Detection of R Plasmid Encoded with Resistance to Florfenicol in Pasteurella piscicida.

Detection of Florfenicol Resistance Genes in Escherichia coli Isolated from Sick Chickens

“…The mechanism of resistance to florfenicol is unknown but is associated with the flo determinant, a highly conserved gene sequence detected in Salmonella enterica serovar Typhimurium DT104 (4,6) and in the fish pathogen Pasteurella piscicida (Photobacterium damsela) (15). The flo gene confers resistance to both chloramphenicol and florfenicol (4,14).…”

Sequence Analysis of the Florfenicol Resistance Gene Encoded in the Transferable R‐Plasmid of a Fish Pathogen, Pasteurella piscicida

“…However, we reported that FF-resistant strains of P piscicida appeared suddenly in 1992 (10). Transferable R-plasmids encoded with resistance to FF and also chloramphenicol (CP), kanamycin (KM), sulfonamide and tetracycline were detected in these drug-resistant strains of P piscicida (10). Moreover, a recombinant plasmid (pPF1) carrying the FF resistance determinant was obtained from a BamHI digest of the R-plasmid (10).…”

“…The sequence containing Si and S2 was thought to repeat in the same direction in the flanking regions of pp-flo. The R-plasmid carrying FF resistance was suspected to consist of an FF resistance deter- minant inserted into the transferable R-plasmid carrying the CP, KM, sulfonamide, and tetracycline resistance determinants (10). We suspect that pp-fib was inserted downstream from pp-sul, and that the sequence containing S1 and S2 may be an insertion sequence that has some function in the insertion of pp-fib.…”

Aquaculture and Florfenicol Resistance inSalmonella entericaTyphimurium DT104

“…Publication and accession dates do not, however, constitute evidence of the date of the fi rst isolation of a bacterium containing this gene. Analysis of the available chronological and molecular data presented here indicates that a variant of the fl oR gene in DT104 (9) was present in a terrestrial bacterium isolated in 1969 (10), 23 years before the fi rst isolation, in 1992, of a bacterium associated with aquaculture that contained this gene (5). It further demonstrates that this gene was present in strains of DT104 isolated in 1985.…”

“…comm. ), and this date for the introduction of fl orfenicol is also provided by Kim et al (5). It should, however, be noted that the fl o gene encodes resistance to both fl orfenicol and chloramphenicol and, therefore, fl o-containing bacteria could be selected for by the use of either agent.…”