TABLE 2.

Disk susceptibility of host strain, clones, and S. marcescens parent straina

AntibioticZone diam (mm) for:
E. coli NM522-pTZ19SCH909pGM172pST2
Neomycin1981818
Kanamycin2461026
Tobramycin2271024
5′-Episisomicin22121222
Gentamicin2581224
Amikacin26222226
Isepamicin30262830
Netilmicin26181426
2′-N-Ethylnetilmicin30121230
Apramycin28282830
6′-N-Ethylnetilmicin24263028
Fortimycin A3063030
  • a Disk susceptibility data show a typical AAC(6′)-II profile for the clone of the entire fusion protein but not for that of the ant(3")-Ii moiety. The sequence of the ant(3")-Ii gene is 84% similar to those of the known ant(3")-Ia gene from Tn21 and ant(3")-Ib from pSa. aac(6′)-IId is a point mutation of aac(6′)-Ib resulting in the amino acid change L119→S, which changes the specificity from Akr Gms to Aks Gmr.