Erythromycin resistance gene from the Bacteroides conjugal transposon Tc-r Em(r) 7853 is nearly identical to ermG from Bacillus sphaericus

Tc-r Em(r) 7853, from Bacteroides thetaiotaomicron 7853, is a large chromosomal conjugative transposon which encodes resistance to both tetracycline (Tc-r) and erythromycin (Em(r)). The erythromycin resistance gene of Tc-r Em(r) 7853 did not cross-hybridize with ermF, the Em(r) gene found on previously studied Bacteroides regular and conjugative transposons. We have cloned and sequenced the erythromycin resistance gene from Tc-r Em(r) 7853. The DNA sequence of this gene was 99.6% identical to that of ermG from Bacillus sphaericus.