Screening tests for pathogenic corynebacteria.
AUTOR(ES)
Colman, G
RESUMO
AIM: To provide simple tests that would help in the identification of corynebacteria that produce diphtheria toxin. METHODS: A collection of 99 freshly isolated corynebacteria was assembled and the cultures identified by conventional tests confirmed by an identification kit. Modifications were made to procedures for preparation of the culture medium for the Elek test and to the test for detection of pyrazinamidase (pyrazine carboxylamidase) activity. These two together with an indicator medium for cystinase activity were applied to the collection of organisms. RESULTS: Cystinase was detected in all 61 members of the toxigenic species and none produced pyrazinamidase. In contrast, all but two of the 38 representatives of non-toxigenic species yielded pyrazinamidase and none formed cystinase. Of the 61 cystinase producing cultures (which were also pyrazinamidase negative), 21 gave a positive Elek test with the modified culture medium. A total of 30 of these 61 were tested for toxigenicity in guinea pigs and the results of the animal and plate tests concorded. At least seven cultures could have been reported as non-toxigenic if Elek tests based on media prepared in the conventional way had been the only test available. CONCLUSION: The three procedures described go some way towards meeting the needs of diagnostic laboratories for efficient procedures for distinguishing pathogenic corynebacteria.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=495813Documentos Relacionados
- Primary structure of the wall peptidoglycan of leprosy-derived corynebacteria.
- Value of acid metabolic products in identification of certain corynebacteria.
- Rapid microbiochemical identification of Corynebacterium diphtheriae and other medically important corynebacteria.
- Activity of ciprofloxacin against multiply resistant strains of Pseudomonas aeruginosa, Staphylococcus epidermidis, and group JK corynebacteria.
- Polymerase chain reaction for screening clinical isolates of corynebacteria for the production of diphtheria toxin.