Antifungal stewardship: What we need to know.

Antimicrobial stewardship refers to a well-coordinated program which promotes the scientific and rational use of antimicrobials, reduces the chances of drug resistance and improves patient outcomes. A comprehensive English language literature search was done across multiple databases (PubMed, EMBASE, MEDLINE and Cochrane) for the period 1990-2022, revealing a large volume of reports of growing resistance to established antifungal therapies, against a backdrop of irrational and unscientific prescriptions. As a result of this, antifungal stewardship, a new kid on the block, has recently garnered attention. This review article is an attempt to summarise the basic concept of stewardship programs, highlighting the dire need to implement the same in the present situation of antifungal resistance and treatment failure.

Unraveling the mechanisms of intrinsic drug resistance in Mycobacterium tuberculosis.

Tuberculosis (TB) is among the most difficult infections to treat, requiring several months of multidrug therapy to produce a durable cure. The reasons necessitating long treatment times are complex and multifactorial. However, one major difficulty of treating TB is the resistance of the infecting bacterium, Mycobacterium tuberculosis (Mtb), to many distinct classes of antimicrobials. This review will focus on the major gaps in our understanding of intrinsic drug resistance in Mtb and how functional and chemical-genetics can help close those gaps. A better understanding of intrinsic drug resistance will help lay the foundation for strategies to disarm and circumvent these mechanisms to develop more potent antitubercular therapies.

Drug resistance in leprosy: An update following 70years of chemotherapy.

Leprosy is one of the oldest infectious diseases, reported for more than 2000years. Leprosy elimination goal as a public health problem set by the World Health Organization, aiming for a global prevalence rate<1 patient in a population of 10,000, was achieved in 2000 mainly thanks to the worldwide use of leprosy drugs starting in the 1980s and their access at no cost for patients since 1995. However, around 200,000 new cases are still reported each year, particularly in India, Brazil, and Indonesia. As with other bacteria of medical interest, antimicrobial resistance is observed in Mycobacterium leprae strains in several parts of the world, despite multidrug therapy being the recommended standard leprosy treatment to avoid resistance selection since 1982. Therefore, identifying and monitoring resistance is necessary. We provide an overview of the historical facts that led to the current drug resistance situation, the antibiotics effective against M. leprae, their mechanisms of action and resistance, and resistance detection methods. We also discuss therapeutic management of the resistant cases, new genes with potential roles in drug resistance and bacterial adaptation, new drugs under investigation, and the risk for resistance selection with the chemoprophylaxis measures.

The Role of Plasma Membrane Pleiotropic Drug Resistance Transporters in the Killer Activity of Debaryomyces hansenii and Wickerhamomyces anomalus Toxins.

The killer strains of Debaryomyces hansenii and Wickerhamomyces anomalus species secrete antimicrobial proteins called killer toxins which are active against selected fungal phytopathogens. In our research, we attempted to investigate the role of plasma membrane pleiotropic drug resistance (PDR) transporters (Pdr5p and Snq2p) in the mechanism of defense against killer toxins. Saccharomyces cerevisiae mutant strains with strengthened or weakened pleiotropic drug resistance due to increased or reduced number of mentioned PDR efflux pumps were tested for killer toxin susceptibility. The present study demonstrates the influence of the Snq2p efflux pump in immunity to W.anomalus BS91 killer toxin. It was also shown that the activity of killer toxins of D. hansenii AII4b, KI2a, MI1a and CBS767 strains is regulated by other transporters than those influencing W. anomalus killer toxin activity. In turn, this might be related to the functioning of the Pdr5p transporter and a complex cross-talk between several regulatory multidrug resistance networks. To the best of our knowledge, this is the first study that reports the involvement of PDR transporters in the cell membrane of susceptible microorganisms in resistance to killer yeasts' toxins.

Repurposing Drugs to Combat Drug Resistance in Leprosy: A Review of Opportunities.

Leprosy is caused by extremely slow-growing and uncultivated mycobacterial pathogens, namely Mycobacterium leprae and M. lepromatosis. Nearly 95% of the new cases of leprosy recorded globally are found in India, Brazil, and 20 other priority countries (WHO, 2019), of which nearly two-third of the cases are reported in India alone. Currently, leprosy is treated with dapsone, rifampicin, and clofazimine, also known as multi-drug therapy (MDT), as per the recommendations of WHO since 1981. Still, the number of new leprosy cases recorded globally has remained constant in last one-decade, and resistance to multiple drugs has been documented in various parts of the world, even though relapses are rare in patients treated with MDT. Antimicrobial resistance testing against M. leprae or the evaluation of the anti-leprosy activity of new drugs remains a challenge as leprosy bacilli cannot grow in vitro. Besides, developing a new drug against leprosy through conventional drug development process is not economically attractive or viable for pharma companies. Therefore, a promising alternative is the repurposing of existing drugs/approved medications or their derivatives for assessing their anti-leprosy potential. It is an efficient method to identify novel medicinal and therapeutic properties of approved drug molecules. Any combinatorial chemotherapy that combines these repurposed drugs with the existing first-line (MDT) and second-line drugs could improve the bactericidal and synergistic effects against these notorious bacteria and can help in achieving the much-cherished goal of "leprosy-free world". This review highlights novel opportunities for drug repurposing to combat resistance to current therapeutic approaches.

Drug resistance in leprosy: an update following 70 years of chemotherapy

Leprosy is one of the oldest infectious diseases, reported for more than 2000 years. Leprosy elimination goal as a public health problem set by the World Health Organization, aiming for a global prevalence rate < 1 patient in a population of 10,000, was achieved in 2000 mainly thanks to the worldwide use of leprosy drugs starting in the 1980s and their access at no cost for patients since 1995. However, around 200,000 new cases are still reported each year, particularly in India, Brazil, and Indonesia. As with other bacteria of medical interest, antimicrobial resistance is observed in Mycobacterium leprae strains in several parts of the world, despite multidrug therapy being the recommended standard leprosy treatment to avoid resistance selection since 1982. Therefore, identifying and monitoring resistance is necessary. We provide an overview of the historical facts that led to the current drug resistance situation, the antibiotics effective against M. leprae, their mechanisms of action and resistance, and resistance detection methods. We also discuss therapeutic management of the resistant cases, new genes with potential roles in drug resistance and bacterial adaptation, new drugs under investigation, and the risk for resistance selection with the chemoprophylaxis measures.

Resistência à PQT - Marcos César Florian

Aula sobre a resistência à poliquimioterapia no tratamento da hanseníase ministrada pelo Prof. Marcos César Florian durante o 11º Simpósio Brasileiros de Hansenologia

Relapse in leprosy and drug resistance assessment in a tertiary hospital of the state of Espírito Santo, Brazil.

INTRODUCTION: Leprosy recurrence is the reappearance of the disease after treatment with current schemes and discharged for cure and may have variable incubation periods. METHODS: This is a descriptive observational study of leprosy recurrence in Espírito Santo diagnosed between January 2018 and January 2020. RESULTS: One hundred and ninety-two cases were available, of which 30 were diagnosed with leprosy recurrence. CONCLUSIONS: In 25 cases, the incubation period was 5-15 years after the first treatment, favoring bacillary persistence. In the remaining 5 cases, the disease had recurred after 15 years, pointing to reinfection as none of them exhibited drug resistance.

Mycobacterium leprae: aspectos da resistência aos fármacos na poliquimioterapia / Drug resistance in multidrug therapy for Mycobacterium leprae

Introdução: O diagnóstico da hanseníase possui números significativos que causam preocupação à saúde pública. Os casos de resistência medicamentosa nessa doença se iniciaram em meados dos anos 60 e diante do problema, a Organização Mundial da Saúde instituiu em 1981 a poliquimioterapia, associação dos antibióticos rifampicina, dapsona e clofazimina, tratamento atual de escolha. A resistência aos fármacos na hanseníase é reportada pela literatura, desvelando um obstáculo à sua eliminação. Apresentamos nessa revisão os principais aspectos da resistência medicamentosa no tratamento para hanseníase e seus impactos. Metodologia: Revisão sistemática sobre os aspectos da resistência medicamentosa utilizando a pesquisa exploratória como metodologia de abordagem. Foram pesquisados os termos resistência medicamentosa, hanseníase, recidiva, alterações genéticas e os operadores booleanos "and" e "or" na busca. Resultados e discussão: A dificuldade de tomar a medicação corretamente foi um dos principais fatores que acarretaram resistência do bacilo Mycobacterium leprae aos fármacos. Homens de países norte e sul-americanos e asiáticos foram os mais atingidos por episódios de resistência. A resistência medicamentosa é uma das principais causas de recidivas em hanseníase. O principal fármaco causador de resistência medicamentosa descrito nos trabalhos foi a dapsona (46,6%) e a maioria das alterações genéticas encontradas estão no gene rpoB; 23,2% dos registros relatados foram de resistência secundária aos fármacos e, também, sete casos de resistência múltipla a esses medicamentos. Conclusão: Os principais aspectos da resistência medicamentosa na hanseníase são os equívocos ao ingerir os medicamentos e as alterações genéticas na bactéria. Os impactos causados estão na dificuldade de refazer o tratamento, a possibilidade de nova transmissão e o aparecimento de sintomas mais graves.

Introduction: The diagnosis of leprosy has significant numbers causing public health concern. Reports of drug resistance in this disease begun in the mid-1960s and due to this problem, the World Health Organization instituted a multidrug therapy with rifampicin, dapsone, and clofazimine antibiotic association in 1981, which is currently the first-choice treatment for leprosy. Cases of drug resistance have been reported in literature, revealing an obstacle to the eradication of the disease. This paper has the purpose of presenting the key aspects and impacts of drug resistance in the treatment for leprosy. Methods: Systematic review of the drug resistance aspects using exploratory research as an approach methodology. The authors searched the terms drug resistance, leprosy, recurrence, genetic alterations, and the Boolean operators "and" and "or" between them. Results and discussion: The difficulty in taking the medication correctly was one of the key factors that led to drug resistance for Mycobacterium leprae. Men from North and South American, as well as from Asian countries, were the most affected by episodes of resistance. Drug resistance is one of the main causes of leprosy recurrences. Dapsone was the most frequently identified drug resistance in the studies (46.6%), while most of the genetic alterations were found in the rpoB gene; 23.2% of the cases were from secondary resistance episodes, and seven cases of multiple resistance were reported. Conclusion: The misconceptions when taking the treatment and the Mycobacterium leprae genetic alterations have been described as the key aspects of drugs resistance in leprosy and the impacts caused are the difficulty in redoing the treatment, the possibility of new transmission, and the appearance of more severe symptoms.

Validação de modelo murino para avaliação da atividade antibacteriana de ofloxacina e clofazimina contra o Mycobacterium leprae / Validation of a murine model for the evaluation of the antibacterial activity of ofloxacin and clofazimine against Mycobacterium leprae

A hanseníase é uma doença infectocontagiosa crônica causada pelo Mycobacterium leprae (M. leprae). Manifesta-se, principalmente, por lesões de pele com alteração de sensibilidade térmica, dolorosa e tátil, decorrentes da predileção de seu agente etiológico por células cutâneas e nervosas periféricas. No mundo, em 2018, foram reportados à Organização Mundial da Saúde (OMS), 208.619 casos novos; desses, 28.660 foram notificados no Brasil, sendo o segundo país com maior número detectado. Acredita-se que a transmissão e infecção ocorram através de secreções provenientes das vias aéreas superiores, pelo contato íntimo e prolongado de indivíduo suscetível com paciente multibacilar sem tratamento, por meio da inalação dos bacilos. O tratamento preconizado pela OMS consiste na associação de três medicamentos ­ dapsona (DDS), rifampicina (RFP) e clofazimina (CLO) ­ com o objetivo de atuar na prevenção da seleção de cepas mutantes do M. leprae resistentes a uma ou mais drogas utilizadas. A ofloxacina (OFLO) é usada como esquema alternativo ao tratamento padrão, associando-se a RFP e CLO, sendo útil nos casos de resistência medicamentosa ou intolerância a uma das drogas. O bacilo não se reproduz em meios de cultura artificiais ou celulares ­ obstáculo para o avanço em estudos do patógeno. Em 1960, Charles Shepard, demonstrou pela primeira vez a multiplicação do M. leprae em coxim plantar de camundongo imunocompetente, técnica considerada marco na pesquisa do bacilo, propiciando a verificação de sua viabilidade e uma possível resistência às drogas utilizadas no tratamento da doença. O presente estudo teve como objetivo validar o método fenotípico, por meio da inoculação do bacilo em coxim plantar posterior de camundongos imunocompetentes da linhagem BALB/c (técnica de Shepard), para detecção de sensibilidade à CLO e OFLO. Os animais foram inoculados com suspensão de bacilos obtidos de camundongos nude mouse atímicos previamente infectados com a cepa Thai53, que possui perfil genético de sensibilidade às drogas, e divididos em grupo controle (não tratado), RFP (10mg/kg), CLO (50mg/kg) e OFLO (150mg/kg). Após cinco meses de inoculação e tratamento, os animais foram eutanasiados, e os coxins excisados para contagem do número de bacilos e análise histopatológica. No grupo controle, o número de bacilos recuperados foi maior que 1,0x105 /coxim, compatível com multiplicação bacilar; a análise histopatológica evidenciou infiltrado inflamatório intenso com bacilos agrupados ou em globias, íntegros e bem corados. Nos grupos tratados, não foi observada evidência de multiplicação bacilar, mostrando sensibilidade às drogas testadas; a análise histopatológica evidenciou infiltrado inflamatório discreto a moderado com ausência de bacilos. A técnica de Shepard é considerada padrão ouro para a multiplicação do bacilo, sendo fundamental para validar a identificação de novos alvos de mutação em genes determinantes da ação das drogas anti-hansênicas. Os resultados gerados no presente estudo terão grande impacto, principalmente para compreender a falha terapêutica em pacientes com recidiva que não apresentaram perfil de resistência pelos mecanismos moleculares até o momento descritos para a doença.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae). It is mainly manifested by skin lesions with changes in thermal, sensory and tactile sensitivity resulting from the predilection of its etiologic agent by skin and peripheral nerve cells. The World Health Organization (WHO) reported 208,619 new cases in 2018 worldwide; among these, 28,660 were reported in Brazil, the second country with the highest number detected. It is believed that transmission and infection occur by inhaling bacilli through the upper airways, while in close and prolonged contact of a susceptible individual with an untreated multibacillary patient. The treatment recommended by the WHO consists of the combination of three drugs -dapsone (DDS), rifampicin (RFP) and clofazimine (CLO) - in order to prevent the selection of mutant M. leprae strains resistant to one or more drugs. Ofloxacin (OFLO) is used as an alternative regimen to standard treatment, in association with RFP and CLO, being useful in cases of drug resistance or intolerance to one of the drugs. The bacillus does not reproduce in artificial or cellular culture media - an obstacle to progress in studies of the pathogen. In 1960, Charles Shepard, demonstrated for the first time the multiplication of M. leprae in an immunocompetent mouse footpad, a technique considered a landmark in the bacillus research, enabling the verification of its viability and a possible resistance to drugs used in the treatment of the disease. The present study aimed to validate the phenotypic method, by inoculating the bacillus in the hind footpads of immunocompetent BALB/c mice strain (Shepard's technique), to detect sensitivity to CLO and OFLO. The animals were inoculated with a suspension of bacilli obtained from athymic nude mouse previously infected with the Thai-53 strain, a sensitive strain. Mice were divided into a control (untreated), RFP (10mg / kg), CLO (50mg / kg) and OFLO (150mg / kg) groups. After five months of inoculation and treatment, the animals were euthanized and the foopads excised for enumeration of bacilli and histopathological analysis. In the control group, the number of bacilli recovered was greater than 1.0x105 /footpad, compatible with bacillary multiplication; histopathological analysis showed an intense inflammatory infiltrate with well stained grouped bacilli and globi. In the treated groups, there was no evidence of bacillary multiplication, showing sensitivity to the drugs tested; histopathological analysis showed mild to moderate inflammatory infiltrate with no bacilli. The Shepard technique is considered the gold standard for bacillus multiplication, being essential to validate the identification of new mutation targets in genes that determine anti-leprosy drugs activity. The results generated in the present study will have a great impact, mainly to understand the therapeutic failure in patients with recurrence who did not present a resistance profile using molecular mechanisms described so far for the disease.

Levantamento de dados para estudo dos fatores associados à falha terapêutica em hanseníase / Data collection to study the factors associated with failure leprosy therapy

A Hanseníase é uma doença infectocontagiosa de caráter crônico, evolução lenta, causada pelo Mycobacterium leprae (M. leprae). A transmissão ocorre por meio do trato respiratório, e para o desenvolvimento da doença existe a necessidade da susceptibilidade, além do contato íntimo e prolongado. Para fins terapêuticos a Organização Mundial da Saúde (OMS) traz uma classificação mais simples que é baseada no número de lesões cutâneas. Os casos com até cinco lesões são considerados paucibacilares e aqueles com mais de cinco lesões são multibacilares. Apesar da implantação da poliquimioterapia (PQT) pela OMS ter sido um importante avanço técnico na história do controle da doença, em 2019 ainda foram notificados 202.185 novos casos no mundo, sendo o Brasil o segundo em concentração de casos. Um indicador importante para o controle da hanseníase são as taxas de retratamento, definido como nova notificação de hanseníase em paciente que já tenha recebido tratamento anterior, suas causas incluem abandono, insuficiência terapêutica, falência terapêutica, alteração de esquema por erro diagnóstico e recidiva. Embora um grande número de casos de recidivas seja detectado no Brasil, apenas 8,4%, 13,3% e 1,9% dos casos podem ser explicados por mutações que sabidamente conferem resistência bacilar aos medicamentos utilizados na PQT: rifampicina (RFP), dapsona (DDS) e ofloxacina (OFLO), respectivamente. Além dos aspectos relacionados ao patógeno, a contribuição do hospedeiro para esse cenário, apesar de pouco estudada, deve ser de grande importância. No geral a resposta ao medicamento é variável entre indivíduos, ocasionando falta de eficácia farmacológica ou reação adversas, em partes esses eventos podem ser explicados pela farmacogenética. Conhecer fatores genéticos que interferem no metabolismo dos medicamentos pode contribuir para melhores resultados terapêuticos. Dentre os desafios para atingir a eliminação da hanseníase estão a ausência de novas ferramentas de diagnóstico e de entendimento das causas associadas a recidiva e à não adesão a PQT, uma vez que a resistência medicamentosa explica pouco da reativação da doença, deste modo, o presente estudo teve como finalidade constituir banco de dados em hanseníase para estudos de associação do tipo caso-controle sobre os fatores associados com a falha terapêutica da PQT convencional. Dos 240 prontuários avaliados, 119 foram classificados como casos de falência terapêutica ou recidiva e 121 como sucesso terapêutico, aqui denominados como controles, a maioria dos pacientes era do sexo masculino, branco e procedente do estado de São Paulo; Em relação à faixa etária de diagnóstico, 18% foram diagnosticados com idade entre 40 e 49 anos, enquanto nos controles 14% tiveram diagnóstico com idade inferior a 19 anos; quanto à forma clínica da doença, 59% dos casos e 47% dos controles foram classificados como virchoviano. Dentre os casos de falência terapêutica ou recidiva, a resistência molecular explicou apenas 5,8 % dos casos de retratamento. Esse dado reforça a urgência de estudos que esclareçam as causas da falha terapêutica em hanseníase, contribuindo assim para o estabelecimento de medidas que visem o alcance de melhores índices relacionados aos desfechos terapêuticos.(AU)

Leprosy is a chronic infectious disease with insidious evolution, caused by Mycobacterium leprae (M. leprae). Transmission occurs through the respiratory tract, and the onset of the disease depends on susceptibility, in addition to intimate and prolonged contact with untreated patients. For therapeutic purposes, the World Health Organization's (WHO) classification is based on the number of skin lesions. Cases with up to five lesions are considered paucibacillary and those with more than five lesion are multibacillary. Although the implementation of multidrugtherapy (MDT) by WHO was an important technical advance in the history of disease control. In 2019, 202,185 new cases were reported in the world, with Brazil the second in the highest number of cases. An important indicator for the control of leprosy is retreatment rate, defined as a new notification of leprosy in a patient who has already received previous treatment. Its causes include abandonment, therapeutic failure, , alteration of the regimen due to diagnostic error and relapse. Although a large number of cases of relapses are detected in Brazil, only 8.4%, 13.3% and 1.9% of cases can be explained by mutations that are known to confer bacillary resistance to drugs used in the MDT: rifampicin (RFP), dapsone (DDS) and ofloxacin (OFLO), respectively. In addition to aspects related to the pathogen, the host's contribution to this scenario, although little studied, is highly important. In general, the response to the drug treatment is variable between individuals, causing a lack of pharmacological efficacy or adverse reactions. , These events may be explained by pharmacogenetics. Knowing genetic factors that interfere with drug metabolism can contribute to better therapeutic results. Among the challenges to achieve leprosy elimination are the absence of new diagnostic tools and understanding of the causes associated with relapse and non-adherence to MDT, since drug resistance explains little about the reactivation of the disease. Thus, the present study aimed at constituting a leprosy database for case-control association studies on factors associated with conventional MDT therapeutic failure. Of the 240 medical records evaluated, 119 were classified as cases of therapeutic failure or relapse and 121 as therapeutic success, here referred to as controls. The majority of patients were male, white and from the state of São Paulo. Regarding the age of diagnosis, 18% were diagnosed between 40 and 49 years, while in controls, 14% were diagnosed under 19 years; as to the clinical form of the disease, 59% of the cases and 47% of the controls were classified as lepromatous. Among the cases of therapeutic failure or relapse, molecular resistance explained only 5.8% of retreatment cases. This data reinforces the urgency of studies that clarify the causes of therapeutic failure in leprosy, thus contributing to the establishment of measures aimed at achieving better therapeutic outcomes(AU).

Mutações não validadas em rpoB - potencialmente associadas à resistência à rifampicina / Non-validated mutations in rpoB - potentially associated with resistance to rifampicin

Introdução Hanseníase é uma doença infecciosa crônica, causada pelo Mycobacterium leprae. Por causar incapacidades físicas devido às lesões neurais, ainda hoje, é um grave problema de saúde pública no Brasil. Desde a década de 80, o tratamento é realizado por poliquimioterapia (PQT): dapsona, rifampicina e clofazimina. A ofloxacina é a droga alternativa mais amplamente utilizada. Mutações em regiões determinantes de droga resistência (DRDR) nos genes folp1, rpoB e gyrA estão relacionadas com resistência a dapsona, rifampicina e ofloxacina, respectivamente. Desde a década de 60 ocorrem relatos de M. leprae resistentes a uma das drogas ou até mesmo multidrogas resistentes. Objetivos Analisar as mutações não validadas no gene rpoB, a droga bactericida do esquema PQT, e comparar com o que já foi validado na literatura. Materiais e Métodos Isolados de M. leprae que apresentaram mutações no gene rpoB fora das regiões determinantes de resistência à rifampicina foram selecionados do banco de amostras testadas anteriormente por sequenciamento direto na rotina de investigação de resistência em hanseníase do ILSL, no período entre 2015 e 2020. Resultados Um total de 1396 amostras de isolados de pacientes do Instituto Lauro de Souza Lima foram analisadas. Dentre elas, 22 amostras apresentaram mutações em códons já descritos na literatura e 53 amostras apresentaram algum tipo de alteração fora dos códons comumente investigados. Discussão No presente estudo, diversas mutações entre os códons 411 e 530 do gene rpoB foram encontradas. Algumas delas já foram descritas na literatura, enquanto outras não foram encontradas para que fosse possível ter uma base comparativa. Conclusão São necessários estudos mais aprofundados sobre mutações não DRDRs e, até mesmo, novos mecanismos de resistência para elucidar os casos de retratamento. Além disso, a implantação de ações mais eficientes de saúde pública é de fundamental importância para o controle da hanseníase.

Introduction Leprosy is a chronic infectious disease, caused by Mycobacterium leprae. It causes physical disabilities due to neural injuries and it remains as a serious public health problem in Brazil. Since the 1980s, treatment has been carried out by multidrug therapy (MDT): dapsone, rifampicin and clofazimine. Mutations in drug resistance-determining regions (DRDR) in the folp1, rpoB and gyrA genes are related to resistance to dapsone, rifampicin and ofloxacin, respectively. Since the 1960s, there have been reports of M. leprae being resistant to one of the drugs or even multidrug resistant. Objectives To analyze mutations not validated in the rpoB gene and compare with what has already been validated in the literature. Materials and Methods Isolates of M. leprae that showed mutations in the rpoB gene outside the rifampin resistance determining regions were selected from the sample bank tested previously by direct sequencing in the ILSL leprosy resistance investigation routine, between 2015 and 2020. Results Between 2015 and 2020, a total of 1396 samples of isolates from patients in the Lauro de Souza Lima Institute were analyzed. Among them, 22 samples presented mutations in codons already described in the literature and 53 samples presented some type of mutation outside these codons. Discussion In the present work, several mutations between codons 411 and 530 of the rpoB gene were found. Some of them have already been described in the literature, while others have not been found, and could not be compared. Conclusion Further studies on non-DRDR mutations and even new resistance mechanisms are needed to elucidate retreatment cases. In addition, the implementation of more efficient public health actions is of fundamental importance for the control of leprosy.

Relapse in leprosy and drug resistance assessment in a tertiary hospital of the state of Espírito Santo, Brazil

Abstract INTRODUCTION: Leprosy recurrence is the reappearance of the disease after treatment with current schemes and discharged for cure and may have variable incubation periods. METHODS: This is a descriptive observational study of leprosy recurrence in Espírito Santo diagnosed between January 2018 and January 2020. RESULTS: One hundred and ninety-two cases were available, of which 30 were diagnosed with leprosy recurrence. CONCLUSIONS: In 25 cases, the incubation period was 5-15 years after the first treatment, favoring bacillary persistence. In the remaining 5 cases, the disease had recurred after 15 years, pointing to reinfection as none of them exhibited drug resistance.

Clofazimine, a Promising Drug for the Treatment of Babesia microti Infection in Severely Immunocompromised Hosts.

BACKGROUND: Persistent and relapsing babesiosis caused by Babesia microti often occurs in immunocompromised patients, and has been associated with resistance to antimicrobial agents such as atovaquone. Given the rising incidence of babesiosis in the United States, novel drugs are urgently needed. In the current study, we tested whether clofazimine (CFZ), an antibiotic used to treat leprosy and drug-resistant tuberculosis, is effective against B. microti. METHODS: Mice with severe combined immunodeficiency were infected with 107B. microti-infected erythrocytes. Parasites were detected by means of microscopic examination of Giemsa-stained blood smears or nested polymerase chain reaction. CFZ was administered orally. RESULTS: Uninterrupted monotherapy with CFZ curtailed the rise of parasitemia and achieved radical cure. B. microti parasites and B. microti DNA were cleared by days 10 and 50 of therapy, respectively. A 7-day administration of CFZ delayed the rise of parasitemia by 22 days. This rise was caused by B. microti isolates that did not carry mutations in the cytochrome b gene. Accordingly, a 14-day administration of CFZ was sufficient to resolve high-grade parasitemia caused by atovaquone-resistant B. microti parasites. CONCLUSIONS: Clofazimine is effective against B. microti infection in the immunocompromised host. Additional preclinical studies are required to identify the minimal dose and dosage of CFZ for babesiosis.

Resistencia a los medicamentos del Mycobacterium Leprae detectados en cultivo de almohadilla plantar de ratón entre 1997 y 2013 en Malasia / No disponible

Antecedentes: Después de tres décadas de implementación de la multiterapia (MDT), consistente en una combinación de rifampicina, dapsona y clofazimina, en Malasia la aparición de resistencia farmacológica del Mycobacterium leprae constituye una preocupación, ya que puede llevar al fracaso del tratamiento y la recidiva de la enfermedad. Objetivos: Determinar el modelo de resistencia farmacológica del M. leprae en Malasia. Métodos: Se analizaron los cultivos en almohadilla plantar de ratón (MFP) de todas las biopsias cutáneas de pacientes con lepra borderline lepromatosa y lepra lepromatosa enviados a la Unidad de la Lepra, Laboratorio Nacional de Salud Publica, Sungai Buloh, Malasia, entre 1997-2013. Resultados: Se realizaron 651 cultivos MFP. La edad media de los pacientes fue de 41 anos (rango: 6-88). La proporción varón/hembra era de 3·8:1. Cuatrocientos cuarenta y cuatro pacientes (69·1%) eran malayos. La proporción de M. leprae positivo en cultivo era del 66·6% (433 of 651). El Índice Bacteriologico (IB) y el Índice Morfológico (IM) promedios para los cultivos positivos fue de 3·7 and 2·8 respectivamente. El IB y el IM de los que no crecieron en la MFP eran significativamente menores que los que presentaban cultivos positivos (P < 0·001). La dapsona presento el mayor índice de resistencia del 55% (238 of 433). Sin embargo, el elevado grado de resistencia a la dapsona (0·01%) fue de 6·24%. Hubo 407 MFP con rifampicina 0·003% y 12 (2·9%) resultaron resistentes a la misma. La clofazimina presento el menor grado de resistencia intermedia (0·001%) que fue del 0·2% (1 of 429). No había diferencias significativas entre el patrón de resistencia y género o nacionalidad de los pacientes. Conclusiones: Mas de la mitad de los cultivos MFP presentaron resistencia de baja intensidad a la dapsona; menos del 3% eran resistentes a la rifampicina y la resistencia a la clofazimina resulto muy baja

Background: After three decades of implementing multidrug therapy (MDT) consisting of rifampicin, dapsone and clofazimine in Malaysia, the drug resistance pattern of Mycobacterium leprae is a growing concern as it may lead to failure of treatment and relapse of disease. Objective: To determine the drug resistance patterns of M. leprae in Malaysia. Methods: Mouse footpad (MFP) culture of all skin biopsy samples from patients with borderline lepromatous and lepromatous leprosy sent to the Leprosy Unit, National Public Health Laboratory, Sungai Buloh, Malaysia between 1997-2013 were retrospectively studied. Results: There were 651 MFP cultures performed. The mean age of patients was 41 years old (range: 6-88). The male: female ratio was 3·8:1. Four hundred and forty four patients (69·1%) were Malaysian. The rate of positive M. leprae culture was 66·6% (433 of 651). The mean Bacteriological Index (BI) and median Morphological Index (MI) for those with positive culture were 3·7 and 2·8 respectively. The mean BI and MI of those which failed to grow in the MFP were significantly lower than those with positive cultures (P < 0·001). Dapsone has the highest resistance rate of 55% (238 of 433). Nevertheless, high degree dapsone resistance (0·01%) was 6·24%. There were 407 MFP tests using rifampicin 0·003% and 12 (2·9%) were resistant to it. Clofazimine has the lowest intermediate degree (0·001%) resistance rate of 0·2% (1 of 429). There were no significant differences between the drug resistance pattern and the gender or the nationality of the patients. Conclusion: More than half of our positive MFP cultures showed low-level resistance to dapsone; less than 3% were resistant to rifampicin, and clofazimine resistance remained very low