Assays to detect and characterize synthetic agents that inhibit the ErmC methyltransferase.
High throughput chemical file screening with an enzymatic assay to detect inhibitors of the ErmC methyltransferase enzyme from macrolide-lincosamide-streptogramin B (MLSB) resistant pathogenic bacteria identified low molecular weight compounds that had IC50S (50% inhibitory concentration) in the nMolar to microMolar range. These same inhibitors were assessed in vitro for their capacity to inhibit the liver enzyme, cathechol-O-methyltransferase and the prokaryotic enzyme, EcoRI methylase. Selective inhibitors of the ErmC methyltransferase were tested in tertiary assays to determine their minimal inhibitory concentrations (MICs), as single agents and in combination with the macrolide, azithromycin, against strains of pathogenic bacteria expressing MLSB-resistance. Compounds that were active in vitro, alone or in combination with azithromycin, against strains of macrolide-resistant pathogens were tested in a mouse model of infection using an MLSB-resistant strain of Staphylococcus aureus or a macrolide-susceptible strain of Streptococcus pyogenes.
Clancy
J
J
Central Research Division, Pfizer, Inc., Groton, Connecticut 06340, USA.
Schmieder
B J
BJ
Petitpas
J W
JW
Manousos
M
M
Williams
J A
JA
Faiella
J A
JA
Girard
A E
AE
McGuirk
P R
PR
D000818:Animals; D000900:Anti-Bacterial Agents; D017963:Azithromycin / Q000008:administration & dosage / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology / Q000627:therapeutic use; D055231:Lincosamides; D018942:Macrolides; D008780:Methyltransferases / Q000037:antagonists & inhibitors*; D051379:Mice; D013203:Staphylococcal Infections / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects; D013290:Streptococcal Infections / Q000188:drug therapy; D013297:Streptococcus pyogenes / Q000187:drug effects; D014769:Virginiamycin
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D055231:Lincosamides; D018942:Macrolides; D014769:Virginiamycin; D017963:Azithromycin; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase