RESUMEN
Staphylococcus aureus is the main pathogen responsible for bone and joint infections worldwide and is also capable of causing pneumonia and other invasive severe diseases. Panton-Valentine leukocidin (PVL) and methicillin-resistant S. aureus (MRSA) have been studied as factors related with severity in these infections. The aims of this study were to describe invasive community-acquired S. aureus (CA-SA) infections and to analyse factors related to severity of disease. Paediatric patients (aged 0-16 years) who had a CA-SA invasive infection were prospectively recruited from 13 centres in 7 European countries. Demographic, clinical and microbiological data were collected. Severe infection was defined as invasive infection leading to death or admission to intensive care due to haemodynamic instability or respiratory failure. A total of 152 children (88 boys) were included. The median age was 7.2 years (interquartile range, 1.3-11.9). Twenty-six (17%) of the 152 patients had a severe infection, including 3 deaths (2%). Prevalence of PVL-positive CA-SA infections was 18.6%, and 7.8% of the isolates were MRSA. The multivariate analysis identified pneumonia (adjusted odds ratio (aOR) 13.39 (95% confidence interval (CI) 4.11-43.56); p 0.008), leukopenia at admission (<3000/mm(3)) (aOR 18.3 (95% CI 1.3-259.9); p 0.03) and PVL-positive infections (aOR 4.69 (95% CI 1.39-15.81); p 0.01) as the only factors independently associated with severe outcome. There were no differences in MRSA prevalence between severe and nonsevere cases (aOR 4.30 (95% CI 0.68- 28.95); p 0.13). Our results show that in European children, PVL is associated with more severe infections, regardless of methicillin resistance.
Asunto(s)
Infecciones Comunitarias Adquiridas/patología , Índice de Severidad de la Enfermedad , Infecciones Estafilocócicas/patología , Staphylococcus aureus/aislamiento & purificación , Toxinas Bacterianas/análisis , Niño , Preescolar , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/mortalidad , Cuidados Críticos , Europa (Continente)/epidemiología , Exotoxinas/análisis , Femenino , Humanos , Lactante , Leucocidinas/análisis , Masculino , Estudios Prospectivos , Factores de Riesgo , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/mortalidad , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad , Análisis de Supervivencia , Factores de Virulencia/análisisRESUMEN
Staphylococcus lugdunensis has emerged as a significant human pathogen, with distinct clinical and microbiological characteristics. Our goal was to identify the virulence factors in S. lugdunensis recovered from infected patients of two Greek hospitals during a six-year period (2008-2013). A collection of 38 S. lugdunensis was tested for biofilm formation, antimicrobial susceptibility, clonal distribution, virulence factors (ica operon, fbl, atlL, vwbl, slush) and antibiotic resistance genes (mecA, ermC) carriage. Strains were classified into pulsotypes by pulsed-field gel electrophoresis (PFGE) of SmaI DNA digests. The majority (22) was isolated from skin and soft tissue infections (SSTIs), nine from deep-sited infections (DSIs), including three bacteraemias and seven from prosthetic device-associated infections (PDAIs). All isolates were oxacillin-susceptible, mecA-negative and fbl-positive. The highest resistance rate was detected for ampicillin (50%), followed by erythromycin and clindamycin (18.4%). Fourteen isolates (36.8%) produced biofilm, whereas 26/38 (68.4%) carried the ica operon. Biofilm formation was more frequent in isolates from PDAIs. Thirty-six strains (94.7%) carried atlL and 31 (81.6%) carried vwbl, whereas slush was detected in 15 (39.5%). PFGE revealed a low level of genetic diversity: strains were classified into seven pulsotypes, with two major clones (C: 22 and D: nine strains). Type C strains recovered from all infection sites prevailed in biofilm formation and ermC carriage, whereas type D strains associated with SSTIs and DSIs carried more frequently vwbl, slush or both genes. Despite susceptibility to antimicrobials, the clonal expansion and carriage of virulence factors, combined with biofilm-producing ability, render this species an important pathogen that should not be ignored.
Asunto(s)
Infecciones Estafilocócicas/microbiología , Staphylococcus lugdunensis/genética , Staphylococcus lugdunensis/aislamiento & purificación , Factores de Virulencia/genética , Adulto , Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Análisis por Conglomerados , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Femenino , Variación Genética , Genotipo , Grecia , Hospitales , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Staphylococcus lugdunensis/clasificación , Staphylococcus lugdunensis/patogenicidadRESUMEN
BACKGROUND: The KISS1/KISS1R system has been implicated in the physiology of reproduction and many studies have documented the stimulatory effect of kisspeptin on Gonadotropin-releasing Hormone (GnRH) and gonadotropin secretion. In addition, the KISS1/KISS1R system has been implicated in several pathophysiological processes, including cancer. MATERIALS AND METHODS: We examined the pattern of KISS1 and KISS1R expression in eutopic and ectopic endometrium tissues which were obtained from 24 women suffering from endometriosis and 16 control women who underwent laparoscopic excision for other benign gynecological diseases. RESULTS: Significant KISS1R expression was detected in 10 out of the 24 samples of eutopic endometrial biopsies of women suffering from endometriosis, while their matched biopsies of ectopic endometrial lesions did not reveal any KISS1R expression. KISS1R expression was not detected in the endometrial biopsies of control women. In addition, KISS1 expression was not detected in practically any the endometrial tissues of either control women or women with endometriosis. CONCLUSION: The expression of KISS1R in 10/24 samples of human endometrial biopsies of women suffering from endometriosis and the loss of its expression in the samples of matched ectopic endometrial tissues, suggests that the KISS1/KISS1R system may play a role in the pathophysiology of endometriosis only for a particular group of patients. Since KISS1 is not expressed by the endometrium and endometriotic tissue, it is conceivable that the activation of KISS1R in this particular group is mediated by KISS1 expression by non-endometrial tissues (endocrine action).
Asunto(s)
Coristoma/genética , Endometriosis/genética , Endometrio/metabolismo , Perfilación de la Expresión Génica , Kisspeptinas/genética , Receptores Acoplados a Proteínas G/genética , Adulto , Biopsia , Endometriosis/patología , Endometrio/patología , Femenino , Humanos , Receptores de Kisspeptina-1 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto JovenRESUMEN
The Kiss-1 gene encodes a secreted protein that is proteolytically cleaved to produce a number of structurally related peptides, with high interspecies conservation, globally termed kisspeptins. The original niche for the role of kisspeptin in human physiology is derived from cancer biology, with the loss of Kiss-1 expression being associated with poor prognosis in several malignancies. However, kisspeptin has recently emerged as a fundamental player in the field of reproductive biology. Genetic analysis of large consanguineous pedigrees by two independent groups led to the association of inactivating mutations of GPR54, the receptor which mediates kisspeptin action, with idiopathic hypogonadotropic hypogonadism. In the present paper the most salient aspects of the multifaceted role of kisspeptin in the reproductive system are reviewed, including the association of kisspeptin with the gonadal steroid feedback loop and the triggering of puberty onset.
Asunto(s)
Receptores Acoplados a Proteínas G/metabolismo , Reproducción/fisiología , Proteínas Supresoras de Tumor/metabolismo , Animales , Encéfalo/metabolismo , Gónadas/metabolismo , Humanos , Kisspeptinas , Mutación/genética , Pubertad/genética , Pubertad/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores de Kisspeptina-1 , Proteínas Supresoras de Tumor/genéticaRESUMEN
Tumor markers are widely used for screening certain tumors, however, their use in chronic hemodialysis (HD) patients in hemodialysis has been a controversial issue. To determine the reliability of the tumor markers, CA 15-3, CA 19-9, CA 125, alpha-fetoprotein and carcinoembryonic antigen (CEA), in chronic HD patients, and the impact of active hepatitis C on the variation of tumor markers values, we studied 30 patients (16 men and 14 women) aged from 40 to 78 years old (mean age: 54 + or - 5 years), on intermittent hemodialysis (with a mean duration of 10.5 years), and clinically free from neoplastic disease. The control group included 30 healthy volunteers. All subjects were of Greek origin and residents of the Korinthos region. The tumor markers were measured once in the control group and before and afterwards the hemodialysis, in the study group. Alpha fetoprotein was within normal limits in all the study patients, CA 125 was slightly increased in one (3.3%) patient, CA 15-3 levels were twice normal in 4 (13%) patients, CA 19-9 levels were twice normal in 5 (16%) patients, and CEA levels were twice normal in 4(13%) patients. More than half (7/13) of anti HCV positive and all Australian antigen positive patients had abnormal serum levels of CA 15-3 and CA 125 after hemodialysis treatment. We conclude that measurement of some tumor markers such as alfa-fetoprotein may be beneficial in HD patients. However, the elevated levels of other markers including CA 15-3 and CA 125 are not specific for neoplasms and related to active hepatitis C.
Asunto(s)
Biomarcadores de Tumor/sangre , Hepatitis C/sangre , Fallo Renal Crónico/terapia , Diálisis Renal , Adulto , Anciano , Antígeno Ca-125/sangre , Antígeno CA-19-9/sangre , Antígeno Carcinoembrionario/sangre , Estudios de Casos y Controles , Femenino , Grecia , Humanos , Fallo Renal Crónico/sangre , Masculino , Persona de Mediana Edad , Mucina-1/sangre , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factores de Tiempo , alfa-Fetoproteínas/metabolismoRESUMEN
A semi-solid fermentation process for the production of biodiesel from sweet sorghum is introduced. The microorganism used is the oleaginous fungus Mortierella isabellina, which is able to transform efficiently sugar to storage lipid. Kinetic experiments were performed at various water content percentages. The fungus consumed simultaneously sugars and nitrogen contained in sorghum and after nitrogen depletion the biomass growth was completed and oil accumulation began. Water content of 92% presented the highest oil efficiency of 11 g/100 g dry weight of substrate. The semi-solid process is shown to have certain advantages compared to liquid cultures or solid-state fermentation and gives oil of high quality.
Asunto(s)
Biotecnología/métodos , Fermentación/fisiología , Aceites/síntesis química , Sorghum/fisiología , Cinética , Mortierella/crecimiento & desarrollo , Aceites/análisis , Agua/químicaRESUMEN
We investigated the characteristics of 20 community acquired methicillin resistant Staphylococcus aureus (MRSA) strains isolated in a paediatric hospital in Athens. Eighteen of these, all isolated from skin and soft tissue infections, carried the Panton-Valentine leukocidin (PVL) determinants. They all were found resistant to fusidic acid, tetracycline and kanamycin, and displayed a PFGE pattern identical to that of the well-described ST80 CA-MRSA clone circulating in various European countries.
Asunto(s)
Resistencia a la Meticilina , Medición de Riesgo/métodos , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Niño , Infecciones Comunitarias Adquiridas/sangre , Infecciones Comunitarias Adquiridas/diagnóstico , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Femenino , Grecia/epidemiología , Hospitalización/estadística & datos numéricos , Humanos , Incidencia , Masculino , Vigilancia de la Población/métodos , Factores de Riesgo , Infecciones Estafilocócicas/sangre , Infecciones Estafilocócicas/microbiologíaRESUMEN
Calreticulin is a molecular chaperone to newly synthesized polypeptides. Previous studies suggested that calreticulin is probably a protein member of the Ro/La RNP complex. The aims of this study were (a) to investigate whether linear B cell epitopes of the Ro/La RNP complex are bound to calreticulin and (b) if the complex peptide-calreticulin is recognized specifically by anti-Ro autoantibodies. Calreticulin was isolated from either human or pig spleen using a multi-step purification method and found to interact preferentially with biotinylated peptides derived from the sequence of the Ro60 kD 175-184aa(10p) and 216-232aa(17p). The interaction of the peptide-calreticulin complex was favoured by the combination of heat treatment, divalent cations and ATP. La/SSB epitopes did not react with calreticulin. Peptides corresponding to La/SSB epitopes as well as the common epitope of Sm did not interact with calreticulin. Thirty-eight anti-Ro60 KD positive and 23 anti-Ro60 kD negative sera of patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) were tested. All anti-Ro60 kD positive sera bound the complex calreticulin-17p, while 95% of the same sera had activity against the complex calreticulin - 10p. Tested individually, calreticulin, pep10p and pep17p presented very low reactivity (8%, 11% and 29%, respectively) against anti-Ro60 kD positive sera. Anti-Ro60 KD negative sera did not exhibit significant reactivity either with calreticulin, 10rho and 17rho or with the complexes calreticulin - 10p and calreticulin-17p (<5%). These results suggest that calreticulin can induce conformation-dependent recognition of the Ro60 kD epitopes, leading eventually to their recognition by autoantibodies. This is the first time that such a relationship is shown between a chaperone protein and fragments of an intracellular autoantigen. This work also provides insights into the understanding of mechanisms for autoantibody production. Furthermore, this association can be proved useful for the development of new sensitive assays for autoantibody detection.
Asunto(s)
Autoanticuerpos/inmunología , Autoantígenos , Enfermedades Autoinmunes/inmunología , Linfocitos B/inmunología , Calreticulina/metabolismo , Epítopos/metabolismo , ARN Citoplasmático Pequeño , Ribonucleoproteínas/inmunología , Animales , Autoanticuerpos/análisis , Enfermedades Autoinmunes/metabolismo , Calreticulina/aislamiento & purificación , Estudios de Casos y Controles , Humanos , Lupus Eritematoso Sistémico/inmunología , Unión Proteica , Ribonucleoproteínas Nucleares Pequeñas/inmunología , Síndrome de Sjögren/inmunología , Porcinos , Temperatura , Proteínas Nucleares snRNP , Antígeno SS-BAsunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas , Proteínas Portadoras/genética , Hexosiltransferasas , Muramoilpentapéptido Carboxipeptidasa/genética , Mutación , Resistencia a las Penicilinas , Peptidil Transferasas , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/efectos de los fármacos , Adolescente , Niño , Preescolar , Farmacorresistencia Bacteriana Múltiple , Grecia , Humanos , Pruebas de Sensibilidad Microbiana , Proteínas de Unión a las Penicilinas , Infecciones Neumocócicas/microbiología , Reacción en Cadena de la Polimerasa , Serotipificación , Streptococcus pneumoniae/aislamiento & purificaciónRESUMEN
The antimicrobial susceptibility of 129 Campylobacter jejuni strains, isolated from hospitalized children with gastroenteritis, to five antimicrobials, including nalidixic acid, ciprofloxacin, erythromycin, ampicillin and co-amoxiclav, was determined. Isolates belonged to two time periods: group A contained strains isolated in 1987-1988; and group B 1998-2000. Antimicrobial susceptibility patterns differed significantly between the two groups with respect to quinolones, with an increase in the percentage of resistant strains in group B (30.6% versus 0% in group A), whereas erythromycin, ampicillin and co-amoxiclav were effective drugs in both groups.
Asunto(s)
Antibacterianos/farmacología , Infecciones por Campylobacter/microbiología , Campylobacter jejuni/efectos de los fármacos , Niño , Heces/microbiología , Gastroenteritis/microbiología , Grecia , Hospitalización , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
OBJECTIVE: The epidemiology of Group A Streptococcus (GAS) in Greece is not known. We have therefore conducted this prospective study to investigate the isolation rate of GAS from pediatric specimens, determine T-serotype frequency and examine the susceptibility of GAS to penicillin, erythromycin and clindamycin. METHODS: Over a 3-year study-period (1993-95) 11 597 clinical specimens obtained from sick children were inoculated on appropriate culture media. The isolation and identification of GAS strains were assessed by conventional methods. T-typing was performed by slide agglutination. Serum opacity factor (OF) was detected by microwell METHOD: The susceptibility of the strains was tested by the Kirby Bauer method. RESULTS: GAS were isolated from 1125 out of 11 597 (9.7%) clinical specimens, mostly from throat samples (15.6%). T-serotyping was performed in 652 GAS strains. A significant difference of the incidence of T-serotypes was observed within the 3 years studied (chi2 = 70.3, DF = 18, P < 0.001). The most dominant isolates were T-1 (25%), T-4 (20%) and T-12 (16%) during 1993, 1994 and 1995, respectively. Non-typeable (NT) strains were 4%. OF and hyaluronic acid were produced from 49.8% and 3% of the strains, respectively. All isolated strains were susceptible to penicillin and clindamycin. Resistance to erythromycin was 5.0-8.7% over the 3-year study period. CONCLUSIONS: There was a wide distribution of GAS T-serotypes in Athens and a significant change in their annual predominance. All strains were susceptible to penicillin and clindamycin, but a low level of erythromycin resistance was observed.