Tuberculosis-a World Health Organization Perspective

Rifabutin loaded inhalable β-glucan microparticle based drug delivery system for pulmonary TB

Inhalable microparticle-based anti TB drug delivery systems are being investigated extensively for Tuberculosis [TB] treatment as they offer efficient and deep lung deposition with several advantages over conventional routes. It can reduce the drug dose, treatment duration and toxic effects and optimize the drug bioavailability. Yeast derived β-glucan is a β-[1-3/1-6] linked biocompatible polymer and used as carrier for various biomolecules. Due to presence of glucan chains, particulate glucans act as PAMP and thereby gets internalized via receptor mediated phagocytosis by the macrophages. In this study, β-glucan microparticles were prepared by adding l-leucine as excipient, and exhibited 70% drug [Rifabutin] loading efficiency. Further, the sizing and SEM data of particles revealed a size of 2-4 µm with spherical dimensions. The FTIR and HPLC data confirmed the β-glucan composition and drug encapsulations efficiency of the particles. The mass median aerodynamic diameter [MMAD] and geometric standard deviation [GSD] data indicated that these particles are inhalable in nature and have better thermal stability as per DSC thermogram. These particles were found to be non-toxic upto a concentration of 80 µg/ml and were found to be readily phagocytosed by human macrophage cells in-vitro as well as in-vivo by lung alveolar macrophage. This study provides a framework for future design of inhalable β-glucan particle based host-directed drug delivery system against pulmonary TB.

Impact of Health Education in Combination with Nutrition Support Nursing on the Nutritional Status and Quality of Life in Patients with Pulmonary Tuberculosis

This study aimed to ascertain the effects of health education combined with nutrition support nursing on the nutritional status and quality of life of patients with pulmonary tuberculosis. A clinical study was conducted. Sixty-four patients with tuberculosis were selected as the study participants and divided into control and observation groups (n = 32). Both groups received antituberculosis drugs. The control group received standard nursing care, while the observation group received health education in conjunction with nutrition support nursing. After 3 months of intervention, the total effective treatment rate and adherence were compared. Before and after the intervention, the albumin (ALB), prealbumin (PA), transferrin (TF), and hemoglobin (Hb) level, body mass index (BMI), and Short Form-36 (SF-36) scores were compared. The occurrence of adverse reactions during intervention was recorded. Following the intervention, the observation group exhibited a higher treatment total effective rate and increased levels of ALB, PA, TF, Hb, and BMI compared with the control group (p < 0.05). The observation group demonstrated a higher total adherence rate and a lower incidence of adverse reactions compared with the control group (p < 0.05); the SF-36 score of the observation group was higher than that of the control group (p < 0.05). The integration of health education and nutrition support nursing can effectively enhance the therapeutic outcomes of patients with pulmonary tuberculosis. This approach not only improves their nutritional status, treatment adherence, and quality of life, but also reduces the incidence of adverse reactions. The findings of this study lay a solid foundation for further exploration of the combined effects of health education and nutrition support nursing on pulmonary tuberculosis.

Clinical manifestation and long-term follow-up of presumed ocular tuberculosis in China

Background

This study aimed to report the clinical manifestations of presumed ocular tuberculosis (OTB) and the treatment response after anti-tuberculosis therapy (ATT) in a Chinese population.

Methods

Clinical data, including general characteristics, ocular lesions, visual acuity at baseline, and final follow-up of patients with presumed OTB from 2006 to 2022 in two eye clinics in China, were retrospectively analyzed.

Results

The study included 84 eyes of 52 patients. The following ocular manifestations were observed: anterior uveitis (4.8%), posterior uveitis (34.5%), panuveitis (11.9%), retinal vasculitis (40.5%) and optic neuropathy (8.3%). After ATT, the vision improved by varying degrees in 48 eyes (57.1%), remained stable in 34 eyes (40.5%) and decreased in 2 eyes (2.4%).

Conclusions

OTB is likely to be misdiagnosed as other infectious uveitis and optic neuropathy. Clinical features must be interpreted in conjunction with topical and general laboratory findings and in collaboration with other subspecialties to make a final diagnosis.

Prolonged survival of a patient with active MDR-TB HIV co-morbidity: insights from a Mycobacterium tuberculosis strain with a unique genomic deletion

Coinfection of HIV and multidrug-resistant tuberculosis (MDR-TB) presents significant challenges in terms of the treatment and prognosis of tuberculosis, leading to complexities in managing the disease and impacting the overall outcome for TB patients. This study presents a remarkable case of a patient with MDR-TB and HIV coinfection who survived for over 8 years, despite poor treatment adherence and comorbidities. Whole genome sequencing (WGS) of the infecting Mycobacterium tuberculosis (Mtb) strain revealed a unique genomic deletion, spanning 18 genes, including key genes involved in hypoxia response, intracellular survival, immunodominant antigens, and dormancy. This deletion, that we have called "Del-X," potentially exerts a profound influence on the bacterial physiology and its virulence. Only few similar deletions were detected in other non-related Mtb genomes worldwide. In vivo evolution analysis identified drug resistance and metabolic adaptation mutations and their temporal dynamics during the patient's treatment course.

Disseminated Bacillus Calmette-Guérin infection: role of imaging in the evaluation of complications

BACKGROUND

The Bacillus Calmette-Guerin (BCG) vaccine is generally used to prevent tuberculosis, particularly meningeal and miliary types, in childhood. This vaccine can rarely cause complications of varying severity, ranging from localized disease to a severe diffuse type known as disseminated BCG infection. Imaging modalities play an important role in the evaluation of different complications of disseminated BCG infection. This study aimed to assess and describe the imaging findings of disseminated BCG infection in order to help clinicians diagnose this life-threatening infection more accurately.

METHODS

This retrospective study was performed on 44 hospitalized children diagnosed with disseminated BCG infection. The results of radiographs, sonography, computerized tomography (CT) scan and magnetic resonance imaging were compiled in a checklist and were then assessed by a radiology resident and a board-certificated radiologist. The radiological findings from various imaging modalities were presented descriptively and the frequency of different parameters was reported.

RESULTS

Axillary lymphadenopathy at the vaccinated side was frequent and was often associated with abscesses. However, abscesses in other body regions were uncommon. The most common abdominal imaging findings were enlarged liver and spleen accompanied by multiple hypoechoic and hypodense nodules on ultrasound and CT scans, respectively. Furthermore, diffuse or multifocal pulmonary opacities were the most frequent findings on chest X-rays and CT scans.

CONCLUSION

Characteristic imaging findings of disseminated BCG infection play a vital role in the early diagnosis of this infection. The study findings demonstrated the importance of radiological imaging in the diagnosis and evaluation of the complications of disseminated BCG infection.

The Role of Ultrasound in the Diagnosis of Pulmonary Infection Caused by Intracellular, Fungal Pathogens and Mycobacteria: A Systematic Review

BACKGROUND

Lung ultrasound (LUS) is a widely available technique allowing rapid bedside detection of different respiratory disorders. Its reliability in the diagnosis of community-acquired lung infection has been confirmed. However, its usefulness in identifying infections caused by specific and less common pathogens (e.g., in immunocompromised patients) is still uncertain.

METHODS

This systematic review aimed to explore the most common LUS patterns in infections caused by intracellular, fungal pathogens or mycobacteria.

RESULTS

We included 17 studies, reporting a total of 274 patients with M. pneumoniae, 30 with fungal infection and 213 with pulmonary tuberculosis (TB). Most of the studies on M. pneumoniae in children found a specific LUS pattern, mainly consolidated areas associated with diffuse B lines. The typical LUS pattern in TB consisted of consolidation and small subpleural nodes. Only one study on fungal disease reported LUS specific patterns (e.g., indicating "halo sign" or "reverse halo sign").

CONCLUSIONS

Considering the preliminary data, LUS appears to be a promising point-of-care tool, showing patterns of atypical pneumonia and TB which seem different from patterns characterizing common bacterial infection. The role of LUS in the diagnosis of fungal disease is still at an early stage of exploration. Large trials to investigate sonography in these lung infections are granted.

Association of Sociodemographic Factors with Tuberculosis Outcomes in Mississippi

Tuberculosis (TB) is one of the leading causes of death worldwide. In the US, the national incidence of reported TB cases was 2.16 per 100,000 persons in 2020 and 2.37 per 100,000 persons in 2021. Furthermore, TB disproportionately affects minorities. Specifically, in 2018, 87% of reported TB cases occurred in racial and ethnic minorities in Mississippi. Data from TB patients from the Mississippi Department of Health (2011-2020) were used to examine the association between sociodemographic subgroups (race, age, place of birth, gender, homelessness, and alcohol use) with TB outcome variables. Of the 679 patients with active TB cases in Mississippi, 59.53% were Black, and 40.47% were White. The mean age was 46 ± ten years; 65.1% were male, and 34.9% were female. Among patients with previous TB infections, 70.8% were Black, and 29.2% were White. The rate of previous TB cases was significantly higher among US-born (87.5%) persons compared with non-US-born persons (12.5%). The study suggested that sociodemographic factors play a significant role in TB outcome variables. This research will help public health professionals to develop an effective TB intervention program that addresses sociodemographic factors in Mississippi.

The Diagnostic Value of Medical Thoracoscopy Pleural Biopsy, Ultrasound-guided Pleural Biopsy, and Closed Pleural Biopsy in Tuberculous Pleurisy: A propensity score matching analysis.. [DOI: 10.21203/rs.3.rs-2099835/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background and objective For diagnosis of exudative pleural effusion in tuberculous pleurisy, medical thoracoscopic pleural biopsy (MTPB) enables direct vision and is most widely applied, although ultrasound-guided pleural biopsy (USPB) and closed pleural biopsy (CPB) are also viable. This retrospective study compared the diagnostic efficiencies and safety of USPB, CPB, and MTPB. Methods Patients enrolled from 2014 through 2020 underwent USPB, CPB, or MTPB (n = 69, 69, and 110, respectively). Propensity score matching (PSM) analysis was used to compare the diagnostic sensitivities of CPB, MTPB, and USPB. The secondary outcomes were postoperative complications and hospitalization stay. Results PSM analysis resulted in 40 (USPB vs. CPB), 47 (USPB vs. MTPB), and 52 (CPB vs. MTPB) matched pairs. The diagnostic sensitivities of the USPB and CPB groups were 72.5% and 55.0% (P = 0.162); that of USPB and MTPB were 70.2% and 80.9% (P = 0.337); the CPB and MTPB groups were comparable(P = 0.152). The rates of associated pain and subcutaneous emphysema of the MTPB group were higher than that of the USPB or CPB (P = 0.000, both).Hospitalization time of the MTPB group was longest, and significantly longer than that of the USPB (P = 0.029). Conclusions While the three techniques were similarly effective in diagnosing tuberculous pleurisy, USPB and CPB showed fewer associated complications and shorter hospital stays compared with MTPB. The image guidance offered by USPB benefited reduction in postoperative complications.

Tuberculosis poor treatment outcomes and its determinants in Kilifi County, Kenya: a retrospective cohort study from 2012 to 2019

Background

Tuberculosis (TB) is one of the leading causes of deaths in Africa, monitoring its treatment outcome is essential to evaluate treatment effectiveness. The study aimed to evaluate proportion of poor TB treatment outcomes (PTO) and its determinants during six-months of treatment at Kilifi County, Kenya.

Methods

We conducted a retrospective analysis of data from the TB surveillance system (TIBU) in Kilifi County, Kenya from 2012 to 2019. The outcome of interest was PTO (lost-to-follow-up (LTFU), death, transferred out, treatment failure, drug resistance) or successful treatment (cured or completed treatment). We performed time-stratified (at three months follow-up) survival regression analyses accounting for sub-county heterogeneity to determine factors associated with PTO.

Results

We included 14,706 TB patients, their median (IQR) age was 37 (28–50) years and 8,791 (60%) were males. A total of 13,389 (91%) were on first line anti-TB treatment (2RHZE/4RH), 4,242 (29%) were HIV infected and 192 (1.3%) had other underlying medical conditions. During 78,882 person-months of follow-up, 2,408 (16%) patients had PTO: 1,074 (7.3%) deaths, 776 (5.3%) LTFU, 415 (2.8%) transferred out, 103 (0.7%) treatment failure and 30 (0.2%) multidrug resistance. The proportion of poor outcome increased from 7.9% in 2012 peaking at 2018 (22.8%) and slightly declining to 20% in 2019 (trend test P = 0.03). Over two-thirds 1,734 (72%) poor outcomes occurred within first three months of follow-up. In the first three months of TB treatment, overweight ((aHR 0.85 (95%CI 0.73–0.98), HIV infected not on ARVS (aHR 1.72 (95% CI 1.28–2.30)) and year of starting treatment were associated with PTO. However, in the last three months of treatment, elderly age ≥50 years (aHR 1.26 (95%CI 1.02–1.55), a retreatment patient (aHR 1.57 (95%CI 1.28–1.93), HIV infected not on ARVs (aHR 2.56 (95%CI 1.39–4.72), other underlying medical conditions (aHR 2.24 (95%CI 1.41–3.54)) and year of starting treatment were positively associated with PTO while being a female (aHR 0.83 (95%CI 0.70–0.97)) was negatively associated with PTO.

Conclusions

Over two-thirds of poor outcomes occur in the first three months of TB treatment, therefore greater efforts are needed during this phase. Interventions targeting HIV infected and other underlying medical conditions, the elderly and retreated patients provide an opportunity to improve TB treatment outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00807-4.

Levofloxacin-Loaded Nanosonosensitizer as a Highly Efficient Therapy for Bacillus Calmette-Guérin Infections Based on Bacteria-Specific Labeling and Sonotheranostic Strategy

Purpose

The rapid emergence of multidrug-resistant Mycobacterium tuberculosis (MTB) poses a significant challenge to the treatment of tuberculosis (TB). Sonodynamic antibacterial chemotherapy (SACT) combined with sonosensitizer-loaded nanoparticles with targeted therapeutic function is highly expected to eliminate bacteria without fear of drug resistance. This study aimed to investigate the antibacterial effect and underlying mechanism of levofloxacin-loaded nanosonosensitizer with targeted therapeutic function against Bacillus Calmette-Guérin bacteria (BCG, an MTB model).

Methods

This study developed levofloxacin-loaded PLGA-PEG (poly lactide-co-glycolide-polyethylene glycol) nanoparticles with BM2 aptamer conjugation on its surface using the crosslinking agents EDC and NHS (BM2-LVFX-NPs). The average diameter, zeta potential, morphology, drug-loading properties, and drug release efficiency of the BM2-LVFX-NPs were investigated. In addition, the targeting and toxicity of BM2-LVFX-NPs in the subcutaneous BCG infection model were evaluated. The biosafety, reactive oxygen species (ROS) production, cellular phagocytic effect, and antibacterial effect of BM2-LVFX-NPs in the presence of ultrasound stimulations (42 kHz, 0.67 W/cm², 5 min) were also systematically evaluated.

Results

BM2-LVFX-NPs not only specifically recognized BCG bacteria in vitro but also gathered accurately in the lesion tissues. Drugs loaded in BM2-LVFX-NPs with the ultrasound-responsive feature were effectively released compared to the natural state. In addition, BM2-LVFX-NPs exhibited significant SACT efficiency with higher ROS production levels than others, resulting in the effective elimination of bacteria in vitro. Meanwhile, in vivo experiments, compared with other options, BM2-LVFX-NPs also exhibited an excellent therapeutic effect in a rat model with BCG infection after exposure to ultrasound.

Conclusion

Our work demonstrated that a nanosonosensitizer formulation with LVFX could efficiently translocate therapeutic drugs into the cell and improve the bactericidal effects under ultrasound, which could be a promising strategy for targeted therapy for MTB infections with high biosafety.

Tuberculosis stigma: Assessing tuberculosis knowledge, attitude and preventive practices in surulere, Lagos, Nigeria

Context

Tuberculosis (TB), though preventable and curable, remains a global health problem, ranked one of the top causes of death worldwide, despite the World Health Organization's strategies. This may be due to the stigma surrounding the disease.

Aim

This study assesses TB stigma in light of knowledge, attitudes, and preventive practices among individuals in an urban community.

Settings and Design

This was a descriptive, cross-sectional study among 317 residents of Surulere, Lagos, Nigeria, selected by multi-stage sampling.

Subjects and Methods

Data were collected using a pretested, semi-structured, interviewer-administered questionnaire and analyzed using Epi InfoTM version 7.2.2.6 2018 (Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA).

Statistical Analysis Used

Descriptive variables were summarized as frequencies, and the Chi-square test was used to test the associations. The level of significance was predetermined at P ≤0.05.

Results

Most participants were between the age group of 21 and 40 years. Approximately 9 out of every 10 respondents (91.8%) were aware of TB. Overall, only 2.4% of respondents had good knowledge of TB, more than half (59.1%) had positive attitudes toward TB, about one-third (37.1%) had good preventive practices and 22.7% of respondents expressed TB stigma, 63.6% would show no compassion or desire to help people with TB while 64.3% would rather people with TB were never employed. However, good knowledge translated into less stigma (P <0.001).

Conclusions

Most participants were aware of TB, although knowledge, attitude, and practice levels were poor. Knowledge was found to reduce TB stigma, reinforcing the need for improved community literacy regrading TB. This has the potential to influence health-seeking behavior and promote better TB prevention, detection, and treatment outcomes.

Can Thin Layer Agar Test Play a Key Role in the Diagnosis of Tuberculosis in Low-Resource Settings?

Background: Fast, reliable, and cost-effective tests are recommended for tuberculosis diagnosis and drug susceptibility testing, especially in resource-limited settings. Objectives: This study aimed to evaluate the performance of thin-layer agar for tuberculosis diagnosis and drug susceptibility testing. Methods: Samples were collected from patients with presumptive tuberculosis and tested using thin-layer agar for tuberculosis and drug susceptibility testing in parallel with Lowenstein Jensen culture method for tuberculosis diagnosis and proportion method for drug susceptibility testing as the gold standard. Receiver operating characteristic curve analysis was performed to calculate the performance parameters. Results: Thin-layer agar method showed sensitivity and specificity values of 96.63% and 62.50%, respectively, for the isolation of Mycobacterium tuberculosis directly from specimens. Drug susceptibility results using thin-layer agar showed sensitivity values for isoniazid, rifampicin), ethambutol and streptomycin were 94.74%, 86.84%, 94.74% and 81.58%, respectively, while the specificity values were 100%, 100%, 86.27% and 100% for isoniazid, rifampicin, ethambutol and streptomycin, respectively. Results were available in a median time of 16 days for thin-layer agar and 25 days for the conventional method. Conclusions: The thin-layer agar method is a relatively rapid, simple, and cost-effective method for the diagnosis and drug susceptibility testing of M. tuberculosis. It may be a useful tool for establishing tuberculosis laboratories in resource-limited settings because it does not require expensive equipment and a high level of training. Our study may help in choosing the appropriate treatment and control of tuberculosis.

Molecular Dynamics Studies of Therapeutic Liquid Mixtures and Their Binding to Mycobacteria

Tuberculosis is an highly contagious disease still considered by the WHO as one of most infectious diseases worldwide. The therapeutic approach, used to prevent and treat tuberculosis targets the Mycobacterium tuberculosis complex, comprises a combination of drugs administrated for long periods of time, which, in many cases, could cause several adverse effects and, consequently, low compliance of the patient to the treatment and drug-resistance. Therefore, therapeutic liquid mixtures formulated with anti-tuberculosis drugs and/or adjuvants in tuberculosis therapy are an interesting approach to prevent toxic effects and resistance to anti-tuberculosis drugs. The herein formulated therapeutic liquid mixtures, including ethambutol, arginine, citric acid and water under different molar ratios, were studied through a molecular dynamics approach to understand how ethambutol and arginine could be stabilized by the presence of citric acid and/or water in the mixture. To gain insights on how the uptake of these mixtures into the mycobacteria cell may occur and how a mycobacterial ABC transporter could contribute to this transport, multiple simultaneous ligand docking was performed. Interactions between citric acid and ethambutol involving the carboxyl and hydroxyl groups of citric acid with the amines of ethambutol were identified as the most critical ones. Water molecules present in the mixture provides the necessary network of hydrogen bonds that stabilize the mixture. Molecular docking additionally provided an interesting hypothesis on how the different mixture components may favor binding of ethambutol to an ABC importer. The data presented in this work helps to better understand these mixtures as well as to provide cues on the mechanisms that allow them to cross the mycobacterial cell membrane.

Heme Oxygenase-1 as a Pharmacological Target for Host-Directed Therapy to Limit Tuberculosis Associated Immunopathology

Excessive inflammation and tissue damage are pathological hallmarks of chronic pulmonary tuberculosis (TB). Despite decades of research, host regulation of these clinical consequences is poorly understood. A sustained effort has been made to understand the contribution of heme oxygenase-1 (HO-1) to this process. HO-1 is an essential cytoprotective enzyme in the host that controls inflammation and oxidative stress in many pathological conditions. While HO-1 levels are upregulated in animals and patients infected with Mycobacterium tuberculosis (Mtb), how it regulates host responses and disease pathology during TB remains unclear. This lack of clarity is due in part to contradictory studies arguing that HO-1 induction contributes to both host resistance as well as disease progression. In this review, we discuss these conflicting studies and the role of HO-1 in modulating myeloid cell functions during Mtb disease progression. We argue that HO-1 is a promising target for host-directed therapy to improve TB immunopathology.

Tuberculous Lymphadenitis in a Patient Receiving PD-1 Inhibitor for Melanoma: A Case Report and Brief Literature Review

Oncolytic immunotherapy is a novel and promising approach in clinical oncology practice. Currently, immune checkpoint inhibitors (ICIs) are the first-line treatment options for disseminated melanoma. Nivolumab is a well-defined ICI that blocks programmed cell death 1 (PD-1) and mainly increases anti-tumor immunity. The opportunistic infections are not expected with ICI therapies due to their immune reactivation effects. To date, only a few cancer patients have been reported with activated TB during ICI therapy. Here, we presented a young female patient diagnosed with histologically-confirmed tuberculous lymphadenitis while on nivolumab therapy for metastatic melanoma. The current case report represents the first described tuberculous lymphadenitis case related to anti-PD-1 based monoclonal antibody therapy. The mechanism underlying the development of TB with PD-1 inhibitor use has not been illuminated yet. Triggering of excessive inflammatory responses with ICIs therapy is a potential cause. Considering the increased utilization of ICI-based immunotherapies, the TB screening should be considered in all patients before starting PD-1 inhibitor therapy.

A synergistic bactericidal effect of low-frequency and low-intensity ultrasound combined with levofloxacin-loaded PLGA nanoparticles on M. smegmatis in macrophages

Purpose

Tuberculosis (TB) is a highly infectious disease caused by Mycobacterium tuberculosis (Mtb), which often parasites in macrophages. This study is performed to investigate the bactericidal effect and underlying mechanisms of low-frequency and low-intensity ultrasound (LFLIU) combined with levofloxacin-loaded PLGA nanoparticles (LEV-NPs) on M. smegmatis (a surrogate of Mtb) in macrophages.

Methods and results

The LEV-NPs were prepared using a double emulsification method. The average diameter, zeta potential, polydispersity index, morphology, and drug release efficiency in vitro of the LEV-NPs were investigated. M. smegmatis in macrophages was treated using the LEV-NPs combined with 42 kHz ultrasound irradiation at an intensity of 0.13 W/cm² for 10 min. The results showed that ultrasound significantly promoted the phagocytosis of nanoparticles by macrophages (P < 0.05). In addition, further ultrasound combined with the LEV-NPs promoted the production of reactive oxygen species (ROS) in macrophage, and the apoptosis rate of the macrophages was significantly higher than that of the control (P < 0.05). The transmission electronic microscope showed that the cell wall of M. smegmatis was ruptured, the cell structure was incomplete, and the bacteria received severe damage in the ultrasound combined with the LEV-NPs group. Activity assays showed that ultrasound combined with the LEV-NPs exhibited a tenfold higher antibacterial activity against M. smegmatis residing inside macrophages compared with the free drug.

Conclusion

These data demonstrated that ultrasound combined with LEV-NPs has great potential as a therapeutic agent for TB.

Viral, bacterial, and fungal infections of the oral mucosa: Types, incidence, predisposing factors, diagnostic algorithms, and management

For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.

Isoniazid acetylation phenotypes in the Sudanese population; findings and implications

Background

Isoniazid (INH) is the mainstay antimicrobial in the treatment of tuberculosis (TB). It is acetlylated in the liver to acetyl-INH. However, there is variation in rate of acetylation of INH among TB patients (i.e. fast, intermediate or slow acetylators) which impacts on the treatment outcomes.

Aim

The isoniazid acetylation phenotypes in the expatriate Sudanese population were determined to provide future guidance since TB is prevalent in Sudan.

Methods

A community-based trial among Sudanese expatriates in Saudi Arabia was undertaken to identify INH-acetylation phenotypes. After overnight fasting, a single dose of 200 mg of INH was given to the volunteers. Three hours later, 5 ml of blood were drawn from each volunteer and prepared for High-Performance Liquid Chromatography (HPLC) analysis. The main outcomes were INH and Acetyl-INH concentrations in plasma and the subsequent Acetyl-INH/INH metabolic ratio (MR).

Results

The findings suggest that slow acetylation is highly prevalent among the study participants (n = 43; 84.31%). Moreover, there was no statistically significant correlation between age and the MR (r = −0.18, P = 0.20). Further, there was no significant association between gender and the MR (P = 0.124). Similarly, no significant association was found between smoking habits and MR (P = 0.24).

Conclusion

Isoniazid phenotyping suggests predominantly slow acetylation among the Sudanese in this sample. The study found no statistically significant associations between the MR and age or gender or smoking.

Comprehensive Comparative Analysis of Cholesterol Catabolic Genes/Proteins in Mycobacterial Species

In dealing with Mycobacterium tuberculosis, the causative agent of the deadliest human disease—tuberculosis (TB)—utilization of cholesterol as a carbon source indicates the possibility of using cholesterol catabolic genes/proteins as novel drug targets. However, studies on cholesterol catabolism in mycobacterial species are scarce, and the number of mycobacterial species utilizing cholesterol as a carbon source is unknown. The availability of a large number of mycobacterial species’ genomic data affords an opportunity to explore and predict mycobacterial species’ ability to utilize cholesterol employing in silico methods. In this study, comprehensive comparative analysis of cholesterol catabolic genes/proteins in 93 mycobacterial species was achieved by deducing a comprehensive cholesterol catabolic pathway, developing a software tool for extracting homologous protein data and using protein structure and functional data. Based on the presence of cholesterol catabolic homologous proteins proven or predicted to be either essential or specifically required for the growth of M. tuberculosis H37Rv on cholesterol, we predict that among 93 mycobacterial species, 51 species will be able to utilize cholesterol as a carbon source. This study’s predictions need further experimental validation and the results should be taken as a source of information on cholesterol catabolism and genes/proteins involved in this process among mycobacterial species.

Cell Wall Hydrolytic Enzymes Enhance Antimicrobial Drug Activity Against Mycobacterium

Cell wall hydrolases are enzymes that cleave bacterial cell walls by hydrolyzing specific bonds within peptidoglycan and other portions of the envelope. Two major sources of hydrolases in nature are from hosts and microbes. This study specifically investigated whether cell wall hydrolytic enzymes could be employed as exogenous reagents to augment the efficacy of antimicrobial agents against mycobacteria. Mycobacterium smegmatis cultures were treated with ten conventional antibiotics and six anti-tuberculosis drugs-alone or in combination with cell wall hydrolases. Culture turbidity, colony-forming units (CFUs), vital staining, and oxygen consumption were all monitored. The majority of antimicrobial agents tested alone only had minimal inhibitory effects on bacterial growth. However, the combination of cell wall hydrolases and most of the antimicrobial agents tested, revealed a synergistic effect that resulted in significant enhancement of bactericidal activity. Vital staining showed increased cellular damage when M. smegmatis and Mycobacterium bovis bacillus Calmette-Guérin (M. bovis BCG) were treated with both drug and lysozyme. Respiration analysis revealed stress responses when cells were treated with lysozyme and drugs individually, and an acute increase in oxygen consumption when treated with both drug and lysozyme. Similar trends were also observed for the other three enzymes (hydrolase-30, RipA-His₆ and RpfE-His₆) evaluated. These findings demonstrated that cell wall hydrolytic enzymes, as a group of biological agents, have the capability to improve the potency of many current antimicrobial drugs and render ineffective antibiotics effective in killing mycobacteria. This combinatorial approach may represent an important strategy to eliminate drug-resistant bacteria.

TNF-α blockade impairs in vitro tuberculous granuloma formation and down modulate Th1, Th17 and Treg cytokines

Tuberculosis (TB) is a granulomatous disease that has affected humanity for thousands of years. The production of cytokines, such as IFN-γ and TNF-α, is fundamental in the formation and maintenance of granulomas and in the control of the disease. Recently, the introduction of TNF-α-blocking monoclonal antibodies, such as Infliximab, has brought improvements in the treatment of patients with chronic inflammatory diseases, but this treatment also increases the risk of reactivation of latent tuberculosis. Our objective was to analyze, in an in vitro model, the influence of Infliximab on the granulomatous reactions and on the production of antigen-specific cytokines (TNF-α, IFN-γ, IL-12p40, IL-10 and IL-17) from beads sensitized with soluble Bacillus Calmette-Guérin (BCG) antigens cultured in the presence of peripheral blood mononuclear cells (PBMC) from TB patients. We evaluated 76 individuals, with tuberculosis active, treated and subjects with positive PPD. Granuloma formation was induced in the presence or absence of Infliximab for up to 10 days. The use of Infliximab in cultures significantly blocked TNF-α production (p <0.05), and led to significant changes in granuloma structure, in vitro, only in the treated TB group. On the other hand, there was a significant reduction in the levels of IFN-γ, IL-12p40, IL-10 and IL-17 after TNF-α blockade in the three experimental groups (p <0.05). Taken together, our results demonstrate that TNF-α blockade by Infliximab directly influenced the structure of granuloma only in the treated TB group, but negatively modulated the production of Th1, Th17 and regulatory T cytokines in the three groups analyzed.

GI-19007, a Novel Saccharomyces cerevisiae-Based Therapeutic Vaccine against Tuberculosis

As yet, very few vaccine candidates with activity in animals against Mycobacterium tuberculosis infection have been tested as therapeutic postexposure vaccines. We recently described two pools of mycobacterial proteins with this activity, and here we describe further studies in which four of these proteins (Rv1738, Rv2032, Rv3130, and Rv3841) were generated as a fusion polypeptide and then delivered in a novel yeast-based platform (Tarmogen) which itself has immunostimulatory properties, including activation of Toll-like receptors. This platform can deliver antigens into both the class I and class II antigen presentation pathways and stimulate strong Th1 and Th17 responses. In mice this fusion vaccine, designated GI-19007, was immunogenic and elicited strong gamma interferon (IFN-γ) and interleukin-17 (IL-17) responses; despite this, they displayed minimal prophylactic activity in mice that were subsequently infected with a virulent clinical strain. In contrast, in a therapeutic model in the guinea pig, GI-19007 significantly reduced the lung bacterial load and reduced lung pathology, particularly in terms of secondary lesion development, while significantly improving survival in one-third of these animals. In further studies in which guinea pigs were vaccinated with BCG before challenge, therapeutic vaccination with GI-19007 initially improved survival versus that of animals given BCG alone, although this protective effect was gradually lost at around 400 days after challenge. Given its apparent ability to substantially limit bacterial dissemination within and from the lungs, GI-19007 potentially can be used to limit lung damage as well as facilitating chemotherapeutic regimens in infected individuals.

Host-Directed Therapeutic Strategies for Tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of morbidity and mortality in humans worldwide. Currently, the standard treatment for TB involves multiple antibiotics administered for at least 6 months. Although multiple antibiotics therapy is necessary to prevent the development of drug resistance, the prolonged duration of treatment, combined with toxicity of drugs, contributes to patient non-compliance that can leads to the development of drug-resistant Mtb (MDR and XDR) strains. The existence of comorbid conditions, including HIV infection, not only complicates TB treatment but also elevates the mortality rate of patients. These facts underscore the need for the development of new and/or improved TB treatment strategies. Host-directed therapy (HDT) is a new and emerging concept in the treatment of TB, where host response is modulated by treatment with small molecules, with or without adjunct antibiotics, to achieve better control of TB. Unlike antibiotics, HDT drugs act by directly modulating host cell functions; therefore, development of drug resistance by infecting Mtb is avoided. Thus, HDT is a promising treatment strategy for the management of MDR- and XDR-TB cases as well as for patients with existing chronic, comorbid conditions such as HIV infection or diabetes. Functionally, HDT drugs fine-tune the antimicrobial activities of host immune cells and limit inflammation and tissue damage associated with TB. However, current knowledge and clinical evidence is insufficient to implement HDT molecules as a stand-alone, without adjunct antibiotics, therapeutic modality to treat any form of TB in humans. In this review, we discuss the recent findings on small molecule HDT agents that target autophagy, vitamin D pathway, and anti-inflammatory response as adjunctive agents along with standard antibiotics for TB therapy. Data from recent publications show that this approach has the potential to improve clinical outcome and can help to reduce treatment duration. Thus, HDT can contribute to global TB control programs by potentially increasing the efficiency of anti-TB treatment.

Obstructive uropathy as initial presentation of genitourinary tuberculosis and masquerading as a postsurgical complication

A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight loss. On renal imaging, she was found to have bilateral hydronephrosis and hydroureters in the setting of bilateral distal ureteric obstruction complicated with acute kidney injury and severe hyperkalaemia requiring haemodialysis. The initial concern was for ureteric injury, a known complication of abdominal hysterectomy procedures, however, a urological intervention, performed 9 months later to relieve the ureteric obstruction, revealed purulent material within the left ureter that was smear positive for acid fast bacilli. A GeneXpert test was positive for Mycobacterium tuberculosis She was diagnosed with genitourinary tuberculosis and responded well to antitubercular treatment and haemodialysis was discontinued after the surgery relieved her ureteric obstruction.

Magnetic resonance imaging of bacterial and tuberculous spondylodiscitis with associated complications and non-infectious spinal pathology mimicking infections: a pictorial review

Magnetic resonance (MR) imaging plays an important role in the evaluation of bacterial and tuberculous spondylodiscitis and associated complications. Owing to its high sensitivity and specificity, it is a powerful diagnostic tool in the early diagnosis of ongoing infections, and thus provides help in prompt initiation of appropriate, therapy which may be medical or surgical, by defining the extent of involvement and detection of complications such as epidural and paraspinal abscesses. More specifically, MR imaging helps in differentiating bacterial from tuberculous infections and enables follow up of progression or resolution after appropriate treatment. However, other non-infectious pathology can demonstrate similar MR imaging appearances and one should be aware of these potential mimickers when interpreting MR images. Radiologists and other clinicians need to be aware of these potential mimics, which include such pathologies as Modic type I degenerative changes, trauma, metastatic disease and amyloidosis. In this pictorial review, we will describe and illustrate imaging findings of bacterial and tuberculous spondylodiscitis, their complications and non-infectious pathologies that mimic these spinal infections.

Tuberculosis Infection: Occurrence and Risk Factors in Presumptive Tuberculosis Patients of the Serengeti Ecosystem in Tanzania

Background

Cross-species tuberculosis (TB) transmission between humans and animals has been reported for quite a long time in sub-Saharan Africa. Because humans and animals coexist in the same ecosystem, exploring their potential for cross-species transmission and the impact the disease may have on the health of humans, animals, and their products is critical.

Objectives

This study aimed to identify risk factors for transmission of TB (Mycobacterium tuberculosis) and to assess the potential for zoonotic TB (Mycobacterium bovis) transmission in the Serengeti ecosystem where humans and animals are in intense contact. Our aim is to create a base for future implementation of appropriate control strategies to limit infection in both humans and animals.

Methodology

We administered a semi-structured questionnaire to 421 self-reporting patients to gather information on risk factors and TB occurrence. In a parallel study, researchers screened sputum smears using Ziehl-Neelsen staining and confirmed by mycobacterial culture. We then performed descriptive statistics (Pearson's chi-square test) and logistic regression analysis to establish frequencies, association, and quantification of the risk factors associated with TB cases.

Results

Our findings showed 44% (95% confidence interval [CI], 0.40-0.49) of the results were positive from sputum samples collected over a 1-year duration in areas with a high TB burden, particularly the Bunda district, followed by the Serengeti and Ngorongoro districts. Of the culture-positive patients who also had infections other than TB (43/187 patients), 21 (49%) were HIV positive. Contact with livestock products (odds ratio [OR] 6.0; 95% CI, 1.81-19.9), infrequent milk consumption (OR 2.5; 95% CI, 1.42-4.23), cigarette smoking (OR 2.9; 95% CI, 1.19-7.1.2), and alcohol consumption (OR 2.3; 95% CI, 1.22-4.23) were associated with a higher likelihood of TB infection.

Conclusion

There was no evidence of direct cross-species transmission of either M tuberculosis or M bovis between humans and animals using the study methods. The absence of cross-species TB transmission could be due to limited chances of contact rather than an inability of cross-species disease transmission. In addition, not all people with presumptive TB are infected with TB, and therefore control strategies should emphasise confirming TB status before administering anti-TB drugs.