447 research outputs found
Use Of Molecular Epidemiology To Monitor The Nosocomial Dissemination Of Methicillin-resistant Staphylococcus Aureus In A University Hospital From 1991 To 2001.
Methicillin-resistant Staphylococcus aureus (MRSA) has been the cause of major outbreaks and epidemics among hospitalized patients, with high mortality and morbidity rates. We studied the genomic diversity of MRSA strains isolated from patients with nosocomial infection in a University Hospital from 1991 to 2001. The study consisted of two periods: period I, from 1991 to 1993 and period II from 1995 to 2001. DNA was typed by pulsed-field gel electrophoresis and the similarity among the MRSA strains was determined by cluster analysis. During period I, 73 strains presented five distinctive DNA profiles: A, B, C, D, and E. Profile A was the most frequent DNA pattern and was identified in 55 (75.3%) strains; three closely related and four possibly related profiles were also identified. During period II, 80 (68.8%) of 117 strains showed the same endemic profile A identified during period I, 18 (13.7%) closely related profiles and 18 (13.7%) possibly related profiles and, only one strain presented an unrelated profile. Cluster analysis showed a 96% coefficient of similarity between profile A from period I and profile A from period II, which were considered to be from the same clone. The molecular monitoring of MRSA strains permitted the determination of the clonal dissemination and the maintenance of a dominant endemic strain during a 10-year period and the presence of closely and possibly related patterns for endemic profile A. However, further studies are necessary to improve the understanding of the dissemination of the endemic profile in this hospital.371345-5
Yeasts and moulds contaminants of food ice cubes and their survival in different drinks
Aims: To evaluate the levels of unicellular and filamentous fungi in ice cubes produced at different levels and to determine their survival in alcoholic beverages and soft drinks. Methods and Results: Sixty samples of ice cubes collected from home level (HL) productions, bars and pubs (BP) and industrial manufacturing plants (MP) were investigated for the presence and cell density of yeasts and moulds. Moulds were detected in almost all samples, while yeasts developed from the majority of HL and MP samples. Representative colonies of microfungi were subjected to phenotypic and genotypic characterization. The identification was carried out by restriction fragment length polymorphism (RFLP) analysis of the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5·8S rRNA gene. The process of yeast identification was concluded by sequencing the D1/D2 region of the 26S rRNA gene. The fungal biodiversity associated with food ice was represented by nine yeast and nine mould species. Strains belonging to Candida parapsilosis and Cryptococcus curvatus, both opportunistic human pathogens, and Penicillium glabrum, an ubiquitous mould in the ice samples analysed, were selected to evaluate the effectiveness of the ice cubes to transfer pathogenic microfungi to consumers, after addition to alcoholic beverages and soft drinks. All strains retained their viability. Conclusions: The survival test indicated that the most common mode of consumption of ice cubes, through its direct addition to drinks and beverages, did not reduce the viability of microfungi. Significance and Impact of the Study: This study evidenced the presence of microfungi in food ice and ascertained their survival in soft drinks and alcoholic beverages
Gold-Silver Catalysts: Ruling Factors for Establishing Synergism
DPU and SOL immobilisation have been used to prepare 1 %AuAg/TiO2 with internal ratio 1 : 1 and 4 : 1 which have been studied as fresh, calcined in air at 300 \ub0C and reduced at 550 \ub0C in H2. TEM-EDS, XPS, UV-Vis and CO-DRIFT allowed to characterize the samples in terms of particle size, particle composition, exposure and oxidation state of metals. Correlating these characteristics to the catalytic behaviour we concluded that only Au-rich catalysts show synergistic effect, silver in bimetallic systems appears more resistant to oxidation than in monometallic one, thermal treatment enhances the SMSI thus producing (regardless to the post-treatment) almost the same amount of Au\u3b4+ and also Ag\u3b4+. Catalysts prepared by DPU (calcined in air or reduced in H2) are more active than SOL (fresh or calcined) probably due to the higher presence of gold at the surface
Treatment of Hepatitis C virus genotype 3 infection with direct-acting antiviral agents
Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of directacting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83-100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contra-indications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82-96% among patients without cirrhosis and 62-92% among those with cirrhosis. Finally, SOF plus DCV provides 94-97% SVR rates in non-cirrhotic patients, but 59-69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection491
Gli effetti dell’introduzione della nuova mappa di pericolosità sulla valutazione del rischio sismico in Italia.
L’introduzione di una versione aggiornata della mappa di pericolosità sismica, definita per diversi periodi di ritorno e per svariati valori di ordinate spettrali, porta inevitabilmente a dei cambiamenti sul livello di rischio sismico del costruito italiano. Poiché la relazione tra domanda e capacità non è lineare per tutto il range di periodi
di vibrazione strutturale, è necessario valutare il cambiamento del livello di rischio sismico calcolando esplicitamente la vulnerabilità sismica di strutture esistenti con diversi periodi di vibrazione, per diversi stati limite e considerando sia la nuova che la precedente definizione di pericolosità . Nel presente lavoro è stato
eseguito un primo studio degli effetti che l’introduzione di mappe aggiornate della pericolosità sismica potrebbe avere sulla valutazione dei livelli di rischio sismico nel territorio italiano. Le caratteristiche generali del costruito sono state ricavate dai dati del 14° Censimento Generale della Popolazione e delle Abitazioni (ISTAT
2001), mentre una procedura probabilistica di valutazione sismica per edifici esistenti a scala urbana è stata impiegata per stimare la capacità . Sono stati considerati tutti i tre stati limite prescritti dall’Ordinanza
(danno lieve, danno severo, collasso) in corrispondenza dei rispettivi valori di domanda, così come il cambiamento delle forme spettrali in funzione della localizzazione e del periodo di ritorno. I risultati dimostrano che la nuova mappa di pericolosità sismica porta a dei livelli di rischio sismico più realistici e meno allarmanti,
rendendo leggermente meno gravoso, anche se non privo di problematiche, il panorama attuale di rischio in Italia
DBMI04, il database delle osservazioni macrosismiche dei terremoti italiani utilizzate per la compilazione del catalogo parametrico CPTI04
This paper describes the main features of the Macroseismic Database of Italy 2004, which for the first time put together in a critical way the macroseismic data used for the compilation of the CPTI04 (2004) parametric earthquake catalogue. Data come from varied main datasets: i) DOM4.1 (Monachesi e Stucchi, 1997); ii) CFTI version 2 (Boschi et al., 1997) and, for the time-window 1980-2002, CFTI version 3 (Boschi et al., 2000); iii) Bollettino Macrosismico ING (BMING); iv) Catalogo Macrosismico dei Terremoti Etnei, Azzaro et al. (2000; 2002). In addition, data from recent historical and field investigation were also used. DBMI04 contains 58146 macroseismic observations related to 1041 earthquakes and 14161 localities, 12943 of which in Italy. The input data used for the compilation of DBMI04 were not homogeneous with respect to the use of the intensity scale and, mainly, to geographical reference. One of the main task was the organisation of a reliable geographical reference, based on the previous ENEL-ISTAT catalogue of the Italian localities (ENEL, 1978), which was updated by means of new data. Another task consisted in correcting some mistakes performed when associating the placenames quoted by the historical sources and the geographical reference. Some problems were solved using ad hoc conventions for dealing with observations not expressed in terms of macroseismic intensity. This paper presents the adopted solutions and the results, together with the web-interface through which the database is made available to the public (http://emidius.mi.ingv.it/DBMI04/)
A Clinical, Epidemological, Laboratorial, Histological And Ultrasonographical Evaluation Of Anti-hcv Eia-2 Positive Blood Donors.
Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary immunoblot test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83. 5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.42147-5
Clonal Dissemination Of Vana-type Glycopeptide-resistant Enterococcus Faecalis Between Hospitals Of Two Cities Located 100 Km Apart.
Nosocomial dissemination of glycopeptide-resistant enterococci represents a major problem in hospitals worldwide. In Brazil, the dissemination among hospitals in the city of São Paulo of polyclonal DNA profiles was previously described for vancomycin-resistant Enterococcus faecium. We describe here the dissemination of VanA phenotype E. faecalis between two hospitals located in different cities in the State of São Paulo. The index outbreak occurred in a tertiary care university hospital (HCUSP) in the city of São Paulo and three years later a cluster caused by the same strain was recognized in two patients hospitalized in a private tertiary care hospital (CMC) located 100 km away in the interior of the state. From May to July 1999, 10 strains of vancomycin-resistant E. faecalis were isolated from 10 patients hospitalized in the HCUSP. The DNA genotyping using pulsed-field gel electrophoresis (PFGE) showed that all isolates were originated from the same clone, suggesting nosocomial dissemination. From May to July 2002, three strains of vancomycin-resistant E. faecalis were isolated from two patients hospitalized in CMC and both patients were colonized by the vancomycin-resistant Enterococcus in skin lesions. All isolates from CMC and HCUSP were highly resistant to vancomycin and teicoplanin. The three strains from CMC had minimum inhibitory concentration >256 micro g/ml for vancomycin, and 64 (CMC 1 and CMC 2) and 96 micro g/ml (CMC 3) for teicoplanin, characterizing a profile of VanA resistance to glycopeptides. All strains had the presence of the transposon Tn1546 detected by PCR and were closely related when typed by PFGE. The dissemination of the E. faecalis VanA phenotype among hospitals located in different cities is of great concern because E. faecalis commonly colonizes the gastrointestinal tract of patients and healthy persons for periods varying from weeks to years, which, together with the persistence of vancomycin-resistant Enterococcus in hospital rooms after standard cleaning procedures, increases the risk of the dissemination and reservoir of the bacteria.371339-4
Transient elastography and APRI score: looking at false positives and false negatives. Diagnostic performance and association to fibrosis staging in chronic hepatitis C
Although long regarded as the gold standard for liver fibrosis staging in chronic hepatitis C (CHC), liver biopsy (LB) implies both the risk of an invasive procedure and significant variability. The aim of this study was to evaluate the diagnostic performance for transient elastography (TE) and aspartate aminotransferase to platelet index (APRI) used alone and in combination compared to liver biopsy and to analyze false positive/negative results. Patients with CHC, and no previous clinical diagnosis of cirrhosis were enrolled to undergo liver biopsy, TE and APRI. A total of 182 adult patients with a median age of 55 years and median body mass index of 26.71 kg/m2 were analyzed. On LB, 56% of patients had significant levels of fibrosis (METAVIR F≥2) and 28% had advanced fibrosis (F3/F4). The strongest performance for both tests was observed for exclusion of advanced fibrosis with good negative predictive values (89 and 86%, respectively). Low necroinflammatory activity on LB was associated with false negative TE. False positives were associated with NASH and smaller LB fragments. Correlation between APRI and Fibroscan for F≥2 was 100% and 84% for F≥3 and remained high in both false negative and false positive instances, correctly identifying F<2 in 71% of cases and F<3 in 78% (and potentially foregoing up to 84% of LB). We concluded that low individual performance indicators could be attributable to limitations of LB. Poorer differentiation of lower levels of fibrosis is a known issue for LB and remains so for noninvasive tests. Good predictability is possible, however, for advanced fibrosis4991
Exploring the Chemical Space of Macro- and Micro-Algae Using Comparative Metabolomics
With more than 156,000 described species, eukaryotic algae (both macro- and micro-algae) are a rich source of biological diversity, however their chemical diversity remains largely unexplored. Specialised metabolites with promising biological activities have been widely reported for seaweeds, and more recently extracts from microalgae have exhibited activity in anticancer, antimicrobial, and antioxidant screens. However, we are still missing critical information on the distinction of chemical profiles between macro- and microalgae, as well as the chemical space these metabolites cover. This study has used an untargeted comparative metabolomics approach to explore the chemical diversity of seven seaweeds and 36 microalgal strains. A total of 1390 liquid chromatography-mass spectrometry (LC-MS) features were detected, representing small organic algal metabolites, with no overlap between the seaweeds and microalgae. An in-depth analysis of four Dunaliella tertiolecta strains shows that environmental factors may play a larger role than phylogeny when classifying their metabolomic profile
- …