COMPUTER-ASSISTED ANALYSIS OF MYCOBACTERIUM-AVIUM FINGERPRINTS USING INSERTION ELEMENTS IS1245 AND IS1311 IN A CARIBBEAN SETTING

A total of 33 clinical isolates of the Mycobacterium avium complex fro m 25 patients, identified by means of biochemical and cultural charact eristics, the Accuprobe system and DT1/DT6 PCR, were further analysed using novel insertion elements IS1245 and IS1311 in a French Caribbean setting. Pvull-cleaved DNA and non-radioactive Southern hybridization and detection systems were used for fingerprinting with both IS eleme nts. The data confirmed the specificity of the two probes for M. avium in our setting and highlighted a significant proportion of M. intrace llulare-infected patients in this region. Two distinct groups composed of 2-3 bands and 6-27 bands were found among M. avium isolates, and w ere composed of the same isolates both with IS1245 and IS 1311. The co mputer analysis of polymorphic banding patterns identified two prevale nt genotypes: one contained 4 isolates from 3 patients while a second 2-banded cluster was composed of 6 isolates from 4 patients; all the p atients were from the same hospital in Guadeloupe. A single isolate fr om Martinique was falsely included in the 2-banded cluster initially u pon IS 1245 fingerprinting, but could be discriminated from other isol ates on the basis of IS 1311 fingerprinting of Pvull-cleaved DNA. Thes e results were also confirmed upon IS 1245 fingerprinting of Pstl-dige sted DNA, as well as DT6 fingerprinting. A single case of polyclonal i nfection was also discovered in a patient at a 75-day interval. This i s the first study comparing the two IS elements and constitutes a firs t description of dissseminated M. avium complex disease from the Carib bean. We conclude that both elements possess a similar discriminatory potential for M. avium isolates. Coupled with computer analysis, this methodology would appear to be particularly suitable for larger epidem iological studies.