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P C Fuchs

Publications and source records attributed to P C Fuchs.

At least 91 records · Page 5Linked to original sources
PubMed1995

Antibacterial activity of WY-49605 compared with those of six other oral agents and selection of disk content for disk diffusion susceptibility testing.

The in vitro antimicrobial activity of an oral penem, WY-49605, was compared with those of six other oral antimicrobial agents against 598 bacterial isolates representing 51 different species. WY-49605 exhibited good activity against most gram-positive bacteria and members of the family Enterobacteriaceae. It had little activity against nonfermenting gram-negative bacilli, Enterobacter spp., Serratia spp., enterococci, Staphylococcus haemolyticus, and methicillin-resistant Staphylococcus aureus. Its activity was unaffected by the beta-lactamases of Neisseria gonorrhoeae, Haemophilus influenzae, and staphylococci. Disk diffusion susceptibility tests were performed with 5-, 10-, 15-, and 30-micrograms WY-49605 disks. The 5-micrograms disk is recommended, with tentative breakpoints of > or = 16 mm for susceptibility (MIC, < or = 2.0 microgram/ml) and < or = 12 mm for resistance (MIC, > or = 8.0 micrograms/ml).

Anti-Bacterial Agents↗
PubMed1995

Interpretive criteria and quality control parameters for testing bacterial susceptibility to the fluoroquinolone PD131628.

For testing bacterial susceptibility to PD131628, a 5-micrograms disk and the following tentative interpretive criteria may be used: > or = 19 mm for susceptible (MIC, < or = 1.0 micrograms/ml), 16 to 18 mm for intermediate (MIC, 2.0 micrograms/ml), and < or = 15 mm for resistant (MIC, > or = 4.0 micrograms/ml). For standard quality control strains, the following limits are proposed: for Escherichia coli ATCC 25922, zones of 31 to 41 mm or a MIC of 0.002 to 0.016 micrograms/ml; for Pseudomonas aeruginosa ATCC 27853, zones of 26 to 34 mm or a MIC of 0.12 to 0.5 micrograms/ml; for Staphylococcus aureus ATCC 25923, zones of 27 to 33 mm; for Staphylococcus aureus ATCC 29213, a MIC of 0.03 to 0.12 micrograms/ml; and for Enterococcus faecalis ATCC 29212, a MIC of 0.12 to 0.5 micrograms/ml.

Anti-Infective Agents↗
PubMed1995

Methods for predicting susceptibility of Streptococcus pneumoniae to cefixime.

Among 698 Streptococcus pneumoniae isolates, 475 were penicillin susceptible and > 99% of those were susceptible to 0.5 microgram of cefixime per ml; other pneumococci were tentatively assumed to be resistant to cefixime. A 1-microgram oxacillin disk was more reliable than a 5-micrograms cefixime disk for predicting susceptibility to cefixime.

Cefixime↗
PubMed1994

Prosthetic valve endocarditis: superiority of surgical valve replacement versus medical therapy only.

The objective of our study was to assess the long-term outcome of patients with prosthetic valve endocarditis. We used a multicenter, prospective, observational study design. Six university teaching hospitals with high volume cardiothoracic surgery participated. Seventy-four patients with prosthetic valve endocarditis as defined by explicit, objective criteria were selected for participation. All patients were followed up prospectively for 1 year. Thirty-one percent and 69% had development of endocarditis within 60 days of valve insertion ("early") and after 60 days ("late"), respectively. The most common causes were Staphylococcus epidermidis (40%), Staphylococcus aureus (20%), streptococcal species (18%), and aerobic gram-negative bacilli (11%). Physical signs of endocarditis (new or changing murmur, stigmata, emboli) were seen in 58%. At 6 months and 12 months, mortality was 46% and 47%, respectively. Surgical replacement of the infected valve led to significantly lower mortality (23%) as compared with medical therapy alone (56%), as assessed by both univariate and multivariate analyses (p < 0.05). Improved outcome was seen for the surgical group even when controlling for severity of illness at time of diagnosis. From these findings we conclude that accurate assessment of outcome in prosthetic valve endocarditis requires long-term follow-up of at least 6 months following diagnosis. Surgical therapy warrants greater scrutiny; evaluation in controlled clinical trials is appropriate.

Adult↗
PubMed1994

Comparison of identification systems for Staphylococcus epidermidis and other coagulase-negative Staphylococcus species.

Three commercially available systems (API Staph-Trac, API 20GP, and Vitek GPI), used to identify coagulase-negative staphylococci, were evaluated against 277 bloodstream isolates, including 94 isolates of Staphylococcus epidermidis and 183 isolates of other coagulase-negative Staphylococcus species. The conventional method of Kloos and Schleifer served as the reference method. Controls included 14 ATCC type culture strains of coagulase-negative staphylococci. The API Staph-Trac system showed the highest rate of agreement with reference method, correctly identifying 73% of the isolates. The Vitek GPI System had an overall rate of agreement of 67% and the API 20GP system correctly identified 61%. The API Staph-Trac system correctly identified 94% of the isolates of S. epidermidis compared with 64% by both Vitek GPI and API 20GP. The most common error for both Vitek GPI and API 20GP systems was the failure to identify organisms contained within the database of the systems. Because none of the tested commercial identification systems identified "non-epidermidis" coagulase-negative Staphylococcus species with a high degree of accuracy, the systems need to be markedly improved or new systems developed.

Bacteremia↗
PubMed1994

In-vitro activity of five beta-lactam/beta-lactamase inhibitor combinations against consecutive isolates of the Enterobacteriaceae and Pseudomonas aeruginosa.

Susceptibility tests were performed on 2402 of consecutive isolates of Enterobacteriaceae and 254 strains of Pseudomonas aeruginosa in five separate medical centres. Five beta-lactams were evaluated with and without a beta-lactamase inhibitor. The effect of different inhibitors was species specific and the rank order of decreasing efficacy against all enteric bacilli was: cefoperazone-sulbactam > piperacillin-tazobactam > cefoperazone > ticarcillin-clavulanic acid > piperacillin > co-amoxiclav > ampicillin-sulbactam > ticarcillin > ampicillin > amoxycillin.

Anti-Bacterial Agents↗
PubMed1994

Antibacterial activity of PD 131628 and proposed disc diffusion susceptibility test criteria.

The antibacterial activity of PD 131628 was compared with that of ciprofloxacin against 401 clinical isolates. The two drugs had comparable MICs for most Gram-negative species. PD 131628 was two to eight times more active against Gram-positive species and against Xanthomonas maltophilia. Both drugs were bactericidal, Among Gram-positive isolates, resistant mutants were not detected in vitro. Among Gram-negative bacilli, spontaneously occurring mutants resistant to PD 131628 were readily demonstrated more frequently than for ciprofloxacin. Resistance to PD 131628 was more readily induced by serially transferring the Gram-negative species, and resistant organisms emerged more rapidly on prolonged incubation in time-kill studies. Correlating the PD 131628 5 micrograms disc diffusion zone diameters with PD 131628 MICs, the following breakpoints are tentatively proposed: susceptible, MIC < or = 1 mg/L or zone > or = 19 mm; intermediate, MIC 2.0 mg/L or zones 16-18 mm; and resistant, MIC > or = 4.0 mg/L or zones < or = 15 mm.

Anti-Infective Agents↗
PubMed1994

In vitro activities of 12 orally administered antimicrobial agents against four species of bacterial respiratory pathogens from U.S. Medical Centers in 1992 and 1993.

Clinical isolates of Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus pyogenes, and Moraxella catarrhalis were gathered from 19 different clinical laboratories throughout the continental United States. The in vitro activities of 12 orally administered antimicrobial agents were compared by broth microdilution tests with 3,151 bacterial isolates. Among 890 H. influenzae isolates, 30% were capable of producing beta-lactamase enzymes (12 to 41% in different medical centers). Most of the 619 beta-lactamase-negative H. influenzae strains were susceptible to ampicillicin (MIC, < or = 1.0 micrograms/ml): 5 strains were intermediate in susceptibility (MIC, 2.0 micrograms/ml) and 1 strain was ampilicillin resistant (MIC, 4.0 micrograms/ml). Ninety-two percent of 698 M. catarrhalis strains were beta-lactamase positive. Of 799 S. pneumoniae isolates, 15% were intermediate in susceptibility to penicillin and 7% were resistant to penicillin. The prevalence of penicillin-susceptible pneumococci in different institutions ranged from 63 to 95%. Only 1% of 764 S. pyogenes isolates were resistant to the macrolides, but 5% of S. pneumoniae isolates were macrolide resistant. Only 71% of 58 penicillin-resistant S. pneumoniae isolates were erythromycin susceptible, whereas 97% of the 622 penicillin-susceptible strains were erythromycin susceptible. Penicillin-resistant pneumococci were also relatively resistant to the cephalosporins and amoxicillin. Penicillin-susceptible pneumococci were susceptible to amoxicillin-clavulanic acid (MIC for 90% of isolates tested [MIC90], < or = 0.12/0.06 microgram/ml), cefixime (MIC90, 0.25 microgram/ml), cefuroxime axetil (MIC90, < or = 0.5 microgram/ml), cefprozil (MIC90, < or = 0.5 micrograms/ml), cefaclor (MIC90, 0.5 microgram/ml), and loracarbef (MIC90, 1.0 microgram/ml). Most strains of the other species remained susceptible to the study drugs other than amoxicillin.

Administration, Oral↗
PubMed1994

Interpretive criteria for susceptibilities of Haemophilus influenzae to ampicillin, amoxicillin, and amoxicillin-clavulanic acid.

One hundred fifty isolates of Haemophilus influenzae (including 30 beta-lactamase-positive strains and 23 beta-lactamase-negative, ampicillin-resistant strains) were tested for susceptibilities to ampicillin, amoxicillin, and amoxicillin-clavulanic acid (A/C) by the broth microdilution method in Haemophilus test medium (HTM) and in Mueller-Hinton medium with lysed horse blood and by the disk diffusion method on HTM agar. Our results support the use of HTM for susceptibility testing of H. influenzae but raise a number of questions regarding the interpretive criteria currently in use, particularly with respect to the fourfold difference in MIC susceptibility breakpoints for ampicillin and A/C and a resulting high proportion of A/C-susceptible beta-lactamase-negative, ampicillin-resistant strains.

Amoxicillin↗
PubMed1994

Sudden death in a young athlete due to an anomalous commissural origin of the left coronary artery, and focal intimal proliferation of aortic valve leaflet at the adjacent commissure.

Sudden death occurred in a 15-year-old female athlete with an unusual anomalous left coronary artery. The left coronary artery origin was at (below) the commissure between the left and noncoronary aortic valve cusps. The ostium was slitlike and had an aortic ridge superiorly. In addition, there was an anomalous moundlike intimal proliferation of the noncoronary leaflet adjacent to the left coronary ostium that may have been an additional factor contributing to obstruction of coronary blood flow during diastole.

Adolescent↗
PubMed1993

Prosthetic valve endocarditis resulting from nosocomial bacteremia. A prospective, multicenter study.

OBJECTIVE: To determine the incidence of endocarditis in bacteremic patients with prosthetic heart valves and the risk factors for and the effect of duration of antibiotic therapy on development of endocarditis in such patients. DESIGN: Multicenter, prospective observational study. SETTING: Six university teaching hospitals with high-volume cardiothoracic surgery. PARTICIPANTS: One hundred seventy-one consecutive patients with prosthetic heart valves who developed bacteremia during hospitalization. MEASUREMENTS AND MAIN RESULTS: Patients were evaluated when they were identified as having bacteremia and 1, 2, 6, and 12 months after its occurrence. Of 171 patients, 74 (43%) developed endocarditis: Fifty-six (33%) had prosthetic valve endocarditis at the time bacteremia was discovered ("endocarditis at outset"), whereas 18 (11%) developed endocarditis a mean of 45 days after bacteremia was discovered ("new endocarditis"). Mitral valve location and staphylococcal bacteremia (Staphylococcus aureus or S. epidermidis) were significantly associated with the development of "new" endocarditis. All 18 cases of new endocarditis were nosocomial, and in 6 of these cases (33%) bacteremia was acquired via intravascular devices. Twenty-one patients without evidence of endocarditis at the time of bacteremia received short-term antibiotic therapy (< 14 days); 1 patient (5%) developed endocarditis. Eleven of 70 patients (16%) who received long-term antibiotic therapy (> 14 days) developed endocarditis (P > 0.2). CONCLUSIONS: Bacteremic patients with prosthetic heart valves were at notable risk for developing endocarditis, even when they received antibiotic therapy before endocarditis developed and regardless of the duration of such therapy. Intravascular devices were a common portal of entry.

Adult↗
PubMed1993

Selection of a fluoroquinolone-class disk for susceptibility tests.

A study was conducted to select a fluoroquinolone disk that could be used to represent other members of the fluoroquinolone class of drugs for routine susceptibility testing in the laboratory. Eight different fluoroquinolone agents were tested by disk diffusion and broth microdilution methods using 185 bacterial isolates, including 60 Enterobacteriaceae, 50 Pseudomonas species, 45 other gram-negative bacilli, and 30 Staphylococcus aureus. False-susceptible and false-resistant test results occurred at rates of 0-10% when disks containing different agents were tested against this unusually resistant collection of isolates. Much lower error rates would be expected with the type of microorganisms routinely encountered in clinical laboratories. Pefloxacin, enoxacin, or ciprofloxacin disks were not useful as class representatives. However, amifloxacin, lomefloxacin, ofloxacin, temafloxacin, or fleroxacin disks could be used to represent the other fluoroquinolones for routine susceptibility testing with a minimal chance of incurring serious errors.

Anti-Infective Agents↗
PubMed1993

In vitro activity of ceftriaxone and other cephalosporins against 602 clinical isolates of staphylococci from geographically diverse medical centers.

The in vitro activity of ceftriaxone and six additional antimicrobial agents (ceftizoxime, cefoperazone, cefuroxime, fleroxacin, ciprofloxacin, and trimethoprim/sulfamethoxazole) was assessed or 602 recent clinical isolates of staphylococci from six geographically distinct medical centers in North America. All seven antimicrobial agents were active (90-100% of strains susceptible) against oxacillin-susceptible (OS) strains of Staphylococcus aureus (OSSA) and coagulase-negative staphylococci (OSCNS) but had limited activity against oxacillin resistant (OR) staphylococci. Our assessment of the in vitro antistaphylococcal activity of ceftriaxone against contemporary isolates of Staphylococcus aureus and coagulase-negative staphylococci indicates that the activity versus OS staphylococci has not changed over the past decade despite widespread use of the drug. It appears that these agents will continue to be useful for empiric therapy in those centers in which OR strains are uncommon.

Academic Medical Centers↗
PubMed1993

Interpretive criteria and quality control parameters for determining bacterial susceptibility to fosfomycin tromethamine.

Studies with fosfomycin tromethamine disks containing 200 micrograms of fosfomycin and 50 micrograms of glucose-6-phosphate confirmed the following zone diameter criteria for the NCCLS method: < or = 12 mm for resistant (MIC > or = 256 micrograms/ml), 13-15 mm for intermediate (MIC 128 micrograms/ml) and > or = 16 mm for susceptible (MIC < or = 64 micrograms/ml). Additional studies defined acceptable MIC and zone diameter ranges for the following quality control strains: Escherichia coli ATCC 25922, MIC 0.5 to 4.0 micrograms/ml, zone diameter 23 to 29 mm; Staphylococcus aureus ATCC 25923, zone diameter 26 to 32 mm; Pseudomonas aeruginosa ATCC 27813, MIC 2.0 to 8.0 micrograms/ml; and Enterococcus faecalis, ATCC 29212, MIC 16 to 64 micrograms/ml.

Bacteria↗
PubMed1993

Comparison of fixed concentration and fixed ratio options for dilution susceptibility testing of gram-negative bacilli to ampicillin and ampicillin/sulbactam.

Ampicillin combined with sulbactam was tested at both fixed ratio (2:1 and 1:1) and fixed sulbactam concentrations (4 micrograms/ml, 8 micrograms/ml and 16 micrograms/ml) against 2440 consecutively isolated gram-negative bacilli. Sulbactam significantly enhanced the spectrum of ampicillin activity. Overall, at 8 micrograms/ml ampicillin inhibited 50% of the Enterobacteriaceae isolates, whereas 69% to 84% of the isolates were inhibited by the various sulbactam combinations. The widest spectrum of activity for ampicillin/sulbactam was achieved by testing at a fixed sulbactam concentration of 16 micrograms/ml, followed by the 1:1 ratio and the fixed 8 micrograms/ml (84%, 76% and 74% inhibited, respectively). The amount of sulbactam at the susceptible breakpoint concentrations of ampicillin markedly affected the percentage of susceptible strains. Combinations that include 8 micrograms/ml of sulbactam are suggested for consideration.

Ampicillin↗