Posted: November 22nd, 2009 - 5:41pm
Source: Applied and Environmental Microbiology

Abstract
The attachment and internalization of murine norovirus-1 (MNV) in biosolids, swine manure and dairy manure to Romaine lettuce were evaluated. The MNV in animal manures had similar behavior as pure MNV, however, MNV in biosolids had significantly higher attachment as well as internalization than pure MNV or MNV in manures. The incubation time of MNV in biosolids or manure did not affect the attachment. Confocal microscopy was used to observe MNV on lettuce after directly adding SYBR-gold labeled MNV on to lettuce or after the lettuce was submersed in labeled virus. MNV was observed on the lettuce surface, inside the open cut and occasionally within the stomata. In general, the lettuce with a long cut on the edge and short cuts on the stems was more likely to contain internalized MNV than intact lettuce pieces as observed by confocal microscopy; however, while the difference was visible it was not statistically significant. The study showed that MNV in biosolids may increase the risk of fresh produce contamination, and the MNV in open cuts and stomata is likely to be protected from sanitization.