TABLE 3.

Plating efficiencies in the presence of two antibiotics of a B. burgdorferi clone carrying both pBSV2 (kanamycin resistance) and pKFSS1 (streptomycin resistance) after 40 generations with or without selection

Treatmenta% of colonies compared to no antibioticb (±SEM)
KanamycinStreptomycinKanamycin and streptomycin
With selection95 (±1)70 (±5)79 (±8)
Without selection93 (±12)36 (±9)27 (±11)
  • a Selection with kanamycin and streptomycin.

  • b Plates without antibiotics yielded a mean of 448 colonies (= 100%) from the cultures grown for 40 generations with selection (both kanamycin and streptomycin) and 379 colonies (= 100%) from the cultures grown for 40 generations without selection.