RESUMO
Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.
Assuntos
Antifúngicos/farmacologia , Candida glabrata/efeitos dos fármacos , Candida/efeitos dos fármacos , Colubrina/química , Flavonoides/farmacologia , Animais , Antifúngicos/química , Artemia/efeitos dos fármacos , Candida/isolamento & purificação , Chlorocebus aethiops , Farmacorresistência Fúngica/efeitos dos fármacos , Flavonoides/química , Flavonoides/isolamento & purificação , Fluconazol/farmacologia , Glicosilação , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Componentes Aéreos da Planta/química , Testes de Toxicidade , Células VeroRESUMO
Abstract The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p < 0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence.
Assuntos
Humanos , Masculino , Feminino , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus epidermidis/efeitos dos fármacos , Coagulase/sangue , Staphylococcus haemolyticus/efeitos dos fármacos , Linezolida/farmacologia , Antibacterianos/farmacologia , Valores de Referência , Staphylococcus epidermidis/genética , DNA Bacteriano , Testes de Sensibilidade Microbiana , Eletroforese em Gel de Campo Pulsado , Coagulase/isolamento & purificação , Coagulase/genética , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana , Staphylococcus haemolyticus/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase Multiplex , MéxicoRESUMO
The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p<0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence.
Assuntos
Antibacterianos/farmacologia , Coagulase/sangue , Linezolida/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus haemolyticus/efeitos dos fármacos , Staphylococcus haemolyticus/isolamento & purificação , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Coagulase/genética , Coagulase/isolamento & purificação , DNA Bacteriano , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , México , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase Multiplex , Valores de Referência , Staphylococcus epidermidis/genética , Staphylococcus haemolyticus/genéticaRESUMO
BACKGROUND: Candida infections have increased in the last few decades. Previous colonization is the most important risk factor for the development of fungemia. Understanding local epidemiology is necessary in order to select the optimal anti-fungal treatment. The purpose of this study was to establish colonization by Candida in patients, staff and medical devices in a neonatal intensive care unit. METHODS: A prospective cohort study was conducted. Cultures were obtained from different anatomic sites, from medical devices and from the hands of healthcare staff at admission and every 7 days until discharge of the unit. Identification and susceptibility tests to amphotericin B, fluconazole, itraconazole, voriconazole and caspofungin were performed. RESULTS: Out of 98 patients, 24 % were already colonized at admission, 15 % became colonized during their stay at the hospital. Out of 738 samples obtained from devices, 2 % were positive. Out of 89 cultures obtained from hands, 55 % were positive. A total of 124 Candida strains were retrieved; Candida parapsilosis was the most common species (59 %), followed by Candida albicans (26 %). Resistance to itraconazole was only found in 13 %. CONCLUSIONS: Colonization in neonatal intensive care-admitted patients was 40 %, and it was a common event in the hands of the healthcare staff. Candida parapsilosis was the predominant species. Resistance was found only to itraconazole.
INTRODUCCIÓN: las infecciones por Candida se han incrementado en las últimas décadas. La colonización previa es el principal factor de riesgo para el desarrollo de fungemia. Es necesario conocer la epidemiología local de un hospital para seleccionar el tratamiento óptimo. El objetivo del estudio que se presenta fue establecer la colonización por especies de Candida en pacientes, personal y dispositivos médicos en una unidad de cuidados intensivos neonatales. MÉTODOS: se llevó a cabo un estudio prospectivo de cohorte. Se obtuvieron muestras de diferentes sitios anatómicos, de dispositivos médicos y de manos del personal de salud, al ingreso de los pacientes y cada siete días hasta el egreso de la unidad. Se realizó identificación de los microorganismos y se determinó su sensibilidad a anfotericina B, fluconazol, itraconazol, voriconazol y caspofungina. RESULTADOS: de 98 pacientes, 24 % estaba colonizado al ingreso y 15 % se colonizó durante su estancia en la unidad. De 738 muestras de dispositivos, 2 % resultó positivo. De 89 cultivos de manos, 55 % fue positivo. Se recuperaron en total 124 cepas de Candida; la especie parapsilosis fue la especie más común (59 %), seguida de albicans (26 %). Solo se encontró resistencia a itraconazol en 13 %. CONCLUSIONES: se observó colonización en 40 % de los pacientes ingresados en la unidad de cuidados intensivos neonatales y en las manos del personal de salud fue frecuente. Predominó la especie Candida parapsilosis. Solo se encontró resistencia a itraconazol.
Assuntos
Candida/isolamento & purificação , Unidades de Terapia Intensiva Neonatal , Contaminação de Equipamentos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos ProspectivosRESUMO
The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL).
Assuntos
Anti-Infecciosos/análise , Antioxidantes/análise , Magnoliopsida/química , Óleos Voláteis/química , Anacardiaceae/química , Asteraceae/química , Frutas/química , Magnolia/química , México , Testes de Sensibilidade Microbiana , Folhas de Planta/químicaRESUMO
Molecular studies of the genome of the fungus Coccidioides have demonstrated two nearly identical, but well-identified species, Coccidioides immitis and C. posadasii, known as "California" and "non-California" species, respectively. The objective of this study was to determine, through molecular methods, whether both species of Coccidioides are present in Mexican patients with coccidioidomycosis and to estimate, their geographical distribution in Mexico. We analyzed 56 clinical isolates of Coccidioides spp. from Mexican patients. Molecular identification of each strain was done by means of real time PCR using TaqMan(R) probes to amplify single nucleotide polymorphisms (SNPs) in four target sequences, loci, named proline 157, proline 174, hexokinase 149 and glucose-synthase 192. SNP analysis identified two of the 56 isolates as Coccidioides immitis and the remaining 54 as C. posadasii. The dual probe assay that included proline 157, proline 174 and glucose-synthase 192 gave consistent results on SNP differentiation between the two species. In contrast, the template matching hexokinase 149 gave negative results for any species in 34 samples. Our results did not show geographical overlap of the species, and they also confirmed that C. posadasii is the most frequent species in Mexico. A vast majority of C. posadasii strains were localized in the north-central region of the country.