Commemorating World TB Day 2020: "IT'S TIME" - It's time to End the Global TB Epidemic

Lite-YOLOv8: a more lightweight algorithm for Tubercle Bacilli detection

Deep learning is a transformative force in the medical field and it has made significant progress as a pivotal alternative to conventional manual testing methods. Detection of Tubercle Bacilli in sputum samples is faced with the problems of complex backgrounds, tiny and numerous objects, and human observation over a long time not only causes eye fatigue, but also greatly increases the error rate of subjective judgement. To solve these problems, we optimize YOLOv8s model and propose a new detection algorithm, Lite-YOLOv8. Firstly, the Lite-C2f module is used to ensure accuracy by significantly reducing the number of parameters. Secondly, a lightweight down-sampling module is introduced to reduce the common feature information loss. Finally, the NWD loss is utilized to mitigate the impact of small object positional bias on the IoU. On the public Tubercle Bacilli datasets, the mean average precision of 86.3% was achieved, with an improvement of 2.2%, 1.5%, and 2.8% over the baseline model (YOLOv8s) in terms of mAP0.5, precision, and recall, respectively. In addition, the parameters reduced from 11.2 to 5.1 M, and the number of GFLOPs from 28.8 to 13.8. Our model is not only more lightweight, but also more accurate, thus it can be easily deployed on computing-poor medical devices to provide greater convenience to doctors.

Design, synthesis and biological evaluation of alkynyl-containing maleimide derivatives for the treatment of drug-resistant tuberculosis

A series of alkynyl-containing maleimides with potent anti-tuberculosis (TB) activity was developed through a rigid group substitution strategy based on our previous study. Systematic optimization of the two side chains flanking the maleimide core led to new compounds with potent activity against Mycobacterium tuberculosis (MIC < 1 μg/mL) and low cytotoxicity (IC₅₀ > 64 μg/mL). Among them, compound 29 not only possessed good activity against extensively drug-resistant TB and favorable hepatocyte stability, but also displayed good intracellular antimycobacterial activity in macrophages. This study lays a good foundation for identifying new alkynyl-containing maleimides as promising leads for treating drug-resistant TB.

Assessment of Knowledge, Attitudes, and Practices (KAP): Public Health and Economic Burden of Tuberculosis in Jarso District of West Wollega Zone, Oromia, Western Ethiopia

Tuberculosis is a communicable mycobacterial disease of humans and animals caused by members of Mycobacterium tuberculosis complex, highly impacting the public health and economy of the country in endemic areas. Retrospective and cross-sectional study was conducted between March and August 2021. For knowledge, attitude, and practices study, five villages were randomly selected using simple random sampling. To quantify the public health burden, one-year data were collected from Jarso Health Center, and unregistered patients were identified using snowball method, and the estimation was based on disability-adjusted life years. Younger age groups (18-40 years) had shown 105.8 times more odds of knowledge towards tuberculosis than the older (>60 years). Moreover, tertiary levels of education had 9395.1 times more odds of knowledge towards tuberculosis compared to illiterates. The estimated economic burden was 7,731.25US$. Of the 51 tuberculosis patients, two died from the disease, resulting in 45.03 disability-adjusted life years. Communities of the study district were heard about tuberculosis, however, unaware of the cause and sources of the infection. Therefore, further strategic and continuous community-based health education and awareness should be given for effective control and prevention of tuberculosis in the study area.

The diagnostic impact of implementing a molecular-based algorithm to standard mycobacterial screening at a reference laboratory with an intermediate prevalence for non-respiratory samples

Rapid, reliable results can be given by molecular, direct detection and identification of the Mycobacterium tuberculosis (MTB/Mtb) complex from clinical samples. The Xpert MTB/RIF assay is an assay that has been availablefor more than a decade for identification of Mycobacterium tuberculosis and resistance to rifampicin. However, there is minimal evidence on its clinical usefulness in paucibacillary, non-respiratory samples. The Xpert MTB/RIF assay clinical utility index, its diagnostic characteristics and the number required to diagnose 2935 non-respiratory specimens submitted for routine mycobacterial work-up in a reference laboratory in an intermediate prevalence setting per specimen form were evaluated. The Xpert MTB/RIF assay showed a variable clinical utility index and number required to diagnose (NND) depending on the type of specimen, which was moderate in tissue biopsies (NND = 1.8) and excellent in pus and urine samples, compared to acid-fast microscopy and culture as a gold standard technique (NND = 1.1 and 1.2). Microscopy, on the other hand, consistently showed a weak to fair index of clinical usefulness in all specimen forms, with in NND of 2.3-12.5. The NND for detecting tuberculous infection in the cerebrospinal fluid by the Xpert MTB/RIF assay was noted to be 1.2, with a moderate clinical utility index of 0.8. The evidence presented indicates that the overall appropriate diagnostic utility of the Xpert MTB/RIF assay is clinically successful in most non-respiratory samples. To check the cost-effectiveness and prognostic effect of integrating this completely automated molecular-based assay into the routine testing algorithm for non-respiratory mycobacterial specimens, further data must be collected.

Induced expression of the zwf gene in the presence of glucose contributes to lowering of glucose 6-phosphate level and consequently reduction of growth rate of Mycobacterium smegmatis

In Mycobacterium smegmatis (renamed Mycolicibacterium smegmatis), glucose 6-phosphate (G6P) level is exceptionally high as compared to other bacteria, E. coli for example. Earlier investigations have indicated that G6P protects M. smegmatis (Msm) against oxidative stress-inducing agents. G6P is a glycolytic intermediate formed either directly through the phosphorylation of glucose or indirectly via the gluconeogenic pathway. Its consumption is catalysed by several enzymes, one of which being the NADPH dependent G6P dehydrogenase (G6PDH) encoded by zwf (msmeg_0314). While investigating the extent to which the carbon sources glucose and glycerol influence Msm growth, we observed that intracellular concentration of G6P was lower in the former's presence than the latter. We could correlate this difference with that in the growth rate, which was higher in glycerol than glucose. We also found that lowering of G6P content in glucose-grown cells was triggered by the induced expression of zwf and the resultant increase in G6PDH activity. When we silenced zwf using CRISPR-Cas9 technology, we observed a significant rise in the growth rate of Msm. Therefore, we have found that depletion of G6P in glucose-grown cells due to increased G6PDH activity is at least one reason why the growth rate of Msm in glucose is less than glycerol. However, we could not establish a similar link-up between slow growth in glucose and lowering of G6P level in the case of Mycobacterium tuberculosis (Mtb). Mycobacteria, therefore, may have evolved diverse mechanisms to ensure that they use glycerol preferentially over glucose for their growth.

Identification of novel benzothiopyranones with ester and amide motifs derived from active metabolite as promising leads against Mycobacterium tuberculosis

We reported three distinct series of novel benzothiopyranones, derived from an active metabolite (M-1) of anti-TB agent 6b. These small molecules were evaluated for their biological activities against a range of Mycobacterium tuberculosis (M. tuberculosis) strains. Preliminary druggability evaluation demonstrated that M-1 showed good aqueous solubility and hepatocyte stability. Benzothiopyranones with acyl, sulfonyl and phosphoryl groups exhibited potent in vitro inhibitory activity against M. tuberculosis H₃₇Rv and low cytotoxicity. In particular, compound 3d, containing a benzoate fragment, displayed marked metabolic stability and potent in vitro activity against drug-resistant tuberculosis clinical strains. Further druggability evaluation based on the identified compounds 3d, 4e and 5b is ongoing for the discovery of promising anti-TB agents.

Development of a Self-Emulsifying Drug Delivery System for Optimized Topical Delivery of Clofazimine

A quality-by-design and characterization approach was followed to ensure development of self-emulsifying drug delivery systems (SEDDSs) destined for topical delivery of the highly lipophilic clofazimine. Solubility and water-titration experiments identified spontaneous emulsification capacity of different excipient combinations and clofazimine. After identifying self-emulsification regions, check-point formulations were selected within the self-emulsification region by considering characteristics required to achieve optimized topical drug delivery. Check-point formulations, able to withstand phase separation after 24 h at an ambient temperature, were subjected to characterization studies. Experiments involved droplet size evaluation; size distribution; zeta-potential; self-emulsification time and efficacy; viscosity and pH measurement; cloud point assessment; and thermodynamic stability studies. SEDDSs with favorable properties, i.e., topical drug delivery, were subjected to dermal diffusion studies. Successful in vitro topical clofazimine delivery was observed. Olive oil facilitated the highest topical delivery of clofazimine probably due to increased oleic acid levels that enhanced stratum corneum lipid disruption, followed by improved dermal clofazimine delivery. Finally, isothermal microcalometric experiments studied the compatibility of excipients. Potential interactions were depicted between argan oil and clofazimine as well as between Span®60 and argan-, macadamia- and olive oil, respectively. However, despite some mundane incompatibilities, successful development of topical SEDDSs achieved enhanced topical clofazimine delivery.