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E H Gerlach

Publications and source records attributed to E H Gerlach.

At least 37 records · Page 2Linked to original sources
PubMed1992

MIC and disk diffusion quality control guidelines for Neisseria gonorrhoeae susceptibility tests of cefdinir, cefetamet, CI-960, fleroxacin, lomefloxacin, and temafloxacin.

Cefdinir (FK482), cefetamet (Ro 15-8074), CI-960, fleroxacin, lomefloxacin, and temafloxacin have potent activities against Neisseria gonorrhoeae. They were tested in a multilaboratory study to establish quality control guidelines. Quality control ranges for N. gonorrhoeae ATCC 49226 were determined by using multiple GC agar lots, three disk lots, and a number of test replicates consistent with the M23-T guidelines of the National Committee for Clinical Laboratory Standards. The MIC ranges included 2 to 4 log2 dilution steps. The recommended inhibition zone diameter ranges were generally 7 to 8 mm and included greater than or equal to 91.3% of all recorded study results.

Anti-Infective Agents↗
PubMed1991

Antimicrobial activity of RU29246 (HR916 metabolite) compared with four other oral beta-lactams tested against more than 5000 clinical isolates.

The activity of RU29246, the active metabolite of the oral cephalosporin ester HR916, was compared in a multicenter study with that of the four oral beta-lactam antibiotics cephalexin, cefaclor, cefixime and amoxicillin/clavulanate (amoxicillin/CA). RU29246 was generally 2- to 8-fold more active than the other oral cephalosporins and comparable to amoxicillin/CA against staphylococci, and was the most active cephalosporin against group B streptococci. All four cephalosporins were ineffective against enterococci. RU29246 was the only cephalosporin consistently active against Acinetobacter, but all beta-lactam antibiotics had poor activity against Pseudomonas spp. and Xanthomonas maltophilia. RU29246 was comparable to cefixime and more active than the other cephalosporins against members of the family Enterobacteriaceae. However, all of the antibiotics had poor activity against Enterobacter cloacae and Serratia marcescens. Quality control reference ranges for the quality control organisms Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 are proposed for the broth dilution method based on data derived from this multicenter study.

Amoxicillin↗
PubMed1991

Multicenter evaluation of the in vitro activities of three new quinolones, sparfloxacin, CI-960, and PD 131,628, compared with the activity of ciprofloxacin against 5,252 clinical bacterial isolates.

The in vitro activities of three new quinolones (sparfloxacin, CI-960, and PD 131,628) were compared with that of ciprofloxacin against 5,252 routine clinical aerobic and facultatively anaerobic bacterial isolates. Overall, CI-960 was the most active drug in vitro (MIC for 90% of the strains tested, 0.13 micrograms/ml); ciprofloxacin and sparfloxacin were the least active (MIC for 90% of the strains tested, 1.0 micrograms/ml). All three new quinolones, but particularly CI-960 and PD 131,628, exhibited significantly greater activity than ciprofloxacin against enterococci and staphylococci.

Anti-Infective Agents↗
PubMed1991

In vitro comparison of GR69153, a novel catechol-substituted cephalosporin, with ceftazidime and ceftriaxone against 5,203 recent clinical isolates.

The activity of GR69153, a novel catechol-substituted cephalosporin, was compared with those of ceftazidime and ceftriaxone in a multicenter study against 5,203 fresh clinical isolates of gram-negative and gram-positive bacteria. GR69153 was generally very active at concentrations equivalent to or two- to fourfold lower than those of ceftazidime and ceftriaxone against gram-negative bacilli other than Citrobacter freundii, Enterobacter cloacae, and Xanthomonas maltophilia. Against Pseudomonas aeruginosa, MICs of GR69153 and ceftazidime for 50% of isolates tested (MIC50s) were, respectively, 1 and 2 micrograms/ml; the corresponding MIC90s were 4 and 16 micrograms/ml. Although MIC50s of GR69153 for staphylococci were two- to eightfold lower than those of ceftazidime or ceftriaxone, MIC90s against staphylococci and enterococci were greater than or equal to 16 micrograms/ml for all three compounds. Quality control MIC ranges for reference strains are proposed for the broth microdilution method on the basis of the GR69153 data derived from this multicenter study.

Bacteria↗
PubMed1991

Interpretive criteria and quality control guidelines for Neisseria gonorrhoeae susceptibility test standardization for cefotetan.

Cefotetan was tested in a multilaboratory study to standardize susceptibility testing criteria and quality control guidelines for Neisseria gonorrhoeae. Cefotetan was most active against penicillinase-producing and penicillin-susceptible strains (MIC for 50% of strains tested, 0.5 micrograms/ml) and was least active against the chromosomally resistant isolates (MIC for 50% of strains tested, 2 micrograms/ml). The recommended 30-micrograms disk cefotetan interpretive criteria were as follows: susceptible at greater than or equal to 26 mm (less than or equal to 2 micrograms/ml), intermediate at 20 to 25 mm (4 micrograms/ml), and resistant at less than or equal to 19 mm (greater than or equal to 8 micrograms/ml). Quality control guidelines for agar dilution and disk diffusion tests were established by using numerous GC agar lots, three cefotetan 30-micrograms disk lots, two quality control organisms, and a volume of tests consistent with National Committee for Clinical Laboratory Standards M23-T guidelines.

Cefotetan↗
PubMed1990

Sucralfate significantly reduces ciprofloxacin concentrations in serum.

The effect of sucralfate on the bioavailability of ciprofloxacin was evaluated in eight healthy subjects utilizing a randomized, crossover design. The area under the concentration-time curve from 0 to 12 h was reduced from 8.8 to 1.1 micrograms.h/ml by sucralfate (P less than 0.005). Similarly, the maximum concentration of ciprofloxacin in serum was reduced from 2.0 to 0.2 micrograms/ml (P less than 0.005). We conclude that concurrent ingestion of sucralfate significantly reduces the concentrations in serum produced by a 500-mg dose of ciprofloxacin. On the basis of these findings, ciprofloxacin and sucralfate should not be administered concurrently.

Adult↗
PubMed1989

Multicenter in vitro evaluation of SM-7338, a new carbapenem.

A new carbapenem, SM-7338, was compared with imipenem, cefotaxime, and ceftazidime at five medical centers. Nearly 6,000 strains were tested by reference methods of the National Committee for Clinical Laboratory Standards, and SM-7338 inhibited the largest percentage of gram-negative bacilli. Its spectrum included all members of the family Enterobacteriaceae (99.7% were susceptible to less than or equal to 4 micrograms/ml), Pseudomonas spp. (but not Xanthomonas maltophilia), and Acinetobacter spp. The potency and spectrum of SM-7338 against the gram-positive organisms were less than those of imipenem and superior to those of ceftazidime. Only the enterococci and some oxacillin-resistant staphylococci were less susceptible to SM-7338 (MICs for 90% of isolates, greater than or equal to 8 micrograms/ml). Organisms resistant to ceftazidime were generally susceptible to SM-7338 and imipenem (76%). However, for one-third of the imipenem-resistant gram-negative bacilli (MICs, greater than 8 micrograms/ml), SM-7338 MICs were less than or equal to 4 micrograms/ml. Some endemic differences in patterns of SM-7338 activity against selected gram-negative species were found among some medical centers.

Anti-Bacterial Agents↗
PubMed1989

Quality control guidelines for testing cefotetan in the reference agar dilution procedure for susceptibility testing of anaerobic bacteria.

Reference values for quality control of in vitro susceptibility tests with cefotetan against anaerobic bacteria were determined in two independent multilaboratory studies with the approved National Committee for Clinical Laboratory Standards agar dilution method and three control strains (Bacteroides fragilis ATCC 25285, Bacteroides thetaiotaomicron ATCC 29741, and Clostridium perfringens ATCC 13124). The results of the two studies were in agreement. The recommended MIC control limits for B. fragilis ATCC 25285 and B. thetaiotaomicron ATCC 29741 are 4.0 to 16 micrograms/ml and 32 to 128 micrograms/ml, respectively. MICs for C. perfringens ATCC 13124 were too variable to be useful for controlling tests with cefotetan.

Bacteria, Anaerobic↗
PubMed1989

Quality control limits for the standard anaerobic reference agar dilution susceptibility test procedure of the National Committee for Clinical Laboratory Standards.

Multilaboratory studies were performed to develop MIC quality control limits for the National Committee for Clinical Laboratory Standards reference agar dilution method for anaerobic susceptibility tests. Acceptable MICs were defined as those which include greater than 95% of all 100 MICs generated by the study. Most MIC control limits included either 2- or 3-dilution intervals rather than the more traditional 3-dilution intervals that are described as the mode +/- 1 doubling dilution.

Amoxicillin↗
PubMed1989

Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline.

A six-laboratory study developed a standardized method for determining the susceptibilities of Neisseria gonorrhoeae strains to penicillin, tetracycline, spectinomycin, and ceftriaxone. Three quality control organisms were also selected, and quality assurance guidelines were initially generated for the disk diffusion and agar dilution methods. The medium recommended for gonococcal susceptibility testing was GC agar with a defined "XV-like" supplement. The supplement should be free of cysteine, a component implicated in the inactivation of some newer beta-lactam compounds. Penicillin, tetracycline, spectinomycin, and ceftriaxone were stable in agar plates stored at 3 to 5 degrees C for at least 2 weeks. Numerous GC agar and drug disk lots were used during the trials without significant variation in test results. Several other gonococcal strains were recommended for additional medium quality assurance. The disk quality control zone limits were established for N. gonorrhoeae ATCC 49226 (formerly CDC F-18) and Staphylococcus aureus ATCC 25923. MIC quality control ranges were also developed for N. gonorrhoeae ATCC 49226 and S. aureus ATCC 29213. The interpretive criteria for penicillin were as follows: susceptibility, greater than or equal to 47 mm (diameter of inhibition zone) (less than or equal to 0.06 micrograms/ml [MIC]); resistance, less than or equal to 26 mm (greater than or equal to 2 micrograms/ml). For tetracycline they were as follows: susceptibility, greater than or equal to 38 mm (less than or equal to 0.25 microgram/ml); resistance, less than or equal to 30 mm (greater than or equal to 2 micrograms/ml). For spectinomycin they were as follows: susceptibility, >/= 18 mm (</= 32 micrograms/ml); resistance, </= 14 mm (>/= 128 micrograms/ml). For ceftriaxone susceptibility, the criterion was >/= 35 mm (</= 0.25 micrograms/ml) with no other category. Criteria of </= 19 mm for plasmid-mediated resistances to penicillin and tetracycline were also confirmed. The false-susceptibility errors were </= 1% with these criteria.

Ceftriaxone↗
PubMed1988

In vitro activity of FCE 22101, imipenem, and ceftazidime against over 6,000 bacterial isolates and MIC quality control limits of FCE 22101.

Six geographically separate laboratories within the USA tested 6,198 bacterial isolates against FCE 22101 (a penem), imipenem (a carbapenem) and ceftazidime (a third-generation cephalosporin). Ninety-three percent of 2,749 Enterobacteriaceae were inhibited by FCE 22101, while 95% were susceptible to ceftazidime and 99% were susceptible to imipenem. FCE 22101 had little activity against Pseudomonas spp. but was active against most gram-positive pathogens, including enterococci. FCE 22101 MICs for standard quality control strains were defined as 0.5-2.0 micrograms/ml for Escherichia coli ATCC 25922, 2-8 micrograms/ml for Enterococcus faecalis ATCC 29212 and 0.06-0.25 microgram/ml for Staphylococcus aureus ATCC 29213.

Anti-Bacterial Agents↗
PubMed1988

Effect of clavulanic acid on the susceptibility of clinical anaerobic bacteria to ticarcillin: a multicenter study.

Over 2,000 recent clinical isolates of anaerobic bacteria were tested at five medical centers for susceptibility to ticarcillin, ticarcillin plus clavulanic acid, clindamycin, and metronidazole. At 64 micrograms/ml, ticarcillin inhibited 92% of all isolates, but 98% were inhibited at this concentration when 2 micrograms/ml of clavulanic acid was added. With different Bacteroides species, clavulanic acid reduced ticarcillin MICs 2- to 32-fold; other anaerobic species were not significantly affected.

Bacteria, Anaerobic↗
PubMed1988

Multicenter in vitro evaluation of lomefloxacin (NY-198, SC-47111), including tests against nearly 7,000 bacterial isolates and preliminary recommendations for susceptibility testing.

Lomefloxacin (NY-198 or SC-47111) is a difluoro-quinolone derivative having a C-methyl at the 3-position of the piperazine ring, thus minimizing its metabolic alteration in vivo. In our research, its antimicrobial activity was most similar to that of difloxacin, enoxacin, fleroxacin, and norfloxacin but usually less than that of ciprofloxacin and ofloxacin against most species. Lomefloxacin shared cross-resistance with other 4-quinolones but remained very active against ceftazidime-resistant organisms, including stably derepressed beta-lactamase producing Gram-negative bacilli. Lower pH increased the lomefloxacin MICs. MBCs were usually identical to the measured MIC, and the lomefloxacin MICs were not significantly increased by high inoculum concentrations. The Enterobacteriaceae were found to have a very low rate of spontaneous mutation to lomefloxacin resistance (10(-8)-10(-9). In vitro tests by 5-micrograms and 10-micrograms lomefloxacin disks and dilution methods were correlated, and the 10-micrograms disk was recommended for clinical trials using a less than or equal to 4 micrograms/ml susceptible breakpoint. The quality assurance guidelines for dilution tests were determined by a multilaboratory study.

4-Quinolones↗
PubMed1988

Optimal cefotaxime dosing for gram-negative bacteremia: effective trough serum bactericidal titers and drug concentrations 8 and 12 hr after 1- or 2-gm infusions.

Thirteen adult patients (47-81 yr) with gram-negative bacteremia and normal (less than or equal to 1.5 mg/dl) serum creatinines were treated with 1 or 2 gm of cefotaxime every 8 or 12 hr. The infecting organisms were Escherichia coli (9 strains), Klebsiella pneumoniae (2 strains), and one isolate of Salmonella enteritidis and Serratia marcescens. All patients recovered without any serious sequelae. The range of MICs for cefotaxime and desacetyl-cefotaxime were 0.015-0.25 micrograms/ml and 0.015-4.0 micrograms/ml, respectively. The MBC values for cefotaxime and desacetyl-cefotaxime were identical to the MIC values except for two strains. The trough levels of cefotaxime varied from 65.9 to 1.1 micrograms/ml. The serum concentration of desacetyl-cefotaxime varied from 84 to less than 1.0 microgram/ml. All corresponding trough serum inhibitory activities (SIA) were greater than or equal to 1:32. Comparisons of calculated and directly measured serum bactericidal activity (SBA) and SIA results suggest an additive and occasional synergistic benefit of the cefotaxime desacetyl metabolite. This study supports the clinical efficacy and cost-effectiveness of 8- and 12-hr dosing intervals for cefotaxime against bacteremic gram-negative strains having the usual high susceptibility (MICs, less than or equal to 0.25 micrograms/ml) to the newer cephalosporins.

Aged↗
PubMed1987

CI-934, a new difluoroquinolone: in vitro antibacterial activity and proposed disk diffusion test interpretive criteria.

The susceptibility of 7,763 clinical isolates at four medical centers to CI-934 and three comparative quinolones was tested. CI-934 was the most active compound against Gram-positive isolates, such as staphylococci (MIC 90 = 0.25 microgram/ml), and enterococci (MIC 90 = 0.5 microgram/ml). CI-934 was the least active of these drugs against Pseudomonas spp. (MIC 90 = greater than 8.0 micrograms/ml). Against all other organisms CI-934 was very effective, being most comparable with enoxacin. With a selected group of isolates, CI-934 demonstrated high activity against Haemophilus influenzae (MIC 90 = 0.06 microgram/ml), Neisseria meningitidis and N. gonorrhoeae (MIC 90 = 0.13 microgram/ml), Listeria monocytogenes (MIC 90 = 1.0 microgram/ml), methicillin-resistant staphylococci (MIC 90 = 0.13 microgram/ml), and modest activity against anaerobes. Disk diffusion susceptibility testing of CI-934 was evaluated using 3-, 5-, and 10-micrograms disks. Because of its lower interpretive error rate, the 3-micrograms disk is tentatively recommended. With less than or equal to 2 micrograms/ml and greater than 4 micrograms/ml as the susceptible and resistant MIC breakpoints, the corresponding 3-micrograms disk zone diameters breakpoints are greater than or equal to 15 mm and less than or equal to 11 mm. Because most isolates of Pseudomonas spp. are not susceptible to CI-934 and the zone size interpretive error rate is particularly high (33%) with Pseudomonas spp., we suggest that isolates of this genus not be tested for clinical purposes.

Anti-Bacterial Agents↗
PubMed1987

Antimicrobial activity of Ro 19-5247 (T-2525), a new oral cephalosporin, tested against 7,745 recent clinical isolates.

The susceptibility testing of 7,745 recent clinical isolates from four medical centers showed Ro 19-5247 to be eight- to greater than 64-fold more active than cephalexin against the Enterobacteriaceae. Ro 19-5247 was comparable with cephalexin in anti-staphylococcal activity (MIC50, 4.0 micrograms/ml) and fourfold more active than cefixime. None of the oral cephalosporins were effective (MIC50, greater than 32 micrograms/ml) against enterococci, Pseudomonas aeruginosa and P. maltophilia. beta-lactamase hydrolysis experiments failed to demonstrate significant Ro 19-5247 inactivation by ten commonly encountered chromosomal- or plasmid-mediated enzymes (P99, K1, K14, TEM, CARB, OXA).

Bacteria↗