Screening Systems for Detecting Inhibitors of Cell Wall Transglycosylation in Enterococcus: Cell Wall Transglycosylation Inhibitors in Enterococcus

• Published in: Journal of antibiotics 1998/05/25, Vol.51(5), pp.471-479
• Main Authors: MANI, NAGRAJ, SANCHET, PRAVEEN, JIANG, ZHI-DONG, MCNANEY, COLLEEN, DECENZO, MAUREEN, KNIGHTI, BEN, STANKIS, MARY, KURANDA, MIKE, ROTHSTEIN, DAVID M.
• Format: Article
• Language: English
• Subjects: Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Base Sequence; Biological and medical sciences; Cell Wall - drug effects; Enterococcus faecalis - drug effects; Fermentation; Glycosylation; Hydroxybenzoates - chemistry; Hydroxybenzoates - pharmacology; Medical sciences; Microbial Sensitivity Tests; Molecular Structure; Oligodeoxyribonucleotides; Pharmacology. Drug treatments; Vancomycin - pharmacology
• ISSN: 0021-8820; 1881-1469
• DOI: 10.7164/antibiotics.51.471

We devised two screening systems to detect cell wall transglycosylation inhibitors. One screen utilizes a mutant of Enterococcus faecalis strain A256 that is dependent on vancomycin or moenomycin for growth. In the absence of transglycosylation inhibitors the strain fails to grow, while in the presence of inhibitors, cells are rescued. A second screening organism E. faecalis strain MDD212 utilizes a translational fusion of the lacZ gene to the vanH promoter in a derivative of E. faecalis that contains a vancomycin resistance determinant. Induction of β-galactosidase occurs when cells are exposed to inhibitors of transglycosylation. Our natural products drug source of fungal fermentations was tested with these screens. Several cultures that produced the same family of compounds, called the thielavins, were detected. Thielavin B inhibited the formation of peptidoglycan in an in vitro assay, suggesting that these screening systems can detect compounds that interfere with cell wall transglycosylation.