Direct and indirect conductimetry for identification and detection of plant pathogenic bacteria

An automated conductimetric system was used to study the responses of some plant pathogenic bacteria in direct and indirect conductimetry. Strains of pathovars of Pseudomonas syringae and Xanthomonas campestris, one strains of Clavibacter michiganensis ssp. michiganensis Erwinia carovora ssp. atroseptica and Erwinia chrysanthemi were tested in Special Peptone Yeast Extract (SPYE), Malthus Columbia Broth (MCB) and Malthus Enterobacteriaceae Medium (MEM). In direct conductimetry the erwinias gave significantly lower detection times (the detection time was defined in direct conductimetry as the time to reach a conductance change of 100 μS) and much higher rates of conductance changes in SPYE and MCB than the pseudomonads and xanthomonads tested at 27 o C