Background: Triatomine insects, native to northeastern Brazil, have been found in the urban peridomicile. The city of Sobral has a high number of tuberculosis cases and several triatomine species. This study investigates the presence of mycobacteria, particularly Mycobacterium tuberculosis complex (MTBC) species, in triatomines captured in the urban perimeter of Sobral.
Methods: We analyzed 167 triatomines captured in urban households and peridomiciles of Sobral. Mycobacteria were identified by the PRA-hsp65 method followed by partial sequencing of the hsp65 and rpoB genes. The sequences confirmed as MTBC were also typed by mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) and spoligotyping.
Results: Triatoma brasiliensis (38.6%), Triatoma pseudomaculata (32.9%), Panstrongylus lutzi (24.3%) were the most frequently identified. In 51.1% (70/167) of them, species of the Mycobacteriaceae family were detected by PRA-hsp65; of these, 31.4% (22/70) were identified as belonging to MTBC species. Nine (12.9%) of the triatomine samples were confirmed by sequencing as belonging to MTBC species. MIRU-VNTR genotyping suggests that the presence of different MTBC sublines in the triatomines should be investigated.
Conclusion: This is the first report of MTBC lineages in triatomine insects. These results indicate the migration and adaptation of these insects in an urban setting.
Keywords: Hemiptera; Mycobacterium tuberculosis; Triatominae; mycobacteria; sequencing analysis; tuberculosis.