Detection of extended-spectrum beta-lactamases. The reliability of methods for susceptibility testing as used in Denmark.

The susceptibility testing methods used in Denmark were evaluated with respect to their ability to detect cephalosporin resistance with cefuroxime as indicator, especially resistance caused by extended-spectrum beta-lactamases (ESBLs). Two methods for determination of minimal inhibitory concentration (MIC), three agar diffusion methods, a disc approximation test and the ESBL-Etest were used against a panel of strains producing well-known beta-lactamases. The tablet diffusion test (Rosco Neo Sensitabs) as the most used in Denmark had the lowest detection rate of cefuroxime resistance among ESBL-producing strains. The prediffusion method, which is only used at one laboratory, was the most reliable method for such detection. The MIC methods were in good agreement, but the detection rate for resistance due to ESBLs was low and depended on the antibiotics used. The disc approximation test and the ESBL-Etest both resulted in an acceptable ESBL detection rate. The latter tests discriminated between isolates producing the frequent chromosome-mediated and the in Denmark probably very rare ESBL-mediated cephalosporin resistance. For the evaluation of susceptibility tests such strains require special attention.

[Bacteremia in the county of Ribe]. / Bakteriaemi i Ribe Amt.

The Department of Microbiology at the Central Hospital of Esbjerg, established in 1987, serves the five hospitals in Ribe county, Denmark. From early on, the department has endeavoured to guide the hospital's antimicrobial policy. In order to investigate whether this involvement had any measurable impact on the antimicrobial resistance pattern in our region, we compared the resistance patterns of 212 strains isolated from the blood of bacteraemic patients in 1988 to those of 317 strains isolated in 1992. No increase in antibiotic resistance was revealed. This is noteworthy since new specialties have been established at the Central Hospital during this period, with an increased number of patients requiring antimicrobial therapy. It is important to survey the antibiotic resistance pattern closely, and that this is done locally.

[Septicemia caused by Malassezia furfur]. / Septikaemi forårsaget af Malassezia furfur.

A case of septicaemia caused by Malassezia furfur in a newborn patient receiving intravenous nutrition is presented. M. furfur, the well known cause of pityriasis versicolor, is a strict lipophilic yeast, with predilection for indwelling catheters conducting lipid solutions. Since the diagnosis of M. furfur is hampered by the slow growth and the requirement of lipid containing growth media, one must keep the organism in mind when signs of septicaemia occur in a patient receiving parenteral nutrition, especially in premature infants.

Adrenocortical function in children on high-dose steroid aerosol therapy. Results of serum cortisol, ACTH stimulation test and 24 hour urinary free cortical excretion.

The adrenocortical function was investigated in 18 children treated with high-doses of inhaled glucocorticoid aerosol (mean: 1965 micrograms/1.73 m2 body surface a day). Basal serum cortisol was only below the normal range in patients treated with doses exceeding 2500 micrograms/1.73 m2 body surface. 15 of 18 children had normal 24 h urinary free cortisol excretion, compared with 27 normal children matched for age, sex and body surface. Three patients taking more than 2400 micrograms/1.73 m2 body surface showed excretion values below the range for the normal controls. 10 of 12 patients showed a normal response to a short ACTH stimulation test. One patient treated with 3300 micrograms/1.73 m2 body surface showed no response and one patient gave a borderline response to ACTH. We concluded that doses up to 2000 micrograms/1.73 m2 body surface/24 can be administered by pressurized aerosol with little risk of adrenocortical suppression.