1,721,044 research outputs found
Diagnostica delle gastroenteriti virali
No full textVengono illustrati gli agenti eziologici principali della gastroenteriti virali (rotavirus, norovirus, adenovirus, astrovirus), le loro caratteristiche epidemiologiche e i metodi diagnostic
Funghi e virus nelle infezioni miste: storie di sinergie e di contrasti
No full textI casi clinici di infezioni polimicrobiche riportati in letteratura sono in continuo aumento, da un lato per il sempre più alto numero di individui suscettibili, dall’altro per il significativo incremento nella sensibilità delle tecniche di indagine, che consentono di diagnosticare casi prima non rilevabili. Gli eventi biomolecolari che caratterizzano l’interazione patogeno-patogeno, consentendo l’instaurarsi di una infezione mista ed eventualmente influenzando il suo decorso, rimangono scarsamente studiati, soprattutto quando sono coinvolti microrganismi filogeneticamente distanti. Il macrofago ha un ruolo fondamentale nella difesa contro i microrganismi, sia come effettore antimicrobico diretto, sia come elemento in grado di polarizzare la risposta immunitaria adattativa. I meccanismi che stanno alla base della reattività macrofagica nel corso di infezioni singole sono stati oggetto di studi approfonditi; diversamente, le possibili conseguenze di un’infezione mista sul macrofago e le eventuali interazioni, sinergistiche o antagonistiche, tra patogeni notoriamente macrofagotropi costituiscono un campo di indagine ancora scarsamente esplorato. Da alcuni anni, il nostro gruppo di ricerca indaga questo aspetto, con l’obiettivo di meglio comprendere i meccanismi che controllano la patogenesi delle infezioni miste da miceti e virus e la concomitante immunoreattività dell’ospite. In particolare, è stato messo a punto ed impiegato un modello in vitro di infezione doppia in cui macrofagi umani sono stati dapprima esposti ad un Herpesvirus (Herpes Simplex Virus-1, virus di Epstein-Barr, Herpesvirus Umano-6) e poi infettati con funghi opportunisti patogeni (Cryptococcus neoformans oppure Candida albicans). Successivamente, i macrofagi così trattati sono stati valutati per reattività antifungina, in termini di fagocitosi, killing microbico e pattern di secrezione, così come per espressione di molecole di superficie e per profilo d’espressione genica. I dati ottenuti finora dimostrano una profonda alterazione dell’immunoreattività macrofagica in risposta all’infezione da Herpesvirus, con un aumento della fagocitosi associato ad una diminuzione del killing verso il fungo. Anche l’espressione genica e i dati relativi al pattern di secrezione citochinica e delle molecole di superficie indicano una condizione di iporesponsività da parte del macrofago esposto ad Herpesvirus. Questi dati in vitro dimostrano un’interazione sinergica tra patogeni a svantaggio dell’ospite, suggerendo che nel paziente un’infezione erpetica attiva possa rappresentare un ulteriore fattore di rischio nei riguardi delle micosi opportunistiche
Viruses and Multiple Sclerosis
No full textMultiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system whose cause is still unknown. Many findings suggest an infectious etiology or, at least, that infectious agents in association with host genetic factors may play a role in the pathogenesis of this disease. Accumulating data, including animal models, human models of virus induced demyelination, epidemiologic, and laboratory findings, demonstrate that viruses and host genetic factors can interact to cause immune-mediated demyelination. While many viruses have been postulated as a possible cause of MS, to date, no "MS virus" has been definitively shown to be associated with this disease. Alternatively, ubiquitous viruses are being considered as the environmental "triggers" that have been postulated to be involved in the MS disease process. We will focus on recent studies with human herpesvirus 6 and MS as how a common virus may be associated with this disorder in a subset of infected individuals
Synthesis and antiviral activity of new benzothiadiazine dioxide derivates
No full textIn continuing our search in the benzothiadiazine field, we have synthesized new alkylated 2,1,3-BTD and 1,2,4-BTD derivatives. The procedure of alkylation is led via Mitsunobu reaction with good yields. The compounds were tested for their antiviral activity versus some viral strain (ADV, HHV-6, Cox-B5 and H-CMV) and most of them are resulted active at micromolar level. Except compound 1a that presents a high cytotoxicity (maximum non toxic concentration was 3μM), all the other molecules prepared are poorly cytotoxic (maximum non toxic concentrations were >25μM)
“Microbiologia medica” Volume 3 della nuova edizione italiana sulla settima edizione di Prescott, Harley and Klein’s “Microbiology” .
No full textManuale di Microbiologia medic
Evaluation of a vero cell toxicity test to detect EHEC infection
No full textAn epidemiologic investigation was carried out in Modena (Italy) to evaluate the prevalence of faecal VEROtoxin (FVT) in diarrhoeal stool specimens. One thousand and sixty-six stool specimens, submitted to the Clinical Microbiology Laboratory of the University Hospital of Modena, were collected and faecal filtrates tested for neutralizable cytotoxin by a toxicity test on VERO cells. Cytopathic effect on VERO cells was produced by 301 stool specimens (28%); neutralizable VT was detected in 40 (13%) out of 301 positive samples (3.7% of 1066 specimens). The prevalent FVT type was VT2 (50%), followed by VT1 (32.5%) and VT1+2 (17.5%). We evaluated an assay that detects both VTs directly from stool specimens to demonstrate that enterohemorrhagic strains (EHEC) should be considerated a causative agent of sporadic non-bloody diarrhoea. Our results suggest that toxin neutralization assay is a sensitive and specific technique and may be used as an alternative method to diagnose diarrhoeal infections caused by EHEC
Relation between psychoneuroendocrine profile in stressful conditions and antibodies to herpesvirus 6 and 7
No full textThe aim of the present study is to evaluate whether the individual susceptibility to infectious disease is influenced by the psychological profile of cadets exposed to stressful events associated with military lifestyle in academy and if the neuroendocrine responses to stressful events is related with humoral immunity estimated by measuring antibody titres to human herpesvirus (HHV-6)7 (HHV-7) and to what extent it is influenced by personality traits. It has been observed that cadets with lower psychoaptitude scores (1-2) have a significant higher susceptibility to infectious disease (x2=7.95; p=0.019) compared to subjects with higher scores. A positive relationship between cortisol and antibody titers to HHV-6 (r=0.304; p=0.024) it has been found. It can be interesting to observe that antibody titers on HHV-6 are also related to psychoaptitude profile (r=0.239; p=0.044). The antibody titers to HHV-7 are negatively related to the 5 scales of BFQ and in particular with subdimension Co (cordiality) of BFQ (r=0.401; p=0.002). The survey carried out on over 1,500 cadets of the Military Academy of Modena shows that the susceptibility to infectious diseases during the first six months of admission to the Academy seem to be influenced by the psychoaptitudinal profile. The finding of a positive relationship between serum cortisol and antibody vs HHV-6 suggests that the impairment of the immune system linked to circulatory cortisol levels may induce a reactivation of a latent herpesvirus 6 with related increase of antibody titers
Screening of the antibacterial effects of a variety of essential oils on the microrganims responsible for respiratory infections
No full textThe aim of this study was to examine the cytotoxicity and the antibacterial effects of a variety of essential oils on major respiratory tract pathogens. The cytotoxicity of 13 essential oils was evaluated on Vero cells. The antibacterial activity was evaluated by the Kirby Bauer paper method, minimum inhibitory and bactericidal concentration against Streptococcus pyogenes, agalactiae, pneumoniae and Klebsiella pneumoniae, Haemophilus influenzae, Staphylococcus aureus and Stenotrophomonas maltophilia isolated from clinical specimens. The antibiotic sensitivity of these isolates was examined. Some oils showed inhibition of bacterial growth against most of the organisms examined. Cinnamon and thyme showed the strongest action followed by clove. The results reported in this paper indicate that thyme can be considered as a potential antimicrobial agent for the treatment of some respiratory tract infections in man
EFFECT OF EUCALYPTUS ESSENTIAL OIL ON RESPIRATORY BACTERIA AND VIRUSES
No full textThe activity of Eucalyptus globulus essentialoil was determined for 120 isolates of Streptococcus pyogenes,20 isolates of S. pneumoniae, 40 isolates of S.agalactiae, 20 isolates of Staphylococcus aureus, 40 isolatesof Haemophilus influenzae, 30 isolates of H.parainfluenzae, 10 isolates of Klebsiella pneumoniae, 10isolates of Stenotrophomonas maltophilia and two viruses,a strain of adenovirus and a strain of mumps virus, allobtained from clinical specimens of patients with respiratorytract infections. The cytotoxicity was evaluated onVERO cells by the MTT test. The antibacterial activity wasevaluated by the Kirby Bauer paper method, minimuminhibitory concentration, and minimum bactericidal concentration.H. influenzae, parainfluenzae, and S.maltophilia were the most susceptible, followed by S.pneumoniae. The antiviral activity, assessed by means ofvirus yield experiments titered by the end-point dilutionmethod for adenovirus, and by plaque reduction assay formumps virus, disclosed only a mild activity on mumpsvirus
HSV-1 induces macrophage activation and dysregulation in monocytes
No full textClinical cases of double infections by fungi and viruses are increasing, especially in immunocompromised hosts. To date, the biomolecular events that characterize the outcome of polymicrobic diseases remain poorly investigated and little is known on the mutual interactions occurring between pathogens. In order to investigate the interplay between microrganisms co-infecting macrophagic cells, we recently set up an in vitro model in which a monocytic cell line was infected with human herpesvirus 6 and C. neoformans. In the present work, we used an similar model to understand the molecular mechanisms underlying interactions between herpes simplex virus 1 (HSV-1) and C. albicans. The monocytic cell line THP-1 was infected with HSV-1 and, after an overnight incubation, cells were exposed to C. albicans. The cell response to the viral infection was evaluated as phagocytosis of C. albicans and killing of the ingested fungus. Moreover, a number of activation markers (CD38, CD69, CD95) and adhesion molecules (CD54, TLR-2, CD11b, CD106) was evaluated by FACS analysis in THP-1 cells. THP-1 cells infected with HSV-1 showed increased phagocytosis of C. albicans but reduced killing capability, suggesting that in the course of a double infection macrophages could contribute to yeast dissemination. Activation markers (CD38 and CD69) were found down expressed by FACS analysis in HSV-1-infected THP-1 cells, accounting for the failure in the antifungal activity
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