ABSTRACT
BACKGROUND: rotaviruses are the major cause of acute gastroenteritis in young children worldwide, and require careful surveillance, especially in the context of vaccination programs. Prospective surveillance is required to monitor and characterize rotavirus infections, including viral and clinical data, and to detect the emergence of potentially epidemic strains. METHODS: between 2006 and 2009, stool samples and clinical records were collected from 2044 children with acute diarrhea admitted to the pediatric emergency units of 13 French university hospitals. Rotaviruses were detected in stools, then genotyped by reverse transcription-polymerase chain reaction with regard to their outer capsid proteins VP4 and VP7. RESULTS: the genotyping of 1947 rotaviruses showed that G1 (61.7%) and G9 (27.4%) strains were predominant and stable, followed by G2 (6.5%), G3 (4.0%), and G4 (2.5%) strains. Most strains were associated with P[8] (92.9%). Overall, 31 uncommon strains and possible zoonotic reassortants were detected including G12 and G8 strains, some being closely related to bovine strains. No difference in clinical presentation and severity was found among genotypes. CONCLUSIONS: the relative stability of rotavirus genotypes currently cocirculating in France may ensure vaccine effectiveness in the short and medium term. However, the likely emergence of G12 and G8 strains should be monitored during ongoing and future vaccination programs, especially as all genotypes can cause severe infections. Special attention should be paid to the emergence of new rotavirus reassortants not included in current rotavirus vaccines.
Subject(s)
Gastroenteritis/pathology , Gastroenteritis/virology , Rotavirus Infections/pathology , Rotavirus Infections/virology , Rotavirus/classification , Animals , Antigens, Viral/genetics , Capsid Proteins/genetics , Cattle , Child, Preschool , Cluster Analysis , Emergency Service, Hospital , Feces/virology , Female , France , Genotype , Hospitalization , Hospitals, University , Humans , Infant , Male , Molecular Sequence Data , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Rotavirus/genetics , Rotavirus/isolation & purification , Sequence Analysis, DNAABSTRACT
Addition of methylated ß-lactoglobulin (Met-BLG) in the medium of MDCK cell lines infected with influenza virus subtype H1N1 reduced hemagglutination activity (HA) in a concentration dependent manner. Antiviral activity of Met-BLG depended on its concentration, viral load, and duration of infection. Using 17 µg/ml of Met-BLG inhibited 50% of HA of H1N1 grown in MDCK cells at 1 MOI after 24 h incubation at 37°C and in 5% CO2. Extension of incubation time enhanced antiviral action since the same concentration of Met-BLG inhibited about 61% of viral activity after 48 h. This viral inhibition was accompanied by a protection of MDCK cells as observed by using neutral red or by direct microscope examination. Reduction of viral RNA replication upon the addition of Met-BLG (50 µg/ml) was observed by real time-PCR showing a reduction of viral log value of about 0·9. When viral stock solution was mixed with 25 µg/ml Met-BLG in absence of cell lines, the morphology and viability of virus particles were significantly affected as observed by electron microscopy, and the number of intact virus particles was reduced by roughly 65%.
