Klebsiella pneumoniae capsule expression is necessary for colonization of large intestines of streptomycin-treated mice

Citation
S. Favre-bonte et al., Klebsiella pneumoniae capsule expression is necessary for colonization of large intestines of streptomycin-treated mice, INFEC IMMUN, 67(11), 1999, pp. 6152-6156
Citations number
19
Categorie Soggetti
Immunology
Journal title
INFECTION AND IMMUNITY
ISSN journal
00199567 → ACNP
Volume
67
Issue
11
Year of publication
1999
Pages
6152 - 6156
Database
ISI
SICI code
0019-9567(199911)67:11<6152:KPCEIN>2.0.ZU;2-G
Abstract
The role of the Klebsiella pneumoniae capsular polysaccharide (K antigen) d uring colonization of the mouse large intestine was assessed with mild-type K. pneumoniae LM21 and its isogenic capsule-defective mutant. When bacteri al strains were fed alone to mice, the capsulated bacteria persisted in the intestinal tract at levels of 10(8) CFU/g of feces while the capsule-defec tive strain colonized at low levels, 10(4) CFU/g of feces. In mixed-infecti on experiments, the mutant was rapidly outcompeted by the wild type. In sit u hybridization on colonic sections revealed that bacterial cells of both s trains were evenly distributed in the mucus layer at day 1 after infection, while at day 20 the wild type remained dispersed and the capsule-defective strain was seen in clusters in the mucus layer. These results suggest that capsular polysaccharide plays an important role in the gut colonization ab ility of K. pneumoniae.