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Accurate and user-friendly rapid point-of-care diagnostic tests (POCT) are needed to optimize treatment of Neisseria gonorrhoeae, especially in low-resource settings where syndromic management is the standard of care for sexually transmitted infections. This study aimed to assess the acceptability and usability of a novel lateral flow assay and portable reader for the point-of-care detection of N. gonorrhoeae infection (NG-LFA). This mixed-methods study was conducted as part of a diagnostic performance and usability evaluation of a prototype NG-LFA for detection of N. gonorrhoeae in symptomatic men and women at primary healthcare facilities in the Buffalo City Metro, South Africa. The Standardized System Usability Scale (SUS) was administered, and in-depth interviews were conducted among healthcare professionals (HCPs) and fieldworkers (FWs) at pre-implementation, initial use and 3- and 6-month study implementation to assess user expectations, practical experience, and future implementation considerations for the NG-LFA. Data collection and analysis was guided by the Health Technology Adoption Framework, including new health technology attributes, learnability, satisfaction, and suitability. The framework was adapted to include perceived durability. A total of 21 HCPs and FWs were trained on the NG-LFA use. SUS scores showed good to excellent acceptability ranging from 78.8-90.6 mean scores between HCPs and FWs across study time points. All transcripts were coded using Dedoose and qualitative findings were organized by learnability, satisfaction, suitability, and durability domains. Usability themes are described for each time point. Initial insecurity dissipated and specimen processing dexterity with novel POCT technology was perfected over time especially amongst FWs through practical learning and easy-to-use instructions (learnability). Participants experienced both positive and negative test results, yielding perceived accuracy and minimal testing challenges overall (satisfaction). By 3- and 6-month use, both HCPs and FWs found the NG-LFA convenient to use in primary health care facilities often faced with space constraints and outlined perceived benefits for patients (suitability and durability). Findings show that the NG-LFA device is acceptable and usable even amongst paraprofessionals. High SUS scores and qualitative findings demonstrate high learnability, ease-of-use and suitability that provide valuable information for first-step scale-up requirements at primary healthcare level. Minor prototype adjustments would enhance robustness and durability aspects.

Genes in the genome of 18b that span two genes in H37Rv. (DOCX 24 kb)

Positions of IS6110 in the genome sequences of M. tuberculosis 18b and H37Rv. (DOCX 27 kb)

Hierarchical clustering of differentially expressed genes in SS18b and the results from previous works with 2-fold differences displayed as shrunk and expanded images. (PDF 748 kb)

Genes from H37Rv that are deleted in the genome of 18b. (DOCX 19 kb)

InDels larger than 100 bp between the 18b and the H37Rv genomes. (DOCX 32 kb)

Genes from H37Rv that are deleted in the genome of 18b. (DOCX 19 kb)

Genes from 18b that are deleted in the genome of H37Rv. (DOCX 16 kb)

Weighted Venn diagrams representing overlap of the differential gene expression results from this work with those from stationary phase induction and response to macrophage infection. (PDF 163 kb)

New drugs are needed to control the current tuberculosis (TB) pandemic caused by infection with Mycobacterium tuberculosis. We report here on our work with AX-35, an arylvinylpiperazine amide, and four related analogs, which are potent antitubercular agents in vitro. All five compounds showed good activity against M. tuberculosis in vitro and in infected THP-1 macrophages, while displaying only mild cytotoxicity. Isolation and characterization of M. tuberculosis-resistant mutants to the arylvinylpiperazine amide derivative AX-35 revealed mutations in the qcrB gene encoding a subunit of cytochrome bc1 oxidase, one of two terminal oxidases of the electron transport chain. Cross-resistance studies, allelic exchange, transcriptomic analyses, and bioenergetic flux assays provided conclusive evidence that the cytochrome bc1-aa3 is the target of AX-35, although the compound appears to interact differently with the quinol binding pocket compared to previous QcrB inhibitors. The transcriptomic and bioenergetic profiles of M. tuberculosis treated with AX-35 were similar to those generated by other cytochrome bc1 oxidase inhibitors, including the compensatory role of the alternate terminal oxidase cytochrome bd in respiratory adaptation. In the absence of cytochrome bd oxidase, AX-35 was bactericidal against M. tuberculosis. Finally, AX-35 and its analogs were active in an acute mouse model of TB infection, with two analogs displaying improved activity over the parent compound. Our findings will guide future lead optimization to produce a drug candidate for the treatment of TB and other mycobacterial diseases, including Buruli ulcer and leprosy., mBio, 9 (5), ISSN:2150-7511, ISSN:2161-2129

Genes from 18b that are deleted in the genome of H37Rv. (DOCX 16 kb)

Hierarchical clustering of differentially expressed genes in SS18b and the results from previous works with 2-fold differences displayed as shrunk and expanded images. (PDF 748 kb)

SNPs unique to M. tuberculosis 18b from a comparison with 1793 M. tuberculosis genomes. (DOCX 25 kb)

Hierarchical clustering of differentially expressed genes in SS18b and from previous works showing >2-fold differences. (PDF 332 kb)

Protein coding genes that are annotated as functional in H37Rv and as pseudogenes in 18b. (DOCX 21 kb)

Hierarchical clustering of differentially expressed genes in SS18b and from previous works showing >2-fold differences. (PDF 332 kb)

Positions of IS6110 in the genome sequences of M. tuberculosis 18b and H37Rv. (DOCX 27 kb)

SNPs unique to M. tuberculosis 18b from a comparison with 1793 M. tuberculosis genomes. (DOCX 25 kb)

Genes in the genome of 18b that span two genes in H37Rv. (DOCX 24 kb)

Weighted Venn diagrams representing overlap of the differential gene expression results from this work with those from stationary phase induction and response to macrophage infection. (PDF 163 kb)