RESUMEN

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.

Asunto(s)

Antifúngicos/farmacología , Candida glabrata/efectos de los fármacos , Candida/efectos de los fármacos , Colubrina/química , Flavonoides/farmacología , Animales , Antifúngicos/química , Artemia/efectos de los fármacos , Candida/aislamiento & purificación , Chlorocebus aethiops , Farmacorresistencia Fúngica/efectos de los fármacos , Flavonoides/química , Flavonoides/aislamiento & purificación , Fluconazol/farmacología , Glicosilación , Pruebas de Sensibilidad Microbiana , Fitoquímicos/química , Fitoquímicos/farmacología , Componentes Aéreos de las Plantas/química , Pruebas de Toxicidad , Células Vero

Asunto(s)

Dermatosis Facial/diagnóstico , Dermatosis Facial/microbiología , Tiña/diagnóstico , Tiña/terapia , Preescolar , Dermatosis Facial/terapia , Femenino , Humanos

RESUMEN

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.

Asunto(s)

Humanos , Masculino , Femenino , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus epidermidis/efectos de los fármacos , Coagulasa/sangre , Staphylococcus haemolyticus/efectos de los fármacos , Linezolid/farmacología , Antibacterianos/farmacología , Valores de Referencia , Staphylococcus epidermidis/genética , ADN Bacteriano , Pruebas de Sensibilidad Microbiana , Electroforesis en Gel de Campo Pulsado , Coagulasa/aislamiento & purificación , Coagulasa/genética , Biopelículas/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana , Staphylococcus haemolyticus/aislamiento & purificación , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Tipificación de Secuencias Multilocus , Reacción en Cadena de la Polimerasa Multiplex , México

RESUMEN

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.

Asunto(s)

Antibacterianos/farmacología , Coagulasa/sangre , Linezolid/farmacología , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/aislamiento & purificación , Staphylococcus haemolyticus/efectos de los fármacos , Staphylococcus haemolyticus/aislamiento & purificación , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Coagulasa/genética , Coagulasa/aislamiento & purificación , ADN Bacteriano , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , México , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Reacción en Cadena de la Polimerasa Multiplex , Valores de Referencia , Staphylococcus epidermidis/genética , Staphylococcus haemolyticus/genética

RESUMEN

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.

Asunto(s)

Candida/aislamiento & purificación , Unidades de Cuidado Intensivo Neonatal , Contaminación de Equipos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos

RESUMEN

Seven 3-month-old, female, helminth-free lambs were immunized intranasally with three doses (1 mg total) of a recombinant part of the catalytic region of the serine/threonine phosphatase 2A (PP2Ar) (group 1 [G1]). In addition, four lambs were used as an adjuvant control group (G2), four as unimmunized, infected controls (G3), and four as unimmunized, uninfected controls (G4). Fifteen days after the last immunization, lambs from G1, G2, and G3 were challenged with 10,000 larval stage 3 (L3) organisms in a plurispecific nematode infection composed of ca. 40% Trichostrongylus colubriformis, 40% Haemonchus contortus, and 20% Teladorsagia circumcincta. All the lambs were clinically monitored throughout the experiment. Parasitological (fecal egg output and immunological response), biopathological (packed-cell volume and leukocyte and eosinophil counts), and zootechnical (live-weight gain) analyses were conducted. On day 105 of the experiment, all the animals were slaughtered and the adult worm population in their abomasa examined. Intranasal administration of PP2Ar with bacterial walls as an adjuvant elicited a strong immune response in the immunized lambs, as evidenced by their humoral immune response. Immunized animals and animals receiving the adjuvant shed significantly (P < 0.001) fewer numbers of parasites' eggs in their feces. The immunization significantly reduced the helminth burden in the abomasa by the end of the experiment (>68%), protection being provided against both Haemonchus and Teladorsagia. Live-weight gain in the immunized lambs was similar to that in the uninfected controls versus the infected or adjuvanted animal groups. Our results suggest that heterologous immunization of ruminants by intranasal administration may be efficacious in the struggle to control gastrointestinal helminths in these livestock.

Asunto(s)

Antígenos Helmínticos/inmunología , Enfermedades Intestinales/veterinaria , Nematodos/enzimología , Nematodos/inmunología , Infecciones por Nematodos/veterinaria , Proteína Fosfatasa 2/inmunología , Vacunación/métodos , Adyuvantes Inmunológicos/administración & dosificación , Administración Intranasal , Animales , Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/administración & dosificación , Antígenos Helmínticos/genética , Bacterias/química , Peso Corporal , Pared Celular/metabolismo , Heces/parasitología , Femenino , Helmintiasis/prevención & control , Enfermedades Intestinales/prevención & control , Parasitosis Intestinales , Nematodos/genética , Infecciones por Nematodos/prevención & control , Recuento de Huevos de Parásitos , Proteína Fosfatasa 2/administración & dosificación , Proteína Fosfatasa 2/genética , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Ovinos

RESUMEN

BACKGROUND: Among Coagulase-Negative Staphylococci (CoNS), Staphylococcus hominis represents the third most common organism recoverable from the blood of immunocompromised patients. The aim of this study was to characterize biofilm formation, antibiotic resistance, define the SCCmec (Staphylococcal Chromosomal Cassette mec) type, and genetic relatedness of clinical S. hominis isolates. METHODOLOGY: S. hominis blood isolates (n = 21) were screened for biofilm formation using crystal violet staining. Methicillin resistance was evaluated using the cefoxitin disk test and the mecA gene was detected by PCR. Antibiotic resistance was determined by the broth microdilution method. Genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE) and SCCmec typed by multiplex PCR using two different methodologies described for Staphylococcus aureus. RESULTS: Of the S. hominis isolates screened, 47.6% (10/21) were categorized as strong biofilm producers and 23.8% (5/21) as weak producers. Furthermore, 81% (17/21) of the isolates were methicillin resistant and mecA gene carriers. Resistance to ampicillin, erythromycin, and trimethoprim was observed in >70% of isolates screened. Each isolate showed a different PFGE macrorestriction pattern with similarity ranging between 0-95%. Among mecA-positive isolates, 14 (82%) harbored a non-typeable SCCmec type: eight isolates were not positive for any ccr complex; four contained the mec complex A ccrAB1 and ccrC, one isolate contained mec complex A, ccrAB4 and ccrC, and one isolate contained the mec complex A, ccrAB1, ccrAB4, and ccrC. Two isolates harbored the association: mec complex A and ccrAB1. Only one strain was typeable as SCCmec III. CONCLUSIONS: The S. hominis isolates analyzed were variable biofilm producers had a high prevalence of methicillin resistance and resistance to other antibiotics, and high genetic diversity. The results of this study strongly suggested that S. hominis isolates harbor new SCCmec structural elements and might be reservoirs of ccrC1 in addition to ccrAB1 and mec complex A.

Asunto(s)

Antibacterianos/farmacología , Proteínas Bacterianas/genética , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple , Staphylococcus hominis/efectos de los fármacos , Staphylococcus hominis/genética , Proteínas Bacterianas/metabolismo , Técnicas de Tipificación Bacteriana , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , ADN Bacteriano/clasificación , Variación Genética , Humanos , Resistencia a la Meticilina , Pruebas de Sensibilidad Microbiana , Filogenia , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus hominis/clasificación , Staphylococcus hominis/aislamiento & purificación

RESUMEN

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).

Asunto(s)

Antiinfecciosos/análisis , Antioxidantes/análisis , Magnoliopsida/química , Aceites Volátiles/química , Anacardiaceae/química , Asteraceae/química , Frutas/química , Magnolia/química , México , Pruebas de Sensibilidad Microbiana , Hojas de la Planta/química

RESUMEN

BACKGROUND: Immunostimulating complexes (ISCOM)-type nanocapsules have been functionalized with lipid vinyl sulfones that anchor to them via the hydrophobic zone of their structure and can be charged with pharmacologically active molecules or macromolecules. These functionalized nanocapsules can incorporate protein A and bind to G immunoglobulins (IgGs) to make vehicles directed at the surface antigens of infectious agents, tumor cells, or receptor cells and deliver the encapsulated molecules in a highly specific way. They may be of particular use in pharmacological treatments with highly toxic molecules that should not be used in solution whenever it can be avoided. When bound to antibodies they can be used in biological processes that require the delivery or presentation of macromolecules to certain specific cells, in immunization processes for instance, or in diagnostic immunological techniques, as they are able to transport both the secondary antibodies and the reaction labels. METHODS AND RESULTS: We describe the preparation of ISCOMs, the binding to the ISCOMS of newly synthesized compounds composed of chain alkyl vinyl sulfone, and the subsequent binding of the vinyl-sulfone compounds to IgGs. Within this context, a compound deriving from cholesterol functionalized with vinyl sulfone and used together with cholesterol in varying proportions has been linked to the structure of the ISCOMs and bound to protein A-IgG. This functionalization in no way altered the form or structure of the ISCOMs and allowed the nanocapsules carrying the specific IgGs to bind to forms of Trypanosoma cruzi against which antibodies had been developed. The fact that functionalized ISCOMs containing antibodies could deliver actinomycin D directly to the parasite meant that the effective dose of the antibiotic could be reduced very significantly. CONCLUSION: We have developed ISCOM-type nanocapsules functionalized with lipid vinyl sulfone capable of anchoring to the surface of functional IgGs, which favors the recognition and transport of these nanocapsules precisely to certain kinds of cell.

Asunto(s)

ISCOMs/administración & dosificación , ISCOMs/inmunología , Inmunoglobulina G/inmunología , Inmunoterapia/métodos , Lípidos/química , Nanocápsulas/química , Sulfonas/química , Composición de Medicamentos/métodos , Nanocápsulas/ultraestructura

RESUMEN

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.

Asunto(s)

Química Clínica/métodos , Coccidioides/genética , Coccidioides/metabolismo , Coccidioidomicosis/diagnóstico , Coccidioidomicosis/metabolismo , Técnicas Microbiológicas , Técnicas de Tipificación Micológica , Cartilla de ADN/genética , ADN de Hongos/genética , Geografía , Humanos , México , Polimorfismo de Nucleótido Simple , Especificidad de la Especie , Esputo/metabolismo