Tuberculosis Research Articles

In vitro Characterization and Drug Release Studies of Ethambutol-Loaded Nanoparticles for Pulmonary Delivery

Background: The development of more effective drug delivery techniques is necessary to increase treatment efficacy and patient compliance since tuberculosis (TB) is still a serious worldwide health concern. Ethambutol is a vital aspect of TB treatment, and using nanoparticles to carry it to the lungs may provide targeted delivery and prolonged release, which might enhance the effectiveness of the treatment. Objective: This work aimed to optimize the formulation for prolonged drug release by synthesizing and assessing ethambutol-loaded nanoparticles using the desolation technique with albumin as the polymer. Additionally, the effects of different drug-polymer ratios and stirring rates were investigated. Methods: Nine formulations of ethambutol-loaded nanoparticles were prepared by varying the drug-polymer ratios (1:1 to 1:2) and stirring speeds (500 to 1500 rpm). Key parameters, such as particle size, drug entrapment efficiency, and zeta potential, were measured. The optimized formulation was selected based on the smallest particle size and highest drug entrapment efficiency. Scanning electron microscopy was used to analyze the surface morphology of the nanoparticles. The in vitro drug release profile of the optimized formulation was studied over 24 hours. Results: Increasing the drug-polymer ratio from 1:1 to 1:2 increased nanoparticle size from 192.1 nm to 605.06 nm and decreased drug entrapment efficiency from 75.7%±0.08 to 34%±0.06. Higher stirring speeds (500 to 1500 rpm) also led to larger particle sizes and reduced drug entrapment due to polymer self-aggregation. Zeta potential values ranged from -5.56 to -25.6 mV. Scanning electron microscopy confirmed smooth, spherical nanoparticles. The optimized formulation, EN-5, exhibited the smallest particle size and highest drug entrapment efficiency. In vitro drug release studies showed a sustained ethambutol release, with 42.66±1.53% released in 12 hours and 79.082±2.98% in 24 hours. Conclusion: Ethambutol-loaded nanoparticles having the ability to transport drugs to the lungs over an extended period of time were developed and optimized in the study. With improved drug delivery systems, the optimized formulation showed notable drug entrapment efficiency and controlled release, suggesting its potential to improve tuberculosis therapy.

Implementation of spirometry screening for post-tuberculosis lung disease (PTLD) among adolescents and adults enrolled within the National Tuberculosis Control Program of Carmelo Hospital in Chókwè District, Mozambique: A hybrid type III effectiveness-implementation study protocol

BackgroundDespite receiving adequate treatment, many tuberculosis (TB) survivors are left with post-tuberculosis complications, possibly due to lung tissue damage incurred during the active period of the disease. Current TB programs worldwide deliver quality care throughout the course of active TB treatment, yet often fail to provide organized follow-up once treatment ends. Post-tuberculosis lung disease (PTLD) is a prominent, yet underrecognized cause of chronic lung disease, managed similarly to chronic respiratory diseases with pharmacotherapy and/or personalized pulmonary rehabilitation interventions. Basic pulmonary rehabilitation packages for people finishing TB treatment are still lacking in low- and middle-income countries (LMICs). We offer a study protocol to evaluate the implementation of spirometry and symptom screening for PTLD among people who have completed TB treatment in a rural district in Mozambique.MethodsThe overall objective of this study is to evaluate the introduction of a new screening program that utilizes symptom screening and spirometry for diagnosing PTLD among adolescents and adults that have completed TB treatment. This research protocol consists of three complementary components: 1) assessing the prevalence of PTLD among patients enrolled in the National TB Control Program (NTCP) at Carmelo Hospital (CHC) in Chókwè District, Mozambique; 2) evaluating anticipated implementation outcomes through the identification of the site-, provider-, and individual-level determinants that either facilitate or hinder the successful adoption, implementation, and maintenance of the spirometry screening program, and 3) evaluating the real-time implementation outcomes/processes in order to provide practical evidence-based key indicators of successful implementation of the spirometry screening program.DiscussionProviding well-organized, evidence-based care for individuals with a history of TB who are experiencing symptoms of PTLD can relieve chronic respiratory issues, enhance quality of life, and potentially lower the risk of further pulmonary infections, including recurrent TB. However, there is a significant gap in the literature regarding the implementation of best practices of HIV and TB health services delivery. Addressing this gap could assist Mozambique in improving diagnosis, treatment, and continuity of care for people formerly living with TB. The insights from this study will help decision-makers improve spirometry screening coverage, enhance intervention effectiveness, and translate our findings to evidence-based programming.Trial registrationISRCTN92021748 retrospectively registered.

Estimation of tuberculosis mortality burden in spain: a review of the major data sources

IntroductionIn Spain, notifications of cases of tuberculosis (TB) are registered through the National Epidemiological Surveillance Network (RENAVE). The Minimum Basic Data Set (CMBD) provides information on hospital discharge and the Statistics National Institute (INE) draws on medical death certificates. This study aimed to describe TB mortality in Spain and to compare estimates across data sources, as well as with EU/EEA countries.Material and MethodsA retrospective study of TB data between 2008 −2021 was performed. Mortality rates (MR) were calculated for the three databases as well as fatality rates (CFR) for TB location and HIV status using RENAVE data. Time trends were calculated and the average MR and annual average percentage change for Spain were compared with EU/EEA countries.ResultsBetween 2008 and 2021, 4127 TB deaths were reported to RENAVE, 3877 to INE and 4775 to CMBD. The MR was 0.62 per 100,000 inhabitants for RENAVE, 0.59 for INE and 0.72 for CMBD. A statistically significant downward annual trend was observed. Highest MR across all databases were found in men and in those over 80 years old. CFR was higher for meningeal TB and for HIV patients with a risk ratio of 2.02 (95%CI: 1.82-2.2; p<0.05).ConclusionAlthough the TB MR in Spain has followed a downward annual trend, it is necessary to continue improving prevention, diagnosis and treatment. This will require comprehensive measurement, better knowledge and better use of all information to complement surveillance systems.

Tuberculosis Treatment Outcomes and Associated Factors at Zewditu Memorial Hospital, Ethiopia

<i>Background:</i> Tuberculosis (TB) remains a leading cause of morbidity and mortality in Ethiopia, with treatment success rates consistently below the WHO target. Various factors contribute to poor treatment outcomes. <i>Objective:</i> To assess treatment outcomes for TB and associated factors at Zewditu Memorial Hospital (ZMH) from 2017 to 2021. <i>Methods:</i> An institutional-based analytical cross-sectional study was conducted using TB logbook data. After bivariable analysis, clinically relevant variables and variables with a p-value < 0.2 were included in multivariable logistic regression analysis. Statistical significance was set at p-value < 0.05. <i>Results:</i> The overall successful treatment outcome (cured or completed) was 197 (83.1%). Factors significantly associated with poor treatment outcomes included age group 35 to 44 years (AOR=4.663; 95% CI: 1.215-17.901), extrapulmonary TB (AOR=3.451; 95% CI: 1.172-10.16), and registration in 2019 (AOR=4.367; 95% CI: 1.2-15.87). <i>Conclusion:</i> The treatment success rate falls short of the national target of 85%, highlighting the need for targeted improvements in TB management. The associations with age and extrapulmonary TB emphasize the necessity for focused control measures. Strengthening targeted TB programs at ZMH is recommended.

Detection of Rifampicin Resistance rpoB Gene Using GeneXpert MTB/RIF Assay in Pulmonary Tuberculosis Cases at Debre Tabor Comprehensive Specialized Hospital, Northwest Ethiopia.

Tuberculosis (TB) is a preventable and treatable disease leading to the second death globally. The evolution of drug resistance in Mycobacterium tuberculosis (MTB), particularly rifampicin resistance (RR), has hampered TB control efforts. Thus, this study aimed to provide information regarding the magnitude of MTB and rifampicin resistance among patients tested using the GeneXpert method. A retrospective analysis was carried out at DTCSH. The study included TB registration logbook data from all patients who visited the hospital and were tested for MTB with the Xpert MTB/RIF assay from 2017 to 2024. The laboratory-based data were entered, cleaned, and analyzed using SPSS version 26 software. Multilogistic regression analysis was employed, and a p value ≤ 0.05 was considered statistically significant. A total of 12,981 patient results were included, of which 8.9% (1160/12,981) were MTB-positive and 7.1% (82/1160) were RR. Individuals aged 15-29 years (AOR = 2.13; 95% CI = 1.55-2.93, p < 0.001), living in rural areas (AOR = 1.23; 95% CI = 1.08-1.41, p = 0.003), and HIV+ (AOR = 1.79; 95% CI = 1.48-2.33, p < 0.001) had a higher risk of developing tuberculosis. While RR was identified in 63.4% (52/82) of new, 24.4% (20/82) of re-treated, and 12.2% (10/82) of failed presumptive TB patients. In this study, MTB and RR trends were high. Productive age groups, rural populations, and HIV patients were at risk. To lessen the burden of this contagious and fatal disease, it is recommended to increase early diagnosis of drug-resistant TB and enhance infection control.

A rare case of peritoneal tuberculosis mimicking peritoneal carcinomatosis: the ongoing challenge

Tuberculosis (TB) is a serious infection that can involve any organ system and present in various forms. About one-third of the world’s population are carriers of latent TB. Although most cases are from a pulmonary origin, there is a rising prevalence of abdominal TB. Patients with pulmonary or extrapulmonary TB are treated similarly through the use of pharmacological therapy. Nonspecific clinical manifestations of TB have made it difficult for clinicians to diagnose. Peritoneal tuberculosis (PTB) is a serious concern as its symptoms overlap with that of many other chronic conditions, especially in those who are immunocompromised. The lack of highly sensitive and specific testing methods has made early intervention difficult, therefore a high index of suspicion is crucial in the progression of the disease. Here, we present a case of a 71-year-old female with a history of abdominal pain, fever, and weakness. Initial investigation with computed tomography (CT) imaging revealed omental fat stranding that pointed towards peritoneal carcinomatosis (PC) from possible recurrence of her ovarian cancer. Further investigation with a peritoneal biopsy was remarkable for caseating granulomas with fat necrosis confirming extrapulmonary TB. This report highlights a rare case of PTB mimicking PC in an elderly patient who is immunocompromised from the use of long-term corticosteroids who continued to decline after pharmacological treatment of the disease.

LncRNA SNHG16 Inhibits Intracellular M. tuberculosis Growth Involving Cathelicidin Pathway, Autophagy, and Effector Cytokines Production.

Long noncoding small nucleolar RNA (LncRNA) host gene 16 (SNHG16) is associated with certain diseases, including cancers. However, its role and mechanism in Mycobacterium tuberculosis (Mtb) infection remain unclear. Here, we demonstrated that SNHG16 expression levels were suppressed in peripheral blood mononuclear cells (PBMCs) and CD14+ monocytes of tuberculosis (TB) patients. SNHG16 was up-regulated by acute Mtb infection of PBMCs from healthy control (HC) subjects. Such TB suppression of SNHG16 was consistent with an immunosuppressive-like state driven by IL-10 signaling as seen in TB patients. Notably, SNHG16 limited Mtb growth in macrophages/monocytes through autophagy and vitamin D receptor (VDR)-dependent cathelicidin (CAMP) antimicrobial pathways. Concurrently, SNHG16 was highly expressed in lymphocytes, including CD8+ and Vγ2 Vδ2 T-cell subsets in HCs. SNHG16 overexpression in lymphocytes allowed them to control Mtb infection in macrophages, and SNHG16 epigenetically increased the expression of anti-Mtb effector cytokines in lymphocytes by developing more accessible chromatin states in gene loci encoding IFN-γ, TNF-α, and Granzyme B. Furthermore, the adoptive transfer of SNHG16-overexpressing human PBMCs into Mtb-infected SCID mice conferred protective immunity against Mtb infection. Thus, SNHG16 drove the induction of pleiotropic effector functions that inhibited intracellular Mtb growth in vitro and in vivo, serving as an immunotherapy target in TB.

Cause of death in patients with tuberculosis: A study based on epidemiological and autopsy records of Western Norway 1931-47

BackgroundWithout treatment, nearly 50 % of tuberculosis (TB) patients die. World Health Organization’s definition of TB deaths does not take into consideration whether the cause of death was TB or other non-TB co-morbid conditions. We aimed to improve our knowledge of the causes of death in patients with TB. MethodsSingle-center retrospective study conducted at Gade Institute of Pathology, Haukeland University Hospital, Bergen, Norway. Autopsy data of 269 patients with TB was collected from autopsy journals, and epidemiological data was collected from Norwegian Official Statistics books for period 1931–1947. ResultsOf all TB deaths reported in epidemiological reports, pulmonary TB accounted for 81 % and extrapulmonary TB for 19 %. However, in autopsy records, only 21 % of cases with active pulmonary TB died because of TB. Extrapulmonary involvement was significantly associated with higher mortality (OR EPTB as compared to PTB; 3.27, CI 1.91 – 5.61) and constituted 79 % of deaths attributable to TB. A significant burden of extrapulmonary TB was found in autopsy records (63 %), while in epidemiological records, only 4 % of cases were reported. ConclusionsExtrapulmonary involvement was a predictor of mortality due to TB in hospitalized TB patients. The contribution of extrapulmonary TB to TB mortality seems to be underestimated because extrapulmonary TB largely remains underdiagnosed and underreported in epidemiological data.

Comparative assessment of the epidemic state of tuberculosis before and during the war in Ukraine

BACKGROUND. The war has a negative impact on patient care and the efficiency of the health care system; access to medical care is limited, coverage of preventive examinations and detection of tuberculosis (TB) are deteriorating. There is a threat of exacerbation of the epidemic situation with TB in Ukraine. OBJECTIVE. To assess the epidemic situation with TB during the war in Ukraine. MATERIALS AND METHODS. Comparison of data from the Ministry of health on TB (epidemiological indicators and indicators on detection, diagnosis and prevention) in the pre-war (2018-2021) and war (2022-2023) periods. RESULTS. The following were revealed: 1) a positive trend towards a decrease in epidemiological indicators of TB in 2018-2020, which slowed down in 2021 due to the COVID-19 pandemic, and a negative trend towards an increase in almost all indicators of TB incidence, separate indicators of mortality from TB and its prevalence in 2022-2023; 2) significant increase in the incidence of TB among contacts and children; 3) increase by ⅓-. of mortality from TB in certain regions; 4) correlation between regional rates of morbidity, mortality and prevalence of TB. In 2018-2023, the following decreased: fluorography examination, tuberculin diagnostics, detection of TB during preventive examinations (by 2-4 times), preventive vaccinations for children of the first year of life, detection of newly diagnosed and recurrent TB by smear, preventive treatment in contacts. CONCLUSIONS. Incidence is a marker of response to negative external factors and the main criterion for assessing the epidemic state of TB during the war. Fluorography examination, tuberculin diagnostics, detection of TB during professional examinations, preventive vaccinations for children of the first year of life, detection of newly diagnosed and recurrent TB by smear, preventive treatment of contacts are the main criteria for evaluating the activity of the anti-TB service during the wartime, since they are the first to significantly respond to the challenges of war.

Long- and short-run asymmetric impacts of climate variation on tuberculosis based on a time series study

Distinguishing between long-term and short-term effects allows for the identification of different response mechanisms. This study investigated the long- and short-run asymmetric impacts of climate variation on tuberculosis (TB) and constructed forecasting models using the autoregressive distributed lag (ARDL) and nonlinear ARDL (NARDL). TB showed a downward trend, peaking in March-May per year. A 1 h increment or decrement in aggregate sunshine hours resulted in an increase of 32 TB cases. A 1 m/s increment and decrement in average wind velocity contributed to a decrement of 3600 and 5021 TB cases, respectively (Wald long-run asymmetry test [WLR] = 13.275, P < 0.001). A 1% increment and decrement in average relative humidity contributed to an increase of 115 and 153 TB cases, respectively. A 1 hPa increment and decrement in average air pressure contributed to a decrease of 318 and 91 TB cases, respectively (WLR = 7.966, P = 0.005). ∆temperature(−), ∆(sunshine hours)( −), ∆(wind velocity)(+) and ∆(wind velocity)(−) at different lags had a meaningful short-run effect on TB. The NARDL outperformed the ARDL in forecasting. Climate variation has significant long- and short-run asymmetric impacts on TB. By incorporating both dimensions of effects into the NARDL, the accuracy of the forecasts and policy recommendations for TB can be enhanced.

Extracorporeal membrane oxygenation for tuberculosis-related acute respiratory distress syndrome: An international multicentre retrospective cohort study

ObjectiveTo report the outcomes of patients with severe tuberculosis (TB)-related acute respiratory distress syndrome (ARDS) on extracorporeal membrane oxygenation (ECMO), including predictors of 90-day mortality and associated complications.MethodsAn international multicenter retrospective study was conducted in 20 ECMO centers across 13 countries between 2002 and 2022.ResultsWe collected demographic data, clinical details, ECMO-related complications, and 90-day survival status for 79 patients (median APACHE II score of 20 [25th to 75th percentile, 16 to 28], median age 39 [28 to 48] years, PaO2/FiO2 ratio of 69 [55 to 82] mmHg before ECMO) who met the inclusion criteria. Thoracic computed tomography showed that 61 patients (77%) had cavitary TB, while 18 patients (23%) had miliary TB. ECMO-related complications included major bleeding (23%), ventilator-associated pneumonia (41%), and bloodstream infections (32%). The overall 90-day survival rate was 51%, with a median ECMO duration of 20 days [10 to 34] and a median ICU stay of 42 days [24 to 65]. Among patients on VV ECMO, those with miliary TB had a higher 90-day survival rate than those with cavitary TB (90-day survival rates of 81% vs. 46%, respectively; log-rank P = 0.02). Multivariable analyses identified older age, drug-resistant TB, and pre-ECMO SOFA scores as independent predictors of 90-day mortality.ConclusionThe use of ECMO for TB-related ARDS appears to be justifiable. Patients with miliary TB have a much better prognosis compared to those with cavitary TB on VV ECMO.

Cost-effectiveness of screening with transcriptional signatures for incipient TB among U.S. migrants.

Host-response-based transcriptional signatures (HrTS) have been developed to identify "incipient tuberculosis (TB)". No study has reported the cost-effectiveness of HrTS for post-arrival migrant screening programs in low-incidence countries. To assess the potential health impact and cost-effectiveness of HrTS for post-arrival TB infection screening among new migrants in the United States. We used a discrete-event simulation model to compare four strategies: (1) no screening for TB infection or incipient TB; (2) 'IGRA-only', screen all with interferon gamma release assay (IGRA), provide TB preventive treatment for IGRA-positives; (3) 'IGRA-HrTS', screen all with IGRA followed by HrTS for IGRA-positives, provide incipient TB treatment for individuals testing positive with both tests; and (4) 'HrTS-only', screen all with HrTS, provide incipient TB treatment for HrTS-positives. We assessed outcomes over the lifetime of migrants entering the U.S. in 2019, assuming HrTS met the WHO Target Product Profile (TPP) optimal criteria. We conducted sensitivity analyses to evaluate the robustness of results. The IGRA-only strategy dominated the HrTS-based strategies under both healthcare sector and societal perspectives, with an incremental cost-effectiveness ratio of $78,943 and $89,431 per quality-adjusted life-years (QALY) gained, respectively. This conclusion was robust to varying costs ($15-300) and characteristics of HrTS, and the willingness-to-pay threshold ($30,000-150,000/ QALY gained), but sensitive to the rate of decline in TB progression risk after U.S. entry. Our findings suggest that HrTS meeting the WHO TPP is unlikely to be a cost-effective component of post-arrival screening for migrants entering the U.S.

Peculiarities of the dynamics of tuberculosis incidence in children in Ukraine

OBJECTIVE. To analyze the dynamics of the epidemiological situation with tuberculosis (TB) in children in Ukraine, taking into account the adverse effects of the coronavirus disease (COVID-19) pandemic and large-scale war. MATERIALS AND METHODS. The epidemiological and statistical indicators of TB incidence in Ukraine were analyzed. RESULTS. During 2022-2023, there was a negative trend in the incidence of TB – an increase in the incidence among all age groups. Among the children with TB, an accretion in the percentage of the most vulnerable contingents – children younger than 1 year old and adolescents (15-17 years old) – has been observed. Simultaneously there were a decrease in the number of children with small, limited forms of TB and an increase in the percentage of patients with bacterial excretion in all age groups. CONCLUSIONS. During the previous 2 years, for obvious reasons, the situation with TB detection, treatment and follow-up has deteriorated significantly. During the war, all children in Ukraine belong to the high-risk group for infection with Mycobacterium tuberculosis and TB disease and need (at the earliest opportunity) a specific screening examination for TB.

Differential requirement of formyl peptide receptor 1 in macrophages and neutrophils in the host defense against Mycobacterium tuberculosis Infection

Formyl peptide receptors (FPR), part of the G-protein coupled receptor superfamily, are pivotal in directing phagocyte migration towards chemotactic signals from bacteria and host tissues. Although their roles in acute bacterial infections are well-documented, their involvement in immunity against tuberculosis (TB) remains unexplored. Here, we investigate the functions of Fpr1 and Fpr2 in defense against Mycobacterium tuberculosis (Mtb), the causative agent of TB. Elevated levels of Fpr1 and Fpr2 were found in the lungs of mice, rabbits and peripheral blood of humans infected with Mtb, suggesting a crucial role in the immune response. The effects of Fpr1 and Fpr2 deletion on bacterial load, lung damage, and cellular inflammation were assessed in a murine TB model utilizing hypervirulent strain of Mtb from the W-Beijing lineage. While Fpr2 deletion had no impact on disease outcome, Fpr1-deficient mice demonstrated improved bacterial control, especially by macrophages. Bone marrow-derived macrophages from these Fpr1−/− mice exhibited an enhanced ability to contain bacterial growth over time. Contrarily, treating genetically susceptible mice with Fpr1-specific inhibitors caused impaired early bacterial control, corresponding with increased Mtb persistence in necrotic neutrophils. Furthermore, ex vivo assays revealed that Fpr1−/− neutrophils were unable to restrain Mtb growth, indicating a differential function of Fpr1 among myeloid cells. These findings highlight the distinct and complex roles of Fpr1 in myeloid cell-mediated immunity against Mtb infection, underscoring the need for further research into these mechanisms for a better understanding of TB immunity.

Molecular and microbiological methods for the identification of nonreplicating Mycobacterium tuberculosis.

Chronic tuberculosis (TB) disease, which requires months-long chemotherapy with multiple antibiotics, is defined by diverse pathological manifestations and bacterial phenotypes. Targeting drug-tolerant bacteria in the host is critical to achieving a faster and durable cure for TB. In order to facilitate this field of research, we need to consider the physiology of persistent MTB during infection, which is often associated with the nonreplicating (NR) state. However, the traditional approach to quantifying bacterial burden through colony enumeration alone only informs on the abundance of live bacilli at the time of sampling, and provides an incomplete picture of the replicative state of the pathogen and the extent to which bacterial replication is balanced by ongoing cell death. Modern approaches to profiling bacterial replication status provide a better understanding of inter- and intra-population dynamics under different culture conditions and in distinct host microenvironments. While some methods use molecular markers of DNA replication and cell division, other approaches take advantage of advances in the field of microfluidics and live-cell microscopy. Considerable effort has been made over the past few decades to develop preclinical in vivo models of TB infection and some are recognized for more closely recapitulating clinical disease pathology than others. Unique lesion compartments presenting different environmental conditions produce significant heterogeneity between Mycobacterium tuberculosis populations within the host. While cellular lesion compartments appear to be more permissive of ongoing bacterial replication, caseous foci are associated with the maintenance of M. tuberculosis in a state of static equilibrium. The accurate identification of nonreplicators and where they hide within the host have significant implications for the way novel chemotherapeutic agents and regimens are designed for persistent infections.

Histopathological spectrum of Cardiac Tuberculosis on autopsy: series of 11 cases

Background: Tuberculosis (TB) is leading cause of morbidity and mortality worldwide. However, this endemic disease rarely involves heart. Cardiac TB can involve any structure of heart with pericarditis is most frequent manifestation. Methods: This retrospective study was conducted at Department of Pathology from January 2012 to December 2020. Autopsy records of all cases suggestive of tuberculosis in any part of heart were selected and slides were reviewed. Results: A total of 11 cases of cardiac TB were recorded on autopsy, including 6 cases of isolated myocarditis, 2 cases of myopericarditis 2 cases of isolated pericarditis and one case of necrotizing arteritis in left coronary artery. Concomitant pulmonary TB was present in 72.7% cases. Conclusion: This study highlights that in all patients of pulmonary tuberculosis with appearance of any cardiovascular sign or symptom, cardiac TB should be suspected as one of the differentials.

Mathematical modeling suggests heterogeneous replication of Mycobacterium tuberculosis in rabbits.

How quickly Mycobacterium tuberculosis ( Mtb ) replicates and dies in lungs of infected individuals is likely to determine the outcome of the infection - either control/clearance of the bacteria by the host immune response or progression to active disease, tuberculosis ( TB ). And yet, only a few studies, primarily in mice, rigorously estimated the rates of Mtb replication and death during an in vivo infection. We infected rabbits with a novel clinical isolate of Mtb carrying an unstable, "replication clock" plasmid and followed the dynamics of bacteria over time. Interestingly, previous methods developed to estimate Mtb replication and death rates using similar data for Mtb infection of mice failed to describe our novel data on Mtb dynamics in rabbits; we showed that heterogeneous dynamics of Mtb in semi-independent subpopulations in lungs of Mtb-infected rabbits may be one explanation of this failure of the method. Our results highlight potential differences in Mtb dynamics in different mammalian hosts and suggest ways to evaluate heterogeneity of Mtb replication and death rates in vivo.

Nanopore-targeted sequencing (NTS) for intracranial tuberculosis: a promising and reliable approach

BackgroundThe World Health Organization predicted 10.6 million new tuberculosis cases and 1.5 million deaths in 2022. Tuberculous meningitis, affecting 1% of active TB cases, is challenging to diagnose due to sudden onset, vague symptoms, and limited laboratory tests. Nanopore-targeted sequencing (NTS) is an emerging third-generation sequencing technology known for its sequencing capabilities. We compared its detection efficiency with Xpert, MTB culture, PCR, and AFB smear in cerebrospinal fluid samples to highlight the substantial potential of NTS in detecting intracranial tuberculosis.MethodsThis study included 122 patients suspected of having intracranial tuberculosis at the Second Hospital of Nanjing in Jiangsu Province, China, between January 2021 and January 2024. The Univariate logistic regression and random forest regression identified risk factors and clinical markers. A chi-square test evaluated diagnostic accuracy for different image types of intracranial tuberculosis.ResultsThe research involved 100 patients with intracranial tuberculosis. Among them, 41 had tuberculous meningitis, 27 had cerebral parenchymal tuberculosis, and 32 had mixed intracranial tuberculosis. Besides, 22 patients were diagnosed with other brain conditions. In diagnosing intracranial tuberculosis, NTS demonstrated a sensitivity of 60.0% (95% CI: 49.7-69.5%) and a specificity of 95.5% (95% CI:75.1-99.8%), with an AUC value of 0.78 (95% CI: 0.71 to 0.84), whose overall performance was significantly better than other detection methods. There was no notable difference (P > 0.05) in diagnostic accuracy between NTS and the final diagnosis for intracranial tuberculosis patients with varying imaging types. Furthermore, patients who tested positive had a 31.500 (95% CI: 6.205-575.913) times higher risk of having intracranial tuberculosis compared to those with negative results.ConclusionDue to its convenience, efficiency, quick turnaround time, and real-time sequencing analysis, NTS might become a promising and reliable method for providing microbiological diagnoses for patients with intracranial tuberculosis and for screening populations at risk.

Risk of tuberculosis after achieving HIV virological suppression on antiretroviral therapy: a Danish nationwide prospective cohort study.

In countries with low tuberculosis (TB) burden, the risk of TB in people with HIV (PWH) once HIV virological suppression is achieved is not fully understood. In a nationwide cohort, we included all adult PWH from the Danish HIV Cohort initiating antiretroviral therapy (ART) (1995-2017) without prior TB disease. We used Kaplan-Meier estimation and Poisson regression to calculate TB incidence rate (IR) after six months of ART, along with associated risk factors and mortality rates (MR). Among 6,849 PWH initiating ART (median follow-up 7.4 years), 84 developed TB (IR 1.4/1000 person-year [PY]), 54 of them beyond six months of ART initiation, IR 0.97/1000 PY (95%CI:1.17-1.79): 1.95 (95%CI:1.34-2.76) in non-Danish born, 0.36 (95%CI:0.21-0.62) in Danish-born without injection drug use (IDU), and 2.95 (95%CI:1.53-5.66) in Danish-born with IDU. Danish-born with suppressed viremia, and no IDU or known TB exposures had the lowest risk (IR 0.05/1000 PY).In the adjusted analysis, being non-Danish born (aIRR 4.27[95%CI:2.36-7.72]), IDU (aIRR 4.95[95%CI:2.55-9.62]), and previous AIDS-defining events (aIRR 2.05[95%CI:1.06-3.94]) raised TB risk, while suppressed HIV-RNA (aIRR 0.58[95%CI:0.34-0.99]) reduced it. The overall MR for HIV/TB co-infected post- ART was high, at 48.9/1000 PY (95%CI:30.4-78.7). The TB risk remains elevated in PWH beyond six months of ART initiation, especially among migrants, IDU, those without suppressed HIV-RNA, and individuals exposed to high TB endemic areas or with social risk determinants of health. Conversely, PWH without these risk factors have a TB risk similar to the general population and would not require targeted TB screening strategies.

A modified BPaL regimen for tuberculosis treatment replaces linezolid with inhaled spectinamides.

The Nix-TB clinical trial evaluated a new 6 month regimen containing three oral drugs; bedaquiline (B), pretomanid (Pa), and linezolid (L) (BPaL regimen) for the treatment of tuberculosis (TB). This regimen achieved remarkable results as almost 90% of the multidrug-resistant or extensively drug-resistant TB participants were cured but many patients also developed severe adverse events (AEs). The AEs were associated with the long-term administration of the protein synthesis inhibitor linezolid. Spectinamide 1599 is also a protein synthesis inhibitor of Mycobacterium tuberculosis with an excellent safety profile, but it lacks oral bioavailability. Here, we propose to replace L in the BPaL regimen with spectinamide (S) administered via inhalation and we demonstrate that inhaled spectinamide 1599, combined with BPa --BPaS regimen--has similar efficacy to that of the BPaL regimen while simultaneously avoiding the L-associated AEs. The BPaL and BPaS regimens were compared in the BALB/c and C3HeB/FeJ murine chronic TB efficacy models. After 4-weeks of treatment, both regimens promoted equivalent bactericidal effects in both TB murine models. However, treatment with BPaL resulted in significant weight loss and the complete blood count suggested the development of anemia. These effects were not similarly observed in mice treated with BPaS. BPaL and BPa, but not the BPaS treatment, also decreased myeloid to erythroid ratio suggesting the S in the BPaS regimen was able to recover this effect. Moreover, the BPaL also increased concentration of proinflammatory cytokines in bone marrow compared to mice receiving BPaS regimen. These combined data suggest that inhaled spectinamide 1599 combined with BPa is an effective TB regimen without L-associated AEs.