Aspectos relacionados com a positividade para a esquistossomose: estudo transversal em área de baixa prevalência em Alagoas, 2020 / Aspectos relacionados con la positividad para la esquistosomiasis: un estudio transversal en un área de baja prevalencia en Alagoas, Brasil, 2020 / Aspects related to positivity for schistosomiasis: a cross-sectional study in a low prevalence area in Alagoas, Brazil, 2020

Objetivo: Analisar aspectos relacionados com a positividade para esquistossomose em área de baixa prevalência, no Brasil. Métodos: Estudo transversal, realizado no primeiro semestre de 2020, quando foram analisadas a proporção de positividade, em função do número de lâminas de Kato-Katz, o desempenho diagnóstico do teste e a estimação da positividade a partir dos dados do Sistema de Informação do Programa de Vigilância e Controle da Esquistossomose (SISPCE). Resultados: Foram analisadas 2.088 lâminas de 348 indivíduos, sendo a proporção de positividade de 11,8%, 26,7% e 31,0% para 1, 4 e 6 lâminas analisadas, respectivamente. Houve concordância excelente (índice Kappa = 0,91) na comparação entre as leituras de 4 e 6 lâminas. Foi estimada subnotificação de 2,1 vezes nos dados do SISPCE. Conclusão: Ampliar o número de lâminas aumentou a positividade do Kato-Katz, o que pode contribuir para maximizar o controle da doença enquanto problema de Saúde Pública.

Objetivo: Analizar aspectos relacionados con la positividad para esquistosomiasis en área de baja prevalencia en Brasil. Métodos: Estudio transversal, realizado en el primer semestre de 2020, donde se analizó la proporción de positividad según el número de portaobjetos de Kato-Katz, el rendimiento diagnóstico de la prueba y la creación de un factor de estimación de positividad a partir de los datos del Sistema de Información del Programa de Vigilancia y Control de la Esquistosomiasis (SISPCE). Resultados: Se analizaron 2.088 láminas de 348 individuos, con proporción de positividad del 11,8%, 26,7% y 31,0% para 1, 4 y 6 láminas analizadas, respectivamente. Hubo una excelente concordancia (Kappa = 0,91) en la comparación entre la lectura de 4 y 6 láminas. Se estimó un subregistro de 2,1 veces en los datos del SISPCE. Conclusión: Aumentar el número de muestras aumentó la positividad de Kato-Katz, lo que puede contribuir a maximizar el control de la enfermedad como problema de Salud Pública.

Objective: To analyze aspects related to schistosomiasis positivity in an area of low prevalence in Brazil. Methods: This was a cross-sectional study, carried out in the first half of 2020, where we analyzed the proportion of positivity, according to the number of Kato-Katz slides, the diagnostic performance of the test and positivity estimates based on data from the Schistosomiasis Surveillance and Control Program Information System (SISPCE). Results: 2,088 slides from 348 individuals were analyzed, with proportion of positivity of 11.8%, 26.7% and 31.0% for 1, 4 and 6 slides analyzed, respectively. There was excellent agreement (Kappa = 0.91) between the readings of 4 and 6 slides. The SISPCE data was estimated to be underreported by up to 2.1 times. Conclusion: Increasing the number of slides increased Kato-Katz positivity, which can contribute to maximizing the control of the disease as a Public Health problem.

Modification of the Alere GIARDIA Ag TEST immunochromatography KIT methodology for its use in frozen fecal sediment of dogs and cats

ABSTRACT Giardia duodenalis is a worldwide intestinal parasite and is one of the most frequent protozoa species infecting dogs and cats. This study aimed to modify the methodology of Alere GIARDIA Ag TEST KIT for its use in frozen fecal sediments with different storage times in a freezer (-20°C), thus expanding the range of use of this methodology. One hundred fecal sediments from dogs (n=50) and cats (n=50) previously examined by optical microscopy for Giardia cysts were selected for this study. The agreement between the modified immunochromatography and microscopy results was calculated by Kappa coefficient. To evaluate the performance of the modified immunochromatography assay on samples with different storage time, the fecal sediments were divided into three groups according to the time of storage in a freezer: (a) ≤ 1 year (n=37); (b) > 1 year and ≤ 3 years (n=39); (c) > 10 years (max. 13 years) (n=24). The results obtained by the modified immunochromatography assay demonstrates a higher sensitivity of this technique when compared with microscopy, regardless of the frozen storage time. These results allow for the use of this methodology in a greater scope of analysis, especially in frozen fecal sediment triage in sample collections, enabling epidemiological and comparative analysis along different decades.

Perfil químico y actividad antibacterial de los extractos de Peltigera laciniata (Merrill ex Riddle) Gyeln / Chemical profile and antibacterial activity of extracts from Peltigera laciniata (Merrill ex Riddle) Gyeln

Introducción: los líquenes, al presentar metabolitos secundarios como xantonas, antraquinonas y alcaloides, se han postulado como material con alto potencial biológico (e. g. antibiótico y antiviral), siendo el antibacterial muy promisorio, el cual se determina por medio de antibiogramas por difusión, punto central de esta investigación. Objetivo: evaluar la actividad antibacterial de los extractos de Peltigera laciniata (Merrill ex Riddle) Gyeln. Olmo de hoja cortada. Métodos: el material liquénico se sometió a percolación con etanol 96 por ciento. Al extracto crudo etanólico se le realizó el aislamiento de alcaloides totales y flavonoides totales con adición de HCL 3 por ciento y metanol, respectivamente. Ambas fracciones, fueron monitoreados por cromatografía de capa fina y fraccionados utilizando cromatografía de columna. Los extractos y fracciones se sometieron a bioensayos sobre Escherichia coli y Staphylococcus aureus para la valoración de los halos de inhibición, utilizando como control Sultamicilina. Los ensayos fueron realizados tres veces con 2 réplicas. Resultados: al realizar la separación cromatográfica de los alcaloides, se observó aumento de la inhibición en comparación con la mezcla alcaloidal. La fracción A1 presenta valores de inhibición cercanos al control y presentó los menores valores de inhibición con respecto a los demás tratamientos evaluados. El efecto de la fracción de los flavonoides totales tuvo menor impacto sobre E. coli y S. aureus, sin embargo, es importante destacar la acción antibacterial de los compuestos nitrogenados de tipo alcaloidal sobre microoganismos Gram positivos. Conclusiones: en el perfil químico realizado a partir de los extractos de la especie de estudio se visualizó la presencia de metabolitos secundarios de tipo alcaloide y flavonoide, evidenciando el efecto antimicrobiano de los alcaloides presentes en el extracto y la fracción, lo cual ratifica el potencial farmacológico de tipo antibacterial, atribuido al núcleo Protoberberínico(AU)

Introduction: Due to their content of secondary metabolites such as xanthones, anthraquinones and alkaloids, lichens have been suggested to be a material of high biological potential (e.g. antibiotic and antiviral). Their very promising antibacterial potential may be determined by diffusion antibiograms, the main concern of the present study. Objective: Evaluate the antibacterial activity of extracts obtained from Peltigera laciniata (Merrill ex Riddle) Gyeln, cutleaf elm. Methods: The lichenic material was percolated with 96 percent ethanol. Total alkaloids and total flavonoids were isolated from the crude ethanolic extract by adding 3 percent HCL and methanol, respectively. Both fractions were monitored by thin-layer chromatography and fractioned by column chromatography. Extracts and fractions were subjected to bioassays against Escherichia coli and Staphylococcus aureus for inhibition haloes, using sultamicillin as control. The assays were conducted 3 times with 2 replications. Results: Upon chromatographic separation of the alkaloids, an increase was observed in inhibition when compared with the alkaloidal mixture. Fraction A1 displayed inhibition values close to the control. Fraction FT showed lower inhibition values than the other treatments evaluated. The fraction of total flavonoids had a lesser impact on E. coli and S. aureus, but alkaloidal nitrogenated compounds had significant antibacterial activity against Gram-positive microorganisms. Conclusions: The chemical profile of extracts from the study species revealed the presence of alkaloidal and flavonoidal secondary metabolites, as well as the antimicrobial effect of the alkaloids contained in the extract and the fraction. This confirms the antibacterial pharmacological potential attributed to the protoberberine core(AU)

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Artemisinin is the active antimalarial compound obtained from the leaves of Artemisia annua L. Artemisinin, and its semi-synthetic derivatives, are the main drugs used to treat multi-drug-resistant Plasmodium falciparum (one of the human malaria parasite species). The in vitro susceptibility of P. falciparum K1 and 3d7 strains and field isolates from the state of Amazonas, Brazil, to A. annua infusions (5 g dry leaves in 1 L of boiling water) and the drug standards chloroquine, quinine and artemisinin were evaluated. The A. annua used was cultivated in three Amazon ecosystems (várzea, terra preta de índio and terra firme) and in the city of Paulínia, state of São Paulo, Brazil. Artemisinin levels in the A. annua leaves used were 0.90-1.13% (m/m). The concentration of artemisinin in the infusions was 40-46 mg/L. Field P. falciparum isolates were resistant to chloroquine and sensitive to quinine and artemisinin. The average 50% inhibition concentration values for A. annua infusions against field isolates were 0.11-0.14 μL/mL (these infusions exhibited artemisinin concentrations of 4.7-5.6 ng/mL) and were active in vitro against P. falciparum due to their artemisinin concentration. No synergistic effect was observed for artemisinin in the infusions.

Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals

The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study. The assays were performed in accordance with the Clinical and Laboratory Standards Institute guidelines and the combinations were tested using the checkerboard method. The minimum inhibitory concentrations were reduced by 11, 2.4, 4.3 and 3.5 times for amphotericin B, itraconazole, fluconazole and voriconazole, respectively. Moreover, it was seen that cotrimoxazole itself inhibited C. posadasii strains in vitro. The impairment of folic acid synthesis may be a potential antifungal target for C. posadasii.

Sentinel network for monitoring in vitro susceptibility of Plasmodium falciparum to antimalarial drugs in Colombia: a proof of concept

Drug resistance is one of the principal obstacles blocking worldwide malaria control. In Colombia, malaria remains a major public health concern and drug-resistant parasites have been reported. In vitro drug susceptibility assays are a useful tool for monitoring the emergence and spread of drug-resistant Plasmodium falciparum. The present study was conducted as a proof of concept for an antimalarial drug resistance surveillance network based on in vitro susceptibility testing in Colombia. Sentinel laboratories were set up in three malaria endemic areas. The enzyme linked immunosorbent assay-histidine rich protein 2 and schizont maturation methods were used to assess the susceptibility of fresh P. falciparum isolates to six antimalarial drugs. This study demonstrates that an antimalarial drug resistance surveillance network based on in vitro methods is feasible in the field with the participation of a research institute, local health institutions and universities. It could also serve as a model for a regional surveillance network. Preliminary susceptibility results showed widespread chloroquine resistance, which was consistent with previous reports for the Pacific region. However, high susceptibility to dihydroartemisinin and lumefantrine compounds, currently used for treatment in the country, was also reported. The implementation process identified critical points and opportunities for the improvement of network sustainability strategies.

Comparison of in vitro activity of five antifungal agents against dermatophytes, using the agar dilution and broth microdilution methods / Comparação da atividade in vitro de cinco agentes antifúngicos para dermatófitos, usando os métodos de diluição em ágar e microdiluição em caldo

The purpose of this study was to compare the agar dilution and broth microdilution methods for determining the minimum inhibitory concentration (MIC) of fluconazole, itraconazole, ketoconazole, griseofulvin and terbinafine for 60 dermatophyte samples belonging to the species Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. The percentage agreement between the two methods, for all the isolates with < 2 dilutions that were tested was 91.6 percent for ketoconazole and griseofulvin, 88.3 percent for itraconazole, 81.6 percent for terbinafine and 73.3 percent for fluconazole. One hundred percent agreement was obtained for Trichophyton mentagrophytes isolates evaluated with ketoconazole and griseofulvin. Thus, until a reference method for testing the in vitro susceptibility of dermatophytes is standardized, the similarity of the results between the two methods means that the agar dilution method may be useful for susceptibility testing on these filamentous fungi.

O propósito do presente trabalho foi comparar os métodos de diluição em ágar e diluição em caldo para a determinação de concentração inibitória mínima de fluconazol, itraconazol, cetoconazol, griseofulvina e terbinafina para 60 amostras de dermatófitos pertencentes às espécies, Trichophyton rubrum, Trichophyton. mentagrophytes e Microsporum canis. A porcentagem de acordo entre os dois métodos para todos os isolados testados considerando-se valores < 2 diluições, foram de 91,6 por cento para cetoconazol e para griseofulvina, de 88,3 por cento para itraconazol, de 81,6 por cento para terbinafina e de 73,3 por cento para fluconazol. Uma concordância de 100 por cento foi obtido para isolados de Trichophyton mentagrophytes avaliados com cetoconazol e griseofulvina. Desta forma, até que um método de referência seja padronizado para testar a suscetibilidade in vitro para os dermatófitos, os resultados semelhantes encontrados para os dois métodos fazem com que o método de diluição em ágar possa ser útil no teste de suscetibilidade para estes fungos filamentosos.

Drug Resistance and in Vitro Susceptibility of Plasmodium falciparum in Thailand during 1988-2003

The aim of the present study was to investigate antimalarial drug pressure resulting from the clinical use of different antimalarials in Thailand. The phenotypic diversity of the susceptibility profiles of antimalarials, i.e., chloroquine (CQ), quinine (QN), mefloquine (MQ), and artesunate (ARS) in Plasmodium falciparum isolates collected during the period from 1988 to 2003 were studied. P. falciparum isolates from infected patients were collected from the Thai-Cambodian border area at different time periods (1988-1989, 1991-1992, and 2003), during which 3 different patterns of drug use had been implemented: MQ + sulphadoxine (S) + pyrimethamine (P), MQ alone and MQ + ARS, respectively. The in vitro drug susceptibilities were investigated using a method based on the incorporation of [3H] hypoxanthine. A total of 50 isolates were tested for susceptibilities to CQ, QN, MQ, and ARS. Of these isolates, 19, 16, and 15 were adapted during the periods 1988-1989, 1991-1993, and 2003, respectively. P. falciparum isolates collected during the 3 periods were resistant to CQ. Sensitivities to MQ declined from 1988 to 2003. In contrast, the parasite was sensitive to QN, and similar sensitivity profile patterns were observed during the 3 time periods. There was a significantly positive but weak correlation between the IC50 values of CQ and QN, as well as between the IC50 values of QN and MQ. Drug pressure has impact on sensitivity of P. falciparum to MQ. A combination therapy of MQ and ARS is being applied to reduce the parasite resistance, and also increasing the efficacy of the drug.

Susceptibility of Colombian Plasmodium falciparum isolates to 4-aminoquinolines and the definition of amodiaquine resistance in vitro

There are wide variations in the threshold used to define in vitro resistance of Plasmodium falciparum to amodiaquine (AQ), probably due to differences in methodology and interpretation. In vitro susceptibility data of Colombian P. falciparum strains to AQ and N-desethylamodiaquine is used to illustrate the need to standardized methodologies and compare inhibitory concentrations, instead of resistant/susceptible phenotypes, when studying the mechanisms of resistance to AQ and monitoring drug susceptibility trends in the field.

Comparison of two in vitro sensitivity tests for Plasmodium falciparum.

The main purpose of the study was to compare the in vitro sensitivity results obtained from the two widely-used in vitro systems: (1) standard WHO micro-technique based on schizont maturation inhibition using fresh isolates (M-I), and (2) micro-technique based on incorporation of [3H]-hypoxanthine using culture-adapted isolates (M-II). The study was conducted during 1998 and 2002. A total of 473 Plasmodium falciparum isolates were collected from five highly malaria endemic areas of Thailand, ie, Mae Sot district, Tak (north-western), Kanchanaburi (western), Ranong (south-western), Ratchaburi (south-western) and Chantaburi (eastern) Provinces. The antimalarials tested were: mefloquine, quinine, chloroquine, artemisinin and dihydroartemisinin. The sensitivity results for mefloquine obtained from the two methods were significantly different from each other. The IC50 values for M-II was less than M-I. The median (95%C.I.) IC50 value for mefloquine using the M-II method was significantly lower [696.47 (393.11-1,233.2) nM] than for M-I [3,955.4 (1,035.61-5,108.9) nM]. The in vitro sensitivity results for quinine were significantly different from each other. The median (95% C.I.) IC50 value for M-II [161 (42-351) nM] was 2.5-fold that of M-I [66 (24-450) nM].