while all strains had mic values greater than 32 mg/l for colistin , false susceptibility to both polymyxins was encountered in the 24 h disk test in 9 % of serratia marcescens and 12-96 % of serratia liquefaciens strains , depending on the kind of polymyxin , temperature and duration of incubation .
C0009316
colistin
C0032539
polymyxin