Antibiotic Resistance of Pectobacterium Korean Strains Susceptible to the Bacteriophage phiPccP-1

Commercial products with antibiotics like streptomycin as active ingredients have been used to control soft rot disease caused by Pectobacterium species for a long time. In this study, antibiotic resistance of twentyseven Korean strains of Pectobacterium species including P. carotovorum, P. odoriferum, P. brasiliense, and P. parmenteri, which were previously shown to be susceptible to the bacteriophage phiPccP-1 was surveyed using a disk diffusion assay. While all strains were highly susceptible to ampicillin, kanamycin, chloramphenicol, tetracycline, and rifampicin, some strains showed weak susceptibility to 300 μg/ml of streptomycin. Furthermore, some of them are partially or completely resistant to commercial pesticides—Buramycin and streptomycin at the concentration of 250 μg/ml that is recommended by the manufacturer for streptomycin- based pesticides. These results indicate the presence of streptomycin-resistant Pectobacterium strains in South Korea, and the development of antibiotic alternatives to control soft rot is needed.