BRETT PJ, VASU SK, GRANT CC, LEVIN JC, MCKENZIE DT; Interscience Conference on Antimicrobial Agents and Chemotherapy (42nd : 2002 : San Diego, Calif.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2002 Sep 27-30; 42: abstract no. F-740.

Quorex Pharmaceuticals, Carlsbad, CA

BACKGROUND:5'-Methylthioadenosine Nucleosidase/S-Adenosylhomocysteine Nucleosidase (Pfs) catalyzes the hydrolysis of 5'-methylthioadenosine (MTA) to 5'-methylthioribose (MTR) and S-adenosylhomocysteine (SAH) to S-ribosylhomocysteine (SRH) in prokaryotes but not mammalian cells. Since MTA and SAH are potent inhibitors of important cellular processes in prokaryotes, Pfs represents an attractive target for the development of novel broad-spectrum antimicrobial compounds. In the present study we have examined the importance of Pfs activity in a variety of pathogenic and non-pathogenic bacterial species. METHODS: Allelic exchange and insertional inactivation mutagenesis strategies were used to construct pfs null mutations in E. coli, S. typhimurium, Haemophilus influenzae, Enterococcus faecalis, Streptococcus pneumoniae and Streptococcus pyogenes. Growth curves were conducted in both rich and chemically defined media. AI-2 production was quantitated using the Vibrio harveyi reporter assay. Carbohydrate utilization profiles were determined using API 50 CH strips incubated under anaerobic and aerobic conditions. An A/J mouse model of acute sepsis was used to assess the virulence phenotype of the S. typhimurium pfs mutant. RESULTS: Phenotypic analysis of the E. coli and S. typhimurium pfs mutants demonstrated attenuated growth profiles, the inability to synthesize AI-2 and altered carbohydrate utilization profiles in comparison to the parental strains. The S. typhimurium pfs null mutant also demonstrated proliferation deficiencies in Hela cells and a >30 fold decrease in virulence relative to the parental strain. We were unable to isolate H. influenzae, E. faecalis, S. pyogenes and S. pneumoniae pfs null mutants. Conclusion: Although Pfs activity is non-essential in E. coli and S. typhimurium, mounting evidence suggests that it may be essential in H. influenzae, E. faecalis, S. pyogenes, S. pneumoniae.

Publication Types:

• Meeting Abstracts

Keywords:

• 5'-methylthioadenosine phosphorylase
• Animals
• Catalysis
• Humans
• Mice
• N-Glycosyl Hydrolases
• Purine-Nucleoside Phosphorylase
• Vibrio
• adenosylhomocysteine nucleosidase

Other ID:

• GWAIDS0028276

UI: 102267900

From Meeting Abstracts