ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Abstract Escherichia coli F-18, a normal human fecal isolate, and Salmonella typhimurium SL5319, an avirulent strain, are known to colonize the streptomycin-treated CD-1 mouse large intestine by utilizing nutrients present in intestinal mucus for growth. Moreover, previous experiments suggested the possibility that E. coli F-18 and S. typhimurium SL5319 utilized different mucus nutrients. Therefore, mouse cecal mucus was fractionated into high and low molecular weight components, and each fraction was inoculated either simultaneously or separately with E. coli F-18 and S. typhimurium SL5319. A 50 kd fraction was found in which the growth of S. typhimurium SL5319 suppressed growth of E. coli F-18. Evidence is presented that in this fraction S. typhimurium SL5319 utilizes peptides, presumably generated by mucus proteases, as a source of amino acids for growth. Furthermore, it is shown that S. typhimurium SL5319 grows in this 50 kd fraction with a generation time of 27 min in the presence of at most 7 μg of carbohydrate per ml and 2.2 μg of peptide per ml, and that S. typhimurium SL5319 suppresses E. coli F-18 growth in this fraction by sequestering iron. The data are discussed with respect to the role of peptide utilization and iron sequestration in the ability of S. typhimurium SL5319 to colonize the mouse large intestine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1990.tb04068.x
Permalink