Identification of a plasmid-borne chloramphenicol-florfenicol resistance gene in Staphylococcus sciuri

Abstract

The 16.5-kbp plasmid pSCFS1 from Staphylococcus sciuri mediated combined resistance to chloramphenicol and florfenicol. The gene responsible for this resistance property, cfr, was cloned and sequenced. The amino acid sequence of the Cfr protein revealed no homology to known acetyltransferases or efflux proteins involved in chloramphenicol and/or florfenicol resistance or to other proteins whose functions are known.

FIG. 1

Restriction map of plasmid pSCFS1 from S. sciuri and subcloning strategy for obtaining restriction fragments which mediate (or do not mediate) resistance to CM and FF. Restriction enzyme abbreviations: B, BclI; Ba, BamHI; Bs, BstEII; C, ClaI; E, EcoRI; EV, EcoRV; Hp, HpaI; Ms, MspI; P, PvuII; Ps, PstI; S, SacI; X, XbaI. A distance scale in kilobase pairs is given below each map. Arrows, locations of the cfr reading frames, ORF1 and ORF2, and their directions of transcription.

FIG. 2

Amino acid alignment of the Cfr protein from S. sciuri with similar proteins from M. tuberculosis H37RV, S. coelicolor A3(2), E. coli K12, H. influenzae Rd, P. aeruginosa PAO1, Synechocystis sp. strain PCC6803, T. maritima MSB8, B. subtilis 16, and T. pallidum produced with the DNAMAN sequence analysis software (Lynnon BioSoft, Vaudreuil, Quebec, Canada). Black boxes, identical amino acids; gray boxes, homologous amino acids which are present in at least 40% of the aligned sequences.