Maria São José Nascimento

Surveillance of adenoviruses and noroviruses in European recreational waters

Abstract Exposure to human pathogenic viruses in recreational waters has been shown to cause disease outbreaks. In the context of Article 14 of the revised European Bathing Waters Directive 2006/7/EC (rBWD, CEU, 2006) a Europe-wide surveillance study was carried out to determine the frequency of occurrence of two human enteric viruses in recreational waters. Adenoviruses were selected based on their near-universal shedding and environmental survival, and noroviruses (NoV) selected as being the most prevalent gastroenteritis agent worldwide. Concentration of marine and freshwater samples was done by adsorption/elution followed by molecular detection by (RT)-PCR. Out of 1410 samples, 553 (39.2%) were positive for one or more of the target viruses. Adenoviruses, detected in 36.4% of samples, were more prevalent than noroviruses (9.4%), with 3.5% GI and 6.2% GII, some samples being positive for both GI and GII. Of 513 human adenovirus-positive samples, 63 (12.3%) were also norovirus-positive, whereas 69 (7.7%) norovirus-positive samples were adenovirus-negative. More freshwater samples than marine water samples were virus-positive. Out of a small selection of samples tested for adenovirus infectivity, approximately one-quarter were positive. Sixty percent of 132 nested-PCR adenovirus-positive samples analysed by quantitative PCR gave a mean value of over 3000 genome copies per L of water. The simultaneous detection of infectious adenovirus and of adenovirus and NoV by (RT)PCR suggests that the presence of infectious viruses in recreational waters may constitute a public health risk upon exposure. These studies support the case for considering adenoviruses as an indicator of bathing water quality.

Virus hazards from food, water and other contaminated environments

Abstract Numerous viruses of human or animal origin can spread in the environment and infect people via water and food, mostly through ingestion and occasionally through skin contact. These viruses are released into the environment by various routes including water run‐offs and aerosols. Furthermore, zoonotic viruses may infect humans exposed to contaminated surface waters. Foodstuffs of animal origin can be contaminated, and their consumption may cause human infection if the viruses are not inactivated during food processing. Molecular epidemiology and surveillance of environmental samples are necessary to elucidate the public health hazards associated with exposure to environmental viruses. Whereas monitoring of viral nucleic acids by PCR methods is relatively straightforward and well documented, detection of infectious virus particles is technically more demanding and not always possible (e.g. human norovirus or hepatitis E virus). The human pathogenic viruses that are most relevant in this context are nonenveloped and belong to the families of the C aliciviridae, A denoviridae, H epeviridae, P icornaviridae and R eoviridae. Sampling methods and strategies, first‐choice detection methods and evaluation criteria are reviewed.

Xanthones as inhibitors of growth of human cancer cell lines and Their effects on the proliferation of human lymphocytes In Vitro

Twenty-seven oxygenated xanthones have been assessed for their capacity to inhibit in vitro the growth of three human cancer cell lines, MCF-7 (breast cancer), TK-10 (renal cancer) and UACC-62 (melanoma). The effect of these xanthones on the proliferation of human T-lymphocytes was also evaluated. Differences on their potency towards the effect on the growth of the human cancer cell lines as well as on the proliferation of human T-lymphocytes can be ascribed to the nature and positions of the substituents on the xanthonic nucleus.

Novel Norovirus in Dogs with Diarrhea

To identify the prevalence and genetic variability of noroviruses in dogs, we tested fecal samples by using reverse transcription–PCR. We found canine norovirus in 40% and 9% of dogs with and without diarrhea, respectively. The virus was genetically unrelated to other noroviruses and constitutes a tentative new genogroup.

Catechols from abietic acid synthesis and evaluation as bioactive compounds.

Catechols from abietic acid were prepared by a short and good yielding chemical process and further evaluated for several biological activities namely, antifungal, antitumoral, antimutagenic, antiviral, antiproliferative and inhibition of nitric oxide. Their properties were compared with those of carnosic acid (6), a naturally occurring catechol with an abietane skeleton and known to possess potent antioxidant activity, as well as anticancer and antiviral properties. From all the synthetic catechols tested compound 2 showed the best activities, stronger than carnosic acid.

Favipiravir (T-705) inhibits in vitro norovirus replication

Human noroviruses are the primary cause of foodborne gastroenteritis. Potent and safe inhibitors are needed for the treatment/prophylaxis of norovirus infections. We demonstrate that Favipiravir [T-705, a drug in advanced clinical development for the treatment of infections with the influenza virus] inhibits in vitro murine norovirus replication. Time-of-drug addition studies reveal that T-705 exerts its activity at a time-point that coincides with onset of viral RNA synthesis, which is in line with the viral polymerase as the presumed target.

The Viral Polymerase Inhibitor 2′-C-Methylcytidine Inhibits Norwalk Virus Replication and Protects against Norovirus-Induced Diarrhea and Mortality in a Mouse Model

ABSTRACT Human noroviruses are a major cause of food-borne illness, accountable for 50% of all-etiologies outbreaks of acute gastroenteritis (in both developing and developed countries). There is no vaccine or antiviral drug for the prophylaxis or treatment of norovirus-induced gastroenteritis. We recently reported the inhibitory effect of 2′-C-methylcytidine (2CMC), a hepatitis C virus polymerase inhibitor, on the in vitro replication of murine norovirus (MNV). Here we evaluated the inhibitory effect of 2CMC on in vitro human norovirus replication through a Norwalk virus replicon model and in a mouse model by using AG129 mice orally infected with MNV. Survival, weight, and fecal consistency were monitored, and viral loads in stool samples and organs were quantified. Intestines were examined histologically. 2CMC reduced Norwalk virus replicon replication in a dose-dependent manner and was able to clear cells of the replicon. Treatment of MNV-infected AG129 mice with 2CMC (i) prevented norovirus-induced diarrhea; (ii) markedly delayed the appearance of viral RNA and reduced viral RNA titers in the intestine, mesenteric lymph nodes, spleen, lungs, and stool; (iii) completely prevented virus-induced mortality; and (iv) resulted in protective immunity against a rechallenge. We demonstrate for the first time that a small-molecule inhibitor of norovirus replication protects from virus-induced disease and mortality in a relevant animal model. These findings pave the way for the development of potent and safe antivirals as prophylaxis and therapy of norovirus infection.

Prenylated derivatives of baicalein and 3,7-dihydroxyflavone: Synthesis and study of their effects on tumor cell lines growth, cell cycle and apoptosis

Fourteen baicalein and 3,7-dihydroxyflavone derivatives were synthesized and evaluated for their inhibitory activity against the in vitro growth of three human tumor cell lines. The synthetic approaches were based on the reaction with prenyl or geranyl bromide in alkaline medium, followed by cyclization of the respective monoprenylated derivative. Dihydropyranoflavonoids were also obtained by one-pot synthesis, using Montmorillonite K10 clay as catalyst combined with microwave irradiation. In vitro screening of the compounds for cell growth inhibitory activity revealed that the presence of one geranyl group was associated with a remarkable increase in the inhibitory activity. Moreover, for the 3,7-dihydroxyflavone derivatives a marked increase in growth inhibitory effect was also observed for compounds with furan and pyran fused rings. The most active compounds were also studied regarding their effect on cell cycle profile and induction of apoptosis. Overall the results point to the relevant role of the prenylation of flavone scaffold in the growth inhibitory activity of cancer cells.

Outbreak of Porcine Epidemic Diarrhea Virus in Portugal, 2015

Summary An outbreak of porcine epidemic diarrhea virus (PEDV) in the South of Portugal in January 2015 and the spread of PEDV northwards in the territory are described. Comparative analysis of the amplified sequences showed a very high (99.0%) identity with the PEDV variant most recently reported in the United States and also show complete (100%) identity to the strains recently reported in Germany, supporting the hypothesis that a unique strain is currently circulating in Europe. The origin of this PEDV variant still needs to be elucidated and further studies in the remaining European countries may contribute to the knowledge.

Presence of Antibodies against Genogroup VI Norovirus in Humans

BackgroundNoroviruses are important enteric pathogens in humans and animals. Recently, we reported a novel canine norovirus (CaNoV) in dogs with diarrhea belonging to a new genogroup (GVI). No data are available on exposure of humans to this virus.MethodsSera from 373 small animal veterinarians and 120 age-matched population controls were tested for IgG antibodies to CaNoV by a recombinant virus like particle based enzyme-linked immunosorbent assay.ResultsAntibodies to CaNoV were found in 22.3% of the veterinarians and 5.8% of the control group (p < 0.001). Mean corrected OD450 values for CaNoV antibodies were significantly higher in small animal veterinarians compared to the control group.ConclusionsThese findings suggest that CaNoV may infect humans and small animal veterinarians are at an increased risk for exposure to this virus. Additional studies are needed to assess if this virus is able to cause disease in humans.