First-line Drug Resistance Research Articles

Rifampicin resistant Mycobacterium tuberculosis in Vietnam, 2020–2022

ObjectiveWe conducted a descriptive analysis of multi-drug resistant tuberculosis (MDR-TB) in Vietnam’s two largest cities, Hanoi and Ho Chi Minh city. MethodsAll patients with rifampicin resistant tuberculosis were recruited from Hanoi and surrounding provinces between 2020 and 2022. Additional patients were recruited from Ho Chi Minh city over the same time period. Demographic data were recorded from all patients, and samples collected, cultured, whole genome sequenced and analysed for drug resistance mutations. Genomic susceptibility predictions were made on the basis of the World Health Organization’s catalogue of mutations in Mycobacterium tuberculosis associated with drug resistance, version 2. Comparisons were made against phenotypic drug susceptibility test results where these were available. Multivariable logistic regression was used to assess risk factors for previous episodes of tuberculosis. Results233/265 sequenced isolates were of sufficient quality for analysis, 146 (63 %) from Ho Chi Minh City and 87 (37 %) from Hanoi. 198 (85 %) were lineage 2, 20 (9 %) were lineage 4, and 15 (6 %) were lineage 1. 17/211 (8 %) for whom HIV status was known were infected, and 109/214 (51 %) patients had had a previous episode of tuberculosis. The main risk factor for a previous episode was HIV infection (odds ratio 5.1 (95 % confidence interval 1.3–20.0); p = 0.021). Sensitivity for predicting first-line drug resistance from whole genome sequencing data was over 90 %, with the exception of pyrazinamide (85 %). For moxifloxacin and amikacin it was 50 % or less. Among rifampicin-resistant isolates, prevalence of resistance to each non-first-line drug was < 20 %. ConclusionsDrug resistance among most MDR-TB strains in Vietnam’s two largest cities is confined largely to first-line drugs. Living with HIV is the main risk factor among patients with MDR-TB for having had a previous episode of tuberculosis.

ATRX is a predictive marker for endocrinotherapy and chemotherapy resistance in HER2-/HR+ breast cancer through the regulation of the AR, GLI3 and GATA2 transcriptional network.

Drug resistance in breast cancer (BC) is a clinical challenge. Exploring the mechanism and identifying a precise predictive biomarker for the drug resistance in BC is critical. Three first-line drug (paclitaxel, doxorubicin and tamoxifen) resistance datasets in BC from GEO were merged to obtain 1,461 differentially expressed genes for weighted correlation network analysis, resulting in identifying ATRX as the hub gene. ATRX is a chromatin remodelling protein, therefore, ATRX-associated transcription factors were explored, thereby identifying the network of AR, GLI3 and GATA2. GO and KEGG analyses revealed immunity, transcriptional regulation and endocrinotherapy/chemotherapy resistance were enriched. Moreover, CIBERSORT revealed immunity regulation was inhibited in the resistance group. ssGSEA showed a significantly lower immune status in the ATRX-Low group compared to the ATRX-High group. Furthermore, the peaks of H3K9me3 ChIP-seq on the four genes were higher in normal tissues than in BC tissues. Notably, the frequency of ATRX mutation was higher than BRCA in BC. Moreover, depressed ATRX revealed worse overall survival and disease-free survival in the human epidermal growth factor receptor 2 (HER2)-/hormone receptor (HR)+ BC. Additionally, depressed ATRX predicted poor results for patients who underwent endocrinotherapy or chemotherapy in the HER2-/HR+ BC subgroup. A nomogram based on ATRX, TILs and ER exhibited a significantly accurate survival prediction ability. Importantly, overexpression of ATRX significantly inhibited the IC50 of the three first-line drugs on MCF-7 cell. Thus, ATRX is an efficient predictive biomarker for endocrinotherapy and chemotherapy resistance in HER2-/HR+ BC and acts by suppressing the AR, GLI3 and GATA2 transcriptional network.

Monitoring of First-line Drug Resistance Mutations Outside the Scope of Xpert MTB/RIF Ultra is Needed for Successful Control of DR-TB in Southern Mozambique.

Multidrug-resistant(MDR) tuberculosis in Southern Africa is of great concern, exacerbated by the spread of a clone harboring a mutation missed by Xpert Ultra. In Southern Mozambique, the presence of such mutation and rising cases of non-MDR isoniazid resistance highlights the need to ensure accurate detection of antimicrobial-resistance in the country.

Resistance Profiles to Second-Line Anti-Tuberculosis Drugs and Their Treatment Outcomes: A Three-Year Retrospective Analysis from South India.

Background: Patients with first-line drug resistance (DR) to rifampicin (RIF) or isoniazid (INH) as a first-line (FL) line probe assay (LPA) were subjected to genotypic DST using second-line (SL) LPA to identify SL-DR (including pre-XDR) under the National TB Elimination Program (NTEP), India. SL-DR patients were initiated on different DR-TB treatment regimens and monitored for their outcomes. The objective of this retrospective analysis was to understand the mutation profile and treatment outcomes of SL-DR patients. Materials and Methods: A retrospective analysis of mutation profile, treatment regimen, and treatment outcome was performed for SL-DR patients who were tested at ICMR-NIRT, Supra-National Reference Laboratory, Chennai between the years 2018 and 2020. All information, including patient demographics and treatment outcomes, was extracted from the NTEP Ni-kshay database. Results: Between 2018 and 2020, 217 patients out of 2557 samples tested were identified with SL-DR by SL-LPA. Among them, 158/217 were FQ-resistant, 34/217 were SLID-resistant, and 25/217 were resistant to both. D94G (Mut3C) of gyrA and a1401g of rrs were the most predominant mutations in the FQ and SLID resistance types, respectively. Favorable (cured and treatment complete) and unfavorable outcomes (died, lost to follow up, treatment failed, and treatment regimen changed) were recorded in a total of 82/217 and 68/217 patients in the NTEP Ni-kshay database. Conclusions: As per the testing algorithm, SL- LPA is used for genotypic DST following identification of first-line resistance, for early detection of SL-DR in India. The fluoroquinolone resistance pattern seen in this study population corelates with the global trend. Early detection of fluoroquinolone resistance and monitoring of treatment outcome can help achieve better patient management.

Use of laboratory-developed assays in global HIV-1 treatment-monitoring and research

There has been a surge in the emergence of HIV-1 drug resistance in Low and Middle-Income Countries (LMICs) due to poor drug-adherence and limited access to viral load testing, the current standard for treatment-monitoring. It is estimated that only 75% of people living with HIV (PLWH) worldwide have access to viral load testing. In LMICs, this figure is below 50%. In a recent WHO survey in mostly LMICs, 21 out of 30 countries surveyed found HIV-1 first-line pre-treatment drug resistance in over 10% of study participants. In the worst-affected regions, up to 68% of infants born to HIV-1 positive mothers were found to harbour first-line HIV-1 treatment resistance. This is a huge public health concern. Greater access to treatment-monitoring is required in LMICs if the UNAIDS “third 95” targets are to be achieved by 2030. Here, we review the current challenges of viral load testing and present the case for greater utilization of Laboratory-based assays that quantify intracellular HIV-1 RNA and/or DNA to provide broader worldwide access to HIV-1 surveillance, drug-resistance monitoring, and cure-research.

MTBDRplus and MTBDRsl for simultaneous diagnosis of gastrointestinal tuberculosis and detection of first-line and second-line drug resistance.

Emergence of drug resistance, especially to second-line drugs, hampers tuberculosis elimination efforts. The present study aimed to evaluate MTBDRplus and MTBDRsl assays for detecting first-line and second-line drug resistance, respectively, in gastrointestinal tuberculosis (GITB). Thirty ileocecal biopsy specimens, processed in the Department of Microbiology between 2012 and 2022, that showed growth of Mycobacterium tuberculosis on culture were included in the study. DNA, extracted from culture, was subjected to MTBDRplus and MTBDRsl (Hain Lifescience GmbH, Nehren, Germany), following manufacturer's instructions. Their performance was compared against phenotypic drug susceptibility testing (pDST) and gene sequencing. Out of the 30 specimens, 4 (13.33%) were mono-isoniazid resistant, 4 (13.33%) were multidrug resistant (MDR), 2 (6.67%) were pre-extensively drug resistant (pre-XDR), and 2 (6.67%) were mono-fluoroquinolone resistant. The results were 100% concordant with pDST and gene sequencing. In the wake of growing drug resistance in all forms of extrapulmonary tuberculosis, including GITB, MTBDRplus and MTBDRsl are reliable tools for screening of resistance to both first-line and second-line drugs.

Limited Impact of First-Line Drug Resistance Mutations on Virologic Response Among Patients Receiving Second-Line Antiretroviral Therapy in Rural Uganda.

Delayed detection of ART failure in settings without access to viral load (VL) monitoring has been hypothesized to lead to suboptimal response to second-line therapy due to accumulated drug resistance mutations (DRMs). We tested this hypothesis in a program setting in rural Uganda. From June 2012 to January 2014, we enrolled participants receiving nonnucleoside reverse transcriptase inhibitor-based first-line ART for ≥4 years, without access to VL monitoring. Participants who had a measured VL ≥ 1000 copies/mL on two occasions were switched to protease inhibitor-based regimens and followed every 6 months until September 2016. We measured VL at study exit. We conducted DRM testing at enrollment and study exit and examined factors associated with virologic failure. We enrolled 137 participants (64.3% female) with a median age of 44 years and a median duration on ART of 6.0 years. In a median of 2.8 years of follow-up, 7 (5%) died, 5 (3.6%) voluntarily withdrew, and 9 (6.6%) became lost to follow-up. Of 116 participants with a VL result at study exit, 20 (17%) had VL > 1000 copies/mL. Virologic failure was associated with reporting suboptimal adherence ( P = 0.028). Of patients with DRM data at enrollment, 103 of 105 (98%) had at least 1 DRM. Participants with thymidine analog mutations at enrollment were less likely to have virologic failure at study exit (11% vs. 36%; P = 0.007). No other DRMs were associated with failure. Even in the presence of multiple DRMs on first-line therapy, virologic failure after 3 years of protease inhibitor-based ART was infrequent. Suboptimal adherence to ART was associated with virologic failure.

Evaluation Study of xMAP TIER Assay on a Microsphere-Based Platform for Detecting First-Line Anti-Tuberculosis Drug Resistance

Early diagnosis of drug susceptibility for tuberculosis (TB) patients could guide the timely initiation of effective treatment. We evaluated a novel multiplex xMAP TIER (Tuberculosis-Isoniazid-Ethambutol-Rifampicin) assay based on the Luminex xMAP system to detect first-line anti-tuberculous drug resistance. Deoxyribonucleic acid samples from 353 Mycobacterium tuberculosis clinical isolates were amplified by multiplex polymerase chain reaction, followed by hybridization and analysis through the xMAP system. Compared with the broth microdilution method, the sensitivity and specificity of the xMAP TIER assay for detecting resistance was 94.9% (95%CI, 90.0-99.8%) and 98.9% (95%CI, 97.7-100.0%) for rifampicin; 89.1% (95%CI, 83.9-94.3%) and 100.0% (95%CI, 100.0-100.0%) for isoniazid; 82.1% (95% CI, 68.0-96.3%) and 99.7% (95% CI, 99.0-100.0%) for ethambutol. With DNA sequencing as the reference standard, the sensitivity and specificity of xMAP TIER for detecting resistance were 95.0% (95% CI, 90.2-99.8%) and 99.6% (95% CI, 98.9-100.0%) for rifampicin; 96.9% (95% CI, 93.8-99.9%) and 100.0% (95% CI, 100.0-100.0%) for isoniazid; 86.1% (95% CI, 74.8-97.4%) and 100.0% (95% CI, 100.0-100.0%) for ethambutol. The results achieved showed that the xMAP TIER assay had good performance for detecting first-line anti-tuberculosis drug resistance, and it has the potential to diagnose drug-resistant tuberculosis more accurately due to the addition of more optimal design primers and probes on open architecture xMAP system.

Prevalence and genetic basis of first-line drug resistance of Mycobacterium tuberculosis in Ca Mau, Vietnam.

Background and objectiveData on the prevalence of anti-tuberculous drug resistance and its association with genetic mutations in Mycobacterium tuberculosis are limited. Our study explores the genomics of tuberculosis in Ca Mau, Vietnam.MethodsPatients ≥15 years in Ca Mau Province, Vietnam, were screened annually for tuberculosis between 2014 and 2017. Isolates underwent drug susceptibility testing (DST) using the breakpoint method. DNA was extracted and whole genome sequencing (WGS) was performed.ResultsWe identified 365 positive sputum cultures for M. tuberculosis and processed 237 for DST and 265 for WGS. Resistance to isoniazid was present in 19.8% (95% CI 14.7 to 24.9%), rifampicin in 3.5% (1.1 to 5.7%) and ethambutol in 2.5% (0.9 to 5.4%) of isolates. Relevant mutations in rpoB gene were detected in 3.8% (1.8 to 6.8%). katG, inhA or fabG1 mutations were found in 19.6% (15.0 to 24.9%) with KatG being most common at 12.8% (9.1–17.5%). We found 38.4% of isolates were of Beijing lineage, 49.4% East-African-Indian lineage and 8.4% European-American lineage. There were no associations between resistance profiles and clinical features.ConclusionThe high burden of isoniazid resistance and the katG mutation highlights the challenges facing Vietnam in its efforts to achieve its EndTB goals.

PEtOxylated Interferon-α2a Bioconjugates Addressing H1N1 Influenza A Virus Infection.

Influenza A viruses (IAV), including the pandemic 2009 (pdm09) H1N1 or avian influenza H5N1 virus, may advance into more pathogenic, potentially antiviral drug-resistant strains (including loss of susceptibility against oseltamivir). Such IAV strains fuel the risk of future global outbreaks, to which this study responds by re-engineering Interferon-α2a (IFN-α2a) bioconjugates into influenza therapeutics. Type-I interferons such as IFN-α2a play an essential role in influenza infection and may prevent serious disease courses. We site-specifically conjugated a genetically engineered IFN-α2a mutant to poly(2-ethyl-2-oxazoline)s (PEtOx) of different molecular weights by strain-promoted azide-alkyne cyclo-addition. The promising pharmacokinetic profile of the 25 kDa PEtOx bioconjugate in mice echoed an efficacy in IAV-infected ferrets. One intraperitoneal administration of this bioconjugate, but not the marketed IFN-α2a bioconjugate, changed the disease course similar to oseltamivir, given orally twice every study day. PEtOxylated IFN-α2a bioconjugates may expand our therapeutic arsenal against future influenza pandemics, particularly in light of rising first-line antiviral drug resistance to IAV.

First-line drug resistance of Mycobacterium tuberculosis strains in Sub-Saharan Africa

&lt;p&gt;Throughout history, natural products have been utilized to treat a variety of diseases; cinchona tree containing quinine to treat malaria, penicillin for the treatment of infectious diseases, and a wide variety of others. Since the discovery of penicillin by Fleming in 1929, a large number of antibacterial agents have been developed and have had a huge impact on human health. However, due to widespread excessive dispensing of antibiotics, certain bacterial pathogens have developed resistant strains via various mutations in their genomic setup. One of such pathogens is &lt;em&gt;Mycobacterium tuberculosis&lt;/em&gt;, hence the study. This study aims at describing the epidemiology of resistant strains of &lt;em&gt;Mycobacterium tuberculosis&lt;/em&gt;, its risk factors and potential control strategies in Sub-Saharan Africa. PubMed, BMC and other reliable databases were searched for English research articles published from January 2015 to December 2020 reporting on the molecular epidemiology of &lt;em&gt;Mycobacterium tuberculosis&lt;/em&gt;. Due to lack of credible data from all Sub-Saharan African countries and first-line drugs, the study was streamlined to the most populous countries in Sub-Saharan Africa, 17 of which were considered in this study, and the two most common first-line drugs (i.e., Rifampicin and Isoniazid). A total of 54 research articles were thoroughly reviewed for the final analysis. Isoniazid had higher monoresistance (8.5%) than Rifampicin (3.6%). Tuberculosis (TB) Monoresistance was highest in Morocco (54%) and lowest in Mali (4.2%), while multidrug resistance highest in Senegal (58.1%), and lowest in Cameroon (1.1%).&lt;/p&gt;

Paradoxical development of pleural-based masses in patients with pleural tuberculosis during treatment: a clinical observational study in China

BackgroundTo explored the clinical, pathological, and bacteriological characteristics of pleural-based masses occurred during anti-tuberculosis (TB) treatment in patients with pleural TB.MethodsPatients referred with newly diagnosed pleural TB were prospectively enrolled into the study. Patients were followed up throughout the treatment, and clinical data were recorded. Percutaneous biopsy and surgical tissues from pleural-based masses were examined histologically and samples sent for PCR. Cytokines in the pleural effusions and clinical factors were collected and compared between different patients.ResultsA total of 122 patients with pleural TB were enrolled, and 34.4% (42/122) displayed newly observed pleural-based mass during the treatment. Twelve cases underwent surgical resection at the 12 ± 0.5 months during the treatment course. Based on the surgical observation, 58.3% (7 /12) were located in pleura, 41.7% (5/12) were located in the lung parenchyma. Pathological observations showed that the pleural-based masses were typed as granulomatous inflammation, fibrous hyperplasia and necrosis. Mycobacterium tuberculosis PCR was positive in 57.1% of the cases (24/42). Any first-line anti-TB drug resistance gene mutations were positive in only 9.5% (4/42). Aside from 12 cases who underwent the surgical operation, 86.7% of the patients (26/30) still had a pleural-based mass at the end of 12 months treatment course. Patients with a pleural-based mass were younger, had a thicker pleural, a higher proportion of pleural adhesive, loculated pleural effusion and residual pleural effusion, and a higher level of LDH, ADA and lower glucose in pleural effusion than those without a pleural-based mass occurrence during the treatment (all Pcorr < 0.05).ConclusionsPleural-based masses were observed in about one-third of patients with pleural TB. The masses were in the lung or pleura and were divided into three pathological types.

First-Line Anti-Tuberculosis Drug Resistance Pattern

Introduction: Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis and usually attacks the lungs. Indonesia is in the third rank of TB cases in the world. An important concern regarding TB currently is the case of anti-TB drug resistance, hence research on resistance patterns and risk factors is essential. This study aimed to identify the pattern of first-line anti-TB drug resistance at Dr. Soetomo General Hospital, Surabaya.Methods: A descriptive retrospective study was conducted at Dr. Soetomo General Hospital, Surabaya for the period of 2017-2019. The samples were obtained through total population sampling of 239 pulmonary TB patients with first-line anti-TB drug resistance which were registered at MDR-TB Polyclinic Dr. Soetomo General Hospital, Surabaya. Only complete medical records were included. The variables were first-line anti-TB drug resistance (isoniazid, rifampicin, ethambutol, streptomycin) and patients’ characteristics (age, gender, treatment history, and comorbidities). The drug resistance test was performed using certified culture methods.Results: Among 239 patients, the incidences of resistance to H, R, E, and S were 79.08%, 94.14%, 25.94%, and 20.08%, respectively. The most common patterns were HR (42.26%), R (18.83%), and HRE (12.55%). The largest age group was 45-54 years old (38%). The dominant gender was male (56.49%). The most treatment history category was relapsed patients (48%) and there were more patients with comorbidity (57%).Conclusion: The highest incidence rate of resistance was rifampicin and the most common resistance pattern was HR. Most of the patients were of working age, male, relapse patients, and had comorbidities. An appropriate TB therapy treatment plays an important role in preventing resistance.

FIRST LINE ANTI-TUBERCULOSIS DRUG RESISTANCE PATTERN IN MULTIDRUG-RESISTANT PULMONARY TUBERCULOSIS PATIENTS CORRELATE WITH ACID FAST BACILLI MICROSCOPY GRADING

Multidrug-resistant tuberculosis (MDR-TB) is a global public health crisis. Acid-fast bacilli (AFB) gradation in sputum examination is an important component in Pulmonary Tuberculosis (PTB) diagnosis and treatment outcome monitoring. Previously treated pulmonary TB patients with a higher AFB smear gradation may have higher rates of acquired resistance. Patients with a higher AFB grade indicate a higher bacillary load and had higher rates of acquired resistance. This study aims to evaluate the correlation between AFB gradation and first-line anti-TB drug resistance patterns in MDR pulmonary TB patients. This was a retrospective study conducted from August 2009 to April 2018 in Dr. Soetomo Hospital. Sputum samples were taken from MDR PTB patients. Sputum smear examination was done using Ziehl–Neelsen staining and gradation was measured according to IUATLD criteria. Samples with positive smear were evaluated for resistance patterns based on culture and resistance tests using the MGIT 960 BACTEC System. There were 433 sputum samples with AFB positive collected from MDR PTB patients. Resistance to RHES was found in 22 (14%) AFB +1, 19 (15%) AFB +2, and 29 (20%) AFB +3. Resistance to RHS was found in 22 (14%) AFB +1, 12 (9%) AFB +2, and 13 (9%) AFB +3. Resistance to RHE was found in 39 (25%) AFB +1, 38 (29%) AFB +2, and 35 (24%) AFB +3. Resistance to RH was found in 74 (47%) AFB +1, 61 (47%) AFB +2, and 69 (47%) AFB +3. Statistic analysis by Spearman test showed that there was no significant correlation between AFB gradation and first-line anti-TB drug resistance patterns. Acquired resistance to RHES can also found in lower bacillary load AFB +1.

Inhibition of Mycobacterium tuberculosis tRNA-Ligases Using siRNA-Based Gene Silencing Method: A Computational Approach.

Tuberculosis (TB) is a major public health problem in several countries. Development of first-line and second-line drug resistance strains of Mycobacterium tuberculosis further complicated the management of the disease. Despite available drugs to treat TB, 1.6 million people died from the disease in 2017. In this study, we designed 10 siRNAs against 8 tRNA ligases of M. tuberculosis and validated their usefulness for inhibition of protein synthesis by using computational approach. We found that the predicted siRNAs efficiently form seed duplex complex against their respective mRNA targets. Other different computational approaches were also undertaken to assess the stability, accessibility, and strength of seed duplex complex of designed siRNA and targeted mRNA. On the basis of the computational approach, we reciprocated that the technique will help in opening a new window in the field of TB control program and could be taken for further clinical studies to find their appropriateness for TB eradication.

First-line tuberculosis drug resistance patterns and associated risk factors in Germany, 2008-2017.

BackgroundDrug-resistant tuberculosis (TB), especially multidrug-resistant TB (MDR-TB), poses a threat to public health. While standard surveillance focuses on Rifampicin and/or Isoniazid resistance, little is known about other resistance patterns. This study aims to identify predominant drug resistance (DR) patterns in Germany and risk factors associated with them in order to inform diagnostic and treatment strategies.MethodsCase-based TB surveillance data notified in Germany from 2008–2017 were utilized to investigate DR and MDR-TB patterns for Isoniazid (H), Rifampicin (R), Pyrazinamide (Z), Ethambutol (E), and Streptomycin (S). Predominant patterns were further analyzed stratified by sex, age, country of birth, prior TB, and disease site. Multivariable logistic regression was conducted to determine risk factors associated with any resistance, MDR-TB, and complete HRZES resistance.Results26,228 cases with complete DST results were included in the study, among which 3,324 cases had any DR (12.7%). Four patterns were predominant, representing about ¾ of all cases with any resistance (S: 814 [3.1%]; H: 768 [2.9%]; HS: 552 [2.1%]; Z: 412 [1.6%]). High proportions of S and H resistances were found among both German and foreign-born populations, especially those born in Eastern Europe, and were unexpectedly high among children (H: 4.3%; S: 4.6%). Foreign-born cases had significantly higher proportion of any resistance (16.0%) and MDR-TB (3.3%) compared to German-born cases (8.3% and 0.6%). Of 556 MDR-TB cases, 39.2% showed complete HRZES resistance. Logistic regression revealed having prior TB and being foreign-born as consistently strong risk factors for any DR, MDR-TB, and complete HRZES resistance.ConclusionsDR patterns observed in Germany, particularly for MDR-TB were more complex than expected, highlighting the fact that detailed drug-testing results are crucial before incorporating HRZES drugs in MDR-TB treatment. Furthermore, the relatively high rate of H-resistance in Germany provides strong rationale against the use of only H-based preventive therapy for LTBI.

What will it take to eliminate drug-resistant tuberculosis?

Drug-resistant tuberculosis (DR-TB) is challenging to diagnose, treat, and prevent, but this situation is slowly changing. If the world is to drastically reduce the incidence of DR-TB, we must stop creating new DR-TB as an essential first step. The DR-TB epidemic that is ongoing should also be directly addressed. First-line drug resistance must be rapidly detected using universal molecular testing for resistance to at least rifampin and, preferably, other key drugs at initial TB diagnosis. DR-TB treatment outcomes must also improve dramatically. Effective use of currently available, new, and repurposed drugs, combined with patient-centered treatment that aids adherence and reduces catastrophic costs, are essential. Innovations within sight, such as short, highly effective, broadly indicated regimens, paired with point-of-care drug susceptibility testing, could accelerate progress in treatment outcomes. Preventing or containing resistance to second-line and novel drugs is also critical and will require high-quality systems for diagnosis, regimen selection, and treatment monitoring. Finally, earlier detection and/or prevention of DR-TB is necessary, with particular attention to airborne infection control, case finding, and preventive therapy for contacts of patients with DR-TB. Implementing these strategies can overcome the barrier that DR-TB represents for global TB elimination efforts, and could ultimately make global elimination of DR-TB (fewer than one annual case per million population worldwide) attainable. There is a strong cost-effectiveness case to support pursuing DR-TB elimination; however, achieving this goal will require substantial global investment plus political and societal commitment at national and local levels.

Multidrug-Resistant Tuberculosis in the Democratic Republic of Congo: Analysis of Continuous Surveillance Data from 2007 to 2016

Background: For countries with limited resources such as the Democratic Republic of the Congo (DRC), the diagnosis of Multidrug-resistant tuberculosis (MDR-TB) is still insufficient. The MDR-TB identification is done primarily among at-risk groups. The knowledge of the true extent of the MDR-TB remains a major challenge. This study tries to determine the proportion of MDR-TB in each group of presumptive MDR-TB patients and to identify some associated factors. Methods: This is an analysis of the DRC surveillance between 2007 and 2016. The proportions were expressed in Percentage. The logistic regression permits to identify the associated factors with the RR-/MDR-TB with adjusted Odds-ratio and 95% CI. Significance defined as p ≤ 0.05. Results: Overall, 83% (5407/6512) of the MDR-TB presumptive cases had each a TB test. 86.5% (4676/5407) had each a culture and drug sensitive testing (DST) on solid medium, and 24.3% (1312/5407) had performed an Xpert MTB/RIF test. The proportion of those with at least one first-line drug resistance was 59.3% [95% CI 57.2 - 61.4] among which 50.1%, [95% CI 47.9 - 52.3] for the isoniazid, 45.6% [95% CI 43.4 - 47.8] for the rifampicin, 49.9% [95% CI 47.8 - 52.1] for ethambutol and 35.8% [95% CI 33.7 - 37.9] for streptomycin. The confirmation of MDR-TB was 42.8% [95% CI 38.4 - 47.8]. Combining both tests, the proportion of RR-/MDR-TB was 49.6% [95% CI 47.9 - 51.4] for all presumptives. This proportion was 60.0% for failures, 40.7% for relapses and 34.7% for defaulters. Associated factors with the diagnosis of MDR-TB were: aged less than 35 years; prior treatment failure; defaulters; the delay between the collection of sputum and the test completion. Conclusion: The proportion of RR-/MDR-TB among the presumptives has been higher than those estimated generally. The National tuberculosis programme (NTP) should improve patient follow-up to reduce TB treatment failures and defaulting. Moreover, while increasing the use of molecular tests, they should reduce sample delivery times when they use culture and DST concomitantly.

Role of MIRU-VNTR and spoligotyping in assessing the genetic diversity of Mycobacterium tuberculosis in Henan Province, China

BackgroundTuberculosis remains a serious threat to human health as an infectious disease in China. Henan, a most populated province in China, has a high incidence of tuberculosis (TB). Though the genetic diversity of Mycobacterium tuberculosis (MTB) has been investigated in many regions, there have been only a few studies on the molecular characteristics and drug resistance phenotypes in Henan. This is the first study on the genetic profile of MTB from Henan.MethodsA total of 668 MTB isolates from various areas were genotyped with spoligotyping and 26-locus MIRU-VNTR (classical 24-locus MIRU-VNTR and 2 other loci). The association between TB spoligotype signatures and drug-resistant profiles was analysed.ResultsOur data revealed that MTB isolates circulating in Henan had a high degree of genetic variation. The Beijing family was the most predominant genotype (83.53%,n = 558), and the typical Beijing type(ST1) was the major sublineage (81.73%,n = 546). In total,668 isolates were divided into 567 different types, forming 38 clusters (2–15 isolates per cluster), and 529 unique types by 26-locus MIRU-VNTR analysis. There was no correlation between the Beijing family and gender, age at diagnosis or treatment history, whereas the Beijing family was significantly associated with all four first-line drug resistance and multidrug-resistant phenotypes. For these samples, 15 of 26 MIRU-VNTR loci had high or moderate discriminatory power according to the Hunter-Gaston discriminatory index. A combination of the 10 most polymorphic loci had similar discriminatory power as the 26-locus set.ConclusionThe Beijing genotype is the most prevalent family. Ten-locus MIRU-VNTR in combination with spoligotyping can efficiently classify the molecular type of MTB in Henan Province.

Surveillance of Drug-Resistant Tuberculosis in Spain (2001-2015).

Multidrug-resistant tuberculosis (MDR-TB) is a cause of increasing concern. This study investigated first-line anti-TB drug resistance in Mycobacterium tuberculosis strains submitted to the Tuberculosis Reference Center in Córdoba (Spain) between 2001 and 2015. A total of 1,207 cultures were tested against first-line drugs using the BACTEC MGIT 960 system. Resistance to first-line drugs was detected in 207 strains (17.2%), the greatest resistance being found in INH (5.3%) followed by streptomycin (3%), pyrazinamide (2.2%), rifampicin (1%), and ethambutol (0.2%). A total of 1.9% of strains were MDR-TB. Six strains displayed resistance to four drugs, and three strains to five drugs. In view of resistance observed, careful surveillance of drug resistance is recommended.