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Biomedical subjects

G Kahlmeter

Publications and source records attributed to G Kahlmeter.

At least 37 records · Page 2Linked to original sources
PubMed2000

The ECO.SENS Project: a prospective, multinational, multicentre epidemiological survey of the prevalence and antimicrobial susceptibility of urinary tract pathogens--interim report.

The ECO.SENS Project is the first international survey to investigate the prevalence and susceptibility of pathogens causing community-acquired, uncomplicated urinary tract infections (UTIs) in women. At 240 centres in 17 countries, female patients presenting with symptoms of uncomplicated UTIs were asked to provide a urine sample for testing for the presence of leucocytes and bacteria. The bacteria were identified and their susceptibility to 12 antibiotics commonly used in the treatment of UTIs was determined. The objective of the survey was to collect 5000 urine samples to obtain approximately 3500 isolates of defined uropathogens. This interim report includes the results from 1960 urine samples, 75% of which contained a uropathogen. Escherichia coli accounted for the majority (80%) of uropathogens isolated in all 17 countries. The rates of resistance among E. coli strains were: ampicillin and sulphamethoxazole, 30%; trimethoprim alone or with sulphamethoxazole, 15%; nalidixic acid, 6%; ciprofloxacin, 3%; amoxycillin-clavulanic acid, mecillinam, cefadroxil, nitrofurantoin and fosfomycin, < or =2%. The use of ampicillin, sulphonamides and trimethoprim alone or with sulphamethoxazole needs to be reconsidered. The seemingly rapid increase in quinolone resistance among community-acquired E. coli in some of the countries gives cause for concern.

Adolescent↗
PubMed1997

Evaluation of three commercial enzyme-linked immunosorbent assays and two latex agglutination assays for diagnosis of primary Epstein-Barr virus infection.

Three commercially available enzyme-linked immunosorbent assays (ELISAs) from Gull, Biotest, and Behring (Enzygnost) and two latex agglutination tests for heterophile antibodies (Monolatex [Biotest] and Mono-Lex [Trinity Laboratories]) were evaluated for the diagnosis of primary Epstein-Barr virus (EBV) infection and EBV seropositivity. Two hundred fourteen consecutive samples from 197 patients with symptoms of primary EBV infection were analyzed by the five assays at a clinical microbiology laboratory. The samples were also analyzed independently by immunofluorescence methods at a reference laboratory. According to the reference methods, 37 patients (40 serum samples) had primary EBV infections, 120 patients (127 serum samples) had had past EBV infections, 33 patients (36 serum samples) were seronegative, and 7 patients (11 serum samples) exhibited atypical reactions. The respective sensitivities and specificities for the diagnosis of primary EBV infection were 95 and 100% for the Gull assays, 100 and 94% for the Biotest assays, and 100 and 89%, for the Enzygnost assays. The Monolatex and Mono-Lex methods showed similar sensitivities and specificities (78 to 85% and 100 to 99%, respectively) for the diagnosis of primary EBV infection. This study demonstrates the usefulness of commercially available assays for the rapid diagnosis of primary EBV infection, but also the importance of large-scale testing of routine samples before choosing an assay.

Antibodies, Viral↗
PubMed1997

Antimicrobial susceptibility testing in Sweden. II. Species-related zone diameter breakpoints to avoid interpretive errors and guard against unrecognized evolution of resistance.

The Swedish Reference Group for Antibiotics appointed a subcommittee on methodology (SRGA-M) in 1987 to investigate ways of defining interpretive breakpoints for antimicrobial susceptibility testing. The minimum inhibitory concentration (MIC) breakpoints for susceptibility categories are mainly based on pharmacological properties of the antibiotic, and they are, with few exceptions, valid for all species. However, for several species the MIC breakpoints have failed to distinguish strains with reduced susceptibility from normal susceptible strains. Disk diffusion is the routine method for susceptibility testing in Sweden. Studies of distribution of MICs and zone diameters for clinically important bacterial species have resulted in an emphasis on resistance rather than on susceptibility. The SRGA-M chose to place the zone diameter breakpoints close to the native (often susceptible) population of each species or group of related species. Such species-related zone diameter breakpoints used for susceptibility categories no longer correspond to the pharmacological MIC breakpoints, but divide each species into the fully susceptible (native) population and into those isolates/populations that have acquired a resistance mechanism, resulting in high- or low-grade resistance. By this method the risk of reports of false susceptibility is minimized and early detection of the emergence of antibiotic resistance is ensured.

Anti-Bacterial Agents↗
PubMed1997

Antimicrobial susceptibility testing in Sweden. IV. Quality assurance.

The performance of susceptibility testing depends on high-quality material (disks and media), good laboratory practice (robust methodology and correct handling of material) and antimicrobial breakpoints being set in such a way that they allow for some intralaboratory variation. Thus, breakpoints must not divide homogeneous bacterial populations. Routine susceptibility testing should be checked with both internal and external quality control programs. The internal quality control should be designed to demonstrate the importance of minimizing random errors and to rapidly disclose systematic errors. This can be achieved either through the repeated testing of defined control strains or by systematic comparison of histograms of routine zone diameters with reference histograms supplied by the Swedish Reference Group for Antibiotics (SRGA and SRGA-M). The SRGA-M offers an external quality control program which by its design also functions as an epidemiological surveillance program. The quality control programs are supported by an educational program for laboratory personnel.

Anti-Bacterial Agents↗
PubMed1994

Additive effect of clarithromycin combined with 14-hydroxy clarithromycin, erythromycin, amoxycillin, metronidazole or omeprazole against Helicobacter pylori.

The in-vitro activities of clarithromycin, 14-OH clarithromycin, erythromycin, amoxycillin, metronidazole and omeprazole against Helicobacter pylori were determined at pH 7.2 and 5.5. At pH 5.5 the activities of clarithromycin and erythromycin decreased approximately 16 times while 14-OH clarithromycin was less influenced. Chequerboard titration indicated that the combined activity of clarithromycin and the other compounds was additive.

Amoxicillin↗
PubMed1993

The E test for antimicrobial susceptibility testing of Helicobacter pylori.

Antimicrobial susceptibility testing of Helicobacter pylori by conventional means (disc diffusion) is of questionable value because the bacterium grows so slowly. We have determined the susceptibilities of 20 isolates of H. pylori to ampicillin, erythromycin, gentamicin, metronidazole, rifampicin and tetracycline by the E test, a novel technique for measuring MICs, and compared the results with those determined by standard agar dilution and disc diffusion methods. Eighty-one per cent of E test-determined MICs were within one two-fold dilution and 93% were within two two-fold dilutions of those determined by the reference agar dilution method. MICs determined by the E test were highly reproducible; replicate results were invariably within one two-fold dilution. MICs were not affected by the size of the inoculum, preincubation or incubation times. Regression lines for disc diffusion could not be determined because of the lack of resistant strains. However, metronidazole-resistant strains (MIC > 32 mg/L) were easily distinguishable from susceptible strains (MIC < 1 mg/L). In conclusion, the E test is a reliable method for determining the antimicrobial susceptibility of H. pylori.

Anti-Bacterial Agents↗
PubMed1992

Proposed mechanism for metronidazole resistance in Helicobacter pylori.

Metronidazole MIC values were determined for ten isolates of Helicobacter pylori. Under microaerobic conditions four were inhibited by less than 0.25 mg/L, two strains required 2.0 mg/L and four strains had MIC greater than 32 mg/L. The strains were tested for their susceptibility to metronidazole after varying lengths of anaerobic exposure prior to or during microaerobic incubation. The susceptibility was determined by E-test and traditional agar dilution technique. The level of susceptibility of primarily susceptible strains was not significantly affected by a 2 to 24 h period of anaerobic incubation. However, the effect on resistant strains was dramatic. These strains were increasingly susceptible when a 2 to 12 h period of anaerobicity was provided anytime during the first 48 h and fully susceptible (MIC less than 0.1 mg/L) if 24 h of anaerobicity was provided. When tested again under microaerobic conditions the strains exhibited their original MIC values. The composition of the medium did not influence the results. We propose that "metronidazole resistance" in H. pylori is due to a decreased ability of these strains to achieve a sufficiently low redox potential under microaerobic conditions for the necessary reduction of metronidazole, and that these strains during short periods of anaerobicity manage to reduce and "store" sufficient amounts of metronidazole to appear fully susceptible after subsequent microaerobic incubation. microaerobic incubation.

Anaerobiosis↗
PubMed1990

Norfloxacin treatment of salmonellosis does not shorten the carrier stage.

In a prospective controlled study we evaluated the effect of early norfloxacin treatment on the duration of salmonella carriage after acute salmonellosis. The study was carried out during an outbreak of Salmonella typhimurium infection at a military base. 23 patients received norfloxacin 400 mg twice daily for 7 days while 29 patients served as untreated controls. A patient was considered to have ceased being a carrier on the date of the first of 3 negative consecutive cultures. Four weeks after diagnosis 30% of the treated patients and 31% in the control group were still carriers. The corresponding figures after 8 and 12 weeks were 17 and 3% and 4 and 0%, respectively. Thus, one week of norfloxacin treatment instituted at an early stage of salmonellosis did not shorten the duration of carriage.

Adult↗
PubMed1985

Chlorhexidine for prevention of neonatal colonization with group B streptococci. III. Effect of vaginal washing with chlorhexidine before rupture of the membranes.

A single vaginal washing with 2 g/l of chlorhexidine was performed before rupture of the membranes in 19 parturients who were urogenital carriers of group B streptococci (GBS). Two (11%) of the infants became colonized immediately after birth, in contrast to 16 of 41 (39%) infants to controls (P = 0.02). A significant reduction of GBS colonization of the ear (P = 0.02) and umbilicus (P = 0.01) was noted. Taken together, 2 of 57 (4%) cultures obtained at birth were positive in the chlorhexidine group, in contrast to 30 of 123 (24%) among the controls (P less than 0.01). These findings raise hope for the design of a simple washing procedure which might prevent serious infections in the early neonatal period with GBS but also with other chlorhexidine-sensitive organisms.

Adolescent↗
PubMed1985

Vancomycin and netilmicin as first line treatment of peritonitis in CAPD patients.

The first line treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) in our hospital was recently altered from a combination of gentamicin and clindamycin, given as continuous peritoneal lavage, to one of vancomycin and netilmicin given in peritoneal dialysis fluid with prolonged dwell time (4-6 h). The change was prompted by the emergence of multiply resistant Staphylococcus epidermidis among CAPD patients and nursing staff. In 9 of 19 episodes of peritonitis treated with gentamicin/clindamycin, the infecting organism could still be isolated from peritoneal fluid 5-15 days after commencement of therapy. All of 35 culture verified episodes treated with vancomycin/netilmicin were cleared bacteriologically within 3 days (P less than 0.0005). The vancomycin and netilmicin serum levels achieved were 6.5-37.0 mg/l and 1.0-8.1 mg/l, respectively. Apart from an asthmatic reaction, possibly triggered by vancomycin, no side effects were seen. However, audiometry was not performed regularly and the possible effect of netilmicin on the residual renal function was not systematically investigated.

Adult↗
PubMed1985

Scandinavian quality surveys of gentamicin assays 1978-1983.

During 1978-1983 44 Scandinavian laboratories participated in 7 quality surveys of gentamicin serum assays. In each survey 2 test solutions of gentamicin were distributed. In the first 4 surveys very few non-microbiological assays were used while in the 7th survey almost half the laboratories had access to enzyme immunoassay (EMIT). The gentamicin survey mean (SM) concentrations, which did not differ significantly from the intended concentrations, were used as target values. In survey 1, 65% of the results of either of the 2 test solutions were outside the SM +/- 25% and 16% were outside SM +/- 50% ("highly misleading"). In surveys 5 and 7 the corresponding figures were 27 and 5% and 18 and 0%, respectively. The EMIT performed excellently in all surveys. Agar well diffusion assays using Diagnostic Sensitivity Test agar (Oxoid) performed better than other plate diffusion assays. Laboratories participating regularly performed better than others. It is concluded that the survey program, which continues, provides an external facility for unbiased control of commercially available as well as non-commercial assay techniques and that it has been instrumental in the improvement of gentamicin assay standard. It is stressed that the surveys cannot replace internal quality control, best performed by daily measurement and regular statistical evaluation of samples of known potency.

Biological Assay↗
PubMed1984

Aminoglycoside toxicity - a review of clinical studies published between 1975 and 1982.

The present survey of aminoglycoside nephro- and ototoxicity covers approximately 10,000 patients reported on in clinical trials published between 1975 and 1982. Included in the survey were clinical trials with at least 15 patients evaluable for nephro and/or ototoxicity provided relevant data were given on methodology, patient material and aminoglycoside dosage. Each publication was evaluated by both investigators and relevant data entered into a chart. One hundred and forty-four published trials were surveyed; 139, 63 and 34 for renal, cochlear and vestibular side effects, respectively. Frequencies were calculated as number of patients with side effect of total number of evaluated patients. In the average overall figures toxicity labelled by respective authors as 'definitely', 'probably' and 'possibly' related to study drug is included. When available, frequencies of toxicity 'definitely' and 'probably' related to study drug were analysed separately. The average daily dosages of gentamicin, tobramycin, netilmicin and amikacin were 3.9, 3.8, 5.2 and 15.4 mg/kg, respectively. The average frequencies of nephrotoxicity for gentamicin and tobramycin were 14.0 and 12.9%, respectively, and of netilmicin and amikacin 8.7 and 9.4%, respectively. The average frequency of cochlear toxicity was 13.9% for amikacin, 8.3 and 6.1% for gentamicin and tobramycin, respectively, and 2.4% for netilmicin. The material available for evaluation of vestibular toxicity was considerably smaller. The average frequencies for gentamicin, tobramycin and amikacin were similar (3.2 to 3.7%) while netilmicin again exhibited a somewhat lower figure (1.4%). The overall figures and the clinical ranking that they imply were basically substantiated when prospective comparative trials were analysed separately. However, some inconsistencies go unexplained: for example the frequency of gentamicin nephrotoxicity was markedly higher in trials where it was compared to tobramycin (20 trials) than when it was compared to netilmicin (16 trials).

Aminoglycosides↗