Comparison of two commercial kits for biochemical characterization ofPaenibacillus larvae larvae in the diagnosis of AFB

摘要

The use of commercial kits for the biochemical characterization of bacteria is a general practice for quick and reliable identification of a wide range of bacterial species. In the case of Paenibacillus larvae subsp, larvae, Carpana et al. (1995) described the use of the API 50CHB kit (BioMerieux, Brussels, Belgium) for the diagnosis of American foulbrood (AFB). Here we describe the use of another kit, i.e. BBL CRYSTAL (Becton Dickinson, Aalst, Belgium) and compare the results with those obtained by using the APl 50CHB kit. We have chosen to test the BBL CRYSTAL kit for its suitability to identify P. I. larvae because in the Veterinary and Agrochemical Research centre (Brussels, Belgium) this kit is the standard test kit for biochemical characterization of bacteria. It was found to be more userfriendly then the APl kits and it provides results in 24 h, whereas the APl kit requires 48 h. The BBL CRYSTAL kit was tested on 11 P. I. larvae field strains (outbreaks from 1997 and 1998) in addition to three P. I. larvae reference strains from the LMG-collection (Laboratory of Microbiology Ghent, University of Ghent) (i.e. LMG 14425, LMG 14426 and LMG 15969). The APl 50CHB kit was tested on the same three P. I. larvae reference strains and six field strains from the outbreaks of 1997. Two P. alvei reference strains (i.e. LMG 13253 and LMG 13258) and two Bacillus licheniformis field strains were used in both kits as negative control. In addition to this, reference strains of B. cereus (LMG 6923), B. megaterium (LMG 7127), B. subtilis (LMG 7135), B. thuringiensis (LMG 7138), P. validus (LMG 9817), P. lautus (LMG 11157), P. polymyxa (LMG 13296), P. I. pulvifaciens (LMG 15974) and P. apiarius (LMG 17433) were tested with the BBL kit in order to evaluate the discriminatory power of the kit between species related to P. I. larvae. The BBL CRYSTAL and API 50CHB kits were used according to manufacturers instructions.