Mycobacteria causing human cervical lymphadenitis in pastoral communities in the Karamoja region of Uganda

Abstract

SUMMARYMycobacteria from lymph node biopsies of patients with cervical lymphadenitis reporting for tuberculosis treatment in Matany and Moroto Hospitals in the transhumant areas of Karamoja, Uganda were isolated and characterized. The AccuProbe®culture identification kits forMycobacterium tuberculosiscomplex (MTC),M. aviumcomplex (MAC) andM. aviumwere used to identify the isolates. Spoligotyping, IS901PCR and IS1311and IS1245restriction fragment length polymorphism (RFLP) were used to characterize the isolates. Of the 43 biopsies, tenM. avium, sevenM. tuberculosis, threeM. bovis, and twoM. intracellularewere isolated. Two isolates could not be identified with AccuProbe®and from 19 samples no mycobacteria could be isolated. Three isolates with the Beijing spoligotype were identified from the sevenM. tuberculosisisolates. The spoligopatterns of theM. bovisisolates had previously been detected in cattle in Uganda. Isolation of members of the MAC group reflects the complex interaction between the transhumant communities, water sources and their cattle. None of theM. aviumisolates harboured IS901, and all showed several bands on IS1311and IS1245RFLP, in accordance withM. aviumsubsp.hominissuis. Composite dendrograms of IS1311and IS1245RFLP showed that the isolates were similar and identical patterns were found. The isolation ofM. bovisconfirms the human infection with zoonotic mycobacteria in areas where consumption of raw milk and meat is routine. Isolation of environmental mycobacteria also confirms their increasing role in human disease and the occupational risk of infection in the transhumant ecosystem in the absence of safe drinking water and environmental contamination.