Rifampicin: biotransformation study using the fungus Cunninghamella elegans and monitoring through UHPLC-MS

Drug biotransformation studies appear as an alternative to pharmacological investigations of metabolites, development of new drug candidates with reduced investment and most efficient production. The objective of this study was to evaluate the capacity of biotransformation of Rifampicin (RIF) by the filamentous fungus Cunninghamella elegans as a microbial model of mammalian metabolism. In 120 h, C. elegans transformed the drug into the following two metabolites: rifampicin quinone and novel metabolite. The products of rifampicin formed in vitro were monitored by HPLC-PDA, being identified through UHPLC–QTOF/MS. Metabolites were characterized according to their chromatographic profile, mass fragments and UV spectral data. The major metabolic pathways of rifampicin transformed by the fungus were oxidation, demethylation and mono-oxidation. The microbial transformation of RIF showed the potential of Cunninghamella species to produce RIF metabolites. This process can be used for a cost effective method for both known and unknown metabolite production

Multidrug-resistant Candida glabrata strains obtained by induction of anidulafungin resistance in planktonic and biofilm cells

Candida glabrata has emerged as a common cause of serious life-threatening fungal infections, largely owing to their low susceptibility to azole antifungals. Recent guidance indicates the use of echinocandins as the first-choice drug for the treatment of systemic infections of C. glabrata; however, C. glabrata resistance to echinocandins is reportedly increasing. Herein, we present the induction of anidulafungin resistance in planktonic and sessile cells of C. glabrata and the development of fluconazole crossresistance. MICs of 21 clinical C. glabrata strains were determined by a broth microdilution method using anidulafungin and fluconazole. Biofilm formation on a tracheal catheter was determined using 1- × 1-cm2 polyvinyl polychloride catheter fragments. Induction of anidulafungin resistance in planktonic and sessile cells and evaluation of its stability were performed by exposing the strains to successively higher concentrations of the antifungal. The induction resulted in strains strongly resistant to anidulafungin (MICs: 1−2 μg/mL) and fluconazole (≥64 μg/mL). Most of the sessile cells of C. glabrata presented slightly reduced susceptibility compared with the planktonic cells. Clinically, this cross-resistance could lead to therapeutic failure while using fluconazole in patients previously exposed to subinhibitory concentrations of anidulafungin for extended periods

Antifungal activity of actinobacteria against fungus isolates of clinical importance

The escalating use of antifungal agents and long-term treatment approaches has led to an increased prevalence of fungus species that are resistant to the most common antifungal drugs. Actinobacteria produce a wide variety of bioactive secondary metabolites. This study investigated actinomycete isolates with the potential to produce bioactive compounds against dermatophyte fungus species and Candida spp. of clinical importance. Antifungal activity of actinomycetes was assessed using the double-layer agar technique. Active isolates were cultivated in starch casein broth (SCB) at 30 ºC for 8 days. Aliquots were retrieved at 24-h intervals and centrifuged to obtain extracts. Extract activity was assessed using the well-diffusion method. No dermatophyte fungus isolate was inhibited in the double-layer assay, although isolates 1S, R18(6) and 6(2) were active against all Candida spp. used in the assay. The well-diffusion method revealed that isolate R18(6) inhibited the six Candida spp. in a 72-h growth period in SCB broth, showing good potential to yield a compound with antifungal activity.(Atividade antifúngica de actinobactérias contra fungos isolados de importância clínica).O uso crescente de antifúngicos e os tratamentos prolongados vêm aumentando a incidência de fungos resistentes às drogas antifúngicas comumente utilizadas. As actinobactérias são conhecidas por produzirem uma grande variedade de metabólitos secundários bioativos e este trabalho teve como objetivo selecionar isolados de actinomicetos com potencial para produção de compostos bioativos contra fungos dermatófitos e espécies de Candida de importância clínica. A atividade antifúngica dos actinomicetos foi avaliada pela técnica da dupla camada. Os isolados que apresentaram atividade foram cultivados em caldo amido caseína (AC) à temperatura de 30 ºC por oito dias e foram retiradas e centrifugadas alíquotas a cada 24h, para obtenção do extrato. A atividade dos extratos foi avaliada através da técnica de difusão em poço. Nenhum dos isolados de fungos dermatófitos foi inibido no ensaio de dupla camada e os isolados 1S, R18(6) e 6(2) mostraram atividade frente todas as espécies de Candida testadas. No ensaio de difusão em poço com os extratos, o isolado R18(6) inibiu as seis espécies de Candida em 72h de crescimento em caldo AC e mostrou grande potencial para obtenção de composto com atividade antifúngica

New 99mTc-Labeled Digitoxigenin Derivative for Cancer Cell Identification

In recent years, cardiac glycosides (CGs) have been investigated as potential antiviral and anticancer drugs. Digitoxigenin (DIG) and other CGs have been shown to bind and inhibit Na+/K+-adenosinetriphosphatase (ATPase). Tumor cells show a higher expression rate of the Na+/K+-ATPase protein or a stronger affinity towards the binding of CGs and are therefore more prone to CGs than non-tumor cells. Cancer imaging techniques using radiotracers targeted at specific receptors have yielded successful results. Technetium-99m (99mTc) is one of the radionuclides of choice to radiolabel pharmaceuticals because of its favorable physical and chemical properties along with reasonable costs. Herein, we describe a new Na+/K+-ATPase targeting radiotracer consisting of digitoxigenin and diethylenetriaminepentaacetic acid (DTPA), a bifunctional chelating ligand used to prepare 99mTc-labeled complexes, and its evaluation as an imaging probe. We report the synthesis and characterization of the radiolabeled compound including stability tests, blood clearance, and biodistribution in healthy mice. Additionally, we investigated the binding of the compound to A549 human non-small-cell lung cancer cells and the inhibition of the Na+/K+-ATPase by the labeled compound in vitro. The 99mTc-labeled DTPA–digitoxigenin (99mTc-DTPA–DIG) compound displayed high stability in vitro and in vivo, a fast renal excretion, and a specific binding towards A549 cancer cells in comparison to non-tumor cells. Therefore, 99mTc-DTPA–DIG could potentially be used for non-invasive visualization of tumor lesions by means of scintigraphic imaging

Assessment of the genotoxic impact of pesticides on farming communities in the countryside of Santa Catarina State, Brazil

The aim of this study was to assess the use of pesticides on farms located in the Lambedor River watershed in Guatambu, State of Santa Catarina, as well as to determine, by micronucleus testing, the risk of genotoxic impact. Samples from locally collected Cyprinus carpio, Hypostomus punctatus, Rhamdia quelen and Oreochromis niloticus gave evidence of a mean increase in micronuclei frequency from 6.21 to 13.78 in 1,000 erythrocytes, a clear indication of the genotoxic potenciality of pesticide residues in regional dams, and their significant contribution to local environmental contamination

New 99mTc-labeled digitoxigenin derivative for cancer cell identification

In recent years, cardiac glycosides (CGs) have been investigated as potential antiviral and anticancer drugs. Digitoxigenin (DIG) and other CGs have been shown to bind and inhibit Na+ /K+ -adenosinetriphosphatase (ATPase). Tumor cells show a higher expression rate of the Na+ /K+ - ATPase protein or a stronger affinity towards the binding of CGs and are therefore more prone to CGs than non-tumor cells. Cancer imaging techniques using radiotracers targeted at specific receptors have yielded successful results. Technetium99m (99mTc) is one of the radionuclides of choice to radiolabel pharmaceuticals because of its favorable physical and chemical properties along with reasonable costs. Herein, we describe a new Na+ /K+ -ATPase targeting radiotracer consisting of digitoxigenin and diethylenetriaminepentaacetic acid (DTPA), a bifunctional chelating ligand used to prepare 99mTc-labeled complexes, and its evaluation as an imaging probe. We report the synthesis and characterization of the radiolabeled compound including stability tests, blood clearance, and biodistribution in healthy mice. Additionally, we investigated the binding of the compound to A549 human non-small-cell lung cancer cells and the inhibition of the Na+ /K+ - ATPase by the labeled compound in vitro. The 99mTc-labeled DTPA−digitoxigenin (99mTc-DTPA−DIG) compound displayed high stability in vitro and in vivo, a fast renal excretion, and a specific binding towards A549 cancer cells in comparison to nontumor cells. Therefore, 99mTc-DTPA−DIG could potentially be used for non-invasive visualization of tumor lesions by means of scintigraphic imaging

The influence of the microwave oven on the production of solid culture medium and quality of microbial growth

Abstract Numerous cultivation media currently exist, whether selective, non-selective, enrichment or identification. However, they all have a common goal, which is the growth of microorganisms; the constitution and quality of the culture medium must favor it. For this reason, an important factor that directly affects the quality of a culture medium is its production. Thus, this article investigated the use of a microwave oven in the production of Sabouraud dextrose agar (SDA), and the microbial inactivation compared to the autoclave in a microbiology laboratory. The quality of the medium, time exposure, and sterilization potential were performed using fungal strains of Candida spp., Cryptococcus spp., Microsporum spp., and Aspergillus spp. The results showed that the advantages of the use of a microwave oven for the preparation of SDA are practicality, speed, lower energy expense, pH, and constituents preservation of the culture medium, resulting in a richer growth compared to autoclaved SDA. The multivariate analysis of digital images allowed the detection of melanoidins (brownish tone of medium), which are responsible for the negative influence on the microorganisms growth. This research shows the use of the microwave oven as an efficient alternative for the production of the culture medium and maintaining their best quality

Tetanus epidemiology in Santa Catarina, Brazil from 1998 to 2008

AbstractObjetiveThis work describes demographic and clinical characteristics of individuals with accidental tetanus in Santa Catarina, Brazil.Materials and Methods291 cases of accidental tetanus reported from 1998 to 2008 were analyzed retrospectively through a cross-sectional, descriptive and correlated study based on percentage and numeric frequency as well as on number and incidence rate (i.r.) found in compulsory notification forms.ResultsMost cases (73,54%) occurred among men residing in Vale do Itajaí (30,24%). The age group with the highest incidence was within the 35 to 49 range (32,30%). Complete immunization history was reported in seven cases (2,40%), the perforating injury being the most observed and the lower limbs the most affected ones. Among the reported cases, 87,62% were confirmed; 114 (39,17%) patients died.ConclusionsAccidental tetanus in Santa Catarina affects the population in a significant way despite the fact that it is an immune preventable disease. The authorities and administrators must plan strategies to address changes in public policies related to immunization coverage of the susceptible population, mainly adults. Above all, it is important to warn society that the success of immunization programs depends on the application of three doses at set intervals, application of booster doses and compliance with the vaccination schedule

Tetanus epidemiology in Santa Catarina, Brazil from 1998 to 2008 Epidemiología del tétanos en Santa Catarina, Brasil, entre 1998 y 2008

Objetive: This work describes demographic and clinical characteristics of individuals with accidental tetanus in Santa Catarina, Brazil. Materials and Methods: 291 cases of accidental tetanus reported from 1998 to 2008 were analyzed retrospectively through a cross-sectional, descriptive and correlated study based on percentage and numeric frequency as well as on number and incidence rate (i.r.) found in compulsory notification forms. Results: Most cases (73,54%) occurred among men residing in Vale do Itajaí (30,24%). The age group with the highest incidence was within the 35 to 49 range (32,30%). Complete immunization history was reported in seven cases (2,40%), the perforating injury being the most observed and the lower limbs the most affected ones.Among the reported cases, 87,62% were confirmed; 114 (39,17%) patients died. Conclusions: Accidental tetanus in Santa Catarina affects the population in a significant way despite the fact that it is an immune preventable disease. The authorities and administrators must plan strategies to address changes in public policies related to immunization coverage of the susceptible population, mainly adults. Above all, it is important to warn society that the success of immunization programs depends on the application of three doses at set intervals, application of booster doses and compliance with the vaccination schedule.<br>Objetivo: El presente trabajo describe las características demográficas y clínicas de los individuos con tétanos accidental en Santa Catarina, Brasil. Materiales y métodos: se analizaron 291 casos de tétanos accidental reportados desde el año 1998 hasta 2008, a través de un estudio descriptivo tipo corte transversal. Con base en el porcentaje y frecuencia numérica, así como en la tasa de incidencia registrada según los formularios de notificación obligatoria. Resultados: La mayoría de los casos (73,54%) ocurrieron en los hombres que residen en Vale do Itajaí (30,24%). El grupo con mayor incidencia fue en el rango de edad de 35 a 49 años (32,30%). La historia completa de inmunización se informó en siete casos (2,40%), la lesión perforante fue la más observada, las extremidades inferiores fueron las más afectadas. Entre los casos reportados 87(62%) fueron confirmados; 114 (39,17%) pacientes murieron. Conclusiones: el tétanos accidental en Santa Catarina afecta a la población de manera significativa a pesar del hecho de que es una enfermedad prevenible. Las autoridades y los administradores deben planear estrategias para generar cambios en las políticas públicas relacionadas con la cobertura de inmunización de la población susceptible, sobre todo los adultos. Es importante advertir a la sociedad que el éxito de los programas de inmunización depende de la aplicación de tres dosis a intervalos establecidos, la aplicación de las dosis de refuerzo y el cumplimiento del calendario de vacunación

Antifungal activity of actinobacteria against fungus isolates of clinical importance

The escalating use of antifungal agents and long-term treatment approaches has led to an increased prevalence of fungus species that are resistant to the most common antifungal drugs. Actinobacteria produce a wide variety of bioactive secondary metabolites. This study investigated actinomycete isolates with the potential to produce bioactive compounds against dermatophyte fungus species and Candida spp. of clinical importance. Antifungal activity of actinomycetes was assessed using the double-layer agar technique. Active isolates were cultivated in starch casein broth (SCB) at 30 ºC for 8 days. Aliquots were retrieved at 24-h intervals and centrifuged to obtain extracts. Extract activity was assessed using the well-diffusion method. No dermatophyte fungus isolate was inhibited in the double-layer assay, although isolates 1S, R18(6) and 6(2) were active against all Candida spp. used in the assay. The well-diffusion method revealed that isolate R18(6) inhibited the six Candida spp. in a 72-h growth period in SCB broth, showing good potential to yield a compound with antifungal activity.(Atividade antifúngica de actinobactérias contra fungos isolados de importância clínica).O uso crescente de antifúngicos e os tratamentos prolongados vêm aumentando a incidência de fungos resistentes às drogas antifúngicas comumente utilizadas. As actinobactérias são conhecidas por produzirem uma grande variedade de metabólitos secundários bioativos e este trabalho teve como objetivo selecionar isolados de actinomicetos com potencial para produção de compostos bioativos contra fungos dermatófitos e espécies de Candida de importância clínica. A atividade antifúngica dos actinomicetos foi avaliada pela técnica da dupla camada. Os isolados que apresentaram atividade foram cultivados em caldo amido caseína (AC) à temperatura de 30 ºC por oito dias e foram retiradas e centrifugadas alíquotas a cada 24h, para obtenção do extrato. A atividade dos extratos foi avaliada através da técnica de difusão em poço. Nenhum dos isolados de fungos dermatófitos foi inibido no ensaio de dupla camada e os isolados 1S, R18(6) e 6(2) mostraram atividade frente todas as espécies de Candida testadas. No ensaio de difusão em poço com os extratos, o isolado R18(6) inibiu as seis espécies de Candida em 72h de crescimento em caldo AC e mostrou grande potencial para obtenção de composto com atividade antifúngica