RESUMEN
OBJECTIVE: to evaluate the prevalence of nasal colonization with Staphylococcus aureus (SA) in active, independent community seniors and old people in a nursing home. DESIGN: cross-sectional brief questionnaire and screening culture of anterior nares specimens from 165 elders at a community centre and cross-sectional data from a recent survey in a nursing home. RESULTS: the prevalence of SA colonization in community seniors (27%) was similar to that in the nursing home (29%). The proportion of SA isolates that were methicillin-resistant was much lower in the community seniors (2.3%) than in the nursing-home residents (31%). There was less antibiotic resistance in those living at home. CONCLUSION: in community seniors the prevalence of SA colonization was similar to that in nursing-home residents, but the prevalence of methicillin-resistant SA was lower. Susceptibility patterns of antibiotics tested against the SA showed less resistance than isolates from nursing-home patients.
Asunto(s)
Cavidad Nasal/microbiología , Infecciones Estafilocócicas/epidemiología , Anciano , Antibacterianos/farmacología , Centros Comunitarios de Salud , Estudios Transversales , Femenino , Servicios de Salud para Ancianos , Hogares para Ancianos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Casas de Salud , Prevalencia , Staphylococcus aureus/efectos de los fármacosRESUMEN
BACKGROUND: We report a 1-year surveillance study that evaluates colonization and infection with ciprofloxacin-resistant gram-negative bacilli (CR GNB) and the relation to quinolone use and other possible risk factors in a proprietary skilled nursing facility (SNF) with no history of outbreaks. METHODS: Rectal swabs obtained quarterly were streaked on MacConkey agar with ciprofloxacin discs (5 microg) to screen for CR GNB and later were speciated and the antimicrobial susceptibilities were confirmed by standardized disc-diffusion tests. RESULTS: The mean prevalence of CR GNB colonization was 2.6% (range 0.9% to 5.3%). The colonization frequency was higher in the last survey than it was in the first survey. CR GNB-colonized strains included Pseudomonas species (21%), but more than half were non-Pseudomonas enterics such as Acinetobacter baumannii (25%), Proteus mirabilis (17%), and Providencia stuartii (13%). None of the patients who had colonization with CR GNB had subsequent infections with the same species. Patients with colonization had more exposure to ciprofloxacin and they were more likely to have been recently admitted from an acute-care hospital and have decubitus ulcers. During the study period, of 336 patients surveyed, 98 (29%) patients developed suspected infections and cultures were done; the infection rate was 4.7 per 1000 patient days. Of these infected patients, 59 (60%) were infected by GNBs; the infection rate was 2.3 per 1000 patient days. Nineteen percent of the GNB infections were treated with a quinolone. (Overall, quinolones constituted about 17% of antibiotic usage in the SNF). Only 3 (5%) of the patients infected with GNB were infected with CR GNB, including Pseudomonas and Providenci a species. The CR GNB infections involved multiple sites, multiple organisms, and long length of stay in the SNF. CONCLUSIONS: The findings indicate that in this community SNF, a low frequency of colonization or infection with CR GNB existed. Whether continued moderate use of quinolones will lead to increasing levels of CR GNB will require further study.
Asunto(s)
Antiinfecciosos , Portador Sano/microbiología , Ciprofloxacina , Infecciones por Bacterias Gramnegativas/microbiología , Anciano , Antiinfecciosos/uso terapéutico , California , Portador Sano/tratamiento farmacológico , Ciprofloxacina/uso terapéutico , Farmacorresistencia Microbiana , Femenino , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Humanos , Control de Infecciones , Estudios Longitudinales , Masculino , Tamizaje Masivo , Pruebas de Sensibilidad Microbiana , Prevalencia , Factores de Riesgo , Instituciones de Cuidados Especializados de EnfermeríaRESUMEN
Recent advances indicate soluble amyloid beta (A beta) protein is produced constitutively during normal metabolism of the amyloid precursor protein (APP). This has not been directly examined in human brain vascular tissues. Using a panel of well-characterized antibodies, here we show that increased amounts of soluble A beta were found in isolated vascular tissues from AD subjects compared to age-matched controls without significant Alzheimer pathology. Immunocytochemical analyses of isolated vessel preparations showed characteristic transverse patterns of A beta deposits in large vessels with smooth muscle, however, fine A beta deposits were apparent even in capillaries. A proportion of such A beta protein and potentially amyloidogenic carboxyl terminal fragments were released by solubilization and disruption of the vascular basement membrane by collagenase treatments. We further demonstrated by in vitro metabolic labelling that soluble A beta or an A beta-like peptide is associated and produced by cerebral microvessels, meningeal vessels and the choroid plexus isolated postmortem from human as well as rat brain. Compared to those from young rats, cerebral microvessels from aging rats showed increased release of carboxyl terminal fragments of APP and A beta-like peptide. Our observations provide the first direct demonstration that human vascular tissues produce soluble A beta, a product of the secretory pathway in APP processing. Our findings also suggest that aging associated alterations in the basement membranes are a factor in A beta accumulation that results in vascular amyloid deposition, the principal feature of cerebral amyloid angiopathy.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular , Plexo Coroideo/irrigación sanguínea , Meninges/irrigación sanguínea , Microcirculación/metabolismo , Anciano , Envejecimiento/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/análisis , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Humanos , Immunoblotting , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Fragmentos de Péptidos/análisis , Ratas , Ratas Endogámicas F344 , Valores de ReferenciaRESUMEN
Based on previous evidence suggesting abnormalities in the brain microvasculature, we examined basement membrane collagen in isolated cerebral microvessels (CMV) from subjects with Alzheimer's disease (AD) and age-matched controls. Concentrations of hydroxyproline, the principal constituent of collagen IV, were significantly increased by 55% in CMV from AD subjects compared to controls. This result was corroborated by the finding of 60% increased total collagen content in CMV as evident by the selective binding of Sirius red dye. Hydroxyproline and collagen concentrations in samples of cerebral cortex assayed in parallel were 6-20 times smaller than in CMV and were not changed between controls and AD subjects. To further differentiate AD and control samples, fractions of CMV were solubilized and the pepsin digested collagen proteins resolved by SDS-PAGE. Upon immunoblotting, AD samples with increased collagen revealed proportionally greater specific immunoreactivities detected by antibodies to collagen IV. Our observations suggest altered collagen IV content of cerebral vessels in subjects with AD that may affect brain microvascular functions.