Structure-based characterization and optimization of novel hydrophobic binding interactions in a series of pyrrolidine influenza neuraminidase inhibitors.

The structure-activity relationship (SAR) of a novel hydrophobic binding interaction within a subsite of the influenza neuraminidase (NA) active site was characterized and optimized for a series of trisubstituted pyrrolidine inhibitors modified at the 4-position. Previously, potent inhibitors have targeted this subsite with hydrophilic substituents such as amines and guanidines. Inhibitor-bound crystal structures revealed that hydrophobic substituents with sp(2) hybridization could achieve optimal interactions by virtue of a low-energy binding conformation and favorable pi-stacking interactions with the residue Glu119.

Enteric Bacterial and Viral Pathogens and Indicator Bacteria in Hard Shell Clams.

Enteric bacteria and virus levels were determined in hard shell clams, Mercenaria mercenaria , harvested from areas open or closed for commercial shellfishing on the basis of total coliform levels in water. Four pairs of open and closed stations were sampled seasonally over a 1-year period. Enteric viruses were isolated from 3 of 13 100-g clam samples from open beds and 6 of 15 samples from closed beds.

Occurrence of Enteric Bacteria and Viruses in Oysters.

Enteric bacteria and virus levels were determined in oysters from paired stations that were opened or closed for commercial shellfishing on the basis of total coliform levels in the water. Six pairs of stations were sampled quarterly over a 1-year period. Enteric viruses were found in 3 of 24 50-g oyster samples from closed areas and in none of 23 samples from open areas.