Evaluation of the Mycobacterium bovis restriction fragment length polymorphism probe pUCD, in combination with the direct repeat probe, for moleculartyping of Mycobacterium tuberculosis strains in Ireland

A mycobacterial restriction fragment length polymorphism probe, pUCD, has r ecently been described which represents an effective tool for the strain ty ping of Mycobacterium bovis. The present study evaluated this probe, in com bination with the direct repeat probe (DR), for the molecular typing of 90 strains of Mycobacterium tuberculosis from 87 patients, looking at a group (62 isolates) of nonselected samples to assess pUCD combined with DR as a g eneral tool and a subset of 32 isolates with a common specific IS6110 strai n type in Ireland. Within the group of 62 isolates, pUCD-DR identified 42 s trains and was comparable to both IS6110 (41 strains) and polymorphic guani ne-cytosine-rich sequence (PGRS) (37 strains) analysis. pUCD-DR was found t o be comparable to IS6110 and PGRS in identifying four separate clusters of isolates which were confirmed to be clinically related. pUCD-DR divided th e common IS6110 isolates into six distinct types and was comparable to PGRS (seven strain types). The usefulness of this probe as an epidemiological t ool is discussed.