RESUMEN
Clostridioides difficile has been identified as one of the primary etiologic agents of nosocomial diarrhea and pseudomembranous colitis in humans and other mammals associated following broad-spectrum antibiotics use. In Rio de Janeiro, Brazil we describe a case of C. difficile infection (CDI) in a 13-year-old male dog.
Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Colitis , Enfermedades de los Perros , Enterocolitis Seudomembranosa , Animales , Brasil , Infecciones por Clostridium/diagnóstico , Infecciones por Clostridium/tratamiento farmacológico , Infecciones por Clostridium/veterinaria , Colitis/diagnóstico , Colitis/tratamiento farmacológico , Colitis/veterinaria , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/microbiología , Perros , MasculinoRESUMEN
BACKGROUND: Menopausal transition is a physiological process encompassing hormonal and body changes that impact women's health and life quality. This period may be characterized by the Stages of Reproductive Aging Workshop (STRAW + 10) criteria using menstrual patterns. Use of the STRAW + 10 is uncertain in HIV infection. We aimed to characterize menopausal transition in women with HIV (WWH) using the STRAW + 10 criteria, hormonal measures and menopause symptoms. METHODS: We performed a cross-sectional study, nested to the HIV-Infected Women's Cohort, in Rio de Janeiro, Brazil. Eligible women included those aged 30 years or older, without clinical or surgical menopause, hormonal contraception, replacement therapy and ovarian disorders. We conducted face-to-face interviews and collected blood samples for follicle stimulating hormone (FSH) and estradiol measures. RESULTS: We enrolled 328 WWH (28.3% of women in the cohort). The distribution of age, hormonal levels and reported symptoms per each STRAW + 10 stage was consistent with the expected distribution in the menopausal transition. Age and FSH significantly increased and estradiol decreased from stage -2 (7 + days of menstrual delay) to stage +2 (8 + years of amenorrhea). CONCLUSIONS: The present results support use of the STRAW + 10 to characterize the menopausal transition of WWH with good clinical and immunological control.
Asunto(s)
Envejecimiento/fisiología , Infecciones por VIH/fisiopatología , VIH , Menopausia/fisiología , Adulto , Brasil , Estudios de Cohortes , Estudios Transversales , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Persona de Mediana EdadRESUMEN
Bacteroides fragilis is an anaerobic bacteria component of human intestinal microbiota and agent of infections. In the host B. fragilis interacts with macrophages, which produces toxic radicals like NO. The interaction of activated mice peritoneal macrophages with four strains of B. fragilis was evaluated on this study. Previously was shown that such strains could cause metabolic and morphologic alterations related to macrophage death. In this work propidium iodide staining showed the strains inducing macrophage necrosis in that the labeling was evident. Besides nitroblue tetrazolium test showed that B. fragilis stimulates macrophage to produce oxygen radicals. In vivo assays performed in BalbC mice have results similar to those for in vitro tests as well as scanning electron microscopy, which showed the same surface pore-like structures observed in vitro before. The results revealed that B. fragilis strains studied lead to macrophage death by a process similar to necrosis.
Asunto(s)
Infecciones por Bacteroides/microbiología , Infecciones por Bacteroides/patología , Bacteroides fragilis/patogenicidad , Macrófagos Peritoneales/microbiología , Macrófagos Peritoneales/patología , Animales , Femenino , Macrófagos Peritoneales/metabolismo , Ratones , Ratones Endogámicos BALB C , Necrosis/microbiología , Necrosis/patología , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Bacteroides fragilis is a component of the normal intestinal flora and an important pathogen in nonintestinal endogenous infections. It has been associated with enteric infections and has already been detected in polluted water. In order to evaluate the genetic diversity of B. fragilis, a total of 31 isolates and two reference strains were examined. This collection included strains from nonintestinal infections [12], intestinal infections [5], intestinal microflora [10], aquatic environments [4], and the reference strains ATCC 25285 and ATCC 23745. DNA fingerprints were detected using two separate PCR reactions with different arbitrary primers. The computer-assisted system Taxotron (Institut Pasteur, Dr P. Grimont) was used to analyze the profiles obtained and dendrograms were generated. By using a distance of 0.65 as the threshold, two clusters (hereafter referred to as genotypes I and II) were defined. Strains of differents origins could be distributed into both genotypes. We were unable to detect any obvious correlation between a given genotype and the specific disease or the source of the corresponding strains.
Asunto(s)
Bacteroides fragilis/aislamiento & purificación , Bacteroides fragilis/clasificación , Bacteroides fragilis/genética , Variación Genética , Intestinos/microbiología , Reacción en Cadena de la Polimerasa/métodos , Microbiología del Agua , Contaminación del AguaRESUMEN
Bacteroides fragilis, a component of the normal flora and an important anaerobic pathogen in non-intestinal endogenous infections, has recently been associated with enteric diseases. In this study, 41 B. fragilis strains were analysed in relation to their genetic diversity. This collection included two reference strains (ATCC 23745 and 25285), 20 isolates from non-intestinal infections, six from intestinal infections, five from intestinal microflora and eight from an aquatic environment. The fingerprints were generated by using two repetitive sequences (REP and ERIC) as primers to PCR (rep-PCR). A dendrogram was obtained with the Taxotron Program. Three clusters (threshold genotypes I, II and III) were observed when the genetic distance was 0.30. These results confirm previous data found regarding the genotypical diversity of B. fragilis.
Asunto(s)
Infecciones por Bacteroides/microbiología , Bacteroides fragilis/clasificación , ADN Bacteriano/química , Bacteroides fragilis/genética , Análisis por Conglomerados , Secuencia de Consenso , Dermatoglifia del ADN/métodos , Variación Genética , Genotipo , Humanos , Intestinos/microbiología , Reacción en Cadena de la Polimerasa , Reproducibilidad de los Resultados , Microbiología del AguaRESUMEN
Bacteroides fragilis isolates from intestinal and non-intestinal infections, normal flora and the environment were examined for properties linked with interactions among cells in vitro. Different adhesion molecules were detected in agglutination assays with human erythrocytes and tests for auto-agglutination and adherence to human colon carcinoma cells (HT29). There was no correlation between these properties, indicating that independent molecules are involved. Treatment with trypsin, heat or EDTA inhibited agglutination and adherence, suggesting that these molecules are proteins. The lack of correlation with the origin of the strains did not permit any of these activities to be recognised as virulence markers. The expression of fragilysin, a protease associated with damage to intestinal cells and bacterial translocation, was examined. Only those strains from patients with diarrhoea expressed this protease activity in assays with HT29 cells and this was confirmed by specific PCR for the bft gene. The activity of fragilysin as an enterotoxin was confirmed in the rabbit intestinal ligated loop assay. The association of this property only with strains from intestinal infections indicates that it is too early to suggest this protease as a determinant factor of B. fragilis invasiveness.
Asunto(s)
Infecciones por Bacteroides/microbiología , Bacteroides fragilis/patogenicidad , Pruebas de Aglutinación , Animales , Anticoagulantes/farmacología , Adhesión Bacteriana/efectos de los fármacos , Bacteroides fragilis/efectos de los fármacos , Bacteroides fragilis/genética , Ácido Edético/farmacología , Enterotoxinas/genética , Células HT29 , Pruebas de Hemaglutinación , Calor , Humanos , Íleon/microbiología , Enfermedades Intestinales/microbiología , Metaloendopeptidasas/genética , Reacción en Cadena de la Polimerasa , Conejos , Propiedades de Superficie , Tripsina/farmacología , Virulencia , Microbiología del Agua , Contaminación del AguaRESUMEN
The results of this study show that there is a high frequency of resistant species in the Bacteroides fragilis group in the intestinal tract of children and adults in Brazil. B. fragilis was not studied. Of the 73 strains examined, B. distasonis was the most resistant species to penicillin, cefoxitin, cefotaxime and clindamycin. High rates of multiresistance were found, most commonly to penicillin and clindamycin (18 of 36 strains). High levels of beta-lactamase production were detected in isolates showing high resistance to penicillin and multiresistance to the cephamycins, suggesting a widespread dissemination of such resistance.
Asunto(s)
Antibacterianos/farmacología , Bacteroides fragilis/efectos de los fármacos , Bacteroides/efectos de los fármacos , Intestinos/microbiología , Adulto , Bacteroides/enzimología , Bacteroides/aislamiento & purificación , Bacteroides fragilis/enzimología , Brasil , Niño , Preescolar , Farmacorresistencia Bacteriana , Farmacorresistencia Bacteriana Múltiple , Humanos , Lactante , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/metabolismoRESUMEN
Susceptibility profiles of 99 Bacteroides fragilis strains for 9 antimicrobial agents were defined by using an agar dilution method. The isolates were uniformly susceptible to imipenen and metronidazole. All isolates were resistant to ampicillin. The resistance rates to amoxicillin/clavulanate, cefoxitin, cefotaxime, chloramphenicol, clindamycin and tetracycline were 3.0, 12.1, 15.1, 1.0, 18.2 and 75.7%, respectively. Sixteen strains showed reduced susceptibility to metronidazole (MIC 2-4 mg/L) but none had nim genes using PCR. All strains were also investigated for the presence of cepA, cfiA, cfxA, ermF and tetQ genes by PCR methodology and 92.9, 4.9, 24.2, 2 and 64.6% of the strains were respectively found positive. These results reflect the importance of surveys of susceptibility profiles and the relevance of detecting major genetic determinants to monitor the dissemination of these genes.
Asunto(s)
Antibacterianos/farmacología , Bacteroides fragilis/efectos de los fármacos , Bacteroides fragilis/genética , ADN Bacteriano , Farmacorresistencia Microbiana/genética , Pruebas de Sensibilidad MicrobianaRESUMEN
Clostridium difficile-associated disease (CDAD) is caused by a spore-forming bacterium and can result in highly variable disease, ranging from mild diarrhoea to severe clinical manifestations. Infections are most commonly seen in hospital settings and are often associated with on-going antibiotic therapy. Incidences of CDAD have shown a sustained increase worldwide over the last ten years and a hypervirulent C. difficile strain, PCR ribotype 027/REA type BI/North American pulsed-field (NAP) type 1 (027/BI/NAP-1), has caused outbreaks in North America and Europe. In contrast, only a few reports of cases in Latin America have been published and the hypervirulent strain 027/BI/NAP-1 has, so far, only been reported in Costa Rica. The potential worldwide spread of this infection calls for epidemiological studies to characterize currently circulating strains and also highlights the need for increased awareness and vigilance among healthcare professionals in currently unaffected areas, such as Latin America. This review attempts to summarize reports of C. difficile infection worldwide, especially in Latin America, and aims to provide an introduction to the problems associated with this pathogen for those countries that might face outbreaks of epidemic strains of C. difficile for the first time in the near future.
Asunto(s)
Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Brotes de Enfermedades , Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Países Desarrollados , Países en Desarrollo , Europa (Continente)/epidemiología , Genotipo , Humanos , América Latina/epidemiología , Tipificación Molecular , América del Norte/epidemiología , ProhibitinasRESUMEN
Heparan sulphate (HS) and the related polysaccharide, heparin, exhibit conformational and charge arrangement properties, which provide a degree of redundancy allowing several seemingly distinct sequences to exhibit the same activity. This can also be mimicked by other sulphated polysaccharides, both in overall effect and in the details of interactions and structural consequences of interactions with proteins. Together, these provide a source of active compounds suitable for further development as potential drugs. These polysaccharides also possess considerable size, which bestows upon them an additional useful property: the capability of disrupting processes comprising many individual interactions, such as those characterising the attachment of microbial pathogens to host cells. The range of involvement of HS in microbial attachment is reviewed and examples, which include viral, bacterial and parasitic infections and which, in many cases, are now being investigated as potential targets for intervention, are identified.
Asunto(s)
Bacterias/efectos de los fármacos , Adhesión Bacteriana/efectos de los fármacos , Heparitina Sulfato/química , Heparitina Sulfato/farmacología , Polisacáridos/química , Heparina/química , Heparina/farmacología , Humanos , Propiedades de SuperficieRESUMEN
The chemical composition of the lipophilic extracts of bark and core, of the Miscanthus x giganteus stalk, was studied by gas chromatography-mass spectrometry (GC-MS). Aromatic compounds, sterols, and fatty acids, followed by long-chain fatty alcohols, were the major families of components present in the M. x giganteus stalk. Aromatic compounds are more abundant in the M. x giganteus bark (521 mg/kg of bark), with vanillic acid, vanillin, and p-hydroxybenzaldehyde as the major compounds of this family. In the M. x giganteus core, sterols represent about 949 mg/kg of dry core with beta-sitosterol, 7-oxo-beta-sitosterol, stigmasterol, and campesterol as the major components. The detection of small amounts of esters in the GC-MS analysis with short columns explains the small increase in the abundance of the identified families after alkaline hydrolysis. The high content of valuable sterols and aromatic compounds in M. x giganteus and, particularly, in the core, which is considered a residue in most applications, can open new perspectives for the integrated upgrading of this grass within the biorefinery perspective.
Asunto(s)
Fenoles/análisis , Fitosteroles/análisis , Extractos Vegetales/química , Poaceae/química , Ácidos Grasos/análisis , Cromatografía de Gases y Espectrometría de Masas , Concentración de Iones de Hidrógeno , Hidrólisis , Odorantes/análisis , Corteza de la Planta/química , Tallos de la Planta/químicaRESUMEN
Heparan sulphate (HS) and the related polysaccharide, heparin, exhibit conformational and charge arrangement properties, which provide a degree of redundancy allowing several seemingly distinct sequences to exhibit the same activity. This can also be mimicked by other sulphated polysaccharides, both in overall effect and in the details of interactions and structural consequences of interactions with proteins. Together, these provide a source of active compounds suitable for further development as potential drugs. These polysaccharides also possess considerable size, which bestows upon them an additional useful property: the capability of disrupting processes comprising many individual interactions, such as those characterising the attachment of microbial pathogens to host cells. The range of involvement of HS in microbial attachment is reviewed and examples, which include viral, bacterial and parasitic infections and which, in many cases, are now being investigated as potential targets for intervention, are identified.
Asunto(s)
Humanos , Bacterias/efectos de los fármacos , Adhesión Bacteriana/efectos de los fármacos , Heparitina Sulfato/química , Heparitina Sulfato/farmacología , Polisacáridos/química , Heparina/química , Heparina/farmacología , Propiedades de SuperficieRESUMEN
The effects of subinhibitory concentrations of metronidazole, chloramphenicol, clindamycin and penicillin G on cell growth and neuraminidase activity of Bacteroides fragilis were tested in six strains from clinical specimens and two type collection strains. All showed significant inhibition of cell growth at one half the MIC after 24 h incubation. Metronidazole at one quarter the MIC was significantly inhibitory after 24 and 48 h incubation. The neuraminidase activity remained unaltered, in comparison with controls, when metronidazole and clindamycin were tested. Chloramphenicol reduced the enzyme activity at both one half and one quarter the MIC. On the other hand, penicillin G enhanced the neuraminidase activity, although the difference was not statistically significant. These in-vitro effects may simulate the behaviour of the bacteria in abscesses in vivo.
Asunto(s)
Bacteroides fragilis/crecimiento & desarrollo , Cloranfenicol/farmacología , Clindamicina/farmacología , Metronidazol/farmacología , Neuraminidasa/metabolismo , Penicilina G/farmacología , Bacteroides fragilis/efectos de los fármacos , Bacteroides fragilis/enzimología , Recuento de Colonia Microbiana , Pruebas de Sensibilidad Microbiana , Neuraminidasa/biosíntesisRESUMEN
The effects of subinhibitory concentrations of metronidazole on the general morphology, ultrastructure and charge and hydrophobicity of Bacteroides fragilis were investigated using transmission and scanning electron microscopy, and measurements of zeta-potentials and contact angles. Metronidazole treatment induced morphological alterations in B. fragilis. Cells became filamentous and showed a significant loss of cytoplasm. The surface anionogenicity and hydrophobicity of B. fragilis were enhanced by the drug treatment. Metronidazole, by modifying B. fragilis surface properties, could alter, indirectly, interactions with host cells.
Asunto(s)
Bacteroides fragilis/efectos de los fármacos , Metronidazol/farmacología , Bacteroides fragilis/crecimiento & desarrollo , Bacteroides fragilis/ultraestructura , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Propiedades de Superficie/efectos de los fármacosRESUMEN
It was observed that sialic acid and macromolecules rich in this sugar were able to inhibit the hemagglutination activity (HA) of Bacteroides fragilis strains in low concentrations. Reversion of the HA and also of the adsorption to beads of Sepharose coupled to bovine submaxillary mucin, by this sugar residue corroborated the recognition capacity of the bacterial lectin-like adhesin. However, when erythrocytes were treated with clostridial neuraminidase, an increase in the HA of some strains was observed. Protease treatment of erythrocytes abolished the HA, indicating that cell receptors of B. fragilis are probably a glycoprotein moiety.
Asunto(s)
Adhesinas Bacterianas , Adhesión Bacteriana , Proteínas Bacterianas/metabolismo , Bacteroides fragilis/metabolismo , Receptores Mitogénicos/metabolismo , Ácidos Siálicos/análisis , Hemaglutininas/metabolismo , Ácido N-Acetilneuramínico , Neuraminidasa/farmacología , Receptores Mitogénicos/efectos de los fármacos , Ácidos Siálicos/metabolismoRESUMEN
Fusobacterium nucleatum is a gram-negative non-spore-forming, non-motile, obligate anaerobic rod that is normally isolated from the oral cavity. Several studies have reported a significant heterogeneity within the F. nucleatum species. The aim of the present study was to analyze the clonal diversity of F. nucleatum strains isolated from intracanal infections and to evaluate the presence of Enterobacterial Repetitive Intergenic Consensus (ERIC)-like sequences in the genome of F. nucleatum. Samples were collected from 13 single-root teeth from adult patients, all having carious lesions, necrotic pulps and radiographic evidence of periradicular bone loss. F. nucleatum was isolated from two different patients (subjects 5 and 7) by culture. Amplification of 19 colonies from subject 5 and 15 colonies from subject 7 using ERIC primers resulted in four clonal types, two per subject. An intense amplicon of approximately 700 bp was generated by ERIC-PCR for all F. nucleatum isolates and F. nucleatum ssp. polymorphum ATCC 10953. The amplification reaction using primer 1254 confirmed the results obtained with the ERIC primer. Our findings indicate that DNA fingerprints provided by ERIC- and Arbitrarily Primed (AP)-PCR may constitute a powerful tool for investigating F. nucleatum clonal diversity.
Asunto(s)
Cavidad Pulpar/microbiología , Necrosis de la Pulpa Dental/microbiología , Infecciones por Fusobacterium/microbiología , Fusobacterium nucleatum/genética , Adulto , Pérdida de Hueso Alveolar/microbiología , Emparejamiento Base/genética , Células Clonales , Secuencia de Consenso/genética , Dermatoglifia del ADN , Cartilla de ADN/clasificación , Caries Dental/microbiología , Amplificación de Genes , Genoma Bacteriano , Genotipo , Humanos , Secuencias Repetitivas Esparcidas/genética , Enfermedades Periapicales/microbiología , Fenotipo , Reacción en Cadena de la PolimerasaRESUMEN
Thirteen strains of Bacteroides fragilis isolated from contaminated water or from cases of intestinal and non-intestinal infections were comparatively analyzed in order to detect a possible biological relationship among them. The observation of similar profiles among the two groups, regarding the capacity of inducing abscesses and some surface properties, may support the hypothesis that the species could also act as an exogenous pathogen.
Asunto(s)
Infecciones por Bacteroides/microbiología , Bacteroides fragilis/patogenicidad , Enfermedades Intestinales/microbiología , Microbiología del Agua , Absceso/microbiología , Aglutinación , Animales , Antígenos Bacterianos , Bacteroides fragilis/aislamiento & purificación , Bacteroides fragilis/metabolismo , Humanos , Ratones , Neuraminidasa/metabolismo , Propiedades de Superficie , VirulenciaRESUMEN
Surface vesicles (SV) defined by electron microscopy as outer membrane (OM) extrusions were detected in Bacteroides fragilis strains from distinct sources. A partial identity between SV and OM electrophoretic protein profiles, in addition to the microscopic analysis, may suggest the designation of OMSV. Sialidase activity, a virulence determinant, was associated with these sub-cellular structures in all the strains, but in an inverse relation to the vesicle quantity per cell. A commensal strain, previously defined as avirulent in an animal model, presented the lowest vesicle-associated sialidase activity and the greatest SV expression as opposed to what happened with clinical and environmental strains. These results seem to suggest that these surface components have a function in commensal stages of B. fragilis.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/análisis , Bacteroides fragilis/química , Bacteroides fragilis/ultraestructura , Membrana Celular/química , Membrana Celular/ultraestructura , HumanosRESUMEN
The epidemiology of antimicrobial resistance of clinical isolates and human intestinal strains of Bacteroides fragilis has assumed great importance in the last few years since this microorganism, like other members of the B. fragilis group, can be responsible for the spread of resistance determinants. It is possible that the presence of B. fragilis in polluted aquatic environments might contribute to the spread of resistance. The antimicrobial resistance profile of 44 clinical B. fragilis strains isolated from 1981-1988 and 1991-1998 from the University hospital of Rio de Janeiro, and of 17 faecal and 17 polluted aquatic environmental B. fragilis strains isolated between 1991 and 1998 was determined. The susceptibility tests against penicillin, cefoxitin, imipenem, meropenem, clindamycin, chloramphenicol and metronidazole were performed by Etest in Wilkins-Chalgren agar enriched with 5% sheep blood. Motivated by some high MIC values for cefoxitin and meropenem, the cfiA gene, which codes for a metallo-beta-lactamase, was investigated among all strains, using PCR amplification. The resistance to penicillin was high in the samples from 1981 to 1988 (92.9%) and also in those from 1991 to 1998 (100%), although the MIC90 decreased from 256 mg/L to 24 mg/L. An increase in the resistance level to clindamycin and cefoxitin was seen from one decade to the other, the MIC90 values changing from 4 mg/L to 12 mg/L and from 8 mg/L to 32 mg/L, respectively. The susceptibility profile for metronidazole, chloramphenicol, imipenem and meropenem remained stable, although two clinical strains showed MICs of 6 mg/L and 8 mg/L against meropenem. Almost all human intestinal strains were resistant to penicillin and all of them were susceptible to imipenem, meropenem, chloramphenicol and metronidazole. The MICs of meropenem against two strains isolated from a polluted aquatic environment were 6 mg/L and 32 mg/L. The cfiA gene was detected in five strains, two of which were isolated from clinical specimens against which the MIC values of cefoxitin were high and three from an aquatic environment, whose susceptibility to both cefoxitin and meropenem ranged from sensitive to resistant.