L. plantarum cells, grown in MRS
broth for 48 hours, were harvested by
centrifugation at 5000 r/m for 15
minutes, washed twice with sterilel.0%
NaCl solution and finally resuspended
in 10 ml sterile diluent. LAB cell
suspension was prepared once in two
days and stored at 4°C until used. Cells
of V. harveyi MA 534, grown in SPYE
broth, were harvested as done with
LAB cells and used immediately for
experimental infection studies. Numbers
of viable cells of L. plantarum and
V. harveyi in the suspensions were
determined on MRS agar and SPYE
agar, respectively. Agar disc diffusion
method of Bauer et al. (1966) was
followed for testing the antibiogram of
V. harveyi. The minimal inhibitory
concentration (MIC) of antibiotics was
determined by agar dilution method
(Abraham et al., 1997). Pathogenicity of
V. harveyi was tested on P. indicus
larvae at mysis-3 stage by immersion
method (Karunasagar et al., 1994).