TABLE 1

Phenotypes of proven and putative efflux pump mutants of E. coli a

Family and efflux geneDeletion phenotypeb (agent[s], fold decrease in MIC)Overexpression phenotypec (agent[s], fold increase in MIC)Agent(s) that inhibited growthdOther substrate(s) or information (reference)
RND
    acrB ACR, 128; AMP, 4; BAC, 32; CHL, 8; CIP, 4; CLO, >2; DAU, >128; DEO, >2; EB, 256; ERY, 32; FUA, 128; MTX, >8; NAL, 2; NOV, 64; PUR, 64; R6G, 512; SDS, >128; TET, 8; TPP, 256ACR, >16; BAC, 32; CHL, 8; CV, 8; DEO, >32; DOR, >64; ERY, 32; NAL, 4; NOR, 8; NOV, 64; R6G, 64; SDS, >8; TMP, >32;TPP, 16ACR, AMP, AZM, AZT, BAC, BLE, BS, CER, CHIR, CHL, CHO, CIP, CLR, CPZ, DEO, DOX, EB, ERY, FUA, MEC, MIN, NAL, NIT, NOR, NOV, OXA, PUR, SDS, SPT, SPR, STG, TCH, TCS, TET, TMP, TRX, VER
    acrD No changeDEO, >32; KAN, 2; NOV, 4; SDS, >8PAR
    acrF No changeACR, 8; DEO, 4; DOX, 2; SDS, 4PHL, VER
    yhiV (mdtF)No changeCV, 2; DEO, 4; DOR, 8; EB, 4; ERY, 8; R6G, 16; SDS, 4; TPP, 4FUA
    mdtB No changeDEO, >32; FOF, 2; NAL, 2; NOR, 2; NOV, 16; SDS, 4CIP, SDS
    mdtC No changeDEO, >32; FOF, 2; NAL, 2; NOR, 2; NOV, 16; SDS, 4BAT, CSD, NAL, PHL
MFS
    bcr ACR, 2; FOF, 4; KAN, 2; TET 4CHO, ERY, SMZ
    cmr (cmlA, mdfA)BC, 4; EB, 4ACR, 8; CHL, 16; DOX, 4; EB, 4; NOR, 8; TET, 2; TMP, 4; TPP, 4ACR, BAC, CHL, EBPentoses (1010)
    emrB No changeDEO, 32; PAR, 2; R6G, 2; SDS, 2EB, SXTCCCP, NAL, TSA (139); CER, TLM (15)
    emrD No changeBAC, 2; SDS, 2AZM, GEN, NIT, OXA, SMT, SPRUncouplers (15); pentoses (1010)
    emrY No change CEC, SMZ, TETH2O2, MIT, NAL, UV irradiation (1011)
    yajR EB, NIT, OXA, SPR, TMP
    yceB AMX, BAC, MEC, NAL, PAR
    yceE (mdtG) FOF, 4BAC, CAZ, MEC, MTX, PUR, SDS, TLM
    yceL (mdtH) ATM, EB
    ydeB (marC) ACT
    ydhC FUA, SPTPentoses (1010)
    yebQ AMK, CHL, CHO, CSD, DEO, ERY, FOX, NOV, PER, PMB, TET, VER
    yegB (mdtD) None with agents testedIron citrate (in Salmonella) (1012)
    yidY (mdtL) AMX
    yieO (hsrA) ACR, BAC, CAR, CHIR, CSD, DOX, EB, FOX, GFF, MIT, SDS, STR
    yjiO (mdtM) AZT, BLE, CAL, CHIR, CHL, CIP, CPZ, INH, OXA, SMZ, SPR, TETBinds CHL (1013)
    ynfM AMP, DEOPentoses (1010)
MATE (MOP)
    mdtK (ydhE, norM) BAC, 2; CHL, 2; DEO, 32; DOR, 8; EB, 2; FOF, 2; NOR, 8; PAR, 4; TMP, 4; TPP, 32CPZ, FUA, NOR, PUR, STR
    yeeO ACR, BAC, BIC, CAR, DOR, PUR, VAN, VER
SMR (DMT)
    emrE EB, 4; PAR, 8ACR, 16; BAC, 2; EB, 8; PAR, 2ACR, EB, FOF, PAREB (1014); PAR (1015); ERY (155); cationic osmoprotectants (159)
    ydgE (mdtI) DEO, 4; SDS, 2ACR, BAC, CHL, DEO, EB, FUA, MTX, PMB, PUR, TRXSpermidine (1016)
    ydgF (mdtJ) DEO, 4; SDS, 2CHO, CSD, ERY, NAL, VERSpermidine (1016)
ABC
    macB No changeERY, 8BAT, BIC, BS, CEC, EB, FOX, NIT, SDS, TCH
LysE
    argO AMP, BS, GFF, INH, NAL, PHL, TMPArginine (1017)
Unknown
    ycdZ NOR, SDS (not TET)TET, 1.7- to 2.5-fold decrease in MIC compared to the wild type (28)
  • a Abbreviations: ACR, acriflavine; ACT, actinomycin D; AMK, amikacin; AMP, ampicillin; AMX, amoxicillin; ATM, aztreonam; AZM, azithromycin; AZT, azidothymidine; BAC, benzalkonium chloride; BAT, bacitracin; BIC, bicyclomycin; BLE, bleomycin; BS, bile salts; CAL, calcofluor; CAR, carbenicillin; CAZ, ceftazidime; CCCP, carbonyl cyanide m-chlorophenylhydrazone; CEC, cefaclor; CER, cerulenin; CHIR, CHIR-900 (an LpxC inhibitor); CHL, chloramphenicol; CHO, cholate; CIP, ciprofloxacin; CLO, cloxacillin; CLR, clarithromycin; CPZ, chlorpromazine; CSD, cefsulodin; CV, crystal violet; DAU, daunomycin; DEO, deoxycholate; DOR, doxorubicin; DOX, doxycycline; EB, ethidium bromide; ERY, erythromycin; FOF, fosfomycin; FOX, cefoxitin; FUA, fusidic acid; GEN, gentamicin; GFF, glufosfomycin (fosfomycin plus glucose-6-P); INH, isoniazid; KAN, kanamycin; MEC, amdinocillin; MIN, minocycline; MIT, mitomycin; MTX, methotrexate; NAL, nalidixic acid; NIT, nitrofurantoin; NOR, norfloxacin; NOV, novobiocin; OXA, oxacillin; PAR, paraquat (methyl viologen); PER, peroxide; PHL, phleomycin; PMB, polymyxin B; PUR, puromycin; R6G, rhodamine 6G; SDS, sodium dodecyl sulfate; SMT, sulfamonomethoxine; SMZ, sulfamethizole; SPR, spiramycin; SPT, spectinomycin; STG, streptonigrin; STR, streptomycin; SXT, trimethoprim-sulfamethoxazole; TCH, taurocholate; TCS, triclosan; TDC, taurodeoxycholate; TET, tetracycline; TLM, thiolactomycin; TMP, trimethoprim; TPP, tetraphenyl phosphonium; TRX, Triton X-100; TSA, tetrachlorosalicylanilide; VAN, vancomycin; VER, verapamil.

  • b See reference 27. Numbers after the abbreviation for the agent name indicate the fold decrease in MIC in comparison with the wild-type strain.

  • c See reference 31. Numbers after the abbreviation for the agent name indicates the fold increase in MIC in comparison with the ΔacrAB parent strain.

  • d Only the antimicrobial agents, dyes, and detergents that significantly inhibited the growth of mutants more than that of the wild type, usually leading to growth scores of <−2 (30), are listed. Furthermore, we confirmed that the inhibition was reproducible by examining the data obtained with different concentrations of the same agent.