Tuberculosis and HIV co-infection. PLoS Pathog. 2012;8:e1002464. [PMID: 22363214 PMCID: PMC3280977 DOI: 10.1371/journal.ppat.1002464]

The metabolic consequences of HIV/TB co-infection

BACKGROUND

The synergy between the human immunodeficiency virus (HIV) and Mycobacterium tuberculosis during co-infection of a host is well known. While this synergy is known to be driven by immunological deterioration, the metabolic mechanisms that contribute to the associated disease burden experienced during HIV/tuberculosis (TB) co-infection remain poorly understood. Furthermore, while anti-HIV treatments suppress viral replication, these therapeutics give rise to host metabolic disruption and adaptations beyond that induced by only infection or disease.

METHODS

In this study, the serum metabolic profiles of healthy controls, untreated HIV-negative TB-positive patients, untreated HIV/TB co-infected patients, and HIV/TB co-infected patients on antiretroviral therapy (ART), were measured using two-dimensional gas chromatography time-of-flight mass spectrometry. Since no global metabolic profile for HIV/TB co-infection and the effect of ART has been published to date, this pilot study aimed to elucidate the general areas of metabolism affected during such conditions.

RESULTS

HIV/TB co-infection induced significant changes to the host's lipid and protein metabolism, with additional microbial product translocation from the gut to the blood. The results suggest that HIV augments TB synergistically, at least in part, contributing to increased inflammation, oxidative stress, ART-induced mitochondrial damage, and its detrimental effects on gut health, which in turn, affects energy availability. ART reverses these trends to some extent in HIV/TB co-infected patients but not to that of healthy controls.

CONCLUSION

This study generated several new hypotheses that could direct future metabolic studies, which could be combined with other research techniques or methodologies to further elucidate the underlying mechanisms of these changes.

Neuromeningeal Cryptococcosis and Tuberculosis Coinfection in Bamako: A One-Year Case Series

Cryptococcosis and tuberculosis are life-threatening opportunistic infections that occur in apparently immunocompetent or severely immunocompromised individuals worldwide. As both infections are strongly linked to HIV infection, they may share certain clinical manifestations, and the interaction of their treatments should be considered. However, despite their similarity, concurrent tuberculosis and cryptococcal infections have rarely been reported in West Africa. Herein, we present 3 cases of neuromeningeal cryptococcosis and lung tuberculosis coinfection collected prospectively over a year at the Department of Infectious Diseases of the Point G Teaching Hospital in Bamako. Two patients had HIV disease, and the third patient had no underlying immunosuppressive illnesses. Thus, active screening for tuberculosis and cryptococcosis, particularly in individuals with HIV, can reduce misdiagnosis and ensure appropriate coinfection management. Moreover, this may reduce mortality due to AIDS-related opportunistic infections in resource-limited settings.

The role of Mycobacterium tuberculosis acetyltransferase and protein acetylation modifications in tuberculosis

Tuberculosis (TB) is a widespread infectious disease caused by Mycobacterium tuberculosis (M. tb), which has been a significant burden for a long time. Post-translational modifications (PTMs) are essential for protein function in both eukaryotic and prokaryotic cells. This review focuses on the contribution of protein acetylation to the function of M. tb and its infected macrophages. The acetylation of M. tb proteins plays a critical role in virulence, drug resistance, regulation of metabolism, and host anti-TB immune response. Similarly, the PTMs of host proteins induced by M. tb are crucial for the development, treatment, and prevention of diseases. Host protein acetylation induced by M. tb is significant in regulating host immunity against TB, which substantially affects the disease's development. The review summarizes the functions and mechanisms of M. tb acetyltransferase in virulence and drug resistance. It also discusses the role and mechanism of M. tb in regulating host protein acetylation and immune response regulation. Furthermore, the current scenario of isoniazid usage in M. tb therapy treatment is examined. Overall, this review provides valuable information that can serve as a preliminary basis for studying pathogenic research, developing new drugs, exploring in-depth drug resistance mechanisms, and providing precise treatment for TB.

Challenges to the control of Mycobacterium bovis in livestock and wildlife populations in the South African context

Bovine tuberculosis (bTB) was first diagnosed in cattle in South Africa in 1880 and proclaimed a controlled disease in 1911. Testing of cattle for bTB is voluntary and only outbreaks of disease are reported to the National Department of Agriculture so the prevalence of the disease in cattle is largely unknown. There is a Bovine Tuberculosis Scheme which is aimed at the control of bTB in cattle but the same measures of test and slaughter, and the quarantining of the property apply to wildlife as well. bTB was first diagnosed in wildlife in a greater kudu in the Eastern Cape in 1928 and has to date been found in 24 mammalian wildlife species. The African buffalo has become a maintenance host of the disease, which is considered endemic in the Kruger National Park, the Hluhluwe-iMfolozi Park and the Madikwe Game Park. Control of bTB at the wildlife-livestock interface is difficult because of spill-over and spill-back between species. Only buffalo are required by law to be tested before translocation, but bTB has been introduced to the Madikwe Game Park probably by the translocation of other infected wildlife species. There is no national control strategy for the control of bTB in wildlife. Indirect tests have been developed to test for bTB in eight species, 6 of which can be considered endangered. More research needs to be done to develop an effective and efficient vaccine to combat the transmission of bTB within and between species. New policies need to be developed that are effective, affordable and encompassing to control the spread of bTB in South Africa.

Blood monocyte and dendritic cell profiles among people living with HIV with Mycobacterium tuberculosis co-infection

BACKGROUND

Understanding the complex interactions of the immune response mediated by Mycobacterium tuberculosis and HIV co-infection is fundamental to disease biomarker discovery, vaccine, and drug development. Using flow cytometry, we characterized the frequencies and phenotypic differences in monocytes and dendritic cell populations using peripheral blood mononuclear cells from individuals with recurrent, active pulmonary tuberculosis with and without coexisting HIV infection (CAPRISA 011, Clinicaltrials.gov, NCT02114684, 29/01/2014) and compared them to samples from HIV positive individuals and healthy controls. Additionally, we assessed the associations between the frequency of monocyte and dendritic cell subsets and time to culture conversion and cavitary disease in patients with active TB using a cox proportional hazards and logistic regression models.

RESULTS

Compared to healthy controls, the frequency of total monocytes (HLA-DR + CD14 +) was significantly higher in the TB/HIV and TB groups and the frequency of dendritic cells (HLA-DR + CD14-) was significantly higher in TB/HIV and HIV groups. We observed significant variation in the expression of CCR2, CD40, CD11b, CD86, CD163, CX3CR1 across different cell subsets in the four study groups. Increase in CCR2, CD11b and CD40 was associated with active TB infection, while decrease in CX3CR1 and increase in CD163 was associated with HIV infection. Expression of CX3CR1 (aHR 0.98, 95% CI 0.963 - 0.997, p = 0.019) on non-classical monocytes associated with longer time to TB culture conversion in the multivariable model correcting for randomization arm, age, sex, HIV status, lung cavitation, alcohol use, smoking and BMI. Higher surface expression of CD86 (aOR 1.017, 95% CI 1.001 - 1.032, p = 0.033) on intermediate monocytes associated with the presence of lung cavitation, while higher expression of transitional monocytes (aOR 0.944, 95% CI 0.892 - 0.999, p = 0.047) associated with the absence of lung cavitation in the multivariable model.

CONCLUSION

These data provide valuable insight into the heterogenous role of monocyte and dendritic cells in TB and HIV infections.

Unique Profile of Proinflammatory Cytokines in Plasma of Drug-Naïve Individuals with Advanced HIV/TB Co-Infection

HIV-1 infection is characterized by aberrant immune activation, and infection with M. tuberculosis by an unbalanced production of proinflammatory cytokines. The expression of these cytokines in HIV-1/TB coinfection is still understudied. Here, we aimed to compare the production of proinflammatory cytokines in drug-naive patients coinfected with HIV-1 and M. tuberculosis (HIV/TB) compared to patients with respective monoinfections. Plasma samples of patients with HIV/TB coinfection (n = 36), HIV-1 monoinfection (n = 36), and TB monoinfection (n = 35) and healthy donors (n = 36) were examined for the levels of eight proinflammatory cytokines. Their levels were significantly increased in all patient groups compared to healthy donors. At the same time, a drastic decrease in the plasma levels of IFN-γ, TNF-α, Il-1β, IL-15, and IL-17 was detected in patients with HIV/TB coinfection compared to patients with HIV-1 or TB monoinfections. The plasma levels of IL-17 characterized the TB severity: in HIV/TB-coinfected patients with disseminated TB, plasma levels of IL-17 were eight times lower than in patients with less severe TB forms (infiltrative TB or TB of intrathoracic lymph nodes; p < 0.0001). At the same time, HIV/TB-coinfected patients had increased plasma levels of IL-8, IL-12, and IL-18, with the levels of IL-8 correlating with mortality (p < 0.0001). Thus, on the contrary to the patients with HIV-1 or TB monoinfections, HIV/TB-coinfected patients had suppressed production of most of the proinflammatory cytokines associated with antimicrobial immune response, specifically of T-cells involved in the containment of both infections. At the same time, they demonstrated an expansion of proinflammatory cytokines known to originate from both hematopoietic and nonhematopoietic cells, and manifest tissue inflammation. In HIV-1/TB coinfection, this leads to the disruption of granuloma formation, contributing to bacterial dissemination and enhancing morbidity and mortality.

Structural basis of DNA binding by the WhiB-like transcription factor WhiB3 in Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) WhiB3 is an iron-sulfur cluster-containing transcription factor belonging to a subclass of the WhiB-Like (Wbl) family that is widely distributed in the phylum Actinobacteria. WhiB3 plays a crucial role in the survival and pathogenesis of Mtb. It binds to the conserved region 4 of the principal sigma factor (σA4) in the RNA polymerase holoenzyme to regulate gene expression like other known Wbl proteins in Mtb. However, the structural basis of how WhiB3 coordinates with σA4 to bind DNA and regulate transcription is unclear. Here we determined crystal structures of the WhiB3:σA4 complex without and with DNA at 1.5 Å and 2.45 Å, respectively, to elucidate how WhiB3 interacts with DNA to regulate gene expression. These structures reveal that the WhiB3:σA4 complex shares a molecular interface similar to other structurally characterized Wbl proteins and also possesses a subclass-specific Arg-rich DNA-binding motif. We demonstrate that this newly defined Arg-rich motif is required for WhiB3 binding to DNA in vitro and transcriptional regulation in Mycobacterium smegmatis. Together, our study provides empirical evidence of how WhiB3 regulates gene expression in Mtb by partnering with σA4 and engaging with DNA via the subclass-specific structural motif, distinct from the modes of DNA interaction by WhiB1 and WhiB7.

Prevalence and Predictors of Pulmonary Tuberculosis among Prison Inmates in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Introduction

Prisoners in Sub-Saharan Africa (SSA) are at a high risk of tuberculosis (TB) infection due to overcrowding and poor ventilation. Consequently, TB is a leading cause of morbidity and mortality in prison, and many inmates face a number of barriers to TB control and had limited information in the region. Thus, the aim of this systematic review and meta-analysis was to estimate the overall pooled prevalence of pulmonary TB and predictors among prison inmates in SSA.

Methods

From 2006 to 2019, a systematic review and meta-analysis was conducted using various databases, including PubMed, Embase, Web of Science, and Scopus. The data were extracted in Microsoft Excel using a standardized data extraction format, and the analysis was carried out with STATA version 14. To detect heterogeneity across studies, the I² and the Cochrane Q test statistics were computed. To determine the overall prevalence of TB and predictors among prison populations, a random effect meta-analysis model was used.

Results

Of the 3,479 retrieved articles, 37studies comprising 72,844 inmates met the inclusion criteria. The pooled prevalence of pulmonary TB among prison inmates in SSA was 7.74% (95% CI: 6.46-8.47). In the subgroup analysis, the highest prevalence was found in the Democratic Republic Congo (DRC) (19.72%) followed by Zambia (11.68%) and then Ethiopia (9.22%). TB/HIV coinfection (OR 4.99 (95% CI: 2.60-9.58)), Body mass index (BMI < 18.5) (OR 3.62 (95% CI: 2.65-6.49)), incarceration (OR 4.52 (95% CI: 2.31-5.68)), and previous TB exposure (OR 2.43 (95% CI: 1.61-3.56)) had higher odds of pulmonary TB among inmates.

Conclusion

The prevalence of pulmonary TB among SSA prison inmates was found to be high as compared to total population. TB/HIV coinfection, BMI, incarceration duration, and TB exposure were all predictors with pulmonary tuberculosis in prison inmates. As a result, emphasizing early screening for prisoners at risk of pulmonary TB is an important point to achieving global TB commitments in resource-limited settings.

Quantitative Assessment of a Dual Epidemic Caused by Tuberculosis and HIV in the Philippines

Tuberculosis (TB) and human immunodeficiency virus (HIV) are the two major public health emergencies in the Philippines. The country is ranked fourth worldwide in TB incidence cases despite national efforts and initiatives to mitigate the disease. Concurrently, the Philippines has the fastest-growing HIV epidemic in Asia and the Pacific region. The TB-HIV dual epidemic forms a lethal combination enhancing each other's progress, driving the deterioration of immune responses. In order to understand and describe the transmission dynamics and epidemiological patterns of the co-infection, a compartmental model for TB-HIV is developed. A class of people living with HIV (PLHIV) who did not know their HIV status is incorporated into the model. These unaware PLHIV who do not seek medical treatment are potential sources of new HIV infections that could significantly influence the disease transmission dynamics. Sensitivity analysis using the partial rank correlation coefficient is performed to assess model parameters that are influential to the output of interests. The model is calibrated using available Philippine data on TB, HIV, and TB-HIV. Parameters that are identified include TB and HIV transmission rates, progression rates from exposed to active TB, and from TB-latent with HIV to active infectious TB with HIV in the AIDS stage. Uncertainty analysis is performed to identify the degree of accuracy of the estimates. Simulations predict an alarming increase of 180% and 194% in new HIV and TB-HIV infections in 2025, respectively, relative to 2019 data. These projections underscore an ongoing health crisis in the Philippines that calls for a combined and collective effort by the government and the public to take action against the lethal combination of TB and HIV.

Survival and predictors of mortality after completion of TB treatment among people living with HIV: a 5-year analytical cohort

BACKGROUND

After completion of TB treatment patients may remain at risk of co-morbidity and mortality. We determined the survival and predictors of all-cause mortality after completing TB treatment among ART-experienced patients.

METHODS

This was a retrospective cohort analysis of all ART experienced patients who completed TB treatment at a specialist HIV clinic in Uganda, between 2009 and 2014. The patients were followed for five years after TB treatment. We determined the cumulative probability of death, and predictors of mortality using Kaplan-Meier methods and Cox proportional hazard models, respectively.

RESULTS

A total 1,287 patients completed TB treatment between 2009 and 2014, of which 1,111 were included in the analysis. At TB treatment completion, the median age was 36 years (IQR: 31-42), 563 (50.7%) were males, and median CD4 cell count was 235 cells/mL (IQR: 139-366). The person-time at risk was 4410.60 person-years. The all-cause mortality rate was 15.42 (95% CI: 12.14-19.59) per 1000 person-years. The probability of death at five years was 6.9% (95%CI: 5.5- 8.8). In the multivariable analysis, CD4 count < 200 cells/mL was a predictor of all-cause mortality (aHR = 1.81, 95%CI:1.06-3.11, p = 0.03) alongside history of retreatment (aHR = 2.12, 95%CI: 1.16-3.85, p = 0.01).

CONCLUSION

Survival post TB treatment in ART experienced PLHIV is reasonably good. Most deaths occur within two years after TB treatment completion. Patients with a low CD4 count and those with a history of retreatment have an increased risk of mortality which underscores the need for TB prophylaxis, detailed assessment, and close monitoring after completion of TB treatment.

Mycobacterium tuberculosis Infection: Control and Treatment

Tuberculosis (TB) is the second leading infectious killer after COVID-19, causing 10 million new cases and claiming the lives of more than 1 [...].

A Review of the Development of Multitarget Molecules against HIV-TB Coinfection Pathogens

The human immunodeficiency virus (HIV) produces the pathologic basis of acquired immunodeficiency syndrome (AIDS). An increase in the viral load in the body leads to a decline in the number of T lymphocytes, compromising the patient's immune system. Some opportunistic diseases may result, such as tuberculosis (TB), which is the most common in seropositive patients. Long-term treatment is required for HIV-TB coinfection, and cocktails of drugs for both diseases are used concomitantly. The most challenging aspects of treatment are the occurrence of drug interactions, overlapping toxicity, no adherence to treatment and cases of resistance. Recent approaches have involved using molecules that can act synergistically on two or more distinct targets. The development of multitarget molecules could overcome the disadvantages of the therapies used to treat HIV-TB coinfection. This report is the first review on using molecules with activities against HIV and Mycobacterium tuberculosis (MTB) for molecular hybridization and multitarget strategies. Here, we discuss the importance and development of multiple targets as a means of improving adherence to therapy in cases of the coexistence of these pathologies. In this context, several studies on the development of structural entities to treat HIV-TB simultaneously are discussed.

Progression of blood-borne viruses through bloodstream: A comparative mathematical study

BACKGROUND AND OBJECTIVES

Blood-borne pathogens are contagious microorganisms that can cause life-threatening illnesses, and are found in human blood. It is crucial to examine how these viruses spread through blood flow in the blood vessel. Keeping that in view, this study aims to determine how blood viscosity, and diameter of the viruses can affect the virus transmission through the blood flow in the blood vessel. A comparative study of bloodborne viruses (BBVs) such as HIV, Hepatitis B, and C, has been addressed in the present model. A couple stress fluid model is used to represent blood as a carrying medium for virus transmission. The Basset-Boussinesq-Oseen equation is taken into account for the simulation of virus transmission.

METHODS

An analytical approach to derive the exact solutions under the assumption of long wavelength and low Reynolds number approximations is employed. For the computation of the results, a segment (wavelength) of blood vessels about 120 mm with wave velocities in the range of 49 - 190 mm/sec are considered, where the diameter of BBVs ranges from 40-120 nm. The viscosity of the blood varies from 3.5-5.5 × 10^-3Ns/m² which affect the virion motion having a density range 1.03 - 1. 25 g/m³.

RESULTS

It shows that the Hepatitis B virus is more harmful than other blood-borne viruses considered in the analysis. Patients with high blood pressure are highly susceptible for transmission of BBVs.

CONCLUSIONS

The present fluid dynamics approach for virus spread through blood flow can be helpful in understanding the dynamics of virus propagation inside the human circulatory system.

Clinico-demographic and survival profile of people living with HIV on antiretroviral treatment

OBJECTIVE

To assess the demographic, clinical, and survival profile of people living with HIV.

METHODS

A retrospective cohort study was conducted among patients enrolled at a single antiretroviral therapy center in North Karnataka. A total of 11,099 were recruited from April 2007 to January 2020, out of which 3,676 were excluded and the final 7,423 entries were subjected to analysis. The outcome of interest was the time to death in months of people living with HIV on antiretroviral therapy (ART). The clinical and demographic characteristics were examined as potential risk factors for survival analysis. To investigate the factors that influence the mortality of patients using ART, univariate and multivariate Cox regression were performed. Hazard ratio (HR), 95% confidence interval (CI), and p-values were presented to show the significance. The log-rank test was used to determine the significance of the Kaplan-Meier survival curve.

RESULTS

Out of 7,423 HIV-positive people, majority were female (51.4%), heterosexual typology (89.2%), and in the age group 31-45 years (45.5%). The risk of death in male patients was 1.24 times higher (95% CI: 1.14-1.35) than female patients. Patients with age >45 were 1.67 times more likely to die than patients ≤30 (95% CI: 1.50-1.91). In the multivariable analysis, the hazards of mortality increased by 3.11 times (95% CI: 2.09-2.79) in patients with baseline CD4 count ≤50 as compared to those who had baseline CD4 count >200. The risk of death in patients who were diagnosed with TB was 1.30 times more (95% CI: 1.19-1.42) than in those who did not have TB. The survival probabilities at 3 and 90 months were more in female patients (93%, 70%) compared with male patients (89, 54%), respectively.

CONCLUSION

This study proved that age, sex, baseline CD4 count, and tuberculosis (TB) status act as risk factors for mortality among people with HIV. Prevention strategies, control measures, and program planning should be done based on the sociodemographic determinants of mortality.

Tuberculosis: Pathogenesis, Current Treatment Regimens and New Drug Targets

Mycobacterium tuberculosis (M. tb), the causative agent of TB, is a recalcitrant pathogen that is rife around the world, latently infecting approximately a quarter of the worldwide population. The asymptomatic status of the dormant bacteria escalates to the transmissible, active form when the host's immune system becomes debilitated. The current front-line treatment regimen for drug-sensitive (DS) M. tb strains is a 6-month protocol involving four different drugs that requires stringent adherence to avoid relapse and resistance. Poverty, difficulty to access proper treatment, and lack of patient compliance contributed to the emergence of more sinister drug-resistant (DR) strains, which demand a longer duration of treatment with more toxic and more expensive drugs compared to the first-line regimen. Only three new drugs, bedaquiline (BDQ) and the two nitroimidazole derivatives delamanid (DLM) and pretomanid (PMD) were approved in the last decade for treatment of TB-the first anti-TB drugs with novel mode of actions to be introduced to the market in more than 50 years-reflecting the attrition rates in the development and approval of new anti-TB drugs. Herein, we will discuss the M. tb pathogenesis, current treatment protocols and challenges to the TB control efforts. This review also aims to highlight several small molecules that have recently been identified as promising preclinical and clinical anti-TB drug candidates that inhibit new protein targets in M. tb.

The interactions of SARS-CoV-2 with cocirculating pathogens: Epidemiological implications and current knowledge gaps

Despite the availability of effective vaccines, the persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suggests that cocirculation with other pathogens and resulting multiepidemics (of, for example, COVID-19 and influenza) may become increasingly frequent. To better forecast and control the risk of such multiepidemics, it is essential to elucidate the potential interactions of SARS-CoV-2 with other pathogens; these interactions, however, remain poorly defined. Here, we aimed to review the current body of evidence about SARS-CoV-2 interactions. Our review is structured in four parts. To study pathogen interactions in a systematic and comprehensive way, we first developed a general framework to capture their major components: sign (either negative for antagonistic interactions or positive for synergistic interactions), strength (i.e., magnitude of the interaction), symmetry (describing whether the interaction depends on the order of infection of interacting pathogens), duration (describing whether the interaction is short-lived or long-lived), and mechanism (e.g., whether interaction modifies susceptibility to infection, transmissibility of infection, or severity of disease). Second, we reviewed the experimental evidence from animal models about SARS-CoV-2 interactions. Of the 14 studies identified, 11 focused on the outcomes of coinfection with nonattenuated influenza A viruses (IAVs), and 3 with other pathogens. The 11 studies on IAV used different designs and animal models (ferrets, hamsters, and mice) but generally demonstrated that coinfection increased disease severity compared with either monoinfection. By contrast, the effect of coinfection on the viral load of either virus was variable and inconsistent across studies. Third, we reviewed the epidemiological evidence about SARS-CoV-2 interactions in human populations. Although numerous studies were identified, only a few were specifically designed to infer interaction, and many were prone to multiple biases, including confounding. Nevertheless, their results suggested that influenza and pneumococcal conjugate vaccinations were associated with a reduced risk of SARS-CoV-2 infection. Finally, fourth, we formulated simple transmission models of SARS-CoV-2 cocirculation with an epidemic viral pathogen or an endemic bacterial pathogen, showing how they can naturally incorporate the proposed framework. More generally, we argue that such models, when designed with an integrative and multidisciplinary perspective, will be invaluable tools to resolve the substantial uncertainties that remain about SARS-CoV-2 interactions.

Targeting mycobacterial membranes and membrane proteins: Progress and limitations

Among the various bacterial infections, tuberculosis continues to hold center stage. Its causative agent, Mycobacterium tuberculosis, possesses robust defense mechanisms against most front-line antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. It is now well-established that bacteria change their membrane composition to optimize their environment to survive and elude drug action. Thus targeting membrane or membrane components is a promising avenue for exploiting the chemical space focussed on developing novel membrane-centric anti-bacterial small molecules. These approaches are more effective, non-toxic, and can attenuate resistance phenotype. We present the relevance of targeting the mycobacterial membrane as a practical therapeutic approach. The review highlights the direct and indirect targeting of membrane structure and function. Direct membrane targeting agents cause perturbation in the membrane potential and can cause leakage of the cytoplasmic contents. In contrast, indirect membrane targeting agents disrupt the function of membrane-associated proteins involved in cell wall biosynthesis or energy production. We discuss the chronological chemical improvements in various scaffolds targeting specific membrane-associated protein targets, their clinical evaluation, and up-to-date account of their ''mechanisms of action, potency, selectivity'' and limitations. The sources of anti-TB drugs/inhibitors discussed in this work have emerged from target-based identification, cell-based phenotypic screening, drug repurposing, and natural products. We believe this review will inspire the exploration of uncharted chemical space for informing the development of new scaffolds that can inhibit novel mycobacterial membrane targets.

Predictors of death among TB/HIV co-infected patients on tuberculosis treatment in Sichuan, China: A retrospective cohort study

Mycobacterium tuberculosis is the most common opportunistic infection among patients with human immunodeficiency virus (HIV) infection, and it is also the leading cause of death, causing approximately one-third of acquired immune deficiency syndrome deaths worldwide. China is on the World Health Organization's global list of 30 high-tuberculosis (TB) burden countries. The objective of this study was to evaluate the mortality rate, survival probabilities, and factors associated with death among patients with TB/HIV co-infection undergoing TB treatment in Sichuan, China. A retrospective cohort study was conducted using the Chinese National TB Surveillance System data of TB/HIV co-infected patients enrolled in TB treatment from January 2020 to December 2020. We calculated the mortality rate and survival probabilities using the Kaplan-Meier estimator, and a Cox proportional hazard model was conducted to identify independent risk factors for TB/HIV co-infection mortality. Hazard ratios and their respective 95% confidence intervals were also reported in this study. Of 828 TB/HIV co-infected patients, 44 (5.31%) died during TB treatment, and the crude mortality rate was 7.76 per 1000 person-months. More than half of the deaths (n = 23) occurred in the first 3 months of TB treatment. Overall survival probabilities were 97.20%, 95.16%, and 91.75% at 3rd, 6th, and 12th month respectively. The independent risk factors for mortality among TB/HIV co-infected patients were having extra-pulmonary TB and pulmonary TB co-infection, history of antiretroviral therapy interruption, and baseline cluster of differentiation 4 T-lymphocyte counts <200 cells/μL at the time of HIV diagnosis. Antiretroviral therapy is important for the survival of TB/HIV co-infected patients, and it is recommended to help prolong life by restoring immune function and preventing extra-pulmonary TB.

Coupling between infectious diseases leads to synchronization of their dynamics

Interactions between different diseases may change their dynamics. Thus, these interactions represent a source of uncertainty in the modeling of empirical data when the symptoms of both infections are hard to distinguish. We recall previously proposed models of interacting infections, generalizing them to non-symmetric scenarios, showing that both cooperative and competitive interactions lead to synchronization of the maximum fraction of infected individuals in their dynamics. We exemplify this framework with a model coupling the dynamics of COVID-19 and seasonal influenza, simulating cooperation, competition, and asymmetric interactions. We find that the coupling synchronizes both infections, with a stronger influence on the dynamics of influenza.

The COVID-19, tuberculosis and HIV/AIDS: Ménage à Trois

In December 2019, a novel pneumonic condition, Coronavirus disease 2019 (COVID- 19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), broke out in China and spread globally. The presentation of COVID-19 is more severe in persons with underlying medical conditions such as Tuberculosis (TB), Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) and other pneumonic conditions. All three diseases are of global concern and can significantly affect the lungs with characteristic cytokine storm, immunosuppression, and respiratory failure. Co-infections of SARS-CoV-2 with HIV and Mycobacterium tuberculosis (Mtb) have been reported, which may influence their pathogenesis and disease progression. Pulmonary TB and HIV/AIDS patients could be more susceptible to SARS-CoV-2 infection leading to lethal synergy and disease severity. Therefore, the biological and epidemiological interactions of COVID-19, HIV/AIDS, and TB need to be understood holistically. While data is needed to predict the impact of the COVID-19 pandemic on these existing diseases, it is necessary to review the implications of the evolving COVID-19 management on HIV/AIDS and TB control, including therapy and funding. Also, the impact of long COVID on patients, who may have this co-infection. Thus, this review highlights the implications of COVID-19, HIV/AIDS, and TB co-infection compares disease mechanisms, addresses growing concerns, and suggests a direction for improved diagnosis and general management.

A Structural View at Vaccine Development against M. tuberculosis

Tuberculosis (TB) is still the leading global cause of death from an infectious bacterial agent. Limiting tuberculosis epidemic spread is therefore an urgent global public health priority. As stated by the WHO, to stop the spread of the disease we need a new vaccine, with better coverage than the current Mycobacterium bovis BCG vaccine. This vaccine was first used in 1921 and, since then, there are still no new licensed tuberculosis vaccines. However, there is extremely active research in the field, with a steep acceleration in the past decades, due to the advance of technologies and more rational vaccine design strategies. This review aims to gather latest updates in vaccine development in the various clinical phases and to underline the contribution of Structural Vaccinology (SV) to the development of safer and effective antigens. In particular, SV and the development of vaccine adjuvants is making the use of subunit vaccines, which are the safest albeit the less antigenic ones, an achievable goal. Indeed, subunit vaccines overcome safety concerns but need to be rationally re-engineered to enhance their immunostimulating effects. The larger availability of antigen structural information as well as a better understanding of the complex host immune response to TB infection is a strong premise for a further acceleration of TB vaccine development.

Booster Vaccination Against SARS-CoV-2 Induces Potent Immune Responses in People With Human Immunodeficiency Virus

BACKGROUND

People with human immunodeficiency virus (HIV) on antiretroviral therapy (ART) with good CD4 T-cell counts make effective immune responses following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are few data on longer term responses and the impact of a booster dose.

METHODS

Adults with HIV were enrolled into a single arm open label study. Two doses of ChAdOx1 nCoV-19 were followed 12 months later by a third heterologous vaccine dose. Participants had undetectable viraemia on ART and CD4 counts >350 cells/µL. Immune responses to the ancestral strain and variants of concern were measured by anti-spike immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), MesoScale Discovery (MSD) anti-spike platform, ACE-2 inhibition, activation induced marker (AIM) assay, and T-cell proliferation.

FINDINGS

In total, 54 participants received 2 doses of ChAdOx1 nCoV-19. 43 received a third dose (42 with BNT162b2; 1 with mRNA-1273) 1 year after the first dose. After the third dose, total anti-SARS-CoV-2 spike IgG titers (MSD), ACE-2 inhibition, and IgG ELISA results were significantly higher compared to Day 182 titers (P < .0001 for all 3). SARS-CoV-2 specific CD4+ T-cell responses measured by AIM against SARS-CoV-2 S1 and S2 peptide pools were significantly increased after a third vaccine compared to 6 months after a first dose, with significant increases in proliferative CD4+ and CD8+ T-cell responses to SARS-CoV-2 S1 and S2 after boosting. Responses to Alpha, Beta, Gamma, and Delta variants were boosted, although to a lesser extent for Omicron.

CONCLUSIONS

In PWH receiving a third vaccine dose, there were significant increases in B- and T-cell immunity, including to known variants of concern (VOCs).

The Environmental and Socioeconomic Effects and Prediction of Patients With Tuberculosis in Different Age Groups in Southwest China: A Population-Based Study

BACKGROUND

While the End Tuberculosis (TB) Strategy has been implemented worldwide, the cause of the TB epidemic is multifactorial and not fully understood.

OBJECTIVE

This study aims to investigate the risk factors of TB and incorporate these factors to forecast the incidence of TB infection across different age groups in Sichuan, China.

METHODS

Correlation and linear regression analyses were conducted to assess the relationships between TB cases and ecological factors, including environmental, economic, and social factors, in Sichuan Province from 2006 to 2017. The transfer function-noise model was used to forecast trends, considering both time and multifactor effects.

RESULTS

From 2006 to 2017, Sichuan Province had a reported cumulative incidence rate of 1321.08 cases per 100,000 individuals in male patients and 583.04 cases per 100,000 individuals in female patients. There were significant sex differences in the distribution of cases among age groups (trend χ²₂₅=12,544.4; P<.001). Ganzi Tibetan Autonomous Prefecture had the highest incidence rates of TB in both male and female patients in Sichuan. Correlation and regression analyses showed that the total illiteracy rate and average pressure at each measuring station (for individuals aged 15-24 years) were risk factors for TB. The protective factors were as follows: the number of families with the minimum living standard guarantee in urban areas, the average wind speed, the number of discharged patients with invasive TB, the number of people with the minimum living standard guarantee in rural areas, the total health expenditure as a percentage of regional gross domestic product, and being a single male individual (for those aged 0-14 years); the number of hospitals and number of health workers in infectious disease hospitals (for individuals aged 25-64 years); and the amount of daily morning and evening exercise, the number of people with the urban minimum living standard guarantee, and being married (for female individuals aged ≥65 years). The transfer function-noise model indicated that the incidence of TB in male patients aged 0-14 and 15-24 years will continue to increase, and the incidence of TB in female patients aged 0-14 and ≥65 years will continue to increase rapidly in Sichuan by 2035.

CONCLUSIONS

The End TB Strategy in Sichuan should consider environmental, educational, medical, social, personal, and other conditions, and further substantial efforts are needed especially for male patients aged 0-24 years, female patients aged 0-14 years, and female patients older than 64 years.

Sleep quality and its associated factors among patients with tuberculosis: A cross-sectional study

Background

Tuberculosis (TB) patients commonly suffer from sleep issues owing to various adverse drug reactions (ADRs), disease symptoms, and the contagious nature of their disease. These sleep issues negatively affect the treatment outcome and quality of life. However, the prevalence of sleep disturbance and its associated factors among TB patients have rarely been reported.

Methods

A total of 497 inpatients with TB from three hospitals in China were enrolled in this cross-sectional study to investigate their sleep quality using the Pittsburgh sleep quality index (PSQI). Clinical data, including demographic information, TB-related stigma, perceived stress, and nutrition- and immunity-related indicators, were also collected to explore the factors associated with sleep disturbance among the recruited patients.

Results

Approximately 70% of the recruited patients reported a sleep disturbance to varying degrees, presenting poorer global and subjective sleep qualities, longer sleep latency, shorter sleep duration, lower sleep efficiency, more frequent sleep disturbances, greater use of sleeping medication, and more severe daytime dysfunction. Furthermore, the body mass index (BMI), hemoglobin levels, albumin levels, and T lymphocyte count of the patients in the poor sleep quality group were significantly lower than those in the good sleep quality group (p < 0.05). Increasing age, higher income, drug resistance, higher stigma or stress perception, lower albumin levels, and lower CD4 levels were significantly associated with sleep disturbance among TB patients (p < 0.05).

Conclusion

Three-quarters of the participants were found to suffer from a probable sleep disturbance. And sleep problems are linked to biological traits that interact with psychological, cultural, and social factors in complex ways. It is therefore important to pay attention to the sleep quality of TB patients, especially those with the identified risk factors. Besides, taking care of these risk factors may prove to be an effective sleep management strategy.

The role of serum circulating microbial toxins in severity and cytokine storm of COVID positive patients

The emergence of Coronavirus disease 2019 (Covid-19) is a global problem nowadays, causing health difficulty with increasing mortality rates, which doesn't have a verified treatment. SARS-CoV-2 infection has various pathological and epidemiological characteristics, one of them is increased amounts of cytokine production, which in order activate an abnormal unrestricted response called "cytokine storm". This event contributes to severe acute respiratory distress syndrome (ARDS), which results in respiratory failure and pneumonia and is the great cause of death associated with Covid-19. Endotoxemia and the release of bacterial lipopolysaccharides (endotoxins) from the lumen into the bloodstream enhance proinflammatory cytokines. SARS-CoV-2 can straightly interplay with endotoxins via its S protein, leading to the extremely elevating release of cytokines and consequently increase the harshness of Covid-19. In this review, we will discuss the possible role of viral-bacterial interaction that occurs through the transfer of bacterial products such as lipopolysaccharide (LPS) from the intestine into the bloodstream, exacerbating the severity of Covid-19 and cytokine storms.

Tuberculosis: The success tale of less explored dormant Mycobacterium tuberculosis

Mycobacterium tuberculosis (M.tb) is an intracellular pathogen that predominantly affects the alveolar macrophages in the respiratory tract. Upon infection, the activation of TLR2 and TLR4- mediated signaling pathways leads to lysosomal degradation of the bacteria. However, bacterium counteracts the host immune cells and utilizes them as a cellular niche for its survival. One distinctive mechanism of M.tb to limit the host stress responses such as hypoxia and nutrient starvation is induction of dormancy. As the environmental conditions become favorable, the bacteria resuscitate, resulting in a relapse of clinical symptoms. Different bacterial proteins play a critical role in maintaining the state of dormancy and resuscitation, namely, DevR (DosS), Hrp1, DATIN and RpfA-D, RipA, etc., respectively. Existing knowledge regarding the key proteins associated with dormancy and resuscitation can be employed to develop novel therapies. In this review we aim to highlight the current knowledge of bacterial progression from dormancy to resuscitation and the gaps in understanding the transition from dormant to active state. We have also focused on elucidating a few therapeutic strategies employed to prevent M.tb resuscitation.

Treatment outcome and its associated factors among HIV-MTB co-infected patients in Sichuan, China: A retrospective study

Human immunodeficiency virus (HIV)-Mycobacterium tuberculosis (MTB) co-infection has become a pressing global public health problem. Although tuberculosis (TB) is both treatable and curable, it has been exacerbated by the HIV/acquired immune deficiency syndrome (AIDS) epidemic. HIV-MTB co-infected patients have a variety of disease-specific, and treatment-related factors that can adversely affect their treatment outcomes. This study was conducted to assess the outcomes of TB treatment and its associated factors among HIV-MTB co-infected patients in Sichuan, Southwest China. A retrospective study was performed on HIV-MTB co-infected patients who were diagnosed and registered in TB designated hospitals in Sichuan from January 1, 2016, to December 31, 2020. Data were collected from patients' electronic medical records regarding their demographic, clinical, and social support information, and categorical data, such as sex, were reported using numbers and percentages. χ2 and t-tests were conducted to compare groups in relation to different levels of medical institutions. A binary logistic regression model was used to identify the factors associated with unsuccessful TB treatment outcomes. For logistic regression analysis performed using an α of 0.05, odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated for various risk factors. A total of 3677 registered HIV-MTB co-infected patients were enrolled. After adjusting for other variables, male, advanced age, receiving TB treatment at the municipal medical institution, being diagnosed with external pulmonary TB, referral or tracing, being sputum smear positive, not initiating antiretroviral therapy (ART) and not using fixed-dose combinations were the main risk factors for treatment failure of HIV-MTB co-infected patients in Sichuan province. Sex, age, hospital level, patient source, other diagnostic factors (e.g., sputum smear results, anatomical site of TB), and factors of therapeutic schemes (e.g., antiretroviral therapy, fixed-dose combinations) may serve as risk factors to estimate the likely treatment outcome of HIV-TB co-infection.

Tuberculosis in pregnancy

Due to COVID-19 pandemic, the latest progress of the End Tuberculosis (TB) Strategy was far from optimal and services for TB needs to be quickly restored. Pregnancy is a unique opportunity to screen and manage TB, and it is an essential step in TB eradication. Early diagnosis and treatment for active disease can reduce maternal and neonatal morbidities and mortality. The more widespread utilization of newer rapid molecular assays with drug-susceptibility testing has significantly shortened the diagnostic process for active TB disease. First-line anti-TB drugs are proven to be safe in pregnancy. Management of latent TB infection (LTBI) during pregnancy is controversial, but puerperium is a period of increased susceptibility to progress to active disease. Extrapulmonary TB (EPTB), multidrug-resistant TB (MDR-TB) and HIV co-infection remain significant issues surrounding TB management during pregnancy and often require input from a multidisciplinary team including TB experts.

Mycobacterium tuberculosis Dormancy: How to Fight a Hidden Danger

Both latent and active TB infections are caused by a heterogeneous population of mycobacteria, which includes actively replicating and dormant bacilli in different proportions. Dormancy substantially affects M. tuberculosis drug tolerance and TB clinical management due to a significant decrease in the metabolic activity of bacilli, which leads to the complexity of both the diagnosis and the eradication of bacilli. Most diagnostic approaches to latent infection deal with a subpopulation of active M. tuberculosis, underestimating the contribution of dormant bacilli and leading to limited success in the fight against latent TB. Moreover, active TB appears not only as a primary form of infection but can also develop from latent TB, when resuscitation from dormancy is followed by bacterial multiplication, leading to disease progression. To win against latent infection, the identification of the Achilles' heel of dormant M. tuberculosis is urgently needed. Regulatory mechanisms and metabolic adaptation to growth arrest should be studied using in vitro and in vivo models that adequately imitate latent TB infection in macroorganisms. Understanding the mechanisms underlying M. tuberculosis dormancy and resuscitation may provide clues to help control latent infection, reduce disease severity in patients, and prevent pathogen transmission in the population.

Advancing mRNA technologies for therapies and vaccines: An African context

Synthetic mRNA technologies represent a versatile platform that can be used to develop advanced drug products. The remarkable speed with which vaccine development programs designed and manufactured safe and effective COVID-19 vaccines has rekindled interest in mRNA technology, particularly for future pandemic preparedness. Although recent R&D has focused largely on advancing mRNA vaccines and large-scale manufacturing capabilities, the technology has been used to develop various immunotherapies, gene editing strategies, and protein replacement therapies. Within the mRNA technologies toolbox lie several platforms, design principles, and components that can be adapted to modulate immunogenicity, stability, in situ expression, and delivery. For example, incorporating modified nucleotides into conventional mRNA transcripts can reduce innate immune responses and improve in situ translation. Alternatively, self-amplifying RNA may enhance vaccine-mediated immunity by increasing antigen expression. This review will highlight recent advances in the field of synthetic mRNA therapies and vaccines, and discuss the ongoing global efforts aimed at reducing vaccine inequity by establishing mRNA manufacturing capacity within Africa and other low- and middle-income countries.

Interactions between seasonal temperature variation and temporal synchrony drive increased arbovirus co-infection incidence

Though instances of arthropod-borne (arbo)virus co-infection have been documented clinically, the overall incidence of arbovirus co-infection and its drivers are not well understood. Now that dengue, Zika and chikungunya viruses are all in circulation across tropical and subtropical regions of the Americas, it is important to understand the environmental and biological conditions that make co-infections more likely to occur. To understand this, we developed a mathematical model of co-circulation of two arboviruses, with transmission parameters approximating dengue, Zika and/or chikungunya viruses, and co-infection possible in both humans and mosquitoes. We examined the influence of seasonal timing of arbovirus co-circulation on the extent of co-infection. By undertaking a sensitivity analysis of this model, we examined how biological factors interact with seasonality to determine arbovirus co-infection transmission and prevalence. We found that temporal synchrony of the co-infecting viruses and average temperature were the most influential drivers of co-infection incidence. Our model highlights the synergistic effect of co-transmission from mosquitoes, which leads to more than double the number of co-infections than would be expected in a scenario without co-transmission. Our results suggest that appreciable numbers of co-infections are unlikely to occur except in tropical climates when the viruses co-occur in time and space.

Fluoroquinolone heteroresistance, antimicrobial tolerance, and lethality enhancement

With tuberculosis, the emergence of fluoroquinolone resistance erodes the ability of treatment to interrupt the progression of MDR-TB to XDR-TB. One way to reduce the emergence of resistance is to identify heteroresistant infections in which subpopulations of resistant mutants are likely to expand and make the infections fully resistant: treatment modification can be instituted to suppress mutant enrichment. Rapid DNA-based detection methods exploit the finding that fluoroquinolone-resistant substitutions occur largely in a few codons of DNA gyrase. A second approach for restricting the emergence of resistance involves understanding fluoroquinolone lethality through studies of antimicrobial tolerance, a condition in which bacteria fail to be killed even though their growth is blocked by lethal agents. Studies with Escherichia coli guide work with Mycobacterium tuberculosis. Lethal action, which is mechanistically distinct from blocking growth, is associated with a surge in respiration and reactive oxygen species (ROS). Mutations in carbohydrate metabolism that attenuate ROS accumulation create pan-tolerance to antimicrobials, disinfectants, and environmental stressors. These observations indicate the existence of a general death pathway with respect to stressors. M. tuberculosis displays a variation on the death pathway idea, as stress-induced ROS is generated by NADH-mediated reductive stress rather than by respiration. A third approach, which emerges from lethality studies, uses a small molecule, N-acetyl cysteine, to artificially increase respiration and additional ROS accumulation. That enhances moxifloxacin lethality with M. tuberculosis in culture, during infection of cultured macrophages, and with infection of mice. Addition of ROS stimulators to fluoroquinolone treatment of tuberculosis constitutes a new direction for suppressing the transition of MDR-TB to XDR-TB.

Tuberculosis among Ambulatory People Living with HIV in Guangxi Province, China: A Longitudinal Study

BACKGROUND

This study aims to determine the prevalence of TB among ambulatory people living with HIV in Guangxi Province, which experienced the biggest HIV epidemic in China.

METHODS

We undertook a longitudinal study in five HIV/AIDS designated hospitals randomly selected from Guangxi Province; all newly diagnosed HIV/AIDS outpatients from 2019 to 2021 were screened for TB and interviewed with a questionnaire.

RESULTS

A total of 4539 HIV/AIDS outpatients were enrolled, with 2886 (63.6%) men and 1653 (26.4%) women. The prevalence of TB/HIV coinfection was 0.8%, with a clear downward trend from 1.3% in 2019 to 0.4% in 2021 (p = 0.0011). The prevalence of LTBI was 24.3%, with no significant differences from 2019 to 2021. The percentages of AIDS, comorbidity, nine symptoms and abnormal chest X-ray of TB were higher than those of the other PLWH.

CONCLUSION

The prevalence of TB among ambulatory people with HIV in Guangxi Province was 14 times higher than the general population, and the annual declined TB prevalence indicated the effectiveness of TB and HIV control and prevention over recent years. The findings proved that symptom screening was insufficient for TB diagnosis and highlighted the importance of systematic TB screening at every visit to a health facility.

An intranasal stringent response vaccine targeting dendritic cells as a novel adjunctive therapy against tuberculosis

Lengthy tuberculosis (TB) treatment is required to overcome the ability of a subpopulation of persistent Mycobacterium tuberculosis (Mtb) to remain in a non-replicating, antibiotic-tolerant state characterized by metabolic remodeling, including induction of the RelMtb-mediated stringent response. We developed a novel therapeutic DNA vaccine containing a fusion of the relMtb gene with the gene encoding the immature dendritic cell-targeting chemokine, MIP-3α/CCL20. To augment mucosal immune responses, intranasal delivery was also evaluated. We found that intramuscular delivery of the MIP-3α/relMtb (fusion) vaccine or intranasal delivery of the relMtb (non-fusion) vaccine potentiate isoniazid activity more than intramuscular delivery of the DNA vaccine expressing relMtb alone in a chronic TB mouse model (absolute reduction of Mtb burden: 0.63 log10 and 0.5 log10 colony-forming units, respectively; P=0.0002 and P=0.0052), inducing pronounced Mtb-protective immune signatures. The combined approach involving intranasal delivery of the DNA MIP-3α/relMtb fusion vaccine demonstrated the greatest mycobactericidal activity together with isoniazid when compared to each approach alone (absolute reduction of Mtb burden: 1.13 log10, when compared to the intramuscular vaccine targeting relMtb alone; P<0.0001), as well as robust systemic and local Th1 and Th17 responses. This DNA vaccination strategy may be a promising adjunctive approach combined with standard therapy to shorten curative TB treatment, and also serves as proof of concept for treating other chronic bacterial infections.

The impact of Mycobacterium tuberculosis complex in the environment on one health approach

Tuberculosis caused by the Mycobacterium tuberculosis complex (MTBC) has become one of the leading causes of death in humans and animals. Current research suggests that the transmission of MTBC in the environment indirectly transmit to humans and animals with subsequent impact on their wellbeing. Therefore, it is of great significance to take One Health approach for understanding the role of MTBC in not only the interfaces of humans and animals, but also environment, including soil, water, pasture, air, and dust, etc., in response to the MTBC infection. In this review, we present the evidence of MTBC transmission from environment, as well as detection and control strategies in this interface, seeking to provide academic leads for the global goal of End Tuberculosis Strategy under multidisciplinary and multisectoral collaborations.

HIF-1 stabilization in T cells hampers the control of Mycobacterium tuberculosis infection

The hypoxia-inducible factors (HIFs) regulate the main transcriptional pathway of response to hypoxia in T cells and are negatively regulated by von Hippel-Lindau factor (VHL). But the role of HIFs in the regulation of CD4 T cell responses during infection with M. tuberculosis isn’t well understood. Here we show that mice lacking VHL in T cells (Vhl cKO) are highly susceptible to infection with M. tuberculosis, which is associated with a low accumulation of mycobacteria-specific T cells in the lungs that display reduced proliferation, altered differentiation and enhanced expression of inhibitory receptors. In contrast, HIF-1 deficiency in T cells is redundant for M. tuberculosis control. Vhl cKO mice also show reduced responses to vaccination. Further, VHL promotes proper MYC-activation, cell-growth responses, DNA synthesis, proliferation and survival of CD4 T cells after TCR activation. The VHL-deficient T cell responses are rescued by the loss of HIF-1α, indicating that the increased susceptibility to M. tuberculosis infection and the impaired responses of Vhl-deficient T cells are HIF-1-dependent.

The role of hypoxia inducible factors in infection and immune response is unclear. Here, the authors study their impact on the regulation of T cells responses during Mycobacteria tuberculosis infection using transcriptomics, flow cytometry and in vivo infection.

Comparing Current and Next-generation Humanized Mouse Models for Advancing HIV and HIV/Mtb Co-infection Studies

In people living with HIV, Mycobacterium tuberculosis (Mtb) is the major cause of death. Due to the increased morbidity/mortality in co-infection, further research is urgently required. A limiting factor to research in HIV and HIV/Mtb co-infection is the lack of accessible in vivo models. Next-generation humanized mice expressing HLA transgenes report improved human immune reconstitution and functionality, which may better recapitulate human disease. This study compares well-established huNRG mice and next-generation HLA I/II-transgenic (huDRAG-A2) mice for immune reconstitution, disease course, and pathology in HIV and TB. HuDRAG-A2 mice have improved engraftment of key immune cell types involved in HIV and TB disease. Upon intravaginal HIV-1 infection, both models developed significant HIV target cell depletion in the blood and tissues. Upon intranasal Mtb infection, both models sustained high bacterial load within the lungs and tissue dissemination. Some huDRAG-A2 granulomas appeared more classically organized, characterized by focal central necrosis, multinucleated giant cells, and foamy macrophages surrounded by a halo of CD4+ T cells. HIV/Mtb co-infection in huNRG mice trended towards worsened TB pathology and showed potential for modeling co-infection. Both huNRG and huDRAG-A2 mice are viable options for investigating HIV and TB, but the huDRAG-A2 model may offer advantages.

Contributory Factors to Successful Tuberculosis Treatment in Southwest Nigeria: A Cross-Sectional Study

Tuberculosis (TB) is one of the oldest human diseases, and preventing treatment failure is critical. This is because TB cases pose a risk to the immediate and remote communities due to the potential for spread, particularly for multidrug-resistant (MDR) strains that have been associated with higher morbidity and mortality rates. Hence, this study looked at the factors that influence TB treatment outcomes in Southwest Nigeria. We conducted a cross-sectional study with 712 TB patients from 25 directly observed treatment short course (DOTS) centers, out of which 566 (79.49%) were new treatment cases, and 102 (14.33%) were retreatment cases. The outcome variable was computed into successful treatment where ‘Yes’ was assigned to TB treatment completed and cured, and ‘No’ was assigned to all the remaining outcomes following the standard TB definition. Independent variables included in the analysis were the patient’s socio-demographic characteristics (such as age, sex, distance from the facility, marital status, family type, education, and computed socioeconomic status from modified DHS household assets), clinical and facility parameters (such as the HIV status, facility of access to healthcare, healthcare workers attitudes, services offered at the facility, appearance of the facility, number of people seeking care and waiting time at the facility). Bivariate analysis showed that HIV status (OR: 3.53, 95% CI: 1.83–6.82; p = 0.001), healthcare worker attitude (OR: 2.13, 95% CI: 1.21–3.74; p = 0.01), services offered at the facility (OR: 0.67, 95% CI: 0.49–0.92; p = 0.01), appearance of facility (OR: 0.67, 95% CI: 0.46–0.98; p = 0.04), and number of people seeking care (OR: 2.47, 95% CI: 1.72–3.55; p = 0.001) were associated with higher odds of successful treatment outcome with statistical significance. After multivariate analysis, reactive HIV status (aOR: 3.37, 95% CI: 1.67–6.80; p = 0.001), positive attitude of healthcare workers (aOR: 2.58, 95% CI: 1.36–4.89; p = 0.04), excellent services offered at the healthcare facility (aOR: 0.53, 95% CI: 0.36–0.78; p = 0.001) and few people seeking care (aOR: 2.10, 95% CI: 1.21–3.84; p = 0.001) became independent significant determinants of successful treatment outcome. The study concluded that reactive HIV status, positive attitude of healthcare workers, few people seeking healthcare, and excellent service provided were all factors that contributed to successful treatment outcomes.

Revealing In Silico that Bacteria's Outer Membrane Proteins may Help our Bodies Replicate and Carry Severe Acute Respiratory Syndrome Coronavirus 2

Some studies in the literature show that viruses can affect bacteria directly or indirectly, and viruses use their own specific ways to do these interactions. Furthermore, it is said that bacteria are prone to attachment mammalian cells during a viral illness using their surface proteins that bind to host extracellular matrix proteins such as fibronectin, fibrinogen, vitronectin, and elastin. A recent study identified the cooperation between bacteria and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in silico, in vitro, and in vivo. Like this study, we hypothesized that more bacteria protein might help SARS-CoV-2 transport and attach to angiotensin-converting enzyme 2 (ACE2). The bacteria's outer membrane proteins (OMPs) we chose were not random; they had to be on the outer surface of the bacteria because these proteins on the outer surface should have a high probability of interacting with both the spike protein and ACE2. We obtained by using bioinformatics tools that there may be binding between both ACE2 and spike protein of these bacteria's OMPs. Protein-protein interaction results also supported our hypothesis. Therefore, based on our predicted results, these bacteria OMPs may help SARS-CoV-2 move in our body, and both find and attach to ACE2. It is expected that these inferences obtained from the bioinformatics results may play a role in the SARS-CoV-2 virus reaching host cells. Thus, it may bring a different perspective to studies on how the virus can infect host cells.

Factors influencing the implementation of TB screening among PLHIV in selected HIV clinics in Ghana: a qualitative study

Background

Decreasing the burden of Tuberculosis (TB) among PLHIV through TB screening is an effective intervention recommended by the World Health Organization (WHO). However, after over a decade of implementation in Ghana, the intervention does not realize the expected outcomes. It is also not well understood whether this lack of success is due to implementation barriers. Our study, therefore, sought to examine the factors influencing the implementation of the intervention among people living with HIV (PLHIV) attending HIV clinics at district hospitals in Ghana.

Methods

This was a qualitative study conducted from 6th to 31 May 2019 in three regions of Ghana. We conducted 17 in-depth interviews (IDIs – comprising two regional, six districts and nine facility TB/HIV coordinators) and eight focus group discussions (FGD – consisting of a total of 65 participants) with HIV care providers. The Consolidated Framework for Implementation Research (CFIR) guided the design of interview guides, data collection and analysis. All responses were digitally audio-recorded and transcribed verbatim for coding and analysis using the Framework Approach. Participants consented to the interview and recording.

Results

The main barriers to TB screening relate to the low commitment of the implementers to screen for TB and limited facility infrastructure for the screening activities. Facilitators of TB screening include (1) ease in TB screening, (2) good communication and referral channels, (3) effective goals and feedback mechanisms, (4) health workers recognizing the need for the intervention and (5) the role of chemical sellers.

Conclusions

Key barriers and facilitators to the intervention are revealed. The study has shown that there is a need to increase HIV care providers and institutional commitment towards TB screening interventions. In addition, cost issues need to be assessed as they are drivers of sustainability. Our study also advances the field of implementation science through CFIR to better understand the factors influencing the implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08295-6.

Immunologic Biomarkers in Peripheral Blood of Persons With Tuberculosis and Advanced HIV

Introduction

Tuberculosis (TB) is a common opportunistic infection among people living with HIV. Diagnostic tests such as culture, Xpert-MTB-RIF, and ULTRA have low sensitivity in paucibacillary TB disease; a blood biomarker could improve TB diagnostic capabilities. We assessed soluble factors to identify biomarkers associated with TB among persons with advanced HIV.

Methods

A case-control (1:1) study was conducted, with participants from Rio de Janeiro and Manaus, Brazil. People living with HIV presenting with CD4 count ≤100 cells/mm3 were eligible to participate. Cases had culture-confirmed TB (N=15) (positive for Mycobacterium tuberculosis [Mtb]); controls had HIV-infection only (N=15). Study visits included baseline, month 2 and end of TB therapy, during which samples of peripheral blood were obtained. A panel containing 29 biomarkers including cytokines, chemokines and growth factors was utilized to assess candidate biomarkers using Luminex technology in cryopreserved EDTA plasma samples. We used neural network analysis, based on machine learning, to identify biomarkers (single or in combination) that best distinguished cases from controls. Additional multi-dimensional analyses provided detailed profiling of the systemic inflammatory environment in cases and controls.

Results

Median CD4 count and HIV-1 RNA load values were similar between groups at all timepoints. Persons with TB had lower body mass index (BMI) (median=19.6, Interquartile Range [IQR]=18.6-22.3) than controls (23.7; IQR: 21.8 = 25.5, p=0.004). TB coinfection was also associated with increased frequency of other comorbidities. The overall profile of plasma cytokines, chemokines and growth factors were distinct between the study groups at all timepoints. Plasma concentrations of IL-15 and IL-10 were on average lower in TB cases than in controls. When used in combination, such markers were able to discriminate between TB cases and controls with the highest degree of accuracy at each study timepoint.

Conclusion

Among persons with advanced HIV, plasma concentrations of IL-15 and IL-10 can be used in combination to identify TB disease regardless of time on anti-TB treatment.

Analogues of Pyrimidine Nucleosides as Mycobacteria Growth Inhibitors

Tuberculosis (TB) is the oldest human infection disease. Mortality from TB significantly decreased in the 20th century, because of vaccination and the widespread use of antibiotics. However, about a third of the world’s population is currently infected with Mycobacterium tuberculosis (Mtb) and the death rate from TB is about 1.4–2 million people per year. In the second half of the 20th century, new extensively multidrug-resistant strains of Mtb were identified, which are steadily increasing among TB patients. Therefore, there is an urgent need to develop new anti-TB drugs, which remains one of the priorities of pharmacology and medicinal chemistry. The antimycobacterial activity of nucleoside derivatives and analogues was revealed not so long ago, and a lot of studies on their antibacterial properties have been published. Despite the fact that there are no clinically used drugs based on nucleoside analogues, some progress has been made in this area. This review summarizes current research in the field of the design and study of inhibitors of mycobacteria, primarily Mtb.

The Role of CD4+CD8+ T Cells in HIV Infection With Tuberculosis

Background

Tuberculosis (TB) is an important opportunistic infection in acquired immunodeficiency diseases (AIDS). Although the frequency of CD4⁺CD8⁺ double-positive (DP) T cells has been observed to increase in pathological conditions, their role (phenotypic and functional) is poorly described, especially in human immunodeficiency virus (HIV) infection with TB (HIV/TB (HT) coinfection).

Methods

The percentage and phenotypic and functional properties of peripheral blood DP T cells in patients with HT coinfection in comparison to uninfected controls and to patients with HIV or TB mono-infection were analyzed by direct intracellular cytokine staining (ICS).

Results

Total and CD4^lowCD8^high DP T cells were significantly increased in patients with both HIV and TB mono-infection, especially in patients with HT coinfection. Compared with healthy controls (HCs), the percentage of DP T cells expressing chemokine receptor 5 (CCR5) in patients with HT coinfection was significantly higher. Compared with HCs and patients with TB, a lower percentage of tumor necrosis factor α (TNF-α) secreting DP T cells and a higher percentage of granzyme A-secreting DP T cells were observed in patients with HIV mono-infection and HT coinfection, respectively. In addition, DP T cells expressed more cytolytic markers (granzyme A and perforin) than CD4⁺ T cells, but similarly to CD8⁺ T cells in patients with HT coinfection.

Conclusions

Our data suggested that HT coinfection resulted in a marked increase in DP T cells, especially the CD4^lowCD8^high subpopulation. DP T cells may be susceptible to HT coinfection, and have the same cytotoxic function as CD8⁺ T cells.

Risk factors for TB in Australia and their association with delayed treatment completion

BACKGROUND: Australia has a low incidence of TB and has committed to eliminating the disease. Identification of risk factors associated with TB is critical to achieving this goal.METHODS: We undertook a prospective cohort study involving persons receiving TB treatment in four Australian jurisdictions. Risk factors and their association with delayed treatment completion (treatment delayed by at least 1 month) were analysed using univariate analyses and multivariate logistic regression.RESULTS: Baseline surveys were completed for 402 persons with TB. Most (86.1%) were born overseas. Exposure to a person with TB was reported by 19.4%. Diabetes mellitus (10.2%), homelessness (9.2%), cigarette smoking (8.7%), excess alcohol consumption (6.0%) and mental illness (6.2%) were other common risk factors. At follow-up, 24.8% of patients had delayed treatment completion, which was associated with adverse events (34.1%, aOR 6.67, 95% CI 3.36-13.27), excess alcohol consumption (6.0%, aOR 21.94, 95% CI 6.03-79.85) and HIV co-infection (2.7%, aOR 8.10, 95% CI 1.16-56.60).CONCLUSIONS: We identified risk factors for TB and their association with delayed treatment completion, not all of which are routinely collected for surveillance purposes. Recognition of these risk factors should facilitate patient-centred care and assist Australia in reaching TB elimination.

The impact of tuberculosis co-infection on virological failure among adults living with HIV in Ethiopia: A systematic review and meta-analysis

Introduction

Tuberculosis (TB) is the most common serious opportunistic infection among people with Human Immunodeficiency Virus (HIV) infection and are considered as the double burden diseases of the world. TB is the leading cause of death among people living with HIV, accounting one in three HIV related deaths. Although TB is responsible for high burden of virological unsuppressed in Ethiopia, there is no national level evidence. Therefore, this systematic review and meta-analysis was aimed at estimating the pooled burden of virological unsuppressed among adults with both HIV-TB and impact of TB on virological failure in Ethiopia.

Methods

The finding of this meta-analysis was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklists. Major data bases PubMed, Scopus, Cochrane Library, Science Direct and Google scholar were searched to access articles. Cochran’s Q statistic quantified with inverse variance was computed to check heterogeneity. Funnel plot visualization and Egger’s test were fitted to assess publication bias across included studies. Random effects model meta-analysis using STATA version-15 statistical software was used to estimate the pooled effect with respective 95% confidence intervals.

Results

A total of 15 primary studies reporting on impact of tuberculosis on virological unsuppressed among adults living with HIV in Ethiopia were eligible for this meta-analysis. Accordingly, the pooled prevalence of virological unsuppressed among adults with both HIV-TB in Ethiopia was 39.09% (95% CI: 29.04, 49.15). In addition, the odds of virological unsuppressed among adults with both HIV-TB was 2.46 times higher when compared with adults living with HIV infection alone (OR = 2.46, 95% CI: 1.74, 3.46).

Conclusion

The present systematic review and meta-analysis evidenced that the pooled prevalence of virological unsuppressed among adults with both HIV-TB was much higher than virological unsuppressed among adults living with HIV alone. Moreover, the odds of virological failure among adults with both HIV-TB was significantly higher when compared with among only HIV infection in Ethiopia. Therefore, strengthening TB prevention interventions, early identification and managing the case and prioritizing viral load monitoring and adherence support among adults living with HIV are recommended.

Discovery of potent antitubercular agents: Design, synthesis and biological evaluation of 4-(3-(4-substitutedpiperazin-1-yl)-quinoxalin-2-yl)-naphthalen-1-ol analogues

A series of twenty-five novel 4-(3-(4-substituted piperazin-1-yl)-quinoxalin-2-yl)-naphthalen-1-ol analogues were synthesized, characterized and screened for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain. These compounds exhibited minimum inhibitory concentration in the range of 1.56-50 μg/mL. Among these derivatives, compounds 5a, 5b, 5f, 5m, 5p, and 5r displayed moderate activity (MIC 6.25 μg/mL). Compounds 5c, 5d, 5g, 5l, and 5o showed significant antitubercular activity (MIC 3.125 μg/mL), while compounds 5h, 5n, and 5q exhibited potent antitubercular activity (MIC 1.56 μg/mL). In addition, MTT assay was performed on the active analogues of the series against mouse macrophage cells to assess the cytotoxic effect of the newly synthesized compounds, and a selectivity index of the compounds was established. Selectivity index values of the most active compounds (5h, 5n, and 5q) are >47, indicating the compounds' suitability for further potential drug development. A molecular docking study was performed to understand the putative binding mode and binding strength of the selected significantly active and weakly active compounds with the target enzyme mycobacterial topoisomerase II using moxifloxacin as standard. In-silico ADME prediction and bioavailability studies of the titled compounds obey Lipinski's rule of five and Jorgensen's rule of three. To further ascertain the structure of the compounds, a suitable single crystal for the compounds 5a, 6, and 7d was developed and studied.

Diagnostic Performance of a Novel CXCL10 mRNA Release Assay for Mycobacterium tuberculosis Infection

One-fourth of the world’s population has been infected with Mycobacterium tuberculosis (M.tb). Although interferon-gamma release assays (IGRAs) have been shown to be valid methods for identifying M.tb infection and auxiliary methods for diagnosis of active tuberculosis (TB), lower sensitivity and higher indeterminate rate were often detected among immunosuppressed patients. IP-10 was an alternative biomarker due to the higher expression level after M.tb antigen stimulation, but whether CXCL10 mRNA (the gene that transcribes for the IP-10 protein) can be used as a target for M.tb infection diagnosis was limited. Therefore, we aimed to evaluate the performance of a novel M.tb-specific CXCL10 mRNA release assay in diagnosis of M.tb infection. Suspected TB patients and healthy controls were prospectively recruited between March 2018 and November 2019 from three hospitals in China. CXCL10 mRNA release assay and traditional interferon-gamma release assay (T-SPOT.TB) were simultaneously performed on peripheral blood. Of the 1,479 participants enrolled in the study, 352 patients with definite TB and 153 healthy controls were analyzed. CXCL10 mRNA release assay provided a sensitivity of 93.9% (95% CI = 90.8–96.2%) and a specificity of 98.0% (95% CI = 94.3–99.6%) in the diagnosis of M.tb infection, respectively, while T-SPOT.TB gave a sensitivity of 94.5% (95% CI = 91.5–96.6%) and a specificity of 100% (95% CI = 97.6–100.0%) in the diagnosis of M.tb infection, respectively. The diagnostic performance of CXCL10 mRNA release assay was consistent with T-SPOT.TB, with a total coincidence rate of 95.0% (95% CI = 93.0–96.9%) and a Cohen’s kappa value of 0.89 (0.84–0.93, p < 0.001). However, among TB patients with HIV co-infection (n = 14), CXCL10 mRNA release assay presented significantly higher positive rate [92.9% (66.1–99.8%) vs. 61.5% (31.6–86.1%), p = 0.029] than those of T-SPOT.TB. These results suggested that M.tb-specific CXCL10 mRNA was a novel and useful target in the diagnosis of M.tb infection.

An Annotated Inventory of Tanzanian Medicinal Plants Traditionally Used for the Treatment of Respiratory Bacterial Infections

This review comprehensively covers and analyzes scientific information on plants used in Tanzanian traditional medicine against respiratory diseases. It covers ethnobotanical and ethnopharmacological information extracted from SciFinder, Google Scholar, and Reaxys as well as the literature collected at the Institute of Traditional Medicine in Dar-es-Salaam. Crude extracts and fractions of 133 plant species have literature reports on antimicrobial bioassays. Of these, 16 plant species had a minimum inhibitory activity of MIC ≤ 50 µg/mL. Structurally diverse compounds were reported for 49 plant species, of which 7 had constituents with MIC ≤ 5 µg/mL against various bacteria: Bryophyllum pinnatum (Lam.) Oken, Warburgia ugandensis Sprague, Diospyros mespiliformis Hochst. ex DC., Cassia abbreviata Oliv., Entada abyssinica A. Rich., Strychnos spinosa Lam., and Milicia excelsa (Welw.) C.C. Berg. The low number of antimicrobial active extracts and compounds suggests that antibacterial and antimycobacterial drug discovery needs to have a fresh look at ethnobotanical information, diverting from too reductionist an approach and better taking into account that the descriptions of symptoms and concepts of underlying diseases are different in traditional African and modern Western medicine. Nevertheless, some structurally diverse compounds found in anti-infective plants are highlighted in this review as worthy of detailed study and chemical modification.