A major challenge in cancer treatment is acquired or intrinsic multidrug resistance (MDR) to chemotherapeutics. A notorious mediator of MDR is P-glycoprotein (P-gp, ABCB1), product of the human MDR1 gene, which actively effluxes cytotoxic drugs from cancer cells, resulting in sub-therapeutic intracellular concentrations. Understanding how P-gp interacts with drugs has been severely limited by the lack of high-resolution structures of P-gp. Although numerous efforts to obtain an X-ray crystal structure of P-gp have been attempted, human P-gp has never been crystallized. However, mouse P-gp (87% homologous to human P-gp) has been crystallized, and several structures of mouse P-gp have been recently reported. Despite a high degree of homology, it is currently unknown why mouse P-gp can be crystallized while human P-gp cannot. The studies presented in this thesis describe the creation of novel chimeras of mouse and human P-gp as an approach to investigate whether specific protein domains are responsible for differences in the ability to form crystals between mouse and human P-gp. A range of chimeras, created by protein domain swapping, were expressed in mammalian cells and all were found to retain MDR transport function demonstrating that P-gp can tolerate major structural changes. High-level expression of all chimeras was achieved by baculovirus-mediated heterologous protein expression. Chimeric proteins were purified by a multi-step process including immobilized metal affinity chromatography and size exclusion chromatography. Crystallization screening obtained protein crystals for two of the chimeras, indicating the approach adopted is a successful strategy, and an advance along the path towards a high-resolution structure of human P-gp.

Background Trastuzumab resistance imposes a major limitation to the successful treatment of HER2 positive breast cancer. The expression of HER4 and its prognostic value is controversial in breast cancer. Furthermore, its role in trastuzumab treatment and resistance in HER2 positive breast cancer has not been reported. Methods The effects of trastuzumab on HER4 cleavage and its localisation were studied in both parental and trastuzumab-resistant SKBR3 and BT474 cells using western blot, RT-PCR, nuclear fractionation and confocal microscopy. Tissue microarrays consisting of a cohort of HER2 positive breast cancer patients were stained for HER4 by immunohistochemistry and the results were correlated with patients’ outcome. This study also assessed HER4 expression in the tumor samples from a window study of trastuzumab alone or in combination with neoadjuvant chemotherapy in HER2 positive breast cancer patients. Results Trastuzumab treatment upregulated HER4 mRNA, and increased expression of both 80 and 180 kDa HER4 protein isoforms, and induced nuclear translocation of 80kDa HER4 protein isoforms, which the results similar to heregulin stimulation. This was also seen in trastuzumab resistant cells although HER4_80kDa and nuclear HER4 decreased upon overnight withdrawal of trastuzumab in resistant cell lines. In addition, knockdown of HER4 protein expression by specific siRNAs increased trastuzumab sensitivity and reversed trastuzumab resistance in SKBR3 and BT474 cells, confirming the importance of HER4 in trastuzumab response. This study also showed that trastuzumab-induced HER4 nuclear translocation is due to HER4 activation and cleavage since γ-secretase inhibitor (GSi) and neratinib prevented the process when combined with trastuzumab treatment, correlating with an increased apoptosis and decreased cell viability. There was also increased nuclear HER4 expression in tumors from both BT474 xenografts and from patients with breast cancer treated with trastuzumab monotherapy. Furthermore, nuclear HER4 predicted poor clinical response to trastuzumab monotherapy in patients undergoing a window study and was a poor prognostic factor in HER2 positive breast cancer. Conclusions This study suggests HER4 activation, cleavage and nuclear translocation play a key role in trastuzumab resistance in HER2 positive breast cancer. Nuclear HER4 could be a novel predictive and prognostic biomarker in HER2 positive breast cancer patients.

The purpose of the study was to investigate the problem of defaulting of tuberculosis (TB) treatment in the Khomas region of Namibia. A quantitative, descriptive research approach was used to investigate the reasons for defaulting of TB treatment under the DOTS strategy in Khomas Region of Namibia. Data was collected by using a structured interview schedule with 54 participants who were on DOTS strategy and defaulted. Data were analysed by using the Epi info computer program. The major findings from the data obtained, revealed that the respondents did not have an in-depth knowledge of TB and the health education was not successful. This contributed to the defaulting of their treatment. Based on the study findings nurses should improve health education to TB patients on DOTS and also educate members of the community to address the stigmatisation of TB. Recommendations for further improvement in the compliance of TB treatment were made. / Public Health / M.A. (Public Health)

Desde a primeira enzima ?-lactamase de espectro estendido (ESBL) detectada, na década de 1980, o número de diferentes enzimas ESBL têm aumentado exponencialmente. Houve também aumento no número de relatos de isolamento de bactérias resistentes presentes em alimentos de origem animal. O objetivo deste estudo foi avaliar enterobactérias de microbiota de frangos comerciais saudáveis, de granjas localizadas no interior do Estado de São Paulo (Brasil), quanto à resistência a antimicrobianos e ao potencial de virulência. Foram avaliadas todas as enterobactérias que apresentaram resistência à cefotaxima e/ou ceftazidima de 200 frangos comerciais para consumo humano. O teste de sensibilidade aos antimicrobianos foi realizado por disco de difusão para diferentes classes de antimicrobianos incluindo ?- lactâmicos e não ?-lactâmicos. Reação em cadeia da polimerase e sequenciamento foram utilizados para a pesquisa de genes codificadores de ESBL, ?-lactamases AmpC e determinantes de resistência às quinolonas mediada por plasmídeos (PMQR). A similaridade genética dos isolados foi caracterizada por eletroforese em campo pulsado (PFGE) e a localização cromossômica ou plasmideal de genes de resistência foi avaliada por I-Ceu IPFGE ou S1-PFGE. Além disso, experimentos de conjugação, tipagem de plasmídeos, investigação de filogenia e de virulência foram realizados. Em todas as amostras de cloaca coletadas foram identificados Enterobacteriaceae, incluindo Escherichia coli, Escherichia fergusonii, Klebsiella oxytoca e Klebsiella pneumoniae resistentes à cefotaxima e/ou ceftazidima. Salmonella sp não foi detectada. Foi encontrada ampla diversidade genômica entre todos os isolados classificados entre diferentes tipos de PFGE. Foram detectados diferentes genes codificadores de ?-lactamases, a maioria em diferentes plasmídeos, de diversos tamanhos, sendo alguns conjugativos, presentes em diferentes populações bacterianas. Foram identificados isolados de E. coli produtores de CTX-M-2, com inserção do gene blaCTX-M-2 no cromossomo bacteriano. Plasmídeo IncI (ST113/ST114) foi identificado carreando o gene blaCTX-M-8. Foram também encontrados os genes codificadores de ?- ii lactamase, blaCTX-M-2 e blaCTX-M-15, sendo carreados por plasmídeos. Foi identificado gene blaCMY-2 disseminado por plasmídeos de diferentes grupos de incompatibilidade, na população comensal de E. coli. Nos isolados que abrigavam gene PMQR, além das resistências às quinolonas, foi observado também resistência a outras importantes classes de antimicrobianos. Genes determinantes de PMQR abrigados em plasmídeos tipo ColE foram encontrados em E. coli, E. fergusonii, K. oxytoca e K. pneumoniae. Todas as aves comerciais de granjas localizadas no interior do Estado de São Paulo, incluídas nesse estudo, apresentaram isolados considerados multirresistentes a antimicrobianos e o trato intestinal destes frangos é reservatório dos genes de resistência em enterobactérias da microbiota normal. Além disso, alguns isolados demonstraram alto potencial de virulência, incluindo a capacidade de adesão e invasão em células epiteliais in vitro. / of commercial poultry in farms located at the countryside of São Paulo State (Brazil). All enterobacteria presenting cefotaxime and/or ceftazidime resistance from 200 commercial broiler chickens for human consumption were evaluated. Antimicrobial susceptibility testing was performed by disc diffusion for different classes of antimicrobials, including ?-lactams and non-?-lactams. The genes encoding ESBL, ampC ?-lactamases and determinants of plasmid mediated quinolone resistance (PMQR) were screened by polymerase chain reaction and sequencing. Genetic similarity of bacterial isolates was characterized by pulsed field gel electrophoresis (PFGE) and the location of the resistance genes in the chromosome or plasmids was evaluated by I-CeuI-PFGE or S1-PFGE. Additionally, experiments of conjugation, plasmid typing, phylogeny and virulence characterization were performed. Enterobacteriaceae were identified in all cloacal swab samples, including Escherichia coli, Escherichia fergusonii, Klebsiella oxytoca and Klebsiella pneumoniae resistant to cefotaxime and/or ceftazidime. Salmonella sp. was not detected. High genetic diversity was detected among all isolates, classified into diferent types of PFGE. Different genes coding for ?-lactamases were detected, harbored in diverse plasmids, of different sizes, some were conjugative and were present in different bacterial populations. E. coli isolates producing CTX-M-2 were identified, harbouring the blaCTX-M-2 gene inserted into the chromosome. IncI (ST113/ST114) plasmid was identified carrying the blaCTX-M-8 gene. The ?-lactamase coding genes, blaCTX-M-2 and blaCTX-M-15 were also found in plamids. The gene blaCMY-2 was found disseminated in different types of plasmid replicons in the commensal E. coli population. In isolates harbouring PMQR genes, in addition to the quinolones resistance, was observed resistance to other important antimicrobials classes was observed. PMQR determinant genes harbored in ColE-like plasmids were found in E. coli, E. fergusonii, K. oxytoca and K. pneumoniae. All commercial poultry from farms located at São Paulo State, evaluated in this study, carried isolates considered multidrug resistant and the intestinal tract of these chickens is reservoir of resistant genes blaCTX-M-2, blaCTX-M-8 and blaCTX-M-15 in enterobacteria from the normal microbiota. Moreover, some have demonstrated a high virulence potential, with adhesion and invasion capacity in epithelial cells cultured in vitro.

Orientador: Márcio Garcia Ribeiro / Resumo: Escherichia coli é o principal agente de mastite clínica bovina de origem ambiental, caracterizado pela complexidade de fatores de virulência (FV). O patógeno causa sinais clínicos que variam desde alterações exclusivamente no leite (grau 1 ou leve), no quarto afetado (grau 2 ou moderado), até manifestações sistêmicas (grau 3 ou grave). No entanto, até o momento, não está estabelecido o perfil de genes deste patógeno relacionados à virulência em infecções mamárias em vacas, tampouco com a gravidade clínica dos casos. Neste cenário, o presente estudo investigou 18 genes associados com E. coli extraentérica (ExPEC), o perfil “in vitro” de motilidade swimming e swarming, e a sensibilidade/resistência aos antimicrobianos em 114 isolados de E. coli obtidos de vacas com mastite clínica com escores de gravidade 1 (45/114=39,5%), 2 (62/114=54,4%) e 3 (7/114=6,1%). Os principais genes codificadores de FV detectados foram de adesinas (fimH, 114/114=100%; ecpA, 73/114=64,0%; fimA, 36/114=31,6%), resistência ao soro (traT, 93/114=81,6%; ompT, 40/114=35,1%), sideróforos (irp2, 11/114=9,6%) e hemolisina (hlyA, 8/114=7%). Os isolados apresentaram 99,1% (113/114) de resistência in vitro a bacitracina e cloxacilina, 98,2% (112/114) a lincosamina e 54,4% (62/114) a eritromicina. Do total de isolados, 98,2% (n=112/114) foram multirresistentes pelo cálculo do índice de resistência múltipla aos antimicrobianos (IRMA). Não houve diferença estatística significante entre as medianas para motilidade ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Escherichia coli is the major pathogen involved in the etiology of bovine mastitis from the environment origin. This pathogen is characterized by a complexity of virulence factors (VF). Mammary infections by E. coli has shown a wide range of clinical signs causing changes in milk (score 1 or mild), quarters (score 2 or moderate), and systemic signs (score 3 or severe). Nevertheless, to date, the profile of the genes related to the virulence of this pathogen in mammary infections and the severity scores of the cases are not fully understood. In this scenario, a panel of 18 genes associated with extra-intestinal E. coli (ExPEC) were investigated, in addition to in vitro swimming and swarming motility profile, and antimicrobial susceptibility/resistance pattern among 114 E. coli strains isolated from cows with clinical mastitis showing severity scores 1 (45/114=39.5%), 2 (62/114=54.4%) and 3 (n=7/114=6.1%). The main genes related to VF harbored by isolates were adhesins (fimH, 114/114=100%; ecpA, 73/114=64.0%; fimA, 36/114=31.6%), serum resistance (traT, 93/114=81.6%; ompT, 40/114=35.1%), siderophores (irp2, 11/114=9.6%) and hemolysin (hlyA, 8/114=7%). Among studied isolates, 99.1% (113/114) showed in vitro resistance to bacitracin and cloxacillin, 98.2% (112/114) to lincosamin, and 54.4% (62/114) to erytromycin. Out of the total isolates, 98.2% (112/114) were considered multidrug resistant based on multiple antimicrobial resistance (MAR) index. No statistical difference was obs... (Complete abstract click electronic access below) / Doutor

La diffusion des bactéries multirésistantes aux antibiotiques associée à une diminution du nombre de nouveaux antibiotiques représente un véritable enjeu de santé publique. De nos jours, un vieil antibiotique, la colistine, connait un récent regain d’intérêt, constituant parfois la seule alternative thérapeutique. La colistine est, alors, qualifiée d’antibiotique de « dernier recours ». Cependant, il a été constaté l’apparition de souches résistantes à la colistine. L’objectif principal de ce travail de thèse a été d’étudier le(s) mécanisme(s) de résistance à la colistine chez K. pneumoniae. Afin de mener à bien notre projet, nous nous sommes intéressés à deux aspects de la problématique. Dans un premier temps, nous avons cherché à mieux comprendre ce mécanisme, en associant une étude génotypique à une étude phénotypique. Et dans un second temps, nous avons cherché des alternatives thérapeutiques, en évaluant différentes associations antibiotiques / The global spread of multidrug-resistant Gram-negative bacteria associated with a decrease in the number of new antibiotic therapies is a major public health issue. Colistin is often referred to as the "last-resort" antibiotic, used as the only therapeutic alternative for MDR Gram-negative bacteria infection, which explains the current renewal of interest in this antimicrobial agent. However, the appearance of colistin-resistant bacterial strains has been already observed. The main objective of this PhD work was to study the colistin resistance mechanism (s) in K. pneumoniae by looking at two aspects of the problem. Firstly, we sought to better understand this mechanism, associating a genotypic study with a phenotypic study. Next, we looked for therapeutic alternatives, by evaluating different antibiotic combinations

Enterococos são ubíquos no ambiente e fazem parte da microbiota do trato gastrintestinal de humanos e animais. A importância dessas bactérias tem sido associada com infecções hospitalares e resistência a múltiplas drogas, principalmente à vancomicina. O objetivo do presente estudo foi realizar a caracterização molecular de cepas de Enterococcus spp. resistentes à vancomicina (VRE) isoladas a partir de amostras coletadas de pacientes hospitalizados, água superficial de rios urbanos e carne de frango comercializada no Brasil. A presença do gene vanA foi confirmada em 20 cepas multirresitentes isoladas durante 1997-2011. Dentre os isolados VRE, 12 cepas foram identificadas como E. faecium e oito como E. faecalis. Cepas de E. faecium isoladas de amostras clínicas e águas foram classificadas como clonalmente relacionadas pelo PFGE, com perfil virulência predominante (acm+, esp+). Adicionalmente, enquanto cepas de E. faecium isoladas dos rios pertenceram aos ST203, ST412 e ST478 (previamente caracterizados como endêmicos em hospitais brasileiros), novos STs foram identificados entre as cepas de E. faecalis (ST614, ST615 e ST616) e E. faecium (ST953 e ST954) isoladas de alimentos. Sequências completas do transposon Tn1546 das cepas clínicas VREfm 320/07 (ST478) e ambiental VREfm 11 (ST412) mostraram Tn1546-like element de ~12800 pb, com um ponto de mutação no gene vanA na posição 7.698 (substituição do nucleotídeo T pelo C) e uma no gene vanX na posição 8.234 (G pelo T). Além disso, uma deleção na extremidade esquerda do Tn1546, e as sequências IS1251 e IS1216E na região intergênica vanHS e vanYX, respectivamente, também foram detectados. A este respeito, a IS1216E na região intergênica vanXY constitui um conjunto de genes previamente relatado em cepas clínicas de VREfm no Brasil, denotando uma característica regional. IS1216E tem sido associada com os genes tcrB e aadE que conferem resistência ao cobre e aminoglicosídeos, em E. faecium e Streptococcus agalactiae, respectivamente. Portanto, essa IS pode contribuir para a rápida aquisição de resistência antimicrobiana entre as espécies de cocos Gram-positivos clinicamente importantes. Os tipos de Tn1546 indistiguíveis que foram identificados no atual estudo isolados de humano e ambientes aquáticos sugerem uma comum partilha de um pool de genes de resistência à vancomicina. / Enterococci are ubiquitous in the environment and in the intestinal tract of humans and animals. The importance of these bacteria has been associated with nosocomial infection and multiple resistance to antimicrobial agents, mainly vancomycin. The aim of the present study was to perform molecular characterization of vancomycin-resistant Enterococcus spp. strains (VRE) isolated from hospitalized patients, surface water of urban rivers and retail chicken meat in Brazil. The presence of the vanA gene was confirmed in 20 multidrug-resistant strains isolated in 1997-2011. Among these VRE isolates, (n = 12) were identified as E. faecium and (n = 8) as E. faecalis. E. faecium strains isolated from water and clinical samples were classified as clonally related by PFGE, the predominant virulence profile being (acm+, esp+). Additionally, while E. faecium strains isolated from rivers belonging to ST203, ST412 and ST478 (previously characterized as endemic in Brazilian hospitals), new STs were identified among strains of E. faecalis (ST614, ST615 and ST616) and E. faecium (ST953 and ST954) isolated from food. Complete sequences of transposon Tn1546 from VREfm clinical strain 320/07 (ST478) and environmental strain VREfm 11 (ST412) showed a Tn1546-like element of ~12800 bp, with T7698C vanA and G8234T vanX mutations. Moreover, deletion of the Tn1546 left extremity, and the IS1251 and IS1216E sequence inside the vanHS and vanYX intergenic region, respectively, were also detected. In this regard, the IS1216E sequence inside the vanXY intergenic region constitutes a gene array previously reported for Brazilian VREfm clinical strains alone, denoting a regional characteristic. IS1216E has been associated with tcrB and aadE genes, which confer resistance to copper and aminoglycosides, in E. faecium and Streptococcus agalactiae, respectively. Therefore, IS1216E should contribute to rapid acquisition of antimicrobial resistance among species of the clinically important Gram-positive cocci. On the other hand, Tn1546-like elements were identical among clinical and environmental VREfm isolates, suggesting sharing of a common vancomycin resistance gene pool.

Mammalian ABC (ATP-binding cassette) transporters are integral membrane proteins that translocate allocrites across biological membranes using ATP as a substrate. ABCB1 is a polyspecific efflux pump which can confer multidrug resistance in cancer. ABCB1 is also expressed in a variety of normal tissues where it functions to prevent the accumulation of toxic allocrites. Direct inhibition of ABCB1 can therefore have detrimental effects on patients. Identification of ABCB1-interacting partners that influence trafficking or function would therefore provide alternative targets for therapy which may be cell- or tissue-type specific. The “split-ubiquitin” yeast two-hybrid system, that can detect protein:protein interactions at the plasma membrane, was used to screen for ABCB1-interactors in a human liver library. All candidates isolated from the screen interacted with ABCB1 in a non-specific manner when subjected to strict testing. ABCB4, a close relative of ABCB1, is expressed primarily at the hepatocyte canalicular membrane where it flops phosphatidylcholine (PC) into the outer leaflet for extraction by bile salts. Many ABCB4 non-synonymous mutations have been linked to cholestatic liver diseases in humans, but data confirming an impact on ABCB4 function is lacking. Transient expression of wild-type (WT) ABCB4 in tissue culture has proved difficult because the protein is toxic to HEK293T cells. However, co-expression of the phosphatidylserine flippase ATP8B1 (FIC1) and its accessory protein CDC50A allowed the cells to tolerate ABCB4. To investigate the impact of SNPs on ABCB4 function, equivalent changes were introduced into the ABCB4 cDNA for transient expression in the presence or absence of ATP8B1/CDC50A. ABCB4 expression and targeting to the plasma membrane were monitored by western analysis and confocal microscopy, respectively, and, by “feeding” the transfected cells [methyl-3H]choline, PC efflux to added bile salt acceptor was measured. By thus mimicking the situation at the canalicular membrane I report the preliminary characterisation of nine variants of ABCB4 that have been linked to cholestatic liver disease.

A hanseníase é uma das doenças mais antigas da humanidade, chamada anteriormente no Brasil de lepra e encontrada em registros de antes de Cristo. É uma doença infecciosa, de evolução crônica, que acomete predominantemente a pele, os nervos periféricos e as mucosas, além de outros órgãos e estruturas, sendo o agente etiológico, o Mycobacterium leprae. A Organização Mundial de Saúde propõe o uso dos esquemas terapêuticos padronizados ou substitutivos para controle desta doença. É pressuposto que um dos motivos de abandono do tratamento seja a ocorrência de reações adversas relativas à terapia. A estratégia global de controle da hanseníase, portanto, deve incluir o desenvolvimento de uma vigilância efetiva dentro dos serviços de saúde. Com o objetivo de analisar o perfil de segurança da farmacoterapia utilizada no tratamento da hanseníase, foi realizado um estudo observacional, transversal, retrospectivo com a população de pacientes em tratamento para hanseníase, com esquemas padrão ou substitutivo, em Hospital Universitário de Salvador/BA, 2009 a 2015. Dos 292 pacientes eleitos, 68,8% dos indivíduos eram procedentes da capital; 70,5% pertenciam à faixa etária de adultos; 52,7% eram do gênero feminino; 47,6% eram de cor parda; 40,1% dos indivíduos eram casados; 15,4% tinham apenas ensino fundamental incompleto; 64,4% apresentaram resultado de baciloscopia negativo; 60,3% classificados como paucibacilares; 30,5% dos pacientes com forma clínica predominante tuberculóide e 59,9% das pessoas não desenvolveram surto reacional durante a poliquimioterapia. Foram notificados 114 indivíduos com suspeita de pelo menos uma reação adversa a medicamento (RAM), resultando em 150 notificações. A suspeita de reação mais frequente foi anemia (57%), seguida de xerose cutânea (6%), hiperpigmentação (3%) e cefaleia (4%), dentre outras. Em 75,4% dos casos notificados, a dapsona foi o medicamento suspeito no desencadeamento da reação adversa. A razão de prevalência foi calculada para as notificações de suspeita realizadas e 52% dos pacientes com resultado normal para deficiência da enzima glicose 6-fosfato desidrogenase foram notificados com suspeita de anemia, além de 31,6% de substituições de esquema dentre os notificados com suspeita de reação adversa. A poliquimioterapia padrão, nesta população especificamente, demonstrou ser segura, uma vez que apesar do número elevado de notificações de suspeitas de RAM, a maioria apresentou resolução no curso da terapia, com um percentual reduzido de substituições. A pesquisa agregou valores frente à escassez de achados na literatura para tal população. Os resultados poderão contribuir para um maior cuidado com os pacientes assistidos, ratificando a necessidade de vigilância contínua do uso da poliquimioterapia. / Hansen's Disease is one of the oldest diseases of mankind, formerly known as leprosy, and found in records from before Christ. It is an infectious disease, of chronic evolution, which predominantly affects the skin, peripheral nerves and mucous membranes, as well as other organs and structures. Its etiologic agent is Mycobacterium leprae. The World Health Organization suggest the use of the standard therapeutic regimen or replacement regimen in order to treat the disease. It is assumed that one reason for treatment withdrawal is the occurrence of adverse reactions during the therapy. In order to analyze the safety profile of the pharmacotherapy chosen in the treatment, an observational, cross-sectional, retrospective study was carried out with the population of patients undergoing treatment for Hansen's Disease with standard or replacement regimens at the University Hospital in Salvador - BA, 2009 to 2015. 292 patients were elected: 68.8% of them were from the capital; 70.5% belonged to the adult age group; 52.7% were female; 47.6% were brown; 40.1% of the individuals were married; 15.4% had not finished middle school; 64.4% presented negative sputum culture results; 60.3% classified as paucibacillary cases; 30.5% of the patients were diagnosed with predominant tuberculoid clinical form and 59.9% of the patients did not develop a reaction outbreak during multidrug therapy. Reports showed that 114 subjects were suspected of having at least one drug adverse reaction, resulting in 150 reports. The most frequent suspected reaction was anemia (57%), followed by xerodermia (6%), hyperpigmentation (3%) and headache (4%), among others. In 75.4% of reported cases, Dapsone was the suspected drug. The prevalence ratio was calculated for the suspected reports. 52% of patients with normal results for glucose-6-phosphate dehydrogenase enzyme deficiency were suspected of having anemia, in addition to 31.6% of regimen replacements among those reported with suspected adverse reactions. The standard multidrug therapy, particularly among this population, has been proven to be a safe choice, despite the high numbers of suspected reports of ADR, most patients presented signs of resolution during of therapy, with a low percentage of replacements. The research added values regarding the safety profile of the treatment for Hansen's Disease in the face of the scarcity of findings in the literature for such population. The results not only will contribute to a greater care with the elected patients, but will also confirm the need for continuous watching of multidrug therapy use.

IntroduÃÃo: A aderÃncia ao tratamento de doenÃas crÃnicas à uma questÃo complexa e envolve nÃo sà a responsabilidade das pessoas afetadas, mas tambÃm das equipes profissionais de saÃde e das redes sociais. Nos Ãltimos anos, a nÃo adesÃo à poliquimioterapia (PQT) foi reduzida significativamente no Brasil. No entanto, a questÃo ainda à um obstÃculo importante no controle da doenÃa, podendo levar a permanÃncia de fontes de infecÃÃo, cura incompleta, complicaÃÃes irreversÃveis e multiresistÃncia. MÃtodos: Realizamos um estudo de base populacional em 78 municÃpios pertencentes a uma Ãrea endÃmica (cluster 1) de hansenÃase, no norte do estado de Tocantins. Tocantins à o estado com os maiores Ãndices de taxa de detecÃÃo anual (88.54/100.000 na populaÃÃo geral e 26.48/100.000 em <15 anos em 2009). Aplicou-se questionÃrio estruturado com perguntas relativo a caracterÃsticas sÃciodemogrÃficas, clÃnicas, relacionadas ao serviÃo e comportamento. Para a anÃlise de fatores de risco definiu-se faltoso como indivÃduos que nÃo completaram as doses supervisionadas em 7 meses (PB) e em 13 meses (MB), e abandono o paciente que nÃo compareceu nos Ãltimos 12 meses à unidade de saÃde onde faz o tratamento. Resultados: Do total de 936 indivÃduos incluÃdos na anÃlise, 491 (52,5%) eram do sexo masculino. A idade variou de 5 a 99 anos (mÃdia = 42,1 anos). Duzentos e vintecinco (24,0%) eram analfabetos. No total, 497 (55,6%) foram classificados como PB, e 395 (44,1%) como MB. Foram identificados 28 (3,0%) pacientes que abandonaram PQT; 16 abandonos foram detectados pela revisÃo do sistema de informaÃÃo SINAN, e um adicional de 12 abandonos no local nos prontuÃrios dos pacientes durante o trabalho de campo. No total, 147/806 (18,2%) foram identificados como faltosos. O abandono foi significativamente associado com: baixo nÃmero de cÃmodos por domicÃlio (OR = 3,43; intervalo de confianÃa de 95%: 0,98-9,69, p = 0,03); mudanÃa de residÃncia apÃs o diagnÃstico (OR = 2,90; 0,95-5,28; p = 0,04) e baixa renda familiar (OR = 2,42; 1,02-5,63; p = 0,04). Falta Ãs doses supervisionadas mostrou associaÃÃo com: baixo nÃmero de cÃmodos por domicÃlio (OR = 1,95; 0,98-3,70; p = 0,04); dificuldade em engolir remÃdios da PQT (OR = 1,66; 1,03-2,63; p = 0,02); falta temporÃria de PQT nos centros de saÃde (OR = 1,67; 1,11-2,46; p = 0,01) e mudanÃa de residÃncia apÃs o diagnÃstico (OR = 1,58; 1,03-2,40; p = 0,03). A regressÃo logÃstica identificou que a falta temporÃria de PQT foi um fator de risco independente para os faltosos (OR ajustada = 1,56; 1,05-2,33; p = 0,03), e o tamanho da residÃncia foi fator de proteÃÃo (OR ajustada = 0,89 por cada quarto adicional; 0,80-0,99, p = 0,03). O tamanho da residÃncia tambÃm foi independentemente associada à falta no tratamento (OR ajustada = 0,67; 0,52-0,88; p = 0,003). AlÃm disso, foram identificados 334 (35,6%) participantes que disseram que tinham interrompido a PQT pelo menos uma vez. O tempo mÃdio de interrupÃÃo indicado pelos participantes foi de 15 dias, com um mÃximo de trÃs anos (variaÃÃo interquartil: 6-30 dias). A razÃo mais comum para a interrupÃÃo dada pelos pacientes foi a nÃo disponibilidade de medicamentos no respectivo centro de saÃde (211; 62,9%), seguido por esquecimento (44; 12,0%) e efeitos adversos à PQT (28; 8,3%). ConclusÃes: O estudo mostra que ainda existem desafios a serem enfrentados em relaÃÃo à adesÃo à PQT no Brasil. Como conseqÃÃncia dos esforÃos realizados pelo programa de controle de hansenÃase do Estado do Tocantins, fatores relacionados ao serviÃos desempenharam um papel menor, apesar de escassez intermitente de fornecimento de medicamentos. Uma abordagem integrada à necessÃria para melhorar ainda mais o controle, focando nos grupos populacionais mais vulnerÃveis, como as populaÃÃes carentes e migrantes. Produtores da PQT devem considerar outras formulaÃÃes orais mais facilmente aceitas pelos pacientes. Considerando as conseqÃÃncias da baixa adesÃo ao tratamento, tais como o possÃvel desenvolvimento de resistÃncia do Mycobacterium leprae contra os antibiÃticos da PQT, e persistÃncia de fontes de transmissÃo em comunidades, futuros estudos devem ser aprofundados para melhorar a aderÃncia à PQT, principalmente em regiÃes hiperendÃmicas / Background: Adherence to treatment of chronic diseases is a complex issue and involves not only responsibility of the diseased persons, but also the health professional teams and the patientsâ social networks. In the last years, non-adherence to multidrug therapy (MDT) against leprosy has been reduced significantly in Brazil. However, low adherence to MDT is still an important obstacle of disease control, and may lead to remaining sources of infection, incomplete cure, irreversible complications, and multidrug resistance. Methods: We performed a population-based study in 78 municipalities pertaining to a leprosy hyperendemic cluster in northern Tocantins State, central Brazil. Tocantins is the State with highest leprosy detection rates (annual detection rate of 88.54/100.000 in the general population, and of 26.48/100.000 in <15 year-olds in 2009). We reviewed the database of the National Information System for Notifiable Diseases (Sistema de InformaÃÃo de Agravos de NotificaÃÃo â SINAN), and applied structured questionnaires on leprosy-affected individuals regarding socio-demographic, clinical, service-related and behavior-related characteristics. Two different outcomes for assessment of risk factors were used: defaulting (defined as individuals with incomplete MDT not presenting to the health care center for monthly supervised treatment for >12 months); and interruption of MDT (defined as duration PB treatment > 7 months; and of MB treatment > 13 months). In addition, we asked participants who said that they had interrupted MDT at least once in an open question about their reasons for interrupting. Results: Of the total of 936 individuals included in data analysis, 491 (52.5%) were males; the age ranged from 5 to 99 years (mean=42.1 years). Two-hundred and twenty-five (24.0%) were illiterate. In total, 497 (55.6%) were classified as PB, and 395 (44.1%) as MB leprosy. We identified 28 (3.0%) patients who defaulted MDT; 16 defaulters were included by reviewing the SINAN data information system, and an additional 12 locally in the patientsâ charts during field work. In total, 147/806 (18,2%) interrupted MDT. Defaulting was significantly associated with: low number of rooms per household (OR=3.43; 95% confidence interval: 0.98â9.69; p=0.03); moving to another residence after diagnosis (OR=2.90; 0.95â5.28; p=0.04); and low family income (OR=2.42; 1.02â 5.63: p=0.04). Interruption of treatment was associated with: low number of rooms per household (OR=1.95; 0.98â3.70; p=0.04); difficulty in swallowing MDT drugs (OR=1.66; 1.03â2.63; p=0.02); temporal non-availability of MDT at the health center (OR=1.67; 1.11â2.46; p=0.01); and moving to another residence (OR=1.58; 1.03â2.40; p=0.03). Logistic regression identified temporal nonavailability of MDT as an independent risk factor for treatment interruption (adjusted OR=1.56; 1.05â2.33; p=0.03), and residence size as a protective factor (adjusted OR=0.89 per additional number of rooms; 0.80â0.99; p=0.03). Residence size was also independently associated with defaulting (adjusted OR=0.67; 0.52â0.88; p=0.003). In addition, we identified 334 (35.6%) participants who said that they had interrupted MDT at least once. The median time of interruption stated by study participants was 15 days, with a maximum of three years (interquartile range: 6-30 days). The most common reason for interruption given by these was non-availability of medication at the respective health care centre (211; 62.9%). Others forgot to take the medicine (44; 12.0%) or interrupted due to drug-related adverse events (28; 8.3%). Conclusions: The study shows that there are still challenges to be tackled regarding MDT in Brazil. As a consequence of the efforts done by the Tocantins State Leprosy Control Program, healthservice related factors played a minor role, despite intermittent shortage of drug supply. An integrated approach is needed for further improving control, focusing on the most vulnerable population groups such as the socio-economically underprivileged and migrants. MDT producers should consider oral drug formulations that may be more easily accepted by patients. Considering the consequences of low adherence to treatment, such as possible development of MDT resistance, and persisting sources of transmission, future in-depth studies are needed to improve further adherence, mainly in hyperendemic regions