Fusidic acid resistance, mediated by fusB, in bovine coagulase-negative staphylococci.
OBJECTIVE
The aim of this study was to determine the occurrence of fusidic acid resistance, mediated by the fusB gene, among coagulase-negative staphylococci (CoNS) isolated from bovine mastitis.


METHODS
A total of 113 CoNS isolates were screened for susceptibility to fusidic acid by using a disc diffusion method. The fusB gene was detected by using PCR and subsequent DNA sequencing. The localization of fusB was determined by hybridization.


RESULTS
The fusB gene was detected in 3 of 11 fusidic acid-resistant bovine CoNS isolates. The organization of the fusB downstream region on a 40 kb plasmid in a Staphylococcus haemolyticus isolate (288/96) was highly similar to the previously reported organization of fusB on plasmid pUB101 from a Staphylococcus aureus isolate of human origin. The fusB gene was chromosomally located in the remaining two isolates.


CONCLUSIONS
Fusidic acid resistance mediated by fusB is not the dominant resistance mechanism in fusidic acid-resistant CoNS studied in this work. The similarity between the organization of the fusB downstream region in S. haemolyticus (isolate 288/96) and on plasmid pUB101 from an S. aureus isolate of human origin indicates a common ancestral origin of these genes.
Yazdankhah
Siamak P
SP
Department of Food Safety and Infection Biology, The Norwegian School of Veterinary Science, Oslo, Norway. siamak.yazdankhah@fhi.no
Asli
Anette W
AW
Sørum
Henning
H
Oppegaard
Hanne
H
Sunde
Marianne
M
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002417:Cattle; D002876:Chromosomes, Bacterial / Q000235:genetics; D003030:Coagulase / Q000032:analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D019143:Evolution, Molecular; D005672:Fusidic Acid / Q000494:pharmacology*; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D008414:Mastitis, Bovine / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003030:Coagulase; D004269:DNA, Bacterial; C492443:FusB protein, Staphylococcus aureus; D005672:Fusidic Acid