Viability of human adenovirus from hospital fomites.

The monitoring of environmental microbial contamination in healthcare facilities may be a valuable tool to determine pathogens transmission in those settings; however, such procedure is limited to bacterial indicators. Viruses are found commonly in those environments and are rarely used for these procedures. The aim of this study was to assess distribution and viability of a human DNA virus on fomites in an Adult Intensive Care Unit of a private hospital in Rio de Janeiro, Brazil. Human adenoviruses (HAdV) were investigated in 141 fomites by scraping the surface area and screening by quantitative PCR (qPCR) using TaqMan® System (Carlsbad, CA). Ten positive samples were selected for virus isolation in A549 and/or HEp2c cell lines. A total of 63 samples (44.7%) were positive and presented viral load ranging from 2.48 × 10(1) to 2.1 × 10(3) genomic copies per millilitre (gc/ml). The viability was demonstrated by integrated cell culture/nested-PCR in 5 out of 10 samples. Nucleotide sequencing confirmed all samples as HAdV and characterized one of them as specie B, serotype 3 (HAdV-3). The results indicate the risk of nosocomial transmission via contaminated fomites and point out the use of HAdV as biomarkers of environmental contamination.

Evaluation of skimmed milk flocculation method for virus recovery from tomatoes.

This study aimed to evaluate the elution-concentration methodology based on skimmed milk flocculation from three varieties of tomatoes (Solanum lycopersicum L. [globe], Solanum lycopersicum var. cerasiforme [cherry] and hybrid cocktail [grape tomato]) for further monitoring of field samples. Spiking experiments were performed to determine the success rate and efficiency recovery of human norovirus (NoV) genogroup II, norovirus murine-1 (MNV-1) used as sample process control virus and human adenovirus (HAdV). Mean values of 18.8%, 2.8% and 44.0% were observed for NoV GII, MNV-1 and HAdV, respectively with differences according to the types of tomatoes, with lower efficiency for cherry tomatoes. Analysis of 90 samples, obtained at commercial establishments in the metropolitan region of Rio de Janeiro State, revealed 4.5% positivity for HAdV. Bacterial analysis was also performed with no detection of Salmonella spp., L. monocytogenes and fecal coliforms. Data demonstrated that the skimmed milk flocculation method is suitable for recovering HAdV from tomatoes and highlights the need for considering investigation in order to improve food safety.

Cynomolgus Monkeys (Macaca fascicularis) as an Experimental Infection Model for Human Group A Rotavirus.

Group A rotaviruses (RVA) are one of the most common causes of severe acute gastroenteritis in infants worldwide. Rotaviruses spread from person to person, mainly by faecal⁻oral transmission. Almost all unvaccinated children may become infected with RVA in the first two years of life. The establishment of an experimental monkey model with RVA is important to evaluate new therapeutic approaches. In this study, we demonstrated viral shedding and viraemia in juvenile⁻adult Macaca fascicularis orally inoculated with Wa RVA prototype. Nine monkeys were inoculated orally: seven animals with human RVA and two control animals with saline solution. During the study, the monkeys were clinically monitored, and faeces and blood samples were tested for RVA infection. In general, the inoculated animals developed an oligosymptomatic infection pattern. The main clinical symptoms observed were diarrhoea in two monkeys for three days, associated with a reduction in plasmatic potassium content. Viral RNA was detected in seven faecal and five sera samples from inoculated animals, suggesting virus replication. Cynomolgus monkeys are susceptible hosts for human Wa RVA infection. When inoculated orally, they presented self-limited diarrhoea associated with presence of RVA infectious particles in faeces. Thus, cynomolgus monkeys may be useful as animal models to evaluate the efficacy of new antiviral approaches.

Dissemination of human adenoviruses and rotavirus species A on fomites of hospital pediatric units.

Rotavirus A and human adenovirus dissemination were demonstrated both in a pediatric ward and in a neonatal intensive care unit (NICU) of the same pediatric hospital. Virus detection from fomites samples were higher in the pediatric ward (42.3% [137 out of 324]) than in the NICU (4.5% [7 out of 156]), revealing that cleaning processes used in our NICU are effective in reducing viral contamination, suggesting human adenovirus as a potential biomarker of contamination of hospital fomites.

Virus recovering from strawberries: Evaluation of a skimmed milk organic flocculation method for assessment of microbiological contamination.

Skimmed milk organic flocculation method was adapted, optimized and compared with polyethylene glycol (PEG) precipitation and filtration methods for recovering viruses from a strawberry matrix. Spiking experiments with norovirus genogroup II genotype 4 (NoV GII.4) and murine norovirus 1 (MNV-1) demonstrated that the organic flocculation method associated with a glycine elution buffer, filter bag and cetyltrimethylammonium bromide (CTAB) showed a recovery percentage of 2.5 and 32 times higher than PEG precipitation and filtration methodologies for NoV recovering. Furthermore, this method was used for investigating NoV and human adenoviruses (HAdVs) in 90 samples of fresh strawberries commercialized in Rio de Janeiro markets. NoV GI and GII were not detected in those samples and MNV-1, used as internal process control (IPC), was recovered in 95.5% (86) of them. HAdVs were detected in 18 (20.0%) samples and characterized by nucleotide sequencing as Human Mastadenovirus specie F and as type specie HAdV-2. Bacterial analysis did not detect Salmonella spp. and Listeria monocytogenes, however, 3.3% of fecal coliforms were detected in those samples. These results indicate the organic flocculation method as an alternative for recovering enteric viruses from strawberries, emphasizing a need for virus surveillance in food matrices.

Evaluation of skimmed milk flocculation method for virus recovery from tomatoes

Abstract This study aimed to evaluate the elution-concentration methodology based on skimmed milk flocculation from three varieties of tomatoes (Solanum lycopersicum L. [globe], Solanum lycopersicum var. cerasiforme [cherry] and hybrid cocktail [grape tomato]) for further monitoring of field samples. Spiking experiments were performed to determine the success rate and efficiency recovery of human norovirus (NoV) genogroup II, norovirus murine-1 (MNV-1) used as sample process control virus and human adenovirus (HAdV). Mean values of 18.8%, 2.8% and 44.0% were observed for NoV GII, MNV-1 and HAdV, respectively with differences according to the types of tomatoes, with lower efficiency for cherry tomatoes. Analysis of 90 samples, obtained at commercial establishments in the metropolitan region of Rio de Janeiro State, revealed 4.5% positivity for HAdV. Bacterial analysis was also performed with no detection of Salmonella spp., L. monocytogenes and fecal coliforms. Data demonstrated that the skimmed milk flocculation method is suitable for recovering HAdV from tomatoes and highlights the need for considering investigation in order to improve food safety.

Evaluation of skimmed milk flocculation method for virus recovery from tomatoes

Abstract This study aimed to evaluate the elution-concentration methodology based on skimmed milk flocculation from three varieties of tomatoes (Solanum lycopersicum L. [globe], Solanum lycopersicum var. cerasiforme [cherry] and hybrid cocktail [grape tomato]) for further monitoring of field samples. Spiking experiments were performed to determine the success rate and efficiency recovery of human norovirus (NoV) genogroup II, norovirus murine-1 (MNV-1) used as sample process control virus and human adenovirus (HAdV). Mean values of 18.8%, 2.8% and 44.0% were observed for NoV GII, MNV-1 and HAdV, respectively with differences according to the types of tomatoes, with lower efficiency for cherry tomatoes. Analysis of 90 samples, obtained at commercial establishments in the metropolitan region of Rio de Janeiro State, revealed 4.5% positivity for HAdV. Bacterial analysis was also performed with no detection of Salmonella spp., L. monocytogenes and fecal coliforms. Data demonstrated that the skimmed milk flocculation method is suitable for recovering HAdV from tomatoes and highlights the need for considering investigation in order to improve food safety.

Group A rotavirus detection on environmental surfaces in a hospital intensive care unit.

BACKGROUND: Environmental surfaces can play a role in the spread of pathogens, such as enteric viruses, within a hospital. This study assessed the level of contamination of group A rotavirus (RV-A) on environmental surfaces samples from an adult intensive care unit in a hospital in Rio de Janeiro, Brazil. METHODS: A total of 504 environmental surface samples were obtained from multiple sites in the intensive care unit, including flushing buttons, telephones, and alcohol gel supports. Nested and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) were used to detect and quantify RV-A levels through partial amplification of VP6 and NSP3 genes, respectively, and the viability of the viruses detected was assessed by MA-104 cell integrated cell culture/RT-PCR. RESULTS: RV-A was detected by nested RT-PCR in 14% of the samples (73 of 504), with viral loads ranging from 3.4 genomic copies/mL to 2.9 × 10(3) genomic copies/mL. The nucleotide sequence of the amplicons obtained from nested RT-PCR confirmed that the positive samples were RV-A. Moreover, 3 of 10 strains investigated demonstrated viability by integrated cell culture/RT-PCR. CONCLUSION: The detection of RV-A on environmental surface samples indicates a need for improvements to hospital cleaning procedures to reduce viral contamination, and suggests, as reported previously, that RV-A can be used as a biomarker to assess contamination in hospitals.