Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae

BACKGROUND The detection of live Mycobacterium leprae in soil and animals other than humans suggests that the environment plays a role in the transmission of leprosy. OBJECTIVE The objective of this study was to investigate the presence of viable M. leprae in natural water sources used by the local population in five municipalities in the state of Ceará, northeastern Brazil. METHODS Samples were collected from 30 different sources. Viable bacilli were identified by reverse transcriptase polymerase chain reaction (PCR) of the M. leprae gyrA gene and sequencing of the PCR products. Physicochemical properties of each water source were also assessed. FINDINGS M. leprae gyrA mRNA was found in 23 (76.7%) of the water sources. No association was found between depth of the water and sample positivity, nor was there any association between the type of water used by the population and sample positivity. An association between viable M. leprae and temperature and pH was found. Georeferencing showed a relation between the residences of leprosy cases and water source containing the bacterium. MAIN CONCLUSIONS The finding of viable M. leprae in natural water sources associated with human contact suggests that the environment plays an important role in maintaining endemic leprosy in the study region.

Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3%) isolates were resistant to at least one drug (R-TB) and 64 (55.7%) were sensitive to all the drugs tested (S-TB). A high frequency of resistance was found in previously treated cases (84%) and among new cases (16%; p < 0.001). a total of 74 (64%) isolates were grouped into 22 spoligotyped lineages, while 41 (36%) isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam), 12% haarlem (h), and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23%) patients (hot spot zones) either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.