Case report: A 9-year systematic treatment failure of a pulmonary tuberculosis patient.

Objective: To explore the reasons of failure in a case of pulmonary tuberculosis (PTB) after 9 years systematic treatment. Methods: We extracted the patients' treatment history, drug susceptibility testing (DST), Computed tomography (CT) images, and sequenced the isolated strains by whole gene sequencing (WGS). Results: Although most results of the phenotypical DSTs were consistent with the genotype DST, the occurrence of gene resistance to amikacin (AMK), capreomycin (CAP), moxifloxacin (MFX) was earlier than the phenotypical DST. Based on the continuously reversed results of phenotypical DSTs, CT images in different stages and WGS, it can be confirmed that the patient was infected with two different strains of Mycobacterium tuberculosis (M.TB). Moreover, severe cavities may be another factor leading to treatment failure. Conclusion: Given the suggestive effect of genotype DST is earlier than the phenotypical DST, so genotype DST can play a better guiding role in patients with MDR-TB. Additionally, for patients who have not been cured for a long time, medication should be more cautious and the role of WGS in drug resistance surveillance should be fully utilized.

Accuracy of molecular drug susceptibility testing amongst tuberculosis patients in Karakalpakstan, Uzbekistan.

OBJECTIVES: In this retrospective study, we evaluated the diagnostic accuracy of molecular tests (MT) for the detection of DR-TB, compared to the gold standard liquid-based drug susceptibility testing (DST) in Karakalpakstan. METHODS: A total of 6670 specimens received in the Republican TB No 1 Hospital Laboratory of Karakalpakstan between January and July 2017 from new and retreatment patients were analysed. Samples were tested using Xpert MTB/RIF and line probe assays (LPA) for the detection of mutations associated with resistance. The sensitivity and specificity of MTs were calculated relative to results based on DST. RESULTS: The accuracy of MT for detection of rifampicin resistance was high, with sensitivity and specificity over 98%. However, we observed reduced sensitivity of LPA for detection of resistance; 86% for isoniazid (95% CI 82-90%), 86% for fluoroquinolones (95% CI 68-96%), 70% for capreomycin (95% CI 46-88%) and 23% for kanamycin (95% CI 13-35%). CONCLUSIONS: We show that MTs are a useful tool for rapid and safe diagnosis of DR-TB; however, clinicians should be aware of their limitations. Although detection of rifampicin resistance was highly accurate, our data suggest that resistance mutations circulating in the Republic of Karakalpakstan for other drugs were not detected by the methods used here. This merits further investigation.

Aminoglycosides and Capreomycin in the Treatment of Multidrug-resistant Tuberculosis: Individual Patient Data Meta-analysis of 12 030 Patients From 25 Countries, 2009-2016.

BACKGROUND: As new drugs are developed for multidrug-resistant tuberculosis (MDR-TB), the role of currently used drugs must be reevaluated. METHODS: We combined individual-level data on patients with pulmonary MDR-TB published during 2009-2016 from 25 countries. We compared patients receiving each of the injectable drugs and those receiving no injectable drugs. Analyses were based on patients whose isolates were susceptible to the drug they received. Using random-effects logistic regression with propensity score matching, we estimated the effect of each agent in terms of standardized treatment outcomes. RESULTS: More patients received kanamycin (n = 4330) and capreomycin (n = 2401) than amikacin (n = 2275) or streptomycin (n = 1554), opposite to their apparent effectiveness. Compared with kanamycin, amikacin was associated with 6 more cures per 100 patients (95% confidence interval [CI], 4-8), while streptomycin was associated with 7 (95% CI, 5-8) more cures and 5 (95% CI, 4-7) fewer deaths per 100 patients. Compared with capreomycin, amikacin was associated with 9 (95% CI, 6-11) more cures and 5 (95% CI, 2-8) fewer deaths per 100 patients, while streptomycin was associated with 10 (95% CI, 8-13) more cures and 10 (95% CI, 7-12) fewer deaths per 100 patients treated. In contrast to amikacin and streptomycin, patients treated with kanamycin or capreomycin did not fare better than patients treated with no injectable drugs. CONCLUSIONS: When aminoglycosides are used to treat MDR-TB and drug susceptibility test results support their use, streptomycin and amikacin, not kanamycin or capreomycin, are the drugs of choice.

Bedaquilina para pacientes com tuberculose resistentes à rifampicina, multirresistentes e extensivamente resistentes a medicamentos / Bedaquiline for tuberculosis-resistant patients rifampicin, multi-resistant and extensively resistant to medicines

INTRODUÇÃO: A tuberculose (TB), conhecida anteriormente como tísica, é uma doença que pode ser causada por sete espécies do gênero do complexo Mycobacterium sendo a mais importante, do ponto de vista de saúde pública, a M. tuberculosis. Globalmente cerca de 10 milhões de pessoas tiveram TB no ano de 2018. No Brasil, em 2018, foram diagnosticados 72.788 casos novos de TB o que representa uma incidência de 34,8 casos por 100 mil habitantes. A TB pode ser classificada como pulmonar e extrapulmonar, sendo a primeira forma mais prevalente. Além disso, a TB pode ser classificada conforme a resistência à medicamentos, tais como: RR-TB, MDR-TB e XDR-TB. PERGUNTA DE PESQUISA: A bedaquilina (BDQ) associada ao tratamento padrão para pacientes adultos com RR-TB, MDR-TB ou XDR-TB, é mais eficaz, efetiva e segura comparado ao tratamento padrão utilizado pelo SUS (levofloxacino, moxifloxacino, amicacina, capreomicina, etionamida, terizidona, linezolida, clofazimina, pirazinamida, etambutol, isoniazida, rifampicina e paraminossalicílico) ou placebo? TECNOLOGIA: Bedaquilina (Sirturo®). EVIDÊNCIAS CIENTÍFICAS: A revisão sistematizada recuperou nove estudos (uma revisão sistemática [RS] com meta-análise em rede [network meta-analysis - NMA], um ensaio clínico randomizado [ECR] com dois relatos e sete estudos de coorte [seis retrospectivas e uma prospectiva]). A RS, com NMA, avaliou a BDQ em comparação aos medicamentos delamanida, metronidazol, moxifloxacino e levofloxacino. A RS avaliou os desfechos conversão de cultura do escarro e aceitabilidade, e não foram verificados resultados estatisticamente significantes. Os estudos de coorte avaliaram a BDQ em comparação aos mais diversos tratamentos disponíveis para RR-TB, MDR-TB e XDR-TB. As coortes avaliaram os seguintes desfechos: sobrevida sucesso no tratamento, tratamento completo, cura, conversão da cultura do escarro e mortalidade. Os resultados não foram estatisticamente significantes na meta-análise de modelo de efeitos randomizados para todos os desfechos avaliados, porém os resultados dos efeitos fixos demostraram resultados estatisticamente significantes favorecendo o tratamento com BDQ em comparação ao tratamento sem BDQ. Vale salientar que foram realizadas análises de subgrupos com o ECR, TMC207, que avaliou eficácia e segurança da BDQ associado ao tratamento padrão em comparação ao grupo placebo associado ao tratamento padrão em até 120 semanas para os desfechos de conversão da cultura do escarro, cura e segurança (mortalidade), porém não mudaram a direção dos resultados nas duas modelagem da meta-análise. AVALIAÇÃO ECONÔMICA (AE): Os tratamentos com BDQ comparado aos tratamentos do SUS mostraram-se dominados na avaliação de custo-efetividade, para o desfecho paciente curado. Assim, os tratamentos do SUS para RR-TB, MDR-TB e XDR-TB dominaram todos os tratamentos com BDQ, ou seja, todos os tratamentos com BDQ foram menos efetivos e mais caros que os tratamentos do SUS para obter a cura dos indivíduos com RR-TB, MDR-TB e XDR-TB. AVALIAÇÃO DE IMPACTO ORÇAMENTÁRIO (AIO): A AIO, para os pacientes com RR-TB, variou entre um custo incremental R$ 936 mil no caso base a uma economia de -R$ 1 milhão ao final do quinto ano no cenário alternativo; para MDR-TB variou entre uma economia de -R$44 mil no caso base a um gasto de R$ 110 mil ao final do quinto ano no cenário alternativo; e para XDR-TB variou entre um custo incremental de R$ 188 mil no caso base a R$ 4 mil no cenário alternativo ao final do quinto ano. MONITORAMENTO DO HORIZONTE TECNOLÓGICO (MHT): Cinco medicamentos foram detectados no MHT para pacientes com MDR-TB e XDR-TB (canamicina, cicloserina, sutezolida, pretomanide e protionamida). CONSIDERAÇÕES FINAIS: Há resultados conflitantes nas evidências encontradas no relatório. O ECR, analisado como de alto risco de viés (Risk of Bias 2.0) mostrou que a BDQ associada ao tratamento padrão é eficaz em comparação ao grupo de tratamento placebo associado ao tratamento padrão, porém com maior número de mortes e episódios de náusea em comparação ao grupo de tratamento sem a BDQ. Os resultados da RS, com NMA, de qualidade moderada, não demonstraram diferenças estatisticamente significantes entre as tecnologias avaliadas. Os resultados das meta-análises dos estudos de coorte de baixa qualidade metodológica (Newcastle-Ottawa Scale), em combinação com o ECR da BDQ, foram demonstrados em efeitos fixos e randomizados. Os desfechos sucesso no tratamento, tratamento completo, cura, conversão da cultura do escarro e mortalidade não foram estatisticamente significantes no modelo de efeito randomizados na meta-análise. No entanto, foram estatisticamente significantes no modelo de efeito fixos da metaanálise, e favoreceram o tratamento com BDQ em comparação aos pacientes não tratados sem BDQ. A AE demonstrou que os tratamentos com BDQ foram dominados em relação aos tratamentos disponibilizados no SUS sem BDQ, para o desfecho paciente tratado, sendo, portanto, mais custosos e menos efetivos. A AIO, para pacientes com RR-TB, variou entre R$ 936 mil no caso base a uma economia de -R$ 1 milhão no cenário alternativo ao final do quinto ano, para MDRTB variou entre uma economia de -R$44 mil no caso base a um custo de R$ 110 mil ao final do quinto ano no cenário alternativo e para XDR-TB variou entre um custo adicional de R$ 188 mil no caso base a um custo adicional de R$ 4 mil ao final do quinto ano no cenário alternativo. RECOMENDAÇÃO PRELIMINAR DA CONITEC: A Conitec, em sua 87ª reunião ordinária, realizada nos dias 03 e 04 de junho de 2020, deliberou que a matéria fosse disponibilizada em consulta pública com recomendação preliminar favorável à incorporação no SUS da bedaquilina para pacientes com tuberculose resistente à rifampicina (RR-TB), a tuberculose multirresistente (MDR-TB) e para tuberculose extensivamente resistente a medicamentos (XDR-TB), condicionada ao monitoramento e apresentação dos dados de vida real, efetividade e segurança, da utilização da bedaquilina pela população brasileira e conforme critérios estabelecidos em protocolo do Ministério da Saúde. CONSULTA PÚBLICA: A Consulta Pública nº 24/2020 foi realizada entre os dias 22/06/2020 a 13/07/2020. Foram recebidas 66 contribuições no total, das quais 19 (29%) foram pelo formulário para contribuições técnico-científicas e 47 (71%) pelo formulário para contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Das 19 contribuições de cunho técnico-científico, 95% submeteram a contribuição com opinião concordando totalmente com a recomendação preliminar da comissão. Apenas uma contribuição discordou da recomendação preliminar da Conitec, mas foi uma contribuição equivocada e se tratava de outro tema de consulta pública, portanto, foi excluída da análise. Das 47 contribuições recebidas sobre experiência ou opinião, apenas 15 foram analisadas, pois 32 estavam em branco, se tratavam de outro tema ou foram preenchidas inadequadamente. As 15 contribuições remanescentes concordaram 100% com a decisão preliminar da comissão. Após a apreciação das contribuições encaminhadas na consulta pública nº 24/2020, o plenário da Conitec considerou que: I) Foi apresentado um novo preço de USD 340 da bedaquilina pela Johnson & Johnson, sendo proposto um desconto de 15% no preço utilizado no relatório de recomendação preliminar (USD 400); II) Foram enviadas novas estimativas de incidência para pacientes com tuberculose multirresistente, bem como evidência de possíveis limitações na análise de impacto orçamentário; III) A nova análise de impacto orçamentário, utilizando os novos parâmetros enviados na consulta pública, aponta para economia de recursos na população com tuberculose multirresistente e um custo incremental com tuberculose resistente à rifampicina e tuberculose extensivamente resistente no cenário sem taxa de difusão gradual da bedaquilina (100% no primeiro ano de incorporação). No entanto, ao adotarmos o cenário com taxa difusão gradual da bedaquilina, 30% no primeiro ano de incorporação a 70% no quinto ano, os resultados mudam e proporcionam economia de recursos para pacientes com tuberculose resistente à rifampicina e um custo incremental para pacientes com tuberculose multirresistente e tuberculose extensivamente resistente. RECOMENDAÇÃO FINAL DA CONITEC: Os membros da Conitec presentes na 89ª reunião ordinária, no dia 05 de agosto de 2020, deliberaram por unanimidade recomendar a incorporação da bedaquilina para pacientes com tuberculose resistentes à rifampicina, multirresistentes e extensivamente resistente a medicamentos, condicionado a apresentação de dados de vida real e conforme preconizado pelo Ministério da Saúde. Foi assinado o Registro de Deliberação nº 538/2020. DECISÃO: Incorporar a bedaquilina para pacientes com tuberculose resistentes à rifampicina, multirresistentes e extensivamente resistente a medicamentos, condicionado a apresentação de dados de vida real e conforme preconizado pelo Ministério da Saúde, no âmbito do Sistema Único de Saúde - SUS, conforme Portaria nº 36, publicada no Diário Oficial da União nº 168, seção 1, página 77, em 01 de setembro de 2020.

Tetany in an Extensively Drug Resistant Tuberculosis (XDR-TB) Patient Treated with Capreomycin.

Gross electrolytes disturbances including hypokalemia, hypomagnesaemia, and hypocalcaemia have been reported in tuberculosis patients who have been treated with capreomycin.1-3 Capreomycin is recommended in the treatment of M. tuberculosis isolates resistant to kanamycin at baseline in multi drug resistant tuberculosis patients (MDR - TB) and treatment of extensively drug resistant tuberculosis (XDR-TB) under programmatic management of drug resistant tuberculosis (PMDT) in India.4 We report a case of tetany in a extensively drug resistant tuberculosis (XDR-TB) patient treated with capreomycin. She developed hypokalemia after 7 weeks of administration of injection capreomycin intramuscularly daily in dose of 750 mg. Hypokalemia was refractory to intravenous potassium replacement therapy. At 12 weeks during the treatment she developed tetany and hypocalcaemia. Hypomagnesaemia was also associated with hypocalcaemia and hypokalemia. Normal level of serum potassium and calcium were achieved with correction of hypomagnesaemia.

Synergistic activities of clofazimine with moxifloxacin or capreomycin against Mycobacterium tuberculosis in China.

Clofazimine (CFZ) is a promising candidate drug for use in the management of multidrug-resistant tuberculosis (MDR-TB) patients. In this study, the minimum inhibitory concentration (MIC) method and checkerboard method were used to investigate potential synergies between CFZ and moxifloxacin (MOX) or capreomycin (CAP). Thirty Mycobacterium tuberculosis strains were collected, including 13 MDR strains, 2 extensively drug-resistant (XDR) strains, 3 pan-sensitive strains and 12 strains resistant to other drugs. When the minimum fractional inhibitory concentration indexes (FICIs) were calculated, synergy was found in 21 (70.00%) M. tuberculosis strains against the CFZ/CAP combination and 29 (96.67%) against the CFZ/MOX combination. When the maximum FICIs were calculated, 10 of 15 MDR/XDR strains and 2 of 15 other drug-resistant or pan-sensitive strains showed antagonism against the CFZ/CAP combination, whilst 8 of 15 MDR/XDR strains and 1 of 15 other drug-resistant or pan-sensitive strains showed antagonism against the CFZ/MOX combination, respectively. In conclusion, these findings demonstrate that the combination of CFZ and MOX shows better synergism than the combination of CFZ and CAP. The MDR/XDR isolates are more likely to show antagonism than the other drug-resistant or pan-sensitive strains in both the CFZ/MOX and CFZ/CAP combinations. CFZ in combination with MOX may be a promising drug regimen for the treatment of MDR-TB, particularly for susceptible M. tuberculosis infections.

Treatment correlates of successful outcomes in pulmonary multidrug-resistant tuberculosis: an individual patient data meta-analysis.

BACKGROUND: Treatment outcomes for multidrug-resistant tuberculosis remain poor. We aimed to estimate the association of treatment success and death with the use of individual drugs, and the optimal number and duration of treatment with those drugs in patients with multidrug-resistant tuberculosis. METHODS: In this individual patient data meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library to identify potentially eligible observational and experimental studies published between Jan 1, 2009, and April 30, 2016. We also searched reference lists from all systematic reviews of treatment of multidrug-resistant tuberculosis published since 2009. To be eligible, studies had to report original results, with end of treatment outcomes (treatment completion [success], failure, or relapse) in cohorts of at least 25 adults (aged >18 years). We used anonymised individual patient data from eligible studies, provided by study investigators, regarding clinical characteristics, treatment, and outcomes. Using propensity score-matched generalised mixed effects logistic, or linear regression, we calculated adjusted odds ratios and adjusted risk differences for success or death during treatment, for specific drugs currently used to treat multidrug-resistant tuberculosis, as well as the number of drugs used and treatment duration. FINDINGS: Of 12 030 patients from 25 countries in 50 studies, 7346 (61%) had treatment success, 1017 (8%) had failure or relapse, and 1729 (14%) died. Compared with failure or relapse, treatment success was positively associated with the use of linezolid (adjusted risk difference 0·15, 95% CI 0·11 to 0·18), levofloxacin (0·15, 0·13 to 0·18), carbapenems (0·14, 0·06 to 0·21), moxifloxacin (0·11, 0·08 to 0·14), bedaquiline (0·10, 0·05 to 0·14), and clofazimine (0·06, 0·01 to 0·10). There was a significant association between reduced mortality and use of linezolid (-0·20, -0·23 to -0·16), levofloxacin (-0·06, -0·09 to -0·04), moxifloxacin (-0·07, -0·10 to -0·04), or bedaquiline (-0·14, -0·19 to -0·10). Compared with regimens without any injectable drug, amikacin provided modest benefits, but kanamycin and capreomycin were associated with worse outcomes. The remaining drugs were associated with slight or no improvements in outcomes. Treatment outcomes were significantly worse for most drugs if they were used despite in-vitro resistance. The optimal number of effective drugs seemed to be five in the initial phase, and four in the continuation phase. In these adjusted analyses, heterogeneity, based on a simulated I2 method, was high for approximately half the estimates for specific drugs, although relatively low for number of drugs and durations analyses. INTERPRETATION: Although inferences are limited by the observational nature of these data, treatment outcomes were significantly better with use of linezolid, later generation fluoroquinolones, bedaquiline, clofazimine, and carbapenems for treatment of multidrug-resistant tuberculosis. These findings emphasise the need for trials to ascertain the optimal combination and duration of these drugs for treatment of this condition. FUNDING: American Thoracic Society, Canadian Institutes of Health Research, US Centers for Disease Control and Prevention, European Respiratory Society, Infectious Diseases Society of America.

First Insight Into the Fluoroquinolone and Aminoglycoside Resistance of Multidrug-Resistant Mycobacterium tuberculosis in Saudi Arabia.

AbstractIn Saudi Arabia, there were no nationwide screening studies conducted so far to determine the aminoglycoside and fluoroquinolone resistance among multidrug-resistant tuberculosis (MDR-TB) isolates. Therefore, as the first attempt in the country, a retrospective analysis has been conducted on a nationwide collection of 2,956 M. tuberculosis clinical isolates screened with phenotypic drug susceptibility testing to define MDR-TB. Enrolled MDR-TB isolates were subjected to second-line drug susceptibility testing, detection of mutations conferring resistance to aminoglycosides and fluoroquinolone, followed by 24-loci mycobacterial interspersed repetitive unit-variable number of tandem repeat typing and spoligotyping. Overall, 83 isolates were identified as MDR-TB, and 13 (15.7%) isolates showed resistance to second-line drugs. Moxifloxacin (low level) showed higher resistant rates (10.8%) followed by ofloxacin (7.2%), capreomycin (3.6%), kanamycin (3.6%), and amikacin (2.4%). Overall fluoroquinolone resistance was 12%, whereas aminoglycoside resistance was 7.2%. Predominant mutations conferring resistance to fluoroquinolone were found in gyrA A90V and D94G, whereas aminoglycoside resistance was observed only with rrs gene A1401G mutation. The corresponding strain lineages predominated with Indo-Oceanic and East-African Indian origin. Interestingly, none of the isolates with second-line drug resistance was defined as extensively drug-resistant TB (XDR-TB). Surprisingly, many isolates (50.6%) were panresistant to first-line drugs. Saudi Arabia faces considerable burden of fluoroquinolone- and aminoglycoside-resistant MDR-TB. Higher incidence of panresistant MDR-TB reveals a threat for the emergence of XDR-TB strains in the near future.

Interactions of linezolid and second-line anti-tuberculosis agents against multidrug-resistant Mycobacterium tuberculosis in vitro and in vivo.

OBJECTIVES: The objectives of this study were to evaluate the interactions between linezolid (LZD) and second-line anti-tuberculosis (TB) agents in susceptible and multidrug-resistant (MDR) TB in vitro, and to validate the in vitro results in a murine TB model. METHODS: The minimum inhibitory concentrations of LZD and seven second-line anti-TB drugs against H37Rv and three multidrug-resistant clinical isolates were determined by Alamar Blue assay, and the interaction patterns of LZD and the seven second-line anti-TB agents against the four isolates were studied using a dynamic checkerboard method. The activities of these combinations against Mycobacterium tuberculosis were evaluated in a murine model of TB. RESULTS: The combination of LZD + capreomycin exhibited partial synergism for three of four isolates, LZD + para-aminosalicylic acid exhibited partial synergism for two of four isolates, and LZD + levofloxacin and LZD + amikacin exhibited partial synergism for one of four isolates; all other combinations showed indifference or an additive effect in vitro. The activities of six combinations and the standard regimen rifampicin + isoniazid + pyrazinamide were investigated in a murine model of TB (infection with H37Rv). Significant reductions in colony-forming units (CFU) were found in LZD + capreomycin and LZD + clofazimine groups when the CFU in the lungs on day 0 (the day of beginning treatment) was compared with the CFU in the lungs after 2 months of treatment. CONCLUSIONS: These combinations of LZD and second-line anti-TB drugs were all active against MDR-TB with indifference or an additive effect, except LZD + capreomycin, which showed partial synergy.

Disparities in capreomycin resistance levels associated with the rrs A1401G mutation in clinical isolates of Mycobacterium tuberculosis.

As the prevalence of multidrug-resistant and extensively drug-resistant tuberculosis strains continues to rise, so does the need to develop accurate and rapid molecular tests to complement time-consuming growth-based drug susceptibility testing. Performance of molecular methods relies on the association of specific mutations with phenotypic drug resistance and while considerable progress has been made for resistance detection of first-line antituberculosis drugs, rapid detection of resistance for second-line drugs lags behind. The rrs A1401G allele is considered a strong predictor of cross-resistance between the three second-line injectable drugs, capreomycin (CAP), kanamycin, and amikacin. However, discordance is often observed between the rrs A1401G mutation and CAP resistance, with up to 40% of rrs A1401G mutants being classified as CAP susceptible. We measured the MICs to CAP in 53 clinical isolates harboring the rrs A1401G mutation and found that the CAP MICs ranged from 8 µg/ml to 40 µg/ml. These results were drastically different from engineered A1401G mutants generated in isogenic Mycobacterium tuberculosis, which exclusively exhibited high-level CAP MICs of 40 µg/ml. These data support the results of prior studies, which suggest that the critical concentration of CAP (10 µg/ml) used to determine resistance by indirect agar proportion may be too high to detect all CAP-resistant strains and suggest that a larger percentage of resistant isolates could be identified by lowering the critical concentration. These data also suggest that differences in resistance levels among clinical isolates are possibly due to second site or compensatory mutations located elsewhere in the genome.

Second-line drug susceptibility breakpoints for Mycobacterium tuberculosis using the MODS assay.

OBJECTIVE: To establish breakpoint concentrations for the fluoroquinolones (moxifloxacin [MFX] and ofloxacin [OFX]) and injectable second-line drugs (amikacin [AMK], kanamycin [KM] and capreomycin [CPM]) using the microscopic observation drug susceptibility (MODS) assay. SETTING: A multinational study conducted between February 2011 and August 2012 in Peru, India, Moldova and South Africa. DESIGN: In the first phase, breakpoints for the fluoroquinolones and injectable second-line drugs (n = 58) were determined. In the second phase, MODS second-line drug susceptibility testing (DST) as an indirect test was compared to MGIT™ DST (n = 89). In the third (n = 30) and fourth (n = 156) phases, we determined the reproducibility and concordance of MODS second-line DST directly from sputum. RESULTS: Breakpoints for MFX (0.5 µg/ml), OFX (1 µg/ml), AMK (2 µg/ml), KM (5 µg/ml) and CPM (2.5 µg/ml) were determined. In all phases, MODS results were highly concordant with MGIT DST. The few discrepancies suggest that the MODS breakpoint concentrations for some drugs may be too low. CONCLUSION: MODS second-line DST yielded comparable results to MGIT second-line DST, and is thus a promising alternative. Further studies are needed to confirm the accuracy of the drug breakpoints and the reliability of MODS second-line DST as a direct test.

Performance of the MTBDRsl assay in Georgia.

SETTING: The country of Georgia has a high burden of multi- (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB). OBJECTIVE: To assess the performance of the GenoType® MTBDRsl assay in the detection of resistance to kanamycin (KM), capreomycin (CPM) and ofloxacin (OFX), and of XDR-TB. DESIGN: Consecutive acid-fast bacilli smear-positive sputum specimens identified as MDR-TB using the MTBDRplus test were evaluated with the MTBDRsl assay and conventional second-line drug susceptibility testing (DST). RESULTS: Among 159 specimens, amplification was adequate in 154 (97%), including 9 of 9 culture-negative and 2 of 3 contaminated specimens. Second-line DST revealed that 17 (12%) Mycobacterium tuberculosis isolates were XDR-TB. Compared to DST, the MTBDRsl had 41% sensitivity and 98% specificity in detecting XDR-TB and 81% sensitivity and 99% specificity in detecting OFX resistance. Sensitivity was low in detecting resistance to KM (29%) and CPM (57%), while specificity was respectively 99% and 94%. Median times from sputum collection to second-line DST and MTBDRsl results were 70-104 vs. 10 days. CONCLUSION: Although the MTBDRsl assay had a rapid turnaround time, detection of second-line drug resistance was poor compared to DST. Further genetic mutations associated with resistance to second-line drugs should be included in the assay to improve test performance and clinical utility.

Salvage therapy for multidrug-resistant tuberculosis.

Treatment of multidrug-resistant tuberculosis (MDR-TB), defined as Mycobacterium tuberculosis resistant to both isoniazid and rifampicin, is challenging under the best of circumstances, and particularly in resource-limited settings. For patients who remain persistently sputum-culture-positive despite therapy with second-line TB drugs, treatment options are limited, especially if disease is too advanced for resective surgery. Salvage therapy refers to the design of a regimen combining new and previously used drugs in a final effort to attain sputum conversion before declaring treatment to have failed. We retrospectively evaluated the outcomes of salvage therapy in 213 Peruvian patients. Salvage regimens included a median of two new drugs (range 1-6) and nine (range 5-13) total (new plus previously used) drugs. The most frequently used new drug was moxifloxacin, followed by capreomycin, amoxicillin-clavulanate, kanamycin and clarithromycin. Culture conversion occurred in 65 (30.5%) patients. Salvage regimens that included moxifloxacin were significantly more likely to be followed by culture conversion (OR 2.2; p 0.02). Later-generation fluoroquinolones such as moxifloxacin should be used in salvage therapy but also in the initial treatment of MDR-TB, if the best clinical strategy is to use the most effective drugs when the patient has the best chance for cure. New TB drugs are most likely to be initially used in salvage patients, in conditions similar to those described here. Close bacteriological monitoring of these patients will be essential, as useful information about the best way to use these new drugs can be gained from analysis of salvage therapy cohorts.

First proficiency testing of second-line anti-tuberculosis drug susceptibility testing in 12 provinces of China.

OBJECTIVE: To evaluate the performance of drug susceptibility testing (DST) against the main second-line (SL) anti-tuberculosis drugs in tuberculosis (TB) laboratories in China. METHOD: The supranational TB reference laboratory issued 30 Mycobacterium tuberculosis isolates to the participating laboratories. Each participating laboratory performed DST against kanamycin (KM), amikacin (AMK), capreomycin (CPM) and ofloxacin (OFX) using the proportion method in Löwenstein-Jensen medium per World Health Organization recommendations. Reported results were checked and compared with the judicial results. RESULT: The main performance indicators for the four anti-tuberculosis drugs evaluated (KM, AMK, CPM, OFX) were as follows: accordance rates: 91.62%, 99.16%, 96.93% and 96.37%; reproducibility: 99.16%, 99.16%, 94.96% and 94.12%; specificity: 99.12%, 99.64%, 98.00% and 98.41%; sensitivity: 78.03%, 97.62%, 94.44% and 91.51%. The accordance rates and sensitivity values of the four drugs showed statistically significant differences, while specificities showed no significant differences. CONCLUSION: Eight (66.7%) participating laboratories met the set requirement criteria; however, DST in four (33.3%) laboratories requires greater attention. Of the four drugs tested, the results for KM were lower than those for the other drugs. External quality assessment can lead to effective evaluation of laboratory performance in SL DST.

Capreomycin supergenerics for pulmonary tuberculosis treatment: preparation, in vitro, and in vivo characterization.

The pulmonary route is one of the main strategies investigated to improve tuberculosis therapy. The aim of this study was to develop a simple and scalable method to produce capreomycin inhalable powders to use as supergeneric. In vitro antimycobacterial activity and in vivo acute toxicity were assessed using agar proportion susceptibility test on Mycobacterium tuberculosis and chicken chorioallantoic membrane assay, respectively. Capreomycin and three different hydrophobic counterions, namely oleate, linoleate, and linolenate, were combined in solution to obtain hydrophobic ion-pairs that were successively spray-dried. Ion-pairing efficiency was influenced by the spray-dryer employed to produce the powder. In the case of capreomycin oleate, both instruments, mini and nano spray-dryer, were suitable to maintain a high ion-paired content, while for capreomycin linoleate and linolenate, mini spray-dryer was the most appropriate instrument. The three formulations showed morphology and particle sizes potentially suitable for inhalation. Capreomycin oleate and linoleate showed the same efficacy of capreomycin sulfate against M. tuberculosis, while capreomycin linolenate showed a reduced efficacy, even though strain growth was inhibited at 10(-4) mycobacterial inoculum. In vivo acute toxicity studies evidenced the lowest toxic potential for capreomycin oleate when compared to the single components or the other two salts. Overall, capreomycin oleate seems to possess the most promising characteristics to be used as supergenerics in pulmonary tuberculosis treatment.

Evaluation of the GenoType® MTBDRsl assay for susceptibility testing of second-line anti-tuberculosis drugs.

BACKGROUND: The GenoType® MTBDRsl assay is a new rapid assay for the detection of resistance to second-line anti-tuberculosis drugs. OBJECTIVE: To evaluate the MTBDRsl assay on 342 multidrug-resistant tuberculosis isolates for resistance to ofloxacin (OFX), kanamycin (KM), capreomycin (CPM) and ethambutol (EMB), to compare the results to the agar proportion method, and to test discrepant results using DNA sequencing. RESULT: The sensitivity and specificity of the MTBDRsl assay were respectively 70.3% and 97.7% for OFX, 25.0% and 98.7% for KM, 21.2% and 98.7% for CPM and 56.3% and 56.0% for EMB. DNA sequencing identified mutations that were not detected by the MTBDRsl assay. The 8/11 phenotypically OFX-resistant isolates had mutations in gyrA (2/8 had an additional mutation in the gyrB gene), 1/11 had mutations only in the gyrB gene, 6/21 phenotypically KM-resistant isolates had mutations in the rrs gene, and 7/26 and 20/26 phenotypically CPM-resistant isolates had mutations in the rrs and tlyA genes. CONCLUSION: The MTBDRsl assay showed lower sensitivity than previous studies. The assay performed favourably for OFX; however, it was less sensitive in the detection of KM/CPM resistance and demonstrated low sensitivity and specificity for EMB resistance. It is recommended that the MTBDRsl assay include additional genes to achieve better sensitivity for all the drugs tested.

Extensively drug resistance (XDR) tb is not always fatal.

The chance of incidence of XDR TB is on the rise due to improper use of second line anti-tubercular drugs. XDR-TB is very difficult to treat successfully and is often referred to as "virtually untreatable form of TB". We herein report a case of XDR TB confirmed by bacteriological examination in a WHO recognised laboratory who after 12 months of regular treatment improved both clinically and radiologically with sputum smear conversion. To the best of our knowledge, there has been no previous report of any similar case in literature.

[Tuberculosis caused by XDR resistant Mycobacterium tuberculosis in Poland. Microbiological and molecular analysis]. / Gruzlica wywolana pratkami o opornosci XDR w Polsce. Badania mikrobiologiczne i molekularne.

INTRODUCTION: The retrospective analysis of frequency of drug resistant tuberculosis XDR (XDR = MDR + resistance to: fluoroquinolones + amikacin and/or capreomycin) in Poland have been tested. MATERIAL AND METHODS: Pattern of resistance to first, second and third line drugs has been tested among new and treated patients. The total number of 10 913 Mycobacterium tuberculosis strains isolated from the same number of the patients surveyed in 1997-2004 in WHO programme Drug resistance surveillance countrywide study. RESULTS: One HIV-negative patient (43 years old men) was infected by XDR (0,4% among new and treated MDR cases). Molecular analysis of the XDR strain by spoligotyping has been shown the T11558 cluster. Three others tuberculosis patients living in the same region of Poland excreted the Mycobacterium tuberculosis strains belonged to the same T11558 cluster, but they had not pattern of XDR resistance. In the same T11558 molecular cluster 13/15 - 87% strains have been isolated from polish patients. CONCLUSIONS: In Poland Mycobacterium tuberculosis resistance to fluoroquinolones, capreomycin and amikacine among MDR strains has been observed very rarely.

Hepatotoxicity associated with acetaminophen usage in patients receiving multiple drug therapy for tuberculosis.

We report three patients who experienced hepatotoxic reactions in association with acetaminophen ingestion while undergoing treatment for active tuberculosis with isoniazid, rifampin, and other agents. All were young adult women. One patient intentionally took a large amount of acetaminophen and had typical signs and symptoms of acetaminophen overdosage; another took acetaminophen in combination form for a minor upper respiratory illness. She experienced no symptoms. The remaining patient took acetaminophen to ameliorate the symptoms of fever and malaise that were subsequently attributed to tuberculosis. She had the rapid onset of signs and symptoms of isoniazid hepatotoxicity. The patterns of liver function abnormalities were similar: each patient experienced pronounced serum elevations of hepatocellular enzymes with at most only modest rises in those of bilirubin. All antituberculous drugs were withheld until symptoms resolved and laboratory values became normal; then treatment for tuberculosis was resumed without isoniazid and was successfully completed in all three patients. These cases plus similar reports in the literature suggest that isoniazid or rifampin, or both, may potentiate the hepatotoxicity of acetaminophen, perhaps by induction of cytochrome P450 isozymes that oxidize acetaminophen to its toxic metabolites.