Evaluation of the substitution of poliomyelitis virus for testing virucidal activities of instrument and surface disinfection.

The Global Polio Eradication initiative has the goal to eradicate poliomyelitis worldwide. This means that poliomyelitisvirus type 1 strain LSc 2ab (PV-1) can no longer be used for the evaluation of virucidal activity of chemical disinfectants. This study evaluated murine parvovirus ATCC VR 1346 (minute virus of mice) as suitable surrogate for PV-1 when testing virucidal activity of biocides in instrument and surface disinfectants. Suspension testing in different laboratories with two commercially available active biocidal substances based on glutaraldehyde (0.01-0.25%) and peracetic acid (0.005-0.1%) with an exposure time of 30 min was performed. Both pathogens showed comparable susceptibility and dose-dependent reduction of virus titres following German and European Guidelines.

Iron limitation of microbial phosphorus acquisition in the tropical North Atlantic.

In certain regions of the predominantly nitrogen limited ocean, microbes can become co-limited by phosphorus. Within such regions, a proportion of the dissolved organic phosphorus pool can be accessed by microbes employing a variety of alkaline phosphatase (APase) enzymes. In contrast to the PhoA family of APases that utilize zinc as a cofactor, the recent discovery of iron as a cofactor in the more widespread PhoX and PhoD implies the potential for a biochemically dependant interplay between oceanic zinc, iron and phosphorus cycles. Here we demonstrate enhanced natural community APase activity following iron amendment within the low zinc and moderately low iron Western North Atlantic. In contrast we find no evidence for trace metal limitation of APase activity beneath the Saharan dust plume in the Eastern Atlantic. Such intermittent iron limitation of microbial phosphorus acquisition provides an additional facet in the argument for iron controlling the coupling between oceanic nitrogen and phosphorus cycles.