Fine-needle aspiration may replace skin biopsy for the collection of material for experimental infection of mice with Mycobacterium leprae and Lacazia loboi.

BACKGROUND: Procedures involving the use of Mycobacterium leprae and Lacazia loboi, uncultivated organisms, depend on the collection of material from the lesions of patients or experimental animals. This study compared fine-needle aspiration (FNA) and skin biopsy methods for obtaining bacilli and fungal cells to experimentally infect animals. METHODS: Lepromas from one armadillo and one enlarged footpad of a mouse previously inoculated with L. loboi were submitted to FNA and biopsy. Materials collected were processed for inoculation in mice. RESULTS: Acid-fast bacilli (AFB) collected by two FNA procedures yielded 7.2x10(7) and 5.3x10(6) AFB/ml and biopsies yielded 1.58x10(8) and 3.5x10(8) AFB/ml from each leproma. Yeast-like cells of L. loboi collected by FNA yielded 1.0x10(6) fungal cells/ml and biopsy 1.0x10(7) fungal cells/ml. After 8 months, inoculated animals were sacrificed and the inoculated footpads submitted to histopathological examination and counting of AFB and fungal cells. The results obtained by the two methods were comparable for both microorganisms. CONCLUSIONS: Biopsy may be replaced by FNA during harvesting of material for different purposes, especially for experimental inoculation of mice in leprosy and Jorge Lobo's disease, with the advantage of FNA being a simpler, less invasive, and less costly method.