title: Detection of the staphylococcal multiresistance gene cfr in Proteus vulgaris of food animal origin.
abstract: OBJECTIVE
  To investigate the presence and the genetic environment of the multiresistance gene cfr in naturally occurring Gram-negative bacteria of pigs.
  
  
  METHODS
  A total of 391 bacterial isolates with florfenicol MICs of ≥16 mg/L, obtained from 557 nasal swabs of individual pigs, were screened by PCR for the known florfenicol resistance genes. The species assignment of the cfr-carrying isolate was based on the results of Gram's staining, colony morphology, 16S rDNA sequencing and biochemical profiling. The location of the cfr and floR genes was determined by Southern blotting and the regions flanking the cfr gene were sequenced by a modified random primer walking strategy.
  
  
  RESULTS
  A single Proteus vulgaris isolate, which carried the genes floR and cfr, was detected in this study. A cfr-carrying segment of 7 kb with homology to a staphylococcal plasmid was found to be inserted into the chromosomal fimD gene of P. vulgaris. This segment was flanked by two IS26 elements located in the same orientation, which are believed to have played a role in this integration process. Stability testing via inverse PCR approaches showed that this integrate is not entirely stable, but the cfr-carrying centre region plus one IS26 copy can be looped out via IS26-mediated recombination.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report of the cfr gene in a naturally occurring Gram-negative bacterium. Surveillance and monitoring of the cfr gene in Gram-negative bacteria are warranted with respect to food safety and consumer protection.
authors.affiliation: Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China. sjz@cau.edu.cn
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Cong-Ming
authors.initials: CM
authors.lastname: Wu
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Zhangqi
authors.initials: Z
authors.lastname: Shen
authors.forename: Wanjiang
authors.initials: W
authors.lastname: Zhang
authors.forename: Qijing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Shen
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification*; D001483:Base Sequence; D004251:DNA Transposable Elements; D004275:DNA, Ribosomal / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D036781:Fimbriae Proteins / Q000235:genetics; D005516:Food Microbiology; D059022:Food Safety; D000069349:Linezolid; D008826:Microbial Sensitivity Tests; D023303:Oxazolidinones / Q000494:pharmacology; D011514:Proteus vulgaris / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013210:Staphylococcus / Q000187:drug effects / Q000235:genetics; D034421:Sus scrofa / Q000382:microbiology; D013839:Thiamphenicol / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C539943:CFR protein, Staphylococcus aureus; D004251:DNA Transposable Elements; D004275:DNA, Ribosomal; D023303:Oxazolidinones; D012336:RNA, Ribosomal, 16S; C063629:fimD protein, bacteria; D036781:Fimbriae Proteins; C035534:florfenicol; D013839:Thiamphenicol; D000069349:Linezolid