Multidrug-resistant pulmonary & extrapulmonary tuberculosis: A 13 years retrospective hospital-based analysis

Next-Gen Dual Transcriptomics for Adult Extrapulmonary Tuberculosis Biomarkers and Host-Pathogen Interplay in Human Cells: A Strategic Review

Tuberculosis (TB) is a major public health concern that results in significant morbidity and mortality, particularly in middle- to low-income countries. Extra-pulmonary tuberculosis (EPTB) in adults is a form of TB that affects organs other than the lungs and is challenging to diagnose and treat due to a lack of accurate early diagnostic markers and inadequate knowledge of host immunity. Next-generation sequencing-based approaches have shown potential for identifying diagnostic biomarkers and host immune responses related to EPTB. This strategic review discusses on the significance using primary human cells and cell lines for in vitro transcriptomic studies on common forms of EPTB, such as lymph node TB, brain TB, bone TB, and endometrial TB to derive potential insights. While organoids have shown promise as a model system, primary cell lines still remain a valuable tool for studying host-pathogen interplay due to their conserved immune system, non-iPSC origin, and lack of heterogeneity in cell population. This review outlines a basic workflow for researchers interested in performing transcriptomics studies in EPTB, and also discusses the potential of cell-line based dual RNA-Seq technology for deciphering comprehensive transcriptomic signatures, host-pathogen interplay, and biomarkers from the host and Mycobacterium tuberculosis. Thus, emphasizing the implementation of this technique which can significantly contribute to the global anti-TB effort and advance our understanding of EPTB.

Graphical Abstract

Risk factors associated with drug-resistant tuberculosis in Ethiopia: A systematic review and meta-analysis

The emergence of drug-resistant tuberculosis (DR-TB) is becoming a challenge to the national TB control programmes including Ethiopia. Different risk factors are associated with DR-TB. Identifying these risk factors in a local setting is important to strengthen the effort to prevent and control DR-TB. Thus, this study aimed to assess the risk factors associated with DR-TB in Ethiopia. The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist was followed to conduct this study. We systematically searched the articles from electronic databases and grey literature sources. We used the JBI tools to assess the quality of studies. Data were analysed using STATA version 15. We estimated the pooled odds ratio (OR) along with 95% Confidence Interval (CI). The forest plot and I2 heterogeneity test were used to assess heterogeneity among studies. We explored the presence of publication bias through visual inspection of the funnel plot and Egger's regression test. After screening 2238 articles, 27 studies were included in the final analysis. Based on the pooled analysis of the OR, unemployment (OR; 2.71, 95% CI; 1.64, 3.78), previous TB history (OR; 4.83, 95% CI; 3.02, 6.64), contact with known TB patient (OR; 1.72, 95% CI; 1.05, 2.40), contact with the known multi-drug resistant (MDR) TB patient (OR; 2.54, 95% CI; 1.46, 3.63) and having pulmonary TB (PTB; OR; 1.80, 95% CI; 1.14, 2.45) were found to be the risk factors of DR-TB, while elders (OR; 0.77, 95%CI; 0.60, 0.95) including above 45 years (OR; 0.76, 95%CI; 0.55, 0.97) and males (OR; 0.86, 95%CI; 0.76, 0.97) had lower DR-TB risk, compared to their counterparts. A previous history of TB treatment is a major risk factor for acquiring DR-TB in Ethiopia that might be due to poor adherence during the first-line anti-TB treatment. Besides, having contact with a TB patient, contact with an MDR-TB patient, having PTB and being unemployed were the risk factors of DR-TB in Ethiopia. Thus, active screening of TB contacts for DR-TB might help to detect DR-TB cases as early as possible and could help to mitigate its further transmission across the community.

Drug sensitivity of clinical isolates of Mycobacterium tuberculosis and its association with bacterial genotype in the Somali region, Eastern Ethiopia

Background

Drug resistance is becoming a major bottleneck for tuberculosis (TB) control programs in countries with high TB burdens. Although several studies were conducted on the drug sensitivity of Mycobacterium tuberculosis (M. tuberculosis) in central Ethiopia, there is a lack of data on the drug sensitivity of M. tuberculosis in the peripheral regions of the country including in the Somali region. Therefore, the objective of this study was to evaluate the drug sensitivity of M. tuberculosis and its association with bacterial genotype and evaluate the performance of Xpert MTB/RIF (Xpert) in detecting resistance to rifampicin (RIF).

Methods

A total of 302 M. tuberculosis were tested using the BD BACTEC-Mycobacteria Growth Indicator Tube 960 (MGIT 960) system for their drug sensitivity to the first-line anti-TB drugs. Besides, the drug sensitivity of 10 multidrug-resistant (MDR) M. tuberculosis isolates was evaluated for the second-line anti-TB drugs. Additionally, 177 of the 302 isolates were tested for genotypic drug resistance using Xpert. Chi-square and Fisher's exact tests were used for the evaluation of the association between variables and drug sensitivity.

Results

The overall prevalence of resistance to at least one drug was 11.6% (95% CI: 7.9-15.2%), while the prevalence of MDR was 3.3% (95% CI: 1.3-5.3%). Two of the 10 MDR isolates were resistant to capreomycin. The spoligotype Shared International Type (SIT) 149 was significantly associated with either monoresistance or MDR (p < 0.05). Of the 177 isolates tested by Xpert, 6.2% (11/177) were RIF-resistant. Discordant between Xpert and MGIT 960 was observed in one isolate and linked with probe-binding delay (ΔCT max = 5.8). The sensitivity and specificity of the Xpert assay were 100 and 99.4%, respectively, while its positive and negative predictive values were 90.9 and 100%, respectively.

Conclusion

The magnitude of MDR M. tuberculosis in the Somali region of Ethiopia was higher than the national prevalence of MDR-TB warranting the strengthening of the TB control program in the Somali region. Besides, drug resistance was associated with SIT 149 spoligotype (genotype). The Xpert assay was observed to have high sensitivity and specificity in detecting RIF-resistant M. tuberculosis, which is encouraging for its application widely.

Isoniazid resistance in patients with Extrapulmonary Tuberculosis using line probe assay in a private multispecialty hospital in Bangalore, India

We aimed to study the rate of isoniazid (INH) resistance in Extrapulmonary Tuberculosis samples from a private care setting. A Line probe assay was performed on 74 culture isolates of Mycobacterium tuberculosis or directly on extrapulmonary samples received in our laboratory from 2018 to 2021. The INH mono-resistance among these extrapulmonary samples was 6.7%. (5 among 74) (95% CI: 1.04%-12.48%) Resistance to rifampicin was not detected. Increasing the availability and leveraging public private partnerships in hospitals for universal testing for INH resistance may increase detection of INH monoresistance in EP-TB and improve the strategy for TB elimination.

Drug Resistance in Children with Central Nervous System Tuberculosis from a Tertiary Care Center in Mumbai

INTRODUCTION

Central Nervous System tuberculosis (CNS-TB) is the most lethal form of extra-pulmonary TB, especially in children. In this study, we have discussed patterns of drug resistance in pediatric CNS-TB.

MATERIALS AND METHODS

Prospective observational study conducted on 100 children at a tertiary care center. Diagnosed cases of CNS-TB were enrolled. GeneXpert MTB/RIF was used upfront for diagnosis, and in cases where TB MGIT culture was positive, a phenotypic Drug Susceptibility Test (DST) was done. Patients were divided into resistant to at least one drug (DR) and drug-susceptible (DS). Various parameters were compared between these groups.

RESULTS

Mean age of participants was 5.84 ± 3.5 years, with a male-to-female ratio of 1.08 : 1; 14% of children had drug-resistant CNS TB (DR-CNS-TB). A higher proportion of children previously treated for TB were associated with drug resistance (p = 0.009), and those with disseminated TB also had a higher drug resistance (p = 0.002). Apart from this, the DR and DS groups had no statistically significant differences in demographic, clinical or epidemiological parameters.

CONCLUSIONS

Previous history of being treated for TB and disseminated TB was an independent risk factor for DR-CNS-TB. Ensuring proper adherence and compliance to anti-tubercular treatment could help in preventing the emergence of DR TB.

Drug resistance and its risk factors among extrapulmonary tuberculosis in Ethiopia: A systematic review and meta-analysis

Background

Drug-resistant tuberculosis and extrapulmonary tuberculosis are the world major public health issues. Although some primary studies have been reported on the burden of drug-resistant tuberculosis in extrapulmonary tuberculosis patients in Ethiopia, there is no systematic review and meta-analysis that attempt to summarize the available literature. Thus, we aimed to estimates the prevalence of drug-resistance in extrapulmonary tuberculosis patients and summarize the risk factors associated with the occurrence of extrapulmonary tuberculosis in Ethiopia.

Methods

We conducted a systematic review of the published primary studies on extrapulmonary drug-resistant tuberculosis in Ethiopia.

Results

Eight observational studies were included in this review from different regions of Ethiopia. The overall pooled prevalence of rifampicin resistance was 6% (95% CI 0.03–0.10), while isoniazid resistance was 7% (95% CI 0.03–0.12). The pooled prevalence of multidrug-resistant tuberculosis was 4% (95% CI 0.01–0.07). Previous tuberculosis treatment history and male gender are frequently reported risk factors for developing drug-resistant tuberculosis in extrapulmonary tuberculosis patients.

Conclusion

The current review has identified a high proportion of resistance to rifampicin, isoniazid, and multidrug-resistant tuberculosis in patients with extrapulmonary tuberculosis in Ethiopia. Clinicians should request drug susceptibility testing for all patients with presumptive extrapulmonary tuberculosis to detect drug-resistance.

Extrapulmonary Tuberculosis—An Update on the Diagnosis, Treatment and Drug Resistance

Pathogenic Mycobacterium tuberculosis complex organisms (MTBC) primarily cause pulmonary tuberculosis (PTB); however, MTBC are also capable of causing disease in extrapulmonary (EP) organs, which pose a significant threat to human health worldwide. Extrapulmonary tuberculosis (EPTB) accounts for about 20–30% of all active TB cases and affects mainly children and adults with compromised immune systems. EPTB can occur through hematogenous, lymphatic, or localized bacillary dissemination from a primary source, such as PTB, and affects the brain, eye, mouth, tongue, lymph nodes of neck, spine, bones, muscles, skin, pleura, pericardium, gastrointestinal, peritoneum, and the genitourinary system as primary and/or disseminated disease. EPTB diagnosis involves clinical, radiological, microbiological, histopathological, biochemical/immunological, and molecular methods. However, only culture and molecular techniques are considered confirmatory to differentiate MTBC from any non-tuberculous mycobacteria (NTM) species. While EPTB due to MTBC responds to first-line anti-TB drugs (ATD), drug susceptibility profiling is an essential criterion for addressing drug-resistant EPTB cases (DR-EPTB). Besides antibiotics, adjuvant therapy with corticosteroids has also been used to treat specific EPTB cases. Occasionally, surgical intervention is recommended, mainly when organ damage is debilitating to the patient. Recent epidemiological studies show a striking increase in DR-EPTB cases ranging from 10–15% across various reports. As a neglected disease, significant developments in rapid and accurate diagnosis and better therapeutic interventions are urgently needed to control the emerging EPTB situation globally. In this review, we discuss the recent advances in the clinical diagnosis, treatment, and drug resistance of EPTB.

Prevalence of Multi-Drug Resistant Mycobacterium tuberculosis in Khyber Pakhtunkhwa - A High Tuberculosis Endemic Area of Pakistan

Anti-tuberculosis therapy involves the combination of drugs to hamper the growth of Mycobacterium tuberculosis (MTB). The emergence of multidrug-resistant tuberculosis (MDR-TB) is a global concern. Pakistan has been ranked 5^th position in terms of a high burden of MDR-TB in the world. The aim of the current study was to investigate the prevalence of drug resistance in MTB in Khyber Pakhtunkhwa. Random samples were collected from 25 districts using the simple random sampling formula. All samples were processed in a biosafety level 3 laboratory for culture and drug susceptibility testing. Among 5759 presumptive tuberculosis (TB) cases, 1969 (34%) were positive. The proportion of TB was higher in females (39%) than males (29%), thus it represents a significant association between gender and tuberculosis (p < 0.05). People ages between 25 to 34 years were more likely to be infected with MTB (40%). Drug-resistant profile showed 97 (4.9%) patients were infected with MDR-TB. Streptomycin resistance was the highest and was observed in 173 (9%) isolates followed by isoniazid in 119 (6%) isolates. The lowest resistance was observed to pyrazinamide (3%). The prevalence of MDR-TB (10.4%) among patients that previously received anti-tuberculosis treatment is seemingly high. A large-scale drug resistance survey is required to evaluate the drug resistance for better management of tuberculosis.

Trends in the Prevalence and Antibiotic Resistance of Non-tuberculous Mycobacteria in Mainland China, 2000-2019: Systematic Review and Meta-Analysis

Background: China is a high-burden country of tuberculosis. The proportion of diseases caused by non-tuberculous mycobacteria (NTM) has increased, seriously affecting the prevention, control, and management of tuberculosis (TB) and posing a significant threat to human health. However, there is a lack of an organized monitoring system for NTM such as that used for tuberculosis. Comprehensive data on patient susceptibility, dominant species, and drug resistance profiles are needed to improve the treatment protocols and the management of NTM. Methods: Primary research reports of NTM clinical specimens from mainland China published between January 1, 2000 and May 31, 2019 were retrieved from four online resources (BIOSIS, Embase, PubMed, and Web of Science) and three Chinese medical literature databases (CNKI, Wanfang, and Vip) as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Results: In total, 339 publications were included in the systematic review, 129 were used in the drug susceptibility analysis, and 95 were used in the meta-analysis. Traditional culture using Lowenstein-Jensen slants combined with P-nitrobenzene acid and thiophene-2-carboxylic acid hydrazine differential medium and proportional method was most commonly used for the isolation, identification, and drug susceptibility testing of NTM in China. The crude isolation rate for NTM among TB suspected cases was 4.66-5.78%, while the proportion of NTM among Mycobacterium isolates was 11.57%. Mycobacterium abscessus and Mycobacterium avium complex were the most common clinical NTM species. NTM only showed general sensitivity to ethambutol, linezolid, clofazimine, amikacin, tobramycin, and clarithromycin. Conclusions: The prevalence of NTM in China has shown a decreasing trend. M. abscessus was replaced as the dominant species by Mycobacterium intracellulare over the course of the study. The geographic diversity of different species showed the effects of environmental and economic factors on the distribution of NTM and indicated that there were important factors still not identified. While there were only a limited number of antibiotics to which NTM showed any sensitivity, the drug resistance profiles of the isolates were highly variable and thus more caution should be taken when empirically treating NTM infection.

Epidemiology and risk factors associated with NTM pulmonary and extrapulmonary infections in a high tuberculosis endemic Region

Introduction

Non-tuberculous mycobacteria, although identified as pathogenic to humans long time ago, are emerging as the new threat in the past two decades. Even in tuberculosis endemic country such as India, they are being isolated from the clinical specimens more often than previously. This change in trend is of concern, because they are often misdiagnosed as Mycobacterium tuberculosis or even as drug-resistant tuberculosis.

Objectives

A prospective, observational study was planned to identify the frequency and risk factors associated with pulmonary and extrapulmonary non-tuberculous mycobacterial (NTM) infections. Agreement between two commercially available molecular systems, namely GenoType Mycobacteria CM assay and matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF MS) used in the identification of mycobacterial species is also analysed.

Materials and Methods

NTM isolated from pulmonary and extrapulmonary clinical specimens over a period of 1½ year was included in the study. Patient demographics were collected, and the risk factors associated with NTM infections were analyzed. NTM grown on culture was speciated using GenoType Mycobacteria CM assay (HAIN Life Sciences, Germany) and MALDI TOF MS (bioMerieux, France). Drug-susceptibility tests were done for rapid-growing NTM using E-test (bioMerieux, France).

Results

Eight hundred and fifty-four mycobacteria were isolated from 5009 specimens processed during the study period. Out of the mycobacteria grown, 74 (8.7%) were NTM and 780 (91.3%) were Mycobacterium tuberculosis complex. The NTM isolated from pulmonary specimens were 46 (62.16%) and from extrapulmonary sources were 28 (37.84%). The most common species isolated from pulmonary specimens was Mycobacterium intracellulare and from extrapulmonary specimens was Mycobacterium abscessus. Concordance between the two commercial assays used for the identification was 96.49%. The most common risk factor associated with pulmonary NTM was previous lung pathology, while with extrapulmonary NTM infection was previous surgical intervention. Drug-susceptibility tests for rapid growers showed amikacin and clarithromycin as the most active drugs in vitro.

Conclusions

NTM plays a significant role in causing pulmonary and extrapulmonary infections even in our part of the country with high endemicity of tuberculosis. NTM has emerged as important pathogens even in the immunocompetent patients. There is a need for rapid diagnosis and susceptibility testing of NTM to aid physicians administer timely and appropriate treatment to the patients.

Ribosomal maturation factor (RimP) is essential for survival of nontuberculous mycobacteria Mycobacterium fortuitum under in vitro acidic stress conditions

Mycobacterium fortuitum is an important human pathogenic NTM, which resists stress conditions inside macrophages by exploitation of specific genes. TnphoA-based transposon mutagenesis was employed to identify membrane genes responsible for survival of M. fortuitum under such stress conditions. A library of about 450 mutants was constructed after electroporation of vector pRT291 into wild-type M. fortuitum. On the basis of blue color development and alkaline phosphatase assay, 20 mutants were shortlisted to screen for growth and survival under acidic stress at pH 6.5, 5.5, 4.5, and 3.5. Mutant MT727 showed reduced growth and survival under acidic stress. The acid susceptible mutant MT727 was subjected to other in vitro stress conditions prevalent inside macrophages including oxidative, nutrient starvation and nitrosative stress. However, the mutant showed no appreciable difference in growth behavior under oxidative, nutrient starvation and nitrosative stress conditions in comparison to the wild type. Genomic and bioinformatics analysis of MT727 led to identification of putative ribosomal maturation factor RimP of M. fortuitum to be affected by mutagenesis, showing closest homology to M. abscessus RimP. In silico functional interaction of RimP protein using STRING database showed its interaction with proteins of ribosomal assembly and maturation. Results indicate role of rimP gene in survival of M. fortuitum under acidic stress conditions which may be further explored for use as a potential drug target against M. fortuitum and other mycobacterial infections.

Extrapulmonary drug-resistant tuberculosis at a drug-resistant tuberculosis center, Mumbai: Our experience - Hope in the midst of despair!

BACKGROUND

Drug-resistant tuberculosis (DR-TB) is a global problem with only 52% reported cure rate. Extrapulmonary (EP) DR-TB poses a formidable diagnostic, therapeutic challenge. We aimed to study their clinical profile and treatment outcomes under the programmatic setting.

MATERIALS AND METHODS

This retrospective observational study included the database of consecutive EPDR-TB cases enrolled at the DR-TB center from 2012 to 2014. The demographic, clinical details, drug susceptibility tests (DSTs), follow-up, therapy, adverse events (AEs), and outcome were reviewed. Statistical analysis was done using percentages and mean.

RESULTS

Of total 1743 DR-TB patients, 76 (4.4%) EPDR-TB cases were included. These consisted of 53 (69.7%) adults and 23 (30.3%) children, with female preponderance. The mean age in adults and children was 27.96 (9.63) and 12.56 (3.83), respectively. EP sites involved were lymph nodes in 39 (51.3%), spine in 15 (19.7%), other bones in 6 (7.9%), pleural effusion in 9 (11.9%), central nervous system in 2 (2.6%), and disseminated EP disease in 5 (6.6%). Forty-one (53.9%) had multi-DR-TB (MDR-TB), 29 (38.2%) MDR-TB with fluoroquinolone resistance {preextensively DR-TB (Pre-XDR-TB (FQ)), 1 (1.3%) MDR-TB with aminoglycoside resistance (Pre-XDR-TB (AM)), and 5 (6.6%) extensively DR-TB (XDR-TB) on DST. Thirteen (17.11%) had comorbidities. None had HIV. Two (2.63%) had DM. Patients were treated as per the revised TB control program - programmatic management of DR-TB guidelines. Duration of intensive (IP) was 6.55 (1.22) months. Ten (13.2%) received shorter regimens, wherein therapy was stopped at 12-18 months due to severe adverse drug reactions and treatment response. Sixty-two (81.6%) completed treatment, 8 (10.5%) defaulted, 3 (4%) died, 2 (2.6%) failed, and 1 (1.3%) was transferred out. Two-third of patients reported AE.

CONCLUSION

The prevalence of EP cases in DR-TB was 4.4%. Treatment completion rate was very high (81.6%). Shorter regimens were efficacious.

Prevalence and risk factors of drug-resistant extrapulmonary tuberculosis

BACKGROUND

Physicians are usually aware of the occurrence of drug-resistant (DR) pulmonary tuberculosis (PTB), but lack concern about DR-extrapulmonary TB (EPTB). Data regarding the prevalence and risk factors of DR-EPTB remain limited.

OBJECTIVES

To determine the prevalence and risk factors of DR-EPTB.

METHODS

A retrospective study was performed in patients who had culture-proven Mycobacterium tuberculosis (MTB) from various specimens between January 2013 and December 2015. Patients were classified into three groups: PTB, EPTB and concomitant PTB and EPTB (PTB + EPTB). Clinical data, chest radiographic extent of disease and patterns of DR were collected.

RESULTS

There were 1014 culture-proven MTB specimens (716 pulmonary specimens and 298 extrapulmonary specimens) from 986 patients (648 PTB, 218 EPTB and 120 PTB + EPTB). The prevalences of isoniazid-, rifampicin- and multidrug-resistant EPTB were 7.8%, .5% and .5%, respectively, which were lower than those of PTB. When PTB and EPTB coexisted, a higher rate of DR-TB was observed than for PTB alone. Of 338 EPTB patients, the extent of radiographic disease was associated with isoniazid-, rifampicin- and multidrug-resistant TB. Previous history of TB and use of steroids/immunosuppressive drugs were also associated with rifampicin- and multidrug-resistant TB in multivariate analysis.

CONCLUSIONS

The prevalence of DR-EPTB was high in patients who had concomitant PTB. Although the prevalences of rifampicin- and multidrug-resistant TB were low in isolated EPTB, the prevalence of isoniazid-resistant TB remained high. Therefore, drug susceptibility testing should be performed in EPTB patients, especially those who carry the aforementioned risk factors.

Utility of multiplex real-time PCR in the diagnosis of extrapulmonary tuberculosis

Objective

The diagnosis of extrapulmonary tuberculosis is still a challenge because of its pauci-bacillary nature. The aim of the study was to evaluate the role of a multiplex PCR assay in the diagnosis of extrapulmonary tuberculosis and to compare the efficiency of two targets, IS6110 and MPB64 to detect Mycobacterium tuberculosis.

Methods

150 extrapulmonary samples (61 pus/aspirate, 46 tissue, 32 body fluids, and 11 urine) from clinically suspected cases of tuberculosis were included in the study. All the samples were subjected to direct fluorescent microscopy, TB culture (BacT/ALERT 3D, biomerieux, Durham, North Carolina, USA) and a Multiplexed Tandem PCR targeting two mycobacterial DNA sequences, IS6110 and MPB64. Master-Mix reagents and primers were prepared by AusDiagnostics Pvt. Ltd (Alexandria, New South Wales, Australia). The performance of the assay was assessed using a composite gold standard, which included clinical characteristics, microbiology smear as well as culture, histopathology, cytology, radiology, and response to antitubercular therapy.

Results

20.3%, 23.6%, and 45.3% of specimens were positive by smear, culture, and PCR, respectively. The sensitivity and specificity of the multiplex PCR was 91.9% and 88.4%, respectively, using the composite gold standard. Positive and negative predictive values of the PCR were estimated as 85.1% and 93.8%, respectively. Higher positivity was observed with target IS6110 (44.6%) as compared to target MPB64 (18.9%). The sensitivities of IS6110 and MPB64 individual targets were 90.3% and 64.5%, respectively, and specificities were 88.4% and 97.7%, respectively.

Conclusion

PCR can play an important role in rapid and accurate diagnosis of extrapulmonary tuberculosis. IS6110 alone is an effective target in our part of the country.