Scaling up interventions to achieve global tuberculosis control: progress and new developments

Exploring the potential of Lactocaseibacillus rhamnosus PMC203 in inducing autophagy to reduce the burden of Mycobacterium tuberculosis

Mycobacterium tuberculosis, a lethal pathogen in human history, causes millions of deaths annually, which demands the development of new concepts of drugs. Considering this fact, earlier research has explored the anti-tuberculosis potential of a probiotic strain, Lactocaseibacillus rhamnosus PMC203, leading to a subsequent focus on the molecular mechanism involved in its effect, particularly on autophagy. In this current study, immunoblotting-based assay exhibited a remarkable expression of autophagy marker LC3-II in the PMC203 treated group compared to an untreated group. A remarkable degradation of p62 was also noticed within treated cells compared to control. Furthermore, the immunofluorescence-based assay showed significant fold change in fluorescence intensity for alexa-647-LC3 and alexa-488-LC3, whereas p62 was degraded noticeably. Moreover, lysosomal biogenesis generation was elevated significantly in terms of LAMP1 and acidic vesicular organelles. As a result, PMC203-induced autophagy played a vital role in reducing M. tuberculosis burden within the macrophages in treated groups compared to untreated group. A colony -forming unit assay also revealed a significant reduction in M. tuberculosis in the treated cells over time. Additionally, the candidate strain significantly upregulated the expression of autophagy induction and lysosomal biogenesis genes. Together, these results could enrich our current knowledge of probiotics-mediated autophagy in tuberculosis and suggest its implications for innovatively managing tuberculosis.

Multidrug-resistant tuberculosis

One of predominant contributors to global mortality is tuberculosis (TB), an infection caused by Mycobacterium tuberculosis (MTB). Inappropriate and ineffectual treatment can lead to the development of drug-resistant TB. One of the most common forms of drug-resistant TB is multidrug-resistant tuberculosis (MDR-TB), caused by mutations in the rpoB and katG genes that lead to resistance to anti-TB drugs, rifampicin (RIF) and isoniazid (INH), respectively. Although culturing remains the gold standard, it is not rapid thereby delaying potential treatment and potentially increasing the incidence of MDR-TB. In contrast, molecular techniques provide a highly sensitive and specific alternative. This review discusses the classification of biomarkers used to detect MDR-TB, some of the commonly used anti-TB drugs, and DNA mutations in MTB that lead to anti-TB resistance. The objective of this review is to increase awareness of the need for rapid and precise detection of MDR-TB cases to decrease morbidity and mortality of this infectious disease worldwide.

Classification of early tuberculosis states to guide research for improved care and prevention: an international Delphi consensus exercise

The current active-latent paradigm of tuberculosis largely neglects the documented spectrum of disease. Inconsistency with regard to definitions, terminology, and diagnostic criteria for different tuberculosis states has limited the progress in research and product development that are needed to achieve tuberculosis elimination. We aimed to develop a new framework of classification for tuberculosis that accommodates key disease states but is sufficiently simple to support pragmatic research and implementation. Through an international Delphi exercise that involved 71 participants representing a wide range of disciplines, sectors, income settings, and geographies, consensus was reached on a set of conceptual states, related terminology, and research gaps. The International Consensus for Early TB (ICE-TB) framework distinguishes disease from infection by the presence of macroscopic pathology and defines two subclinical and two clinical tuberculosis states on the basis of reported symptoms or signs of tuberculosis, further differentiated by likely infectiousness. The presence of viable Mycobacterium tuberculosis and an associated host response are prerequisites for all states of infection and disease. Our framework provides a clear direction for tuberculosis research, which will, in time, improve tuberculosis clinical care and elimination policies.

Finding and treating both tuberculosis disease and latent infection during population-wide active case finding for tuberculosis elimination

In recognition of the high rates of undetected tuberculosis in the community, the World Health Organization (WHO) encourages targeted active case finding (ACF) among "high-risk" populations. While this strategy has led to increased case detection in these populations, the epidemic impact of these interventions has not been demonstrated. Historical data suggest that population-wide (untargeted) ACF can interrupt transmission in high-incidence settings, but implementation remains lacking, despite recent advances in screening tools. The reservoir of latent infection-affecting up to a quarter of the global population -complicates elimination efforts by acting as a pool from which future tuberculosis cases may emerge, even after all active cases have been treated. A holistic case finding strategy that addresses both active disease and latent infection is likely to be the optimal approach for rapidly achieving sustainable progress toward TB elimination in a durable way, but safety and cost effectiveness have not been demonstrated. Sensitive, symptom-agnostic community screening, combined with effective tuberculosis treatment and prevention, should eliminate all infectious cases in the community, whilst identifying and treating people with latent infection will also eliminate tomorrow's tuberculosis cases. If real strides toward global tuberculosis elimination are to be made, bold strategies are required using the best available tools and a long horizon for cost-benefit assessment.

Cell state transition analysis identifies interventions that improve control of Mycobacterium tuberculosis infection by susceptible macrophages

Understanding cell state transitions and purposefully controlling them to improve therapies is a longstanding challenge in biological research and medicine. Here, we identify a transcriptional signature that distinguishes activated macrophages from the tuberculosis (TB) susceptible and resistant mice. We then apply the cSTAR (cell state transition assessment and regulation) approach to data from screening-by-RNA sequencing to identify chemical perturbations that shift the transcriptional state of tumor necrosis factor (TNF)-activated TB-susceptible macrophages toward that of TB-resistant cells, i.e., prevents their aberrant activation without suppressing beneficial TNF responses. Last, we demonstrate that the compounds identified with this approach enhance the resistance of the TB-susceptible mouse macrophages to virulent Mycobacterium tuberculosis.

A Review of Approaches to the Metallic and Non-Metallic Synthesis of Benzimidazole (BnZ) and Their Derivatives for Biological Efficacy

Heterocyclic compounds are significant lead drug candidates based on their various structure-activity relationships (SAR), and their use in pharmaceutics is constantly developing. Benzimidazole (BnZ) is synthesized by a condensation reaction between benzene and imidazole. The BnZ structure consists of two nitrogen atoms embedded in a five-membered imide ring which is fused with a benzene ring. This review examines the conventional and green synthesis of metallic and non-metallic BnZ and their derivatives, which have several potential SARs, along with a wide range of pharmacological properties, including anti-cancer, anti-inflammatory, anti-microbial, anti-tubercular, and anti-protozoal properties. These compounds have been proven by pharmacological investigations to be efficient against different strains of microbes. Therefore, in this review, the structural variations of BnZ are listed along with various applications, predominantly related to their biological activities.

Estimating the prevalence of poor-quality anti-TB medicines: a neglected risk for global TB control and resistance

OBJECTIVES

Tuberculosis (TB) remains a major global public health problem, especially with the recent emergence of multidrug-resistant TB and extensively drug-resistant TB. There has been little consideration of the extent of substandard and falsified (SF) TB medicines as drivers of resistance. We assessed the evidence on the prevalence of SF anti-TB medicines and discussed their public health impact.

MATERIALS/METHODS

We searched Web of Science, Medline, Pubmed, Google Scholar, WHO, US Pharmacopeia and Medicines Regulatory Agencies websites for publications on anti-TB medicines quality up to 31 October 2021. Publications reporting on the prevalence of SF anti-TB drugs were evaluated for quantitative analysis.

RESULTS

Of the 530 screened publications, 162 (30.6%) were relevant to anti-TB medicines quality; of those, 65 (40.1%) described one or more TB quality surveys in a specific location or region with enough information to yield an estimate of the local prevalence of poor-quality TB medicines. 7682 samples were collected in 22 countries and of those, 1170 (15.2%) failed at least one quality test. 14.1% (879/6255) of samples failed in quality surveys, 12.5% (136/1086) in bioequivalence studies and 36.9% (87/236) in accelerated biostability studies. The most frequently assessed were rifampicin monotherapy (45 studies, 19.5%) and isoniazid monotherapy (33, 14.3%), rifampicin-isoniazid-pyrazinamide-ethambutol fixed dose combinations (28, 12.1%) and rifampicin-isoniazid (20, 8.6%). The median (IQR) number of samples collected per study was 12 (1-478).

CONCLUSIONS

SF, especially substandard, anti-TB medicines are present worldwide. However, TB medicine quality data are few and are therefore not generalisable that 15.2% of global anti-TB medicine supply is SF. The evidence available suggests that the surveillance of the quality of TB medicines needs to be an integral part of treatment programmes. More research is needed on the development and evaluation of rapid, affordable and accurate portable devices to empower pharmacy inspectors to screen for anti-TB medicines.

Comparison of Ziehl Neelsen microscopy and geneXpert for the diagnosis of pulmonary tuberculosis among pulmonary tuberculosis-suspected patients in northwest Ethiopia

In low-income countries, the diagnosis of pulmonary tuberculosis (PTB) is most frequently achieved using Ziehl Neelsen (ZN) microscopy rather than the GeneXpert system. The performance of the former has not been evaluated against the latter in Ethiopia. A total of 180 PTB-suspected patients were enrolled in our study. Sputum specimens were tested both by ZN microscopy and geneXpert. The sensitivity, specificity, positive predictive value, and negative predictive value of ZN microscopy were 75%, 99.4%, 92.3%, and 97.6%, respectively. The Kappa value of agreement between the two diagnosis methods was 0.80. We concluded that there was a good agreement between ZN microscopy and the reference Xpert assay, which suggests that ZN microscopy is still a good diagnostic method in health care facilities that do not have the latter test.

Cell state transition analysis identifies interventions that improve control of M. tuberculosis infection by susceptible macrophages

Understanding cell state transitions and purposefully controlling them to improve therapies is a longstanding challenge in biological research and medicine. Here, we identify a transcriptional signature that distinguishes activated macrophages from TB-susceptible and TB-resistant mice. We then apply the cSTAR (cell State Transition Assessment and Regulation) approach to data from screening-by-RNA sequencing to identify chemical perturbations that shift the. transcriptional state of the TB-susceptible macrophages towards that of TB-resistant cells. Finally, we demonstrate that the compounds identified with this approach enhance resistance of the TB-susceptible mouse macrophages to virulent M. tuberculosis .

Bronchial Washing Using a Thin Versus a Thick Bronchoscope to Diagnose Pulmonary Tuberculosis: A Randomized Trial

BACKGROUND

This study was performed to evaluate the efficacy of using a thin bronchoscope for the diagnosis of pulmonary tuberculosis (PTB).

METHODS

Between March 2019 and November 2021, we prospectively enrolled participants with suspected PTB whose sputum acid-fast bacilli (AFB) smear and tuberculosis (TB) polymerase chain reaction (PCR) tests were negative or who could not produce self-expectorated sputum. Participants were randomized to a control group (bronchial washing [BW] using a 5.9-mm conventional bronchoscope guided by chest computed tomography) or an investigational group (BW using a 4.0-mm thin bronchoscope under virtual bronchoscopic navigation guidance). The primary outcome was detection of TB in BW fluid, defined as a positive result in the Xpert MTB/RIF assay. The secondary outcomes included AFB smear and Mycobacterium tuberculosis culture positivity, time to treatment initiation, and bronchoscopy-related complications.

RESULTS

In total, 85 participants were included in the final analysis (43 in the control group and 42 in the investigational group). Twenty-three and 29, respectively, were finally diagnosed with PTB. The TB detection rate in BW fluid was higher in the investigational group (72.4% vs 43.5%, P = .035). Mycobacterium tuberculosis culture positivity was also higher in the investigational group (79.3% vs 52.2%, P = .038). No participants required premature bronchoscopy termination because of complications. Of the participants with PTB, the time to treatment initiation was shorter in the investigational group (median, 2.0 days vs 4.0 days, P = .001).

CONCLUSIONS

BW using a thin bronchoscope increases the TB detection rate in patients with PTB compared to conventional bronchoscopy. Clinical Trials Registration.ȃNCT03802812.

Impact of molecular diagnostic tests on diagnostic and treatment delays in tuberculosis: a systematic review and meta-analysis

BACKGROUND

Countries with high TB burden have expanded access to molecular diagnostic tests. However, their impact on reducing delays in TB diagnosis and treatment has not been assessed. Our primary aim was to summarize the quantitative evidence on the impact of nucleic acid amplification tests (NAAT) on diagnostic and treatment delays compared to that of the standard of care for drug-sensitive and drug-resistant tuberculosis (DS-TB and DR-TB).

METHODS

We searched MEDLINE, EMBASE, Web of Science, and the Global Health databases (from their inception to October 12, 2020) and extracted time delay data for each test. We then analysed the diagnostic and treatment initiation delay separately for DS-TB and DR-TB by comparing smear vs Xpert for DS-TB and culture drug sensitivity testing (DST) vs line probe assay (LPA) for DR-TB. We conducted random effects meta-analyses of differences of the medians to quantify the difference in diagnostic and treatment initiation delay, and we investigated heterogeneity in effect estimates based on the period the test was used in, empiric treatment rate, HIV prevalence, healthcare level, and study design. We also evaluated methodological differences in assessing time delays.

RESULTS

A total of 45 studies were included in this review (DS = 26; DR = 20). We found considerable heterogeneity in the definition and reporting of time delays across the studies. For DS-TB, the use of Xpert reduced diagnostic delay by 1.79 days (95% CI - 0.27 to 3.85) and treatment initiation delay by 2.55 days (95% CI 0.54-4.56) in comparison to sputum microscopy. For DR-TB, use of LPAs reduced diagnostic delay by 40.09 days (95% CI 26.82-53.37) and treatment initiation delay by 45.32 days (95% CI 30.27-60.37) in comparison to any culture DST methods.

CONCLUSIONS

Our findings indicate that the use of World Health Organization recommended diagnostics for TB reduced delays in diagnosing and initiating TB treatment. Future studies evaluating performance and impact of diagnostics should consider reporting time delay estimates based on the standardized reporting framework.

Approaches for designing and delivering solid lipid nanoparticles of distinct antitubercular drugs

Tuberculosis (TB) is still the biggest infectious disease among adults globally, which effects the social and biological lives of patients as well as the economic liability of healthcare systems. Current treatment regime has challenges with drug resistant (MDR/XDR) strains and the failure of standard therapeutic interventions against these TB strains. In the recent years, several nanocarrier-based drug delivery systems developed (including lipid-based) with anti-tuberculosis drugs via targeted delivery to improve the therapeutic outcomes. In this review, we attempt to summarize on the composition of the reported solid lipid-based particles (SLNPs), their various production methodologies, and properties of the delivery system, and their influence on cellular and pharmacokinetic aspects are also discussed. Besides, we have highlighted anti-TB drugs delivering via lipid-based systems have shown promising outcomes, however clinical translation of such systems is still under investigation. Based on recent advancements and reports, it is recommended that future efforts be made to accelerate the translational development of lipid-based nanocarriers to improve TB treatment.

MDN-6, a Possible Therapeutic Candidate for Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis

Background: The rise of antibiotic-resistant Mycobacterium tuberculosis strains has accelerated the hunt for novel drugs for tuberculosis (TB). Objectives: This study identified a novel compound with strong anti-TB efficacy against several resistant M. tuberculosis strains from a chemical library of naphthoquinone derivatives. Methods: The identified chemical was designated as MDN-6 (methyl-1,4-bis(2-(diethylamino)ethoxy)-2-naphthoate). Results: It significantly inhibited all the tested Mycobacterium strains, including 24 clinically isolated resistant strains. The minimum inhibitory concentrations of MDN-6 were between 0.02 and 25 g/mL. It also had partially synergistic activity against extensively drug-resistant M. tuberculosis when coupled with rifampicin and streptomycin. Additionally, MDN-6 demonstrated a superior post-antibiotic effect over isoniazid and exhibited comparable inhibitory efficacy against Mycobacterium marinum and Mycobacterium kansasii. Besides the antimicrobial effect, MDN-6 had a 50% lethal dosage (LD50) of 279.1 mg/kg in female BALB/c mice. Conclusions: MDN-6 is a promising anti-TB therapeutic candidate against drug-resistant M. tuberculosis. However, further investigation is necessary to elucidate the action mechanism and assess the drug’s in vivo therapeutic potential.

A decade of approved first-in-class small molecule orphan drugs: Achievements, challenges and perspectives

In the past decade (2011-2020), there was a growing interest in the discovery and development of orphan drugs for the treatment of rare diseases. However, rare diseases only account for a population of 0.65‰-1‰ which usually occur with previously unknown biological mechanisms and lack of specific therapeutics, thus to increase the demands for the first-in-class (FIC) drugs with new biological targets or mechanisms. Considering the achievements in the past 10 years, a total of 410 drugs were approved by U.S. Food and Drug Administration (FDA), which contained 151 FIC drugs and 184 orphan drugs, contributing to make up significant numbers of the approvals. Notably, more than 50% of FIC drugs are developed as orphan drugs and some of them have already been milestones in drug development. In this review, we aim to discuss the FIC small molecules for the development of orphan drugs case by case and highlight the R&D strategy with novel targets and scientific breakthroughs.

Evaluation of early innate and adaptive immune responses to the TB vaccine Mycobacterium bovis BCG and vaccine candidate BCGΔBCG1419c

The vaccine Mycobacterium bovis Bacillus Calmette-Guérin (BCG) elicits an immune response that is protective against certain forms of tuberculosis (TB); however, because BCG efficacy is limited it is important to identify alternative TB vaccine candidates. Recently, the BCG deletion mutant and vaccine candidate BCGΔBCG1419c was demonstrated to survive longer in intravenously infected BALB/c mice due to enhanced biofilm formation, and better protected both BALB/c and C57BL/6 mice against TB-induced lung pathology during chronic stages of infection, relative to BCG controls. BCGΔBCG1419c-elicited protection also associated with lower levels of proinflammatory cytokines (i.e. IL6, TNFα) at the site of infection in C57BL/6 mice. Given the distinct immune profiles of BCG- and BCGΔBCG1419c-immunized mice during chronic TB, we set out to determine if there are early immunological events which distinguish these two groups, using multi-dimensional flow cytometric analysis of the lungs and other tissues soon after immunization. Our results demonstrate a number of innate and adaptive response differences between BCG- and BCGΔBCG1419c-immunized mice which are consistent with the latter being longer lasting and potentially less inflammatory, including lower frequencies of exhausted CD4⁺ T helper (T_H) cells and higher frequencies of IL10-producing T cells, respectively. These studies suggest the use of BCGΔBCG1419c may be advantageous as an alternative TB vaccine candidate.

Diagnostic Yield of Xpert MTB/RIF Assay Using Bronchoalveolar Lavage Fluid in Detecting Mycobacterium tuberculosis among the Sputum-Scarce Suspected Pulmonary TB Patients

Tuberculosis (TB) remains one of the leading causes of death worldwide and is caused by the single infectious agent Mycobacterium tuberculosis (Mtb). Although sputum is the most common specimen for pulmonary TB detection, some other respiratory specimens, such as bronchoalveolar lavage (BAL) fluid, gastric lavage (GL), and induced sputum (IS), are also collected from patients who are unable to deliver sputum. In this study, we aimed to evaluate the diagnostic performances of different test methods for TB diagnosis using BAL fluid specimens from sputum-scarce pulmonary TB patients. In this current study, a total of 210 BAL fluid specimens were collected and subjected to culture on Lowenstein–Jensen (L-J) medium, using an N-acetyl-L-cysteine-Sodium Hydroxide decontamination and digestion method, Xpert MTB/RIF (Xpert, Cepheid, Sunnyvale, CA, USA) assay, and acid-fast bacilli (AFB) microscopy with a Ziehl–Neelsen staining method for the detection of pulmonary TB. The sensitivity and specificity of these methods were then analyzed against the composite reference standard (CRS). Additionally, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of these assays. Among the 210 specimens, 39 (18.6%), 27 (12.8%), and 12 (5.7%) were found positive with Xpert assay, culture, and AFB microscopy, respectively. Considering the CRS, 42 (20%) were positive as the final diagnosis. The Xpert assay had a significantly higher sensitivity (92.9%, 95% CI: 80.5–98.5) compared to culture (64.3%, 95% CI: 48.0–78.4) and AFB microscopy (28.6%, 95% CI: 15.7–44.6) against the CRS. Additionally, the area under the ROC curve (AUC) for the Xpert assay, culture, and AFB microscopy accounted for 0.964, 0.821, and 0.655, respectively, when using CRS as the reference. In conclusion, our study findings demonstrated that the Xpert assay conferred a considerable diagnostic potential compared to other conventional methods for the diagnosis of pulmonary TB from BAL fluid specimens.

In vitro anti-tuberculosis effect of probiotic Lacticaseibacillus rhamnosus PMC203 isolated from vaginal microbiota

Mycobacterium tuberculosis (M. tb), the etiological agent of tuberculosis (TB), poses a severe challenge for public health and remains the number one cause of death as a single infectious agent. There are 10 million active cases of TB per year with 1.5 million deaths, and 2-3 billion people are estimated to harbor latent M. tb infection. Moreover, the emergence of multi-drug-resistant (MDR), extremely-drug-resistant (XDR), and the recent totally drug-resistant (TDR) M. tb is becoming a global issue that has fueled the need to find new drugs different from existing regimens. In these circumstances, probiotics can be a potential choice, so we focused on developing them as an anti-tuberculosis drug candidate. Here, we report the anti-tubercular activities of Lacticaseibacillus rhamnosus PMC203 isolated from the vaginal microbiota of healthy women. PMC203 exhibited a promising intracellular killing effect against both drug-sensitive and resistant M. tb infected murine macrophage cell line RAW 264.7 without showing any cytotoxicity. Additionally, it also inhibited the growth of M. tb under broth culture medium. PMC203 did not cause weight change or specific clinical symptoms in a 2-week repeated oral administration toxicity test in a guinea pig model. Here, we also found that PMC203 induces autophagy in a dose dependent manner by increasing the signal of well-known autophagy gene markers, suggesting a possible intracellular killing mechanism.

CYCLOBUTANES IN SMALL MOLECULE DRUG CANDIDATES

Cyclobutanes are increasingly used in medicinal chemistry in the search for relevant biological properties. Important characteristics of the cyclobutane ring include its unique puckered structure, longer C−C bond lengths, increased C−C π‐character and relative chemical inertness for a highly strained carbocycle. This review will focus on contributions of cyclobutane rings in drug candidates to arrive at favorable properties. Cyclobutanes have been employed for improving multiple factors such as preventing cis/trans‐isomerization by replacing alkenes, replacing larger cyclic systems, increasing metabolic stability, directing key pharmacophore groups, inducing conformational restriction, reducing planarity, as aryl isostere and filling hydrophobic pockets.

Polymorphisms of SLC11A1(NRAMP1) rs17235409 associated with and susceptibility to spinal tuberculosis in a southern Han Chinese population

OBJECTIVE

To investigate the association between SLC11A1 (NRAMP1) rs17235409 (D543N) polymorphisms and susceptibility to spinal tuberculosis (STB) in the Han population in southern China.

METHODS

This study included 227 STB patients and 516 controls. Polymorphisms of SLC11A1 rs17235409 were genotyped using a SNPscan™ kit, and the protein was detected by western blotting.

RESULTS

The genotype and allele frequency distributions of SLC11A1 rs17235409 differed significantly between the STB group and the control group(χ² = 17.650, P = 0.000). The distribution of GA genotype(GA vs. GG: P = 0.000, OR [95% CI] = 2.203[1.520-3.192] was significantly different between STB group and control group, but there was no significant difference in the distribution of AA genotypes(AA vs. GG: P = 0.889, OR [95%CI] = 0.674[0.142-3.208]). The A allele was more common in the STB group than in the control group (A vs. G: P = 0.001, OR [95%CI] = 1.767[1.273-2.452]). Under the dominant model, the GA + AA genotype was more common in the STB group than in the control group (GA + AA vs. GG: P = 0.000, OR [95%CI] = 2.067[1.438-2.971]). However, under the recessive model, there was no difference in GA + GG genotype between the STB and control groups(GA + GG vs. AA: P = 0.701, OR [95%CI] =1.772[0.373-8.409]). NRAMP1 protein expression in the STB group(n = 9) was significantly higher than that in the control group(n = 9) (t = 5.292,P = 0.001).

CONCLUSIONS

Variant genotypes at the rs17235409 locus of the SLC11A1 gene are associated with STB in the southern Han Chinese population. NRAMP1 protein expression is increased in patients with spinal tuberculosis, and the presence of the A allele increases the risk of developing STB.

Treatment outcomes of patients with MDR-TB and its determinants at referral hospitals in Ethiopia

BACKGROUND

There is limited empirical evidence in Ethiopia on the determinants of treatment outcomes of patients with multidrug-resistant tuberculosis (MDR-TB) who were enrolled to second-line anti-tuberculosis drugs. Thus, this study investigated the determinants of treatment outcomes in patients with MDR-TB at referral hospitals in Ethiopia.

DESIGN AND METHODS

This study was underpinned by a cross-sectional quantitative research design that guided both data collection and analysis. Data is collected using structured questionnaire and data analyses was performed using the Statistical Package for Social Sciences. Multi-variable logistic regression was used to control for confounders in determining the association between treatment outcomes of patients with MDR-TB and selected predictor variables, such as co-morbidity with MDR-TB and body mass index.

RESULTS

From the total of 136 patients with MDR-TB included in this study, 31% had some co-morbidity with MDR-TB at baseline, and 64% of the patients had a body mass index of less than 18.5 kg/m2. At 24 months after commencing treatment, 76 (69%), n = 110), of the patients had successfully completed treatment, while 30 (27%) died of the disease. The odds of death was significantly higher among patients with low body mass index (AOR = 2.734, 95% CI: 1.01-7.395; P<0.048) and those with some co-morbidity at baseline (AOR = 4.260, 95%CI: 1.607-11.29; p<0.004).

CONCLUSION

The higher proportion of mortality among patients treated for MDR-TB at Adama and Nekemte Hospitals, central Ethiopia, is attributable to co-morbidities with MDR-TB, including HIV/AIDS and malnutrition. Improving socio-economic and nutritional support and provision of integrated care for MDR-TB and HIV/AIDS is recommended to mitigate the higher level of death among patients treated for MDR-TB.

Identifying the analogues of berberine as promising antitubercular drugs targeting Mtb-FtsZ polymerisation through ligand-based virtual screening and molecular dynamics simulations

Berberine, an active compound in the extract of golden seal (an age-long remedy for many infections) has been confirmed to be responsible for the extract's activity against multi-drug resistant strain of Mycobacterium tuberculosis. There is no available study that shows the exact target of berberine in M tuberculosis, although it is confirmed that berberine inhibits the polymerisation of filamentous temperature-sensitive mutant Z (FtsZ), an important bacteria cytokinesis protein, in Escherichia coli, suggesting that FtsZ could as well be the target of berberine in M tuberculosis. In this study, we carried out ligand-based virtual screening to identify analogues of berberine followed by molecular dynamics (MD) simulations of the complexes of Mtb-FtsZ with berberine (berb1) and the five selected analogues (berb9 [ZINC1709414], berb37 [ZINC238749993], berb38 [ZINC13509022], berb43 [ZINC14765594], and berb48 [ZINC238758595]). Post-MD analyses such as binding free energy, RMSD, RMSF, RoG and hydrogen bond lifetime analysis were used to understand the interactions between these ligands and the receptor. The results suggested that Mtb-FtsZ could likely be the target of berberine in M tuberculosis as it forms a stable complex coupled with a significantly high binding energy. The study also identified other potential inhibitors of MTB-FtsZ polymerisation. Berb38 specifically showed greater interaction with the residues at the binding site of the protein, forming a far more stable complex with the receptor than any of the other compounds under investigation, including berberine itself. ADME properties calculations also predicted all the ligands to be bioactive as orally administered drugs.

e-Pharmacophore model-guided design of potential DprE1 inhibitors: synthesis, in vitro antitubercular assay and molecular modelling studies

Tuberculosis continues to wreak havoc worldwide and caused around 1.4 million deaths in 2019. Hence, in our pursuit of developing novel antitubercular compounds, we are reporting the e-Pharmacophore-based design of DprE1 (decaprenylphosphoryl-ribose 2′-oxidase) inhibitors. In the present work, we have developed a four-feature e-Pharmacophore model based on the receptor–ligand cavity of DprE1 protein (PDB ID 4P8C) and mapped our previous reported library of compounds against it. The compounds were ranked on phase screen score, and the insights obtained from their alignment were used to design some novel compounds. The designed compounds were docked with DprE1 protein in extra-precision mode using Glide module of Maestro, Schrodinger. Some derivatives like B1, B2, B4, B5 and B12 showed comparable docking score (docking score > − 6.0) with respect to the co-crystallized ligand. The designed compounds were synthesized and characterized. In vitro antitubercular activity was carried out on Mycobacterium tuberculosis H37Rv (ATCC27294) strain using the agar dilution method, and minimum inhibitory concentration (MIC) was determined. The compound B12 showed a MIC value of 1.56 μg/ml which was better than the standard drug ethambutol (3.125 μg/ml). Compounds B7 and B11 were found to be equipotent with ethambutol. Cytotoxicity studies against Vero cell lines proved that these compounds were non-cytotoxic. Molecular dynamic simulation study also suggests that compound B12 will form a stable complex with DprE1 protein and will show the crucial H-bond interaction with LYS418 residue. Further in vitro enzyme inhibition studies are required to validate these findings.

Molecular characterization of mutations associated with resistance to second line drugs in Mycobacterium tuberculosis patients from Casablanca, Morocco

The emergence and spread of extensively drug-resistant tuberculosis (XDR-TB) is a serious threat to global health. Therefore, its rapid diagnosis is crucial. The present study aimed to characterize mutations conferring resistance to second line drugs (SLDs) within multidrug Mycobacterium tuberculosis (MDR-MTB) isolates and to estimate the occurrence of XDR-TB in Casablanca, Morocco. A panel of 200 MDR-TB isolates was collected at the Pasteur Institute between 2015-2018. Samples were subjected to drug susceptibility testing to Ofloxacin (OFX), Kanamycin (KAN) and Amikacin (AMK). The mutational status of gyrA, gyrB, rrs, tlyA and eis was assessed by sequencing these target genes. Drug susceptibility testing for SLDs showed that among the 200 MDR strains, 20% were resistant to OFX, 2.5% to KAN and 1.5% to AMK. Overall, 14.5% of MDR strains harbored mutations in gyrA, gyrB, rrs and tlyA genes. From the 40 OFX^R isolates, 67.5% had mutations in QRDR of gyrA and gyrB genes, the most frequent one being Ala90Val in gyrA gene. Of note, none of the isolates harbored simultaneously mutations in gyrA and gyrB genes. In eight out of the 200 MDR-TB isolates resistant either to KAN or AMK, only 25% had A1401G or Lys89Glu change in rrs and tlyA genes respectively. This study is very informative and provides data on the alarming rate of fluoroquinolone resistance which warrants the need to implement appropriate drug regimens to prevent the emergence and spread of more severe forms of Mycobacterium tuberculosis drug resistance.

Trends in burden of multidrug-resistant tuberculosis in countries, regions, and worldwide from 1990 to 2017: results from the Global Burden of Disease study

Background

Antituberculosis-drug resistance is an important public health issue, and its epidemiological patterns has dramatically changed in recent decades. This study aimed to estimate the trends of multidrug-resistant tuberculosis (MDR-TB), which can be used to inform health strategies.

Methods

Data were collected from the Global Burden of Disease study 2017. The estimated annual percentage changes (EAPCs) were calculated to assess the trends of MDR-TB burden at global, regional, and national level from 1990 to 2017 using the linear regression model.

Results

Globally, the age-standardized rate (ASR) of MDR-TB burden including incidence, prevalence, death and disability-adjusted life years (DALYs) had pronounced increasing trends from 1990 to 1999, with the EAPCs were 17.63 [95% confidence interval (CI): 10.77–24.92], 17.57 (95% CI 11.51–23.95), 21.21 (95% CI 15.96–26.69), and 21.90 (95% CI 16.55–27.50), respectively. Particularly, the largest increasing trends were seen in areas and countries with low and low-middle sociodemographic index (SDI). However, the trends in incidence, prevalence, death and DALYs of MDR-TB decreased globally from 2000 to 2017, with the respective EAPCs were − 1.37 (95% CI − 1.62 to − 1.12), − 1.32 (95% CI − 1.38 to − 1.26), − 3.30 (95% CI − 3.56 to − 3.04) and − 3.32 (95% CI − 3.59 to − 3.06). Decreasing trends of MDR-TB were observed in most regions and countries, particularly that of death and DALYs in Slovenia were − 18.96 (95% CI − 20.82 to − 17.06) and -19.35 (95% CI − 21.10 to − 17.55), respectively. Whereas the pronounced increasing trends of MDR-TB occurred in Papua New Guinea, Singapore, and Australia.

Conclusions

The ASR of MDR-TB showed pronounced decreasing trends from 2000 to 2017. However, the MDR-TB burden remains a substantial challenge to the TB control globally, and requires effective control strategies and healthcare systems.

Lack of Weight Gain During the First 2 Months of Treatment and Human Immunodeficiency Virus Independently Predict Unsuccessful Treatment Outcomes in Tuberculosis

BACKGROUND

Weight change may inform tuberculosis treatment response, but its predictive power may be confounded by human immunodeficiency virus (HIV).

METHODS

We prospectively followed up adults with culture-confirmed, drug-susceptible, pulmonary tuberculosis receiving standard 4-drug therapy (isoniazid, rifampin, pyrazinamide, and ethambutol) in Brazil. We examined median weight change 2 months after treatment initiation by HIV status, using quantile regression, and unsuccessful tuberculosis treatment outcome (treatment failure, tuberculosis recurrence, or death) by HIV and weight change status, using Cox regression.

RESULTS

Among 547 participants, 102 (19%) were HIV positive, and 35 (6%) had an unsuccessful outcome. After adjustment for confounders, persons living with HIV (PLWH) gained a median of 1.3 kg (95% confidence interval [CI], -2.8 to .1) less than HIV-negative individuals during the first 2 months of tuberculosis treatment. PLWH were at increased risk of an unsuccessful outcome (adjusted hazard ratio, 4.8; 95% CI, 2.1-10.9). Weight change was independently associated with outcome, with risk of unsuccessful outcome decreasing by 12% (95% CI, .81%-.95%) per 1-kg increase.

CONCLUSIONS

PLWH gained less weight during the first 2 months of tuberculosis treatment, and lack of weight gain and HIV independently predicted unsuccessful tuberculosis treatment outcomes. Weight, an easily collected biomarker, may identify patients who would benefit from alternative treatment strategies.

Antimicrobial activity of IDD-B40 against drug-resistant Mycobacterium tuberculosis

The emergence of multi-drug resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis creates the urgency for new anti-tuberculosis drugs to improve the efficiency of current tuberculosis treatment. In the search for a new potential tuberculosis drug, we synthesized an isoindole based chemical library and screened a potential candidate with significant anti-tuberculosis activity. The compound named 2-hydroxy-4-(4-nitro-1,3-dioxoisoindolin-2-yl) benzoic acid (IDD-B40) showed strong activity against all the tested drug-susceptible and drug-resistant strains of M. tuberculosis, with the 50% minimum inhibitory concentrations (MIC₅₀) of 0.39 μg/ml both in culture broth and inside Raw 264.7 cells. Also, IDD-B40, in combination with rifampicin, exhibited a direct synergistic effect against both XDR and H37Rv M. tuberculosis. Besides, IDD-B40 showed a better post-antibiotic effect (PAE) than did some first-line drugs and showed no significant cytotoxicity to any cell line tested, with a selectivity index of ≥ 128. Although IDD-B40 showed a result similar to isoniazid in the preliminary mycolic acid inhibition assay, it did not exhibit any effect against other mycolic acid-producing nontuberculous mycobacterial strains (NTM), and different non-mycobacterial pathogenic strains, so further studies are required to confirm the mode of action of IDD-B40. Considering its results against M. tuberculosis, IDD-B40 is a potential anti-tuberculosis drug candidate. However, further studies are required to evaluate its potential in vivo effect and therapeutic potential.

The impact of human vaccines on bacterial antimicrobial resistance. A review

At present, the dramatic rise in antimicrobial resistance (AMR) among important human bacterial pathogens is reaching a state of global crisis threatening a return to the pre-antibiotic era. AMR, already a significant burden on public health and economies, is anticipated to grow even more severe in the coming decades. Several licensed vaccines, targeting both bacterial (Haemophilus influenzae type b, Streptococcus pneumoniae, Salmonella enterica serovar Typhi) and viral (influenza virus, rotavirus) human pathogens, have already proven their anti-AMR benefits by reducing unwarranted antibiotic consumption and antibiotic-resistant bacterial strains and by promoting herd immunity. A number of new investigational vaccines, with a potential to reduce the spread of multidrug-resistant bacterial pathogens, are also in various stages of clinical development. Nevertheless, vaccines as a tool to combat AMR remain underappreciated and unfortunately underutilized. Global mobilization of public health and industry resources is key to maximizing the use of licensed vaccines, and the development of new prophylactic vaccines could have a profound impact on reducing AMR.

Design, synthesis, and biological evaluation of benzo[d]imidazole-2-carboxamides as new anti-TB agents

Tuberculosis is the leading cause of death globally among infectious diseases. Due to the development of resistance of Mycobacterium tuberculosis to currently used anti-TB medicines and the TB-HIV synergism the urgent need to develop novel anti-mycobacterial agents has been realized. The drug-to-target path has been the successful strategy for new anti-TB drug development. All the six drug candidates that have shown promise during the clinical trials and some of these being approved for treatment against MDR TB are the results of phenotype screening of small molecule compound libraries. In search of compounds belonging to novel pharmacophoric class that could be subjected to whole cell assay to generate new anti-TB leads the benzo[d]imidazole-2-carboxamide moiety has been designed as a novel anti-TB scaffold. The design was based on the identification of the benzimidazole ring as a prominent substructure of the FDA approved drugs, the structural analysis of reported anti-TB benzimidazoles, and the presence of the C-2 carboxamido functionality in novel bioisoteric anti-TB benzothiazoles. Twenty seven final compounds have been prepared via NH₄Cl-catalyzed amidation of ethyl benzo[d]imidazole-2-carboxylates, as the required intermediates, obtained through a green "all water" one-pot synthetic route following a tandem N-arylation-reduction-cyclocondensation procedure. All of the synthesised target compounds were assessed for anti-TB potential using H₃₇Rv ATCC27294 strain. Thirteen compounds were found with better MIC (0.78-6.25 µg/mL) than the standard drugs and being non-cytotoxic nature (<50% inhibition against RAW 264.7 cell lines at 50 µg/mL). The compound 8e exhibited best anti-TB activity (MIC: 2.15 µM and selectivity index: > 60) and a few others e.g., 8a, 8f, 8k and 8o are the next best anti-TB hits (MIC: 1.56 µg/mL). The determination and analysis of various physiochemical parameters revealed favorable druglike properties of the active compounds. The compounds 8a-l and 8o, with MIC values of ≤ 6.25 μg/mL, have high LipE values (10.66-11.77) that are higher than that of the suggested value of > 6 derived from empirical evidence for quality drug candidates and highlight their therapeutic potential. The highest LipE value of 11.77 of the best active compound 8e with the MIC of 0.78 μg/mL indicates its better absorption and clearance as a probable clinical candidate for anti-TB drug discovery. These findings highlight the discovery of benzimidazole-2-carboxamides for further development as new anti-TB agents.

Retroperitoneoscopic Drainage of Psoas Abscess: A Systematic Review

BACKGROUND

Psoas abscess is a relatively rare clinical condition that can occur worldwide, is difficult to diagnose, and has a severe clinical course. Conventional treatment ranges from antibiotic therapy alone to computed tomography (CT)-guided and/or open surgical drainage. Retroperitoneoscopic drainage represents a minimally invasive and potentially definitive therapeutic option.

MATERIALS AND METHODS

A systematic review of the literature on minimally invasive extraperitoneal access for drainage of psoas abscess was conducted through PUBMED, EMBASE, and COCHRANE databases, according to the PRISMA statement guidelines. We considered only studies in English and with a full text. The quality of all selected articles was assessed for the risk of methodological bias. Additional literature sources were used to put into context the indications and limits of retroperitoneoscopic drainage.

RESULTS

Seven papers published between 2004 and 2020, including a total of 56 patients, met the eligibility criteria and were included in the qualitative analysis. Causative agents of psoas abscess included Mycobacterium tuberculosis, Klebsiella pneumoniae, Enterobacter aerogenes, Staphylococcus aureus, and Streptococcus spp. Tuberculous abscess was more common than pyogenic abscess (92.8% vs. 7.2%). Main clinical findings were back pain (76.8%) and fever (53.6%). All patients were preoperatively evaluated by CT or magnetic resonance imaging. Only 4 patients (7.1%) had previously undergone CT-guided percutaneous drainage. Retroperitoneoscopic drainage was combined with antibiotic therapy in all cases. No Clavien-Dindo grade >3 complications occurred, and there was no 30-day postoperative mortality. The recurrence rate was 1.8% at a mean follow-up of 21 months.

CONCLUSION

Retroperitoneoscopic surgical drainage is a safe and effective approach for the treatment of psoas abscess.

Probing the dual inhibitory mechanisms of novel thiophenecarboxamide derivatives against Mycobacterium tuberculosis PyrG and PanK: an insight from biomolecular modeling study

The growing occurrence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis (Mtb) strains underscores an urgent need for new antibiotics. The development of more bioactive antibiotics against drug-resistant organisms with a different mode of action could be a game-changer for the cure and eradication of tuberculosis (TB). Pantothenate Kinase (PanK) and CTP synthetase (PyrG) are both essential for RNA, DNA, and Lipids biosynthesis pathways. Given the extensive knowledge on these biosynthesis pathways inhibition of Mtb growth and survival, these enzymes present a fascinating opportunity for anti-mycobacterial drug discovery. Recently, it was experimentally established that the active metabolite 11426026 of compound 7947882 (a prodrug activated by EthA monooxygenase, 5-methyl-N-(4-nitrophenyl) thiophene-2-carboxamide) inhibits the activities of PyrG and PanK to indicate novel multitarget therapy aimed at discontinuing Mtb growth. However, the molecular mechanisms of their selective inhibition remain subtle. In this work, molecular dynamics simulations were employed to investigate the inhibitory mechanism as well as the selectivity impact of the active metabolite inhibitor of these enzymes. Computational modeling of the studied protein-ligand systems reveals that the active metabolite can potentially inhibit both PanK and PyrG, thereby creating a pathway as a double target approach in tuberculosis treatment.Communicated by Ramaswamy H. Sarma.

Minimally invasive surgery for paravertebral or psoas abscess with spinal tuberculosis - a long-term retrospective study of 106 cases

Background

Minimally invasive surgery (MIS) is a common treatment option for paravertebral or psoas abscesses (PAs) in patients with spinal tuberculosis (ST). However, its efficacy remains controversial. The aim of the study was to evaluate the efficacy of MIS for PA with ST combined with anti-tuberculous chemotherapy.

Methods

A total of 106 consecutive patients who underwent MIS for ST with PA from January 2002 to Oct 2012 were reviewed. The MIS involved computed tomography (CT)-guided percutaneous catheter drainage and percutaneous catheter infusion chemotherapy. Clinical outcomes were evaluated based on the changes observed on preoperative and postoperative physical examination, inflammatory marker testing, and magnetic resonance imaging (MRI).

Results

The mean follow-up period was 7.21 ± 3.15 years. All surgeries were successfully completed under CT-guidance without intraoperative complications and all patients experienced immediate relief of their symptoms, which included fever and back pain. The preoperatively elevated erythrocyte sedimentation rate and C-reactive protein values returned to normal at a mean period of 3 months postoperatively. Solid bony union was observed in 106 patients and no abscesses were found on MRI examination.

Conclusion

MIS carries advantages in terms of less invasiveness, precise drainage, and enhanced local drug concentration. While the technique has not been fully characterized and clinically prove, its use in addition to conservative chemotherapy and open debridement and instrumental fixation may be recommended for patients with ST and PA.

Using Selection by Nonantibiotic Stressors to Sensitize Bacteria to Antibiotics

Evolutionary adaptation of bacteria to nonantibiotic selective forces, such as osmotic stress, has been previously associated with increased antibiotic resistance, but much less is known about potentially sensitizing effects of nonantibiotic stressors. In this study, we use laboratory evolution to investigate adaptation of Enterococcus faecalis, an opportunistic bacterial pathogen, to a broad collection of environmental agents, ranging from antibiotics and biocides to extreme pH and osmotic stress. We find that nonantibiotic selection frequently leads to increased sensitivity to other conditions, including multiple antibiotics. Using population sequencing and whole-genome sequencing of single isolates from the evolved populations, we identify multiple mutations in genes previously linked with resistance to the selecting conditions, including genes corresponding to known drug targets or multidrug efflux systems previously tied to collateral sensitivity. Finally, we hypothesized based on the measured sensitivity profiles that sequential rounds of antibiotic and nonantibiotic selection may lead to hypersensitive populations by harnessing the orthogonal collateral effects of particular pairs of selective forces. To test this hypothesis, we show experimentally that populations evolved to a sequence of linezolid (an oxazolidinone antibiotic) and sodium benzoate (a common preservative) exhibit increased sensitivity to more stressors than adaptation to either condition alone. The results demonstrate how sequential adaptation to drug and nondrug environments can be used to sensitize bacteria to antibiotics and highlight new potential strategies for exploiting shared constraints governing adaptation to diverse environmental challenges.

Diagnostic value of bronchoalveolar lavage and bronchial washing in sputum-scarce or smear-negative cases with suspected pulmonary tuberculosis: a randomized study

OBJECTIVES

Bronchoalveolar lavage (BAL) and bronchial washing (BW) are two major methods used to obtain high-quality respiratory specimens from patients with suspected pulmonary tuberculosis (TB) but a sputum-scarce or smear-negative status. We aimed to compare the value of BAL and BW in the diagnosis of TB in such patients.

METHODS

We enrolled patients with suspected pulmonary TB but with a sputum-scarce or smear-negative status who were referred for bronchoscopy between October 2013 and January 2016. Participants were randomized into the BAL and BW groups for evaluation. The primary outcome was the diagnostic yield for TB detection. Secondary outcomes included culture positivity, positivity of nucleic acid amplification tests (NAATs) for Mycobacterium tuberculosis and procedure-related complications.

RESULTS

A total of 94 patients were assessed and 91 (43 in the BAL group, 48 in the BW group) were analysed. Twenty-one patients (48.8%) in the BAL group and 30 (62.5%) in the BW group had a final diagnosis of pulmonary TB. The detection rate of M. tuberculosis by culture or NAAT was significantly higher in BAL specimens than in BW specimens (85.7% vs 50.0%, p 0.009). The procedure-related complications were hypoxic events, 2/43 (4.7%) in the BAL group and 5/48 (10.4%) in the BW group; and post-bronchoscopic fever, 3/43 (7.0%) in the BAL group and 4/48 (8.3%) in the BW group.

DISCUSSION

As long as it is tolerable, BAL rather than BW, should be used to obtain specimens for the diagnosis of pulmonary TB in sputum-scarce or smear-negative cases.

Cost-effectiveness of QuantiFERON-TB Gold In-Tube versus tuberculin skin test for diagnosis and treatment of Latent Tuberculosis Infection in primary health care workers in Brazil

Objectives

The goal of this study was to perform a cost-effectiveness analysis from the public health system perspective, comparing five strategies for Latent Tuberculosis Infection (LTBI) diagnosis in primary health care workers in Brazil.

Design

Analytical model for decision making, characterized by cost-effectiveness analysis.

Setting

Primary Care Level, considering primary health care workers in Brazil.

Participants

An analytical model for decision making, characterized by a tree of probabilities of events, was developed considering a hypothetical cohort of 10,000 primary health care workers, using the software TreeAge Pro^™ 2013 to simulate the clinical and economic impacts of new diagnostic technology (QuantiFERON^®-TB Gold in-Tube) versus the traditional tuberculin skin test.

Methods

This model simulated five diagnostic strategies for LTBI in primary health care workers (HCW) in Brazil: tuberculin skin testing using ≥5 mm cut-off, tuberculin skin testing ≥10 mm cut-off, QuantiFERON^®-TB Gold in-Tube, tuberculin skin testing using ≥5 mm cut-off confirmed by QuantiFERON^®-TB Gold In-Tube if TST positive, tuberculin skin testing using ≥10 mm cut-off confirmed by QuantiFERON^®-TB Gold In-Tube if TST positive.

Primary and secondary outcome measures

The outcome measures are the number of individuals correctly classified by the test and the number of Tuberculosis cases avoided.

Results

The most cost-effective strategy was the tuberculin skin test considering ≥10mm cut-off. The isolated use of the QuantiFERON^®-TB Gold In-Tube revealed the strategy of lower efficiency with incremental cost-effectiveness ratio (ICER) of US$ 146.05 for each HCW correctly classified by the test.

Conclusions

The tuberculin skin test using ≥10 mm cut-off was the most cost-effective strategy in the diagnosis of Latent Tuberculosis Infection in primary health care works in Brazil.

Pervasive and diverse collateral sensitivity profiles inform optimal strategies to limit antibiotic resistance

Evolved resistance to one antibiotic may be associated with "collateral" sensitivity to other drugs. Here, we provide an extensive quantitative characterization of collateral effects in Enterococcus faecalis, a gram-positive opportunistic pathogen. By combining parallel experimental evolution with high-throughput dose-response measurements, we measure phenotypic profiles of collateral sensitivity and resistance for a total of 900 mutant-drug combinations. We find that collateral effects are pervasive but difficult to predict because independent populations selected by the same drug can exhibit qualitatively different profiles of collateral sensitivity as well as markedly different fitness costs. Using whole-genome sequencing of evolved populations, we identified mutations in a number of known resistance determinants, including mutations in several genes previously linked with collateral sensitivity in other species. Although phenotypic drug sensitivity profiles show significant diversity, they cluster into statistically similar groups characterized by selecting drugs with similar mechanisms. To exploit the statistical structure in these resistance profiles, we develop a simple mathematical model based on a stochastic control process and use it to design optimal drug policies that assign a unique drug to every possible resistance profile. Stochastic simulations reveal that these optimal drug policies outperform intuitive cycling protocols by maintaining long-term sensitivity at the expense of short-term periods of high resistance. The approach reveals a new conceptual strategy for mitigating resistance by balancing short-term inhibition of pathogen growth with infrequent use of drugs intended to steer pathogen populations to a more vulnerable future state. Experiments in laboratory populations confirm that model-inspired sequences of four drugs reduce growth and slow adaptation relative to naive protocols involving the drugs alone, in pairwise cycles, or in a four-drug uniform cycle.

Mycobacterium tuberculosis Drug Resistance and Transmission among Human Immunodeficiency Virus-Infected Patients in Ho Chi Minh City, Vietnam

Vietnam has a high burden of tuberculosis (TB) and multidrug-resistant (MDR) TB, but drug resistance patterns and TB transmission dynamics among TB/human immunodeficiency virus (HIV) coinfected patients are not well described. We characterized 200 Mycobacterium tuberculosis isolates from TB/HIV coinfected patients diagnosed at the main TB referral hospital in Ho Chi Minh City, Vietnam. Phenotypic drug susceptibility testing (DST) for first-line drugs, spoligotyping, and 24-locus mycobacterial interspersed repetitive unit (MIRU-24) analysis was performed on all isolates. The 24-locus mycobacterial interspersed repetitive unit clusters and MDR isolates were subjected to whole genome sequencing (WGS). Most of the TB/HIV coinfected patients were young (162/174; 93.1% aged < 45 years) males (173; 86.5% male). Beijing (98; 49.0%) and Indo-Oceanic (70; 35.0%) lineage strains were most common. Phenotypic drug resistance was detected in 84 (42.0%) isolates, of which 17 (8.5%) were MDR; three additional MDR strains were identified on WGS. Strain clustering was reduced from 84.0% with spoligotyping to 20.0% with MIRU-24 typing and to 13.5% with WGS. Whole genome sequencing identified five additional clusters, or members of clusters, not recognized by MIRU-24. In total, 13 small (two to three member) WGS clusters were identified, with less clustering among drug susceptible (2/27; 7.4%) than among drug-resistant strains (25/27; 92.6%). On phylogenetic analysis, strains from TB/HIV coinfected patients were interspersed among strains from the general community; no major clusters indicating transmission among people living with HIV were detected. Tuberculosis/HIV coinfection in Vietnam was associated with high rates of drug resistance and limited genomic evidence of ongoing M. tuberculosis transmission among HIV-infected patients.

The impact of increased reimbursement rates under the new cooperative medical scheme on the financial burden of tuberculosis patients

Background

Tuberculosis (TB) is still a major public health problem in China. To scale up TB control, an innovative programme entitled the ‘China-Gates Foundation Collaboration on TB Control in China was initiated in 2009. During the second phase of the project, a policy of increased reimbursement rates under the New Cooperative Medical Scheme (NCMS) was implemented. In this paper, we aim to explore how this reform affects the financial burden on TB patients through comparison with baseline data.

Methods

In two cross-sectional surveys, quantitative data were collected before (January 2010 to December 2012) and after (April 2014 to June 2015) the intervention in the existing NCMS routine data system. Information on all 313 TB inpatients, among which 117 inpatients in the project was collected. Qualitative data collection included 11 focus group discussions. Three main indicators, non-reimbursable expenses rate (NER), effective reimbursement rate (ERR), and out-of-pocket payment (OOP) as a percentage of per capita household income, were used to measure the impact of intervention by comprising post-intervention data with baseline data. The quantitative data were analysed by descriptive analysis and non-parametric tests (Mann-Whitney U test) using SPSS 22.0, and qualitative data were subjected to thematic framework analysis using Nvivo10.

Results

The nominal reimbursement rates for inpatient care were no less than 80% for services within the package. Total inpatient expenses greatly increased, with an average growth rate of 11.3%. For all TB inpatients, the ERR for inpatient care increased from 52 to 66%. Compared with inpatients outside the project, for inpatients covered by the new policy, the ERR was higher (78%), and OOP showed a sharper decline. In addition, their financial burden decreased significantly.

Conclusions

Although the nominal reimbursement rates for inpatient care of TB patients greatly increased under the new reimbursement policy, inpatient OOP expenditure was still a major financial problem for patients. Limited diagnosis and treatment options in county general hospitals and inadequate implementation of the new policy resulted in higher inpatient expenditures and limited reimbursement. Comprehensive control models are needed to effectively decrease the financial burden on all TB patients.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0575-z) contains supplementary material, which is available to authorized users.

A Comprehensive Review on the Therapeutic Versatility of Imidazo [2,1-b]thiazoles

BACKGROUND

Imidazo[2,1-b]thiazole, a well-known fused five-membered hetrocycle is one of the most promising and versatile moieties in the area of medicinal chemistry. Derivatives of imidazo[2,1-b]thiazole have been investigated for the development of new derivatives that exhibit diverse pharmacological activities. This fused heterocycle is also a part of a number of therapeutic agents.

OBJECTIVE

To review the extensive pharmacological activities of imidazo[2,1-b]thiazole derivatives and the new molecules developed between 2000-2018 and their usefulness.

METHOD

Thorough literature review of all relevant papers and patents was conducted.

CONCLUSION

The present review, covering a number of aspects, is expected to provide useful insights in the design of imidazo[2,1-b]thiazole-based compounds and would inspire the medicinal chemists for a comprehensive and target-oriented information to achieve a major breakthrough in the development of clinically viable candidates.

Forecasting the seasonality and trend of pulmonary tuberculosis in Jiangsu Province of China using advanced statistical time-series analyses

Objective

Forecasting the seasonality and trend of pulmonary tuberculosis is important for the rational allocation of health resources; however, this foresting is often hampered by inappropriate prediction methods. In this study, we performed validation research by comparing the accuracy of the autoregressive integrated moving average (ARIMA) model and the back-propagation neural network (BPNN) model in a southeastern province of China.

Methods

We applied the data from 462,214 notified pulmonary tuberculosis cases registered from January 2005 to December 2015 in Jiangsu Province to modulate and construct the ARIMA and BPNN models. Cases registered in 2016 were used to assess the prediction accuracy of the models. The root mean square error (RMSE), mean absolute percentage error (MAPE), mean absolute error (MAE) and mean error rate (MER) were used to evaluate the model fitting and forecasting effect.

Results

During 2005–2015, the annual pulmonary tuberculosis notification rate in Jiangsu Province was 56.35/100,000, ranging from 40.85/100,000 to 79.36/100,000. Through screening and comparison, the ARIMA (0, 1, 2) (0, 1, 1)₁₂ and BPNN (3-9-1) were defined as the optimal fitting models. In the fitting dataset, the RMSE, MAPE, MAE and MER were 0.3901, 6.0498, 0.2740 and 0.0608, respectively, for the ARIMA (0, 1, 2) (0, 1, 1)₁₂ model, 0.3236, 6.0113, 0.2508 and 0.0587, respectively, for the BPNN model. In the forecasting dataset, the RMSE, MAPE, MAE and MER were 0.1758, 4.6041, 0.1368 and 0.0444, respectively, for the ARIMA (0, 1, 2) (0, 1, 1)₁₂ model, and 0.1382, 3.2172, 0.1018 and 0.0330, respectively, for the BPNN model.

Conclusion

Both the ARIMA and BPNN models can be used to predict the seasonality and trend of pulmonary tuberculosis in the Chinese population, but the BPNN model shows better performance. Applying statistical techniques by considering local characteristics may enable more accurate mathematical modeling.

The Application of Xpert Mycobacterium tuberculosis/Rifampicin, Quantitative Polymerase Chain Reaction and High Resolution Melting Curve in the Diagnosis of Superficial Lymph Node TB

OBJECTIVE

The diagnostic sensitivity and specificity of conventional methods for superficial lymph node tuberculosis (LNTB) are not ideal. We evaluated several novel methods including Xpert Mycobacterium tuberculosis/rifampicin (Xpert MTB/RIF) technology, quantitative fluorescence Polymerase Chain Reaction (qPCR) and High-Resolution Melting Curve (HRMC) in the diagnosis of superficial lymph node TB.

METHODS

Specimens from eighty-one consecutive patients with suspected LNTB and thirteen cases with other lymph node disease were analyzed by Xpert MTB/RIF, qPCR, and HRMC.

RESULTS

Among 81 patients with clinical suspicion of LNTB, there were 74 (91.4%) cases positive Mycobacterium tuberculosis Complex (MTBC) of Xpert MTB/RIF, 60 (74%) positive of qPCR, 24 (29.6%) of positive of BACTEC MGIT960 culture, and 13 (16%) cases positive of Roche culture. 38 cases (46.9%) were diagnosed with LNTB. All test methods showed a diagnostic specificity of 100% for LNTB. The sensitivity of molecular biology techniques was significantly higher than that of the traditional diagnostic methods, and Xpert MTB/RIF was the most sensitive diagnostic assay. On Rifampinresistant detection, Xpert MTB/RIF detected three cases (3.7%) with rpoB gene mutation, and Mycobacterium tuberculosis susceptibility testing detected 2 rifampicin-resistant cases (2.4%) which were consistent with Xpert MTB/RIF results. In the Isoniazid-resistant, 7 cases (8.1) of isoniazid resistance mutations (8.1%) were detected by HNC and 1 case was confirmed by Isoniazid susceptibility test.

CONCLUSION

Molecular detection increased the diagnostic sensitivity of LNTB and improved the detection sensitivity for rifampin and isoniazid resistance strain.

Delay in seeking care for tuberculosis symptoms among adults newly diagnosed with HIV in rural Malawi

SETTING:

Ten primary health clinics in rural Thyolo District, Malawi.

OBJECTIVE :

Tuberculosis (TB) is a common initial presentation of human immunodeficiency virus (HIV) infection. We investigated the time from TB symptom onset to HIV diagnosis to describe TB health-seeking behaviour in adults newly diagnosed with HIV.

DESIGN :

We asked adults (⩾18 years) about the presence and duration of TB symptoms at the time of receiving a new HIV diagnosis. Associations with delayed health seeking (defined as >30 and >90 days from the onset of TB symptoms) were evaluated using multivariable logistic regression.

RESULTS :

TB symptoms were reported by 416 of 1265 participants (33%), of whom 36% (150/416) had been symptomatic for >30 days before HIV testing. Most participants (260/416, 63%) were below the poverty line (US$0.41 per household member per day). Patients who first sought care from informal providers had an increased odds of delay of >30 days (adjusted odds ratio [aOR] 1.6, 95%CI 0.9–2.8) or 90 days (aOR 2.0, 95%CI 1.1–3.8).

CONCLUSIONS :

Delayed health seeking for TB-related symptoms was common. Poverty was ubiquitous, but had no clear relationship to diagnostic delay. HIV-positive individuals who first sought care from informal providers were more likely to experience diagnostic delays for TB symptoms.

Kelley H, Scordo JM, Hunt WG, Pan X, Balada-Llasat JM, Gebreyes W, Evans CA, Aseffa A, Torrelles JB, Wang SH, Abebe T. Evaluation of the tuberculosis culture color plate test for rapid detection of drug susceptible and drug-resistant Mycobacterium tuberculosis in a resource-limited setting, Addis Ababa, Ethiopia

Timely diagnosis of tuberculosis (TB) is limited in Ethiopia. We evaluated the performance of a low technology, thin layer agar, Mycobacterium tuberculosis (M.tb) culture color plate (TB-CX) test with concurrent drug susceptibility testing (DST) to isoniazid (INH), rifampin (RIF), and pyrazinamide (PZA) directly from sputum specimens. Patients undergoing examination for TB and multidrug-resistant (MDR)-TB were enrolled in Addis Ababa, Ethiopia from March 2016 to February 2017. All subjects received a GeneXpert MTB/RIF PCR test. TB-CX test results were compared to reference Löwenstein–Jensen (LJ) culture for M.tb detection and DST for susceptibility to INH and RIF. Kappa statistic was applied to test agreement between results for TB-CX test and the reference methods, a cut-off Kappa value of 0.75 was considered as high level of agreements. A total of 137 participants were analyzed: 88 (64%) were new TB cases, 49 (36%) were re-treatment cases. The TB-CX test detected M.tb and DST in an average of 13 days compared to 50 days for the conventional DST result. The sensitivity and specificity of the TB-CX test for detecting M.tb were 94% and 98%, respectively (concordance, 96%; kappa 0.91). The sensitivity of the TB-CX test to detect drug resistance to INH, RIF, and MDR-TB was 91%, 100%, and 90% respectively. The specificity of the TB-CX test for detecting INH, RIF, and MDR-TB was 94%, 40%, and 94% respectively. Overall agreement between TB-CX test and LJ DST for detection of MDR-TB was 93%. The TB-CX test showed strong agreement with the GeneXpert test for detecting M.tb (89%, kappa 0.76) but low agreement for the detection of RIF resistance (57%, kappa 0.28). The TB-CX test was found to be a good alternative method for screening of TB and selective drug resistant-TB in a timely and cost-efficient manner.

[Prevalence of tuberculosis in incarcerated populations: systematic review and meta-analysisPrevalencia de tuberculosis en la población privada de libertad: revisión sistemática y metanálisis]

Objetivo

Estimar a prevalência de tuberculose entre a população privada de liberdade.

Métodos

Realizou-se uma revisão sistemática com metanálise. Foram selecionados estudos publicados de janeiro de 1997 a dezembro de 2016 nas bases de dados MEDLINE (via PubMed), SciELO e LILACS. O termos de busca foram (“tuberculosis”[MeSH] OR “tuberculosis”[TIAB]) AND (“prisons”[MeSH] OR “prisons”[TIAB]); ou (“tuberculose” [DeCS] OU “tuberculose” [palavras] E “prisões” [DeCS] OU “prisões” [palavras]). O desfecho primário foi a prevalência de tuberculose com intervalo de confiança de 95% (IC95%). Na metanálise, as variáveis associadas com as taxas de prevalência de tuberculose na população privada de liberdade na análise univariada (P ≤ 0,20) foram incluídas no modelo final multivariado.

Resultados

Com base nos 29 estudos incluídos na metanálise, 2 163 presos foram identificados com tuberculose. A prevalência combinada de tuberculose entre os prisioneiros foi de 2% (IC95%: 0,02 a 0,02). A prevalência de tuberculose entre prisioneiros em países com prevalência de 0 a 24 por 100 mil habitantes na população geral ficou abaixo de 1% (IC95% = 0,00 a 0,00). Nos países com prevalência de tuberculose de 25 a 99/100 mil, a estimativa foi de 3% (IC95% = 0,02 a 0,04); e nos países com prevalência ≥ 300/100 mil, a estimativa foi de 8% (IC95% = 0,05 a 0,11).

Conclusão

O presente estudo reafirma a alta magnitude da tuberculose entre a população privada de liberdade no contexto mundial. Os resultados mostram ainda uma ligação entre a prevalência de tuberculose na população geral e a prevalência da doença dentro dos presídios.

γ-herpesvirus latency attenuates Mycobacterium tuberculosis infection in mice

Tuberculosis is caused by Mycobacterium tuberculosis (Mtb), a bacterial pathogen which is transmitted via aerosol and establishes a chronic lung infection. In naïve hosts, Mtb grows for several weeks without being restricted by IFNγ-producing T cells, which eventually accumulate and limit Mtb dissemination. In this study, we used a mouse model of Mtb/γ-herpesvirus (γHV) coinfection to test the hypothesis that latent γHV infection alters host resistance to Mtb. γHVs are DNA viruses which elicit a polyclonal T cell response and attenuate some acute bacterial pathogens in mice; whether γHVs modulate infection with Mtb is unknown. Here, mice harboring latent mouse gammaherpesvirus 68 (MHV68)-a γHV genetically and biologically related to human Epstein Barr virus (EBV)-were infected via aerosol with a low dose of virulent Mtb. Mtb burdens and IFNγ⁺ T cell frequencies in mice with latent MHV68 (MHV68^POS mice) were subsequently measured and compared to control mice that did not harbor latent MHV68 (MHV68^NEG mice). Relative to MHV68^NEG controls, MHV68^POS mice more effectively limited Mtb growth and dissemination, and had higher frequencies of CD4+IFNγ+ cells in lung-draining lymph nodes. Collectively, our results support a model wherein latent γHV confers moderate protection against subsequent Mtb infection.