Frequency of first and second-line drug resistance-associated mutations among resistant Mycobacterium tuberculosis clinical isolates from São Paulo, Brazil

BACKGROUND Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis, and the number of new cases of multidrug resistant TB (MDR-TB), pre extensively drug-resistant TB (pre-XDR-TB) and extensively drug-resistant TB (XDR-TB) has increased considerably worldwide. OBJECTIVES Herein, using 156 M. tuberculosis isolates from 106 patients previously classified as MDR or pre-XDR or XDR isolates, we investigated the genetic mutation profiles associated with phenotypic resistances in patients with MDR-TB, pre-XDR-TB and XDR-TB, treatment outcomes and resistance evolution. METHODS Molecular analyses were performed by partial sequencing of the rpoB, katG, gyrA, gyrB, rrs genes and analysis of the fabG-inhA promoter region. Clinical, epidemiologic and demographic data were obtained from the TB Notification database system of São Paulo (TB-WEB) and the Information System for Special Tuberculosis Treatments (SITE-TB). FINDINGS Drug resistance was attributed to previously known mutations and a novel Asp449Val mutation in gyrB was observed in four isolates from the same patient. Ten patients had more than one isolate evaluated and eight of these patients displayed resistance progression. MAIN CONCLUSIONS The present study is the first to report the frequency of mutations related to second-line drug resistance in MDR-TB, pre-XDR-TB and XDR-TB isolates. The results could lead to the improvement of available technologies for the rapid detection of drug resistant TB.

Aspectos clínicos e tratamento de pacientes com tuberculose ocular presumida em centro de referência de São Paulo, Brasil. Estudo retrospectivo / Clinical description and treatment of patients with presumed ocular tuberculosis in São Paulo, Brazil. Retrospective study

Resumo Objetivo: Descrever aspectos clínicos e esquema terapêutico dos pacientes com tuberculose ocular presumida tratados em um centro de referência em tuberculose de São Paulo. Métodos: Estudo retrospectivo descritivo. O teste exato de Fisher foi realizado quando apropriado. Resultados: A queixa mais comum foi baixa acuidade visual (83,1%), seguida por dor ocular generalizada (25,3%) e visão turva (22,8%). A uveíte posterior foi a apresentação mais comum (35,7%). O tratamento consistiu no esquema atualmente recomendado de rifampicina, isoniazida, pirazinamida e etambutol (RHZE). A prednisona oral foi incluída no tratamento de 37 pacientes, para tratamento da inflamação aguda, embora não tenha diminuído a prevalência de complicações crônicas, em comparação com a recuperação completa (p = 0,1). O diagnóstico precoce (<70 dias) foi associado a maiores taxas de recuperação total (p = 0,005). Não houve significância estatística quando se comparou a terapia de 6 a 9 meses (p = 0,7). Conclusão: A uveíte tuberculosa pode ser tratada por uma terapia com duração de seis meses. Um breve curso de esteroides melhora os sintomas agudos, embora não reduza as complicações a longo prazo.

Abstract Purpose: To analyze and describe the therapy used in presumed ocular tuberculosis in a referral center in São Paulo, Brazil. Methods: Retrospective, descriptive study. Fisher's exact test was performed when appropriate. Results: The most common complaint was low visual acuity (83.1%), followed by generalized ocular pain (25.3%) and blurred vision (22.8%). Posterior uveitis was the most common presentation (35.7%). Treatment consisted of the currently recommended association of rifampin, isoniazid, pyrazinamide, ethambutol (RHZE) regimen. Oral prednisone was included in the treatment of 37 patients for acute inflammation, although it did not significantly decrease the prevalence of chronic complications compared to full recovery (p = 0,1). Early diagnosis (< 70 days) was associated with higher rates of full recovery (p = 0.005). No statistical significance was observed when comparing 6 to 9-month therapy (p = 0.7). Conclusion: Tuberculous uveitis can be treated with a 6-month duration RHZE therapy. A brief course of steroids may improve acute symptoms, although it did not reduce long-term disabilities.

Abandono del tratamiento en tuberculosis multirresistente: factores asociados en una región con alta carga de la enfermedad en Perú / Abandonment of therapy in multidrug-resistant tuberculosis: Associated factors in a region with a high burden of the disease in Perú

Resumen Introducción. En la tuberculosis multirresistente, el abandono del tratamiento constituye un grave problema de salud pública que afecta la calidad de vida de los pacientes, sus familias y la comunidad. El enfrentarlo supone una carga para los sistemas sanitarios debido a que provoca fuentes de transmisión libre en la comunidad e incrementa la prevalencia y la mortalidad. De ahí, la necesidad de investigar los factores asociados con esta situación. Objetivo. Determinar los factores de riesgo asociados con el abandono del tratamiento en pacientes con tuberculosis multirresistente en la región de Callao (Perú). Materiales y métodos. Se hizo un estudio analítico de casos y controles (80 casos y 180 controles) en tratamiento entre el 1° enero del 2010 y el 31 diciembre del 2012. Los factores se determinaron mediante regresión logística, y se calcularon los odds ratios (OR) y los intervalos de confianza (IC) del 95 %. Resultados. En el análisis multivariado se determinaron los siguientes factores de riesgo: no tener conocimiento de la enfermedad (OR=23,10; IC95%: 3,6-36,79; p=0,002); no creer en la curación (OR=117,34; IC95%: 13,57-124,6; p=0,000); no tener apoyo social (OR=19,16; IC95%: 1,32-27,77; p=0,030); no considerar adecuado el horario de atención (OR=78,13; IC95%: 4,84-125,97; p=0,002), y no recibir los resultados de laboratorio (OR=46,13; IC95%: 2,85-74,77; p=0,007). Conclusión. Los servicios de salud deben esforzarse en la determinación precoz de las condiciones que podrían convertirse en factores de riesgo, lo cual ayudaría a implementar preventivamente intervenciones efectivas, rápidas y de alto impacto.

Abstract Introduction: In the context of multidrug-resistant tuberculosis, abandonment of therapy represents a serious public health problem that affects the quality of life of patients, families, and communities. Managing this phenomenon places a burden on health systems since it causes free sources of transmission in the community, thereby increasing prevalence and mortality. Thus, there is a need to study factors associated with this problem. Objective: This study sought to identify risk factors associated with the abandonment of therapy by patients with multidrug-resistant tuberculosis in the Peruvian region of Callao. Materials and methods: We conducted an analytical case-control study (cases=80; controls=180) in patients under treatment from January 1st, 2010, to December 31, 2012. Risk factors were identified using logistic regression; odds ratios (OR) and 95% confidence intervals (CI) were calculated. Results: The multivariate analysis identified the following risk factors: Being unaware of the disease (OR=23.10; 95% CI 3.6-36.79; p=0.002); not believing in healing (OR=117.34; 95% CI 13.57-124.6; p=0.000); not having social support (OR=19.16; 95% CI 1.32-27.77; p=0.030); considering the hours of attention to be inadequate (OR=78.13; 95% CI 4.84-125.97; p=0.002), and not receiving laboratory reports (OR=46.13; 95% CI 2.85-74.77; p=0.007). Conclusion: Health services must focus on the early detection of conditions that may represent risk factors to proactively implement effective, rapid and high-impact interventions.

Genotipificación de aislamientos del complejo Mycobacterium tuberculosis mediante MIRU-VNTR, Cali, Colombia, 2013-2015 / MIRU-VNTR genotyping of Mycobacterium tuberculosis in a population of patients in Cali, Colombia, 2013-2015

Resumen Introducción. La tuberculosis continúa siendo uno de los problemas de salud más importantes a nivel mundial y, con la infección por el virus de la inmunodeficiencia humana (HIV), constituye la principal causa de muerte por infecciones. En el 2016, se notificaron 6,3 millones de casos nuevos de la enfermedad. Objetivo. Describir los patrones genéticos determinados mediante la genotipificación del número variable de repeticiones en tándem de unidades repetitivas interespaciadas de micobacterias (Mycobacterial Interspersed Repetitive Units - Variable Number of Tandem Repeats, MIRU-VNTR) en la población de estudio y compararlos con los hallados en otros estudios locales e internacionales. Materiales y métodos. Mediante MIRU-VNTR, entre el 2013 y el 2015 se hizo la genotipificación de 105 muestras de ADN extraídas del esputo o de aislamientos en cultivo de M. tuberculosis provenientes de pacientes residentes en Cali con diagnóstico de tuberculosis pulmonar. La amplificación de 24 loci MIRU-VNTR se hizo por medio de la reacción en cadena de la polimerasa (PCR). Los amplicones resultantes se visualizaron por electroforesis en geles de agarosa (2 %) teñidos con SYBR Safe™. La asignación de los alelos se hizo con un análisis gráfico con el programa GelAnalyzer 2010. Los resultados obtenidos se analizaron con el algoritmo UPGMA y se compararon con las bases de datos internacionales MIRU-VNTRplus y SITVITWEB. Resultados. Se genotipificaron por completo 62 de las muestras y se obtuvieron 58 perfiles diferentes de MIRU-VNTR. Al comparar con las bases de datos internacionales, su distribución por linajes fue la siguiente: 54,8 % para el LAM, 25,8 % para el Haarlem, 14,5 % para el S, 3,2 % para el Beijing y 1,6 % para el Cameroon. Los patrones MIRU-VNTR correspondieron a 20 tipos internacionales de MIRU (MIRU International Types, MIT) diferentes, y los más frecuentes fueron el MIT 190 y el MIT 110, con 22,6 y 6,5 %, respectivamente. Conclusión. Estos resultados confirmaron hallazgos previos sobre el predominio de los linajes LAM y Haarlem en la ciudad y la presencia de los MIT encontrados en otra ciudad de Colombia.

Abstract Introduction: Tuberculosis continues to be one of the main public health problems in the world. Together with the HIV infection, it is one of the main causes of death due to infections worldwide. In 2016, 6.3 million new cases of the disease were reported. Objective: To describe the genetic patterns determined by genotyping using variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR) in the study population and compare them with other studies carried out in Cali, Colombia, and the world. Materials and methods: We genotyped a total of 105 DNA samples extracted from sputum or culture isolates of the Mycobacterium tuberculosis complex, which were obtained from pulmonary tuberculosis diagnosed patients over the period 2013-2015, in Cali. We performed PCR amplification of 24 loci by MIRU-VNTR on the DNA extracted from the samples. The amplicons were visualized in agarose gel electrophoresis (2%) with SYBR Safe™ staining. Then, the alleles were designated by graphical analysis using the GelAnalyzer 2010 software. These results were analyzed using the UPGMA logarithm and compared with the registers from the MIRU-VNTR plus and SITVITWEB databases. Results: We genotyped 62 of the samples completely and we obtained 58 different MIRU-VNTR profiles. By comparing with the international databases, we determined the following distributions per lineage: LAM, 54.8%; Haarlem,25.8%; S, 14.5%; Beijing, 3.2%, and Cameroon, 1.6%. The MIRU-VNTR patterns corresponded to 17 different MITs; the most frequent were MIT 190 and MIT 110, with 22.6% and 6.5%, respectively. Conclusions: These results demonstrated previous observations about the predominance of the LAM and Haarlem lineages in the city, and the presence of the MITs found in another city of Colombia.

Drug-resistant tuberculosis in subjects included in the Second National Survey on Antituberculosis Drug Resistance in Porto Alegre, Brazil / Tuberculose resistente em pacientes incluídos no II Inquérito Nacional de Resistência aos Fármacos Antituberculose realizado em Porto Alegre, Brasil

OBJECTIVE: To describe the prevalence of multidrug-resistant tuberculosis (MDR-TB) among tuberculosis patients in a major Brazilian city, evaluated via the Second National Survey on Antituberculosis Drug Resistance, as well as the social, demographic, and clinical characteristics of those patients. METHODS: Clinical samples were collected from tuberculosis patients seen between 2006 to 2007 at three hospitals and five primary health care clinics participating in the survey in the city of Porto Alegre, Brazil. The samples were subjected to drug susceptibility testing. The species of mycobacteria was confirmed using biochemical methods. RESULTS: Of the 299 patients included, 221 (73.9%) were men and 77 (27.3%) had a history of tuberculosis. The mean age was 36 years. Of the 252 patients who underwent HIV testing, 66 (26.2%) tested positive. The prevalence of MDR-TB in the sample as a whole was 4.7% (95% CI: 2.3-7.1), whereas it was 2.2% (95% CI: 0.3-4.2) among the new cases of tuberculosis and 12.0% (95% CI: 4.5-19.5) among the patients with a history of tuberculosis treatment. The multivariate analysis showed that a history of tuberculosis and a longer time to diagnosis were both associated with MDR-TB. CONCLUSIONS: If our results are corroborated by other studies conducted in Brazil, a history of tuberculosis treatment and a longer time to diagnosis could be used as predictors of MDR-TB. .

OBJETIVO: Descrever a prevalência de tuberculose multirresistente (TBMR) em pacientes com tuberculose em uma importante cidade brasileira através do II Inquérito Nacional de Resistência aos Fármacos Antituberculose, assim como as características sociais, demográficas e clínicas desses pacientes. MÉTODOS: De 2006 a 2007, amostras clínicas de pacientes de três hospitais e das cinco unidades básicas de saúde participantes do inquérito realizado em Porto Alegre foram coletadas e submetidas ao teste de sensibilidade aos fármacos. A confirmação das espécies de micobactérias ocorreu por métodos bioquímicos. RESULTADOS: Foram incluídos 299 pacientes. Desses, 221 (73,9%) eram homens e 77 (27,3%) tinham história de tuberculose. A idade média foi de 36 anos. Dos 252 pacientes testados para HIV, 66 (26,2%) estavam infectados. A prevalência da TBMR na amostra geral foi de 4,7% (IC95%: 2,3-7,1); enquanto essa foi de 2,2% (IC95%: 0,3-4,2) nos pacientes virgens de tratamento e de 12,0% (IC 95%: 4,5-19,5) naqueles com história de tratamento antituberculose. A análise multivariada mostrou que história de tuberculose e maior tempo para o diagnóstico associaram-se a TBMR. CONCLUSÕES: Caso esses resultados sejam confirmados em outros estudos no Brasil, a história de tratamento antituberculose e o maior tempo para o diagnóstico poderão ser utilizados como preditores de TBMR. .

A population-based study of first and second-line drug-resistant tuberculosis in a high-burden area of the Mexico/United States border

The resistance of 139 Mycobacterium tuberculosis (MTB) isolates from the city of Monterrey, Northeast Mexico, to first and second-line anti-TB drugs was analysed. A total of 73 isolates were susceptible and 66 were resistant to anti-TB drugs. Monoresistance to streptomycin, isoniazid (INH) and ethambutol was observed in 29 cases. Resistance to INH was found in 52 cases and in 29 cases INH resistance was combined with resistance to two or three drugs. A total of 24 isolates were multidrug-resistant (MDR) resistant to at least INH and rifampicin and 11 MDR cases were resistant to five drugs. The proportion of MDR-TB among new TB cases in our target population was 0.72% (1/139 cases). The proportion of MDR-TB among previously treated cases was 25.18% (35/139 cases). The 13 polyresistant and 24 MDR isolates were assayed against the following seven second-line drugs: amikacin (AMK), kanamycin (KAN), capreomycin (CAP), clofazimine (CLF), ethionamide (ETH), ofloxacin (OFL) and cycloserine (CLS). Resistance to CLF, OFL or CLS was not observed. Resistance was detected to ETH (10.80%) and to AMK (2.70%), KAN (2.70%) and CAP (2.70%). One isolate of MDR with primary resistance was also resistant to three second-line drugs. Monterrey has a high prevalence of MDR-TB among previously treated cases and extensively drug-resistant-MTB strains may soon appear.

Prevalência de Mycobacterium tuberculosis resistente em pacientes sob tratamento parcialmente intermitente ou sob tratamento diário / Prevalence of drug-resistant Mycobacterium tuberculosis in patients under intermittent or daily treatment

OBJETIVO: Comparar as taxas de prevalência de Mycobacterium tuberculosis resistentes entre pacientes sob tratamento parcialmente intermitente e daqueles sob tratamento diário. MÉTODOS: Foram utilizados dados da Organização Mundial de Saúde de 5.138 pacientes com TB pulmonar bacilífera no Brasil, que foram separados em dois grupos: um grupo de pacientes do Distrito Federal submetidos a um regime intermitente de três tomadas semanais após o primeiro mês de regime diário, e um grupo de pacientes dos estados brasileiras, submetidos somente a um regime diário. O padrão de resistência foi categorizado em resistência primária ou adquirida, conforme a existência de tratamento anterior. Além disso, multirresistência foi definida como a resistência simultânea à isoniazida e à rifampicina, enquanto monorresistência como a resistência a uma única droga. RESULTADOS: A prevalência da resistência primária como um todo no Distrito Federal e no restante do Brasil foi de 9,2 por cento e 9,3 por cento (p = 0,94), respectivamente. A prevalência de monorresistência foi de 6,6 por cento e 6,9 por cento (p = 0,89), respectivamente, e a de multirresistência, 1,0 por cento e 1,2 por cento (p = 0,85), respectivamente. A prevalência de resistência adquirida como um todo no Distrito Federal e no restante do Brasil foi de 15,8 por cento e 26,8 por cento (p = 0,39), respectivamente. A prevalência de monorresistência adquirida foi de 5,3 por cento e 13,7 por cento (p = 0,33), respectivamente, e a de multirresistência, 0,0 por cento e 10,2 por cento (p = 0,16), respectivamente. CONCLUSÕES: Não houve diferença significativa entre os índices de resistência observados na comunidade usuária do esquema parcialmente intermitente e do diário.

OBJECTIVE: To compare the prevalence rates of drug-resistant Mycobacterium tuberculosis in patients under intermittent treatment with those observed in patients under daily treatment. METHODS: We used World Health Organization data regarding 5,138 patients with active pulmonary TB in Brazil, separated into two groups: patients in the Federal District of Brasília, treated with a one-month daily regimen followed by an intermittent thrice-weekly regimen; and patients in other parts of Brazil, treated with a daily regimen only. The resistance pattern was categorized as primary or acquired, based on the history of previous treatment. Multidrug resistance was defined as resistance to at least isoniazid and rifampin, whereas monoresistance was defined as resistance to only one drug. RESULTS: The prevalence of primary resistance in the Federal District of Brasília and in the other parts of Brazil, respectively, was as follows: overall, 9.2 percent and 9.3 percent (p = 0.94); monoresistance, 6.6 percent and 6.9 percent (p = 0.89); and multidrug resistance, 1.0 percent and 1.2 percent (p = 0.85). The prevalence of acquired resistance in the Federal District of Brasília and in the other parts of Brazil, respectively, was as follows: overall, 15.8 percent and 26.8 percent (p = 0.39); monoresistance, 5.3 percent and 13.7 percent (p = 0.33); and multidrug resistance, 0.0 percent and 10.2 percent (p = 0.16). CONCLUSIONS: No significant differences were found between patients treated with an intermittent regimen and those treated with a daily regimen in term of resistance rates.