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1.
Tech Coloproctol ; 27(12): 1219-1225, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37036637

RESUMEN

PURPOSE: When an optical colonoscopy is carried out, Scope Guide can assist the endoscopist in determining the localization. In colon capsule endoscopy (CCE), this support is not available. To our knowledge, the interobserver agreement on landmark identification has never been studied. This study aims to investigate the interobserver agreement on landmark identification in CCE. METHODS: An interobserver study was carried out comparing the landmark identification (the ileocecal valve, hepatic flexure, splenic flexure, and anus) in CCE investigations between an external private contractor and three in-house CCE readers with different levels of experience. All CCE investigations analyzed in this study were carried out as a part of the Danish screening program for colorectal cancer. Patients were between 50 and 74 years old with a positive fecal immunochemical test (FIT). A random sample of 20 CCE investigations was taken from the total sample of more than 800 videos. RESULTS: Overall interobserver agreement on all landmarks was 51%. Interobserver agreement on the first cecal image (ileocecal valve), hepatic flexure, splenic flexure, and last rectal image (anus) was 72%, 29%, 22%, and 83%, respectively. The overall interobserver agreement, including only examinations with adequate bowel preparation (n = 16), was 54%, and for individual landmarks, 73%, 32%, 24%, and 85%. CONCLUSION: Overall interobserver agreement on all four landmarks from CCE was poor. Measures are needed to improve landmark identification in CCE investigations. Artificial intelligence could be a possible solution to this problem.


Asunto(s)
Endoscopía Capsular , Neoplasias Colorrectales , Humanos , Persona de Mediana Edad , Anciano , Variaciones Dependientes del Observador , Inteligencia Artificial , Neoplasias Colorrectales/diagnóstico por imagen , Estudios Prospectivos , Colonoscopía/métodos
2.
J Clin Microbiol ; 56(4)2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29212705

RESUMEN

New data from the years 2012 to 2015 from the Danish National Fungemia Surveillance are reported, and epidemiological trends are investigated in a 12-year perspective (2004 to 2015). During 2012 to 2015, 1,900 of 1,939 (98%) fungal bloodstream isolates were included. The average incidence was 8.4/100,000 inhabitants, and this appears to represent a stabilizing trend after the increase to 10.1/100,000 in 2011. The incidence was higher in males than females (10.0 versus 6.8) and in patients above 50 years, and those changes were mainly driven by an increasing incidence among 80-to-89-year-old males (65.3/100,000 in 2014 to 2015). The proportion of Candida albicans isolates decreased from 2004 to 2015 (64.4% to 42.4%) in parallel with a doubling of the proportion of Candida glabrata isolates (16.5% to 34.6%, P < 0.0001). C. glabrata was more common among females (34.0% versus 30.4% in males). Following an increase in 2004 to 2011, the annual drug use stabilized during the last 2 to 3 years of that time period but remained higher than in other Nordic countries. This was particularly true for the fluconazole and itraconazole use in the primary health care sector, which exceeded the combined national levels of use of these compounds in each of the other Nordic countries. Fluconazole susceptibility decreased (68.5%, 65.2%, and 60.6% in 2004 to 2007, 2008 to 2011, and 2012 to 2015, respectively, P < 0.0001), and echinocandin resistance emerged in Candida (0%, 0.6%, and 1.7%, respectively, P < 0.001). Amphotericin B susceptibility remained high (98.7%). Among 16 (2.7%) echinocandin-resistant C. glabrata isolates (2012 to 2015), 13 harbored FKS mutations and 5 (31%) were multidrug resistant. The epidemiological changes and the increased incidence of intrinsic and acquired resistance emphasize the importance of continued surveillance and of strengthened focus on antifungal stewardship.


Asunto(s)
Candida/aislamiento & purificación , Farmacorresistencia Fúngica Múltiple/genética , Monitoreo Epidemiológico , Fungemia/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Anfotericina B/farmacología , Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/genética , Candida albicans/efectos de los fármacos , Candida albicans/genética , Candida albicans/aislamiento & purificación , Candida glabrata/efectos de los fármacos , Candida glabrata/genética , Candida glabrata/aislamiento & purificación , Dinamarca/epidemiología , Equinocandinas/farmacología , Femenino , Fluconazol/farmacología , Fungemia/microbiología , Humanos , Incidencia , Itraconazol/farmacología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Factores Sexuales
3.
Epidemiol Infect ; 145(12): 2594-2602, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28689506

RESUMEN

The surveillance of Clostridium difficile (CD) in Denmark consists of laboratory based data from Departments of Clinical Microbiology (DCMs) sent to the National Registry of Enteric Pathogens (NREP). We validated a new surveillance system for CD based on the Danish Microbiology Database (MiBa). MiBa automatically collects microbiological test results from all Danish DCMs. We built an algorithm to identify positive test results for CD recorded in MiBa. A CD case was defined as a person with a positive culture for CD or PCR detection of toxin A and/or B and/or binary toxin. We compared CD cases identified through the MiBa-based surveillance with those reported to NREP and locally in five DCMs representing different Danish regions. During 2010-2014, NREP reported 13 896 CD cases, and the MiBa-based surveillance 21 252 CD cases. There was a 99·9% concordance between the local datasets and the MiBa-based surveillance. Surveillance based on MiBa was superior to the current surveillance system, and the findings show that the number of CD cases in Denmark hitherto has been under-reported. There were only minor differences between local data and the MiBa-based surveillance, showing the completeness and validity of CD data in MiBa. This nationwide electronic system can greatly strengthen surveillance and research in various applications.


Asunto(s)
Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/epidemiología , Monitoreo Epidemiológico , Vigilancia de la Población/métodos , Infecciones por Clostridium/diagnóstico , Infecciones por Clostridium/microbiología , Recuento de Colonia Microbiana , Dinamarca/epidemiología , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/epidemiología , Enterocolitis Seudomembranosa/microbiología , Humanos , Reacción en Cadena de la Polimerasa
4.
Antimicrob Agents Chemother ; 60(3): 1500-8, 2015 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-26711776

RESUMEN

The prevalence of intrinsic and acquired resistance among colonizing Candida isolates from patients after candidemia was investigated systematically in a 1-year nationwide study. Patients were treated at the discretion of the treating physician. Oral swabs were obtained after treatment. Species distributions and MIC data were investigated for blood and posttreatment oral isolates from patients exposed to either azoles or echinocandins for <7 or ≥ 7 days. Species identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing, susceptibility was examined by EUCAST EDef 7.2 methodology, echinocandin resistance was examined by FKS sequencing, and genetic relatedness was examined by multilocus sequence typing (MLST). One hundred ninety-three episodes provided 205 blood and 220 oral isolates. MLST analysis demonstrated a genetic relationship for 90% of all paired blood and oral isolates. Patients exposed to azoles for ≥ 7 days (n = 93) had a significantly larger proportion of species intrinsically less susceptible to azoles (particularly Candida glabrata) among oral isolates than among initial blood isolates (36.6% versus 12.9%; P < 0.001). A similar shift toward species less susceptible to echinocandins among 85 patients exposed to echinocandins for ≥ 7 days was not observed (4.8% of oral isolates versus 3.2% of blood isolates; P > 0.5). Acquired resistance in Candida albicans was rare (<5%). However, acquired resistance to fluconazole (29.4%; P < 0.05) and anidulafungin (21.6%; P < 0.05) was common in C. glabrata isolates from patients exposed to either azoles or echinocandins. Our findings suggest that the colonizing mucosal microbiota may be an unrecognized reservoir of resistant Candida species, especially C. glabrata, following treatment for candidemia. The resistance rates were high, raising concern in general for patients exposed to antifungal drugs.


Asunto(s)
Antifúngicos/farmacología , Candida/efectos de los fármacos , Candidemia/tratamiento farmacológico , Candidemia/microbiología , Farmacorresistencia Fúngica/efectos de los fármacos , Anciano , Antifúngicos/uso terapéutico , Candida/clasificación , Candida/patogenicidad , Dinamarca , Femenino , Fluconazol/uso terapéutico , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus
5.
J Hosp Infect ; 146: 66-75, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38354955

RESUMEN

OBJECTIVES: To describe the current organization and implementation of formalized, multi-disciplinary hospital-based antimicrobial stewardship (AMS) structures in Denmark, the Faroe Islands and Greenland. METHODS: A structured electronic questionnaire was sent to all trainees and specialists in clinical microbiology (N=207) and infectious diseases (N=260), as well as clinical pharmacists (N=20) and paediatricians (N=10) with expertise in infectious diseases. The survey had 30 multiple-choice, rating-scale, and open-ended questions based on an international consensus checklist for hospital AMS, adapted to a Danish context. RESULTS: Overall, 145 individual responses representing 20 hospitals were received. Nine hospitals (45%) reported a formal AMS strategy, eight (40%) a formal organizational multi-disciplinary structure and a multi-disciplinary AMS team, and six (30%) a designated professional as a leader of the AMS team. A majority of hospitals reported access to updated guidelines (80%) and regularly monitored and reported the quantity of antibiotics prescribed (70% and 65%, respectively). Only one hospital (5%) reported a dedicated, sustainable and sufficient AMS budget, three hospitals (15%) audited courses of therapy for specific agents/clinical conditions and four hospitals (20%) had a document clearly defining roles, procedures of collaboration and responsibilities for AMS. A total of 42% of all individual respondents had received formal AMS training. Main barriers were a lack of financial resources (52%), a lack of mandate from the hospital management (30%) and AMS not being a priority (18%). CONCLUSIONS: Core elements important for multi-disciplinary hospital-based AMS can be strengthened in Danish hospitals. Funding, clear mandates, prioritization from the hospital management and the implementation of multi-disciplinary AMS structures may help close the identified gaps.


Asunto(s)
Programas de Optimización del Uso de los Antimicrobianos , Enfermedades Transmisibles , Humanos , Groenlandia , Hospitales , Dinamarca
6.
Scand J Med Sci Sports ; 23(1): 74-83, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21812820

RESUMEN

To compare the effects of three 7-week interval training programs varying in work period duration but matched for effort in trained recreational cyclists. Thirty-five cyclists (29 male, 6 female, VO(2peak) 52 ± 6 mL kg/min) were randomized to four training groups with equivalent training the previous 2 months (∼6 h/wk, ∼1.5 int. session/wk). Low only (n=8) trained 4-6 sessions/wk at a low-intensity. Three groups (n=9 each) trained 2 sessions/wk × 7 wk: 4 × 4 min, 4 × 8 min, or 4 × 16 min, plus 2-3 weekly low-intensity bouts. Interval sessions were prescribed at the maximal tolerable intensity. Interval training was performed at 88 ± 2, 90 ± 2, and 94 ± 2% of HR(peak) and 4.9, 9.6, and 13.2 mmol/L blood lactate in 4 × 16, 4 × 8, and 4 × 4 min groups, respectively (both P<0.001). 4 × 8 min training induced greater overall gains in VO(2) peak, power@VO(2) peak, and power@4 mM bLa- (Mean ± 95%CI): 11.4 (8.0-14.9), vs 4.2 (0.4-8.0), 5.6 (2.1-9.1), and 5.5% (2.0-9.0) in Low, 4 × 16, and 4 × 4 min groups, respectively (P<0.02 for 4 × 8 min vs all other groups). Interval training intensity and accumulated duration interact to influence the adaptive response. Accumulating 32 min of work at 90% HR max induces greater adaptive gains than accumulating 16 min of work at ∼95% HR max despite lower RPE.


Asunto(s)
Adaptación Fisiológica , Ciclismo/fisiología , Ejercicio Físico/fisiología , Resistencia Física/fisiología , Adulto , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Educación y Entrenamiento Físico/métodos , Factores de Tiempo
7.
Indoor Air ; 21(3): 219-30, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21204991

RESUMEN

UNLABELLED: More than 30 years after the First International Indoor Climate Symposium, ten researchers from the USA, Slovakia, Sweden, and Denmark gathered to review the current status of indoor environmental research. We initiated our review with discussions during the 1-day meeting and followed that with parallel research and writing efforts culminating with internal review and revision cycles. In this paper, we present our choices for the most important research findings on indoor environmental quality from the past three decades followed by a discussion of the most important research questions in our field today. We then continue with a discussion on whether there are research areas for which we can 'close the book' and say that we already know what is needed. Finally, we discuss whether we can maintain our identity in the future or it is time to team up with new partners. PRACTICAL IMPLICATIONS: In the early years of this field, the accumulated knowledge was small and it was possible for any researcher to acquire a complete understanding. To do so has become impossible today as what we know has grown to exceed the learning capacity of any person. These circumstances challenge us to work collectively to synthesize what we do know and to define clearly what remains to be learned. If we fail to do these things well, we risk repeating research without memory, an inefficiency that we cannot afford.


Asunto(s)
Contaminantes Atmosféricos/historia , Contaminación del Aire Interior/historia , Salud Ambiental/historia , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/efectos adversos , Contaminación del Aire Interior/prevención & control , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Investigación/historia , Investigación/tendencias
8.
Euro Surveill ; 14(16)2009 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-19389341

RESUMEN

We report an outbreak of Clostridium difficile PCR ribotype 027 in Denmark. The outbreak includes to date 73 cases from the area north of Copenhagen, but there may be related cases elsewhere in Zealand. Most infections are healthcare-associated and in patients who previously received antibiotic treatment. The strain is resistant to moxifloxacin, erythromycin, and clindamycin, and carries genes for toxin A, toxin B, and for the binary toxin. The antimicrobial pattern differs from that of the strain involved in a small cluster in Denmark in 2006-2007. Because of this outbreak, hygienic measures in the involved hospitals have been reinforced. Nationwide, microbiological laboratories were alerted to the outbreak and encouraged to send isolates for toxin profiling and PCR ribotyping.


Asunto(s)
Clostridioides difficile/aislamiento & purificación , Brotes de Enfermedades , Enterocolitis Seudomembranosa/epidemiología , Enterocolitis Seudomembranosa/microbiología , Ribotipificación/métodos , Anciano , Anciano de 80 o más Años , Secuencia de Bases , Dinamarca/epidemiología , Brotes de Enfermedades/prevención & control , Enterocolitis Seudomembranosa/diagnóstico , Humanos
9.
J Appl Microbiol ; 105(6): 2231-8, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19016973

RESUMEN

AIMS: To examine the activity of bacteria involved in cathodic depolarization and surface corrosion on stainless steel in an in situ model system. METHODS AND RESULTS: The microautoradiographic technique (MAR) was used to evaluate the activity of bacterial populations on stainless steel surfaces with a single cell resolution. Anaerobic uptake and fixation of (14)C-labelled bicarbonate occurred within corrosion sites in the absence of atmospheric hydrogen or other external electron donors, whereas it was taken up and fixed by bacteria at all other stainless steel surfaces in the presence of atmospheric hydrogen. This indicates that the bacteria utilized electrons originating from the corrosion sites due to the ongoing corrosion (cathodic depolarization). CONCLUSION: Under in situ conditions, bacteria were fixating (14)C-labelled bicarbonate at corrosion sites in the absence of atmospheric hydrogen. This indicates that electrons transferred to the bacteria provided energy for bicarbonate fixation due to cathodic depolarization. SIGNIFICANCE AND IMPACT OF THE STUDY: Application of the MAR method showed ongoing biocorrosion in the applied in situ model system and allowed in situ examination of bacterial activity on a single cell level directly on a metal surface providing information about potential corrosion mechanisms. Furthermore, application of fluorescence in situ hybridization in combination with MAR allows for identification of the active bacteria.


Asunto(s)
Autorradiografía/métodos , Corrosión , Acero Inoxidable , Bacterias Anaerobias/metabolismo , Bicarbonatos/metabolismo , Biopelículas , Recuento de Colonia Microbiana , Electroquímica
10.
Int J Infect Dis ; 76: 58-63, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30176293

RESUMEN

BACKGROUND: Denmark has a high incidence rate of candidaemia. A Nordic study suggested a higher Danish prevalence of haematological malignancies as an underlying reason. This nationwide study ascertained clinical characteristics of Danish candidaemia patients and investigated potential factors contributing to the high incidence and mortality. METHODS: Microbiological and clinical data for candidaemia patients in 2010-2011 were retrieved. 30-day mortality was estimated by hazard ratios (HR) with 95% confidence intervals (CI, Cox regression). RESULTS: Data were available for 912/973 candidaemia episodes (93.7%). Intensive care unit (ICU) held the largest share of patients (43.2%). Prevalent host factors were multi-morbidity (≥2 underlying diseases, 74.2%) and gastrointestinal disease (52.5%). Haematological disease was infrequent (7.8%). Risk factors included antibiotic exposure (90.5%), CVC (71.9%) and Candida colonisation (66.7%). 30-day mortality was 43.4%, and 53.6% in ICU. Mortality was lower for patients with recent abdominal surgery (HR 0.70, 95% CI: 0.54-0.92). CONCLUSION: A substantial prevalence of multi-morbidity and a high 30-day mortality was found. We hypothesise, that an increasing population of severely ill patients with prolonged supportive treatment and microbiological testing may in part explain the high candidaemia incidence in Denmark. Nationwide studies are warranted to clarify this issue.


Asunto(s)
Candidemia/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Candidemia/etiología , Candidemia/mortalidad , Dinamarca/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Factores de Riesgo
11.
Clin Microbiol Infect ; 13(9): 863-72, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17686138

RESUMEN

This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin-producing E. coli (VTEC), isolated in a case-control study of Danish children aged <5 years. Among 424 children with diarrhoea and 866 healthy controls, EPEC and VTEC were more prevalent in cases (2.4% and 2.6%, respectively) than in controls (0.7% and 0.7%, respectively). There was a high frequency of A/EEC isolates (n = 121), but these were equally prevalent in cases (11.3%) and controls (12.5%), and comprised a heterogeneous distribution of O:H serotypes. The intimin (eae) subtypes in A/EEC isolates showed an even distribution; the eae-gamma subtype predominated in classical EPEC cases. The virulence genes encoding the bundle-forming pilus (bfpA) and enteroaggregative heat-stable enterotoxin (astA) were rare among all isolates, and seemed to be of limited pathogenic importance in this population. Virulence characterisation of A/EEC isolates did not reveal any significant differences between cases and controls. Colonisation of children with A/EEC was associated with contact with sheep or goats (OR 2.2). The role of A/EEC, not being VTEC or belonging to the classical EPEC serotypes, requires further clarification, but serotyping is useful in discriminating between EPEC and A/EEC strains.


Asunto(s)
Adhesinas Bacterianas/genética , Diarrea/microbiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Proteínas Fimbrias/fisiología , Adhesinas Bacterianas/metabolismo , Niño , Preescolar , Escherichia coli/aislamiento & purificación , Proteínas de Escherichia coli/metabolismo , Heces/microbiología , Proteínas Fimbrias/genética , Fimbrias Bacterianas/fisiología , Humanos , Lactante , Mucosa Intestinal/microbiología , Pruebas de Sensibilidad Microbiana , Virulencia/genética
16.
Diabetes ; 48(8): 1508-14, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10426366

RESUMEN

To identify abnormally expressed genes contributing to muscle insulin resistance in type 2 diabetes, we screened the mRNA populations from normal and diabetic human skeletal muscle using cDNA differential display and isolated abnormally expressed cDNA clones of mitochondrial-encoded NADH dehydrogenase 1 (ND1), cytochrome oxidase 1, tRNA(leu), and displacement loop. We then measured mRNA expression of these mitochondrial genes using a relative quantitative polymerase chain reaction method in biopsies taken before and after an insulin clamp in 12 monozygotic twin pairs discordant for type 2 diabetes and 12 matched control subjects and in muscle biopsies taken after an insulin clamp from 13 subjects with type 2 diabetes, 15 subjects with impaired glucose tolerance, and 14 subjects with normal glucose tolerance. Insulin infusion increased mRNA expression of ND1 from 1.02 +/- 0.04 to 2.55 +/- 0.30 relative units (P < 0.001) and of cytochrome oxidase 1 from 0.80 +/- 0.01 to 1.24 +/- 0.10 relative units (P < 0.001). The ND1 response to insulin correlated with glucose uptake (r = 0.46, P = 0.002). Although the rate of insulin-mediated glucose uptake was decreased in the diabetic versus the nondiabetic twins (5.2 +/- 0.7 vs. 8.5 +/- 0.8 mg x kg(-1) fat-free mass x min(-1), P < 0.01), insulin-stimulated ND1 expression was not significantly different between them (2.4 +/- 0.5 vs. 2.7 +/- 0.5 relative units). Neither was there any significant intrapair correlation of ND1 expression between the monozygotic twins (r = -0.15, NS). We conclude that insulin upregulates mitochondrial-encoded gene expression in skeletal muscle. Given the positive correlation between ND1 expression and glucose uptake and the lack of intrapair correlation between monozygotic twins, mitochondrial gene expression may represent an adaptation to intracellular glucose flux rather than an inherited trait.


Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Glucosa/metabolismo , Insulina/farmacología , Mitocondrias/fisiología , Músculo Esquelético/metabolismo , Anciano , ADN Complementario/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Enfermedades en Gemelos/genética , Femenino , Regulación de la Expresión Génica/fisiología , Humanos , Resistencia a la Insulina/fisiología , Masculino , Persona de Mediana Edad , Valores de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Gemelos Monocigóticos
18.
Arch Ophthalmol ; 101(12): 1920-6, 1983 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6197050

RESUMEN

Human corneas were studied by means of electron microscopy after culture at 31 degrees C for two to 20 days in a medium containing 8% dextran T 500. Dextran T 500, a strong osmotic agent, was included in the culture medium to prevent excessive swelling of the cornea. In order to exclude the possibility that the observed effects were the result of osmotic changes during fixation, in each experiment, fixatives with different osmolalities were used (430, 574, 727, and 812 mOsm). After 8, 16, and 20 days of culture, vacuoles appeared that were filled with dextran; the cytoplasm was completely filled with these vacuoles. The vacuolization was not limited to the endothelium, but was also observed in stromal keratocytes and to a limited extent in the epithelium. It was concluded that the monolayer of endothelium was still intact after 20 days of culture in medium containing 8% dextran T 500, and, secondly, that the dextran might have been taken up by endocytosis. Whether or not the uptake of dextran has a long-term toxic effect on the corneal cells remains to be elucidated.


Asunto(s)
Córnea/ultraestructura , Dextranos/farmacología , Microscopía Electrónica , Adolescente , Adulto , Anciano , Medios de Cultivo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Concentración Osmolar , Ósmosis/efectos de los fármacos
19.
FEMS Microbiol Lett ; 182(2): 319-25, 2000 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-10620686

RESUMEN

We have investigated the capacity of a well-defined Escherichia coli fimB strain, AAEC350 (a derivative of MG1655), to express type 1 fimbriae under various growth conditions. The expression of type 1 fimbriae is phase-variable due to the inversion of a 314-bp DNA segment. Two tyrosine recombinases, FimB and FimE, mediate the inversion of the phase switch. FimB can carry out recombination in both directions, whereas the current evidence suggests that FimE-catalyzed switching is on-to-off only. We show here that AAEC350 is in fact capable of off-to-on phase switching and type 1 fimbrial expression under aerobic static growth conditions. The phase switching is mediated by FimE, and allows emerging fimbriate AAEC350 to outgrow their non-fimbriate counterparts by pellicle formation. Following inversion of the phase switch, this element can remain phase-locked in the on orientation due to integration of insertion sequence elements, viz. IS1 or IS5, at various positions in either the fimE gene or the phase switch.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Escherichia coli , Escherichia coli/genética , Fimbrias Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Integrasas , Aglutinación , Proteínas Bacterianas/genética , Medios de Cultivo , Elementos Transponibles de ADN , Proteínas de Unión al ADN/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Escherichia coli/ultraestructura , Reacción en Cadena de la Polimerasa/métodos , Recombinación Genética , Análisis de Secuencia de ADN
20.
J Hosp Infect ; 31(4): 295-304, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8926379

RESUMEN

In a previous study we found a considerably higher mortality rate in patients with nosocomial (NO) compared with community-acquired (CA) Escherichia coli bacteraemia. To establish whether this was due to host differences or to differences in the infecting bacteria, we compared 205 NO with 172 CA bacteraemic isolates of E. coli with respect to serotype, virulence factors and antimicrobial susceptibility. Overall the six most frequent O antigens were O18ac, O6, O1, O2, O15 and O75, respectively. The six most frequent capsular antigens were K1, K5, K52, K2, K7 and K34, respectively. No major differences were found regarding O-antigens, capsular antigens, production of haemolysin, P-fimbriation, serum sensitivity or antimicrobial susceptibility. Surprisingly we found 17 strains of serotype O15:K52:[H1] of both NO (eight) and CA (nine) origin with similar phenotypic characteristics to a strain causing a CA outbreak in London 1986-1987. Possibly the Danish and the English strains belong to the same clone. Our findings argue against the existence of a distinct NO flora. NO E. coli bacteraemia strains seem to originate primarily from the patients' own flora.


Asunto(s)
Bacteriemia/microbiología , Infecciones Comunitarias Adquiridas/microbiología , Infección Hospitalaria/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/clasificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia/epidemiología , Distribución de Chi-Cuadrado , Niño , Preescolar , Infecciones Comunitarias Adquiridas/epidemiología , Infección Hospitalaria/epidemiología , Dinamarca/epidemiología , Farmacorresistencia Microbiana , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/epidemiología , Humanos , Lactante , Recién Nacido , Persona de Mediana Edad , Serotipificación , Virulencia
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