DIRECT-DETECTION AND IDENTIFICATION OF MYCOBACTERIUM ULCERANS IN CLINICAL SPECIMENS BY PCR AND OLIGONUCLEOTIDE-SPECIFIC CAPTURE PLATE HYBRIDIZATION

We compared various diagnostic tests for their abilities to detect Myc obacterium ulcerans infection in specimens from patients with clinical ly active disease. Specimens from 10 patients from the area of Zangnan ado (Department of Zou, Benin) with advanced, ulcerated active M. ulce rans infections were studied by direct smear, histopathology, culture, PCR, and oligonucleotide-specific capture plate hybridization (OSCPH) . A total of 27 specimens, including 12 swabs of exudate collected bef ore debridement and 15 fragments of tissue obtained during debridement , were submitted to bacteriologic and histopathologic analysis. The hi stopathologic evaluation of tissues from all six patients so tested re vealed changes typical of those caused by M. ulcerans infection. Five specimens were contaminated, and M. ulcerans was cultivated on Lowenst ein-Jensen medium from 12 of the remaining 22 (54.5%) specimens. Detec tion of mycobacteria was performed by PCR, and M. ulcerans was detecte d by OSCPH with a new probe (5'-CACGGGATTCATGTCCTGT-3') reacting with M. ulcerans and Mycobacterium marinum. In 10 of 22 (45.5%) specimens, M. ulcerans was identified by PCR-OSCPH. There was no statistically si gnificant difference between the detection of M. ulcerans by culture a nd by PCR-OSCPH (P > 0.05). This is the first demonstration of an ampl ification system (PCR-OSCPH) with a sensitivity similar to that of cul ture for the direct and rapid recognition of M. ulcerans in clinical s pecimens. This system is capable of identifying M. ulcerans, even in p aucibacillary lesions. Our findings suggest that PCR-OSCPH should be u sed in the quest for the elusive environmental reservoir(s) of M. ulce rans.