Outcomes of patients with multidrug-resistant pulmonary tuberculosis treated with ofloxacin/levofloxacin-containing regimens

Levofloxacin alleviates blood-brain barrier disruption following cerebral ischemia and reperfusion via directly inhibiting A-FABP

Reperfusion therapy is currently the most effective treatment for acute ischemic stroke, but often results in secondary brain injury. Adipocyte fatty acid-binding protein (A-FABP, FABP4, or aP2) was shown to critically mediate cerebral ischemia/reperfusion (I/R) injury by exacerbating blood-brain barrier (BBB) disruption. However, no A-FABP inhibitors have been approved for clinical use due to safety issues. Here, we identified the therapeutic effect of levofloxacin, a widely used antibiotic displaying A-FABP inhibitory activity in vitro, on cerebral I/R injury and determined its target specificity and action mechanism in vivo. Using molecular docking and site-directed mutagenesis, we showed that levofloxacin inhibited A-FABP activity through interacting with the amino acid residue Asp76, Gln95, Arg126 of A-FABP. Accordingly, levofloxacin significantly inhibited A-FABP-induced JNK phosphorylation and expressions of proinflammatory factors and matrix metalloproteinase 9 (MMP-9) in mouse primary macrophages. In wild-type mice with transient middle cerebral artery occlusion, levofloxacin substantially mitigated BBB disruption and neuroinflammation, leading to reduced cerebral infarction, alleviated neurological outcomes, and improved survival. Mechanistically, levofloxacin decreased MMP-9 expression and activity, and thus reduced degradation of extracellular matrix and endothelial tight junction proteins. Importantly, the BBB- and neuro-protective effects of levofloxacin were abolished in A-FABP or MMP-9 knockout mice, suggesting that the therapeutic effects of levofloxacin highly depended on specific targeting of the A-FABP-MMP-9 axis. Overall, our study demonstrates that levofloxacin alleviates A-FABP-induced BBB disruption and neural tissue injury following cerebral I/R, and unveils its therapeutic potential for the treatment of ischemic stroke.

Prolongation of Acid-Fast Bacilli Sputum Smear Positivity in Patients with Multidrug-Resistant Pulmonary Tuberculosis

The study sought to determine factors associated with prolonged smear positivity in multidrug-resistant tuberculosis (MDR-TB) patients following appropriate management. Newly diagnosed patients were enrolled between June 2017 and May 2018. Sputum samples were collected for Xpert® MTB/RIF and line probe assays (LiPAs). Microscopic tests were performed at baseline and 4, 8, and 12 weeks post-anti-TB therapy. Of the 200 patients, 114 (57%) were HIV-positive. After 12 weeks of treatment, there was a significant microscopy conversion rate among DS-TB patients compared to MDR-TB patients irrespective of their HIV status (p = 0.0013). All MDR-TB patients who had a baseline smear grade ranging from scanty to +1 converted negative, while 25% ranging from +2 to +3 remained positive until the end of 12 weeks (p = 0.014). Factors associated with smear positivity included age <35 years (p = 0.021), initial CD4+ T-cell count ≥200 cells/mm3 (p = 0.010), and baseline smear grade ≥2+ (p = 0.014). Cox regression showed that only the baseline smear grade ≥2+ was independently associated with prolonged smear positivity in MDR-TB patients (p = 0.011) after adjusting for HIV status, CD4+ T-cell count, and age. Baseline sputum smear grade ≥2+ is a key determinant for prolonged smear positivity beyond 12 weeks of effective anti-TB therapy in MDR-TB patients.

Unsuccessful treatment outcome and associated risk factors. A prospective study of DR-TB patients from a high burden country, Pakistan

INTRODUCTION

Tuberculosis (TB), a curable and preventable infectious disease, becomes difficult to treat if resistance against most effective and tolerable first line anti-TB drugs is developed. The objective of the present study was to evaluate the treatment outcomes and predictors of poor outcomes among drug-resistant tuberculosis (DR-TB) patients treated at a programmatic management unit of drug resistant tuberculosis (PMDT) unit, Punjab, Pakistan.

METHODS

This prospective observational study was conducted at a a PMDT unit in Multan, Punjab, Pakistan. A total of 271 eligible culture positive DR-TB patients enrolled for treatment at the study site between January 2016 and May 2017 were followed till their treatment outcomes were recorded. World Health Organization's (WHO) defined criteria was used for categorizing treatment outcomes. The outcomes of cured and treatment completed were collectively placed as successful outcomes, while death, lost to follow-up (LTFU) and treatment failure were grouped as unsuccessful outcomes. Multivariable binary logistic regression analysis was employed for getting predictors of unsuccessful treatment outcomes. A p-value <0.05 was considered statistically significant.

RESULTS

Of the 271 DR-TB patients analysed, nearly half (51.3%) were males. The patient's (Mean ± SD) age was 36.75 ± 15.69 years. A total of 69% patients achieved successful outcomes with 185 (68.2%) patients being cured and 2 (0.7%) completed therapy. Of the remaining 84 patients with unsuccessful outcomes, 48 (17.7%) died, 2 (0.7%) were declared treatment failure, 34 (12.5%) were loss to follow up. After adjusting for confounders, patients' age > 50 years (OR 2.149 (1.005-4.592) with p-value 0.048 and baseline lung cavitation (OR 7.798 (3.82-15.919) with p-value <0.001 were significantly associated with unsuccessful treatment outcomes.

CONCLUSIONS

The treatment success rate (69%) in the current study participants was below the target set by WHO (>75%). Paying special attention and timely intervention in patients with high risk of unsuccessful treatment outcomes may help in improving treatment outcomes at the study site.

Updated considerations in the diagnosis and management of tuberculosis infection and disease: integrating the latest evidence-based strategies

INTRODUCTION

Tuberculosis (TB) is a leading infectious cause of global morbidity and mortality, affecting nearly a quarter of the human population and accounting for over 10 million deaths each year. Over the past several decades, TB incidence and mortality have gradually declined, but 2021 marked a threatening reversal of this trend highlighting the importance of accurate diagnosis and effective treatment of all forms of TB.

AREAS COVERED

This review summarizes advances in TB diagnostics, addresses the treatment of people with TB infection and TB disease including recent evidence for treatment regimens for drug-susceptible and drug-resistant TB, and draws attention to special considerations in children and during pregnancy.

EXPERT OPINION

Improvements in diagnosis and management of TB have expanded the available options for TB control. Molecular testing has enhanced the detection of TB disease, but better diagnostics are still needed, particularly for certain populations such as children. Novel treatment regimens have shortened treatment and improved outcomes for people with TB. However, important questions remain regarding the optimal management of TB. Work must continue to ensure the potential of the latest developments is realized for all people affected by TB.

Tuberculosis treatment without rifampin in kidney/kidney-pancreas transplantation: A case series report

BACKGROUND

The best approach to tuberculosis (TB) treatment in transplanted patients is still unknown. Current guidelines are based on evidence either extrapolated from other populations or observational. Rifampin-containing regimens have strong pharmacokinetic interactions with immunosuppressive regimens, with high rates of organ dysfunction and ∼20% mortality. This report describes the results obtained using non-rifampin-containing regimens to treat confirmed TB in adult patients with kidney/kidney-pancreas transplantation.

METHODS

Retrospective data analysis from confirmed TB cases in adult kidney/kidney-pancreas transplant recipients (2006-2019), treated "de novo" with non-rifampin-containing regimens.

RESULTS

Fifty-seven patients had confirmed TB. Thirty patients were treated "de novo" with non-rifampin-containing regimens. These patients' mean age was 49.24 (±11.50) years. Induction immunosuppression was used in 22 patients. Maintenance immunosuppression was tacrolimus-mycophenolate-steroids in 13 (43%), sirolimus-mycophenolate-steroids in 6 (20%), and other immunosuppressive regimens in 11 (36%). Belatacept was used in four patients. TB localizations: pulmonary 43%; disseminated 23%; extrapulmonary 33%. Twenty-seven (90%) patients completed treatment with isoniazid, ethambutol, and levofloxacin (12 months, 23; 9 months, 3; 6 months, 1); 12 of these patients also received pyrazinamide for the first 2 months and were cured with functioning grafts. One patient (3%) lost the graft while on treatment. Two patients (7%) died while on TB treatment. Median (range) follow-up after completion of TB treatment was 32 (8-150) months. No TB relapses were observed.

CONCLUSIONS

Results with non-rifampin-containing TB treatments in this case series were better (in terms of mortality and graft dysfunction) than those previously described with rifampin-containing regimens in transplanted patients.

Design and synthesis of benzimidazole derivatives as antimycobacterial agents

A series of 2,5-disubstituted benzimidazole derivatives was synthesized with the aim to identify compounds with potent anti-TB activity. All the compounds were screened in vitro against cultured Mycobacterium tuberculosis H₃₇ Rv strain and found to be exhibiting MIC₉₉ values in the range of 0.195-100 µM. Out of 43 synthesized compounds, two compounds 11h and 13e showed better anti-TB activity than the reference drug isoniazid.

Radiological and functional evidence of the bronchial spread of tuberculosis: an observational analysis

BACKGROUND

Direct bronchial spread of tuberculosis was extensively described in pre-antibiotic human pathology literature but this description has been overlooked in the post-antibiotic era, in which most pathology data come from animal models that emphasise the granuloma. Modern techniques, such as [18F]2-fluoro-2-deoxy-D-glucose (FDG) PET-CT scans, might provide further insight. Our aim was to understand normal early tuberculosis resolution patterns on pulmonary PET-CT scans in treated patients with tuberculosis who were subsequently cured.

METHODS

In this observational analysis, we analysed data from PredictTB, an ongoing, prospective, randomised clinical trial that examined sequential baseline and week 4 FDG-PET-CT scans from participants successfully treated (sputum culture negative 18 months after enrolment) for drug-susceptible pulmonary tuberculosis in South Africa and China. Participants who were aged 18-75 years, GeneXpert MTB/RIF positive for tuberculosis and negative for rifampicin resistance, had not yet started tuberculosis treatment, had not been treated for active tuberculosis within the previous 3 years, and met basic safety laboratory criteria were included and participants with diabetes, HIV infection, or with extrapulmonary tuberculosis including pleural tuberculosis were excluded. Scans were assessed by two readers for the location of tuberculosis lesions (eg, cavities and consolidations), bronchial thickening patterns, and changes from baseline to week 4 of treatment.

FINDINGS

Among the first 124 participants (enrolled from June 22, 2017, to Sept 27, 2018) who were successfully treated, 161 primarily apical cavitary lesions were identified at baseline. Bronchial thickening and inflammation linking non-cavitary consolidative lesions to cavities were observed in 121 (98%) of 124 participants' baseline PET-CT scans. After 4 weeks of treatment, 21 (17%) of 124 participants had new or expanding lesions linked to cavities via bronchial inflammation that were not present at baseline, particularly participants with two or more cavities at baseline and participants from South Africa.

INTERPRETATION

In participants with pulmonary tuberculosis who were subsequently cured, the location of cavitary and non-cavitary lesions at baseline and new lesions at week 4 of treatment suggest a cavitary origin of disease and bronchial spread through the lungs. Bronchial spread from cavities might play a larger role in the spread of pulmonary tuberculosis than has been appreciated. Elucidating cavity lesion dynamics and Mycobacterium tuberculosis viability within cavities might better explain treatment outcomes and why some patients are cured and others relapse.

FUNDING

Bill & Melinda Gates Foundation, European and Developing Countries Clinical Trials Partnership, China Ministry of Science and Technology, National Natural Science Foundation of China, and National Institutes of Health.

TRANSLATIONS

For the Chinese, Afrikaans and Xhosa translations of the abstract see Supplementary Materials section.

Monocarbonyl curcuminoids as antituberculosis agents with their moderate in-vitro metabolic stability on human liver microsomes

Tuberculosis, an airborne infectious disease, results in a high morbidity and mortality rate. The continuous emergence of TB resistance strains including MDR (multidrug-resistant tuberculosis), XDR (extensive drug-resistant tuberculosis), and especially TDR (totally drug-resistant tuberculosis) is a major public health threat and has intensified the need to develop new antitubercular agents. A natural product, curcumin, possesses diverse biological activities but suffers due to a lack of water solubility and bioavailability. To overcome these limitations, a series of 17 water-soluble monocarbonyl curcuminoids was synthesized and evaluated for antimycobacterial activity. All compounds exhibited good to moderate anti-TB activity with MIC₉₉ in the range of 3.12-25.0 µM, out of which 7c and 7p were found the most potent compounds with MIC₉₉ in the range of 3.12-6.25 µM. Furthermore, these compounds were observed to be nonhaemolytic, nontoxic, and stable under both physiological as well as reducing conditions. In-vitro metabolic stability data of the representative compound 7p with the human liver microsome revealed that these compounds possess a moderate metabolism with a half-life of 1.2 h and an intrinsic clearance of 1.12 ml/h/mg.

Predicting TB treatment outcomes using baseline risk and treatment response markers: developing the PredictTB early treatment completion criteria

Standard treatment of drug-sensitive pulmonary tuberculosis requires six months of treatment. Several randomized clinical trials have attempted to shorten treatment to four months using various strategies but thus far all have failed. The PredictTB trial is an ongoing international randomized clinical trial testing a treatment shortening strategy whereby only drug-sensitive pulmonary TB patients who meet the study early treatment completion criteria are randomized to four vs. six months of treatment. The PredictTB early treatment completion criteria were developed based on a cohort of 92 pulmonary tuberculosis patients treated programmatically through the local tuberculosis treatment program in Cape Town, South Africa, with FDG-PET/CT scans also performed at baseline and week 4 of treatment. Patients were followed for one year after the end of therapy for programmatic treatment outcomes. This methodology paper describes how the PET/CT scans and GeneXpert cycle threshold data of this cohort were analyzed to develop the early treatment completion algorithm currently being used in the PredictTB trial.

Predictors of Time to Sputum Culture Conversion Among Drug-Resistant Tuberculosis Patients in Oromia Region Hospitals, Ethiopia

Purpose

Multi-drug-resistant tuberculosis occurs when the tuberculosis bacteria develop resistance to at least the two most effective first-line anti-tuberculosis drugs, isoniazid and rifampicin. Sputum culture conversion is one of the indicators to monitor patients’ prognosis throughout the treatment. Hence, this study aimed to assess time to culture conversion and its determinants among drug-resistant tuberculosis patients.

Patients and Methods

A total of 228 drug-resistant tuberculosis patients in selected hospitals in Oromia region, Ethiopia, were included in this study. Descriptive statistics like median time to sputum smear and culture conversion were computed. Bivariate and multivariate Cox proportional hazard models were used to identify the independent predictors of time to culture conversion. The adjusted hazard ratio (AHR) with 95% confidence interval (CI) was used to report the strength of association. Statistical significance was declared at p <0.05.

Results

The median age of the study participants was 28 years with inter-quartile range of (IQR) of 22–32 years, and 60% of the patients were male. The median time to culture conversion was 61 days (IQR: 34–92 days). The proportion of sputum culture conversion at 2nd, 4th, and 6th months of treatment initiation was 47%, 82.5%, and 89%, respectively. The final adjusted multivariate Cox proportional hazard model revealed that patients with massive effusion on chest radiographic finding had a 60%-decreased culture conversion time (AHR: 0.4, 95% CI: 0.1–0.9). Patients with abnormalities without cavitations (AHR: 0.5, 95% CI: 0.2–0.9) and those with uninterpreted findings (AHR: 0.3 95% CI: 0.1–0.5) had delayed culture conversion time.

Conclusion

Chest radiographic findings such as massive effusion, abnormalities without cavitations, and uninterpreted findings were found to be predictors of time to sputum culture conversion. Patients with such characteristics have prolonged culture conversion time. Hence, they may need special attention during the treatment.

Evaluation of risk factors associated with drug-resistant tuberculosis in Yemen: data from centres with high drug resistance

Background

The World Health Organization (WHO) has reported that Yemen has a high burden of drug resistance and a worrying shortage of implemented diagnostic methods and drug treatment regimens. Therefore, in this study, we evaluated the risk factors associated with multidrug-resistant tuberculosis (MDR-TB) and explored the poor TB management in Yemen.

Methods

Between January 2014 and December 2016, we enrolled 135 patients with MDR-TB from drug resistance programmes at four major TB centres in Yemen for this prospective study. After exclusion of 20 patients, treatment outcomes were reported for 115 patients who attended a series of follow-ups.

Results

A total of 115 patients with MDR-TB were analysed from the four main TB centres in Yemen. Most patients (35.2%) were from the Aden TB centre. A success rate of 77.4% was reported for TB treatment. Of the 115 patients, 69.6% were resistant to two drugs, 18.3% were resistant to three drugs, and 12.2% were resistant to four drugs. During the intensive phase of treatment, 19 patients (16.5%) reported one or more adverse events. A multivariate logistic regression analysis revealed that a baseline body weight of ≤40 kg [p = 0.016; adjusted odds ratio (AOR) = 25.09], comorbidity (p = 0.049; AOR = 4.73), baseline lung cavities (p = 0.004; AOR = 15.32), and positive culture at the end of the intensive phase (p = 0.009; AOR = 8.83) were associated with the unsuccessful treatment outcomes in drug-resistant TB patients.

Conclusions

The success rate achieved after treatment was below the levels established by the WHO End TB Strategy (90%) and the United Nations Sustainable Development Goals (80%). Identification of risk factors associated with MDR-TB in Yemen is essential because it allows health workers to identify high-risk patients, especially in the absence of a second-line treatment or a laboratory diagnostic method. The Yemen National Tuberculosis Control Program should formulate new strategies for early detection of MDR-TB and invest in new programmes for MDR-TB management.

Tuberculosis and HIV Coinfection–the Challenge in the Prevention, Detection and Treatment of Tuberculosis

Background:

Tuberculosis (TB) is still a major public health concern world-wide. The increasing global burden of TB is linked to HIV infection. HIV-TB coinfection has also conditioned clinical aspects of the TB. Since the HIV is beginning in the 1980s, the HIV infection poses a significant challenge in global TB control.

Objective:

In this review we focused on the challenges of epidemiological and clinical feature of tuberculosis presented by the HIV coinfection.

Method:

The article consists of a summary of the most important effects presented by the HIV coinfection on epidemiological and clinical feature of tuberculosis. The article analyzes and summary the causes for these challenges.

Results:

The major challenges to strategy of TB control and clinical feature of TB-HIV coinfection are presented in this paper.

Conclusion:

HIV/TB co-infection is synergic, interactive and reciprocal with significant impact. The infection of HIV and Mtb affect each other and the breakdown the immune function in TB/HIV coinfected individual. HIV infection has changed the strategy of TB control, however HIV increases global burden of TB, the reduction in the TB incidence rate is far from sufficient. Atypically clinical manifestations in TB/HIV co-infected patients and increased MDR-TB and XDR-TB contribute to the challenges in the diagnosis and treatment. Increased complexity of managing patients requires expertise in the clinical m knowledge. The focused efforts to control HIV-related TB are of great urgency. These findings will provide insight into the prevention, detection and treatment of tuberculosis and will guide advances towards tuberculosis control.

Mental health disorders, social stressors, and health-related quality of life in patients with multidrug-resistant tuberculosis: A systematic review and meta-analysis

BACKGROUND

Mental health disorders, social stress, and poor health-related quality of life are commonly reported among people with tuberculosis (TB). We conducted a systematic review and meta-analysis to quantify mental health disorders, social stressors, and health-related quality of life in patients with multidrug-resistant tuberculosis (MDR-TB).

METHODS

We searched PubMed, SCOPUS, ProQuest, Web of Science, and PsycINFO databases for studies that reported data on mental health disorders, social stressors, and health-related quality of life among MDR-TB patients. Hand-searching the reference lists of included studies was also performed. Studies were selected according to pre-defined selection criteria and data were extracted by two authors. Pooled prevalence and weighted mean difference estimates were performed using random-effects meta-analysis. Heterogeneity was explored using meta-regression, and subgroup analyses were performed.

RESULTS

We included a total of 40 studies that were conducted in 20 countries. Depression, anxiety, and psychosis were the most common mental health disorders reported in the studies. The overall pooled prevalence was 25% (95% confidence interval (CI): 14, 39) for depression, 24% (95% CI: 2, 57) for anxiety, and 10% (95% CI: 7, 14) for psychosis. There was substantial heterogeneity in the estimates. The stratified analysis showed that the prevalence of psychosis was 4% (95% CI: 0, 22) before MDR-TB treatment commencement, and 9% (95% CI: 5, 13) after MDR-TB treatment commencement. The most common social stressors reported were stigma, discrimination, isolation, and a lack of social support. Health-related quality of life was significantly lower among MDR-TB patients when compared to drug-susceptible TB patients (Q = 9.88, p = 0.01, I² = 80%).

CONCLUSIONS

This review found that mental health and social functioning are compromised in a significant proportion of MDR-TB patients, a finding confirmed by the poor health-related quality of life reported. Thus, there is a substantial need for integrating mental health services, social protection and social support into the clinical and programmatic management of MDR-TB.

Time to sputum culture conversion and its determinants among Multi-drug resistant Tuberculosis patients at public hospitals of the Amhara Regional State: A multicenter retrospective follow up study

Background

In Ethiopia, Multi-drug resistant Tuberculosis (MDR-TB) is one of the major public health problems that need great attention. Time to sputum culture conversion is often used as an early predictive value for the final treatment outcome. Although guidelines for MDR-TB are frequently designed, medication freely provided, and centers for treatment duly expanded, studies on time to sputum culture conversion have been very limited in Ethiopia. This study was aimed at determining the time to sputum culture conversion and the determinants among MDR-TB patients at public Hospitals of the Amhara Regional State.

Methods

A retrospective follow up study was conducted between September 2010 and December 2016. Three hundred ninety two MDR-TB patients were included in the study. Parametric frailty models were fitted and Cox Snell residual was used for goodness of fit, which the Akaike’s information criteria was used for model selection. Adjusted hazard ratio (AHR) with a 95% confidence interval (CI) was reported to show the strength of association.

Result

Out of the 392 participants, sputum culture changed for 340(86.7%) during the follow up period. The median culture conversion time in this study was 65 (60–70 days). Alcohol drinking (AHR = 3.79, 95%CI = 1.65–8.68), sputum smear grading +2 (AHR = 0.39, 95%CI 0.19–0.79), smear grading +3 (AHR = 0.30, CI = 0.14–064), cavitations (AHR = 0.36, 95%CI = 0.19–0.68), and consolidation (AHR = 0.29, CI = 0.13–0.69) were the determinants of time to sputum culture conversion.

Conclusion

In this study, time to sputum culture was rapid as compared to 4 months WHO recommendation. Alcohol drinking, sputum smear grading, cavitations and consolidations were found to be the determinants of time to sputum culture conversion. Therefore, providing a special attention to patients who had baseline radiological finding is recommended, high bacillary load and patients with a history of alcohol intake at baseline should be given priority.

Validity of Time to Sputum Culture Conversion to Predict Cure in Patients with Multidrug-Resistant Tuberculosis: A Retrospective Single-Center Study

To evaluate the predictive value of time to sputum culture conversion (SCC) in predicting cure and factors associated with time to SCC and cure in multidrug-resistant tuberculosis (MDR-TB) patients, a retrospective study was conducted at programmatic management unit of drug resistant tuberculosis (TB), Peshawar. A total of 428 pulmonary MDR-TB patients enrolled at the study site from January 1, 2012 to August 31, 2014 were followed until treatment outcome was recorded. Survival analysis using Cox proportional hazards model and multivariate binary logistic regression were, respectively, used to identify factors associated with time to SCC and cure. A P value < 0.05 was considered statistically significant. Overall, 90.9% patients achieved SCC, and 76.9% were cured. Previous use of second-line drugs (SLDs) (hazard ratio [HR] = 0.637; 95% confidence interval [CI] = 0.429-0.947), ofloxacin resistance (HR = 0.656; 95% CI = 0.522-0.825) and lung cavitation (HR = 0.744; 95% CI = 0.595-0.931) were significantly associated with time to SCC. In predicting cure, sensitivities of SCC at 2, 4, and 6 months were 64.1% (95% CI = 58.69-69.32), 93.0% (95% CI = 89.69-95.52), and 97.6% (95% CI = 95.27-98.94), respectively, whereas specificities were 67.7% (95% CI = 57.53-76.73), 51.5% (95% CI = 41.25-61.68), and 44.4% (95% CI = 34.45-54.78), respectively. Furthermore, patients' age of 41-60 (odds ratio [OR] = 0.202; 95% CI = 0.067-0.605) and > 60 years (OR = 0.051; 95% CI = 0.011-0.224), body weight > 40 kg (OR = 2.950; 95% CI = 1.462-5.952), previous SLD use (OR = 0.277; 95% CI = 0.097-0.789), lung cavitation (OR = 0.196; 95% CI = 0.103-0.371) and ofloxacin resistance (OR = 0.386; 95% CI = 0.198-0.749) were significantly associated with cure. Association of SCC with cure was substantially stronger at 6 months (OR = 32.10; 95% CI = 14.34-71.85) than at 4 months (OR = 14.13; 95% CI = 7.92-25.21). However in predicting treatment outcomes, the combined sensitivity and specificity of SCC at 4 months was comparable to SCC at 6 months. Patients with risk factors for delayed SCC were also at high risk of unsuccessful outcomes.

Radiological signs associated with pulmonary multi-drug resistant tuberculosis: an analysis of published evidences

Background

Despite that confirmative diagnosis of pulmonary drug-sensitive tuberculosis (DS-TB) and multidrug resistant tuberculosis (MDR-TB) is determined by microbiological testing, early suspicions of MDR-TB by chest imaging are highly desirable in order to guide diagnostic process. We aim to perform an analysis of currently available literatures on radiological signs associated with pulmonary MDR-TB.

Methods

A literature search was performed using PubMed on January 29, 2018. The search words combination was "((extensive* drug resistant tuberculosis) OR (multidrug-resistant tuberculosis)) AND (CT or radiograph or imaging or X-ray or computed tomography)". We analyzed English language articles reported sufficient information of radiological signs of DS-TB vs. MDR-TB.

Results

Seventeen articles were found to be sufficiently relevant and included for analysis. The reported pulmonary MDR-TB cases were grouped into four categories: (I) previously treated (or 'secondary', or 'acquired') MDR-TB in HIV negative (-) adults; (II) new (or 'primary') MDR-TB in HIV(-) adults; (III) MDR-TB in HIV positive (+) adults; and (IV) MDR-TB in child patients. The common radiological findings of pulmonary MDR-TB included centrilobular small nodules, branching linear and nodular opacities (tree-in-bud sign), patchy or lobular areas of consolidation, cavitation, and bronchiectasis. While overall MDR-TB cases tended to have more extensive disease, more likely to be bilateral, to have pleural involvement, to have bronchiectasis, and to have lung volume loss; these signs alone were not sufficient for differential diagnosis of MDR-TB. Current literatures suggest that the radiological sign which may offer good specificity for pulmonary MDR-TB diagnosis, though maybe at the cost of low sensitivity, would be thick-walled multiple cavities, particularly if the cavity number is ≥3. For adult HIV(-) patients, new MDR-TB appear to show similar prevalence of cavity lesion, which was estimated to be around 70%, compared with previously treated MDR-TB.

Conclusions

Thick-walled multiple cavity lesions present the most promising radiological sign for MDR-TB diagnosis. For future studies cavity lesion characteristics should be quantified in details.

Using biomarkers to predict TB treatment duration (Predict TB): a prospective, randomized, noninferiority, treatment shortening clinical trial

Background: By the early 1980s, tuberculosis treatment was shortened from 24 to 6 months, maintaining relapse rates of 1-2%. Subsequent trials attempting shorter durations have failed, with 4-month arms consistently having relapse rates of 15-20%. One trial shortened treatment only among those without baseline cavity on chest x-ray and whose month 2 sputum culture converted to negative. The 4-month arm relapse rate decreased to 7% but was still significantly worse than the 6-month arm (1.6%, P<0.01).  We hypothesize that PET/CT characteristics at baseline, PET/CT changes at one month, and markers of residual bacterial load will identify patients with tuberculosis who can be cured with 4 months (16 weeks) of standard treatment.

Methods: This is a prospective, multicenter, randomized, phase 2b, noninferiority clinical trial of pulmonary tuberculosis participants. Those eligible start standard of care treatment. PET/CT scans are done at weeks 0, 4, and 16 or 24. Participants who do not meet early treatment completion criteria (baseline radiologic severity, radiologic response at one month, and GeneXpert-detectable bacilli at four months) are placed in Arm A (24 weeks of standard therapy). Those who meet the early treatment completion criteria are randomized at week 16 to continue treatment to week 24 (Arm B) or complete treatment at week 16 (Arm C). The primary endpoint compares the treatment success rate at 18 months between Arms B and C.

Discussion: Multiple biomarkers have been assessed to predict TB treatment outcomes. This study uses PET/CT scans and GeneXpert (Xpert) cycle threshold to risk stratify participants. PET/CT scans are not applicable to global public health but could be used in clinical trials to stratify participants and possibly become a surrogate endpoint. If the Predict TB trial is successful, other immunological biomarkers or transcriptional signatures that correlate with treatment outcome may be identified. Trial Registration: NCT02821832

Predictors of unsuccessful interim treatment outcomes of multidrug resistant tuberculosis patients

Background

Interim treatment outcomes at 6-months for multidrug-resistant tuberculosis (MDR-TB) treatment are among the most basic performance monitoring and key evaluation indicators in the Stop and End TB strategy of the World Health Organization (WHO). Therefore, this study was conducted to evaluate the interim treatment outcomes of MDR-TB patients in Pakistan.

Methods

This study was conducted at the Programmatic Management Unit for Drug-resistance TB (PMDT) site of the National Tuberculosis Program (NTP), Pakistan. It is located in the Chest Disease Unit (CDU) of the Bahawal Victoria Hospital (BVH), Bahawalpur, Punjab, Pakistan. Data was collected between April 1, 2014 and December 31, 2015. The medical records, Electronic Nominal Recording Reporting System (ENRS) data and MRD-TB notification forms of the MDR-TB patients registered at the PMDT site were reviewed to obtain data. For reporting and calculation of interim treatment outcomes, standardized WHO methodology was adopted. Simple logistic regression analysis was used to examine the possible association between the dependent variable (i.e. unsuccessful interim treatment outcome) and selected socio-demographic and clinical variables.

Results

A total of 100 drug-resistant TB (DR-TB) patients (all types) were registered during the study period. Out of these, 80 were MDR-TB patients for whom interim results were available. Out of the 80 MDR-TB cases, 48 (60%) were classified under the successful interim treatment outcome category. The remaining 40% had unsuccessful 6-month treatment outcomes and 12 (15%) patients died, while nine (11.3%) were lost to follow-up by six months. The final predictors of unsuccessful interim treatment outcomes were; being resistant to ofloxacin (AOR 3.23, 95% CI 0.96–10.89; p-value = 0.04), having above normal baseline serum creatinine levels (AOR 6.49, 95% CI 1.39–30.27; p-value = 0.02), and being culture positive at the second month of treatment (AOR 6.94, 95% CI 2–24.12; p-value = 0.01).

Conclusions

Despite free treatment and programmatic efforts to ensure patient adherence, the high rate of unsuccessful interim treatment outcomes is concerning. The identified risk factors for unsuccessful interim treatment outcomes in the current study provides clinicians an opportunity to identify high-risk patients and ensure enhanced clinical management and greater treatment success rates.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2746-5) contains supplementary material, which is available to authorized users.

Pharmacokinetics of Levofloxacin in Multidrug- and Extensively Drug-Resistant Tuberculosis Patients

Pharmacodynamics are especially important in the treatment of multidrug- and extensively drug-resistant tuberculosis (M/XDR-TB). The free area under the concentration time curve in relation to MIC (fAUC/MIC) is the most relevant pharmacokinetic (PK)-pharmacodynamic (PD) parameter for predicting the efficacy of levofloxacin (LFX). The objective of our study was to assess LFX PK variability in M/XDR-TB patients and its potential consequence for fAUC/MIC ratios. Patients with pulmonary M/XDR-TB received LFX as part of the treatment regimen at a dose of 15 mg/kg administered once daily. Blood samples obtained at steady state before and 1, 2, 3, 4, 7, and 12 h after drug administration were measured by validated liquid chromatography-tandem mass spectrometry. The MIC values of LFX were determined by the agar dilution method on Middlebrook 7H10 and the MGIT960 system. Twenty patients with a mean age of 31 years (interquartile range [IQR] = 27 to 35 years) were enrolled in this study. The median AUC_0-24 was 98.8 mg/h/liter (IQR = 84.8 to 159.6 mg/h/liter). The MIC median value for LFX was 0.5 mg/liter with a range of 0.25 to 2.0 mg/liter, and the median fAUC_0-24/MIC ratio was 109.5 (IQR = 48.5 to 399.4). In 4 of the 20 patients, the value was below the target value of ≥100. When MICs of 0.25, 0.5, 1.0, and 2.0 mg/liter were applicable, 19, 18, 3, and no patients, respectively, had an fAUC/MIC ratio that exceeded 100. We observed a large variability in AUC. An fAUC_0-24/MIC of ≥100 was only observed when the MIC values for LFX were 0.25 to 0.5 mg/liter. Dosages exceeding 15 mg/kg should be considered for target attainment if exposures are assumed to be safe. (This study has been registered at ClinicalTrials.gov under registration no. NCT02169141.).

Side effects associated with the treatment of multidrug-resistant tuberculosis at a tuberculosis referral hospital in South Korea: A retrospective study

Patients with drug-susceptible tuberculosis (TB) show good tolerance of the medications used and have few side effects. However, medications used to treat multidrug-resistant tuberculosis (MDR-TB) have many known side effects. Here, we studied the occurrence of side effects due to treatment of patients with MDR-TB.We conducted a retrospective and consecutive review of the medical records of 256 patients who received treatment for MDR-TB between January 2006 and December 2011.One or more side effects were observed in 95 (37.1%) of the 256 patients. These side effects led to the suspension of the use of 1 or more drugs from the regimen of individualized treatment prescribed for 44 of the patients (17.2%). The side effects observed most frequently included gastrointestinal disturbance (18.4%), psychiatric disorder (5.5%), arthralgia (4.7%), hepatitis (3.9%), peripheral neuropathy (3.1%), hypothyroidism (2.3%), epileptic seizures (2%), dermatological effects (2%), ototoxicity (1.6%), and nephrotoxicity (1.2%). The treatment was successful in 220 (85.9%) patients with MDR-TB.Our study may help in formulating strategies for the timely and aggressive management of drug side effects. This may reduce the suspension of therapy and increase the rate of clinical success.

Study of factors influencing response and outcome of Cat-IV regimen in MDRTB patients

BACKGROUND

CAT IV regimen or the standardized drug regimen (SDR) under the Revised National Control Program (RNTCP) uses six second-line anti-tubercular drugs in the initial intensive phase (IP). These drugs have many side effects and toxicity; they are less efficacious and have poor acceptability. The present study was conducted to evaluate the efficacy and outcome of Cat-IV regimen and the factors which influence the treatment outcome in MDR TB patients.

METHODS

It was a prospective observational study, which was done in the CAT II treatment failure, LPA proven MDR TB patients, above the age of 18 years, who were referred to DOTS Plus center for treatment. The study was approved by the hospital ethics committee and patient consent was obtained before inclusion.

RESULTS

We observed culture conversion in 63.04% and ADR in 96.5%, default in 15.65%, and death in11.3% cases. The factors which influenced outcome included low body weight, long duration of illness cavitatory disease and indulgence in both tobacco & alcohol. The radiological favorable response strongly and significantly correlated with the bacteriological and clinical response during the IP.

CONCLUSION

We suggest that the efficacy can be further augmented by reducing default and controlling deaths which accounts for substantial numbers and occur mostly during IP.

Characteristics and treatment outcomes of patients with multi-drug resistant tuberculosis at a tertiary care hospital in Peshawar, Pakistan

OBJECTIVES

To determine characteristics and treatment outcomes of multidrugs resistant tuberculosis (MDR-TB) patients and risk factors for poor outcomes in MDR-TB patients in a tertiary care hospital in Peshawar, Pakistan. 

METHODS

This retrospective study was conducted at the Programmatic Management of Drug Resistant TB Unit, Lady Reading Hospital Peshawar, Pakistan and included all MDR-TB patients registered between January 2012 and December 2012. A special proforma was used for data collection. Analysis was performed using SPSS version 16, after exporting data from the proforma. Differences in proportions were assessed using Pearson's Chi square test whereas for predictors of poor outcomes, multivariate logistic regression analysis with Wald Statistical criteria using backward elimination method was performed. 

RESULTS

The treatment success rate was 74.3%. In univariate analysis, poor outcomes were associated in patients with age ≥44 years (odds ratio [OR]=0.250; 95% confidence interval [CI]: 0.114-0.519, p=0.001), rural residence (OR=0.417; 95% CI: 0.18-0.937, p=0.03), lung cavitation (OR=0.22; 95% CI, 0.007-0.067, p=0.001), resistance to second line drugs (SLD) (OR=3.441; 95% CI: 1.579-7.497, p=0.001), and resistance to ofloxacin (OR=2.944; 95% CI: 1.361-6.365, p=0.005); whereas multivariate logistic regression analysis, poor outcomes were associated in patients with age ≥44 years (OR=0.249, 95% CI: 0.075-0.828, p=0.023), rural residence (OR=0.143, 95% CI: 0.052-0.774, p=0.032), and cavitatory lungs (OR=0.022, 95% CI: 0.007-0.072, p=0.000). 

CONCLUSION

The MDR-TB patient needs special attention for better treatment outcomes. The presence of older age, rural area residence, resistance to ofloxacin, SLD resistance, and cavitary disease are independent prognostic factors for poor outcome in patients with MDR-TB.

Recognizing drug targets using evolutionary information: implications for repurposing FDA-approved drugs against Mycobacterium tuberculosis H37Rv

Drug repurposing to explore target space has been gaining pace over the past decade with the upsurge in the use of systematic approaches for computational drug discovery. Such a cost and time-saving approach gains immense importance for pathogens of special interest, such as Mycobacterium tuberculosis H37Rv. We report a comprehensive approach to repurpose drugs, based on the exploration of evolutionary relationships inferred from the comparative sequence and structural analyses between targets of FDA-approved drugs and the proteins of M. tuberculosis. This approach has facilitated the identification of several polypharmacological drugs that could potentially target unexploited M. tuberculosis proteins. A total of 130 FDA-approved drugs, originally intended against other diseases, could be repurposed against 78 potential targets in M. tuberculosis. Additionally, we have also made an attempt to augment the chemical space by recognizing compounds structurally similar to FDA-approved drugs. For three of the attractive cases we have investigated the probable binding modes of the drugs in their corresponding M. tuberculosis targets by means of structural modelling. Such prospective targets and small molecules could be prioritized for experimental endeavours, and could significantly influence drug-discovery and drug-development programmes for tuberculosis.

Sequence Analysis of Fluoroquinolone Resistance-Associated Genes gyrA and gyrB in Clinical Mycobacterium tuberculosis Isolates from Patients Suspected of Having Multidrug-Resistant Tuberculosis in New Delhi, India

Fluoroquinolones (FQs) are broad-spectrum antibiotics recommended for the treatment of multidrug-resistant tuberculosis (MDR-TB) patients. FQ resistance, caused by mutations in the gyrA and gyrB genes of Mycobacterium tuberculosis, is increasingly reported worldwide; however, information on mutations occurring in strains from the Indian subcontinent is scarce. Hence, in this study, we aimed to characterize mutations in the gyrA and gyrB genes of acid-fast bacillus (AFB) smear-positive sediments or of M. tuberculosis isolates from AFB smear-negative samples from patients in India suspected of having MDR-TB. A total of 152 samples from patients suspected of having MDR-TB were included in the study. One hundred forty-six strains detected in these samples were characterized by sequencing of the gyrA and gyrB genes. The extracted DNA was subjected to successive amplifications using a nested PCR protocol, followed by sequencing. A total of 27 mutations were observed in the gyrA genes of 25 strains, while no mutations were observed in the gyrB genes. The most common mutations occurred at amino acid position 94 (13/27 [48.1%]); of these, the D94G mutation was the most prevalent. The gyrA mutations were significantly associated with patients with rifampin (RIF)-resistant TB. Heterozygosity was seen in 4/27 (14.8%) mutations, suggesting the occurrence of mixed populations with different antimicrobial susceptibilities. A high rate of FQ-resistant mutations (17.1%) was obtained among the isolates of TB patients suspected of having MDR-TB. These observations emphasize the need for accurate and rapid molecular tests for the detection of FQ-resistant mutations at the time of MDR-TB diagnosis.

Fluoroquinolone-resistant tuberculosis: implications in settings with weak healthcare systems

Fluoroquinolones (FQ) play an essential role in the treatment and control of multidrug-resistant tuberculosis (MDR-TB). They are also being evaluated as part of newer regimens under development for drug-sensitive TB. As newer FQ-based regimens are explored, knowledge of FQ resistance data from high TB burden countries becomes essential. We examine available FQ resistance data from high TB burden countries and demonstrate the need for comprehensive surveys to evaluate FQ resistance in these countries. The factors driving FQ resistance in such conditions and the cost of such resistance to weak healthcare systems are discussed. The need for a comprehensive policy for addressing the issue of FQ resistance is highlighted.

Risk factors for acquisition of drug resistance during multidrug-resistant tuberculosis treatment, Arkhangelsk Oblast, Russia, 2005-2010

Resistance should be determined quickly, and treatment should contain at least 3 effective drugs.

Acquired resistance to antituberculosis drugs decreases effective treatment options and the likelihood of treatment success. We identified risk factors for acquisition of drug resistance during treatment for multidrug-resistant tuberculosis (MDR TB) and evaluated the effect on treatment outcomes. Data were collected prospectively from adults from Arkhangelsk Oblast, Russia, who had pulmonary MDR TB during 2005–2008. Acquisition of resistance to capreomycin and of extensively drug-resistant TB were more likely among patients who received <3 effective drugs than among patients who received >3 effective drugs (9.4% vs. 0% and 8.6% vs. 0.8%, respectively). Poor outcomes were more likely among patients with acquired capreomycin resistance (100% vs. 25.9%), acquired ofloxacin resistance (83.6% vs. 22.7%), or acquired extensive drug resistance (100% vs. 24.4%). To prevent acquired drug resistance and poor outcomes, baseline susceptibility to first- and second-line drugs should be determined quickly, and treatment should be adjusted to contain >3 effective drugs.

Shortening Tuberculosis Treatment With Fluoroquinolones: Lost in Translation?

The disappointing recent failure of fluoroquinolone-containing regimens to shorten the duration of tuberculosis treatment in costly phase 3 trials has raised serious questions about the reliability of preclinical tuberculosis models, especially mice, and the current paradigm of regimen development. Therefore we re-examined data from murine models and early-stage clinical trials on which the pivotal trials were based, concluding that phase 3 trial results were in line with preceding studies. Finally, we offer suggestions for a more efficient and integrated preclinical and clinical regimen development program where quantitative pharmacokinetic and pharmacodynamic models more predictive of curative treatment durations are set forth.

Treatment outcomes in multidrug resistant tuberculosis-human immunodeficiency virus Co-infected patients on anti-retroviral therapy at Sizwe Tropical Disease Hospital Johannesburg, South Africa

BACKGROUND

Multidrug resistant-tuberculosis (MDR-TB) is a threat to global tuberculosis control which is worsened by human immune-deficiency virus (HIV) co-infection. There is however paucity of data on the effects of antiretroviral treatment (ART) before or after starting MDR-TB treatment. This study determined predictors of mortality and treatment failure among HIV co-infected MDR-TB patients on ART.

METHODS

A retrospective medical record review of 1200 HIV co-infected MDR-TB patients admitted at Sizwe Tropical Disease Hospital, Johannesburg from 2007 to 2010 was performed. Chi-square test was used to determine treatment outcomes in HIV co-infected MDR-TB patients on ART. Multivariable logistic regression and Poisson models were used to determine predictors of mortality and treatment failure respectively.

RESULTS

Mortality was higher (21.8% vs. 15.4%) among patients who started ART before initiating MDR-TB treatment compared with patients initiated on ART after commencing MDR-TB treatment (p = 0.013). Factors significantly associated with mortality included: the use of ART before starting MDR-TB treatment (OR 1.65, 95% CI 1.02-2.73), severely-underweight (OR 3.71, 95% CI 1.89-7.29) and underweight (OR 2.35, 95% CI 1.30-4.26), cavities on chest x-rays at baseline (OR 1.76, 95% CI 1.08-2.94), presence of other opportunistic infections (OR 1.80, 95% CI 1.10-2.94) and presence of other co-morbidities (OR 2.26, 95% CI 1.20-4.21). Factors predicting failure were severe anaemia (IRR (OR 4.72, 95% CI 1.47-15), other co-morbidities (OR 2.39, 95% CI 1.05-5.43) and modified individualised regimen at baseline (OR 2.15, 95% CI 0.98-4.71).

CONCLUSIONS

High mortality among patients already on ART before initiating MDR-TB treatment is a worrisome development. Management of adverse-events, opportunistic infections and co-morbidities in these patients is important if the protective benefits of being on ART are to be maximized. There is the need to intensify intervention programmes targeted at early identification of MDR-TB, treatment initiation, drug monitoring and increasing adherence among HIV co-infected MDR-TB patients.

Good quality locally procured drugs can be as effective as internationally quality assured drugs in treating multi-drug resistant tuberculosis

Background

Owing toGiven the high costs of drugs to treat multi-drug resistant tuberculosis (MDR-TB), the Green Light Committee (GLC) initiative enables TB programs to procure quality-assured drugs at reduced prices. Despite price reductions, internationally quality assured (IQA) drugs can be more expensive than locally procured drugs. There is little evidence to inform decision-makers about whether IQA drugs are more effective than local drugs. This is the first study to compare outcomes between MDR-TB patients treated using IQA, and locally procured drugs in the same hospitals during the same time period.

Methods/Findings

A retrospective cohort study was conducted in three hospitals across Pakistan. Data on baseline characteristics and treatment outcomes during the first six months of treatment were extracted from hospital records of adult culture-positive pulmonary MDR-TB patients starting treatment between January 2011 and June 2012. Two cohorts were defined: patients receiving IQA drugs, and patients receiving locally procured non-IQA drugs. Data were analysed using Kaplan-Meier curves and Cox proportional hazards regression. The primary outcome compared between cohorts was time to culture conversion. Of 231 patients, 90 were in the IQA and 141 in the non-IQA cohorts. Baseline characteristics were similar except for higher frequency of quinolone resistance in the IQA cohort. Overall, 193 patients (84%) culture converted. Culture conversion was not faster in the IQA cohort; the median time was 81 and 68 days in the IQA and non-IQA cohorts, respectively. Unadjusted and adjusted hazard ratios for culture conversion in IQA verses non-IQA cohorts were 0.82 (95%-CI, 0.62-1.10) and 0.95 (95%-CI, 0.66-1.36) respectively.

Conclusions

Use of good quality, locally procured drugs can be effective in treating MDR-TB, may involve lower costs than using IQA drugs and could strengthen developing country drug quality assurance systems. This may be a suitable alternative in lieu of or whilst awaiting arrival of internationally procured medicines.

Predictors of cure among HIV co-infected multidrug-resistant TB patients at Sizwe Tropical Disease Hospital Johannesburg, South Africa

BACKGROUND

The global incidence of multidrug-resistant tuberculosis (MDR-TB) is rising, especially among HIV infected patients, despite intervention programs. Limited data are available on outcomes of MDR-TB treatment, specifically in a cohort of HIV co-infected patients in sub-Saharan Africa. The objective of this study was to determine the predictors of cure among MDR-TB HIV co-infected patients.

METHODS

A retrospective review of 1200 medical records of HIV co-infected MDR-TB patients was performed at Sizwe Tropical Disease Hospital, Johannesburg covering the period 2007 to 2010. Logistic regression analysis was done to identify predictors of cure.

RESULTS

Of 1137 patients included in the analysis, 29.8% (339/1137) were cured, 16.5% (188/1137) completed treatment, 22.3% (254/1137) defaulted treatment, 2.9% (33/1137) failed treatment and 22.7% (258/1137) died while on treatment. The remaining 5.7% (65/1137) were transferred-out or still-on-treatment. There was a significant interaction between sex and timing of antiretroviral treatment (ART) initiation (p=0.008). Factors predicting cure were male patients on ART prior to commencing MDR-TB treatment (OR 1.87, [1.11-3.13]), CD4(+) cell counts between 201-349 (OR 2.06, [1.10-3.84]) and ≥ 350 cells/mm³ (OR 1.98, [0.98-3.97]). Negative predictors of cure included the presence of cavitary lesions on chest x-rays (OR 0.55, [0.38-0.78]) and modified individualised regimen at baseline (OR 0.62, [0.42-0.92]).

CONCLUSIONS

Cure was higher in males on ART prior to initiating MDR-TB treatment compared with males on ART after initiating MDR-TB treatment. The inverse was the case among females. Therefore, future research should explore the biological and behavioural mechanisms that may possibly be responsible for this observed trend. This will help improve MDR-TB treatment outcomes in HIV co-infected patients on ART.

Treatment outcomes of patients with multidrug-resistant and extensively drug-resistant tuberculosis according to drug susceptibility testing to first- and second-line drugs: an individual patient data meta-analysis

BACKGROUND

Individualized treatment for multidrug-resistant (MDR) tuberculosis and extensively drug-resistant (XDR) tuberculosis depends upon reliable and valid drug susceptibility testing (DST) for pyrazinamide, ethambutol, and second-line tuberculosis drugs. However, the reliability of these tests is uncertain, due to unresolved methodological issues. We estimated the association of DST results for pyrazinamide, ethambutol, and second-line drugs with treatment outcomes in patients with MDR tuberculosis and XDR tuberculosis.

METHODS

We conducted an analysis of individual patient data assembled from 31 previously published cohort studies of patients with MDR and XDR tuberculosis. We used data on patients' clinical characteristics including DST results, treatment received, outcomes, and laboratory methods in each center.

RESULTS

DST methods and treatment regimens used in different centers varied considerably. Among 8955 analyzed patients, in vitro susceptibility to individual drugs was consistently and significantly associated with higher odds of treatment success (compared with resistance to the drug), if that drug was used in the treatment regimen. Various adjusted and sensitivity analyses suggest that this was not explained by confounding. The adjusted odds of treatment success for ethambutol, pyrazinamide, and the group 4 drugs ranged from 1.7 to 2.3, whereas for second-line injectables and fluoroquinolones, odds ranged from 2.4 to 4.6.

CONCLUSIONS

DST for ethambutol, pyrazinamide, and second-line tuberculosis drugs appears to provide clinically useful information to guide selection of treatment regimens for MDR and XDR tuberculosis.

Fluoroquinolone resistance in non-multidrug-resistant tuberculosis-a surveillance study in New South Wales, Australia, and a review of global resistance rates

BACKGROUND

Fluoroquinolones (FQs) are used for drug-susceptible tuberculosis (TB) in patients unable to tolerate first-line agents. Current trials are also investigating these drugs in empiric first-line TB therapy, to improve outcomes and allow for shortened treatment regimens. Widespread FQ use in the community has resulted in FQ resistance in many microorganisms, including Mycobacterium tuberculosis. Despite this, FQ drug susceptibility testing (DST) is rarely performed in non-multidrug-resistant TB (non-MDR-TB).

METHODS

We conducted a 1-year surveillance study of FQ resistance on all MTB isolates from New South Wales (NSW), Australia. In addition, we performed a literature review of previous studies assessing FQ resistance in non-MDR-TB to summarize the global extent of this resistance pattern.

RESULTS

Two (0.6%) out of 357 MTB isolates from NSW were found to be FQ-resistant. One isolate was an MDR strain (11% of all MDR-TB). The other was isoniazid-monoresistant (0.3% of all non-MDR-TB). Eleven studies from 10 countries had performed FQ resistance surveillance on non-MDR-TB. In the majority of these studies, FQ resistance was found to be low (mean 1%; 95% confidence interval 0.2-2%).

CONCLUSIONS

FQ resistance in non-MDR-TB is uncommon in NSW, Australia. The existing global evidence suggests that FQ resistance remains largely confined to MDR-TB strains. In the majority of TB endemic regions, however, FQ resistance in non-MDR-TB has not been assessed. Knowledge of the prevalence of FQ resistance in MTB is essential to guide the rational use of these drugs, including their feasibility as first-line agents.

Prescription patterns and treatment outcomes of MDR-TB patients treated within and outside the National Tuberculosis Programme in Pham Ngoc Thach hospital, Viet Nam

OBJECTIVE

To describe and analyse the prescription patterns and treatment outcomes of MDR-TB patients managed within Green Light Committee (GLC) and outside (non-GLC) the National TB programme in Viet Nam.

METHODS

Retrospective cohort study with two elements: (i) in-depth interviews and focus group discussions with clinical doctors, hospital pharmacists, and the non-GLC patients with MDR-TB; (ii) review of treatment cards and patients' charts of all GLC and non-GLC patients with MDR-TB put on treatment during 2010.

RESULTS

Of 282 patients with MDR-TB, comprising 79 (28%) GLC patients MDR-TB and 203 (72%) non-GLC patients with MDR-TB, were enrolled in the study. Treatment delay was significantly higher in the GLC group (12.8 days) than the non-GLC group (2.3 days), (P = 0.004). The success rate was significantly better in GLC patients (84.8%) than in non-GLC patients (53.7%) (P < 0.001). The default rate was significantly higher in non-GLC patients than in GLC patients (25.6% vs. 6.3%), (P < 0.001). The risk of unsuccessful outcome was higher in non-GLC patients (Hazard ratio = 4.6, 95% CI: 1.8-11.8).

CONCLUSIONS

The treatment outcomes of patients with MDR-TB in the GLC group were significantly better than in the non-GLC group. Reasons for the high default rate in non-GLC patients with MDR-TB must be further investigated.

Pseudo-outbreak of pre-extensively drug-resistant (Pre-XDR) tuberculosis in Kinshasa: collateral damage caused by false detection of fluoroquinolone resistance by GenoType MTBDRsl

Fluoroquinolones are the core drugs for the management of multidrug-resistant tuberculosis (MDR-TB). Molecular drug susceptibility testing methods provide considerable advantages for scaling up programmatic management and surveillance of drug-resistant TB. We describe here the misidentification of fluoroquinolone resistance by the GenoType MTBDRsl (MTBDRsl) (Hain Lifescience GmbH, Nehren, Germany) line probe assay (LPA) encountered during a feasibility and validation study for the introduction of this rapid drug susceptibility test in Kinshasa, Democratic Republic of Congo. The double gyrA mutation 80Ala and 90Gly represented 57% of all fluoroquinolone mutations identified from MDR-TB patient sputum samples, as confirmed by DNA sequencing. This double mutation was previously found to be associated with susceptibility to fluoroquinolones, yet it leads to absent hybridization of a wild-type band in the MTBDRsl and is thus falsely scored as resistance. Our findings suggest that MTBDRsl results must be interpreted with caution when the interpretation is based solely on the absence of a wild-type band without confirmation by visualization of a mutant band. Performance of the MTBDRsl LPA might be improved by replacing the gyrA wild-type probes by additional probes specific for well-documented gyrA mutations that confer clinically relevant resistance.

Predictors of two months culture conversion in multidrug-resistant tuberculosis: findings from a retrospective cohort study

BACKGROUND

Various studies have reported culture conversion at two months as a predictor of successful treatment outcome in multidrug-resistant tuberculosis (MDR-TB).

OBJECTIVES

The present study was conducted with the aim to evaluate the rate and predictors of culture conversion at two months in MDR-TB patients.

METHODS

All confirmed pulmonary MDR-TB patients enrolled for treatment at Lady Reading Hospital Peshawar, Pakistan from 1 January to 31 December 2012 and met the inclusion criteria were reviewed retrospectively. Rate and predictors of culture conversion at two months were evaluated.

RESULTS

Eighty seven (53.4%) out of 163 patients achieved culture conversion at two months. In a multivariate analysis lung cavitation at baseline chest X-ray (P = 0.006, OR = 0.349), resistance to ofloxacin (P = 0.041, OR = 0.193) and streptomycin (P = 0.017, OR = 0.295) had statistically significant (P<0.05) negative association with culture conversion at two months.

CONCLUSION

A reasonable proportion of patients achieved culture conversion at two months. Factors negatively associated with culture conversion at two months can be easily identified either before diagnosis or early in the course of MDR-TB treatment. This may help in better care of individual patients by identifying them early and treating them vigorously.

Thiazolopyridone ureas as DNA gyrase B inhibitors: optimization of antitubercular activity and efficacy

Scaffold hopping from the thiazolopyridine ureas led to thiazolopyridone ureas with potent antitubercular activity acting through inhibition of DNA GyrB ATPase activity. Structural diversity was introduced, by extension of substituents from the thiazolopyridone N-4 position, to access hydrophobic interactions in the ribose pocket of the ATP binding region of GyrB. Further optimization of hydrogen bond interactions with arginines in site-2 of GyrB active site pocket led to potent inhibition of the enzyme (IC50 2 nM) along with potent cellular activity (MIC=0.1 μM) against Mycobacterium tuberculosis (Mtb). Efficacy was demonstrated in an acute mouse model of tuberculosis on oral administration.