Mecanismos de expressão de resistência aos antibióticos e saúde pública / Mechanisms of expression of resistance to antibiotics and public health / Mecanismos de expresión de la resistencia a los antibióticos y salud pública

Com o avanço da medicina e o aumento do uso de antimicrobianos, a resistência microbiana vem se tornando um problema sério na saúde pública. Para que uma bactéria se torne resistente, são necessários vários fatores, entre eles, o uso indiscriminado e prolongado de antimicrobianos e as resistências intrínsecas e adquiridas. Nesse contexto, o objetivo do trabalho foi explorar os mecanismos de ação dos antimicrobianos, de resistência e a sua importância na saúde pública. Foram utilizadas para a presente pesquisa, as bases de dados Pubmed, Google acadêmico e Scielo. Segundo a Organização Mundial da Saúde define-se resistência ao antibiótico quando o mesmo não produz mais efeito. A inserção cada vez mais frequente de antimicrobianos favorece a resistência, onde provocam uma pressão seletiva sobre os microrganismos, tornando-os resistentes a diversas drogas. O uso indiscriminado de antimicrobianos é o principal fator de resistência microbiana, assim como o uso de antimicrobianos sem exame de cultura e teste de sensibilidade. Neste sentido, conclui-se que é de suma importância a atualização de protocolos que contenham os mecanismos de resistência bacteriana a fim de minimizar o uso indiscriminado de antimicrobianos, assim como capacitar os profissionais da saúde para este problema na saúde pública.

With the advance of medicine and the increase in the use of antimicrobials, microbial resistance has become a serious problem in public health. For a bacterium to become resistant, several factors are necessary, among them, the indiscriminate and prolonged use of antimicrobials and the intrinsic and acquired resistance. In this context, the objective of the work was to explore the mechanisms of action of antimicrobials, resistance and their importance in public health. Pubmed, Google academic and Scielo databases were used for this research. According to the World Health Organization, resistance to antibiotics is defined when it no longer has an effect. The increasingly frequent insertion of antimicrobials favors resistance, where they put selective pressure on microorganisms, making them resistant to various drugs. The indiscriminate use of antimicrobials is the main factor of microbial resistance, as well as the use of antimicrobials without culture examination and sensitivity test. In this sense, it is concluded that it is extremely important to update protocols that contain the mechanisms of bacterial resistance in order to minimize the indiscriminate use of antimicrobials, as well as to train health professionals for this problem in public health.

Con los avances de la medicina y el mayor uso de antimicrobianos, la resistencia microbiana se ha convertido en un grave problema de salud pública. Para que una bacteria se vuelva resistente son necesarios varios factores, entre ellos, el uso indiscriminado y prolongado de antimicrobianos y la resistencia intrínseca y adquirida. En este contexto, el objetivo de este trabajo fue explorar los mecanismos de acción de los antimicrobianos, la resistencia y su importancia en la salud pública. Para esta investigación se utilizaron las bases de datos Pubmed, Google Scholar y Scielo. Según la Organización Mundial de la Salud, la resistencia a un antibiótico se define cuando deja de producir efecto. El uso cada vez más frecuente de antimicrobianos favorece la resistencia, ya que provocan una presión selectiva sobre los microorganismos, haciéndolos resistentes a varios fármacos. El uso indiscriminado de antimicrobianos es el principal factor de resistencia microbiana, así como el uso de antimicrobianos sin pruebas de cultivo y sensibilidad. En este sentido, se concluye que es de suma importancia actualizar los protocolos que contienen los mecanismos de resistencia bacteriana para minimizar el uso indiscriminado de antimicrobianos, así como capacitar a los profesionales de la salud para este problema en la salud pública.

Resistencia antirretroviral en pacientes con virus de inmuno- deficiencia humana en Hospital Nacional Mario Catarino Rivas / Resistance to antiretroviral drugs in patients with human immunodeficiency virus in Mario Catarino Rivas National Hospital

Introducción: La terapia antirretroviral de primera línea utilizada en el país desde hace varios años, consiste en un inhibidor de la transcriptasa reversa no nucleósido con dos inhibidores de la transcriptasa reversa nucleósidos, está asociada al fallo terapéutico y se ha reportado resis- tencia a la misma. Objetivo: conocer la resistencia a la terapia antirretroviral de primera línea en pacientes tratados por Virus de Inmunodeficiencia Humana en Hospital Nacional Mario Catarino Rivas desde octubre 2016 al 2017. Pacientes y métodos: Investigación observacio- nal, descriptiva; tipo cohorte transversal, retrospectiva. Población de 313 pacientes a quienes se le realizó prueba de genotipo, de los cuales se tomaron como muestra 291 pacientes distri- buidos por grupos: sin previa exposición a antirretrovirales, pediátricos, con 12 meses de trata- miento y 48 o más meses de tratamiento a quienes se les realizó prueba de genotipo. Resulta- dos: Hubo amplificación en el 52% (152) de los pacientes, de los cuales el 56% (85) presentó resistencia a tratamiento antirretroviral, con prevalencia de resistencia de inhibidores de trans- criptasa reversa análogo de nucleósidos del 75% (64), los inhibidores de transcriptasa reversa no nucleósidos (ITRNN) con 89% (76) y los inhibidores de proteasa del 15% (13). Se encontró una prevalencia de resistencia primaria del 19% en pacientes de diagnóstico nuevo. Conclu- sión: Se recomienda el cambio de primera línea de terapia antirretroviral ya que se identifica- ron mutaciones de resistencia a los ITRNN en un 91% en los pacientes con diagnóstico recien- te y sin exposición a ARV. La OMS recomienda retirar los ITRNN como primera línea e incluir fármacos con mejor barrera genética, cuando los niveles de resistencia para los ITRNN sean >10%...(AU)

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.

Quinolinotriazole antiplasmodials via click chemistry: synthesis and in vitro studies of 7-Chloroquinoline-based compounds

Malaria is nowadays one of the most serious health concerns in a global scale and, although there is an evident increase in research studies in this area, pointed by the vast number of hits and leads, it still appears as a recurrent topic every year due to the drug resistance shown by the parasite exposing the urgent need to develop new antimalarial medications. In this work, 38 molecules were synthesized via copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) or "click" chemistry, following different routes to produce 2 different organic azides, obtained from a 4,7 dicholoquinoline, reacted with 19 different commercially available terminal alkynes. All those new compounds were evaluated for their in vitro activity against the chloroquine resistant malaria parasite Plasmodium falciparum (W2). The cytotoxicity evaluation was accomplished using Hep G2 cells and SI index was calculated for every molecule. Some of the quinoline derivatives have shown high antimalarial activity, with IC50 values in the range of 1.72-8.66 µM, low cytotoxicity, with CC50>1000 µM and selectivity index (SI) in the range of 20-100, with some compounds showing SI>800. Therefore, the quinolinotriazole hybrids could be considered a very important step on the development of new antimalarial drugs

Aspectos associados à drogarresistência em pessoas com Tuberculose/HIV: revisão integrativa / Aspectos relacionados con la drogorresistencia en personas con tuberculosis/VIH: revisión integradora / Aspects associated with drug resistance in people with tuberculosis/HIV: an integrative review

Resumo Objetivo: Analisar as produções científicas acerca dos aspectos associados à drogarresistência em pessoas com coinfecção Tuberculose/HIV. Métodos: Revisão integrativa de literatura, realizada nas bases de dados CINAHL, LILACS, SciELO, Web of Science, SCOPUS, MEDLINE e COCHRANE. Utilizaram-se dos descritores HIV, Tuberculose e Resistência a múltiplos medicamentos, em português, inglês e espanhol. Encontraram-se 1.177 artigos e selecionaram-se 19, excluíram-se 1.158, 41 duplicados e 1.117, por não atenderem à pergunta de pesquisa e abordarem outras temáticas, como: coinfecção do HIV e pneumonia; impacto da multirresistência na vida de pessoas com coinfecção, destacando-se a mortalidade; testes diagnósticos de multirresistência aos fármacos; e associação entre HIV e tuberculose meníngea. Resultados: Os dados obtidos foram organizados em três categorias temáticas: Aspectos clínicos, destacando-se: infecção pelo HIV, hipoalbuminemia, carga elevada do bacilo; Aspectos relacionados aos fármacos, incluindo abandono do tratamento, não adesão à terapia, tratamento prévio para tuberculose, má absorção de medicamentos, efeitos adversos causados pela terapia antirretroviral, interação entre os tratamentos de ambas as infecções; e Aspectos sociais, sinalizando-se hospitalizações, convivência com outras pessoas com bacilos multirresistentes, privação de liberdade, atraso no diagnóstico e início tardio do tratamento. Conclusão: Os principais aspectos identificados foram o abandono da terapêutica, tratamento prévio para tuberculose e intervenção inadequada, tais resultados, também, podem estender-se às pessoas que não apresentam coinfecção. Enfatiza-se a importância desta revisão para instigar novas pesquisas, com destaque para estratégias com foco na identificação precoce de pessoas com multirresistência, prevenção e incentivo à adesão ao tratamento.

Resumen Objetivo: Analizar las producciones científicas sobre los aspectos relacionados con la drogorresistencia en personas con coinfección tuberculosis/VIH. Métodos: Revisión integradora de literatura, realizada en las bases de datos CINAHL, LILACS, SciELO, Web of Science, SCOPUS, MEDLINE y COCHRANE. Se utilizaron los descriptores VIH, tuberculosis y resistencia a múltiples medicamentos, en portugués, inglés y español. Se encontraron 1.177 artículos, de los que se seleccionaron 19 y se excluyeron 1.158, 41 duplicados y 1.117 por no abordar la pregunta de la investigación y tratar otros temas, como: coinfección de VIH y neumonía; impacto de la multirresistencia en la vida de personas con coinfección, con énfasis en la mortalidad; pruebas diagnósticas de multirresistencia a los fármacos, y relación entre VIH y tuberculosis meníngea. Resultados: Los datos obtenidos fueron organizados en tres categorías temáticas: aspectos clínicos, con énfasis en: infección por VIH, hipoalbuminemia, carga del bacilo elevada; aspectos relacionados con los fármacos, como abandono del tratamiento, no adherencia al tratamiento, tratamiento previo para tuberculosis, mala absorción de medicamentos, efectos adversos causados por el tratamiento antirretroviral, interacción entre los tratamientos de ambas infecciones; y aspectos sociales, con foco en internaciones, convivencia con otras personas con bacilos multirresistentes, privación de la libertad, retraso en el diagnóstico e inicio tardío del tratamiento. Conclusión: Los principales aspectos identificados fueron el abandono del tratamiento, el tratamiento previo para tuberculosis y la intervención inadecuada. Estos resultados también pueden extenderse a las personas que no presentan coinfección. Se resalta la importancia de esta revisión para estimular nuevas investigaciones, con énfasis en estrategias centradas en la identificación temprana de personas con multirresistencia, prevención e incentivo para adherir al tratamiento.

Abstract Objective: To analyze scientific productions on aspects associated with drug resistance in people with tuberculosis (TB)/HIV coinfection. Methods: Integrative literature review performed in the CINAHL, LILACS, SciELO, Web of Science, SCOPUS, MEDLINE and COCHRANE databases. The following descriptors were used in Portuguese, English and Spanish: HIV, Tuberculosis and Multidrug resistance. In total, 1,177 articles were found and 19 were selected; 1,158 were excluded, of which 41 were duplicates and 1,117 did not answer the research question and addressed other topics, namely: HIV and pneumonia coinfection; impact of multidrug resistance on the lives of people with coinfection, with emphasis on mortality; diagnostic tests for multidrug resistance; and association between HIV and meningeal tuberculosis. Results: Data were organized into three thematic categories, as follows: Clinical aspects, highlighting: HIV infection, hypoalbuminemia, elevated bacillus load; drug-related aspects, including treatment abandonment, non-adherence to therapy, previous treatment for tuberculosis, drug malabsorption, adverse effects caused by antiretroviral therapy, interaction between treatments for both infections; and social aspects, including hospitalizations, living with other people with multidrug-resistant bacilli, deprivation of liberty, delayed diagnosis and late start of treatment. Conclusion: The main aspects identified were abandonment of therapy, previous treatment for tuberculosis and inadequate intervention, and these results may also extend to people who do not have coinfection. This review is important to instigate new research, with emphasis on strategies focused on the early identification of people with multidrug resistance, prevention and encouragement of adherence to treatment.

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents / Atividade anti-helmíntica do acetato de carvacrila nanoencapsulado sobre nematoides gastrintestinais de ovinos e toxicidade em roedores

Abstract The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.

Differences in protein expression associated with ivermectin resistance in Caenorhabditis elegans / Diferenças na expressão de proteínas associadas à resistência à ivermectina em Caenorhabditis elegans

Abstract The indiscriminate administration of synthetic anthelmintics such as ivermectin contributes to the selection of subpopulations capable of resisting the drugs' effects. To understand the mechanisms of ivermectin resistance in Caenorhabditis elegans, this study attempted to identify molecular targets. C. elegans lineages that were sensitive and resistant to ivermectin were used. Collected nematodes were added to an extraction buffer and macerated in liquid nitrogen for protein extraction. The extracted proteins were separated according to molecular weight by SDS-PAGE to verify their integrity. Subsequently, proteins from both lineages were separated using two-dimensional electrophoresis. The gels were analyzed and the relevant spots were excised and identified by mass spectrometry (NanoESI-Q-TOF and MASCOT®) and subsequently assessed by GO enrichment and STRING® analyses. The increased expression of proteins associated with high metabolic activity, such as ATP-2 and ENOL-1, which are responsible for ATP synthesis, was observed. Furthermore, proteins with involvement in mediating muscular function (MLC-1, ACT-1, and PDI-2), signaling (FAR-1 and FAR-2), and embryo development (VHA-2) were identified. Protein interaction analysis indicated that the majority of the identified proteins in the resistant lineages participated in the same reaction triggered by ivermectin.

Resumo A administração indiscriminada de anti-helmínticos sintéticos, como a ivermectina, contribui para a seleção de subpopulações capazes de resistir ao efeito das drogas. Para entender os mecanismos de resistência à ivermectina em Caenorhabditis elegans, este estudo visou identificar alvos moleculares. Portanto, linhagens de C. elegans sensíveis e resistentes à ivermectina foram utilizadas. Os nematóides coletados foram adicionados ao tampão de extração e macerados em nitrogênio líquido para obtenção das proteínas. As proteínas extraídas foram separadas por peso molecular em SDS-PAGE para verificar sua integridade. Posteriormente, as proteínas de ambas as linhagens foram separadas por eletroforese bidimensional. Os géis foram analisados, os spots relevantes foram excisados e identificados por espectrometria de massa (NanoESI-Q-TOF e MASCOT®), em seguida, analisados ​​em seus termos de GO e STRING®. A expressão aumentada de proteínas associadas à alta atividade metabólica, como as proteínas ATP-2 e ENOL-1, responsáveis ​​pela síntese de ATP, foi observada. Além disso, foram identificadas as proteínas responsáveis ​​pelo controle da função muscular (MLC-1, ACT-1 e PDI-2), sinalização (FAR-1 e FAR-2) e desenvolvimento embrionário (VHA-2). A análise das interações proteicas indicou que a maioria das proteínas identificadas na cepa resistente participa da mesma reação desencadeada pela ivermectina.

Anti-interleukin-1 treatment among patients with familial Mediterranean fever resistant to colchicine treatment. Retrospective analysis

ABSTRACT BACKGROUND: Up to 5% of familial Mediterranean fever (FMF) cases are unresponsive to colchicine, through resistance, side effects and toxicity. Anakinra is an alternative treatment for FMF patients whose disease remains uncontrolled with colchicine. We aimed to evaluate anti-interleukin-1 treatment regarding clinical findings, laboratory parameters and quality of life (QoL) among FMF patients presenting resistance and toxicity towards colchicine. DESIGN AND SETTING: Descriptive observational study at the rheumatology clinic, Adnan Menderes University Medical School, Aydın, Turkey. METHODS: Among the patients included, age, sex, MEFV genotypes, acute-phase reactants, hepatic/renal function tests, average colchicine dose, disease duration, attack frequency, attack duration, disease severity, proteinuria, amyloidosis and QoL were evaluated. Colchicine resistance was defined as > 6 typical episodes/year or > 3 per 4-6 months. Kolmogorov-Smirnov, Friedman and two-way analysis of variance tests were used for statistical analyses. RESULTS: Between 2015 and 2017, 14 FMF patients receiving anakinra were enrolled. The mean colchicine dose was 1.7 ± 0.3 mg/day before use of anakinra. Ten patients were attack-free after treatment, while three showed reductions of at least 50% in attack frequency, attack duration and disease severity. Proteinuria levels in all patients with renal amyloidosis decreased after treatment. QoL among patients with renal amyloidosis differed significantly from QoL among non-amyloidosis patients. Mean visual analogue scale scores significantly improved in both groups after use of anakinra. CONCLUSIONS: Use of anakinra reduced attack frequency and proteinuria and acute-phase reactant levels, and improved QoL, with only a few uncomplicated side effects among colchicine-resistant or intolerant FMF patients. Injection-site reactions of severity insufficient to require discontinuation of treatment were seen.

Antimony resistance in Leishmania (Viannia) braziliensis clinical isolates from atypical lesions associates with increased ARM56/ARM58 transcripts and reduced drug uptake

BACKGROUND In addition to the limited therapeutic arsenal and the side effects of antileishmanial agents, drug resistance hinders disease control. In Brazil, Leishmania braziliensis causes atypical (AT) tegumentary leishmaniasis lesions, frequently refractory to treatment. OBJECTIVES The main goal of this study was to characterise antimony (Sb)-resistant (SbR) L. braziliensis strains obtained from patients living in Xakriabá indigenous community, Minas Gerais, Brazil. METHODS The aquaglyceroporin 1-encoding gene (AQP1) from L. braziliensis clinical isolates was sequenced, and its function was evaluated by hypo-osmotic shock. mRNA levels of genes associated with Sb resistance were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Atomic absorption was used to measure Sb uptake. FINDINGS Although clinical isolates presented delayed recovery time in hypo-osmotic shock, AQP1 function was maintained. Isolate 340 accumulated less Sb than all other isolates, supporting the 65-fold downregulation of AQP1 mRNA levels. Both 330 and 340 isolates upregulated antimony resistance marker (ARM) 56/ARM58 and multidrug resistant protein A (MRPA); however, only ARM58 upregulation was an exclusive feature of SbR field isolates. CA7AE seemed to increase drug uptake in L. braziliensis and represented a tool to study the role of glycoconjugates in Sb transport. MAIN CONCLUSIONS There is a clear correlation between ARM56/58 upregulation and Sb resistance in AT-harbouring patients, suggesting the use of these markers as potential indicators to help the treatment choice and outcome, preventing therapeutic failure.

Lack of quadruple and quintuple mutant alleles associated with sulfadoxine-pyrimethamine resistance in Plasmodium vivax isolates from Brazilian endemic areas

BACKGROUND AND OBJECTIVE Brazil is responsible for a large number of Plasmodium vivax cases in America. Given the emergence of P. vivax parasites resistant to chloroquine and the effectiveness of antifolates in vivax malaria treatment together with a correlation between mutations in P. vivax dhfr and dhps genes and SP treatment failure, the point mutations in these genes were investigated. METHODS Blood samples from 54 patients experiencing vivax malaria symptomatic episodes in the Amazonian Region were investigated. Genomic DNA was extracted using a DNA extraction kit (QIAGENTM). Nested polymerase chain reaction (PCR) amplification was carried out followed by Sanger sequencing to detect single nucleotide polymorphisms (SNPs). FINDINGS All tested isolates showed non-synonymous mutations in pvdhfr gene: 117N (54/54, 100%) and 58R (25/54, 46%). Double mutant allele 58R/117N (FRTNI, 28%) was the most frequent followed by triple mutant alleles (58R/117N/173L, FRTNL, 11%; 58R/61M/117N, FRMNI, 5% 117N/173L, FSTNL, 4%) and quadruple mutant allele (58R/61M/117N/173L, FRMNL, 2%). A single mutation was observed at codon C383G in pvdhps gene (SGKAV, 48%). CONCLUSION No evidence of molecular signatures associated with P. vivax resistance to SP was observed in the Brazilian samples.

Resistencia a medicamentos en mycobacterium tuberculosis: contribución de mecanismos constitutivos y adquiridos / Drug resistance in mycobacterium tuberculosis: contribution of constituent and acquired mechanisms

RESUMEN En presencia de aislamientos de Mycobacterium tuberculosis (MTB) multifármaco-resistentes (MTB-MDR) y con resistencia extendida (MTB-XDR) las tasas de fracaso de los esquemas estandarizados de tratamiento son altas, constituyéndose en un verdadero problema de salud pública a nivel mundial. La fármaco-resistencia en MTB se debe principalmente a mutaciones en genes blanco; sin embargo, una proporción de aislamientos fármaco-resistentes no presentan mutaciones en dichos genes, sugiriendo la participación de otros mecanismos, tales como permeabilidad reducida de la pared celular, modificación enzimática y/o bombas de eflujo. La resistencia clínica a los medicamentos anti-tuberculosos (anti-TB) ocurre en gran parte como resultado de la selección de mutantes resistentes durante la falta de adherencia del paciente al tratamiento, inapropiados seguimientos y prescripción médica, dosis subóptimas de fármacos y dificultad de acceso a los servicios de salud y al tratamiento. Los Avances de la biología molecular y la secuenciación del genoma de MTB han contribuido a mejorar el entendimiento de los mecanismos de resistencia a los principales medicamentos anti-TB. Un mejor conocimiento de los mecanismos de fármaco-resistencia en MTB contribuirá a la identificación de nuevos blancos terapéuticos, al diseño de nuevos medicamentos, al desarrollo de nuevos métodos diagnósticos y/o mejorar las técnicas que actualmente están disponibles para la detección rápida de TB fármaco-resistente. Este artículo presenta una revisión actualizada de los mecanismos y las bases moleculares de la resistencia de MTB a medicamentos anti-TB.(AU)

ABSTRACT Due to the emergence of multi-drug resistant (MDR-MTB) and extensively drug-resistant (XDR-MTB) Mycobacterium tuberculosis (MTB) isolates, the failure rates of standard treatment regimens are high, thus becoming a major public health challenge worldwide. Resistance to anti-tuberculous (anti-TB) drugs is attributed mainly to specific mutations in target genes; however, a proportion of drug-resistant MTB isolates do not have mutations in these genes, which suggests the involvement of other mechanisms, such as the low permeability of the mycobacterial cell wall, enzymatic modification and/or efflux pumps. Clinical drug resistance to anti-TB drugs occurs largely as a result of the selection of resistant mutants caused by poor patient adherence to treatment, inappropriate follow-ups and prescriptions, suboptimal doses of drugs and poor access to health services and treatment. Major advances in molecular biology tools and the availability of the complete genome sequences of MTB have contributed to improve understanding of the mechanisms of resistance to the main anti-TB drugs. Better knowledge of the drug-resistance of MTB will contribute to the identification of new therapeutic targets to design new drugs, develop new diagnostic tests and/or improve methods currently available for the rapid detection of drug-resistant TB. This article presents an updated review of the mechanisms and molecular basis of drug resistance in MTB.(AU)

Epoetin alfa resistance in hemodialysis patients with chronic kidney disease: a longitudinal study

Anemia is an inevitable complication of hemodialysis, and the primary cause is erythropoietin deficiency. After diagnosis, treatment begins with an erythropoiesis-stimulating agent (ESA). However, some patients remain anemic even after receiving this medication. This study aimed to investigate the factors associated with resistance to recombinant human erythropoietin therapy with epoetin alfa (αEPO). We performed a prospective, longitudinal study of hemodialysis patients receiving treatment with αEPO at our reference hospital from July 2015 to June 2016. Clinical data was collected, and the response to αEPO treatment was evaluated using the erythropoietin resistance index (ERI). The ERI was defined as the weekly weight-adjusted αEPO dose (U/kg per week)/hemoglobin level (g/dL). A longitudinal linear regression model was fitted with random effects to verify the relationships between clinical and laboratory data and ERI. We enrolled 99 patients (average age, 45.7 (±17.6) years; male, 51.5%; 86.8% with hypertension). The ERI showed a significant positive association with serum ferritin and C-reactive protein, percentage interdialytic weight gain, and continuous usage of angiotensin receptor blocker (ARB) hypertension medication. The ERI was negatively associated with serum iron and albumin, age, urea reduction ratio, and body mass index. Our findings indicate that resistance to αEPO was related to a low serum iron reserve, an inflammatory state, poor nutritional status, and continuous usage of ARBs.

Informe final: encuesta de resistencia del VIH a los medicamentos antirretrovirales, Guatemala 2015-2016 / Final report: survey of HIV resistance to antiretroviral drugs, Guatemala 2015-2016

Informe que presenta los resultados de las encuestas realizadas según las recomendaciones de la OMS, para la vigilancia de resistencia pretratamiento y resistencia adquirida del VIH.

Seguridad y eficacia de paricalcitol en comparación a otros medicamentos en el tratamiento del hiperparatiroidismo secundario en pacientes con enfermedad renal estadío 5 en tratamiento sustitutivo con hemodiálisis o diálisis peritoneal y resistentes a calcitriol / Safety and efficacy of paricalcitol compared to other drugs in the treatment of secondary hyperparathyroidism in patients with stage 5 renal disease undergoing replacement therapy with hemodialysis or peritoneal dialysis and resistant to calcitriol

INTRODUCCIÓN: Antecedentes: El presente informe expone la evaluación del medicamento paricalcitol endovenoso (e.v) y oral, respecto a su uso en pacientes con hiperparatiroidismo secundario a enfermedad renal crónica (ERC) estadío 5 en tratamiento sustitutivo con hemodiálisis o diálisis peritoneal, y resistentes al tratamiento con calcitriol. Aspcetos Generales: El tratamiento del hiprparatiroidismo secundario (HPTs) en la enfermedad rnal crónica se base en el entendimiento de la patogénesis y la clínica de esta condición, y del reconocimiento que la homeostasis aormal del calcio y del fosforo puede incrementar la morbimortalidad. La insuficiencia renal se acompña de una disminución de la absorción del calcio de la excreción de fosfatos. Tecnología Sanitaria de Interés: Paracicalcitol: La reducción de la conversión de la vitamina D a su principal metabolito activo (1,25-hidroxivitamina D) en la Insuficiencia renal conduce a una reducción de la activación del receptor de la vitamina D (VDR), lo cual remueve la supresión inibitoria de la liberación de la hormona paratiroidea (PTH); el incremento sérico de PTH reduce la excreción de calcio e incrementa la resorción del hueso. Paricalcitol es un análogo sintético d ela vitamina D el cual se une y activa al VDR en el riñon, en la glándula paratiroidea, en el intestino y en el hueso; reduciendo así los niveles de PTH y mejorando la momeostasis del calcio y fosforo. METODOLOGÍA: Estrategia de Búsqueda: Se realizó una búsqueda de la literatura con recpecto a la eficacia y seguridad de paricalcitol e.v. y oral para el tratamiento de HPTs en pacientes con enfermedad renal crónica en hemodiálisis o en diálisis peritoneal, y con resistencia al tratamiento con calcitriol, en las bases de datos de OVID MEDLINE y TRIPDATABASE. También se hizo una búsqueda adicional en la página de registro de ensayos clínicos www.clinicaltrials.gov, para poder identificar ensayos en desarrollo o que se hayan realizado y no estén publicados. Adicionalmente, se hizo una búsqueda dentro de la información generada por grupos que realizan revisiones sistemáticas, evaluación de tecnologías sanitarias y guías de práctica clínica, tales como The Cochrane Library, The National Institute for helath and Care Excellence (NICE) y The National Guideline of Clearinghouse. RESULTADOS: Se realizó la búsqueda bibliográfica y de evidencia científica para el sustento del uso de paricalcitol como tratamiento de pacientes con HPTs en hemodiálisis y resistentes al tratamiento con calcitriol. Se presenta la evidencia disponible en guías de práctica clínica, ensayos clínicos no aleatorizados y un estudio registrado en www.clinicalstrials.gov. CONCLUSIONES: En la presente evaluación de tecnología sanitaria no se ha encontrado evidencia que muestre ue el paricaclcitorl ofrezca benefícios para los pacientes en hemodiálisis y resistentes al tratamiento con calcitriol en términos de desenlaces clínicamente relevantes para el paciente establecidos en la pregunta PICO, como la mortalidad, la calidad de vida, hospitalizaciones, eventos cardiovasculares y fracturas. Sin embargo, se ha identificado evidencia aunque proveniente de escasos estudios y de baja calidad, que muestra que paricalcitol puede tener un efecto en reducir los niveles séricos de PTH. Los pacientes de interés en en esta evaluaciónya han sido manejados con calcitriol usando dosis máximas tolerables y por un tiempo determinado, no logrando controlar los niveles bioquímicos de PTH. La situación de no mantener los níveles de PTH dentro de rangos recomendados indicaria persistencia de un recambio óseo anormal asociado a la enfermedad de osteodistrofia renal, por lo que requieren ser manejados con otras opciones terapéuticas disponibles. El Instituto de Evaluación de Tecnoglogías en Salud e Investigación_IETSI, aprueba temporalmente el uso de paricalcitol endovenoso y oral para el tratamiento del HPTs en pacientes en hemodiálisis o en diálisis peritonral y resistentes al tratamiento con calcitriol. Dado que la evidencia que respalda este uso de paricalcitol es aún limitada, se establece que el efecto de paricalcitol se evaluará con los datos de los pacientes que hayan recibido paricalcitol por el lapso de un año para determinar el impacto de su uso en varios desenlaces inclyendo los intermedios como los clínicos. Esta inforamción será tomada en cuenta en la re-evaluación de este medicamento para efectos de un nuevo dictamen al terminar la vigencia del presente Dictamen Preliminar.

Treatment with dasatinib or nilotinib in chronic myeloid leukemia patients who failed to respond to two previously administered tyrosine kinase inhibitors - a single center experience

OBJECTIVE: To evaluate hematological, cytogenetic and molecular responses as well as the overall, progression-free and event-free survivals of chronic myeloid leukemia patients treated with a third tyrosine kinase inhibitor after failing to respond to imatinib and nilotinib/dasatinib. METHODS: Bone marrow karyotyping and real-time quantitative polymerase chain reaction were performed at baseline and at 3, 6, 12 and 18 months after the initiation of treatment with a third tyrosine kinase inhibitor. Hematologic, cytogenetic and molecular responses were defined according to the European LeukemiaNet recommendations. BCR-ABL1 mutations were analyzed by Sanger sequencing. RESULTS: We evaluated 25 chronic myeloid leukemia patients who had been previously treated with imatinib and a second tyrosine kinase inhibitor. Nine patients were switched to dasatinib, and 16 patients were switched to nilotinib as a third-line therapy. Of the chronic phase patients (n=18), 89% achieved a complete hematologic response, 13% achieved a complete cytogenetic response and 24% achieved a major molecular response. The following BCR-ABL1 mutations were detected in 6/14 (43%) chronic phase patients: E255V, Y253H, M244V, F317L (2) and F359V. M351T mutation was found in one patient in the accelerated phase of the disease. The five-year overall, progression-free and event-free survivals were 86, 54 and 22% (p<0.0001), respectively, for chronic phase patients and 66%, 66% and 0% (p<0.0001), respectively, for accelerated phase patients. All blast crisis patients died within 6 months of treatment. Fifty-six percent of the chronic phase patients lost their hematologic response within a median of 23 months. CONCLUSIONS: Although the responses achieved by the third tyrosine kinase inhibitor were not sustainable, a third tyrosine kinase inhibitor may be an option for improving patient status until a donor becomes available for transplant. Because the long-term outcome ...

Oral cyclosporine therapy for refractory severe vernal keratoconjunctivitis.

We report the success of oral cyclosporine therapy in a patient with severe vision-threatening vernal keratoconjunctivitis. A child presented with severe allergy which was not controlled with topical steroids, cyclosporine and mast cell stabilizers. Oral steroids were required repeatedly to suppress inflammation. Child showed a dramatic improvement and stabilization with oral cyclosporine therapy. Oral cyclosporine therapy can be tried in severe vision-threatening allergy refractory to conventional therapy.

Evaluación del transporte de glucosa, fármacos y del potencial de membrana como métodos pronósticos de quimioterapia en Leishmania spp / Evaluation of glucose transport, drugs and membrane potential as prognostic methods of chemotherapy in Leishmania spp

El fracaso terapéutico en leishmaniasis a menudo esta asociado a resistencia a los medicamentos por parte de los parásitos. Hasta ahora no se ha evaluado sistemáticamente si este fenotipo compromete u optimiza el metabolismo o la efectividad en leishmania, es decir, su competencia y adaptabilidad. Durante su ciclo de vida los parásitos deben ajustarse a condiciones de vida extremas, lo cual no es gratuito. Al presentarse conflictos que comprometen propiedades de leishmania esenciales para su supervivencia, surge un costo de adaptación. Sin embargo, tales compensaciones son el precio a pagar que garantizan la co-evolucion del binomio hospedero-parásito y el mantenimiento de la diversidad genética de leishmania. Comprender ese costo es imprescindible a fin de diseñar medidas de prognosis y control exitosas. Adicionalmente, el método vigente y confiable para evaluar resistencia en leishmania es el método in vitro macrofago-amastigote, el cual es oneroso y laborioso. Como parte de un proyecto sobre quimo-resistencia en Leismania, planteamos evaluar posibles parámetros bioquímicos que pudieran servir como marcadores celulares a ser usados para identificar parásitos con fenotipo quimioresistentes en aislados de pacientes y compararlos con cepas de referencia. Los resultados sugieren que algunos aislados:a) tienen incrementada la expresión transportadores ABC, b) utilizan glucosa de forma diferencial, c) tienen un potencial de membrana menos polarizado y d) expresan diferente sensibilidad a inhibidores clásicos de la función mitocondrial. En conjunto, los datos indican que los aislados estudiados expresan los mismos cambios fisiológicos ya descritos en parásitos de referencia quimioresistentes. Es decir, que los cambios explorados podrían constituir un patrón general asociado a este fenómeno leishmania, lo cual los valida como marcadores celulares de resistencia. En conclusion, se propone un nuevo enfoque al problema del tratamiento de la enfermedad ya que, además de las estrategias clásicas, se añadirían herramientas de pronostico del éxito de la quimioterapia.

Late onset isotretinoin resistant acne conglobata in a patient with acromegaly.

A 55 year-old male presented with multiple pus-discharging abscesses and sinuses and mutilating scarring on the gluteal region and back prevalent for the last ten years with exacerbations and remissions. Physical examination revealed acromegaly with frontal bossing, prognathism, a barrel chest and acral hypertrophy. Dermatological examination revealed cutis verticis gyrata, thick eyelids, a large triangular nose, a thickened lower lip, macroglossia, widely spaced teeth and widened skin pores with wet and oily skin. Hair was fine and nails were flat and wide. There were multiple inflammatory papules, tender nodules, draining sinuses, and grouped, polyporous comedones as well as multiple and extensive depressed and keloidal scars localized predominantly over the gluteal region with a few scattered lesions over the back. A computed tomography (CT) scan showed widened sella turcica. His basal fasting growth hormone (GH) levels were markedly raised (230 ng/mL; normal 1-5 ng/mL) while the prolactin levels were moderately raised (87 ng/mL; normal 2-5 ng/mL). These findings were consistent with a diagnosis of acromegaly. The patient was put on antibiotics, nonsteroidal antiinflammatory drugs and isotretinoin at a dose of 1 mg/kg/day, which was increased to 1.5 mg/kg/day. Except for an initial mildly beneficial response, the skin lesions were largely resistant to high doses of isotretinoin at the end of four months.