On the scope and management of pesticide pollution of Swedish groundwater resources: The Scanian example.

Twenty-three south-Swedish public supply wells were studied to assess pesticide pollution of regional groundwater resources. Relations between pesticide occurrence, hydrogeology, and land use were analyzed using Kohonen's Self-Organizing Maps approach. Pesticides are demonstrated to be substantially present in regional groundwater, with detections in 18 wells. Concentrations above the drinking water threshold are confirmed for nine wells. Observations indicate considerable urban influence, and lagged effects of past, less restricted use. Modern, oxic waters from shallow, unconfined, unconsolidated or fracture-type bedrock aquifers appear particularly vulnerable. Least affected waters appear primarily associated with deeper wells, anoxic conditions, and more confined sediment aquifers lacking urban influence. Comprehensive, standardized monitoring of pesticides in groundwater need to be implemented nationwide to enable sound assessments of pollution status and trends, and to develop sound groundwater management plans in accordance with the Water Framework Directive. Further, existing water protection areas and associated regulations need to be reassessed.

Targeting of streptococci by zoocin A.

Zoocin A is a domain-structured peptidoglycan hydrolase produced by Streptococcus equi ssp. zooepidemicus 4881. [(14)C]-zoocin A was used to measure the amount of zoocin A bound to the surface of cells and to purified peptidoglycan. The sensitivity of various streptococci to zoocin A correlated with the amount of zoocin A bound (R(2)=0.8609). Peptidoglycan purified from Streptococcus oralis and Streptococcus rattus were able to bind zoocin A but remained resistant to hydrolysis. All Streptococcus pyogenes strains were extremely sensitive to zoocin A with minimum inhibition concentrations of 31.5 ng mL(-1) or less, suggesting that zoocin A may have potential for use as an enzybiotic.