RESUMEN
The adenylate cyclase activity of Bordetella pertussis in clinical isolates was measured in calmodulin-supplemented Stainer-Scholte broth by the rate of conversion of ATP to cyclic AMP. Analysis of 250 stock strains of Bordetella pertussis showed that measurable adenylate cyclase activity was produced by all strains. In clinical tests Bordetella pertussis was isolated from 135 (22%) of 605 swab samples. Increased adenylate cyclase activity was detected in 124 (92%) Stainer-Scholte broth cultures of these samples. A total of 475 swabs contained other bacteria or had no growth; only one of the Stainer-Scholte broth cultures of these swab samples contained measurable adenylate cyclase activity. The results indicate that testing for adenylate cyclase activity provides a specific and sensitive means for detecting Bordetella pertussis in clinical specimens.
Asunto(s)
Adenilil Ciclasas/metabolismo , Bordetella pertussis/enzimología , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Adulto , Bacterias/enzimología , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas , Bordetella pertussis/aislamiento & purificación , Niño , Humanos , Mucosa Nasal/microbiología , Especificidad de la Especie , Especificidad por SustratoRESUMEN
A semiselective medium for the detection of multiresistant lipophilic corynebacteria is described. The medium consisted of tryptose agar, supplemented with Tween 80, lecithin, histidine, glycerol, sodium thiosulfate, fosfomycin, ticarcillin, and 5-fluorocytosine. The medium was tentatively called lecithin-Tween medium (LT medium). It promoted mainly the growth of Corynebacterium group JK, which has recently been identified as a cause of serious infection in immunocompromised patients. The application of LT medium to 6,859 routine clinical specimens increased the percentage of Corynebacterium group JK isolation from 0.1 to 1.0%. Although a total of 72 isolates were found in 65 patients, on the basis of clinical criteria only 2 patients were regarded as having an infection with these bacteria. Consequently, Corynebacterium group JK infection can only be diagnosed through a combination of clinical and microbiological findings. In high-risk areas, however, the use of LT medium for surveillance may facilitate the early detection of these potentially dangerous organisms.