Search PubMed⌕ Search

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.

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

At least 325 records · Page 18Linked to original sources

Bacteriocin-like substance (BLS) production in Aeromonas hydrophila water isolates.

30 Aeromonas hydrophila water isolates were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria, including food-borne pathogens. A. hydrophila showed antibacterial activity against one or more indicator microorganisms, but the activity emerged only with non-phylogenetically related genera or species. In particular all A. hydrophila showed antibacterial activity against one or more of the tested Staphylococcus strains, five against Listeria spp. (Listeria seeligeri, Listeria welshimeri and Listeria ivanovii), and eight presented a weak antagonistic activity towards Streptococcus agalactiae and Lactobacillus spp. Inhibitory activity was not observed against the other Gram-positive (Listeria monocytogenes, Listeria innocua and Enterococcus spp.) and Gram-negative tested strains, including Aeromonas sobria, Aeromonas caviae and the same A. hydrophila, when used as indicator. Anti-staphylococcal activity was observed with a gradual increase of the inhibition zone during incubation and seemed to be influenced by A. hydrophila hemolytic expression. Extrachromosomal analysis showed the presence, in 70% of the strains, of one to five plasmids with molecular masses ranging from 2.1 to 41.5 MDa, but it was not possible to relate this result with BLS production.

Aeromonas hydrophila↗

Penicillin resistance and aminoglycoside-penicillin synergy in enterococci.

Susceptibility to penicillin, vancomycin, imipenem, streptomycin, kanamycin and gentamicin was tested in 130 clinical isolates of Enterococcus spp. by an agar dilution method. Penicillin resistance (MIC > 8 mg/l) was only observed among strains of Enterococcus faecium and Enterococcus raffinosus. Thirty-nine percent of the penicillin-resistant enterococci showed low-level resistance to at least one of the three aminoglycosides tested (gentamicin, kanamycin and streptomycin). Six Enterococcus strains (5 E. faecium and 1 E. raffinosus) with low-level resistance to gentamicin and different MICs for penicillin were tested for antibiotic synergy using time-killing curves. When penicillin concentrations equal to or higher than the MICs were used, synergism was established, even when highly penicillin-resistant strains (MIC > 200 mg/l) were tested. No synergy was observed when penicillin concentrations were below the MICs.

Aminoglycosides↗

[Isolation rate of E. coli from surgical infections and their susceptibilities].

Escherichia coli isolated from surgical infections during the period from July 1983 to June 1995 were investigated in a multicenter study involving 19 hospitals in Japan, and the following results were obtained. 1. Although the isolation rate of E. coli was not high from postoperative infections, it was most frequently isolated from primary infections throughout the study period. E. coli, Klebsiella spp. and anaerobic bacteria were predominant from fresh infections. From the cases that had previous antibiotics treatment, Enterococcus spp. were the most predominant isolates followed by MRSA and Pseudomonas spp. in this order. 2. Against E. coli, cefozopran, carumonam and aztreonam had the strongest activity, followed by cefmenoxime, imipenem, latamoxef, gentamicin and ofloxacin. Recently, we have noticed that antibiotic resistant E. coli strains particularly against cefazolin are increasing year by year.

Anti-Bacterial Agents↗

Vancomycin-resistant enterococci: the clinical effect of a common nosocomial pathogen.

Enterococcus spp. is now the third most common pathogen among hospitalized patients, accounting for nearly 12% of nosocomial infections. Enterococcus faecalis is the most prevalent enterococcal species (85%-89%), whereas Enterococcus faecium accounts for 10%-15% of enterococcal isolates. Only 5% of E. faecalis isolates are resistant to glycopeptides. E. faecium has also been shown to be resistant to nonglycopeptide compounds, such as penicillins (97%), high-level gentamicin (52.1%), and high-level streptomycin (58.3%). Numerous risk factors for vancomycin-resistant enterococci (VRE) have been identified, including as length of hospital- or ICU-stay, proximity to a hospitalized, colonized VRE, patient severity of illness, renal failure, recent surgery, immunosuppression, and organ recipient status. An important risk factor is prior exposure to antibiotics such as vancomycin, ceftazidime, ciprofloxacin, and metronidazole, as well as the number and duration of recent antibiotics. Interventions to reduce nosocomial VRE cross-transmission have also been studied. Using gowns in addition to gloves diminished the incidence of VRE in one study, but had a negligible effect in a second study. Studies have shown that in many cases (> 60%) vancomycin usage is inappropriate. While controlling the use of vancomycin alone has only variably diminished VRE colonization, other efforts such as narrowing the spectrum of antibiotics, antiseptics, and reducing immunosuppression may be salutary. Attempts to eradicate VRE intestinal carriage with enteral agents (bacitracin, tetracycline + rifampin, novobiocin) have been reported but seem to have only a transient effect. Non-antimicrobial interventions such as removal of intravenous or bladder catheters and/or surgical or percutaneous drainage may be beneficial. In addition, the development of new antimicrobial agents such as streptogramins, glycopeptides, everninomicins, and oxazalididones will hopefully play an important role in reducing morbidity from these pathogens.

Anti-Bacterial Agents↗

Influence of transient salivary flora on assessment of mutans streptococci level by the "Strip mutans" method.

The Dentocult SM ("Strip mutans") method occasionally shows decoloration of broth and of colonies of mutans streptococci on the plastic strip, thereby making interpretation difficult. In an attempt to explain the phenomenon and to investigate the influence of the salivary flora on the "Strip mutans" method, a total of 46 subjects were sampled. Saliva was analyzed using the "Strip mutans" method and conventional plating techniques to identify mutans streptococci, enterococci, staphylococci, enteric bacteria, and yeasts. Approximately 85% of the "Strip mutans" scores coincided with the conventional MSB-plating method. Two samples showed decolored mutans streptococci colonies on the "Strip mutans" strip. Enterococcus spp. were present in the saliva of these test subjects and could grow in the "Strip mutans" broth. Enterococcus faecalis was able to induce the same type of decoloration under experimental pure culture conditions. Three "Strip mutans" samples showed small colonies of mutans streptococci, visible only under magnification (x 10-20). Staphylococcus epidermidis was present in these saliva samples and showed heavy growth in the broth. Under experimental pure culture conditions S. epidermidis also inhibited the growth of mutans streptococci to some extent.

Adult↗

In vitro antibacterial activity of men 10700, a new penem antibiotic.

We report here the antibacterial activity of the new penem antibiotic Men 10700 against a total of 740 gram-positive and gram-negative clinical isolates, in comparison to imipenem, meropenem, cefotaxime, ceftriaxone, ciprofloxacin and gentamicin. Men 10700 has shown a wide spectrum of antibacterial activity, with a potent activity both against gram-positive species (with the exception of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis) as indicated by minimal inhibitory concentration (MIC(90)) values < or =0.5 mg/l, and gram-negative species, with MIC(90) values generally < or =2 mg/l. Men 10700 was the most potent antibiotic against methicillin-susceptible S. aureus and S. epidermidis, while the overall spectrum of activity resembled that of imipenem; meropenem was more active against most gram-negative species. In comparison with third-generation cephalosporins, Men 10700 demonstrated superior activity against methicillin-susceptible S. aureus and S. epidermidis and some gram-negative species such as Morganella morganii, Serratia spp. and Enterobacter cloacae; moreover, in contrast to third-generation cephalosporins, Men 10700 showed moderate activity against Enterococcus spp. The activity of Men 10700 against penicillin-resistant Streptococcus pneumoniae (10 strains) and some gram-negative strains selected for their resistance to cefotaxime (20 strains) was particularly interesting.

Anti-Bacterial Agents↗

Antimicrobial susceptibility of bacteria isolated from pinnipeds stranded in central and northern California.

Over a 2-yr period (1994-1995), the antimicrobial susceptibilities of 129 bacterial isolates recovered from live stranded California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) were studied. Nineteen genera of bacteria were isolated from various sites of inflammation; abscesses and umbilici were the most common sites. Seventy-two percent of the bacterial isolated were gram negative, and the Enterobacteriaceae (Escherichia coli, Proteus spp., Klebsiella spp., Salmonella spp.) accounted for 75% of the gram-negative isolates. All of the gram-positive isolates were either Enterococcus spp. or Staphylococcus aureus. Multiple drug resistance was present in all but one of the bacterial isolates. The gram-positive bacteria were most susceptible to amoxicillin-clavulanic acid (77% of 36 isolates) and least susceptible to lincomycin (18% of 11 isolates). The gram-negative bacteria were most susceptible to amikacin (91% of 91 isolates) and least susceptible to clindamycin (3% of 109 isolates).

Abscess↗

In vitro activity of 19 antimicrobial agents against 3513 nosocomial pathogens collected from 48 Canadian medical centres. The Canadian Antimicrobial Study Group.

Antimicrobial resistance is a global concern. Differentiation between susceptibility rates for nosocomial versus community pathogens is important epidemiologically because it impacts on the appropriate empirical selection of antimicrobial therapy for infected patients. We studied resistance rates for 3513 nosocomial pathogens from 48 Canadian medical centres tested against 19 antimicrobial agents. The following are percent susceptibility for ceftazidime, ceftriaxone, ciprofloxacin, imipenem, netilmicin, and ticarcillin/clavulanic acid, respectively: Enterobacteriaceae 95, 95, 97, 99 98, 89; Escherichia coli, all 99 except ticarcillin/clavulanic acid (91); Enterobacter spp. 78, 78, 96, 99, 99, 71; Citrobacter spp. 79, 80, 89, 100, 94, 73; Proteus spp. 99, 88, 99, 88, 99, 98; Pseudomonas aeruginosa 88, 20, 82, 88, 81, 36; Staphylococcus aureus, all > 95; Enterococcus spp. 4, 9, 62, 95, 43, 38. Susceptibility rates for other species of microorganisms and agents tested varied considerably. Some institutions had higher than average resistance rates for some pathogens (i.e. P. aeruginosa) and some agents. Detection and continued surveillance of antimicrobial resistance amongst nosocomial pathogens is vital to patient care and health care resources. The control of antimicrobial resistance can help maintain antibiotic usage and costs associated with the use of ever more potent drugs and the treatment of increasingly resistant infections.

Canada↗

Identification of clinically important species of Enterococcus within 1 day with randomly amplified polymorphic DNA (RAPD).

The use of randomly amplified polymorphic DNA (RAPD) for rapid, reliable, and easily interpreted identification of enterococci was evaluated. Nineteen type strains of Enterococcus, 12 reference strains, and 114 clinical isolates of Enterococcus were analyzed. Discrimination was obtained between most type strains, the exceptions being Ent. casseliflavus and Ent. flavescens, which had relatively similar RAPD-profiles. Ent. faecalis and Ent. faecium were readily separated, and Ent. gallinarum and Ent. durans could also be identified. Extracts to be used in the polymerase chain reaction (PCR) were prepared directly from agar plate colonies, which made it possible to complete the identification procedure in one day. RAPD was proved to be a fast and reliable method for identification of most Enterococcus spp. of clinical significance.

Enterococcus↗

Identification of enterococci at the species level by sequencing of the genes for D-alanine:D-alanine ligases.

A PCR assay based on the use of degenerate oligodeoxyribonucleotides allowed characterization of a fragment internal to the ddl genes encoding D-alanine:D-alanine ligases in Enterococcus columbae, E. durans, E. malodoratus, E. mundtii, E. raffinosus, E. seriolicida, E. solitarius, and E. sulfureus. Phylogenetic analysis of the sequence of the amplification products and of those already obtained from E. aviuni, E. casseliflavus, E. cecorum, E. dispar, E. faecalis, E. faecium, E. flavescens, E. gallinarurm, E. hirae, E. pseudoavium, and E. saccharolvticus yielded an evolutionary tree with a topology similar to that based on 16S rRNA sequences. Partial sequencing of the ddl gene can therefore be used for genotypic identification of Enterococcus spp.

Amino Acid Sequence↗

Rapid identification of Streptococcus bovis by using combination constitutive enzyme substrate hydrolyses.

Several studies have documented the association of blood and rectal-culture positivity for Streptococcus bovis with gastrointestinal neoplasia, especially colonic carcinoma. Conventional methods using bile-esculin hydrolysis, salt tolerance, and sugar fermentations to differentiate S. bovis from other streptococci are laborious, slow, and relatively expensive. Commercially available systems are costly and require at least 24 to 48 h of incubation. A rapid identification procedure for S. bovis and related bacteria was developed. The method uses a reagent containing two hydrolyzable substrates, p-nitrophenyl-alpha-D-galactopyranoside and 4-methylumbilliferyl-beta-D-glucoside, in the presence of 2.5% sodium deoxycholate. This combination test, performed with a rapid assay for L-pyrrolidonyl-aminopeptidase, could distinguish S. bovis, Streptococcus equinus, Enterococcus spp., Streptococcus pneumoniae, and the viridans group streptococci in culture within 30 min. Twelve species of the genera Streptococcus and Enterococcus were tested. The rapid method correlated well with conventional techniques. The reagents are readily available, inexpensive, and easy to make and can be stored in the refrigerator for at least 6 months.

Costs and Cost Analysis↗

Five-year prospective study of bacteraemic urinary tract infection in a single institution.

In order to determine the epidemiology, microbiology, and outcome of bacteraemia originating in the urinary tract in hospitalised patients, a prospective study was conducted in a large general hospital in Israel. Data from all patients with bacteraemia were collected prospectively, and a subgroup of patients with bacteraemia secondary to urinary tract infection was analysed. There were 702 episodes of bacteraemia secondary to urinary tract infection during a five-year period (33.9% of all episodes of bacteraemia). The mean age of the patients was 76 years, and the male:female ratio was 0.9:1.0. The most common pathogens were Escherichia coli (52%), Klebsiella spp. (14%), and Proteus spp. (9%). Pseudomonas spp. were isolated from 8% of all patients, from 19% of those who had received antibiotics, and from 15% of males. Enterococcus spp. were isolated from 4% of males but from no females. Five percent of the episodes were polymicrobial, and 16% of the infections were hospital acquired. On logistic multivariate regression analysis, predictors of mortality were: hospitalisation in a medical department, hospital-acquired infection, inappropriate empiric antibiotic treatment, presence of decubitus ulcer(s), respiratory or renal failure, and elevated urea and decreased albumin levels.

Adolescent↗

A three year survey of clinical isolates in the United Kingdom and their antimicrobial susceptibility.

A United Kingdom national survey of clinical isolates and their antimicrobial susceptibility was performed, with 61 participating hospital laboratories, between 1986 and 1989. Each centre used Microbe Base, a commercial suite of micro-computer programs which can record and analyse antimicrobial susceptibility data Informative on 366,853 bacterial isolates and their antimicrobial susceptibility was received from hospital and domiciliary specimens; Candida spp. accounted for a further 9121 isolates. The sites of origin were urine 51%, skin and soft tissue 21%, lower respiratory tract 8%, genital tract 7%, ear, nose and throat 6%, eye 3%, blood 1.5% and faeces 1%. Gram-negative bacteria accounted for 242,307 isolates, the main species were Escherichia coli 48%, Proteus spp. 9%, Pseudomonas spp. 7%, Haemophilus influenzae 6% and Klebsiella spp. 4%. Gram-positive bacteria numbered 124,546 with a predominance of Staphylococcus aureus 42%, beta-haemolytic streptococci 20%, Enterococcus spp. 12%, coagulase negative staphylococci 10% and Streptococcus pneumoniae 5%. All pneumococci were sensitive to penicillin, and methicillin resistant in Staph. aureus was only 2%. Twelve per cent of H. influenzae strains were resistant to ampicillin. There were no significant levels of gentamicin resistance in Gram-negative bacilli.

Drug Resistance, Microbial↗

Isolation of three strains of beta-lactamase-producing Enterococcus faecalis in Argentina.

Of the 90 strains of Enterococcus spp. isolated in an Argentine laboratory in the period from January to July 1989, three were identified as beta-lactamase-producing Enterococcus faecalis. According to the literature reviewed, these appear to be the first beta-lactamase-positive strains of Enterococcus isolated outside the USA. They differed from most beta-lactamase-producing strains already described in that they were susceptible to low concentrations of macrolides. All three strains were resistant to high concentrations of aminoglycosides.

Aminoglycosides↗

In vitro activity of RP 59500 (quinupristin/dalfopristin) against antibiotic-resistant strains of Streptococcus pneumoniae and enterococci.

The activity of RP 59500 (quinupristin/dalfopristin) was evaluated in vitro against antibiotic-resistant strains of Streptococcus pneumoniae (N = 15) and Enterococcus spp. (N = 43). By broth dilution MIC tests RP 59500 was highly active against penicillin-resistant S. pneumoniae and vancomycin-resistant Enterococcus faecium, but showed poor activity against E. faecalis. In time-kill studies the drug was rapidly bactericidal against S. pneumoniae but failed to kill most enterococci, even in the presence of gentamicin or human serum.

Drug Resistance, Microbial↗

Prulifloxacin.

Prulifloxacin, the prodrug of ulifloxacin, is a broad-spectrum oral fluoroquinolone antibacterial agent. After absorption, prulifloxacin is metabolised by esterases to ulifloxacin. The drug has a long elimination half-life, allowing once-daily administration. Ulifloxacin is generally more active in vitro than other fluoroquinolones against a variety of clinical isolates of Gram-negative bacteria, including community and nosocomial isolates of Escherichia coli, Klebsiella spp., Proteus, Providencia and Morganella spp., Moraxella catarrhalis and Haemophilus spp. The activity of ulifloxacin against Pseudomonas aeruginosa varies between countries. Gram-positive organisms, including meticillin- or oxacillin-susceptible Staphylococcus aureus, Enterococcus spp. and Italian community isolates of Streptococcus pneumoniae are susceptible to ulifloxacin. Activity against Spanish strains of S. pneumoniae is moderate. In well designed clinical trials, good clinical and bacteriological efficacy (similar to that of ciprofloxacin, amoxicillin/clavulanic acid or pefloxacin) was seen with prulifloxacin 600 mg once daily for 10 days in patients with acute exacerbations of chronic bronchitis or complicated lower urinary tract infections (UTIs), and with single-dose prulifloxacin 600 mg in acute, uncomplicated lower UTIs. Prulifloxacin was generally well tolerated in clinical trials, with a similar tolerability profile to that of ciprofloxacin.

Administration, Oral↗

A variety of gram-positive bacteria carry mobile mef genes.

The mefE gene codes for a membrane bound efflux protein, which confers resistance to macrolides, and has been identified in Streptococcus pneumoniae. A variety of gram-positive organisms were examined. Twenty-six isolates of S. pneumoniae carried mefE and were resistant to erythromycin (MIC of 2-16 mg/L). Two additional isolates of Emr S. pneumoniae carried both ermB and mefE(MIC of 16-128 mg/L). One Micrococcus luteus, one Corynebacterium jeikeium, three Corynebacterium spp., two viridans streptococci and seven Enterocccus spp. also carried mef genes. It was possible to move the mef gene from all 11 S. pneumoniae tested to susceptible S. pneumoniae and/or Enterococcus faecalis recipients. The addition of DNase (1 g/L) did not affect the gene transfer. It was also possible to move the mef gene from donor Enterococcus spp., viridans streptococci, M. luteus, C. jeikeium and Corynebacterium spp. to E. faecalis recipients. Transconjugant isolates were resistant to erythromycin (MIC = 16 mg/L). Hybridization with a labelled mef oligonucleotide probe against Southern blots and bacterial dot blots confirmed the presence of the mef genes. This is the first time that a mobile mef gene has been identified in four different genera, from three distinct geographical locations.

Anti-Bacterial Agents↗

In vitro activity of LY264826, a new glycopeptide antibiotic, against gram-positive bacteria isolated from patients with cancer.

The in vitro activity of LY264826, a novel glycopeptide antibiotic produced by Amycolatopsis orientalis, was compared with those of vancomycin, teicoplanin, and oxacillin against 311 gram-positive clinical isolates from patients with cancer, LY264826 had lower MICs for 90% of isolates (MIC90) than vancomycin for all species tested. It was active against oxacillin-resistant isolates including Staphylococcus aureus (MIC90, 0.5 micrograms/ml), Staphylococcus haemolyticus (MIC90, 2.0 micrograms/ml), Enterococcus spp. (MIC90, 0.5 micrograms/ml), Bacillus cereus (MIC90, 0.25 micrograms/ml), and Corynebacterium jeikeium (MIC90, 0.12 micrograms/ml). For S. aureus, including oxacillin-resistant isolates, the MICs of LY264826 were similar to those of teicoplanin. For coagulase-negative staphylococci, however, LY264826 had MICs that were 4- to 32-fold lower than those of teicoplanin. Against most streptococcal species the activities of LY264826 and teicoplanin were similar. Bactericidal activity against Staphylococcus spp. and most Streptococcus pyogenes isolates was less than or equal to 1 dilution of the MIC. One isolate of S. pyogenes and all Enterococcus faecalis strains tested were tolerant of LY264826, with MBCs greater than or equal to 32-fold greater than the MICs. The addition of 50% human serum resulted in a significant increase in activity only against Staphylococcus epidermidis. Variations in pH from 6.4 to 8.4 and in inoculum from 10(3) to 10(7) CFU/ml did not significantly affect the activity of LY264826.

Anti-Bacterial Agents↗