Molecular characterization of a plasmid-borne (pGT633) erythromycin resistance determinant (ermGT) from Lactobacillus reuteri 100-63.
Lactobacillus reuteri 100-63 contains a 9.8 kb plasmid (pGT633) encoding resistance to the macrolide-lincosamide-streptogramin (MLS) type B antibiotics. The restriction endonucleases AccI, BamHI, BclI, EcoRI, EcoRV, HhaI, HindII, HpaI, KpnI, SalI, and SspI were employed to establish a physical map of pGT633. Next, genetic transfer experiments were conducted to establish the host range of pGT633. The results revealed that pGT633 replicated autonomously and encoded constitutive resistance to erythromycin in a variety of bacterial hosts, including Bacillus subtilis BD170, Streptococcus sanguis DL1, Staphylococcus aureus RN4220, and Enterococcus faecalis 19433, as well as several Lactobacillus spp. A 2.2 kb BamHI fragment of pGT633 containing the genetic determinant (ermGT) encoding resistance to erythromycin was cloned into Escherichia coli. Determination of the nucleotide sequence of ermGT revealed a methylase gene 731 bp in length that was highly related (ca. 81% nucleotide and ca. 78% amino acid identity) to the ermC gene from S. aureus plasmid pE194. The leader sequences of ermGT and ermC were identical except for a single base change at nt 51.
Tannock
G W
GW
Department of Microbiology, University of Otago, Dunedin, New Zealand.
Luchansky
J B
JB
Miller
L
L
Connell
H
H
Thode-Andersen
S
S
Mercer
A A
AA
Klaenhammer
T R
TR
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D004352:Drug Resistance, Microbial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics; D004917:Erythromycin / Q000633:toxicity*; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000187:drug effects / Q000235:genetics*; D008780:Methyltransferases / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010957:Plasmids; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000737:chemistry; D015183:Restriction Mapping; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics; D013298:Streptococcus sanguis / Q000187:drug effects / Q000235:genetics; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D004917:Erythromycin; D008780:Methyltransferases; C087013:ermGT protein, Lactobacillus reuteri