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E J Perea

Publications and source records attributed to E J Perea.

At least 73 records · Page 4Linked to original sources
PubMed1994

Comparative in vitro activities of new quinolones against coryneform bacteria.

The in vitro activities of eight quinolones against 115 coryneform bacteria (20 Corynebacterium jeikeium, 15 Corynebacterium minutissimum, 15 Corynebacterium striatum, 25 Corynebacterium urealyticum, 10 Corynebacterium xerosis, 10 Corynebacterium group ANF-1, 10 Corynebacterium group 12, and 10 Listeria monocytogenes) were determined. The MICs of ciprofloxacin, ofloxacin, and sparfloxacin for 90% of C. jeikeium, C. urealyticum, and C. xerosis isolates tested were > 16 micrograms/ml. Those of BAY Y 3118 and clinafloxacin against these species were 0.5 and 1 to 2 micrograms/ml, respectively. The MICs for 90% of all 115 strains tested were 0.5 microgram/ml for BAY Y 3118, 1 microgram/ml for clinafloxacin, 2 micrograms/ml for E-5068, 4 micrograms/ml for E-5065, and > 16 micrograms/ml for ciprofloxacin, ofloxacin, sparfloxacin, and E-4868.

Anti-Infective Agents↗
PubMed1994

Comparative activities of eight quinolones against members of the Bacteroides fragilis group.

The in vitro activities of five new quinolones (clinafloxacin [CI-960 or PD-127391], BAY Y 3118, E-4868, E-5065, and E-5068) against 100 Bacteroides fragilis group bacterial isolates were compared with those of ciprofloxacin, ofloxacin, and sparfloxacin. Overall, E-5068 was the most active in vitro (MIC for 90% of isolates tested [MIC90], 0.25 microgram/ml); this was followed by clinafloxacin and BAY Y 3118 (MIC90, 0.5 microgram/ml). Ciprofloxacin, sparfloxacin, and ofloxacin were the least active (MIC90s, 64, 16, and 16 micrograms/ml, respectively). B. fragilis and Bacteroides caccae were more susceptible than the other members of the B. fragilis group to all of the quinolones tested.

Anti-Infective Agents↗
PubMed1993

Effect of antimicrobial and antineoplastic drugs on the uptake of fluconazole by human neutrophils and tissue culture cells.

The effect of eight antimicrobial and three antineoplastic drugs on the uptake of fluconazole by human neutrophils and culture epithelial cells was evaluated. Fluconazole reached higher concentrations intracellularly than extracellularly (cellular to extracellular concentration ratio C/E > or = 1.3) in the presence of therapeutical concentrations of the antimicrobial and antineoplastic agents evaluated.

Anti-Infective Agents↗
PubMed1993

Susceptibility to antimicrobial agents of Pseudomonas aeruginosa attached to siliconized latex urinary catheters.

The effect of siliconized latex urinary catheters on the in vitro activity of amikacin, ceftazidime, ciprofloxacin, norfloxacin and meropenem against Pseudomonas aeruginosa was determined by a microdilution assay. MICs of amikacin and meropenem increased at least 4-fold and 16-fold respectively in the presence of catheter material. The effect of catheter material on meropenem activity was not strain dependent and was similar for different brands of catheters. The susceptibility to antimicrobial agents of Pseudomonas aeruginosa attached to catheters for 6 and 24 hours was also evaluated. When bacteria attached for 6 hours were used as inoculum, MBCs increased at least 8-fold for amikacin, 64-fold for ceftazidime, 64-fold for ciprofloxacin, 32-fold for norfloxacin and 2048-fold for meropenem. Similar results were observed when bacteria attached to catheters for 24 hours were used as inoculum. It is concluded that catheter material itself affected the in vitro activity of meropenem, and that the bactericidal activity of all antimicrobial agents against Pseudomonas aeruginosa present in biofilms on the surface of siliconized latex urinary catheters decreased dramatically, this effect being more pronounced with meropenem.

Anti-Bacterial Agents↗
PubMed1993

Effect of polyurethane catheters and bacterial biofilms on the in-vitro activity of antimicrobials against Staphylococcus epidermidis.

The effect of two polyurethane ['Cavafix Certo' (CAV); 'Viacath' (VIA)] catheters on the in-vitro activity of amikacin (AN), clindamycin (CM), cloxacillin (CX), ciprofloxacin (CIP), vancomycin (VA), teicoplanin (TEI) and daptomycin (DAP) against slime producing and non-producing Staphylococcus epidermidis strains was determined using a microdilution assay. None of the antimicrobial agents was significantly affected in the presence of the catheters. The susceptibility of S. epidermidis attached to CAV and VIA catheters was also evaluated. Minimum inhibitory concentration (MIC) values were similar when planktonic and attached bacteria were compared. Minimum bactericidal concentrations (MBCs) markedly increased in the presence of 6 and 48 h bacterial biofilms. These increases in MBC values occurred when either slime producing or non-producing strains were used, and in most cases were higher for CAV catheters than for VIA catheters. This phenomenon was shown not to be due to differences in bacterial adherence. It is concluded that the in-vitro bactericidal activity of certain antimicrobials markedly decreased when bacteria adhered to plastic catheters, but this effect could have been dependent partially on the nature of the catheters.

Anti-Bacterial Agents↗
PubMed1993

Detection of enterovirulent Escherichia coli associated with diarrhoea in Seville, southern Spain, with non-radioactive DNA probes.

To assess the role of diarrhoeagenic Escherichia coli in Southern Spain, faecal samples from 135 patients with diarrhoea and 40 healthy subjects from Seville, Andalusia, were investigated. In this prospective study, enterovirulent E. coli were identified by hybridisation with five non-radioactive DNA probes specific for enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC) and verocytotoxin-producing E. coli (VTEC). Probe-positive strains were isolated from four patients (3%) with diarrhoea and from none of the healthy controls. Two patients harboured ETEC and two patients had EPEC probe-positive strains in their faeces. No VTEC were isolated during this study. Salmonella spp. were the most frequently identified enteric pathogens, accounting for 10% of the cases, followed by Campylobacter jejuni (3%) and diarrhoeagenic E. coli (3%). This study indicates that enterovirulent E. coli play a modest role in the aetiology of diarrhoea among the indigenous population of Southern Spain.

Adult↗
PubMed1993

Uptake and intracellular activity of fluconazole in human polymorphonuclear leukocytes.

The penetration of fluconazole into human polymorphonuclear leukocytes (PMNs) and tissue culture epithelial cells (McCoy) was evaluated. At different extracellular concentrations (0.5 to 10 mg/liter), fluconazole reached cell-associated concentrations greater than the extracellular ones in either human PMNs (intracellular concentration to extracellular concentration ratio, > or = 2.2) or McCoy cells (intracellular concentration to extracellular concentration ratio, > or = 1.3). The uptake of fluconazole by PMNs was rapid and reversible but was not energy dependent. The intracellular penetration of fluconazole was not affected by environmental pH or temperature. Ingestion of opsonized zymosan and opsonized Candida albicans did not significantly increase the amount of PMN-associated fluconazole. At therapeutic extracellular concentrations, the intracellular activity of fluconazole against C. albicans in PMNs was significantly lower than that of amphotericin B. It was concluded that fluconazole reaches high intracellular concentrations within PMNs but shows moderate activity against intracellular C. albicans in vitro.

Amphotericin B↗
PubMed1993

[Comparison of 4 processing methods for the diagnosis of peritonitis in patients undergoing chronic ambulatory peritoneal dialysis].

BACKGROUND: Four methods for the diagnosis of peritonitis in patients submitted to chronic ambulatory peritoneal dialysis were evaluated. METHODS: Fluid from eighty-five patients undergoing peritoneal dialysis processed by the following techniques conventional, centrifugation, injection into conventional BACTEC bottles and in double volume BACTEC bottles. In addition, qualitative and quantitative counts of the number of leukocytes/mm3 of peritoneal dialysis, as well as the gram staining of the sediment obtained following centrifugation were carried out. RESULTS: Sixty-eight percent of the peritoneal dialysis fluid processed fulfilled criteria of peritonitis. Global sensitivity of the diagnostic techniques used was 62%. The sensitivities of the different methods were individually: conventional, 46%, centrifugation, 52%, injection into conventional BACTEC bottles, 53%, and injection into double volume BACTEC bottles 58%. Gram staining sensitivity was 9%. CONCLUSIONS: Direct injection of peritoneal dialysis in double volume BACTEC bottles is a useful technique for the etiologic diagnosis of peritonitis in patients submitted to chronic ambulatory peritoneal dialysis. In this study, its sensitivity was greater to that of the other methods evaluated allowing minimal handling and delay in the processing of the sample.

Ascitic Fluid↗
PubMed1993

[Ciprofloxacin resistance in gram negative bacilli. Epidemiologic aspects].

BACKGROUND: The aim of the present was to study the resistance to ciprofloxacin (CIP) in gram negative bacilli (April 1990-March 1992) and to determine the temporary distribution of the resistant strains by species, samples and departments. METHODS: Seven thousand four hundred seventy-eight samples were studied. The identification and determination of the sensitivity was performed by the PASCO (Difco) system. Haemophilus spp. and Campylobacter spp. were excluded from the study. The microorganisms with CIM 2 mg/l were considered as resistant (CIPr). RESULTS: Four hundred eighty-one CIPr isolations were identified (6.4%). With regard to the percentage of resistant strains, the species with the highest were: Providencia stuartii (50%); Pseudomonas cepacia (44.4%); Xanthomonas maltophilia (26.9%); Acinetobacter baumannii (25.8%); Pseudomonas aeruginosa (16%); Citrobacter freundii (12.5%); Serratia marcescens (8.4%); Enterobacter cloacae (5.8%) and Escherichia coli (4.3%). With respect to the absolute number of resistant strains, the most frequent resistant strains were: P. aeruginosa (205), E. coli (144), and A. baumannii (41). Isolation of E. coli and A. baumannii CIPr increased over the study period. Forty-four point five percent of the E. coli CIPr were of extrahospitalary origin; most of the A. baumannii (92.9%) and P. aeruginosa (77.6%) in contrast were of intrahospitalary origin. CONCLUSIONS: P. aeruginosa, E. coli, and A. baumannii are the most frequently resistant species. The frequency of isolation of resistant strains of E. coli and A. baumannii significantly increased (p < 0.001) over the two years of the study.

Ciprofloxacin↗
PubMed1993

[Resistance in Haemophilus influenzae in Spain. 2d study (1990)].

AIM: To study the resistance to strains of H. influenzae simultaneously isolated during 1990 in 10 Spanish cities with this being the second multicentric study carried out in Spain. METHODS: Three hundred eight strains of H. influenzae were consecutively isolated with less than 50% being from the respiratory tract. The sensitivity by microdilution in supplement Isosensitest was studied. RESULTS: Thirty-five percent of the strains were producers of beta-lactamase which predominate among those isolated in systemic infections and specially among those from Madrid (58.78%) and Barcelona (61.8%). The strains producing beta-lactamase were more resistant to all the antimicrobials than the non producers. Five point two percent of the strains were resistant to ampicillin by non enzymatic mechanisms. Resistance to chloramphenicol is frequent (28.6%) especially among strains producing beta-lactamase, strains of ocular origin and ORL (46%) and systemic infections (74.3%). The distribution is irregular, being more frequent in Seville (66.7%) and not detectable in Barcelona. Resistance to tetracycline is also usually linked to the production of beta-lactamase and not necessarily to that of chloramphenicol. Resistance to cotrimoxazole is the most frequent (67.5%) specially in Valladolid (87.5%). Resistance to cefaclor is of 60.7% being the most frequent among those isolated from ocular processes and ORL. Only 28 strains (9.1%) were sensitive to all the antimicrobials tested. Thirty-nine percent were multiresistant. CONCLUSIONS: The authors found a slight increase in the high resistance detected in 1986. This increase was not uniform in all of Spain being significant in Madrid with producers of beta-lactamase, in Seville to chloramphenicol, to tetracycline in Bilbao and cotrimoxazole in Valencia.

Bacterial Proteins↗
PubMed1992

Comparative penetration of lomefloxacin and other quinolones into human phagocytes.

The penetration of lomefloxacin into human polymorphonuclear leukocytes (PMNs) and peritoneal macrophages (PMphis) was evaluated using a fluorometric assay. Lomefloxacin reached high intracellular concentrations into PMNs at extracellular concentrations of 2 and 5 mg/L (cellular to extracellular concentration ratio [C/E] greater than 4). At the same conditions (20 minutes incubation; extracellular concentrations: 2 mg/L) lomefloxacin uptake by human PMNs (C/E: 7.9 +/- 2.6) was slightly higher than those of norfloxacin (C/E 5.1 +/- 1.8), ciprofloxacin (C/E: 6.2 +/- 2.0), and ofloxacin (C/E 7.1 +/- 2.6). Lomefloxacin penetration into human PMphis was significantly lower than PMNs but still with C/E ratios greater than 4. Entry of lomefloxacin into phagocytes was not affected by cell viability but was environmental-temperature dependent. It is concluded that lomefloxacin and the other quinolones evaluated reach high intracellular concentrations in human phagocytic cells.

Analysis of Variance↗
PubMed1992

Effect of several antimicrobial agents on ciprofloxacin uptake by human neutrophils.

The effect of antimicrobial agent active against anaerobes, gram-positive cocci and fungi on the uptake of ciprofloxacin by human neutrophils (PMNs) was evaluated. In the presence of therapeutic extracellular concentrations of these agents, ciprofloxacin reached high intracellular concentrations [cellular-to-extracellular ratio (C/E) greater than or equal to 2.9], this value being higher in the presence of amphotericin B (C/E 6.3 +/- 0.9). The intracellular penetration of ciprofloxacin was higher when PMNs were stimulated with opsonized zymosan (C/E greater than or equal to 5.6). In summary, none of the antimicrobial agents tested significantly impaired the uptake of ciprofloxacin by human PMNs.

Anti-Infective Agents↗
PubMed1992

Entry of lomefloxacin and temafloxacin into human neutrophils, peritoneal macrophages, and tissue culture cells.

The uptake of lomefloxacin (difluoroquinolone) and temafloxacin (trifluoroquinolone) by human polymorphonuclear leukocytes (PMNs), peritoneal macrophages (PM phis), and two tissue culture cells (McCoy and Vero) was measured by a fluorometric assay. Both antimicrobials reached high intracellular concentrations in PMNs [cellular to extracellular ratio (C/E) greater than 4], in PM phis (C/E greater than 3) and lower in tissue culture cells (C/E greater than 1) at an extracellular concentration of 5 mg/L. Lomefloxacin uptake by PMNs was more rapid than that of temafloxacin. Entry of both quinolones into PMNs was environmental temperature-dependent, but not affected by cell viability. Ingestion of opsonized Staphylococcus aureus did not affect the ability of PMNs to concentrate these antimicrobials. Ingestion of opsonized zymosan or stimulation with phorbol myristate acetate significantly increased the PMN association of both quinolones, this effect being particularly marked with temafloxacin. It is concluded that both lomefloxacin and temafloxacin are markedly concentrated within human phagocytes and tissue culture cells, although this phenomenon is not dependent on the degree of fluorination of the molecule.

Animals↗
PubMed1992

Uptake and intracellular activity of sparfloxacin in human polymorphonuclear leukocytes and tissue culture cells.

The penetration of sparfloxacin into human neutrophils (PMN) and different tissue culture cells (HEp-2 and McCoy) was evaluated. The cellular to extracellular concentration ratios (C/E) of sparfloxacin were always higher than 4 at extracellular concentrations ranging from 0.5 to 25 mg/liter. The uptake of sparfloxacin by PMN was rapid, nonsaturable, reversible, not energy dependent, and significantly reduced at pH 8. The penetration of this agent into PMN was similar when viable and Formalin-killed cells were used and was not affected by environmental temperature. Ingestion of opsonized zymosan significantly increased the amount of PMN-associated sparfloxacin. Sparfloxacin at a concentration of 0.5 mg induced a significant reduction in the survival of intracellular Staphylococcus aureus. It is concluded that sparfloxacin reaches intracellular concentrations within leukocytic cells much higher than extracellular concentrations, while remaining active intracellularly.

Anti-Infective Agents↗
PubMed1992

[Effect of cefepime on adhesion and phagocytosis of Pseudomonas aeruginosa].

BACKGROUND: We studied the effect of subinhibitory concentrations of cefepime on cell surface hydrophobicity expression and adherence to epithelial cells of Pseudomonas aeruginosa. We also evaluated the effect of this drug on the interaction between Pseudomonas aeruginosa and human polymorphonuclear leukocytes. METHODS: The bacterial cell surface hydrophobicity was tested on a biphasic system (water/p-xylene). The bacterial adherence to epithelial cells as well as the phagocytosis of Pseudomonas aeruginosa was studied using radiometric techniques. The superoxide production was evaluated by means of cytochrome C reduction method. RESULTS: Pre-incubation of a non mucoid Pseudomonas aeruginosa strain with a 0.25 MIC value of cefepime produces a reduction in the adherence of this microorganism to epithelial cells, but without modifying the surface hydrophobicity. Pre-incubation of a mucoid and a non mucoid P. aeruginosa strain with a 0.25 MIC value of cefepime reduces its phagocytosis by polymorphonuclear leukocytes. The preincubation polymorphonuclear leukocytes with cefepime (1, 10, and 100 mg/ml) did not influence the phagocytosis of Pseudomonas aeruginosa nor the bactericidal mechanisms of PMN (superoxide production). At therapeutic concentrations, cefepime showed intracellular activity against P. aeruginosa in human polymorphonuclear leukocytes. CONCLUSIONS: The incubation of Pseudomonas aeruginosa with sub-MIC inhibit its adherence to epithelial cells and its intake by human polymorphonuclear leukocytes. At therapeutic concentrations, cefepime did not affect the bactericidal mechanisms of polymorphonuclear leukocytes, and shows a significant intracellular activity against P. aeruginosa.

Bacterial Adhesion↗
PubMed1992

[High-pressure liquid chromatography versus a radiometric method in the identification of aminoglycoside-acetylating enzymes].

BACKGROUND: High Pressure Liquid Chromatography and a radiometric method for detecting and iso-enzyme identification of aminoglycoside-acetylation enzymes were compared. HPLC determines the acetylating activity of an enzyme by using its reaction product. MATERIAL AND METHODS: Three reference strains that produce AAC (3)-I, AAC (6')-IV and AAC (2') and 15 strains isolated from patients. Identification was performed using radiometric and HPLC method in all cases. RESULTS: References strains: The enzymes produced by these strains were correctly identified with HPLC. Patient's strains: All give positive acetylase screening results with the chromatographic method, with holding time peaks that allows the identification of at least three different compounds. Identification at isozyme level was possible in all cases. In 14 out of 15 strains the results were the same using either technique. Radiometric method could not identify the enzyme of one strain. CONCLUSION: HPLC is a useful technique for isoenzyme identification of aminoglycoside-acetylation enzymes. The results were easily interpreted when compared to those of radiometric method. The group identification was possible with sisomycin.

Acetylation↗
PubMed1991

Fluorometric and high-performance liquid chromatographic measurement of quinolone uptake by human neutrophils.

A fluorometric assay, based on the natural fluorescence of the quinolone nucleus, and high-performance liquid chromatography (HPLC) were compared to determine the penetration of six quinolones (norfloxacin, ciprofloxacin, ofloxacin, fleroxacin, lomefloxacin and temafloxacin) into human polymorphonuclear neutrophils (PMN). Intracellular concentrations after 20 min incubation of the cells with 10 and 25 mg/l were three or more times higher than the extracellular ones. There were no statistical differences between the two methods. At lower extracellular concentrations (2 and 5 mg/l) the intracellular levels of all the quinolones tested were undetectable by HPLC. Fluorometry is a useful method for determining the intracellular penetration of quinolones. The usefulness of HPLC, however, is questionable since it requires great volumes of cells and extracellular concentrations much higher than the therapeutic ones.

Anti-Infective Agents↗