TABLE 5.

Molecular genetic characterization of laboratory-generated S. aureus mutants with decreased susceptibility to REP8839

Isolation methodIsolate(s)Parental strain (phenotypea)MIC (μg/ml)MetS mutation(s)
Spontaneous resistanceSSM5, others (25 isolates)ATCC 292134-8157N
SR5-1; SR5-2ATCC 43300 (MRSA)8157N
FSM 9, others (6 isolates)87-2797 (MRSA, HL-MupR)4-16I57N
SR23-1LZ10 (MRSA)8I57N
SR59-1, SR59-21079077 (MRSA)8I57N
SR74-2MB000193 (MRSA)8I57N
SR3, SR18, SR21ATCC 2921316-32G54S
FSM787-2797 (MRSA, HL-MupR)16G54S
SR74-1MB000193 (MRSA)16G54S
SR84-1, SR84-2MB000057 (MRSA)16G54S
SR23-2LZ10 (MRSA)32G54S
SR19, SR23ATCC 292130.5-1None
FSM887-2797 (MRSA, HL-MupR)1None
Serial passageSP-1B5, SP-2D4, others (8 isolates)ATCC 29213, ATCC 43300, others8-16I57N
SP-21C31-1334 (MRSA, LL-MupR)8I57T
SP-27H10-420 (MRSA, HL-MupR)4E52D
SP-27D14-354 (MRSA, LL-MupR)2A61V
SP-21AATCC 292134A77V
SP-25GLZ6 (MRSA, HL-MupR)8V108M
SP-2C4ATCC 43300 (MRSA)2L213W
SP-28B25-670 (MRSA, HL-MupR)4V215A
SP-4A287-2797 (MRSA, HL-MupR)8G223C
SP-11A331-1334 (MRSA, LL-MupR)81238F
SP-1A2ATCC 292134A247E
SP-9B5ATCC 292134I57N V296F
SP-2B5ATCC 43300 (MRSA)32I57N R100S
SP-4B587-2797 (MRSA, HL-MupR)32I57N V242F
SP-25C31-1334 (MRSA, LL-MupR)2T50A V242I
SP-26C1079101 (HL-MupR)32G54A A64P
SP-25FLZ1 (MRSA, HL-MupR)16A61T A64S
SP-22B25-670 (MRSA, HL-MupR)8A61T V108L
SP-21GLZ6 (MRSA, HL-MupR)2I94N V215A
SP-21H10-420 (MRSA, HL-MupR)8V215I V242F
SP-22C1079101 (HL-MupR)16L19F Q58L A64P
SP-25D14-354 (MRSA, LL-MupR)8A61T E98G M269I
SP-26B25-670 (MRSA, HL-MupR)4P230T A247E L257P
SP-21BATCC 43300 (MRSA)2None
SP-3A531-1334 (MRSA, LL-MupR)2None
SP-4D587-2797 (MRSA, HL-MupR)0.25None
Second-step mutationsSSM 1-01, SSM 1-02, SSM 1-03ATCC 2921332I57N A247E
SSM 6-01ATCC 2921332I57N G54S
SSM 6-02, 6-03ATCC 2921332I57N I238F
SSM 14-01, 14-02LZ6 (MRSA, HL-MupR)32G54S V108M
  • a HL-MupR, high-level mupirocin resistant; LL-MupR, low-level mupirocin resistant.