Determinants of health-related quality of life in people with Human Immunodeficiency Virus, failing first-line treatment in Africa.

BACKGROUND: Antiretroviral treatment improves health related quality of life (HRQoL) of people with human immunodeficiency virus (PWH). However, one third initiating first-line treatment experience virological failure and the determinants of HRQoL in this key population are unknown. Our study aims to identify determinants of among PWH failing antiretroviral treatment in sub-Saharan Africa. METHODS: We analysed data from a cohort of PWH having virological failure (> 1,000 copies/mL) on first-line ART in South Africa and Uganda. We measured HRQoL using the EuroQOL EQ-5D-3L and used a two-part regression model to obtain by-country analyses for South Africa and Uganda. The first part identifies risk factors that were associated with the likelihood of participants reporting perfect health (utility = 1) versus non-perfect health (utility < 1). The second part identifies risk factors that were associated with the EQ-5 L-3L utility scores for participants reporting non-perfect health. We performed sensitivity analyses to compare the results between the two-part model using tobit models and ordinary least squares regression. RESULTS: In both countries, males were more likely to report perfect health and participants with at least one comorbidity were less likely to report perfect health. In South Africa, participants with side effects and in Uganda those with opportunistic infections were also less likely to report perfect health. In Uganda, participants with 100% ART adherence were more likely to report perfect health. In South Africa, high HIV viral load, experiencing ART side effects, and the presence of opportunistic infections were each associated with lower HRQoL, whereas participants with 100% ART adherence reported higher HRQoL. In Uganda participants with lower CD4 count had lower HRQoL. CONCLUSION: Markers of advanced disease (opportunistic infection, high viral load, low CD4), side effects, comorbidities and lack of ART adherence negatively impacted HRQoL for PWH experiencing virological failure. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02787499.

Affordable drug resistance genotyping of HIV-1 reverse transcriptase, protease and integrase genes, for resource limited settings.

BACKGROUND: As use of dolutegravir (DTG) becomes more common in resource limited settings (RLS), the demand for integrase resistance testing is increasing. Affordable methods for genotyping all relevant HIV-1 pol genes (i.e., protease (PR), reverse transcriptase (RT) and integrase (IN)) are required to guide choice of future antiretroviral therapy (ART). We designed an in-house HIV-1 drug resistance (HIVDR) genotyping method that is affordable and suitable for use in RLS. METHODS: We obtained remnant plasma samples from CAPRISA 103 study and amplified HIV-1 PR, RT and IN genes, using an innovative PCR assay. We validated the assay using remnant plasma samples from an external quality assessment (EQA) programme. We genotyped samples by Sanger sequencing and assessed HIVDR mutations using the Stanford HIV drug resistance database. We compared drug resistance mutations with previous genotypes and calculated method cost-estimates. RESULTS: From 96 samples processed, we obtained sequence data for 78 (81%), of which 75 (96%) had a least one HIVDR mutation, with no major-IN mutations observed. Only one sample had an E157Q INSTI-accessory mutation. When compared to previous genotypes, 18/78 (23%) had at least one discordant mutation, but only 2/78 (3%) resulted in different phenotypic predictions that could affect choice of subsequent regimen. All CAPRISA 103 study sequences were HIV-1C as confirmed by phylogenetic analysis. Of the 7 EQA samples, 4 were HIV-1C, 2 were HIV-1D, and 1 was HIV-1A. Genotypic resistance data generated using the IDR method were 100% concordant with EQA panel results. Overall genotyping cost per sample was estimated at ~ US$43-$US49, with a processing time of ~ 2 working days. CONCLUSIONS: We successfully designed an in-house HIVDR method that is suitable for genotyping HIV-1 PR, RT and IN genes, at an affordable cost and shorter turnaround time. This HIVDR genotyping method accommodates changes in ART regimens and will help to guide HIV-1 treatment decisions in RLS.

Resistance Testing for Management of HIV Virologic Failure in Sub-Saharan Africa : An Unblinded Randomized Controlled Trial.

BACKGROUND: Virologic failure in HIV predicts the development of drug resistance and mortality. Genotypic resistance testing (GRT), which is the standard of care after virologic failure in high-income settings, is rarely implemented in sub-Saharan Africa. OBJECTIVE: To estimate the effectiveness of GRT for improving virologic suppression rates among people with HIV in sub-Saharan Africa for whom first-line therapy fails. DESIGN: Pragmatic, unblinded, randomized controlled trial. (ClinicalTrials.gov: NCT02787499). SETTING: Ambulatory HIV clinics in the public sector in Uganda and South Africa. PATIENTS: Adults receiving first-line antiretroviral therapy with a recent HIV RNA viral load of 1000 copies/mL or higher. INTERVENTION: Participants were randomly assigned to receive standard of care (SOC), including adherence counseling sessions and repeated viral load testing, or immediate GRT. MEASUREMENTS: The primary outcome of interest was achievement of an HIV RNA viral load below 200 copies/mL 9 months after enrollment. RESULTS: The trial enrolled 840 persons, divided equally between countries. Approximately half (51%) were women. Most (72%) were receiving a regimen of tenofovir, emtricitabine, and efavirenz at enrollment. The rate of virologic suppression did not differ 9 months after enrollment between the GRT group (63% [263 of 417]) and SOC group (61% [256 of 423]; odds ratio [OR], 1.11 [95% CI, 0.83 to 1.49]; P = 0.46). Among participants with persistent failure (HIV RNA viral load ≥1000 copies/mL) at 9 months, the prevalence of drug resistance was higher in the SOC group (76% [78 of 103] vs. 59% [48 of 82]; OR, 2.30 [CI, 1.22 to 4.35]; P = 0.014). Other secondary outcomes, including 9-month survival and retention in care, were similar between groups. LIMITATION: Participants were receiving nonnucleoside reverse transcriptase inhibitor-based therapy at enrollment, limiting the generalizability of the findings. CONCLUSION: The addition of GRT to routine care after first-line virologic failure in Uganda and South Africa did not improve rates of resuppression. PRIMARY FUNDING SOURCE: The President's Emergency Plan for AIDS Relief and the National Institute of Allergy and Infectious Diseases.

In vitro anti-TB properties, in silico target validation, molecular docking and dynamics studies of substituted 1,2,4-oxadiazole analogues against Mycobacterium tuberculosis.

The alarming increase in multi- and extensively drug-resistant (MDR and XDR) strains of Mycobacterium tuberculosis (MTB) has triggered the scientific community to search for novel, effective, and safer therapeutics. To this end, a series of 3,5-disubstituted-1,2,4-oxadiazole derivatives (3a-3i) were tested against H37Rv, MDR and XDR strains of MTB. Of which, compound 3a with para-trifluorophenyl substituted oxadiazole showed excellent activity against the susceptible H37Rv and MDR-MTB strain with a MIC values of 8 and 16 µg/ml, respectively.To understand the mechanism of action of these compounds (3a-3i) and identify their putative drug target, molecular docking and dynamics studies were employed against a panel of 20 mycobacterial enzymes reported to be essential for mycobacterial growth and survival. These computational studies revealed polyketide synthase (Pks13) enzyme as the putative target. Moreover, in silico ADMET predictions showed satisfactory properties for these compounds, collectively, making them, particularly compound 3a, promising leads worthy of further optimisation.

Anti-tubercular activity and molecular docking studies of indolizine derivatives targeting mycobacterial InhA enzyme.

A series of 1,2,3-trisubstituted indolizines (2a-2f, 3a-3d, and 4a-4c) were screened for in vitro whole-cell anti-tubercular activity against the susceptible H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 2b-2d, 3a-3d, and 4a-4c were active against the H37Rv-MTB strain with minimum inhibitory concentration (MIC) ranging from 4 to 32 µg/mL, whereas the indolizines 4a-4c, with ethyl ester group at the 4-position of the benzoyl ring also exhibited anti-MDR-MTB activity (MIC = 16-64 µg/mL). In silico docking study revealed the enoyl-acyl carrier protein reductase (InhA) and anthranilate phosphoribosyltransferase as potential molecular targets for the indolizines. The X-ray diffraction analysis of the compound 4b was also carried out. Further, a safety study (in silico and in vitro) demonstrated no toxicity for these compounds. Thus, the indolizines warrant further development and may represent a novel promising class of InhA inhibitors and multi-targeting agents to combat drug-sensitive and drug-resistant MTB strains.

Geospatial and temporal mapping of detectable HIV-1 viral loads amid dolutegravir rollout in KwaZulu-Natal, South Africa.

South Africa rolled out dolutegravir (DTG) as first-line antiretroviral therapy (ART) in December 2019 to overcome high rates of pretreatment non-nucleoside reverse transcriptase inhibitor drug resistance. In the context of transition to DTG-based ART, this study spatiotemporally analysed detectable HIV viral loads (VLs) prior to- and following DTG rollout in public-sector healthcare facilities in KwaZulu-Natal (KZN) province, the epicentre of the HIV epidemic in South Africa. We retrospectively curated a HIV VL database using de-identified routine VL data obtained from the National Health Laboratory Service for the period January 2018 to June 2022. We analysed trends in HIV viraemia and mapped median log10 HIV VLs per facility on inverse distance weighted interpolation maps. We used Getis-Ord Gi* hotspot analysis to identify geospatial HIV hotspots. We obtained 7,639,978 HIV VL records from 736 healthcare facilities across KZN, of which 1,031,171 (13.5%) had detectable VLs (i.e., VLs ≥400 copies/millilitre (mL)). Of those with detectable VLs, we observed an overall decrease in HIV VLs between 2018 and 2022 (median 4.093 log10 copies/mL; 95% confidence interval (CI) 4.087-4.100 to median 3.563 log10 copies/mL; CI 3.553-3.572), p<0.01 (median test). The downward trend in proportion of HIV VLs ≥1000 copies/mL over time was accompanied by an inverse upward trend in the proportion of HIV VLs between 400 and 999 copies/mL. Moreover, specific coastal and northern districts of KZN had persistently higher VLs, with emergent hotspots demonstrating spatial clustering of high median log10 HIV VLs. The overall decrease in HIV VLs over time shows good progress towards achieving UNAIDS 95-95-95 targets in KZN, South Africa. The DTG-transition has been associated with a reduction in VLs, however, there is a need for pre-emptive monitoring of low-level viraemia. Furthermore, our findings highlight that specific districts will need intensified HIV care despite DTG rollout.

Identification of potent indolizine derivatives against Mycobacterial tuberculosis: In vitro anti-TB properties, in silico target validation, molecular docking and dynamics studies.

In the current study, two sets of compounds: (E)-1-(2-(4-substitutedphenyl)-2-oxoethyl)-4-((hydroxyimino)methyl)pyridinium derivatives (3a-3e); and (E)-3-(substitutedbenzoyl)-7-((hydroxyimino)methyl)-2-substitutedindolizine-1-carboxylate derivatives (5a-5j), were synthesized and biologically evaluated against two strains of Mycobacterial tuberculosis (ATCC 25177) and multi-drug resistant (MDR) strains. Further, they were also tested in vitro against the mycobacterial InhA enzyme. The in vitro results showed excellent inhibitory activities against both MTB strains and compounds 5a-5j were found to be more potent, and their MIC values ranged from 5 to 16 µg/mL and 16-64 µg/mL against the M. tuberculosis (ATCC 25177) and MDR-TB strains, respectively. Compound 5h with phenyl and 4-fluorobenzoyl groups attached to the 2- and 3-position of the indolizine core was found to be the most active against both strains with MIC values of 5 µg/mL and 16 µg/mL, respectively. On the other hand, the two sets of compounds showed weak to moderate inhibition of InhA enzyme activity that ranged from 5 to 17 % and 10-52 %, respectively, with compound 5f containing 4-fluoro benzoyl group attached to the 3-position of the indolizine core being the most active (52 % inhibition of InhA). Unfortunately, there was no clear correlation between the InhA inhibitory activity and MIC values of the tested compounds, indicating the probability that they might have different modes of action other than InhA inhibition. Therefore, a computational investigation was conducted by employing molecular docking to identify their putative drug target(s) and, consequently, understand their mechanism of action. A panel of 20 essential mycobacterial enzymes was investigated, of which ß-ketoacyl acyl carrier protein synthase I (KasA) and pyridoxal-5'-phosphate (PLP)-dependent aminotransferase (BioA) enzymes were revealed as putative targets for compounds 3a-3e and 5a-5j, respectively. Moreover, in silico ADMET predictions showed adequate properties for these compounds, making them promising leads worthy of further optimization.

Oral preexposure prophylaxis uptake, adherence, and persistence during periconception periods among women in South Africa.

OBJECTIVE: We developed the Healthy Families-PrEP intervention to support HIV-prevention during periconception and pregnancy. We evaluated preexposure prophylaxis (PrEP) use with three objective measures. DESIGN: This single-arm intervention study enrolled women in KwaZulu-Natal, South Africa, who were HIV-uninfected, not pregnant, in a relationship with a partner with HIV or unknown-serostatus, and with pregnancy plans. PrEP was offered as part of a comprehensive HIV prevention intervention. Participants were followed for 12 months. METHODS: We evaluated periconception PrEP uptake and adherence using quarterly plasma tenofovir concentrations. We modeled factors associated with PrEP uptake and high plasma tenofovir (past day dosing). Patterns of use were analyzed using electronic pillcap data. Dried blood spots to measure intracellular tenofovir product (past 2 months dosing) were analyzed for a subset of women. RESULTS: Three hundred thirty women with median age 24 (IQR: 22-27) years enrolled. Partner HIV-serostatus was unknown by 96% ( N  = 316); 60% (195) initiated PrEP. High plasma tenofovir concentrations were seen in 35, 25, 22, and 20% of samples at 3, 6, 9, and 12 months, respectively. Similar adherence was measured by pillcap and dried blood spots. In adjusted models, lower income, alcohol use, and higher HIV stigma were associated with high plasma tenofovir. Eleven HIV-seroconversions were observed (incidence rate: 4.04/100 person-years [95% confidence interval: 2.24-7.30]). None had detectable plasma tenofovir. CONCLUSION: The Healthy Families-PrEP intervention supported women in PrEP use. We observed high interest in periconception PrEP and over one-third adhered to PrEP in the first quarter; one-fifth were adherent over a year. High HIV incidence highlights the importance of strategies to reduce HIV incidence among periconception women. CLINICAL TRIAL NUMBER: NCT03194308.

Advancing HIV Drug Resistance Technologies and Strategies: Insights from South Africa's Experience and Future Directions for Resource-Limited Settings.

Monitoring of HIV drug resistance (HIVDR) remains critical for ensuring countries attain and sustain the global goals for ending HIV as a public health threat by 2030. On an individual patient level, drug resistance results assist in ensuring unnecessary treatment switches are avoided and subsequent regimens are tailored on a case-by-case basis, should resistance be detected. Although there is a disparity in access to HIVDR testing in high-income countries compared to low- and middle-income countries (LMICS), more LMICs have now included HIVDR testing for individual patient management in some groups of patients. In this review, we describe different strategies for surveillance as well as where HIVDR testing can be implemented for individual patient management. In addition, we briefly review available technologies for HIVDR testing in LMICs, including Sanger sequencing, next-generation sequencing, and some point-of-care options. Finally, we describe how South Africa has implemented HIVDR testing in the public sector.

Point-of-care urine tenofovir testing to predict HIV drug resistance among individuals with virologic failure.

OBJECTIVE: We sought to evaluate the utility of a point-of-care (POC) urine tenofovir (TFV) assay, developed to objectively assess adherence, to predict HIV drug resistance (HIVDR) in people failing first-line antiretroviral therapy (ART). DESIGN: We retrospectively analyzed TFV levels as a biomarker of adherence in urine specimens collected during a clinical trial that enrolled adults with virologic failure on first-line ART in Uganda and South Africa. METHODS: Urine specimens were analyzed from participants on TFV-containing regimens who had a viral load >1000 copies/ml and paired genotypic resistance test (GRT) results. We assessed recent ART TFV adherence with a qualitative POC lateral flow urine assay with a cut-off value of 1500 ng/ml. We then calculated performance characteristics of the POC urine TFV assay to predict HIVDR, defined as intermediate or high-level resistance to any component of the current ART regimen. RESULTS: Urine specimens with paired plasma GRT results were available from 283 participants. The most common ART regimen during study conduct was emtricitabine, tenofovir disoproxil fumarate, and efavirenz. The overall prevalence of HIVDR was 86% ( n = 243/283). Of those with TFV detected on the POC assay, 91% ( n  = 204/224) had HIVDR, vs. only 66% ( n  = 39/59) among those with no TFV detected ( P- value < 0.001). Positive and negative predictive values of the assay to predict HIVDR were 91% and 34%, respectively. CONCLUSIONS: In populations with a high prevalence of HIVDR, the POC urine TFV assay can provide a low-cost, rapid method to guide requirements for confirmatory resistance testing and inform the need for regimen change.

Seemingly Unrelated Regression Analysis of the Cost and Health-Related Quality of Life Outcomes of the REVAMP Randomized Clinical Trial.

OBJECTIVE: This study aimed to evaluate the 9-month cost and health-related quality of life (HRQOL) outcomes of resistance versus viral load testing strategies to manage virological failure in low-middle income countries. METHODS: We analyzed secondary outcomes from the REVAMP clinical trial: a pragmatic, open label, parallel-arm randomized trial investigating resistance versus viral load testing for individuals failing first-line treatment in South Africa and Uganda. We collected resource data, valued according to local cost data and used the 3-level version of EQ-5D to measure HRQOL at baseline and 9 months. We applied seemingly unrelated regression equations to account for the correlation between cost and HRQOL. We conducted intention-to-treat analyses with multiple imputation using chained equations for missing data and performed sensitivity analyses using complete cases. RESULTS: For South Africa, resistance testing and opportunistic infections were associated with statistically significantly higher total costs, and virological suppression was associated with lower total cost. Higher baseline utility, higher cluster of differentiation 4 (CD4) count, and virological suppression were associated with better HRQOL. For Uganda, resistance testing and switching to second-line treatment were associated with higher total cost, and higher CD4 was associated with lower total cost. Higher baseline utility, higher CD4 count, and virological suppression were associated with better HRQOL. Sensitivity analyses of the complete-case analysis confirmed the overall results. CONCLUSION: Resistance testing showed no cost or HRQOL advantage in South Africa or Uganda over the 9-month REVAMP clinical trial.

Food Insecurity Is Associated With Low Tenofovir Diphosphate in Dried Blood Spots in South African Persons With HIV.

Background: Food insecurity has been linked to suboptimal antiretroviral therapy (ART) adherence in persons with HIV (PWH). This association has not been evaluated using tenofovir diphosphate (TFV-DP) in dried blood spots (DBSs), a biomarker of cumulative ART adherence and exposure. Methods: Within a prospective South African cohort of treatment-naive PWH initiating ART, a subset of participants with measured TFV-DP in DBS values was assessed for food insecurity status. Bivariate and multivariate median-based regression analysis compared the association between food insecurity and TFV-DP concentrations in DBSs adjusting for age, sex, ethnicity, medication possession ratio (MPR), and estimated glomerular filtration rate. Results: Drug concentrations were available for 285 study participants. Overall, 62 (22%) PWH reported worrying about food insecurity and 44 (15%) reported not having enough food to eat in the last month. The crude median concentrations of TFV-DP in DBSs differed significantly between those who expressed food insecurity worry versus those who did not (599 [interquartile range {IQR}, 417-783] fmol/punch vs 716 [IQR, 453-957] fmol/punch; P = .032). In adjusted median-based regression, those with food insecurity worry had concentrations of TFV-DP that were 155 (95% confidence interval, -275 to -35; P = .012) fmol/punch lower than those who did not report food insecurity worry. Age and MPR remained significantly associated with TFV-DP. Conclusions: In this study, food insecurity worry is associated with lower TFV-DP concentrations in South African PWH. This highlights the role of food insecurity as a social determinant of HIV outcomes including ART failure and resistance.

HIV-1 drug resistance in adults and adolescents on protease inhibitor-based antiretroviral therapy in KwaZulu-Natal Province, South Africa.

OBJECTIVES: In low-middle-income countries, increasing levels of HIV drug resistance (HIVDR) on second-line protease inhibitor (PI)-based regimens are a cause for concern given the limited drug options for third-line antiretroviral therapy (ART). We conducted a retrospective analysis of routine HIV-1 genotyping laboratory data from KwaZulu-Natal, South Africa, to describe the frequency and patterns of HIVDR mutations and their consequent impact on standardised third-line regimens. METHODS: This was a cross-sectional analysis of all HIV-1 genotypic resistance tests conducted by the National Health Laboratory Service in KwaZulu-Natal (January 2015 to December 2016) for adults and adolescents (age ≥10 years) on second-line PI-based ART with virological failure. We assigned a third-line regimen to each record based on a national treatment algorithm and calculated the genotypic susceptibility score (GSS) for that regimen. RESULTS: Of 348 samples analysed, 287 (82.5%) had at least one drug resistance mutation (DRM) and 114 (32.8%) had at least one major PI DRM. Major PI resistance was associated with longer duration on second-line ART (aOR per 6-months = 1.11, 95% CI 1.04-1.19) and older age (aOR = 1.03, 95% CI 1.01-1.05). Of 112 patients requiring third-line ART, 12 (10.7%) had a GSS of <2 for the algorithm-assigned third-line regimen. CONCLUSION: One-third of people failing second-line ART had significant PI DRMs. A subgroup of these individuals had extensive HIVDR, where the predicted activity of third-line ART was suboptimal, highlighting the need for continuous evaluation of outcomes on third-line regimens and close monitoring for emergent HIV-1 integrase inhibitor resistance.

Antitubercular, Cytotoxicity, and Computational Target Validation of Dihydroquinazolinone Derivatives.

A series of 2,3-dihydroquinazolin-4(1H)-one derivatives (3a-3m) was screened for in vitro whole-cell antitubercular activity against the tubercular strain H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 3l and 3m with di-substituted aryl moiety (halogens) attached to the 2-position of the scaffold showed a minimum inhibitory concentration (MIC) of 2 µg/mL against the MTB strain H37Rv. Compound 3k with an imidazole ring at the 2-position of the dihydroquinazolin-4(1H)-one also showed significant inhibitory action against both the susceptible strain H37Rv and MDR strains with MIC values of 4 and 16 µg/mL, respectively. The computational results revealed the mycobacterial pyridoxal-5'-phosphate (PLP)-dependent aminotransferase (BioA) enzyme as the potential target for the tested compounds. In vitro, ADMET calculations and cytotoxicity studies against the normal human dermal fibroblast cells indicated the safety and tolerability of the test compounds 3k-3m. Thus, compounds 3k-3m warrant further optimization to develop novel BioA inhibitors for the treatment of drug-sensitive H37Rv and drug-resistant MTB.

Total synthesis of a depsidomycin analogue by convergent solid-phase peptide synthesis and macrolactonization strategy for antitubercular activity.

Depsidomycin is a cyclic heptadepsi-peptide isolated from the cultured broth of Streptomyces lavendofoliae MI951-62F2. It exhibits significant antimicrobial and immunosuppressive activity. The total synthesis of a depsidomycin analogue in which 1,2-piperazine-3-carboxylic acid was substituted with proline is described. After several trials using different strategies, the desired depsidomycin analogue was obtained via stepwise synthesis starting by the amino acid 'head' and macrolactonization under Yamaguchi conditions. The cyclic depsipeptide was evaluated to have an minimum inhibitory concentration (MIC) of 4 µg/ml against H37RV and 16 µg/ml against MDR clinical strains of MTB (MDR-MTB), while the linear precursor 8 also had MICs of 4 and 16 µg/ml for the susceptible and resistant strains, respectively.

HIV-1 Drug Resistance Genotyping in Resource Limited Settings: Current and Future Perspectives in Sequencing Technologies.

Affordable, sensitive, and scalable technologies are needed for monitoring antiretroviral treatment (ART) success with the goal of eradicating HIV-1 infection. This review discusses use of Sanger sequencing and next generation sequencing (NGS) methods for HIV-1 drug resistance (HIVDR) genotyping, focusing on their use in resource limited settings (RLS). Sanger sequencing remains the gold-standard method for detecting HIVDR mutations of clinical relevance but is mainly limited by high sequencing costs and low-throughput. NGS is becoming a more common sequencing method, with the ability to detect low-abundance drug-resistant variants and reduce per sample costs through sample pooling and massive parallel sequencing. However, use of NGS in RLS is mainly limited by infrastructure costs. Given these shortcomings, our review discusses sequencing technologies for HIVDR genotyping, focusing on common in-house and commercial assays, challenges with Sanger sequencing in keeping up with changes in HIV-1 treatment programs, as well as challenges with NGS that limit its implementation in RLS and in clinical diagnostics. We further discuss knowledge gaps and offer recommendations on how to overcome existing barriers for implementing HIVDR genotyping in RLS, to make informed clinical decisions that improve quality of life for people living with HIV.

4-Aryl-1,4-Dihydropyridines as Potential Enoyl-Acyl Carrier Protein Reductase Inhibitors: Antitubercular Activity and Molecular Docking Study.

BACKGROUND: Tuberculosis remains one of the most deadly infectious diseases worldwide due to the emergence of multi-drug resistance (MDR) and extensively drug resistance (XDR) strains of Mycobacterium tuberculosis (MTB). AIMS: Currently, available drugs are getting resistant and toxic. Hence, there is an urgent need for the development of potent molecules to treat tuberculosis. MATERIALS AND METHODS: Herein, the screening of a total of eight symmetrical 1,4-dihydropyridine (1,4- DHP) derivatives (4a-4h) was carried out for whole-cell anti-TB activity against the susceptible H37Rv and MDR strains of MTB. RESULTS AND DISCUSSION: Most of the compounds exhibited moderate to excellent activity against the susceptible H37Rv. Moreover, the most promising compound 4f (against H37Rv) having paratrifluoromethyl phenyl group at 4-position and bis para-methoxy benzyl ester group at 3- and 5- positions of 1,4-dihydropyridine pharmacophore, exhibited no toxicity, but demonstrated weak activity against MTB strains resistant to isoniazid and rifampicin. In light of the inhibitory profile of the title compounds, enoyl-acyl carrier protein reductase (InhA) appeared to be the appropriate molecular target. A docking study of these derivatives against InhA receptor revealed favorable binding interactions. Further, in silico predicted ADME properties of these compounds 4a-4h were found to be in the acceptable ranges, including satisfactory Lipinski's rule of five, thereby indicating their potential as drug-like molecules. CONCLUSION: In particular, the 1,4-DHP derivative 4f can be considered an attractive lead molecule for further exploration and development of more potent anti-TB agents as InhA inhibitors.

Tenofovir diphosphate levels in dried blood spots are associated with virologic failure and resistance to first-line therapy in South Africa: a case-control cohort study.

INTRODUCTION: Tenofovir diphosphate (TFV-DP) in dried blood spots (DBS), a measure of cumulative antiretroviral therapy (ART) adherence, is associated with viral suppression and predicts future viremia in persons with HIV (PWH). However, its utility to identify those at risk for virologic failure (VF) and drug resistance is unknown. To address this, we aimed to establish the association between this adherence biomarker and VF with drug resistance in a cohort of PWH initiating first-line ART in KwaZulu-Natal, South Africa. METHODS: PWH initiating TFV disoproxil fumarate (TDF)-based ART within a parent prospective cohort were evaluated. Using a nested design, DBS for TFV-DP were collected from cases who developed VF (HIV-1 RNA ≥1000 copies/ml) after ≥5 months on ART versus controls, matched 1:2 by site, age, gender, race and ART duration. Cases were categorized as having VF with or without resistance using genotyping. One-way analysis of variance (ANOVA) was used to compare TFV-DP for controls, cases with VF and resistance, and cases with VF without resistance. Data are presented as mean (standard deviation, SD) or geometric mean [95% confidence interval, 95% CI]. RESULTS AND DISCUSSION: One thousand participants were enrolled in the parent study between 2014 and 2016, of which 288 (29%) had DBS available. Of these, 94 (33%) were cases and 194 (67%) were controls; 59% were women. Mean age of our population was 33 (SD 8) years. Genotyping was available in 50 (53%) of the 94 cases. Geometric mean TFV-DP in DBS from controls was 708 [95% CI; 647-773] fmol/punch, which was higher compared to participants having VF with resistance (n = 36), 386 [95% CI; 241-617] fmol/punch and VF without resistance (n = 14), 61 [95% CI; 22-164] fmol/punch; p<0.001. Genotype could not be obtained in 44 (47%) cases. CONCLUSIONS: TFV-DP in DBS showed a stepwise association with VF and drug resistance in South African PWH. Participants having VF with resistance had mid-range concentrations of TFV-DP, which were higher than those for PWH without resistance. Future research on the clinical utility of TFV-DP concentrations in DBS to predict and prevent the development of VF and drug resistance is needed.

Anti-Tubercular Properties of 4-Amino-5-(4-Fluoro-3- Phenoxyphenyl)-4H-1,2,4-Triazole-3-Thiol and Its Schiff Bases: Computational Input and Molecular Dynamics.

In the present investigation, the parent compound 4-amino-5-(4-fluoro-3-phenoxyphenyl)-4H-1,2,4-triazole-3-thiol (1) and its Schiff bases 2, 3, and 4 were subjected to whole-cell anti-TB against H37Rv and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) by resazurin microtiter assay (REMA) plate method. Test compound 1 exhibited promising anti-TB activity against H37Rv and MDR strains of MTB at 5.5 µg/mL and 11 µg/mL, respectively. An attempt to identify the suitable molecular target for compound 1 was performed using a set of triazole thiol cellular targets, including ß-ketoacyl carrier protein synthase III (FABH), ß-ketoacyl ACP synthase I (KasA), CYP121, dihydrofolate reductase, enoyl-acyl carrier protein reductase, and N-acetylglucosamine-1-phosphate uridyltransferase. MTB ß-ketoacyl ACP synthase I (KasA) was identified as the cellular target for the promising anti-TB parent compound 1 via docking and molecular dynamics simulation. MM(GB/PB)SA binding free energy calculation revealed stronger binding of compound 1 compared with KasA standard inhibitor thiolactomycin (TLM). The inhibitory mechanism of test compound 1 involves the formation of hydrogen bonding with the catalytic histidine residues, and it also impedes access of fatty-acid substrates to the active site through interference with α5-α6 helix movement. Test compound 1-specific structural changes at the ALA274-ALA281 loop might be the contributing factor underlying the stronger anti-TB effect of compound 1 when compared with TLM, as it tends to adopt a closed conformation for the access of malonyl substrate to its binding site.

Laboratory diagnosis of tuberculous meningitis in human immunodeficiency virus-seropositive patients: Correlation with the uniform case definition.

BACKGROUND: Laboratory confirmation of the diagnosis of tuberculous meningitis (TBM) has always been problematic. Using the uniform case definition suggested by Marais et al., we determined the sensitivity of a variety of laboratory tests. METHODS: Human immunodeficiency virus (HIV)-seropositive patients suspected of having subacute meningitis were included in the study. Using the uniform case definition, patients were divided into possible and probable cases of TBM. The following specific tests were done on the cerebrospinal fluid (CSF): layered Ziehl-Neelsen (ZN) staining, CSF culture and a panel of nucleic acid amplification tests (NAAT) consisting of the GenoType MTBDRplus assay, Cepheid Xpert MTB/RIF, the MTB Q-PCR Alert (Q-PCR) and the loop-mediated isothermal amplification (LAMP) assay. The sensitivity of each test was compared to the case definition and to each other. RESULTS: A total of 68 patients were evaluated. Using the uniform case definition only, without any of the specific laboratory tests, there were 15 probable cases (scores > 12) and 53 possible cases (scores 6-11) of TBM. When the uniform case definition was tested against any laboratory test, 12 of the 15 (80%) probable cases and 26 of the 53 (49.1%) possible cases had laboratory confirmation. When each test was compared to any other test, the sensitivities for the Xpert MTB/RIF, GenoType MTBDRplus, CSF culture, Q-PCR, LAMP and ZN layering were 63.2 (46.0-78.2), 76.3 (59.8-88.6), 65.7 (47.8-80.9), 81.1 (64.8-92.0), 70.3 (53.0-84.1) and 55.6 (38.1-72.1), respectively. CONCLUSION: In this study, the GenoType MTBDRplus and the Q-PCR tests performed better than the Xpert MTB/RIF. Because the Xpert MTB/RIF is not good enough to 'rule out' TBM, a negative result should be followed up by another NAAT, such as the GenoType MTBDRplus or Q-PCR. The LAMP assay may be considered as the first test in resource-poor settings. At the time of the study, we did not have access to the Xpert MTB/RIF Ultra, which has now been recommended by the World Health Organization as the test of first choice. However, even this test has a similar limitation as the Xpert MTB/RIF, with two recent studies showing variable results.