Gabriella da Silva Mendes

Antiviral activity of extracts from Brazilian seaweeds against herpes simplex virus

Organic extracts of 36 species of marine algae (sixteen species of Rhodophyta, eight species of Ochrophyta and twelve species of Chlorophyta) from seven locations on the Brazilian coast were evaluated for their anti-HSV-1 and anti-HSV-2 activity resistant to Acyclovir (ACV). Activity tests in crude extracts, followed by the identification of the major compounds present, were performed for all species. The chemical profiles of all crude extracts were obtained by 1H-NMR and 13C-NMR spectroscopy. The percentage of extracts with antiviral activity was higher for HSV-1 (86.1%) than for HSV-2 (55.5%). The green algae Ulva fasciata and Codium decorticatum both showed the highest activity (99.9%) against HSV-1, with triacylglycerols and fatty acids as the major components. The red alga Laurencia dendroidea showed good activity against HSV-1 (97.5%) and the halogenated sesquiterpenes obtusol and (-)-elatol were identified as the major components in the extract. Against HSV-2, the green alga Penicillus capitatus (Chlorophyta) and Stypopodium zonale (Ochrophyta) were the most active (96.0 and 95.8%). Atomaric acid, a meroditerpene, was identified as the major secondary metabolite in the S. zonale extract. These results reinforce the role of seaweeds as important sources of compounds with the potential to enter into the pipeline for development of new drugs against herpes simplex.

In Vitro Anti-HMPV Activity of Meroditerpenoids from Marine Alga Stypopodium zonale (Dictyotales)

In this paper, we evaluated the antiviral activity against HMPV replication of crude extract of the marine algae Stypopodium zonale and of two meroditerpenoids obtained from it, atomaric acid and epitaondiol, and a methyl ester derivative of atomaric acid. Their selectivity indexes were 20.78, >56.81, 49.26 and 12.82, respectively. Compared to ribavirin, the substances showed a relatively low cytotoxicity on LLC-MK2 cells, with a significant antiviral activity, inhibiting at least 90% of viral replication in vitro, which demonstrates the potential of these marine natural products to combat infections caused by HMPV in vitro.

Shedding of Polyomavirus in the Saliva of Immunocompetent Individuals

The aim of this study was to investigate and compare the frequency of BKV, JCV, WUV, and KIV in the saliva of healthy individuals. Samples were analyzed for the presence of polyomaviruses (BKV, JCV, WUV, and KIV) DNA by real‐time PCR. Of the 291 samples tested, 71 (24.3%) were positive for at least one of the screened polyomaviruses. Specifically, 12.7% (37/291) were positive for WUV, 7.2% (21/291) positive for BKV, 2.4% (7/291) positive for KIV, and 0.3% (1/291) positive for JCV. BKV and WUV co‐infections were detected in 1.7% (5/291) of individuals. No other co‐infection combinations were found. The mean number of DNA copies was high, particularly for WUV and BKV, indicating active replication of these viruses. Polyomavirus detection was higher among individuals 15–19 years of age (46.0%; 23/50) and ≥50 years of age (33.3%; 9/27). However, the detection rate in the first group was almost 1.7× greater than the latter. WUV infections were more frequent in individuals between the ages of 15 and 19 years and the incidence decreased with age. By contrast, BKV excretion peaked and persisted during the third decade of life and KIV infections were detected more commonly in subjects ≥50 years old. These findings reinforced the previous hypotheses that saliva may be a route for BKV transmission, and that the oral cavity could be a site of virus replication. These data also demonstrated that JCV, WUV, and KIV may be transmitted in a similar fashion. J. Med. Virol. 85:144–148, 2012.

Antiviral activity of the green marine alga Ulva fasciata on the replication of human metapneumovirus

We evaluated the antiviral activity of the marine alga, Ulva fasciata, collected from Rasa beach and Forno beach, Búzios, Rio de Janeiro, Brazil on the replication of human metapneumovirus (HMPV). The algae extracts were prepared using three different methodologies to compare the activity of different groups of chemical composites obtained through these different methodologies. Four out of the six extracts inhibited nearly 100% of viral replication. The results demonstrated that the majority of the extracts (five out of six) possess virucidal activity and therefore have the ability to interact with the extracellular viral particles and prevent the infection. On the other hand, only two extracts (from Forno beach, obtained by maceration and maceration of the decoction) were able to interact with cell receptors, hindering the viral entry. Finally, only the extract of algae collected at Forno beach, obtained by maceration presented intracellular activity. To our knowledge, this is a pioneer study on antiviral activity of marine algae against HMPV. It is also the first on antiviral activity against HMPV ever done in Brazil. The study also shows the effect of different environment factors and different chemical procedures used to obtain the extract on its biological properties.

Salivirus and aichivirus A infections in children with gastroenteritis in Brazil

Stool samples were obtained from healthy children and children with diarrhoea in Rio de Janeiro, Brazil, and analysed for aichivirus A and salivirus by reverse transcription PCR. Aichivirus A was detected in 5 (0.8%) and salivirus in 10 (1.7%) of the samples obtained from children with diarrhoea. None of the healthy children tested positive for these viruses. The results demonstrate that these viruses continuously circulate in the country, although at a low frequency.

Outbreak of diarrhea among preweaning alpacas (Vicugna pacos) in the southern Peruvian highland

INTRODUCTION Infections, particularly diarrheal infections, are a major cause of neonatal death in South American camelids. The aim of this study was to identify the pathogens that could have caused the recent diarrhea outbreak among the alpacas in Silli, Cusco, located in the southern Peruvian highland. METHODOLOGY Spleen, kidney, and intestine tissue along with fecal and intestinal lavage samples were obtained from 50 one- to five-week-old alpacas and analyzed for the presence of parasites, bacteria, and viruses. RESULTS Laboratory testing of the 50 crias included in this study revealed that 80% were infected with Eimeria spp., 40% with coronavirus, 34% with E. coli, 32% with rotavirus, 22% with Clostridium spp., and 20% with Cryptosporidium spp. Of these 50 alpaca crias, 20 presented with a single infection (19 positive for Eimeria spp. and 1 positive for rotavirus). Co-infections with up to four pathogens occurred in 60% of the samples. The significance of such infections is not clear, but it is noteworthy that the animals suffering from necrotic and/or hemorrhagic enteritis presented with quadruple infections. It is likely that co-infections increase the severity of the disease. CONCLUSIONS These data show that multiple pathogens circulate among young alpaca crias and could be associated with diarrheal disease in these animals. The findings from this study warrant the provision of subsidies for future assessment of the potential economic impact of these infections on the productivity of the Peruvian alpaca industry.

Anti-HSV activity of Hypnea musciformis cultured with different phytohormones

Four extracts from the seaweed Hypnea musciformis (Wulfen in Jacq.) J.V. Lamour. (Rhodophyta), collected directly from its natural habitat or cultivated in the presence of phytohormones, were evaluated for their ability to inhibit the replication of acyclovir-resistant herpes simplex viruses types 1 (HSV-1) and 2 (HSV-2) strains. The main purpose was to determinate whether these growth conditions would affect the antiviral activity. Our results showed the possibility of improving the anti-HSV activity by using extracts from algae cultured in the presence of phytohormones.

Frequency of viral etiology in symptomatic adult upper respiratory tract infections

Abstract Aims To determine the frequency of viral pathogens causing upper respiratory tract infections in non-hospitalized, symptomatic adults in the city of Rio de Janeiro. Methods Respiratory samples (nasal/throat swabs) were collected between August 2010 and November 2012 and real time PCR was used to detect different viral pathogens. Results Viruses were detected in 32.1% (43/134) of samples from 101 patients. Specifically, 9% (12/134) were positive for HBoV, 8.2% (11/134) were positive for HAdV, 5.2% (7/134) were positive for HRV, and 1.5% (2/134) were positive for FLUBV or HMPV, as single infections. HRSV-A, HPIV-3, and HCoV-HKU1 were detected in one (0.75%) sample each. Co-infections were detected in 4.8% (6/134) of the samples. Peaks of viral infections were observed in March, April, May, August, and October. However, positive samples were detected all year round. Only 23.3% (10/43) of the positive samples were collected from patients with febrile illness. Conclusion Results presented in this report suggest that respiratory viral infections are largely under diagnosed in immunocompetent adults. Although the majority of young adult infections are not life-threatening they may impose a significant burden, especially in developing countries since these individuals represent a large fraction of the working force.

Influenza A virus infection of healthy piglets in an abattoir in Brazil: animal-human interface and risk for interspecies transmission

Asymptomatic influenza virus infections in pigs are frequent and the lack of measures for controlling viral spread facilitates the circulation of different virus strains between pigs. The goal of this study was to demonstrate the circulation of influenza A virus strains among asymptomatic piglets in an abattoir in Brazil and discuss the potential public health impacts. Tracheal samples (n = 330) were collected from asymptomatic animals by a veterinarian that also performed visual lung tissue examinations. No slaughtered animals presented with any noticeable macroscopic signs of influenza infection following examination of lung tissues. Samples were then analysed by reverse transcription-polymerase chain reaction that resulted in the identification of 30 (9%) influenza A positive samples. The presence of asymptomatic pig infections suggested that these animals could facilitate virus dissemination and act as a source of infection for the herd, thereby enabling the emergence of influenza outbreaks associated with significant economic losses. Furthermore, the continuous exposure of the farm and abattoir workers to the virus increases the risk for interspecies transmission. Monitoring measures of swine influenza virus infections and vaccination and monitoring of employees for influenza infection should also be considered. In addition regulatory agencies should consider the public health ramifications regarding the potential zoonotic viral transmission between humans and pigs.

Human polyomavirus KI, WU, BK, and JC in healthy volunteers

Despite the growing importance of infections caused by the human polyomaviruses (HPyVs), information about their transmission, pathogenesis, and epidemiology is scarce. The objective of this work was to evaluate the excretion and distribution of HPyV (HPyV1-HPyV4 [former BKPyV, JCPyV, KIPyV, and WUPyV, respectively]) among asymptomatic individuals from different geographic regions in Brazil, in order to verify the existence of distinct epidemiologic patterns among the Brazilian population. Saliva samples from 889 healthy volunteers living in nine locations in Brazil were analyzed by real-time polymerase chain reaction (PCR) to detect HPyV1–4. Among 889 participants, 346 (39%) had evidence of infection with one or more HPyV species: 127 (14.3%) had HPyV1 only; 70 (7.9%) had HPyV3 only; 60 (6.7%) had HPyV4 only, and 25 (2.8%) had HPyV2 only. Coinfections were detected in 64 participants (7.3%). Although HPyV excretion was detected in samples from all locations, the frequency and distribution of viral species varied significantly. The epidemiologic findings presented demonstrate that the four HPyV species studied are circulating in five geographic regions of Brazil. Salivary excretion of these viruses appears common among healthy Brazilians. The distribution of viral species varies considerably between regions as well as within regions.