Diagnosis of tuberculosis in pediatric patients remains challenging due to inherent difficulties associated with obtaining respiratory samples for molecular and culture-based testing. To address this, recent studies have highlighted the utility of tongue swabs to detect Mycobacterium tuberculosis genomic DNA in the oral epithelia of tuberculosis infected adults. It is unknown whether tongue swabs have similar utility for diagnosis of childhood tuberculosis and if the presence of DNA in these swabs was associated with whole bacilli. We therefore sought to conduct a preliminary assessment of the utility of tongue swabs to detect tubercle bacilli and their associated genetic material in young children. For this, we recruited hospitalized children with clinically diagnosed tuberculosis (n = 26) or lower respiratory tract infection (LRTI, n = 9). These categories were blinded for downstream laboratory tests, which included PCR, spoligotyping, smear microscopy, and culture. Mtb genomic DNA was detected by PCR only in clinically diagnosed TB cases [11/26 (31.4%)] and not in cases with LRTI. Of these, 5/11 [45.5%] were associated with a spoligotype. Spoligotyping also detected an additional six specimens that were negative by PCR. Using smear microscopy, 19/26 [73.1%] and 4/9 [44.4] were Mtb positive in the tuberculosis or LRTI categories respectively. We noted positive results on all three tests in 5/26 [19.2%] in the tuberculosis category and 0/9 in the LRTI category. All specimens were culture negative. Collectively, these preliminary data present a compelling case for broader testing of tongue swabs to diagnose tuberculosis in children where obtaining standard sputum specimens is not easy.

Lopsy is a siphovirus mycobacteriophage that is capable of lytic infection in Mycobacterium smegmatis . It is classified as a subcluster B1 mycobacteriophage and was isolated from soil in Estcourt, South Africa. The 68,542-bp double-stranded DNA genome is circularly permuted, has a GC content of 66.4%, and is predicted to contain 98 genes.

IgnatiusPatJac is a Siphoviridae mycobacteriophage capable of lytic infection in Mycobacterium smegmatis and Mycobacterium tuberculosis . It was isolated from damp soil in Johannesburg, South Africa. The 51,164-bp double-stranded DNA genome has a GC content of 63.6%, predicted to encode 93 genes. IgnatiusPatJac is classified as an A1 subcluster mycobacteriophage.