DEVELOPMENT OF A SPECIES-SPECIFIC PROBE FOR DETECTION OF SERRATIA ENTOMOPHILA IN SOIL

摘要

Strains of the bacteria Serratia entomophila and S. proteamaculans cause amber disease in the grass grub Costelytra zealandica (Coleoptera: Scarabaeidae), an important pasture pest in New Zealand. Strains of both Serratia species occur naturally in New Zealand pasture soils. Serratia entomophila has been developed as a commercial biological control agent, bioshield TM . The persistence of the applied strain in soil is currently measured by enumeration of bacterial colonies on Serratia- selective agarand subsequent biochemical tests are carried out to differentiate between the two Serratia species, on the basis of their ability to utilise itaconate as a sole carbon source. A species-specific DNA probe has been developed as an alternative to these laborious biochemical tests. Tests against a range of Serratia species in colony dot blots showed the probe could be used to differentiate between S. entomophila and S. protemaculans recovered from treated soil when assessing persistence of bioshield?inoculum and efficacy of the product in the field.