Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Enterococcus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1998

RP59500 (Quinupristin/dalfopristin): three case reports of its use in infection due to Enterococcus faecium.

We describe three cases of Enterococcus faecium sepsis arising in immunocompromised patients, severely ill with other conditions, who were treated with the new injectable streptogramin RP59500. There are still few reports of clinical experience with this drug. All had bacteriological resolution, with one patient recovering fully. Although two of the three patients died, this was due to underlying disease in one case and a gram-negative superinfection in another. Quinupristin/dalfopristin therapy was not associated with significant adverse effects in any of the patients.

Adolescent↗
PubMed2002

Crystallization and preliminary X-ray crystallographic analysis of Ace: a collagen-binding MSCRAMM from Enterococcus faecalis.

Ace is a collagen-binding bacterial cell surface adhesin from Enterococcus faecalis. The collagen-binding domain of Ace (termed Ace40) and its truncated form Ace19 have been crystallized by the vapor-diffusion hanging-drop method. Ace19 was crystallized in two different crystal forms. A complete 1.65 A data set has been collected on the orthorhombic crystal form with unit cell parameters a=38.43 b=48.91 and c=83.73 A. Ace40 was crystallized in the trigonal space group P3(1)21 or P3(2)21 with unit cell parameters a=b=80.24, c=105.91 A; alpha=beta=90 and gamma=120 degrees. A full set of X-ray diffraction data was collected to 2.5 A. Three heavy atom derivative data sets have been successfully obtained for Ace19 crystals and structural analysis is in progress.

Adhesins, Bacterial↗
PubMed2000

Prevalence of vancomycin-resistant Enterococcus faecium (VREF) in pig faeces from slaughterhouses in Spain.

A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8microg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256microg/ml (62 strains) and 512microg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.

Abattoirs↗
PubMed1997

Avoparcin used as a growth promoter is associated with the occurrence of vancomycin-resistant Enterococcus faecium on Danish poultry and pig farms.

We determined the association between the use of the glycopeptide antibiotic avoparcin as a growth promoter and the occurrence of Enterococcus faecium (VREF) with high-level resistance to vancomycin (MIC > or = 64 micrograms ml-1) on poultry and pig farms. The investigations were conducted as retrospective cohort studies, where groups of farms exposed or not exposed to avoparcin between September 1994 and April 1995 were compared. In poultry, the association between the use of avoparcin and the occurrence of VREF was confounded by the use of broad-spectrum antibiotics, and the adjusted relative risk was 2.9 (1.4-5.9). In pigs, the association had a similar magnitude with a non-adjusted relative risk of 3.3 (0.9-12.3). The similar findings in the two studies provide evidence in favour of a causal association between the use of avoparcin and the occurrence of VREF on farms, and suggest that food animals constitute a potential reservoir of infection for VREF in humans.

Animals↗
PubMed2002

Identification of Enterococcus spp. based on specific hybridisation with 16S rDNA probes.

The conventional methods for routine enterococci species identification are usually based on phenotypic characteristics. However, in recent years, some studies have defined specific probes based on both 16S and 23S rRNA genes for the identification of some Enterococcus spp. A set of probes based on the 16S rRNA gene has been developed in order to evaluate the usefulness of a six-step biochemical key for species level identification of enterococci. Probe specificity has been evaluated with type collection and environmental strains by dot blot hybridisation. A high correlation was obtained between biochemical key and hybridisation identifications. This set of probes provides a confirmative method for phenotypic species identification.

Animals↗
PubMed2003

Evaluation of a novel method based on amplification of DNA fragments surrounding rare restriction sites (ADSRRS fingerprinting) for typing strains of vancomycin-resistant Enterococcus faecium.

In the search for an effective DNA-typing technique for use in hospital epidemiology, the performance and convenience of a novel assay based on the fingerprinting of bacterial genomes by amplification of DNA fragments surrounding rare restriction sites (ADSRRS fingerprinting) was tested. A large number of vancomycin-resistant Enterococcus faecium (VREM) isolates from haematological ward patients of the Clinical Hospital in Gdańsk were examined. We found that ADSRRS fingerprinting analysis is a rapid method that offers good discriminatory power. The method demonstrated also excellent reproducibility. The usefulness of the ADSRRS fingerprinting method for molecular typing was compared with pulsed field gel electrophoresis (PFGE) method, which is currently considered the gold standard for molecular typing of isolates recovered from patients and the environment in the course of investigation and control of nosocomial outbreaks. Clustering of ADSRRS fingerprinting data matched pulsed field gel electrophoresis data. The features of ADSRRS fingerprinting technique is discussed in comparison with conventional methods. Data presented here demonstrate the complexity of the epidemiological situation concerning VREM that may occur in a single medical ward.

Bacterial Proteins↗
PubMed2003

Comparative studies on the activity of basil--an essential oil from Ocimum basilicum L.--against multidrug resistant clinical isolates of the genera Staphylococcus, Enterococcus and Pseudomonas by using different test methods.

The essential oil basil is obtained from the aerial parts of Ocimum basilicum L. After gas chromatographic separation, the following components were identified: linalol (54.95%), methylchavikol (11.98%), methylcinnamat (7.24%) and linolen (0.14%). The activity of basil against multidrug resistant clinical isolates from the genera Staphylococcus, Enterococcus and Pseudomonas has been studied. For this purpose, standard and modified broth macrodilution methods were used and time kill kinetic of basil was studied. The minimum inhibitory concentrations (MICs) were reported between 0.0030% and 0.0007% (v/v). These concentrations were compared with the inhibitory concentrations (ICs) and the logs of the bacterial counts reduction both obtained by basil diluted in 1% Tween (Tw) 80, saline test solution (STS) and spiritus vini (Sv) 95 degrees instead in a broth. The data, obtained after application of different methods of investigation and validated with membrane filtration, showed a strong inhibitory effect of basil on the test bacteria. The chosen bacteria are widespread and pose serious therapeutic difficulties because of their high level of resistance. For this reason, the results obtained were considered encouraging.

Anti-Bacterial Agents↗
PubMed2003

A simple method for semi-preparative-scale production and recovery of enterocin AS-48 derived from Enterococcus faecalis subsp. liquefaciens A-48-32.

Production of enterocin AS-48 by Enterococcus faecalis A-48-32 was compared between standard and high-cell density batch fermentations. In high-cell density cultures, bacteriocin production was 2.47-fold higher, provided that the pH was controlled during the fermentation. A two-step procedure for recovery of milligram quantities of purified bacteriocin was developed, based on adsorption of the bacteriocin on Carboxymethyl Sephadex CM-25 followed by reversed-phase chromatography on a semi-preparative column. The purified bacteriocin was active on all the Gram-positive bacteria tested (for example, species of Bacillus, Paenibacillus, Staphylococcus, and Listeria). Strains E. coli U-9, E. coli CECT 102, E. coli CECT 104, E. coli CECT 432, E. coli CECT 543, E. coli CECT 877 and Shigella sonnei CECT 542 were sensitive, while seven other E. coli strains as well as Salmonella choleraesuis CECT 722, S. choleraesuis CECT 916, Enterobacter cloacae CECT 194 and Aeromonas hydrophila CECT 398 were resistant.

Bacteriocins↗
PubMed2000

Characterization and analysis of a new gene involved in glucose starvation response in Enterococcus faecalis.

The genome sequence of Enterococcus faecalis, led us to discover that gls24, encoding a general stress protein, seems to be in the second last position of a putative six-gene operon structure. Interestingly, another gene named orf4 located just upstream from gls24 shows strong identity (72%) with this last. To determine the role of the orf4 gene in E. faecalis, we have constructed a mutant strain by homologous recombination. Phenotypic analysis of these cells, reveals that Orf4 is probably involved in cell structure in stationary phase.

Enterococcus faecalis↗
PubMed2000

Cloning, sequencing and characterization of the ccpA gene from Enterococcus faecalis.

Enzymes involved in the metabolism of complex carbon and energy sources are unnecessary under conditions of abundant, readily metabolisable nutrients such as glucose or fructose. The repression of these enzymes by glucose has been termed carbon catabolite repression. Mechanisms involved in the carbon catabolite repression in gram-positive bacteria are known to differ from those of gram-negative bacteria such as Escherichia coli. It appears to be mediated by transcriptional repression, requiring trans-acting CcpA, a member of the LacI-GalR family of bacterial regulatory proteins and a cis-acting consensus sequence, designated cre. Here, we report the cloning and characterisation of the chromosomal ccpA gene from Enterococcus faecalis JH2-2. This gene is predicted to encode a 333 amino acids protein with nearly 75% identity to CcpA of Lactobacillus casei.

Amino Acid Sequence↗
PubMed2000

Survival of a Pseudomonas fluorescens and Enterococcus faecalis aerosol on inert surfaces.

The aim of the work presented here is to study airborne bacteria survival on three inert supports (glass, polyvinyl chloride, and stainless steel). Two Pasteur Institute bacteria were selected: Enterococcus faecalis 10.30.15 and Pseudomonas fluorescens 56.90. We have observed that bacterial aerosol lethality increased proportionally with the relative humidity of the environment, the gram-negative rod appearing more fragile than the cocci. A significant difference in survival rate is measured dependent on the supports tested, the greatest lethality being observed on the PVCs.

Aerosols↗
PubMed2000

Isolation and characterization of Carnobacterium, Lactococcus, and Enterococcus spp. from cooked, modified atmosphere packaged, refrigerated, poultry meat.

The microbiota of commercially produced, cooked and modified atmosphere packaged poultry meat was followed during storage at 3.5 degrees C for up to 7 weeks. The dominant microbiota consisted of Lactococcus raffinolactis (117 isolates), Carnobacterium divergens (61 isolates), Carnobacterium piscicola (11 isolates), Lactococcus garvieae (four isolates), Lactococcus lactis (one isolate) and Enterococcus faecalis (three isolates). All isolates were screened for production of bacteriocins. Only C. piscicola isolates produced an inhibitory substance active against other lactic acid bacteria and against several Listeria spp. Species-specific polymerase chain reaction (PCR) primers were used for the differentiation of Carnobacterium, L. raffinolactis, L. lactis, and L. garvieae strains associated with the modified atmosphere packaged poultry products. No false PCR products were observed with other closely related bacterial species.

Animals↗
PubMed2001

Effect of different complex carbon sources on growth and bacteriocin synthesis of Enterococcus faecium.

Different criteria are followed in order to select bacteria to be used in probiotic and symbiotic supplements. A new parameter to choose strains could be fermentation by intestinal bacteria of some complex carbohydrates because they are prebiotics and promote the development of beneficial microorganisms in the intestinal environment. An Enterococcus faecium strain, isolated from the crop of a free-range chicken, was assayed in order to determine the utilization of commercial sugars and/or crude carbohydrate samples from a sugar mill. The production of antimicrobial substances, under these conditions, was also considered. Ent. faecium CRL1385 grew well in the presence of complex carbohydrates and its ability to produce bacteriocin, active against poultry pathogens such as Ent. hirae, Salmonella pullorum and Listeria monocytogenes, was not significantly modified. These results are promising because the trend today is to employ eubiotic or symbiotic products and their use in the poultry industry could be a natural way to protect the flocks against potential pathogens.

Animals↗
PubMed2001

Effects of pH, temperature and NaCl concentration on the growth kinetics, proteolytic activity and biogenic amine production of Enterococcus faecalis.

In this work, the combined effects of temperature, pH and NaCl concentration on the growth dynamics of Enterococcus faecalis EF37, its proteolytic activity and its production of biogenic amines have been studied. The effects of the selected variables have been analysed using a Central Composite Design. The production of biogenic amines, under the adopted conditions, was found to be mainly dependent on the extent of growth of E. faecalis. Its proteolytic activity was not a limiting factor for the final amine production, because in the system studied (skim milk) an excess of precursors was guaranteed. Quantitatively, the most important biogenic amine produced was 2-phenylethylamine but substantial amounts of tyramine were detected in all the samples. This work confirms that the main biological feature influencing the biogenic amine formation is the extent of growth of microorganisms, like E. faecalis, characterised by decarboxylase activity. In the traditional and artisanal cheeses produced using raw milk, enterococci usually reach levels of 10(7) cells/g. With this perspective, it is important that the presence of biogenic amines due to the activities of these microorganisms is maintained within safe levels, without affecting the positive effects of enterococci on the final organoleptic characteristics of the cheese.

Animals↗
PubMed2001

Biochemical and genetic evidence for production of enterocins A and B by Enterococcus faecium WHE 81.

Enterococcus faecium WHE 81, isolated from cheese, has been reported to produce a bacteriocin called "enterocin 81" [J. Appl. Microbiol. 85 (1998) 521.]. Purification of "enterocin 81" was carried out using ammonium sulfate precipitation, desalting on ODP-90 reverse-phase column, and purification through SP Sepharose HP cation exchange and C2/C18 reverse-phase chromatographies. The antimicrobial was eluted from the C2/C18 column as four individually active fractions, designated A81, B81, C81 and D81. The purification procedure used proved particularly efficient for the bacteriocin in fraction D81, with a yield of 46%, while only 3.8% the bacteriocin in fraction B81 could be collected. MALDI-TOF mass spectrometry of the bacteriocins in fractions B81 and D81 showed respective masses of 4,833.0 and 5,462.2 Da. Amino acid sequencing of the two peptides revealed two class-II bacteriocins whose sequences were similar to those of enterocin A and enterocin B, respectively. Using proper primers, chromosomal fragments of 212 and 216 bp enclosing bacteriocin structural genes were PCR-amplified. Cloning of the amplicons and their sequencing revealed two genes with sequences identical to the structural genes of enterocins A and B, respectively. It was therefore clearly established that E. faecium WHE 81 produces bacteriocins respectively identical to enterocins A and B. Our results, combined with data from previous reports, suggest that the two bacteriocins may be widespread among enterococcal strains and may play an important role in controlling the growth of pathogens and other undesirable bacteria in certain fermented food products.

Amino Acid Sequence↗
PubMed2002

Bacteriocin production by Enterococcus faecium FAIR-E 198 in view of its application as adjunct starter in Greek Feta cheese making.

Bacteriocin production by Enterococcus faecium FAIR-E 198, isolated from Greek Feta cheese, was studied in batch fermentations, under conditions simulating Feta cheese preparation. Maximum enterocin activity and growth rate was obtained in de Man-Rogosa-Sharpe (MRS) broth at 37 degrees C with controlled pH 6.5. The enterocin was produced throughout the growth phase of the microorganism, showing primary metabolite kinetics with a peak activity during the mid-exponential phase. The use of skimmed milk as substrate revealed low enterocin activity. When fermentations were performed in skimmed milk in the presence of rennet, CaCl2, and a mixed starter culture, no enterocin activity was observed, although the examined strain grew well under the above conditions. Finally, when E. faecium FAIR-E 198 was applied as adjunct starter in Feta cheese making, no enterocin activity was detected throughout ripening. Results obtained underline the frequently underestimated finding that in vitro production by novel bacteriocinogenic starter or co-cultures is no guarantee for in situ efficiency. It was concluded that the complex food environment thoroughly interferes with bacteriocin production levels.

Animals↗
PubMed2002

Bacteriocin production by Enterococcus faecium RZS C5 is cell density limited and occurs in the very early growth phase.

Enterocins, bacteriocins produced by enterococci, are gaining interest because of their antilisterial activity. Enterococcus faecium RZS C5, a natural isolate from cheese, produces such a bacteriocin. Generally, bacteriocin production by lactic acid bacteria is a growth-associated process which ceases when cell growth starts to level off. Remarkably, enterocin production by Ent. faecium RZS C5 seems to be limited to the very early growth phase and is switched off at a well-defined cell density of 0.4 g cell dry mass (CDM) l(-1). However, at pH values higher than 6.5, enterocin production displays distinct kinetics. At such pH values, enterocin production is reduced but is maintained until the end of the active growth phase. The relation with cell concentration suggests that enterocin production is part of a severely regulated mechanism. A kinetic model is set up for the description of the early enterocin activity peak. Furthermore, the influence of pH and temperature on the kinetics of growth and bacteriocin production of Ent. faecium RZS C5 was investigated. At pH 6.5, high enterocin activity was obtained in the temperature range 20-35 degrees C. At 35 degrees C, enterocin activity could only be detected between pH 5.5 and 8.0.

Animals↗
PubMed2002

Enterocin 416K1, an antilisterial bacteriocin produced by Enterococcus casseliflavus IM 416K1 isolated from Italian sausages.

Enterococci (118) from Italian sausages were tested for the production of antimicrobial substances. Of these, 7.6% showed antibacterial activity against one or several closely related microorganisms used as indicators. Enterococcus casseliflavus IM 416K1 in particular produced a bacteriocin (Enterocin 416K1) with strong anti-listerial antagonistic activity. The bacteriocin withstood heating at 90 degrees C for 120 min and storage at 4 degrees C for 6 months. The mode of action was identified as bactericidal. The crude activity of Enterocin 416K1 was linked to a molecule with an apparent molecular weight smaller than 5 kDa. Plasmid analysis of E. casseliflavus IM 416K1 revealed the presence of four plasmids with different molecular weights (34, 11, 7 and 3.3 MDa). All the Bac- variants produced by curing experiments showed loss of the single plasmid of 34 MDa. Bacteriocin activity and immunity production may be linked to genes located on that same plasmid.

Animals↗