TABLE 1.

Characteristics of VRE isolated from humans and imported chickens in Japan

Class and speciesStrainaOriginSource (specimen and/or reference)Transfer frequency of vancomycinb resistance from wild-type strain to E. faecalis FA2-2 (no. of transconjugants/donor cell)MIC (μg/ml)cDeduced amino acid sequence or amino acid substitution(s) of VanS of VanA-type determinant
VancomycinTeicoplanin
High teicoplanin resistance
    E. faeciumBM4147FranceHuman (1)<10−81,024256Prototype
    E. faeciumFN1JapanHuman (urine; 6)<10−8256128Prototype
    E. faeciumEF1JapanHuman (feces)<10−8512128Prototype
    E. faeciumEF2JapanHuman (feces)<10−851264Prototype
    E. faeciumEF3JapanHuman (drainage)<10−851264Prototype
    E. faeciumEF4JapanHuman (feces)<10−851264Prototype
    E. faeciumFV1FranceChicken<10−851264Prototype
    E. faeciumFV2FranceChicken10−551264Prototype
    E. faecalisFV3FranceChicken<10−8512128D58L
Low teicoplanin resistance
    E. faeciumKV12JapanHuman (feces)10−41,0244L50V, E54Q, Q69H
    E. faeciumKV21JapanHuman (feces)10−45122L50V, E54Q, Q69H
    E. faeciumCV1JapanHuman (feces)<10−85120.5L50V, E54Q, Q69H
    E. faecalisTV1ThailandChicken10−45124L50V, E54Q, Q69H
    E. faecalisTV2ThailandChicken<10−85124L50V, E54Q, Q69H
    E. faecalisTV3ThailandChicken<10−851216L50V, E54Q, Q69H
    E. faecalisTV4ThailandChicken<10−81,02416L50V, E54Q, Q69H
    E. faecalisTV5ThailandChicken10−51,0242L50V, E54Q, Q69H
    E. faecalisTV6ThailandChicken<10−82564L50V, E54Q, Q69H
    E. duransTV7ThailandChicken<10−85122L50V, E54Q, Q69H
    E. duransTV8ThailandChicken<10−85122L50V, E54Q, Q69H
    E. duransTV9ThailandChicken10−55124L50V, E54Q, Q69H
    E. duransTV10ThailandChicken10−451216L50V, E54Q, Q69H
    E. duransTV11ThailandChicken10−51,02416L50V, E54Q, Q69H
    E. faecalisGV2JapanBroiler farm droppings (18)10−45122L50V, E54Q, Q69H
  • a E. faecium BM4147 is a representative VanA-type strain, and the glycopeptide resistance determinant is encoded on transposon Tn1546. Strains TV1, TV2, TV3, TV7, and FV3 and strains TV4, TV5, TV6, TV8, TV9, TV10, TV11, FV1, and FV2 were isolated in investigations done in March 1998 and March 1999, respectively. Strains KV12 and KV21 and strain CV1 were isolated in November 1997 and July 1998, respectively.

  • b Filter matings were performed with a donor/recipient ratio of 1:4. The recipient strain was E. faecalis FA2-2 (Rifr Fusr). The donor and recipient cells were trapped on a membrane filter (Millipore Corporation, Bedford, Mass.), incubated on a Todd-Hewitt broth (THB) agar plate at 37°C for 18 h, and suspended in 1 ml of THB. Appropriate dilutions of the mating mixture were plated onto THB agar plates containing vancomycin at 12.5 μg/ml plus rifampin at 25 μg/ml and fusidic acid at 25 μg/ml for counterselection of the donor strain, and the plates were incubated for 48 h at 37°C.

  • c Glycopeptide resistance levels were determined by the agar dilution method with Mueller-Hinton agar in accordance with NCCLS criteria.