SEARCH · Search PubMed

Results for “Enterococcus spp.”

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.

SourceResearch connectionFrom yearThrough year

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

PubMed1985

Trends in bacterial susceptibility to antimicrobial agents.

Concern over the development of drug resistance by common pathogens has grown over recent years. In order to discover and describe possible trends at this institution, susceptibility data for 18 organisms and 21 antimicrobial agents for the years 1975 through 1982 at the Veterans Administration Medical Center in Oklahoma City were reviewed. Summaries of susceptibility data for 64 major combinations of drugs and organisms are presented. Two gram-positive organisms (enterococcus group D and Staphylococcus aureus) as well as a gram-negative (Pseudomonas aeruginosa) appear to be decreasing in susceptibility to several drugs. However, some gram-negative bacilli (Proteus, Serratia, and Enterobacter spp. and Klebsiella pneumoniae) showed evidence of markedly increasing susceptibility to certain drugs.

Anti-Bacterial Agents↗

PubMed2000

Incidence and susceptibility of pathogenic bacteria vary between intensive care units within a single hospital: implications for empiric antibiotic strategies.

BACKGROUND: The purpose of this study was to determine whether the incidence of recovery and patterns of antibiotic susceptibility of pathogenic bacteria vary between intensive care units (ICUs) in a single teaching hospital. METHODS: Culture and susceptibility results were collected prospectively for a 3-month period (April through June 1999) in each of the surgical, trauma, and medical ICUs. The number of unique isolates and susceptibility patterns were determined. Susceptibility of isolates among ICUs was compared with chi2. RESULTS: Statistically significant differences between ICUs in susceptibility to various antibiotics were found for Staphylococcus aureus, Enterococcus sp, Acinetobacter sp, Enterobacter sp, Klebsiella sp, and Pseudomonas sp. Notably, vancomycin-resistant Enterococcus was not seen in the medical ICU, whereas it was seen in both the surgical and trauma ICUs. Klebsiella spp resistant to ceftazidime were seen only in the trauma ICU. The aminoglycosides and quinolones had attenuated activity against Pseudomonas sp in the surgical ICU, whereas they remained highly effective in the trauma ICU. Cefazolin had no activity against the Enterobacter sp in either of the surgical ICUs, but was highly effective in the medical ICU. CONCLUSION: Although the microbiologic results of this study should not be extrapolated to other institutions, the principle is of value. There is variability between ICUs in a single large teaching hospital in susceptibility of bacterial pathogens to various antibiotics. This may have implications in the design of empiric antibiotic strategies and the planning of the hospital formulary. Hospital wide or composite ICU antibiograms are inadequate for planning empiric therapy in the ICU.

Antibiotic Prophylaxis↗

PubMed2005

Starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages.

The effectiveness of selected starter cultures and high hydrostatic pressure after ripening was evaluated to improve the safety and quality of slightly fermented sausages. Inhibition of common foodborne pathogens, spoilage bacteria, and biogenic amine content was studied. Random amplification of polymorphic DNA and plasmid profiles were used to monitor the competitiveness of the starter cultures during fermentation and ripening. Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 dominated L. sakei CTC6469 and S. xylosus CTC6169 independently of the product assayed. Starter cultures were able to control the growth of Listeria monocytogenes, Enterobacteriaceae, Enterococcus, and the biogenic amine content. A pH decrease below 5.3 at the seventh day of fermentation was crucial. Salmonella spp. counts decreased significantly during ripening independently of the use of starter culture and product. High hydrostatic pressure treatment was necessary to ensure absence of Salmonella spp. in final products.

Animals↗

PubMed1998

Recent developments in streptogramin research.

The streptogramins are a class of antibiotics remarkable for their antibacterial activity and their unique mechanism of action. These antibiotics are produced naturally, but the therapeutic use of the natural compounds is limited because they do not dissolve in water. New semisynthetic derivatives, in particular the injectable streptogramin quinupristin/dalfopristin, offer promise for treating the rising number of infections that are caused by multiply resistant bacteria. The streptogramins consist of two structurally unrelated compounds, group A and group B. The group A compounds are polyunsaturated macrolactones: the group B compounds are cyclic hexadepsipeptides. Modifications of the group B components have been mainly performed on the 3-hydroxypicolinoyl, the 4-dimethylaminophenylalanine and the 4-oxo pipecolinic residues. Semi-synthesis on this third residue led to the water-soluble derivative quinupristin. Water-soluble group A derivatives were obtained by Michael addition of aminothiols to the dehydroproline ring of pristinamycin IIA. Followed by oxidation of the intermediate sulfide into the sulfone derivatives (i.e., dalfopristin). Water-soluble derivatives (both group A and group B) can now be obtained at the industrial scale. Modified group B compounds are now also being produced by mutasynthesis, via disruption of the papA gene. Mutasynthesis has proved particularly useful for producing PIB, the group B component of the oral streptogramin RPR 106972. The streptogramins inhibit bacterial growth by disrupting the translation of mRNA into protein. Both the group A and group B compounds bind to the peptidyltransferase domain of the bacterial ribosome. The group A compounds interfere with the elongation of the polypeptide chain by preventing the binding of aa-tRNA to the ribosome and the formation of peptide bonds, while the B compounds stimulate the dissociation of the peptidyl-tRNA and may also interfere with the release of the completed polypeptide by blocking its access to the channel through which it normally leaves the ribosome. The synergy between the group A and group B compounds appears to result from an enhanced affinity of the group B compounds for the ribosome. Apparently, the group A compound induces a conformational change such that B compound binds with greater affinity. The natural streptogramins are produced as mixtures of the group A and B compounds, the combination of which is a more potent antibacterial agent than either type of compound alone. Whereas the type A or type B compound alone has, in vitro and in animal models of infection, a moderate bacteriostatic activity, the combination of the two has strong bacteriostatic activity and often bactericidal activity. Minimal inhibitory concentrations of quinupristin/dalfopristin range from 0.20 to 1 mg/l for Streptococcus pneumonae, from 0.25 to 2 mg/l for Staphylococcus aureus and from 0.50 to 4 for Enterococcus faecium, the principal target organisms of this drug. Quinupristin/dalfopristin also has activity against mycoplasmas, Neisseria gonorrhoeae, Haemophilus influenz, Legionella spp. and Moraxella catarrhalis. Bacteria develop resistance to the streptogramms by ribosomal modification, by producing inactivating enzymes, or by causing an efflux of the antibiotic. Dimethylation of an adenine residue in rRNA, a reaction that is catalyzed by a methylase encoded by the erm gene class, affects the binding of group B compounds (as well as the macrolides and lincosamides; hence, MLSB resistance), but group A and B compounds usually maintain their synergy and their bactericidal effect against MLSB-resistant strains. erm genes are widespread both geographically and throughout numerous bacterial genera. Several types of enzymes (acetyltransferases, hydrolases) have been identified that inactivate the group A or the group B compounds. Genes involved in streptogramin efflux have so far been found only in staphylococci, particularly in coagulase-negative species

Animals↗

PubMed1985

[Study of clinical bacteriological efficacy in a cefmenoxime ototopical solution].

One percent cefmenoxime (CMX) ototopical solution was administered to 302 patients with purulent otitis media and acute diffuse external otitis in open study fashion, and to 216 patients with purulent otitis media in double blind condition. From among the total of 518 cases various bacteria were detected, except 22 of negative detection after incubation and 3 of impossible determination. The main bacteria detected from the above 493 cases were S. aureus (242 strains = 49.1%), P. aeruginosa (105 strains = 21.3%), S. epidermidis (67 strains = 13.6%), Proteus spp. (indole positive) (31 strains = 6.3%) and P. mirabilis (24 strains = 4.9%) as well as anaerobic bacteria (26 strains = 5.3%). MIC of CMX against those bacteria detected was evaluated at 10(8) CFU/ml and 10(6) CFU/ml, respectively, up to the concentration of 800 micrograms/ml, with MIC of cefazolin (CEZ), chloramphenicol (CP) and fradiomycin (FRM) as the references. With respect to the antibacterial action of CMX against S. aureus, MIC50 of CMX was inferior to that of CEZ by 4-fold, but its MIC80 and MIC90 are almost equivalent to those of CEZ. These results were obtained because there existed relatively few CMX highly resistant strains, while more than 20% strains are said to resist cephem antibiotics. As far as MIC of CMX against P. aeruginosa was concerned, the MIC reached its peak with 100 micrograms/ml at the concentration of 10(8) CFU/ml and with 25 micrograms/ml at 10(6) CFU/ml, respectively, which indicated the real antibacterial value of CMX against P. aeruginosa. However, the strains which showed higher MIC of greater than 800 micrograms/ml were rather few, that is, only 8 out of 105 (7.6%). Antibacterial action of CMX against Streptococcus (except Enterococcus), GNR from intestinal bacteria and anaerobic bacteria was favorable, and the stable and strong antibacterial action was shown against C. freundii, Enterobacter spp., S. marcescens and Proteus spp. (indole positive) which produce chromosome mediated beta-lactamase. On the other hand, the antibacterial action of CMX against GNF-GNR except P. aeruginosa was unfavorable for P. cepacia, P. putida and A. xylosoxidans, but relatively favorable for A. calcoaceticus. As a result of MIC evaluation of reference drugs, S. aureus was resistant to CEZ, and Proteus spp. (indole-positive) was resistant to CP, while FRM was highly resisted by almost all strains of bacteria. However, the resistance rate of S. aureus to CP was relatively low, that is, as low as 16.1%.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Topical↗

PubMed1998

Antilisterial activity of enterocin 81, a bacteriocin produced by Enterococcus faecium WHE 81 isolated from cheese.

Enterocin 81, a bacteriocin produced by Enterococcus faecium WHE 81 previously isolated from cheese, exhibited a very narrow spectrum of activity, which is mainly directed against enterococci and Listeria spp. including Listeria monocytogenes. Enterocin 81 activity, which was extremely rapid with maximal effect achieved within 30 min, could not be detected after treatment with various proteolytic enzymes. This activity was bactericidal in nature and induced an important efflux of intracellular material, which was visualized under electron microscopy as filaments coming out of L. monocytogenes cells. However, enterocin 81 did not display bacterial lysis on sensitive cells, as no changes in cell morphology were detected following the bactericidal action. Furthermore, this bacteriocin was shown to be equally active at pH values ranging from 4.0 to 8.0, which, along with the narrow activity spectrum, are two factors of paramount interest with regards to possible use of this bacteriocin in fermented foods.

Bacteria↗

PubMed1996

Purification, partial characterisation and mode of action of enterococcin EFS2, an antilisterial bacteriocin produced by a strain of Enterococcus faecalis isolated from a cheese.

Enterococcus faecalis strain EFS2, isolated from the surface of a traditional cheese, produced a bacteriocin active against Gram-positive bacteria including Listeria spp. and some Staphylococcus aureus strains. The bacteriocin, named enterococcin EFS2, has been purified to homogeneity by ammonium sulphate precipitation and reversed-phase high performance liquid chromatography (RP-HPLC). The molecular weight was determined by mass spectrometry to be 7149.6. The amino acid composition of enterococcin EFS2 revealed that it contained 67 amino acid residues and had a blocked amino-terminal end. Enterococcin EFS2 induced viability loss, efflux of K+ ions and ATP, and cell lysis. Kinetic study of bactericidal activity of enterococcin EFS2 on Listeria innocua strain LIN11 indicated slower cell destruction than by nisin. At pH 7.0, the activity of enterococcin EFS2 was the highest at 35 degrees C and was lost at 15 degrees C. The bacteriocin was more active against L. innocua strain LIN11 in broth adjusted to pH 6.0, 7.0 and 8.0 than to pH 4.5 at 30 degrees C.

Amino Acids↗

PubMed1995

E-4695, a new C-7 azetidinyl fluoronaphthyridine with enhanced activity against gram-positive and anaerobic pathogens.

E-4695, (-)-7-[3-(R)-amino-2-(S)-methyl-1-azetidinyl]-1-cyclopropyl-1,4- dihydro-6-fluoro-4-oxo-1,8-naphthyridine-3-carboxylic acid, is a new fluorinated naphthyridine with an azetidine moiety. The MICs of E-4695 at which 90% of the isolates were inhibited (MIC90s) were 0.06 to 0.5 microgram/ml for gram-positive cocci, including species of the genera Staphylococcus, Streptococcus, and Enterococcus, and the MIC90s against gram-negative pathogens such as members of the family Enterobacteriaceae (with the exception of Providencia spp. [MIC90, 8 micrograms/ml]) and Pseudomonas aeruginosa were 0.015 to 0.5 microgram/ml. E-4695 inhibited 90% of the Clostridium perfringens and Bacteroides fragilis isolates at 0.25 and 4 micrograms/ml, respectively. Against gram-positive cocci the potency of E-4695 was 2- to 8-fold higher than that of ciprofloxacin, 4- to 8-fold higher than that of ofloxacin, and 8- to 16-fold higher than that of fleroxacin. Against enteric bacteria and P. aeruginosa the potency of E-4695 was, in general, similar to that of ciprofloxacin and eightfold higher than those of ofloxacin and fleroxacin. E-4695 was four- and eightfold more potent than ciprofloxacin against C. perfringens and B. fragilis isolates, respectively. E-4695 and ciprofloxacin showed similar properties when the effects of pH or magnesium concentration were tested on them. E-4695 and ciprofloxacin had substantial reductions of activity only when pH decreased below 4.8. E-4695 and ciprofloxacin activities were not markedly affected by the presence of 5 or 10 mM Mg2+. The presence of serum and human urine at pH 7.2 decreased the activity of E-4695 between two- and fourfold. After an oral dose of 50 mg/kg of body weight, the maximum level in serum, the biological half-life, and the area under the concentration-time curve from 0 to 10 h for E-4695 were 13.2 microgram/ml, 3.3 h, and 45.6 microgram . h/ml, respectively. The area under the concentration-time curve from 0 to 4 h for ciprofloxacin was 2.3 microgram . h/ml at the same dose. Fifty-percent effective doses (ED50S) against Staphylococcus aureus HS-93 infections in mice were 4.5 mg/kg with E-4695 and 37.6 mg/kg with ciprofloxacin. Infection with Streptococcus pneumoniae 29206 was more effectively treated with E-4695 (ED50, 41,2 mg/kg) than with ciprofloxacin (ED50, 200 mg/kg). The ED50 of E-4695 for infections with Streptococcus pneumoniae 1625 was 132.2 mg/kg; ciprofloxacin was ineffective at 400 mg/kg against this strain. E-4695 was also more potent than ciprofloxacin in treatment of infections caused by gram-negative organisms such as Escherichia coli HM-42 (ED50S, 1.0 and 3.9 mg/kg, respectively). The ED50S of E-4695 and ciprofloxacin were 33.0 and 145.5 mg/kg against P. aeruginosa HS-116 and 9.6 and 18.9 mg/kg against P. aeruginosa B-120, respectively. The therapeutic efficacy of E-4695 may depend not only on its in vitro activity but also on its improved pharmacokinetic properties.

Animals↗

PubMed1996

Distribution of thiols in microorganisms: mycothiol is a major thiol in most actinomycetes.

Mycothiol [2-(N-acetylcysteinyl)amido-2-deoxy-alpha-D-glucopyranosyl- (1-->1)-myo-inositol] (MSH) has recently been identified as a major thiol in a number of actinomycetes (S. Sakuda, Z.-Y. Zhou, and Y. Yamada, Biosci. Biotech. Biochem. 58:1347-1348, 1994; H. S. C. Spies and D. J. Steenkamp, Eur. J. Biochem. 224:203-213, 1994; and G. L. Newton, C. A. Bewley, T. J. Dwyer, R. Horn, Y. Aharonowitz, G. Cohen, J. Davies, D. J. Faulkner, and R. C. Fahey, Eur. J. Biochem. 230:821-825, 1995). Since this novel thiol is more resistant than glutathione to heavy-metal ion-catalyzed oxidation, it seems likely to be the antioxidant thiol used by aerobic gram-positive bacteria that do not produce glutathione (GSH). In the present study we sought to define the spectrum of organisms that produce MSH. GSH was absent in all actinomycetes and some of the other gram-positive bacteria studied. Surprisingly, the streptococci and enterococci contained GSH, and some strains appeared to synthesize it rather than import it from the growth medium. MSH was found at significant levels in most actinomycetes examined. Among the actinobacteria four Micrococcus species produced MSH, but MSH was not found in representatives of the Arthrobacter, Agromyces, or Actinomyces genera. Of the nocardioforms examined, Nocardia, Rhodococcus, and Mycobacteria spp. all produced MSH. In addition to the established production of MSH by streptomycetes, we found that Micromonospora, Actinomadura, and Nocardiopsis spp. also synthesized MSH. Mycothiol production was not detected in Propionibacterium acnes or in representative species of the Listeria, Staphylococcus, Streptococcus, Enterococcus, Bacillus, and Clostridium genera. Examination of representatives of the cyanobacteria, purple bacteria, and spirochetes also gave negative results, as did tests of rat liver, bonito, Candida albicans, Neurospora crassa, and spinach leaves. The results, which indicate that MSH production is restricted to the actinomycetes, could have significant implications for the detection and treatment of infections with actinomycetes, especially those caused by mycobacteria.

Actinomycetales↗

PubMedDate not supplied

In vitro activity of cefdinir (FK482) and ten other antibiotics against gram-positive and gram-negative bacteria isolated from adult and pediatric patients.

The in vitro activity of cefdinir, an oral aminothiazolyl hydroxyimino cephalosporin was compared with that of cefixime, cefpodoxime, cefaclor, cephalexin, ciprofloxacin, ofloxacin, oxacillin, ampicillin, vancomycin and trimethoprim-sulfamethoxazole against 279 gram-positive and gram-negative recent clinical isolates from adult and pediatric patients. Cefdinir was the most active drug among the cephalosporins against oxacillin-sensitive Staphylococcus aureus and coagulase-negative staphylococci, Streptococcus pneumoniae, S. pyogenes, Escherichia coli and Moraxella catarrhalis (MIC90 0.015-2 mg/l). Cefixime was the most active agent against Hemophilus influenzae, Klebsiella pneumoniae, K. oxytoca, Proteus mirabilis and P. vulgaris (MIC90 < 0.015-0.125 mg/l). The activity of cefpodoxime was better than that of cefixime against S. pneumoniae and oxacillin-sensitive staphylococci (MIC90 0.25-8 vs. 0.5-32 mg/l), similar to cefixime against S. pyogenes (MIC90 0.06 mg/l) and not as good as cefixime against H. influenzae, M. catarrhalis, Klebsiella spp. and Proteus spp. (MIC90 < 0.015-0.25 vs. 0.125-0.5 mg/l). The activity of cefdinir was greater than that of the other cephalosporins against Enterococcus faecalis (MIC90 16-32 vs. > 64 mg/l). None of the cephalosporins were active against methicillin-resistant, coagulase-positive or -negative staphylococci or Pseudomonas aeruginosa (MIC90 > 64 mg/l). Overall, the susceptibilities of adult and pediatric isolates were similar. Kinetic kill curves demonstrated rapid and similar killing at 6 h by cefdinir, cefixime, cefpodoxime and ofloxacin. At 24 h at 1 x MIC, the least regrowth was observed with cefdinir and cefpodoxime; at 2 x MIC, suppression of growth was similar with all four drugs.

Adult↗

PubMed1990

Comparative in vitro and in vivo activities of six new monofluoroquinolone and difluoroquinolone 3-carboxylic acids with a 7-azetidin ring substituent.

E-4502, E-4501, E-4500, E-4480, E-4474, and E-4441 are new monofluorinated or difluorinated quinolone agents that are chemically characterized by the presence of an azetidin ring, with different C'-3 substituents, at position 7 of the molecular structure. The MICs of the difluorinated compounds E-4501, E-4474, and E-4441 for 90% of isolates were 0.06 to 1, 0.06 to 1, and 0.12 to 1 microgram/ml, respectively, against gram-positive organisms (staphylococci, streptococci, and Enterococcus faecalis); 0.0015 to 0.12, 0.015 to 0.12, and 0.03 to 0.12 microgram/ml, respectively, against members of the family Enterobacteriaceae except Providencia spp.; and 1, 1, and 2 micrograms/ml, respectively, against Pseudomonas aeruginosa. E-4501, E-4474, and E-4441 inhibited all anaerobic bacteria at concentrations of 1, 2, and 4 micrograms/ml, respectively. Difluorinated compounds were significantly more active than the corresponding monofluorinated analogs E-4502, E-4500, and E-4480 against aerobic and facultatively anaerobic organisms, as well as against anaerobes. Considering monofluorinated and difluorinated compounds, activity in moderate ascending order was observed in quinolones containing an amine and a methyl group (E-4441 and E-4480), an amine group (E-4474 and E-4500), and a methylamine group (E-4501 and E-4502) in the C'-3 position of the azetidin ring. E-4501, E-4474, and E-4441 were more active than norfloxacin and DR-3355 [S-(-)-ofloxacin], had activities comparable to or slightly lower than that of ciprofloxacin against gram-negative bacteria, and were more active than all the reference quinolones against gram-positive organisms and anaerobes. E-4502 and E-4501, which were used to determine the effect of pH, were less active in acidic medium. In general, E-4502, E-4501, E-4500, E-4480, E-4474, and E-4441 activities were not affected or increased in medium containing serum but decreased in the presence of 10 mM Mg2+ or in human urine at pH 5.5. The protective effect of E-4501, E-4474, and E-4441 after oral administration against systemic infections with Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa in mice was greater than that of ciprofloxacin.

4-Quinolones↗

PubMedDate not supplied

Vaginal bacterial flora activates rat peritoneal mast cells.

Sixteen strains of physiological and pathological vaginal bacteria were tested for their ability to secrete histamine from rat peritoneal mast cells in vitro. We noticed that Mycoplasma hominis-induced histamine release was very high (up to 53.6%). The stimulation of rat mast cells with Staphylococccus cohnii, Staphylococcus coagulase(-) (two strains), Ureaplasma urealyticum, Peptostreptococcus spp., Bacteroides capillosus, Staphylococcus aureus and Streptococcus agalactiae resulted in lower but significant histamine secretion (11.2%-17.5%). Other bacteria strains (Staphylococcus epidermidids, Enterococcus faecalis, Escherichia coli, Actinomyces naeslundii (two strains) and Lactobacillus fermentum (two strains) caused very low (4.2% - 8.8%) histamine release.

Journal Article↗

PubMed1996

Production and characterization of enterocin 900, a bacteriocin produced by Enterococcus faecium BFE 900 from black olives.

Enterococcus faecium BFE 900 isolated from black olives produced a bacteriocin termed enterocin 900, which was antagonistic towards Lactobacillus sake, Clostridium butyricum, enterococci as well as Listeria spp. including Listeria monocytogenes. Enterocin 900 was inactivated by pepsin, alpha-chymotrypsin, proteinase K and trypsin but not by catalase, alpha-amylase, or other non-proteolytic enzymes tested. The bacteriocin was heat stable, retaining activity after heating at 121 degrees C for 15 min. Enterocin 900 was active at pH values ranging from 2.0-10.0, with highest activity at pH 6.0. Bacteriocin production occurred in the late logarithmic growth phase when culture density was ca. log 8.0 CFU ml-1. Enterocin 900 was produced in media with initial pH ranging from 6.0-10.0, but not in media with a pH lower than 6.0. Medium composition, especially the concentrations of peptone and yeast extract influenced bacteriocin production, with no bacteriocin being produced in the absence of either of these compounds. No plasmids could be isolated from Enterococcus faecium BFE 900, indicating that the gene for bacteriocin activity is located on the chromosome.

Bacteriocins↗

PubMed2001

Linezolid: a review of its use in the management of serious gram-positive infections.

UNLABELLED: Linezolid is the first of a new class of antibacterial drugs, the oxazolidinones. It has inhibitory activity against a broad range of gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-intermediate S. aureus (GISA), vancomycin-resistant enterococci (VRE) and penicillin-resistant Streptococcus pneumoniae. The drug also shows activity against certain anaerobes, including Clostridium perfringens, C. difficile, Peptostreptococcus spp. and Bacteroidesfragilis. In controlled phase III studies, linezolid was as effective as vancomycin in the treatment of patients with infections caused by methicillin-resistant staphylococci and also demonstrated efficacy against infections caused by VRE. Further phase III studies have demonstrated that linezolid is an effective treatment for patients with nosocomial pneumonia, for hospitalised patients with community-acquired pneumonia, and for patients with complicated skin or soft tissue infections (SSTIs). In these studies, linezolid was as effective as established treatments, including third-generation cephalosporins in patients with pneumonia, and oxacillin in patients with complicated SSTIs. Oral linezolid 400 or 600mg twice daily was as effective as clarithromycin 250mg twice daily or cefpodoxime proxetil 200mg twice daily in the treatment of patients with uncomplicated SSTIs or community-acquired pneumonia. Linezolid is a generally well tolerated drug. The most frequently reported adverse events in linezolid recipients were diarrhoea, headache, nausea and vomiting. Thrombocytopenia was also documented in a small proportion (about 2%) of patients treated with the drug. CONCLUSIONS: Linezolid has good activity against gram-positive bacteria, particularly multidrug resistant strains of S. aureus (including GISA), Enterococcus faecium and E. faecalis (including VRE). In controlled clinical trials, linezolid was as effective as vancomycin in eradicating infections caused by methicillin-resistant Staphylococcus spp. and has demonstrated efficacy against infections caused by VRE. As the level of resistance to vancomycin increases among S. aureus and enterococci, linezolid is poised to play an important role in the management of serious gram-positive infections.

Acetamides↗

PubMed1989

Comparative in-vitro activity of meropenem against clinical isolates including Enterobacteriaceae with expanded-spectrum beta-lactamases.

Meropenem, a new parenteral carbapenem, was tested in vitro by an agar-dilution method against 373 standard strains (aerobes and anaerobes) and against nine expanded-spectrum beta-lactamase-producing strains and their transconjugants (5 CTX-1, 2 CAZ-1, 2 CAZ-2). Meropenem was compared with methicillin, imipenem, piperacillin, cefoxitin, cefotaxime, ceftazidime, gentamicin, chloramphenicol, clindamycin, ciprofloxacin, vancomycin and metronidazole. Meropenem and imipenem exhibited an extended spectrum of activity, with low MICs. Only methicillin-resistant staphylococci, and Pseudomonas (Xanthomonas) maltophilia were resistant. Of the carbapenems, imipenem was more active against methicillin-susceptible staphylococci, streptococci and Enterococcus faecalis, but meropenem was markedly more active against all the Enterobacteriaceae and some pseudomonads. Both had similar activity against Ps. aeruginosa, Acinetobacter spp. and anaerobes. The carbapenem MICs were very low for Enterol acteriaceae producing the expanded-spectrum beta-lactamases. Against CTX-1-producing strains resistant to cefotaxime and ceftazidime and against CAZ-1 or CAZ-2-producers highly resistant to ceftazidime meropenem was the most active, with MICs lower (0.03-0.12 mg/l) than those of imipenem (0.06-0.5 mg/l), for wild type producers and their transconjugants.

Bacteria↗

PubMed1997

In vitro activity and spectrum of LY333328, a novel glycopeptide derivative.

Reference methods were used to determine the potency of LY333328, a semisynthetic glycopeptide derivative with a key N-alkylation substitution, against 833 strains (393 gram-positive strains and representative gram-negative bacilli) with various defined resistance mechanisms. The MICs at which 90% of the isolates are inhibited (MIC90S) (in micrograms per milliliter) of LY333328 and the percentages of strains at < or = 8 micrograms/ml were as follows: for oxacillin-susceptible Staphylococcus aureus, 2 and 100%, and for oxacillin-resistant Staphylococcus aureus, 4 and 100%; for oxacillin-susceptible Staphylococcus epidermis, 4 and 100%, and for oxacillin-resistant Staphylococcus aureus, 8 and 96%; for Streptococcus serogroups A, B, C, and G, 0.25 to 1 and 100%; for Streptococcus pneumoniae < or = 0.015 to 0.06 and 100%; for Enterococcus faecalis, 2 and 100%; and for vancomycin-susceptible Enterococcus faecium, 0.25 and 100%, and for vancomycin-resistant Enterococcus faecium, 4 and 100%. LY333328 was not active (MIC50, > or = 16 micrograms/ml) against more than 400 representative strains of Enterobacteriaceae, pseudomonads, Acinetobacter spp., Stenotrophomonas maltophilia, Haemophilus influenzae, Moraxella catarrhalis, pathogenic Neisseria spp., and anaerobic gram-negative bacilli. Gram-positive anaerobes were LY333328 susceptible (MICs, < or = 2 micrograms/ml). Test methods and conditions may have affected MICs of LY333328, with most (species variation) agar dilution MICs being greater than the broth microdilution MICs.

Anti-Bacterial Agents↗

PubMed1991

Differentiation of Lactococcus lactis and Lactococcus garvieae from humans by comparison of whole-cell protein patterns.

We tested 12 reference and 24 clinical strains of lactococci for physiologic characteristics using a conventional test system, the Gen-Probe Enterococcus 2 chemiluminescence assay (Gen-Probe Inc., San Diego, Calif.), the Rapid Strep identification system (Analytab Products, Plainview, N.Y.), and whole-cell protein analysis. The Gen-Probe Enterococcus 2 chemiluminescence assay for Enterococcus identification was negative with all strains. Neither the conventional test nor the Rapid Strep identification system could differentiate between the two Lactococcus spp. most commonly isolated from humans. A simple procedure, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was developed for comparing the whole-cell protein patterns of Lactococcus spp. L. lactis and L. garvieae were differentiated by unique protein patterns.

Bacterial Proteins↗

PubMed1991

[Pediatric bacteremia strains grow in blood culture media].

Bacteremia strains may influence the clinical therapy, the isolation of bacteremia strains is important for patients. In order to understand the distribution and the growth in the blood culture media of bacteremia strains, from January 1982 through December 1988 we studied the blood culture sent to us from the pediatric ward. These were three hundred and forty one bacterial strains (3.1%) isolated from patients. In the meantime we also studied the bacteremia strains growth in the blood culture media. In these positive cultures, there were 83 gram-positive, and 258 gram-negative strains. The 83 gram-positive included Staphylococcus aureus (38 strains), hemolytic streptococcus (22 strains), Enterococcus (13 strains), Streptococcus pneumoniae (8 strains) and others (2 strains). The 258 gram-negative strains included Escherichia coli (97 strains), Salmonella spp. (43 strains), Enterobacter spp. (31 strains). Klebsiella spp. (23 strains), Pseudomonas spp. (25 strains), Proteus spp. (17 strains), Citrobacter spp. (11 strains) and others (11 strains). The Growth of bacteremia strains in the blood culture medium, showed that first day isolation strains were 33.7%, second day strains 24.9%, third day were 19.9%, fourth day were 13.5%, fifth day were 3.2%, sixth day were 4.1% and seventh day were 0.6%. In conclusion, the bacteremia strains showed that the gram-negative, which were 75.7%, were more prevalent than the gram-positive which were 24.3%, the isolation of the strains was more in the first to fourth day and grew by 92%, on the fifth day it grew by 3.2% and on the seventh day by only 0.6%. On the fifth day the baby had recovered and we were able to discontinue antibiotic therapy.

Blood↗