-10-01

    The drug resistances and plasmid contents of a total of 85 vancomycin-resistant enterococcus (VRE) strains that had been isolated in Korea were examined. Fifty-four of the strains originated from samples of chicken feces, and 31 were isolated from hospital patients in Korea. Enterococcus faecalis KV1 and KV2, which had been isolated from a patient and a sample of chicken feces, respectively, were found to carry the plasmids pSL1 and pSL2, respectively. The plasmids transferred resistances to vancomycin, gentamicin, kanamycin, streptomycin, and erythromycin to E. faecalis strains at a high frequency of about 10(-3) per donor cell during 4 hours of broth mating. E. faecalis strains containing each of the pSL plasmids formed clumps after 2 hours of incubation in broth containing E. faecalis FA2-2 culture filtrate (i.e., the E. faecalis sex pheromone), and the plasmid subsequently transferred to the recipient strain in a 10-min short mating in broth, indicating that the plasmids are responsive to E. faecalis pheromones. The pSL plasmids did not respond to any of synthetic pheromones for the previously characterized plasmids. The pheromone specific for pSL plasmids has been designated cSL1. Southern hybridization analysis showed that specific FspI fragments from each of the pSL plasmids hybridized with the aggregation substance gene (asa1) of the pheromone-responsive plasmid pAD1, indicating that the plasmids had a gene homologous to asa1. The restriction maps of the plasmids were identical, and the size of the plasmids was estimated to be 128.1 kb. The plasmids carried five drug resistance determinants for vanA, ermB, aph(3'), aph(6'), and aac(6')/aph(2'), which encode resistance to vancomycin, erythromycin, kanamycin, streptomycin, and gentamicin/kanamycin, respectively. Nucleotide sequence analyses of the drug resistance determinants and their flanking regions are described in this report. The results described provide evidence for the exchange of genetic information

  13. A novel method for simultaneous Enterococcus species identification/typing and van genotyping by high resolution melt analysis.

    PubMed

    Gurtler, Volker; Grando, Danilla; Mayall, Barrie C; Wang, Jenny; Ghaly-Derias, Shahbano

    2012-09-01

    In order to develop a typing and identification method for van gene containing Enterococcus faecium, two multiplex PCR reactions were developed for use in HRM-PCR (High Resolution Melt-PCR): (i) vanA, vanB, vanC, vanC23 to detect van genes from different Enterococcus species; (ii) ISR (intergenic spacer region between the 16S and 23S rRNA genes) to detect all Enterococcus species and obtain species and isolate specific HRM curves. To test and validate the method three groups of isolates were tested: (i) 1672 Enterococcus species isolates from January 2009 to December 2009; (ii) 71 isolates previously identified and typed by PFGE (pulsed-field gel electrophoresis) and MLST (multi-locus sequence typing); and (iii) 18 of the isolates from (i) for which ISR sequencing was done. As well as successfully identifying 2 common genotypes by HRM from the Austin Hospital clinical isolates, this study analysed the sequences of all the vanB genes deposited in GenBank and developed a numerical classification scheme for the standardised naming of these vanB genotypes. The identification of Enterococcus faecalis from E. faecium was reliable and stable using ISR PCR. The typing of E. faecium by ISR PCR: (i) detected two variable peaks corresponding to different copy numbers of insertion sequences I and II corresponding to peak I and II respectively; (ii) produced 7 melt profiles for E. faecium with variable copy numbers of sequences I and II; (iii) demonstrated stability and instability of peak heights with equal frequency within the patient sample (36.4±4.5 days and 38.6±5.8 days respectively for 192 patients); (iv) detected ISR-HRM types with as much discrimination as PFGE and more than MLST; and (v) detected ISR-HRM types that differentiated some isolates that were identical by PFGE and MLST. In conjunction with the rapid and accurate van genotyping method described here, this ISR-HRM typing and identification method can be used as a stable identification and typing method with

  14. Escherichia coli and Enterococcus spp. in rainwater tank samples: comparison of culture-based methods and 23S rRNA gene quantitative PCR assays.

    PubMed

    Ahmed, W; Richardson, K; Sidhu, J P S; Toze, S

    2012-10-16

    In this study, culture-based methods and quantitative PCR (qPCR) assays were compared with each other for the measurement of Escherichia coli and Enterococcus spp. in water samples collected from rainwater tanks in Southeast Queensland, Australia. Among the 50 rainwater tank samples tested, 26 (52%) and 46 (92%) samples yielded E. coli numbers as measured by EPA Method 1603 and E. coli 23S rRNA gene qPCR assay, respectively. Similarly, 49 (98%) and 47 (94%) samples yielded Enterococcus spp. numbers as measured by EPA Method 1600 and Enterococcus spp. 23S rRNA gene qPCR assay, respectively. The mean E. coli (2.49 ± 0.85) log(10) and Enterococcus spp. (2.72 ± 0.32) log(10) numbers as measured by qPCR assays were significantly (P < 0001) different than E. coli (0.91 ± 0.80) log(10) and Enterococcus spp. (1.86 ± 0.60) log(10) numbers as measured by culture-based method. Weak but significant correlations were observed between both EPA Method 1603 and the E. coli qPCR assay (r = 0.47, P = 0.0009), and EPA Method 1600 and the Enterococcus spp. qPCR assay (r = 0.42, P = 0.002). Good qualitative agreement was found between the culture-based method and the Enterococcus spp. qPCR assay in terms of detecting fecal pollution in water samples from the studied rainwater tanks. More research studies, however, are needed to shed some light on the discrepancies associated with the culture-based methods and qPCR assays for measuring fecal indicator bacteria.

  15. The Presence and Origin of Enterococcus faecalis in Cabo Rojo, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Zachman, A. J.; Sturm, P.; Viqueira Ríos, R.

    2015-12-01

    Currently, a watershed management plan is being developed for Cabo Rojo region in Southwest Puerto Rico. This project fills in major gaps for water quality data on the Rio Viejo, a tributary on the Guanajibio River. The Rio Viejo flows through the town of Cabo Rojo, a town of 51,245 people. The project has identified 5 sites along the river to track bacterial loads. In the tropics, Enterococcus faecalis is an important indicator for fecal contamination in surface waters as it does not reproduce as quickly soils as E. coli. A combination of EPA 1600 and 9230B from Standard Methods for the Examination of Water and Wastewater for identification of E. faecalis were utilized. The assay is a four step procedure that identifies the four criteria of bacteria in the group D Streptococcus system. The criteria require that the bacteria are Gram-positive cocci and Esculin-positive. There also must be growth in Brain Heart Infusion Broth at 35C and 45C as well as growth in Brain Heart Infusion broth + 6.5% NaCl. Further research will be conducted at North Carolina State University to ascertain the vertebrate species that is the source of the contamination through the use of qPCR.

  16. The Intraperitoneal Transcriptome of the Opportunistic Pathogen Enterococcus faecalis in Mice

    PubMed Central

    Muller, Cécile; Cacaci, Margherita; Sauvageot, Nicolas; Sanguinetti, Maurizio; Rattei, Thomas; Eder, Thomas; Giard, Jean-Christophe; Kalinowski, Jörn; Hain, Torsten; Hartke, Axel

    2015-01-01

    Enterococcus faecalis is a Gram-positive lactic acid intestinal opportunistic bacterium with virulence potential. For a better understanding of the adapation of this bacterium to the host conditions, we performed a transcriptome analysis of bacteria isolated from an infection site (mouse peritonitis) by RNA-sequencing. We identified a total of 211 genes with significantly higher transcript levels and 157 repressed genes. Our in vivo gene expression database reflects well the infection process since genes encoding important virulence factors like cytolysin, gelatinase or aggregation substance as well as stress response proteins, are significantly induced. Genes encoding metabolic activities are the second most abundant in vivo induced genes demonstrating that the bacteria are metabolically active and adapt to the special nutrient conditions of the host. α- and β- glucosides seem to be important substrates for E. faecalis inside the host. Compared to laboratory conditions, the flux through the upper part of glycolysis seems to be reduced and more carbon may enter the pentose phosphate pathway. This may reflect the need of the bacteria under infection conditions to produce more reducing power for biosynthesis. Another important substrate is certainly glycerol since both pathways of glycerol catabolism are strongly induced. Strongly in vivo induced genes should be important for the infection process. This assumption has been verified in a virulence test using well characterized mutants affected in glycerol metabolism. This showed indeed that mutants unable to metabolize this sugar alcohol are affected in organ colonisation in a mouse model. PMID:25978463

  17. The Intraperitoneal Transcriptome of the Opportunistic Pathogen Enterococcus faecalis in Mice.

    PubMed

    Muller, Cécile; Cacaci, Margherita; Sauvageot, Nicolas; Sanguinetti, Maurizio; Rattei, Thomas; Eder, Thomas; Giard, Jean-Christophe; Kalinowski, Jörn; Hain, Torsten; Hartke, Axel

    2015-01-01

    Enterococcus faecalis is a Gram-positive lactic acid intestinal opportunistic bacterium with virulence potential. For a better understanding of the adapation of this bacterium to the host conditions, we performed a transcriptome analysis of bacteria isolated from an infection site (mouse peritonitis) by RNA-sequencing. We identified a total of 211 genes with significantly higher transcript levels and 157 repressed genes. Our in vivo gene expression database reflects well the infection process since genes encoding important virulence factors like cytolysin, gelatinase or aggregation substance as well as stress response proteins, are significantly induced. Genes encoding metabolic activities are the second most abundant in vivo induced genes demonstrating that the bacteria are metabolically active and adapt to the special nutrient conditions of the host. α- and β- glucosides seem to be important substrates for E. faecalis inside the host. Compared to laboratory conditions, the flux through the upper part of glycolysis seems to be reduced and more carbon may enter the pentose phosphate pathway. This may reflect the need of the bacteria under infection conditions to produce more reducing power for biosynthesis. Another important substrate is certainly glycerol since both pathways of glycerol catabolism are strongly induced. Strongly in vivo induced genes should be important for the infection process. This assumption has been verified in a virulence test using well characterized mutants affected in glycerol metabolism. This showed indeed that mutants unable to metabolize this sugar alcohol are affected in organ colonisation in a mouse model.

  18. Multiple-Antibiotic Resistance of Enterococcus spp. Isolated from Commercial Poultry Production Environments

    PubMed Central

    Hayes, Joshua R.; English, Linda L.; Carr, Lewis E.; Wagner, David D.; Joseph, Sam W.

    2004-01-01

    The potential impact of food animals in the production environment on the bacterial population as a result of antimicrobial drug use for growth enhancement continues to be a cause for concern. Enterococci from 82 farms within a poultry production region on the eastern seaboard were isolated to establish a baseline of susceptibility profiles for a number of antimicrobials used in production as well as clinical environments. Of the 541 isolates recovered, Enterococcus faecalis (53%) and E. faecium (31%) were the predominant species, while multiresistant antimicrobial phenotypes were observed among all species. The prevalence of resistance among isolates of E. faecalis was comparatively higher among lincosamide, macrolide, and tetracycline antimicrobials, while isolates of E. faecium were observed to be more frequently resistant to fluoroquinolones and penicillins. Notably, 63% of the E. faecium isolates were resistant to the streptogramin quinupristin-dalfopristin, while high-level gentamicin resistance was observed only among the E. faecalis population, of which 7% of the isolates were resistant. The primary observations are that enterococci can be frequently isolated from the poultry production environment and can be multiresistant to antimicrobials used in human medicine. The high frequency with which resistant enterococci are isolated from this environment suggests that these organisms might be useful as sentinels to monitor the development of resistance resulting from the usage of antimicrobial agents in animal production. PMID:15466544

  19. Endophthalmitis Caused by Enterococcus faecalis: Clinical Features, Antibiotic Sensitivities, and Outcomes

    PubMed Central

    Kuriyan, Ajay E.; Sridhar, Jayanth; Flynn, Harry W.; Smiddy, William E.; Albini, Thomas A.; Berrocal, Audina M.; Forster, Richard K.; Belin, Peter J.; Miller, Darlene

    2014-01-01

    Purpose To report the clinical features, antibiotic sensitivities, and visual acuity (VA) outcomes of endophthalmitis caused by Enterococcus faecalis. Study Design Retrospective, observational case series. Methods A consecutive case series of patients with culture-positive endophthalmitis caused by E. faecalis between January 1, 2002 and December 31, 2012 at an academic referral center. Results Of 14 patients identified, clinical settings included bleb-associated (n=8), post-cataract surgery (n=4), and post-penetrating keratoplasty (n=2). All isolates were vancomycin sensitive. When comparing isolates in the current study to isolates from 1990–2001, the minimal inhibitory concentration required to inhibit 90% of isolates (MIC 90, μg/ml) increased for ciprofloxacin (4 from 1), erythromycin (256 from 4), and penicillin (8 from 4), indicating higher levels of resistance. The MIC 90 remained the same for vancomycin (2) and linezolid (2). Presenting VA ranged from hand motion to no light perception. Initial treatment strategies were vitreous tap and intravitreal antibiotic injection (n=12) and pars plana vitrectomy with intravitreal antibiotic injection (n=2). VA outcomes were ≤ 20/400 in 13 (93%) of 14 patients. Conclusions Although all isolates were sensitive to vancomycin and linezolid, higher MIC 90s for isolates in the current study, compared to isolates from 1990 to 2001, occurred with ciprofloxacin, erythromycin, and penicillin. Despite prompt treatment, most patients had poor outcomes. PMID:25089354

  20. Molecular epidemiology of Enterococcus cecorum isolates recovered from enterococcal spondylitis outbreaks in the southeastern United States.

    PubMed

    Borst, Luke B; Suyemoto, M Mitsu; Robbins, Kabel M; Lyman, Roberta L; Martin, Michael P; Barnes, H John

    2012-10-01

    Enterococcus cecorum, a normal intestinal inhabitant, is increasingly responsible for outbreaks of arthritis and osteomyelitis in chickens worldwide. Enterococcal spondylitis (ES) is a specific manifestation of E. cecorum-associated disease in which increased flock morbidity and mortality result from chronic infection involving the free thoracic vertebra. In this study the genetic relatedness and antimicrobial resistance of isolates recovered from ES-affected flocks in the southeastern United States were determined. ES outbreaks from 2007 to 2011 were investigated in North Carolina (15 flocks, 13 farms, four integrators), South Carolina (one flock, one farm, one integrator) and Alabama (six flocks, six farms, one integrator). From these 22 epidemiologically distinct outbreaks, 326 isolates of E. cecorum were recovered. Isolates from spinal lesions and caeca of affected birds (cases) and caeca of unaffected birds (controls) were genotyped using pulsed-field gel electrophoresis; phenotyped using both GenIII MicroPlate™ (Biolog; Hayward, CA, USA) microbial identification plates and antimicrobial sensitivity testing; and compared with each other. Isolates from spinal lesions were incapable of mannitol metabolism and the majority of these isolates were genetically clonal. In contrast, caecal isolates from control birds varied in their ability to metabolize mannitol and were genetically diverse. Isolates from both case and control birds had high levels of antimicrobial resistance. These findings indicate that the increase in E. cecorum-associated disease in the southeast United States is due to the emergence of new clones with increased pathogenicity and multidrug resistance.

  1. Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis

    PubMed Central

    Wang, Qian-Qian; Zhang, Cheng-Fei; Chu, Chun-Hung; Zhu, Xiao-Fei

    2012-01-01

    To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8–51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva. PMID:22422085

  2. Enterococcus faecalis reconfigures its gene regulatory network activation under copper exposure

    PubMed Central

    Latorre, Mauricio; Galloway-Peña, Jessica; Roh, Jung Hyeob; Budinich, Marko; Reyes-Jara, Angélica; Murray, Barbara E.; Maass, Alejandro; González, Mauricio

    2014-01-01

    A gene regulatory network was generated in the bacterium Enterococcus faecalis in order to understand how this organism can activate its expression under different copper concentrations. The topological evaluation of the network showed common patterns described in other organisms. Integrating microarray experiments allowed the identification of sub-networks activated under low (0.05 mM CuSO4) and high (0.5 mM CuSO4) copper concentrations. The analysis indicates the presence of specific functionally activated modules induced by copper, highlighting the regulons LysR, ArgR as global regulators and CopY, Fur and LexA as local regulators. Taking advantage of the fact that E. faecalis presented a homeostatic module isolated, we produced an in vivo intervention removing this system from the cell without affecting the connectivity of the global transcriptional network. This strategy led us to find that this bacterium can reconfigure its gene expression to maintain cellular homeostasis, activating new modules principally related to glucose metabolism and transcriptional processes. Finally, these results position E. faecalis as the organism having the most complete and controllable systemic model of copper homeostasis available to date. PMID:24382465

  3. Transmission and genetic diversity of Enterococcus faecalis during hatch of broiler chicks.

    PubMed

    Olsen, Rikke Heidemann; Christensen, Henrik; Bisgaard, Magne

    2012-11-09

    The normal gastrointestinal flora of poultry includes Enterococcus faecalis. E. faecalis is also associated with first week mortality of chickens, but it is not clear whether this is due to vertical or horizontal transmission. Aims of the present study were to investigate transmission and genetic diversity of E. faecalis during hatching of broiler chicks. When hatching started, 15% of the chicks were colonized with E. faecalis. This colonization was interpreted as vertical transmission and was higher than previously reported. Transmission of E. faecalis from parents older than 42 weeks was five times greater than transmission of E. faecalis from younger parents. Seventy percent of broiler chicks were colonized with E. faecalis within 24 h after hatch started, which was interpreted as horizontal transmission. Twenty-one sequence types (STs) were demonstrated among 322 isolates of E. faecalis obtained from newly hatched chicks representing 11 different broiler parent flocks. Furthermore, three STs (ST59, ST82, ST174) made up 50.6% of the isolates, indicating that these STs have adapted successfully to the avian niche. All STs, except those novel to this study, have previously been associated with lesions in poultry, underlining the importance of controlling these particular STs.

  4. Identification and characterization of vancomycin-resistant Enterococcus species frequently isolated from laboratory mice.

    PubMed

    Yamanaka, Hitoki; Takagi, Toshikazu; Ohsawa, Makiko; Yamamoto, Naoto; Kubo, Noriaki; Takemoto, Takahira; Sasano, Shoko; Masuyama, Ritsuko; Ohsawa, Kazutaka

    2014-01-01

    To determine the prevalence of drug resistant bacteria colonizing laboratory mice, we isolated and characterized vancomycin-resistant Enterococcus species (VRE) from commercially available mice. A total of 24 VRE isolates were obtained from 19 of 21 mouse strains supplied by 4 commercial breeding companies. Of these, 19 isolates of E. gallinarum and 5 isolates of E. casseliflavus possessing the vanC1 and vanC2/3 genes intrinsically, exhibited intermediate resistance to vancomycin respectively. In addition, these isolates also exhibited diverse resistant patterns to erythromycin, tetracycline, and ciprofloxacin, whereas the use of antibiotics had not been undertaken in mouse strains tested in this study. Although 6 virulence-associated genes (ace, asa, cylA, efaA, esp, and gelE) and secretion of gelatinase and hemolysin were not detected in all isolates, 23 of 24 isolates including the isolates of E. casselifalvus secreted ATP into culture supernatants. Since secretion of ATP by bacteria resident in the intestinal tract modulates the local immune responses, the prevalence of ATP-secreting VRE in mice therefore needs to be considered in animal experiments that alter the gut microflora by use of antibiotics.

  5. The Natural Surfactant Glycerol Monolaurate Significantly Reduces Development of Staphylococcus aureus and Enterococcus faecalis Biofilms

    PubMed Central

    Hess, Donavon J.; Henry-Stanley, Michelle J.

    2015-01-01

    Abstract Background: Bacterial biofilms are involved in a large proportion of clinical infections, including device-related infections. Unfortunately, biofilm-associated bacteria are typically less susceptible to antibiotics, and infected devices must often be removed. On the basis of a recent observation that lipid-rich biofilm matrix material is present in early biofilm formation and may protect a population of bacteria from interacting with ordinarily diffusible small molecules, we hypothesized that surfactants may be useful in preventing biofilm development. Methods: Experimental Staphylococcus aureus or Enterococcus faecalis biofilms were cultivated on surgical suture suspended in a growth medium supplemented with the natural surfactant glycerol monolaurate (GML) or with a component molecule, lauric acid. After 16 h incubation, the numbers of viable biofilm-associated bacteria were measured by standard microbiologic techniques and biofilm biomass was measured using the colorimetric crystal violet assay. Results: Both GML and lauric acid were effective in inhibiting biofilm development as measured by decreased numbers of viable biofilm-associated bacteria as well as decreased biofilm biomass. Compared with lauric acid on a molar basis, GML represented a more effective inhibitor of biofilms formed by either S. aureus or E. faecalis. Conclusions: Because the natural surfactant GML inhibited biofilm development, resulting data were consistent with the hypothesis that lipids may play an important role in biofilm growth, implying that interfering with lipid formation may help control development of clinically relevant biofilms. PMID:26110557

  6. Lipoteichoic acid synthesis inhibition in combination with antibiotics abrogates growth of multidrug-resistant Enterococcus faecium.

    PubMed

    Paganelli, Fernanda L; van de Kamer, Tim; Brouwer, Ellen C; Leavis, Helen L; Woodford, Neil; Bonten, Marc J M; Willems, Rob J L; Hendrickx, Antoni P A

    2017-03-01

    Enterococcus faecium is a multidrug-resistant (MDR) nosocomial pathogen causing significant morbidity in debilitated patients. New antimicrobials are needed to treat antibiotic-resistant E. faecium infections in hospitalised patients. E. faecium incorporates lipoteichoic acid (LTA) (1,3-polyglycerol-phosphate linked to glycolipid) in its cell wall. The small-molecule inhibitor 1771 [2-oxo-2-(5-phenyl-1,3,4-oxadiazol-2-ylamino)ethyl 2-naphtho[2,1-b]furan-1-ylacetate] specifically blocks the activity of Staphylococcus aureus LtaS synthase, which polymerises 1,3-glycerolphosphate into LTA polymers. Here we characterised the effects of the small-molecule inhibitor 1771 on the growth of E. faecium isolates, alone (28 strains) or in combination with the antibiotics vancomycin, daptomycin, ampicillin, gentamicin or linezolid (15 strains), and on biofilm formation (16 strains). Inhibition of LTA synthesis at the surface of the cell by compound 1771 in combination with current antibiotic therapy abrogates enterococcal growth in vitro but does not affect mature E. faecium biofilms. Targeting LTA synthesis may provide new possibilities to treat MDR E. faecium infections.

  7. Inorganic Cation Transport and Energy Transduction in Enterococcus hirae and Other Streptococci

    PubMed Central

    Kakinuma, Yoshimi

    1998-01-01

    Energy metabolism by bacteria is well understood from the chemiosmotic viewpoint. We know that bacteria extrude protons across the plasma membrane, establishing an electrochemical potential that provides the driving force for various kinds of physiological work. Among these are the uptake of sugars, amino acids, and other nutrients with the aid of secondary porters and the regulation of the cytoplasmic pH and of the cytoplasmic concentration of potassium and other ions. Bacteria live in diverse habitats and are often exposed to severe conditions. In some circumstances, a proton circulation cannot satisfy their requirements and must be supplemented with a complement of primary transport systems. This review is concerned with cation transport in the fermentative streptococci, particularly Enterococcus hirae. Streptococci lack respiratory chains, relying on glycolysis or arginine fermentation for the production of ATP. One of the major findings with E. hirae and other streptococci is that ATP plays a much more important role in transmembrane transport than it does in nonfermentative organisms, probably due to the inability of this organism to generate a large proton potential. The movements of cations in streptococci illustrate the interplay between a variety of primary and secondary modes of transport. PMID:9841664

  8. Evolutionary origins of the emergent ST796 clone of vancomycin resistant Enterococcus faecium

    PubMed Central

    Buultjens, Andrew H.; Lam, Margaret M.C.; Ballard, Susan; Monk, Ian R.; Mahony, Andrew A.; Grabsch, Elizabeth A.; Grayson, M. Lindsay; Pang, Stanley; Coombs, Geoffrey W.; Robinson, J. Owen; Seemann, Torsten; Howden, Benjamin P.

    2017-01-01

    From early 2012, a novel clone of vancomycin resistant Enterococcus faecium (assigned the multi locus sequence type ST796) was simultaneously isolated from geographically separate hospitals in south eastern Australia and New Zealand. Here we describe the complete genome sequence of Ef_aus0233, a representative ST796 E. faecium isolate. We used PacBio single molecule real-time sequencing to establish a high quality, fully assembled genome comprising a circular chromosome of 2,888,087 bp and five plasmids. Comparison of Ef_aus0233 to other E. faecium genomes shows Ef_aus0233 is a member of the epidemic hospital-adapted lineage and has evolved from an ST555-like ancestral progenitor by the accumulation or modification of five mosaic plasmids and five putative prophage, acquisition of two cryptic genomic islands, accrued chromosomal single nucleotide polymorphisms and a 80 kb region of recombination, also gaining Tn1549 and Tn916, transposons conferring resistance to vancomycin and tetracycline respectively. The genomic dissection of this new clone presented here underscores the propensity of the hospital E. faecium lineage to change, presumably in response to the specific conditions of hospital and healthcare environments. PMID:28149688

  9. Pheromone killing of multidrug-resistant Enterococcus faecalis V583 by native commensal strains

    PubMed Central

    Gilmore, Michael S.; Rauch, Marcus; Ramsey, Matthew M.; Himes, Paul R.; Varahan, Sriram; Manson, Janet M.; Lebreton, Francois; Hancock, Lynn Ernest

    2015-01-01

    Multidrug-resistant Enterococcus faecalis possess numerous mobile elements that encode virulence and antibiotic resistance traits as well as new metabolic pathways, often constituting over one-quarter of the genome. It was of interest to determine how this large accretion of mobile elements affects competitive growth in the gastrointestinal (GI) tract consortium. We unexpectedly observed that the prototype clinical isolate strain V583 was actively killed by GI tract flora, whereas commensal enterococci flourished. It was found that killing of V583 resulted from lethal cross-talk between accumulated mobile elements and that this cross-talk was induced by a heptapeptide pheromone produced by native E. faecalis present in the fecal consortium. These results highlight two important aspects of the evolution of multidrug-resistant enterococci: (i) the accretion of mobile elements in E. faecalis V583 renders it incompatible with commensal strains, and (ii) because of this incompatibility, multidrug-resistant strains sharing features found in V583 cannot coexist with commensal strains. The accumulation of mobile elements in hospital isolates of enterococci can include those that are inherently incompatible with native flora, highlighting the importance of maintaining commensal populations as means of preventing colonization and subsequent infection by multidrug-resistant strains. PMID:26039987

  10. A conserved hydrolase responsible for the cleavage of aminoacylphosphatidylglycerol in the membrane of Enterococcus faecium.

    PubMed

    Smith, Angela M; Harrison, Jesse S; Sprague, Kevin M; Roy, Hervé

    2013-08-02

    Aminoacylphosphatidylglycerol synthases (aaPGSs) are enzymes that transfer amino acids from aminoacyl-tRNAs (aa-tRNAs) to phosphatidylglycerol (PG) to form aa-PG in the cytoplasmic membrane of bacteria. aa-PGs provide bacteria with resistance to a range of antimicrobial compounds and stress conditions. Enterococcus faecium encodes a triple-specific aaPGS (RakPGS) that utilizes arginine, alanine, and lysine as substrates. Here we identify a novel hydrolase (AhyD), encoded immediately adjacent to rakPGS in E. faecium, which is responsible for the hydrolysis of aa-PG. The genetic synteny of aaPGS and ahyD is conserved in >60 different bacterial species. Deletion of ahyD in E. faecium resulted in increased formation of Ala-PG and Lys-PG and increased sensitivity to bacitracin. Our results suggest that AhyD and RakPGS act together to maintain optimal levels of aa-PG in the bacterial membrane to confer resistance to certain antimicrobial compounds and stress conditions.

  11. Genetic diversity of Enterococcus faecalis isolated from environmental, animal and clinical sources in Malaysia.

    PubMed

    Daniel, Diane S; Lee, Sui M; Gan, Han M; Dykes, Gary A; Rahman, Sadequr

    2017-02-18

    Enterococcus faecalis ranks as one of the leading causes of nosocomial infections. A strong epidemiological link has been reported between E. faecalis inhabiting animals and environmental sources. This study investigates the genetic diversity, antibiotic resistance and virulence determinants in E. faecalis from three sources in Malaysia. A total of 250 E. faecalis isolates were obtained consisting of 120 isolates from farm animals, 100 isolates from water sources and 30 isolates from hospitalized patients. Pulse-field gel electrophoresis-typing yielded 63 pulsotypes, with high diversity observed in all sources (D=≥0.901). No pulsotype was common to all the three sources. Each patient room had its own unique PFGE pattern which persisted after six months. Minimum inhibitory concentrations of Vancomycin, Gentamicin, Penicillin, Tetracycline, Nitrofurantoin, Levofloxacin, Ciprofloxacin and Fosfomycin were evaluated. Resistance to Tetracycline was most prevalent in isolates from farm animals (62%) and water sources (49%). Water isolates (86%) had a higher prevalence of the asa1 gene, which encodes for aggregation substance, whereas clinical (78%) and farm animal isolates (87%) had a higher prevalence of the esp gene, encoding a surface exposed protein. This study generates knowledge on the genetic diversity of E. faecalis with antibiotic resistance and virulence characteristics from various sources in Malaysia.

  12. Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis.

    PubMed

    Wang, Qian-Qian; Zhang, Cheng-Fei; Chu, Chun-Hung; Zhu, Xiao-Fei

    2012-03-01

    To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8-51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva.

  13. Duplex real-time PCR assay for rapid detection of ampicillin-resistant Enterococcus faecium.

    PubMed

    Mohn, Stein Christian; Ulvik, Arve; Jureen, Roland; Willems, Rob J L; Top, Janetta; Leavis, Helen; Harthug, Stig; Langeland, Nina

    2004-02-01

    Rapid and accurate identification of carriers of resistant microorganisms is an important aspect of efficient infection control in hospitals. Traditional identification methods of antibiotic-resistant bacteria usually take at least 3 to 4 days after sampling. A duplex real-time PCR assay was developed for rapid detection of ampicillin-resistant Enterococcus faecium (ARE). Primers and probes that are used in this assay specifically detected the D-Ala-D-Ala ligase gene of E. faecium and the modified penicillin-binding protein 5 gene (pbp5) carrying the Glu-to-Val substitution at position 629 (Val-629) in a set of 129 tested E. faecium strains with known pbp5 sequence. Presence of the Val-629 in the strain set from 11 different countries was highly correlated with ampicillin resistance. In a screening of hospitalized patients, the real-time PCR assay yielded a sensitivity and a specificity for the detection of ARE colonization of 95% and 100%, respectively. The results were obtained 4 h after samples were harvested from overnight broth of rectal swab samples, identifying both species and the resistance marker mutation in pbp5. This novel assay reliably identifies ARE 2 to 3 days more quickly than traditional culture methods, thereby increasing laboratory throughput, making it useful for rectal screening of ARE. The assay demonstrates the advantages of real-time PCR for detection of nosocomial pathogens.

  14. The antimicrobial effect of chloroform on Enterococcus faecalis after gutta-percha removal.

    PubMed

    Edgar, Scott W; Marshall, J Gordon; Baumgartner, J Craig

    2006-12-01

    The purpose of this in vitro study was to evaluate the antimicrobial effectiveness of chloroform on Enterococcus faecalis when used as a gutta-percha solvent during endodontic retreatment. Bilaterally matched human teeth were instrumented, infected with E. faecalis, and obturated. The gutta-percha was then removed using either chloroform or saline. Bacterial samples were collected after gutta-percha removal and following additional apical enlargement. A significant difference was seen (p<0.05) between the number of colony forming units (CFU) of E. faecalis for teeth retreated using chloroform (mean 21+56 CFU/ml) versus saline (mean 280+480 CFU/ml). Negative cultures were obtained in 11 of 17 chloroform samples and none of the saline samples. Samples taken after apical enlargement two sizes larger than the original master apical file showed a significant difference (p<0.05) between teeth retreated using chloroform versus saline. Negative cultures were seen in 9 of 17 chloroform samples and 1 of 17 saline samples. This study demonstrated that the use of chloroform during endodontic retreatment significantly reduced intracanal levels of cultivatable E. faecalis.

  15. The in vitro Effect of Irrigants with Low Surface Tension on Enterococcus faecalis

    PubMed Central

    Giardino, Luciano; Estrela, Carlos; Generali, Luigi; Mohammadi, Zahed; Asgary, Saeed

    2015-01-01

    Introduction: Due to the complex anatomy of the root canal system and high surface tension of common root canal irrigants (RCI), conducting an investigation on RCIs containing surfactants is a priority. The aim of this in vitro study was to verify the antibacterial potential of RCI with low surface tension in root canals infected with Enterococcus faecalis (E. faecalis). Methods and Materials: Thirty-five extracted human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. After root canal preparation, the teeth were randomly divided to one positive and one negative control groups and 5 experimental groups: Hypoclean/Tetraclean NA, Hypoclean, Tetraclean, NaOCl/Tetraclean and NaOCl. Bacterial growth was observed by turbidity of culture medium and then measured using a UV spectrophotometer. Data were analyzed in three time intervals (pre-instrumentation and, 20 min and 72 h after canal preparation) using the ANOVA and post hoc Tukey’s tests. The level of significance was set at 0.05. Results: The results indicated the presence of E. faecalis in all post-irrigation samples irrespective of the RCI. However, the optical densities in both post-irrigation periods showed bacterial reduction and significant differences between groups. Conclusion: RCI with low surface tension showed antibacterial potential in E. faecalis infected roots. PMID:26229541

  16. Raising the Alarmone: Within-Host Evolution of Antibiotic-Tolerant Enterococcus faecium

    PubMed Central

    2017-01-01

    ABSTRACT Enterococci are ancient commensal bacteria that recently emerged as leading causes of antibiotic-resistant, hospital-acquired infection. Vancomycin-resistant enterococci (VRE) epitomize why drug-resistant enterococcal infections are a problem: VRE readily colonize the antibiotic-perturbed gastrointestinal (GI) tract where they amplify to large numbers, and from there, they infect other body sites, including the bloodstream, urinary tract, and surgical wounds. VRE are resistant to many antimicrobials and host defenses, which facilitates establishment at the site of infection and confounds therapeutic clearance. Having evolved to colonize the GI tract, VRE are comparatively ill adapted to the human bloodstream. A recent study by Honsa and colleagues (E. S. Honsa et al., mBio 8:e02124-16, 2017, https://doi.org/10.1128/mBio.02124-16) found that a strain of vancomycin-resistant Enterococcus faecium evolved antibiotic tolerance within the bloodstream of an immunocompromised host by activating the stringent response through mutation of relA. Precisely how VRE colonize and infect and the selective pressures that led to the outgrowth of relA mutants are the subjects of ongoing research. PMID:28223450

  17. Enterococcal surface protein Esp is important for biofilm formation of Enterococcus faecium E1162.

    PubMed

    Heikens, Esther; Bonten, Marc J M; Willems, Rob J L

    2007-11-01

    Enterococci have emerged as important nosocomial pathogens with resistance to multiple antibiotics. Adhesion to abiotic materials and biofilm formation on medical devices are considered important virulence properties. A single clonal lineage of Enterococcus faecium, complex 17 (CC17), appears to be a successful nosocomial pathogen, and most CC17 isolates harbor the enterococcal surface protein gene, esp. In this study, we constructed an esp insertion-deletion mutant in a clinical E. faecium CC17 isolate. In addition, initial adherence and biofilm assays were performed. Compared to the wild-type strain, the esp insertion-deletion mutant no longer produced Esp on the cell surface and had significantly lower initial adherence to polystyrene and significantly less biofilm formation, resulting in levels of biofilm comparable to those of an esp-negative isolate. Capacities for initial adherence and biofilm formation were restored in the insertion-deletion mutant by in trans complementation with esp. These results identify Esp as the first documented determinant in E. faecium CC17 with an important role in biofilm formation, which is an essential factor in infection pathogenesis.

  18. Proteolytic activity of Enterococcus faecalis VB63F for reduction of allergenicity of bovine milk proteins.

    PubMed

    Biscola, V; Tulini, F L; Choiset, Y; Rabesona, H; Ivanova, I; Chobert, J-M; Todorov, S D; Haertlé, T; Franco, B D G M

    2016-07-01

    With the aim of screening proteolytic strains of lactic acid bacteria to evaluate their potential for the reduction of allergenicity of the major bovine milk proteins, we isolated a new proteolytic strain of Enterococcus faecalis (Ent. faecalis VB63F) from raw bovine milk. The proteases produced by this strain had strong activity against caseins (αS1-, αS2-, and β-casein), in both skim milk and sodium caseinate. However, only partial hydrolysis of whey proteins was observed. Proteolysis of Na-caseinate and whey proteins, observed after sodium dodecyl sulfate-PAGE, was confirmed by analysis of peptide profiles by reversed-phase HPLC. Inhibition of proteolysis with EDTA indicated that the proteases produced by Ent. faecalis VB63F belonged to the group of metalloproteases. The optimal conditions for their activity were 42°C and pH 6.5. The majority of assessed virulence genes were absent in Ent. faecalis VB63F. The obtained results suggest that Ent. faecalis VB63F could be efficient in reducing the immunoreactivity of bovine milk proteins.

  19. Screening of Bacteriocin-producing Enterococcus faecalis Strains for Antagonistic Activities against Clostridium perfringens

    PubMed Central

    Kim, So-Young

    2014-01-01

    This study was conducted to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens (C. perfringens) from domestic animals to determine their usefulness as probiotics. Bacteriocin-producing bacteria were isolated from pig feces by the spot-on-lawn method. A total of 1,370 bacterial stains were isolated, and six were tentatively selected after identifying the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269 and KCTC 5100. The selected strains were identified as Enterococcus faecalis (E. faecalis) by 16s rRNA sequencing. Most of the isolated bacterial strains were resistant to 0.5% bile salts for 48 h and remained viable after 2 h at pH 3.0. Some E. faecalis also showed strong inhibitory activity against Listeria monocytogenes KCTC 3569, KCTC 3586 and KCTC 3710. In the present study, we finally selected E. faecalis AP 216 and AP 45 strain based on probiotic selection criteria such as antimicrobial activity against C. perfringens and tolerance to acid and bile salts. The bacteriocins of E. faecalis AP 216 and AP 45 strains were highly thermostable, showing anticlostridial activities even after incubation at 121℃ for 15 min. These bacteriocinproducing bacteria and/or bacteriocins could be used in feed manufacturing as probiotics as an alternative to antibiotics in the livestock industry. PMID:26761495

  20. Transcriptome profiling of TDC cluster deletion mutant of Enterococcus faecalis V583.

    PubMed

    Perez, Marta; Ladero, Victor; Del Rio, Beatriz; Redruello, Begoña; de Jong, Anne; Kuipers, Oscar P; Kok, Jan; Martin, M Cruz; Fernandez, Maria; Alvarez, Miguel A

    2016-09-01

    The species Enterococcus faecalis is able to catabolise the amino acid tyrosine into the biogenic amine tyramine by the tyrosine decarboxilase (TDC) pathway Ladero et al. (2012) [1]. The TDC cluster comprises four genes: tyrS, an aminoacyl-tRNA synthetase-like gene; tdcA, which encodes the tyrosine decarboxylase; tyrP, a tyrosine/tyramine exchanger gene and nhaC-2, which encodes an Na(+)/H(+) antiporter and whose role in the tyramine biosynthesis remains unknown [2]. In E. faecalis V583 the last three genes are co-transcribed as a single polycistronic mRNA forming the catabolic operon, while tyrS is transcribed independently of the catabolic genes as a monocistronic mRNA [2]. The catabolic operon is transcriptionally induced by tyrosine and acidic pH. On the opposite, the tyrS expression is repressed by tyrosine concentrations [2]. In this work we report the transcriptional profiling of the TDC cluster deletion mutant (E. faecalis V583 ΔTDC) [2] compared to the wild-type strain, both grown in M17 medium supplemented with tyrosine. The transcriptional profile data of TDC cluster-regulated genes were deposited in the Gene Expression Omnibus (GEO) database under accession no. GSE77864.

  1. vanE gene cluster of vancomycin-resistant Enterococcus faecalis BM4405.

    PubMed

    Abadía Patiño, Lorena; Courvalin, Patrice; Perichon, Bruno

    2002-12-01

    Acquired VanE-type resistance to low levels of vancomycin (MIC = 16 microg/ml) in Enterococcus faecalis BM4405 is due to the inducible synthesis of peptidoglyean precursors terminating in D-alanine-D-serine (Fines,M., B. Prichon, P. Reynolds, D. Sahm, and P. Courvalin, Antimicrob. Agents Chemother. 43:2161-2164, 1999). A chromosomal location was assigned to the vanE operon by pulsed-field gel electrophoresis and hybridization, and its sequence was determined. Three genes, encoding the VanE ligase, the VanXYE DD-peptidase, and the VanTE serine racemase, that displayed 43 to 53% identity with the corresponding genes in the vanC operon were found. In addition, two genes coding for a two-component regulatory system, VanRE-VanSE, exhibiting 60 and 44% identity with VanR,-VanS, were present downstream from vanTE. However, because of a stop codon at position 78, VanSE was probably not functional. The five genes, with the same orientation, were shown to be cotranscribed by Northern analysis and reverse transcription-PCR. The vanE, vanXYE, and vanTE genes conferred inducible low-level resistance to vancomycin after cloning in E. faecalis JH2-2, probably following cross talk with a two-component regulatory system of the host.

  2. Phage endolysins with broad antimicrobial activity against Enterococcus faecalis clinical strains.

    PubMed

    Proença, Daniela; Fernandes, Sofia; Leandro, Clara; Silva, Filipa Antunes; Santos, Sofia; Lopes, Fátima; Mato, Rosario; Cavaco-Silva, Patrícia; Pimentel, Madalena; São-José, Carlos

    2012-06-01

    Increasing antibiotic resistance of bacterial pathogens has drawn the attention to the potential use of bacteriophage endolysins as alternative antibacterial agents. Here we have identified, characterized, and studied the lytic potential of two endolysins, Lys168 and Lys170, from phages infecting Enterococcus faecalis. Lys168 and Lys170 belong to the cysteine, histidine-dependent amidohydrolases/peptidases (CHAP) and amidase-2 protein families, respectively. Lys168 is quite a unique enterococcal phage endolysin. It shares 95% amino acidic identity with the endolysin of Staphylococcus aureus phage SAP6, which in turn is distantly related to all known CHAP endolysins of S. aureus phages. Lys170 seems to be a natural chimera assembling catalytic and cell-wall-binding domains of different origin. Both endolysins showed a clear preference to act against E. faecalis and they were able to lyse a high proportion of clinical isolates of this species. Specifically, Lys168 and Lys170 lysed more than 70% and 90% of the tested isolates, respectively, which included a panel of diverse and typed strains representative of highly prevalent clonal complexes. Lys170 was active against all tested E. faecalis VRE strains. The quasi specificity toward E. faecalis is discussed considering the nature of the enzymes' functional domains and the structure of the cell wall peptidoglycan.

  3. Bactericidal effect of plasma jet with helium flowing through 3% hydrogen peroxide against Enterococcus faecalis.

    PubMed

    Zhou, Xin-Cai; Li, Yu-Lan; Liu, De-Xi; Cao, Ying-Guang; Lu, Xin-Pei

    2016-11-01

    The aim of the present study was to assess the antimicrobial activity of plasma jet with helium (He) flowing through 3% hydrogen peroxide in root canals infected with Enterococcus faecalis. A total of 42 single-rooted anterior teeth were prepared, sterilized, inoculated with an E. faecalis suspension and incubated for 7 days. Next, the teeth were randomly divided into six experimental groups (including groups treated by plasma jet with or without He for different time durations) and one control group treated without plasma. The number of surviving bacteria in each canal was determined by counting the colony forming units (CFU)/ml on nutrient agar plates. The results indicated that statistically significant reduction in CFU/ml (P<0.005) existed for all treatment groups relative to the control group. The greatest reductions in CFU/ml were observed for Group 3 (7.027 log unit reduction) and Group 2 (6.237 log unit reduction), which were treated by plasma jet sterilization with He flowing through 3% hydrogen peroxide for 4 min or for 2 min, respectively. In addition, the reduction in Group 3 was significantly greater compared with that in Group 2 or in the groups treated by plasma jet sterilization without He flowing through 3% hydrogen peroxide for 1, 2 or 4 min. In conclusion, plasma jet with or without He flowing through 3% hydrogen peroxide can effectively sterilized root canals infected with E. faecalis and should be considered as an alternative method for root canal disinfection in endodontic treatments.

  4. Multi-drug-resistant Enterococcus faecalis among Egyptian patients with urinary tract infection.

    PubMed

    Abdelkareem, Mohammad Z; Sayed, Mohamed; Hassuna, Noha A; Mahmoud, Mahmoud S; Abdelwahab, Sayed F

    2017-04-01

    The prevalence of Enterococcus faecalis (E. faecalis) infections among Egyptians with urinary tract infection (UTI), their antimicrobial susceptibility and mechanisms of resistance are under investigated. In this study, 300 urine samples were collected from UTI patients to identify E. faecalis. Antimicrobial susceptibility to 18 antimicrobial agents was tested. The presence of aac(6)-Ie-aph(2)Ia, erm(B) and mef(A/E) genes was examined by PCR. Fifty-seven (19%) isolates were identified as E. faecalis. All isolates were sensitive to teicoplanin and were completely resistant to nalidixic acid, cefotaxime and cefadroxil. Multi-drug-resistant (MDR) was found to be 100% with 45 different antibiotypes. The aac(6)Ia-aph(2)Ia gene was found in 100 and 90% of the isolates resistant to gentamicin at concentrations of 120 and 10 μg, respectively. erm(B) and mef(A/E) genes were present in 92.5% (37/40) and 2.5% (1/40) of erythromycin-resistant isolates, respectively. We conclude that there is a high prevalence of E. faecalis in UTI cases with a 100% MDR rate indicating a serious problem in treating infections by this organism in Egypt.

  5. Antimicrobial Activity of Calcium Hydroxide and Betamethasone on Enterococcus faecalis; An in vitro Assessment

    PubMed Central

    Tabrizizadeh, Mahdi; Rasti, Mojtaba; Ayatollahi, Fatemeh; Mossadegh, Mohammad Hossein; Zandi, Hengameh; Dehghan, Farzad; Mousavi, Zohreh

    2015-01-01

    Introduction: Calcium hydroxide (CH) is one of the most common intracanal medications. Corticosteroids (CS) are used in endodontics because of their anti-inflammatory activity. This study aimed to evaluate the antimicrobial effect of CH+betamethasone and CH+saline against Enterococcus faecalis (E. faecalis) using agar diffusion test and measuring the microbial zone of inhibition (ZOI). Methods and Materials: Four plates containing Mueller-Hinton broth and E. faecalis culture media, were prepared. In each plate, 5 holes (5×3 mm) were created and a creamy mixture of CH+betamethasone was inserted into the holes (10 holes for each material). Two holes with ampicillin disks and two empty holes were used as negative and positive controls, respectively. Plates were incubated for 24 h and then the diameter of microbial ZOI was measured. The pH of each mixture was measured by pH meter. Data were analyzed using the Mann-Whitney U test. Results: The mean diameter of ZOI for CH+betamethasone and CH+saline was 3.4 and 3 mm, respectively. The difference was not significant (P=0.143). The pH was 12.5 for CH+saline and 12.3 CH+betamethasone, respectively. Conclusion: The mixture of CH+betamethasone had good antimicrobial effects against E. faecalis. Further studies are needed to confirm the value of this mixture in clinical settings. PMID:26213541

  6. Overexpression, crystallization and preliminary X-ray crystallographic analysis of phosphopantetheine adenylyltransferase from Enterococcus faecalis

    SciTech Connect

    Kang, Ji Yong; Lee, Hyung Ho; Yoon, Hye Jin; Kim, Hyoun Sook; Suh, Se Won

    2006-11-01

    Phosphopantetheine adenylyltransferase from En. faecalis was crystallized and X-ray diffraction data were collected to 2.70 Å resolution. Phosphopantetheine adenylyltransferase, an essential enzyme in the coenzyme A biosynthetic pathway, catalyzes the reversible transfer of an adenylyl group from ATP to 4′-phosphopantetheine, yielding 3′-dephospho-CoA and pyrophosphate. Enterococcus faecalis PPAT has been overexpressed in Escherichia coli as a fusion with a C-terminal purification tag and crystallized at 297 K using a reservoir solution consisting of 0.1 M sodium HEPES pH 7.5, 0.8 M sodium dihydrogen phosphate and 0.8 M potassium dihydrogen phosphate. X-ray diffraction data were collected to 2.70 Å at 100 K. The crystals belong to the primitive tetragonal space group P4{sub 1} (or P4{sub 3}), with unit-cell parameters a = b = 160.81, c = 225.68 Å. Four copies of the hexameric molecule are likely to be present in the asymmetric unit, giving a crystal volume per protein weight (V{sub M}) of 3.08 Å{sup 3} Da{sup −1} and a solvent content of 60.1%.

  7. Bactericial effect of a non-thermal plasma needle against Enterococcus faecalis biofilms

    NASA Astrophysics Data System (ADS)

    Jiang, Chunqi; Schaudinn, C.; Jaramillo, D. E.; Sedghizadeh, P. P.; Webster, P.; Costerton, J. W.

    2011-10-01

    Up to 3 cm long submillimeter-in-scale plasma needle was generated in ambient atmosphere for root canal disinfection. Powered with 1-2 kHz, multi-kilovolt nanosecond electric pulses, this He/(1%)O2 plasma jet consists of ionization fronts propagating at speeds of the order of 107 cm/s. Plasma treatment of Enterococcus faecalis biofilms on hydroxyapatite (HA) discs for 5 min resulted in severe damage of the bacterial cells and sterilized HA surfaces of more than 3 mm in diameter, observed by the scanning electron microscopy. With a curing dielectric microtube placed 1 cm or less below the nozzle, the plasma jet entered even at a sharp angle and followed the curvature of the tube, and reached the bottom of the tube. The bactericidal effect of the plasma needle against E. faecalis biofilm grown on the inner surfaces of the tube was demonstrated. However, the bactericidal effect weakens or diminishes for the bacteria grown deeper in the tube, indicating improvement of the plasma treatment scheme is needed. Mechanisms of the plasma bactericidal effects are discussed. Supported by the National Institute of Dental and Craniofacial Research and the Air Force Office of Scientific Research.

  8. Antimicrobial resistance, virulence determinants and genetic profiles of clinical and nonclinical Enterococcus cecorum from poultry.

    PubMed

    Jackson, C R; Kariyawasam, S; Borst, L B; Frye, J G; Barrett, J B; Hiott, L M; Woodley, T A

    2015-02-01

    Enterococcus cecorum has been implicated as a possible cause of disease in poultry. However, the characteristics that contribute to pathogenesis of Ent. cecorum in poultry have not been defined. In this study, Ent. cecorum from carcass rinsates (n = 75) and diseased broilers and broiler breeders (n = 30) were compared based upon antimicrobial resistance phenotype, the presence of virulence determinants and genetic relatedness using pulsed-field gel electrophoresis (PFGE). Of the 16 antimicrobials tested, Ent. cecorum from carcass rinsates and clinical cases were resistant to ten and six of the antimicrobials, respectively. The majority of Ent. cecorum from carcass rinsates was resistant to lincomycin (54/75; 72%) and tetracycline (46/75; 61.3%) while the highest level of resistance among clinical Ent. cecorum was to tetracycline (22/30; 73.3%) and erythromycin (11/30; 36.7%). Multidrug resistance (resistance to ≥2 antimicrobials) was identified in Ent. cecorum from carcass rinsates (53/75; 70.7%) and diseased poultry (18/30; 60%). Of the virulence determinants tested, efaAfm was present in almost all of the isolates (104/105; 99%). Using PFGE, the majority of clinical isolates clustered together; however, a few clinical isolates grouped with Ent. cecorum from carcass rinsates. These data suggest that distinguishing the two groups of isolates is difficult based upon the characterization criteria used.

  9. Aerobic degradation of BDE-209 by Enterococcus casseliflavus: Isolation, identification and cell changes during degradation process.

    PubMed

    Tang, Shaoyu; Yin, Hua; Chen, Shuona; Peng, Hui; Chang, Jingjing; Liu, Zehua; Dang, Zhi

    2016-05-05

    Decabromodiphenyl ether (BDE-209) is one of the most commonly used brominated flame retardants that have contaminated the environment worldwide. Microbial bioremediation has been considered as an effective technique to remove these sorts of persistent organic pollutants. Enterococcus casseliflavus, a gram-positive bacterium capable of aerobically transforming BDE-209, was isolated by our team from sediments in Guiyu, an e-waste dismantling area in Guangdong Province, China. To promote microbial bioremediation of BDE-209 and elucidate the mechanism behind its aerobic degradation, the effects of BDE-209 on the cell changes of E. casseliflavus were examined in this study. The experimental results demonstrated that the high cell surface hydrophobicity (CSH) of E. casseliflavus made the bacteria absorb hydrophobic BDE-209 more easily. E. casseliflavus responded to BDE-209 stress, resulting in an increase in cell membrane permeability and accumulation of BDE-209 inside the cell. The differential expression of intracellular protein was analyzed through two-dimensional gel electrophoresis (2-DE). More than 50 differentially expressed protein spots were reproducibly detected, including 25 up, and 25 down regulated after a 4 days exposure. Moreover, the apoptotic-like cell changes were observed during E. casseliflavus mediated degradation of BDE-209 by means of flow cytometry.

  10. Differences in the chemical composition of Enterococcus faecalis biofilm under conditions of starvation and alkalinity.

    PubMed

    Chen, Weixu; Liang, Jingping; He, Zhiyan; Jiang, Wei

    2017-01-02

    ABSTACT This study aimed to investigate the dynamic changes that occur in the chemical composition of an Enterococcus faecalis (E. faecalis) biofilm under conditions of starvation and in an alkaline environment and to explore the function of chemical composition changes in the resistance of the E. faecalis biofilm to an extreme environment. This study established an in vitro E. faecalis biofilm model under starvation and in an alkaline environment. During the formation of the biofilm, the pH value and nutritional condition of the culture medium were changed, and the changes in chemical composition were observed using biochemical measures. The results showed that, when the pH value of the culture medium was 11, the percentage of water-insoluble polysaccharides in the biofilm was significantly lower than under other conditions. In addition, the percentage of water-soluble polysaccharides in culture medium with pH values of 9 and 11 gradually decreased. The level of the water-soluble polysaccharides in each milligram of dry weight of biofilm at pH 11 increased compared to that under other conditions. The results from this study indicate that the chemical composition of E. faecalis biofilm changed in extreme environments. These changes served as a defensive mechanism for E. faecalis against environmental pressures.

  11. Confocal microscopy evaluation of the effect of irrigants on Enterococcus faecalis biofilm: An in vitro study.

    PubMed

    Flach, Nicole; Böttcher, Daiana Elisabeth; Parolo, Clarissa Cavalcanti Fatturi; Firmino, Luciana Bitello; Malt, Marisa; Lammers, Marcelo Lazzaron; Grecca, Fabiana Soares

    2016-01-01

    The purpose of this study was to evaluate in vitro the effectiveness of two endodontic irrigants and their association against Enterococcus faecalis (E. faecalis) by confocal laser scanning microscope (CLSM). Twenty-four bovine incisors were inoculated in a monoculture of E. faecalis for 21 days. After this period, the teeth were divided into three test groups (n = 5) according to the chemical used. Group 1: 2.5% sodium hypochlorite (NaOCl), group 2: 2% chlorhexidine gel (CHX), group 3: 2.5% NaOCl + 2% CHX gel, and two control groups (n = 3): negative control group (NCG)-sterile and without root canals preparation and positive control group (PCG)-saline. Then, the samples were stained with SYTO9 and propidium iodide and subjected to analysis by CLSM. Bacterial viability was quantitatively analyzed by the proportions of dead and live bacteria in the biofilm remnants. Statistical analysis was performed by the One-way ANOVA test (p = 0.05). No statistical differences were observed to bacterial viability. According to CLSM analysis, none of the tested substances could completely eliminate E. faecalis from the root canal space. Until now, there are no irrigant solutions able to completely eliminate E. faecalis from the root canal. In this regard, the search for irrigants able to intensify the antimicrobial action is of paramount importance.

  12. Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress.

    PubMed

    Abrantes, Marta C; Kok, Jan; Silva Lopes, Maria de Fátima

    2014-12-01

    Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn(2+)-responsive DNA-binding motif (zim) is present in the promoter regions of these genes. Both proteins were further studied with respect to their involvement in zinc homeostasis and invasion of the host. EF0759 contributed to intramacrophage survival by an as-yet unknown mechanism(s). EF1400, here renamed ZntAEf, is an ATPase with specificity for zinc and plays a role in dealing with several host defences, i.e. zinc overload, oxidative stress and lysozyme; it provides E. faecalis cells with the ability to survive inside macrophages. As these three host defence mechanisms are important at several sites in the host, i.e. inside macrophages and in saliva, this work suggested that ZntAEf constitutes a crucial E. faecalis defence mechanism that is likely to contribute to the ability of this bacterium to endure life inside its host.

  13. Increased Enterococcus faecalis infection is associated with clinically active Crohn disease.

    PubMed

    Zhou, Youlian; Chen, Huiting; He, Hanchang; Du, Yanlei; Hu, Jiaqi; Li, Yingfei; Li, Yuyuan; Zhou, Yongjian; Wang, Hong; Chen, Ye; Nie, Yuqiang

    2016-09-01

    This study was performed to investigate the relationship between the abundance of pathogenic gut microbes in Chinese patients with inflammatory bowel disease (IBD) and disease severity.We collected clinical data and fecal samples from 47 therapy-naive Chinese patients with ulcerative colitis (UC), 67 patients with Crohn disease (CD), and 48 healthy volunteers. Bacteria levels of Fusobacterium species (spp), enterotoxigenic Bacteroides fragilis (B fragilis), enteropathogenic Escherichia coli (E coli), and Enterococcus faecalis (E faecalis) were assessed by quantitative real-time PCR (qRT-PCR). Spearman correlation coefficients were calculated to test associations between bacterial content and clinical parameters.Compared to healthy controls, the levels of both Fusobacterium spp and E faecalis were significantly increased in the feces of patients with IBD (P < 0.01). B fragilis levels were higher (P < 0.05) and E faecalis levels lower (P < 0.05) in patients with CD compared to those with UC. Increased E faecalis colonization in CD associated positively with disease activity (P = 0.015), Crohn disease activity index (CDAI; R = 0.3118, P = 0.0108), and fecal calprotectin (P = 0.016).E faecalis and Fusobacterium spp are significantly enriched in patients with IBD, and increased E faecalis infection is associated with clinically active CD.

  14. Involvement of PhoP-PhoS homologs in Enterococcus faecalis virulence.

    PubMed

    Teng, Fang; Wang, Ling; Singh, Kavindra V; Murray, Barbara E; Weinstock, George M

    2002-04-01

    Eleven PhoP-PhoS homolog pairs were identified by searching the Enterococcus faecalis V583 genome sequence database at The Institute for Genomic Research with the Bacillus subtilis PhoP-PhoS sequences. Each pair appears to be a potential two-component system composed of a response regulator and a sensor kinase. Seven of the homologs were disrupted in E. faecalis strain OG1RF. TX10293, a mutant disrupted in one of these genes (etaR, the first gene of the gene pair designated etaRS), showed delayed killing and a higher 50% lethal dose in a mouse peritonitis model. The predicted EtaR protein sequence showed greatest similarity to LisR of Listeria monocytogenes (77%) and CsrR of Streptococcus pyogenes (70%); EtaS is 53% similar to LisK and 54% similar to CsrS. When grown in vitro, the TX10293 mutant was more sensitive to low pH (pH 3.4) and more resistant to high temperature (55 degrees C) than wild-type OG1RF. In conclusion, many potential two-component systems are identified for E. faecalis, one of which, EtaRS, was shown to be involved in stress response and virulence.

  15. Genome-based characterization of hospital-adapted Enterococcus faecalis lineages

    PubMed Central

    Raven, Kathy E.; Reuter, Sandra; Gouliouris, Theodore; Reynolds, Rosy; Russell, Julie E.; Brown, Nicholas M.; Török, M. Estée; Parkhill, Julian; Peacock, Sharon J.

    2016-01-01

    Vancomycin-resistant Enterococcus faecalis (VREfs) is an important nosocomial pathogen1,2. We undertook whole genome sequencing of E. faecalis associated with bloodstream infection in the UK and Ireland over more than a decade to determine the population structure and genetic associations with hospital adaptation. Three lineages predominated in the population, two of which (L1 and L2) were nationally distributed, and one (L3) geographically restricted. Genome comparison with a global collection identified that L1 and L3 were also present in the USA, but were genetically distinct. Over 90% of VREfs belonged to L1–L3, with resistance acquired and lost multiple times in L1 and L2, but only once followed by clonal expansion in L3. Putative virulence and antibiotic resistance genes were over-represented in L1, L2 and L3 isolates combined, versus the remainder. Each of the three main lineages contained a mixture of vancomycin-resistant and -susceptible E. faecalis (VSEfs), which has important implications for infection control and antibiotic stewardship. PMID:27213049

  16. Detection of the macrolide-efflux protein A gene mef(A) in Enterococcus faecalis.

    PubMed

    Schwaiger, Karin; Hölzel, Christina; Bauer, Johann

    2011-09-01

    The mef(A) gene codes for an efflux protein that conveys resistance to 14- and 15-membered macrolides. Enterococci are emerging pathogens, as well as indicator and reservoir bacteria that are known to have a strong tendency to acquire resistance genes. A total of 485 Enterococcus faecalis strains of porcine (n = 239) and human origin (n = 246) were screened for the presence of the mef(A) gene by using polymerase chain reaction. In total, 29 E. faecalis of porcine (n = 10) and human (n = 19) origin were positive for the presence of the mef(A) gene. Most of the mef(A)-containing strains were isolated from fecal samples of healthy individuals; only one strain originated from a stool sample of a diseased pig. To our knowledge, this is the first report on the occurrence of the mef(A) gene in E. faecalis apart from mating experiments. The main clinical relevance of this study is that donor E. faecalis might transfer the mef(A) gene to recipients that are usually combated with macrolides. Hence, the role of E. faecalis as a resistance reservoir with respect to limited treatment options are a cause for concern.

  17. Enterococcus faecalis Clones in Poultry and in Humans with Urinary Tract Infections, Vietnam

    PubMed Central

    Poulsen, Louise Ladefoged; Bisgaard, Magne; Son, Nguyen Thai; Trung, Nguyen Vu; An, Hoang Manh

    2012-01-01

    Enterococcus spp. as pathogens have increased, but the sources of infection often remain unclear. To investigate whether poultry might be a reservoir for E. faecalis–associated urinary tract infections (UTIs) in humans, we characterized E. faecalis isolates from patients in Vietnam with UTIs during January 2008–January 2010 and poultry living in close contact with them by multilocus sequence typing (MLST), pulsed-field gel electrophoresis, analysis of antimicrobial drug susceptibility patterns, and sequencing of virulence genes. In 7 (23%) of 31 UTI cases, we detected identical MLST, indistinguishable or closely related pulsed-field gel electrophoresis patterns, and similar antimicrobial drug susceptibility patterns. Isolates from urine and poultry showed identical virulence gene profiles, except for 1 variation, and individual genes showed identical sequences. The homology of isolates from urine and poultry further indicates the zoonotic potential and global spread of E. faecalis sequence type 16, which recently was reported in humans with endocarditis and in pigs in Denmark. PMID:22709904

  18. Cloning and sequence analysis of the muramidase-2 gene from Enterococcus hirae.

    PubMed Central

    Chu, C P; Kariyama, R; Daneo-Moore, L; Shockman, G D

    1992-01-01

    Extracellular muramidase-2 of Enterococcus hirae ATCC 9790 was purified to homogeneity by substrate binding, guanidine-HCl extraction, and reversed-phase chromatography. A monoclonal antibody, 2F8, which specifically recognizes muramidase-2, was used to screen a genomic library of E. hirae ATCC 9790 DNA in bacteriophage lambda gt11. A positive phage clone containing a 4.5-kb DNA insert was isolated and analyzed. The EcoRI-digested 4.5-kb fragment was cut into 2.3-, 1.0-, and 1.5-kb pieces by using restriction enzymes KpnI, Sau3AI, and PstI, and each fragment was subcloned into plasmid pJDC9 or pUC19. The nucleotide sequence of each subclone was determined. The sequence data indicated an open reading frame encoding a polypeptide of 666 amino acid residues, with a calculated molecular mass of 70,678 Da. The first 24 N-terminal amino acids of purified extracellular muramidase-2 were in very good agreement with the deduced amino acid sequence after a 49-amino-acid putative signal sequence. Analysis of the deduced amino acid sequence showed the presence at the C-terminal region of the protein of six highly homologous repeat units separated by nonhomologous intervening sequences that are highly enriched in serine and threonine. The overall sequence showed a high degree of homology with a recently cloned Streptococcus faecalis autolysin. Images PMID:1347040

  19. Assessment of pheromone response in biofilm forming clinical isolates of high level gentamicin resistant Enterococcus faecalis.

    PubMed

    Jayanthi, S; Ananthasubramanian, M; Appalaraju, B

    2008-01-01

    Twenty five clinical isolates of high level gentamicin resistant Enterococcus faecalis were tested for their biofilm formation and pheromone responsiveness. The biofilm assay was carried out using microtiter plate method. Two isolates out of the 25 (8%) were high biofilm formers and 19 (76%) and four (16%) isolates were moderate and weak biofilm formers respectively. All the isolates responded to pheromones of E. faecalis FA2-2 strain. On addition of pheromone producing E. faecalis FA2-2 strain to these isolates, seven of 19 (37%) moderate biofilm formers developed into high biofilm formers. Similarly one of the 4 (25%) weak biofilm formers developed into high level biofilm former. Twelve (48%) of the 25 isolates were transconjugated by cross streak method using gentamicin as selective marker. This proves that the genetic factor for gentamicin resistance is present in the pheromone responsive plasmid. Among these twelve transaconjugants, seven isolates and one isolate were high biofilm formers on addition of E. faecalis FA2-2 and prior to its addition respectively. Out of the total 25 isolates, eight transconjugants for gentamicin resistance could turn to high biofilm formers on addition of the pheromone producing strain. All the isolates were resistant to more than two antibiotics tested. All the isolates were sensitive to vancomycin. The results indicate the significance of this nosocomial pathogen in biofilm formation and the role of pheromone responding clinical isolates of E. faecalis in spread of multidrug resistance genes.

  20. Pheromone killing of multidrug-resistant Enterococcus faecalis V583 by native commensal strains.

    PubMed

    Gilmore, Michael S; Rauch, Marcus; Ramsey, Matthew M; Himes, Paul R; Varahan, Sriram; Manson, Janet M; Lebreton, Francois; Hancock, Lynn Ernest

    2015-06-09

    Multidrug-resistant Enterococcus faecalis possess numerous mobile elements that encode virulence and antibiotic resistance traits as well as new metabolic pathways, often constituting over one-quarter of the genome. It was of interest to determine how this large accretion of mobile elements affects competitive growth in the gastrointestinal (GI) tract consortium. We unexpectedly observed that the prototype clinical isolate strain V583 was actively killed by GI tract flora, whereas commensal enterococci flourished. It was found that killing of V583 resulted from lethal cross-talk between accumulated mobile elements and that this cross-talk was induced by a heptapeptide pheromone produced by native E. faecalis present in the fecal consortium. These results highlight two important aspects of the evolution of multidrug-resistant enterococci: (i) the accretion of mobile elements in E. faecalis V583 renders it incompatible with commensal strains, and (ii) because of this incompatibility, multidrug-resistant strains sharing features found in V583 cannot coexist with commensal strains. The accumulation of mobile elements in hospital isolates of enterococci can include those that are inherently incompatible with native flora, highlighting the importance of maintaining commensal populations as means of preventing colonization and subsequent infection by multidrug-resistant strains.

  1. Biochemical and Genetic Characterization of the Enterococcus faecalis Oxaloacetate Decarboxylase Complex

    PubMed Central

    Repizo, Guillermo D.; Blancato, Víctor S.; Mortera, Pablo; Lolkema, Juke S.

    2013-01-01

    Enterococcus faecalis encodes a biotin-dependent oxaloacetate decarboxylase (OAD), which is constituted by four subunits: E. faecalis carboxyltransferase subunit OadA (termed Ef-A), membrane pump Ef-B, biotin acceptor protein Ef-D, and the novel subunit Ef-H. Our results show that in E. faecalis, subunits Ef-A, Ef-D, and Ef-H form a cytoplasmic soluble complex (termed Ef-AHD) which is also associated with the membrane. In order to characterize the role of the novel Ef-H subunit, coexpression of oad genes was performed in Escherichia coli, showing that this subunit is vital for Ef-A and Ef-D interaction. Diminished growth of the oadA and oadD single deletion mutants in citrate-supplemented medium indicated that the activity of the complex is essential for citrate utilization. Remarkably, the oadB-deficient strain was still capable of growing to wild-type levels but with a delay during the citrate-consuming phase, suggesting that the soluble Ef-AHD complex is functional in E. faecalis. These results suggest that the Ef-AHD complex is active in its soluble form, and that it is capable of interacting in a dynamic way with the membrane-bound Ef-B subunit to achieve its maximal alkalinization capacity during citrate fermentation. PMID:23435880

  2. Enterococcus faecalis causing delayed spondylodiscitis in a case with retained intraspinal bullet

    PubMed Central

    Aiyer, Siddharth N.; Kanna, Rishi; Reddy, Srikanth; Rajasekaran, Shanmuganathan

    2016-01-01

    Delayed presentations have been reported following gunshot wounds (GSW) with retained intraspinal bullets due to migration of projectile or lead intoxication. We report on the rare occurrence of delayed pyogenic spondylodiscitis and neurological dysfunction following injury from low velocity GSW to the spine with a retained projectile. A 55-year-old male presented 4 months following GSW to the abdomen which resulted in colonic injury and L5 fracture. The patient was treated initially with ileo-transverse anastomosis, antibiotics, without retrieval of the bullet. He developed low back pain, claudication 4 months following GSW and investigations suggested a pyogenic spondylodiscitis at L5–S1. The patient was treated with surgical debridement of infective focus and stabilisation with definitive fusion being performed after an interval of 14 days. The biopsy of the lesion confirmed findings of spondylodiscitis and the culture isolated Enterococcus faecalis species. The patient was treated with antibiotics as per sensitivity and made an uneventful recovery over 4 weeks. The follow-up radiographs showed satisfactory healing at final follow up of 24 months. GSW with colonic perforation have higher incidence of infective complications however majority to these occur in the early postoperative period. This case report demonstrates the possibility of late onset presentation due to spinal infection occurring following colonic perforation with retained intraspinal bullet. PMID:28097252

  3. New Insights into the Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus Host Interaction Mechanisms

    PubMed Central

    Romero-Hernández, Beatriz; Conde-Moreno, Elisa; Kwak, Young-Keun; Zamora, Javier; Colque-Navarro, Patricia; Möllby, Roland; Ruiz-Garbajosa, Patricia; Cantón, Rafael; García-Bermejo, Laura; del Campo, Rosa

    2016-01-01

    Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus) were classically clustered into the Lancefield Group D streptococci and despite their taxonomic reclassification still share a similar genetic content and environment. Both species are considered as opportunistic pathogens. E. faecium is often associated with nosocomial bacteraemia, and S. gallolyticus is sporadically found in endocarditis of colorectal cancer patients. In both cases, the source of infection is commonly endogenous with a translocation process that launches through the intestinal barrier. To get new insights into the pathological processes preceding infection development of both organisms, we used an in vitro model with Caco-2 cells to study and compare the adhesion, invasion and translocation inherent abilities of 6 E. faecium and 4 S. gallolyticus well-characterized isolates. Additionally, biofilm formation on polystyrene, collagen I and IV was also explored. Overall results showed that E. faecium translocated more efficiently than S. gallolyticus, inducing a destabilization of the intestinal monolayer. Isolates Efm106, Efm121 and Efm113 (p < .001 compared to Ef222) exhibited the higher translocation ability and were able to adhere 2–3 times higher than S. gallolyticus isolates. Both species preferred the collagen IV coated surfaces to form biofilm but the S. gallolyticus structures were more compact (p = .01). These results may support a relationship between biofilm formation and vegetation establishment in S. gallolyticus endocarditis, whereas the high translocation ability of E. faecium high-risk clones might partially explain the increasing number of bacteraemia. PMID:27463203

  4. Inhibitory Effect of Enterococcus faecium WB2000 on Volatile Sulfur Compound Production by Porphyromonas gingivalis

    PubMed Central

    Higuchi, Takuya; Nakajima, Masato; Fujimoto, Akie; Hanioka, Takashi; Hirofuji, Takao

    2016-01-01

    Volatile sulfur compounds (VSCs) produced by oral anaerobes are the major compounds responsible for oral malodor. Enterococcus faecium WB2000 is recognized as an antiplaque probiotic bacterium. In this study, the effect of E. faecium WB2000 on VSC production by Porphyromonas gingivalis was evaluated, and the mechanism of inhibition of oral malodor was investigated. P. gingivalis ATCC 33277 was cultured in the presence of four lactic acid bacteria, including E. faecium WB2000. Subsequently, P. gingivalis ATCC 33277, W50, W83, and two clinical isolates were cultured in the presence or absence of E. faecium WB2000, and the emission of VSCs from spent culture medium was measured by gas chromatography. The number of P. gingivalis ATCC 33277 in mixed culture with E. faecium WB2000 decreased at 6 h, and the rate of decrease was higher than that in mixed cultures with the other lactic acid bacteria. The numbers of five P. gingivalis strains decreased at similar rates in mixed culture with E. faecium WB2000. The concentration of methyl mercaptan was lower in spent culture medium from P. gingivalis and E. faecium WB2000 cultures compared with that from P. gingivalis alone. Therefore, E. faecium WB2000 may reduce oral malodor by inhibiting the growth of P. gingivalis and neutralizing methyl mercaptan. PMID:27799940

  5. Antimicrobial resistance in Enterococcus spp. isolated from environmental samples in an area of intensive poultry production.

    PubMed

    Furtula, Vesna; Jackson, Charlene R; Farrell, Erin Gwenn; Barrett, John B; Hiott, Lari M; Chambers, Patricia A

    2013-03-12

    Enterococcus spp. from two poultry farms and proximate surface and ground water sites in an area of intensive poultry production were tested for resistance to 16 clinical antibiotics. Resistance patterns were compared to assess trends and possible correlations for specific antimicrobials and levels of resistance. Enterococci were detected at all 12 surface water sites and three of 28 ground water sites. Resistance to lincomycin, tetracycline, penicillin and ciprofloxacin in poultry litter isolates was high (80.3%, 65.3%, 61.1% and 49.6%, respectively). Resistance in the surface water to the same antibiotics was 87.1%, 24.1%, 7.6% and 12.9%, respectively. Overall, 86% of litter isolates, 58% of surface water isolates and 100% of ground water isolates were resistant to more than one antibiotic. Fifty-four different resistance patterns were recognised in isolates obtained from litter and environmental samples and several E. faecium and E. faecalis isolates from litter and environment samples shared the same resistance pattern. Multiple antibiotic resistant (MAR) indices calculated to assess health risks due to the presence of resistant enterococci suggested an increased presence of antibiotics in surface water, likely from poultry sources as no other wastewater contributions in the area were documented.

  6. Glyphosate suppresses the antagonistic effect of Enterococcus spp. on Clostridium botulinum.

    PubMed

    Krüger, Monika; Shehata, Awad Ali; Schrödl, Wieland; Rodloff, Arne

    2013-04-01

    During the last 10-15 years, an increase of Clostridium botulinum associated diseases in cattle has been observed in Germany. The reason for this development is currently unknown. The normal intestinal microflora is a critical factor in preventing intestinal colonisation by C. botulinum as shown in the mouse model of infant botulism. Numerous bacteria in the gastro-intestinal tract (GIT) produce bacteriocines directed against C. botulinum and other pathogens: Lactic acid producing bacteria (LAB) such as lactobacilli, lactococci and enterococci, generate bacteriocines that are effective against Clostridium spp. A reduction of LAB in the GIT microbiota by ingestion of strong biocides like glyphosate could be an explanation for the observed increase in levels of C. botulinum associated diseases. In the present paper, we report on the toxicity of glyphosate to the most prevalent Enterococcus spp. in the GIT. Ingestion of this herbicide could be a significant predisposing factor that is associated with the increase in C. botulinum mediated diseases in cattle.

  7. Increased Enterococcus faecalis infection is associated with clinically active Crohn disease

    PubMed Central

    Zhou, Youlian; Chen, Huiting; He, Hanchang; Du, Yanlei; Hu, Jiaqi; Li, Yingfei; Li, Yuyuan; Zhou, Yongjian; Wang, Hong; Chen, Ye; Nie, Yuqiang

    2016-01-01

    Abstract This study was performed to investigate the relationship between the abundance of pathogenic gut microbes in Chinese patients with inflammatory bowel disease (IBD) and disease severity. We collected clinical data and fecal samples from 47 therapy-naive Chinese patients with ulcerative colitis (UC), 67 patients with Crohn disease (CD), and 48 healthy volunteers. Bacteria levels of Fusobacterium species (spp), enterotoxigenic Bacteroides fragilis (B fragilis), enteropathogenic Escherichia coli (E coli), and Enterococcus faecalis (E faecalis) were assessed by quantitative real-time PCR (qRT-PCR). Spearman correlation coefficients were calculated to test associations between bacterial content and clinical parameters. Compared to healthy controls, the levels of both Fusobacterium spp and E faecalis were significantly increased in the feces of patients with IBD (P < 0.01). B fragilis levels were higher (P < 0.05) and E faecalis levels lower (P < 0.05) in patients with CD compared to those with UC. Increased E faecalis colonization in CD associated positively with disease activity (P = 0.015), Crohn disease activity index (CDAI; R = 0.3118, P = 0.0108), and fecal calprotectin (P = 0.016). E faecalis and Fusobacterium spp are significantly enriched in patients with IBD, and increased E faecalis infection is associated with clinically active CD. PMID:27684872

  8. Application of ozone disinfection to remove Enterococcus seriolicida, Pasteurella piscicida, and Vibrio anguillarum from seawater.

    PubMed Central

    Sugita, H; Asai, T; Hayashi, K; Mitsuya, T; Amanuma, K; Maruyama, C; Deguchi, Y

    1992-01-01

    Survival of bacterial fish pathogens, including Enterococcus seriolicida, Vibrio anguillarum, and Pasteurella piscicida, in ozonated seawater was determined in a batch system. Bacterial counts of all fish pathogens decreased at more than 0.040 to 0.060 mg of total residual oxidants (TROs) per liter, whereas no decrease in viable counts was observed at less than 0.018 to 0.028 mg of TROs per liter. The 99% inactivation point was achieved at concentrations of 0.111 mg/liter for E. seriolicida, 0.063 mg/liter for P. piscicida, and 0.064 mg/liter for V. anguillarum within 1 min. Moreover, the mean 99 and 99.9% killing concentration-contact time (C.t) products were 0.123 and 0.186 mg.min/liter for E. seriolicida, 0.056 and 0.084 mg.min/liter for P. piscicida, and 0.081 and 0.123 mg.min/liter for V. anguillarum, respectively. However, the mean 99 and 99.9% C.t products for the mixed population in coastal seawater were 0.200 and 0.621 mg.min/liter. These results strongly suggest that ozone treatment at more than 1.0 mg of TROs per liter for several minutes is able to disinfect seawater for mariculture efficiently. PMID:1476447

  9. Eradication of Intracanal Enterococcus Faecalis Biofilm by Passive Ultrasonic Irrigation and RinsEndo System

    PubMed Central

    Toljan, Ivana; Bago, Ivona; Anić, Ivica

    2016-01-01

    Aim The aim of the study was to compare the antimicrobial efficacy of three irrigation techniques after the use of standardized volume of NaOCl and with standardized time and irrigation. Methodology Forty-eight single rooted teeth were inoculated with an Enterococcus faecalis suspension for 24 h. The remaining six canals served as negative controls. The 36 root canals were randomly distributed into three experimental groups; group 1, conventional syringe irrigation; group 2, automated-dynamic irrigation (RinsEndo); group 3, passive ultrasonic irrigation (PUI). In the first protocol, the standardized volume of 3% NaOCl (20 mL) was used and in the second protocol, and standardized irrigation time (45 seconds) was used. Samples from root canals were cultured and the colony-forming units (CFUs) were counted. Results When the volume of the irrigant was standardized, RinsEndo was more effective than PUI (p<0.01). When the irrigation time was standardized, there were no significant differences between any irrigation techniques (p>0.05). The RinsEndo group had the highest percentage of minimal counts of E. faecalis CFUs. Conclusions RinsEndo was more effective than PUI only when the volume of the irrigant was standardized. However, the RinsEndo provided higher bacterial reduction in both protocols when using the least amount of the irrigant and providing longer contact time. PMID:27688422

  10. Adherence and intracellular survival within human macrophages of Enterococcus faecalis isolates from coastal marine sediment.

    PubMed

    Sabatino, Raffaella; Di Cesare, Andrea; Pasquaroli, Sonia; Vignaroli, Carla; Citterio, Barbara; Amiri, Mehdi; Rossi, Luigia; Magnani, Mauro; Mauro, Alessandro; Biavasco, Francesca

    2015-09-01

    Enterococcus faecalis is part of the human intestinal microbiota and an important nosocomial pathogen. It can be found in the marine environment, where it is also employed as a fecal indicator. To assess the pathogenic potential of marine E. faecalis, four strains isolated from marine sediment were analyzed for their ability to survive in human macrophages. Escherichia coli DH5α was used as a negative control. The number of adherent and intracellular bacteria was determined 2.5 h after the infection (T0) and after further 24h (T24) by CFU and qPCR counts. At T24 adherent and intracellular enterococcal CFU counts were increased for all strains, the increment in intracellular bacteria being particularly marked. No CFU of E. coli DH5α were detected. In contrast, qPCR counts of intracellular enterococcal and E. coli bacteria were similar at both time points. These findings suggest that whereas E. coli was killed within macrophages (no CFU, positive qPCR), the E. faecalis isolates not only escaped killing, but actually multiplied, as demonstrated by the increase in the viable cell population. These findings support earlier data by our group, further documenting that marine sediment can be a reservoir of pathogenic enterococci.

  11. Galangin expresses bactericidal activity against multiple-resistant bacteria: MRSA, Enterococcus spp. and Pseudomonas aeruginosa.

    PubMed

    Pepeljnjak, Stjepan; Kosalec, Ivan

    2004-11-01

    The antimicrobial activity of three propolis ethanol extracts (EEP) was examined for various Gram-negative and Gram-positive bacterial species, including multiple-resistant Staphylococcus aureus, Enterococcus spp. and Pseudomonas aeruginosa strains. EEP had a good bactericidal activity against Gram-positive species, and all multiple-resistant bacterial strains tested were sensitive to EEP. Minimal inhibitory concentrations (MICs) were lower in samples of higher flavonoid content (from 0.65 to 7.81 mg mL(-1)), indicating the influence of the concentration of some potent bactericidal compound(s) in propolis or synergism among some bactericidal compounds. Antimicrobial-guided separation of flavonoid aglycones (bioassay in situ on thin-layer chromatogram) showed that galangin (3,5,7-trihydroxyflavone) is one compound in EEP with bactericidal activity. Galangin was isolated by preparative chromatography. After determining the quantity present, the MIC against multiple-resistant bacteria was determined. The MIC of galangin against multiple-resistant bacterial strains was significantly lower (from 0.16 to 0.44 mg mL(-1), p < 0.05) than that of EEP. The bactericidal activity of galangin against P. aeruginosa strains was present at 0.17+/-0.05 mg mL(-1).

  12. Heat-Killed Enterococcus faecalis EF-2001 Ameliorates Atopic Dermatitis in a Murine Model

    PubMed Central

    Choi, Eun-Ju; Iwasa, Masahiro; Han, Kwon-Il; Kim, Wan-Jae; Tang, Yujiao; Hwang, Young Joung; Chae, Jeong Ryong; Han, Weon Cheol; Shin, Yu-Su; Kim, Eun-Kyung

    2016-01-01

    Recent reports have shown the immunomodulatory effect of heat-killed lactic acid bacteria. Atopic dermatitis (AD) is an allergic skin disease, caused by immune dysregulation among other factors. The aim of this study was to assess the effect of heat-killed Enterococcus faecalis EF-2001 (EF-2001) on AD. We established an in vivo AD model by repeated local exposure of Dermatophagoides farinae extract (DFE; house dust mite extract) and 2,4-dinitrochlorobenzene (DNCB) to the ears of mice. After oral administration of EF-2001 for four weeks, the epidermal and dermal ear thickness, mast cell infiltration, and serum immunoglobulin levels were measured. In addition, the gene expression levels of pathogenic cytokines in the ears, lymph nodes, and splenocytes were assayed. EF-2001 attenuated AD symptoms based on the ear thickness, histopathological analysis, and serum immunoglobulin levels. Moreover, EF-2001 decreased the DFE/DNCB-induced expression of various pathogenic cytokines in the ears, lymph nodes, and splenocytes. These results suggest that EF-2001 has therapeutic potential in the treatment of AD owing to its immunomodulatory effects. PMID:26959058

  13. Indole production provides limited benefit to Escherichia coli during co-culture with Enterococcus faecalis.

    PubMed

    Pringle, Shelly L; Palmer, Kelli L; McLean, Robert J C

    2017-01-01

    Escherichia coli lives in the gastrointestinal tract and elsewhere, where it coexists within a mixed population. Indole production enables E. coli to grow with other gram-negative bacteria as indole inhibits N-acyl-homoserine lactone (AHL) quorum regulation. We investigated whether E. coli indole production enhanced competition with gram-positive Enterococcus faecalis, wherein quorum signaling is mediated by small peptides. During planktonic co-culture with E. faecalis, the fitness and population density of E. coli tnaA mutants (unable to produce indole) equaled or surpassed that of E. coli wt. During biofilm growth, the fitness of both populations of E. coli stabilized around 100 %, whereas the fitness of E. faecalis declined over time to 85-90 %, suggesting that biofilm and planktonic populations have different competition strategies. Media supplementation with indole removed the competitive advantage of E. coli tnaA in planktonic populations but enhanced it in biofilm populations. E. coli wt and tnaA showed similar growth in Luria-Bertani (LB) broth. However, E. coli growth was inhibited in the presence of filter-sterilized spent LB from E. faecalis, with inhibition being enhanced by indole. Similarly, there was also an inhibition of E. faecalis growth by proteinaceous components (likely bacteriocins) from spent culture media from both E. coli strains. We conclude that E. coli indole production is not a universal competition strategy, but rather works against gram-negative, AHL-producing bacteria.

  14. The Prophylactic Effect of Probiotic Enterococcus lactis IW5 against Different Human Cancer Cells

    PubMed Central

    Nami, Yousef; Haghshenas, Babak; Haghshenas, Minoo; Abdullah, Norhafizah; Yari Khosroushahi, Ahmad

    2015-01-01

    Enterococcus lactis IW5 was obtained from human gut and the potential probiotic characteristics of this organism were then evaluated. Results showed that this strain was highly resistant to low pH and high bile salt and adhered strongly to Caco-2 human epithelial colorectal cell lines. The supernatant of E. lactis IW5 strongly inhibited the growth of several pathogenic bacteria and decreased the viability of different cancer cells, such as HeLa, MCF-7, AGS, HT-29, and Caco-2. Conversely, E. lactis IW5 did not inhibit the viability of normal FHs-74 cells. This strain did not generate toxic enzymes, including β-glucosidase, β-glucuronidase, and N-acetyl-β-glucosaminidase and was highly susceptible to ampicillin, gentamycin, penicillin, vancomycin, clindamycin, sulfamethoxazol, and chloramphenicol but resistant to erythromycin and tetracyclin. This study provided evidence for the effect of E. lactis IW5 on cancer cells. Therefore, E. lactis IW5, as a bioactive therapeutics, should be subjected to other relevant tests to verify the therapeutic suitability of this strain for clinical applications. PMID:26635778

  15. Heat-Killed Enterococcus faecalis EF-2001 Ameliorates Atopic Dermatitis in a Murine Model.

    PubMed

    Choi, Eun-Ju; Iwasa, Masahiro; Han, Kwon-Il; Kim, Wan-Jae; Tang, Yujiao; Hwang, Young Joung; Chae, Jeong Ryong; Han, Weon Cheol; Shin, Yu-Su; Kim, Eun-Kyung

    2016-03-05

    Recent reports have shown the immunomodulatory effect of heat-killed lactic acid bacteria. Atopic dermatitis (AD) is an allergic skin disease, caused by immune dysregulation among other factors. The aim of this study was to assess the effect of heat-killed Enterococcus faecalis EF-2001 (EF-2001) on AD. We established an in vivo AD model by repeated local exposure of Dermatophagoides farinae extract (DFE; house dust mite extract) and 2,4-dinitrochlorobenzene (DNCB) to the ears of mice. After oral administration of EF-2001 for four weeks, the epidermal and dermal ear thickness, mast cell infiltration, and serum immunoglobulin levels were measured. In addition, the gene expression levels of pathogenic cytokines in the ears, lymph nodes, and splenocytes were assayed. EF-2001 attenuated AD symptoms based on the ear thickness, histopathological analysis, and serum immunoglobulin levels. Moreover, EF-2001 decreased the DFE/DNCB-induced expression of various pathogenic cytokines in the ears, lymph nodes, and splenocytes. These results suggest that EF-2001 has therapeutic potential in the treatment of AD owing to its immunomodulatory effects.

  16. Study Comparing the Effectiveness of Chlorhexidine, Calcium Hydroxide and Linezolid Based Medicaments Against Enterococcus Faecalis

    PubMed Central

    Pavaskar, Rajdeep; Chalakkal, Paul; Krishnan, Ramesh; Sirikonda, Saritha; Vasepalli, Madhu; Venkataramana, Pammi

    2014-01-01

    Purpose: This study evaluated the efficacy of 2% chlorhexidine (CX), calcium hydroxide (CH), Vitapex® (VP), linezolid (LZ), a combination of LZ with CH (LC) against Enterococcus faecalis (EF). Study Design: EF strains were mixed with peptone water and the turbidity was adjusted to the McFarland’s turbidity standard tube No: 0.5. The inoculum obtained was used to make lawn cultures on the agar plates. A total of 30 agar plates were prepared, such that each plate had five wells containing the five medicaments. The plates were incubated and evaluated for zones of inhibition after intervals of 24 hours and 72 hours. The results were statistically evaluated by paired t-test, ANOVA and Post-hoc analysis using Tukey’s HSD. Results: The difference between values of the zones of inhibition around various medicaments after 24 hours and 72 hours was found to be statistically significant. A comparison between the five groups after 24 hours or 72 hours showed that each group differed significantly from the rest of the groups. Conclusions: LC had the greatest effectiveness against EF, followed by LZ, CX, VP and CH. PMID:24783147

  17. New Insights into the Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus Host Interaction Mechanisms.

    PubMed

    Sánchez-Díaz, Ana María; Romero-Hernández, Beatriz; Conde-Moreno, Elisa; Kwak, Young-Keun; Zamora, Javier; Colque-Navarro, Patricia; Möllby, Roland; Ruiz-Garbajosa, Patricia; Cantón, Rafael; García-Bermejo, Laura; Del Campo, Rosa

    2016-01-01

    Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus) were classically clustered into the Lancefield Group D streptococci and despite their taxonomic reclassification still share a similar genetic content and environment. Both species are considered as opportunistic pathogens. E. faecium is often associated with nosocomial bacteraemia, and S. gallolyticus is sporadically found in endocarditis of colorectal cancer patients. In both cases, the source of infection is commonly endogenous with a translocation process that launches through the intestinal barrier. To get new insights into the pathological processes preceding infection development of both organisms, we used an in vitro model with Caco-2 cells to study and compare the adhesion, invasion and translocation inherent abilities of 6 E. faecium and 4 S. gallolyticus well-characterized isolates. Additionally, biofilm formation on polystyrene, collagen I and IV was also explored. Overall results showed that E. faecium translocated more efficiently than S. gallolyticus, inducing a destabilization of the intestinal monolayer. Isolates Efm106, Efm121 and Efm113 (p < .001 compared to Ef222) exhibited the higher translocation ability and were able to adhere 2-3 times higher than S. gallolyticus isolates. Both species preferred the collagen IV coated surfaces to form biofilm but the S. gallolyticus structures were more compact (p = .01). These results may support a relationship between biofilm formation and vegetation establishment in S. gallolyticus endocarditis, whereas the high translocation ability of E. faecium high-risk clones might partially explain the increasing number of bacteraemia.

  18. Biological changes of Enterococcus faecalis in the viable but nonculturable state.

    PubMed

    E, J; Jiang, Y T; Yan, P F; Liang, J P

    2015-11-23

    Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.

  19. Antibiotic susceptibility, antibacterial activity and characterisation of Enterococcus faecium strains isolated from breast milk

    PubMed Central

    Kıvanç, Sertaç Argun; Kıvanç, Merih; Yiğit, Tülay

    2016-01-01

    Enterococci, which have useful biotechnological applications, produce bacteriocins, including those that exert anti-Listerial activity. The present study aimed to determine the antibiotic susceptibility patterns and antimicrobial activity of Enterococcus faecium strains isolated from human breast milk. The strains were identified using carbohydrate fermentation tests and ribotyping. Subsequently, the antibacterial activity of the isolates was investigated, and the quantities of lactic acid and hydrogen peroxide produced, and the proteolytic activity of E. faecium, were determined. In addition, biofilm formation by E. faecium strains was assessed. E. faecium strains exhibited antimicrobial activity against food-borne and clinical bacterial isolates. Furthermore, following 24 h incubation, the tested strains exhibited resistance to a pH range of 2.0–9.5 and tolerance of bile acid, lysozyme activity and phenol. Supernatants of the E. faecium TM13, TM15, TM17 and TM18 strains were shown to be effective against Listeria monocytogenes, and were also resistant to heat. Further studies are required in order to determine whether certain strains of E. faecium may be used for the development of novel antibacterial agents. PMID:27602088

  20. Involvement of Enterococcus faecalis Small RNAs in Stress Response and Virulence

    PubMed Central

    Michaux, Charlotte; Hartke, Axel; Martini, Cecilia; Reiss, Swantje; Albrecht, Dirk; Budin-Verneuil, Aurélie; Sanguinetti, Maurizio; Engelmann, Susanne; Hain, Torsten; Verneuil, Nicolas

    2014-01-01

    Candidate small RNAs (sRNAs) have recently been identified in Enterococcus faecalis, a Gram-positive opportunistic pathogen, and six of these candidate sRNAs with unknown functions were selected for a functional study. Deletion mutants and complemented strains were constructed, and their virulence was tested. We were unable to obtain the ef0869-0870 mutant, likely due to an essential role, and the ef0820-0821 sRNA seemed not to be involved in virulence. In contrast, the mutant lacking ef0408-0409 sRNA, homologous to the RNAII component of the toxin-antitoxin system, appeared more virulent and more able to colonize mouse organs. The three other mutants showed reduced virulence. In addition, we checked the responses of these mutant strains to several stresses encountered in the gastrointestinal tract or during the infection process. In parallel, the activities of the sRNA promoters were measured using transcriptional fusion constructions. To attempt to identify the regulons of these candidate sRNAs, proteomics profiles of the mutant strains were compared with that of the wild type. This showed that the selected sRNAs controlled the expression of proteins involved in diverse cellular processes and the stress response. The combined data highlight the roles of certain candidate sRNAs in the adaptation of E. faecalis to environmental changes and in the complex transition process from a commensal to a pathogen. PMID:24914223