Porcine rotavirus closely related to novel group of human rotaviruses.

We determined nucleotide sequences and inferred amino acid sequences of viral protein (VP) 4, VP6, VP7, and nonstructural protein 4 genes of a porcine rotavirus strain (SKA-1) from Japan. The strain was closely related to a novel group of human rotavirus strains (B219 and J19).

Evaluation of the antiviral activity of chlorine dioxide and sodium hypochlorite against feline calicivirus, human influenza virus, measles virus, canine distemper virus, human herpesvirus, human adenovirus, canine adenovirus and canine parvovirus.

We evaluated the antiviral activity of a chlorine dioxide gas solution (CD) and sodium hypochlorite (SH) against feline calicivirus, human influenza virus, measles virus, canine distemper virus, human herpesvirus, human adenovirus, canine adenovirus and canine parvovirus. CD at concentrations ranging from 1 to 100 ppm produced potent antiviral activity, inactivating >or= 99.9% of the viruses with a 15 sec treatment for sensitization. The antiviral activity of CD was approximately 10 times higher than that of SH.

Inactivation of feline calicivirus, a norovirus surrogate, by chlorine dioxide gas.

The efficacy of gaseous chlorine dioxide (ClO2) against feline calicivirus (FCV), a norovirus surrogate, in the dry and the wet states on a hard surface was evaluated. We demonstrated that low-concentration ClO2 gas (mean 0.08 ppm, 0.22 microg/I) could inactivate FCV in the wet state with 0.5% fetal bovine serum (FBS) within 6 h in 45 to 55% relative humidity (RH) (> 3 log10 reductions) and FCV in the dry state with 2% FBS (percentage of FBS in the viral suspension) within 10 h in 75 to 85% RH (> 3 log10 reductions) at 20 degrees C, respectively. Furthermore, a < 0.3 ppm concentration of ClO2 gas (mean 0.26 ppm, 0.73 microg/l) could inactivate (below the detection limit) FCV in the dry state with 5% FBS within 24 h in 75 to 85% RH at 20 degrees C. In contrast, in 45 to 55% RH at 20 degrees C, ClO2 gas had little effect even when the FCV in the dry state was exposed to high-concentration ClO2 (mean 8 ppm, 22.4 microg/l) for 24 h. These results suggest that humidity plays an important role in the inactivation by ClO2 gas of FCV in the dry state. According to the International Chemical Safety Card, threshold limit values for ClO2 gas are 0.1 ppm as an 8-h time-weighted average and 0.3 ppm as a 15 min short-term exposure limit. From these data, we propose that the treatment of wet areas of human activity such as kitchens, toilets, etc., with low-concentration ClO2 gas would be useful for reducing the risk of infection by noroviruses (NV) without adverse effects. In addition, we believe that the application of a combination of a < 0.3 ppm concentration of ClO2 gas and a humidifier in places without human activity may make it possible to inactivate NV in the dry state on any surface within a contaminated room without serious adverse effects.

Overexpression of monodehydroascorbate reductase in transgenic tobacco confers enhanced tolerance to ozone, salt and polyethylene glycol stresses.

Ascorbate (AsA) is a major antioxidant and free-radical scavenger in plants. Monodehydroascorbate reductase (MDAR; EC 1.6.5.4) is crucial for AsA regeneration and essential for maintaining a reduced pool of AsA. To examine whether an overexpressed level of MDAR could minimize the deleterious effects of environmental stresses, we developed transgenic tobacco plants overexpressing Arabidopsis thaliana MDAR gene (AtMDAR1) in the cytosol. Incorporation of the transgene in the genome of tobacco plants was confirmed by PCR and Southern-blot analysis and its expression was confirmed by Northern- and Western-blot analyses. These transgenic plants exhibited up to 2.1-fold higher MDAR activity and 2.2-fold higher level of reduced AsA compared to non-transformed control plants. The transgenic plants showed enhanced stress tolerance in term of significantly higher net photosynthesis rates under ozone, salt and polyethylene glycol (PEG) stresses and greater PSII effective quantum yield under ozone and salt stresses. Furthermore, these transgenic plants exhibited significantly lower hydrogen peroxide level when tested under salt stress. These results demonstrate that an overexpressed level of MDAR properly confers enhanced tolerance against ozone, salt and PEG stress.

Genetic analysis of group B human rotaviruses detected in Bangladesh in 2000 and 2001.

Group B rotaviruses detected in Bangladesh in 2000 and 2001 were analyzed genetically to clarify relatedness to human group B rotaviruses reported previously in China and India, and to animal group B rotaviruses. VP7 gene sequences of the Bangladeshi group B rotaviruses (Bang373, Bang544, Bang334, and Bang402) were almost identical to each other and also showed high sequence identity to the Indian strain CAL-1 (98%) and Chinese strain adult diarrhea rotavirus (ADRV) (92%), while identities to bovine and murine viruses were considerably low (60-63%). Other genes of Bang373 and Bang544 encoding VP2, VP4, VP6, and NSP1 through NSP5 also showed much higher sequence identities to those of CAL-1 (97.7-99.4%) than to those of ADRV (89.9-93.9%). Characterization of nucleotide substitutions among Bang373, CAL-1, and ADRV suggested that all the gene segments might have evolved neutrally at similar mutation rates, while some of the gene segments (e.g., VP2 gene) were suggested to be more conserved than others. In conclusion, group B rotaviruses detected in Bangladesh represented by Bang373 and the Indian virus CAL-1 were considered as virtually identical viruses which are distinct genetically from ADRV, and it was suggested that Bang373 (CAL-1)-like group B rotavirus (Bengali strains) might be distributed primarily in an area around the Bay of Bengal.

Human group B rotavirus infections cause severe diarrhea in children and adults in Bangladesh.

Human group B rotavirus was detected in 12 of 220 adult patients and 2 of 67 child patients with severe diarrhea in Bangladesh. Group B rotavirus may be virulent in both adults and children, and the virus may be an especially serious diarrheal agent in Bangladesh.