Utilization of the mouse large intestine to select an Escherichia coli F-18 DNA sequence that enhances colonizing ability and stimulates synthesis of type 1 fimbriae.
Escherichia coli F-18, a normal human fecal isolate, is an excellent colonizer of the streptomycin-treated mouse large intestine. E. coli F-18 Col-, a derivative of E. coli F-18 which no longer makes the E. coli F-18 colicin, colonizes the large intestine as well as E. coli F-18 when fed to mice alone but is eliminated when fed together with E. coli F-18. Random sequences of E. coli F-18 DNA were cloned into pRLB2, a par-B-stabilized derivative of pHC79. The entire gene library was transformed into E. coli F-18 Col- and fed to streptomycin-treated mice. The mouse large intestine selected a predominant clone which contained a recombinant plasmid (pRLB7) that enhanced E. coli F-18 Col- colonizing ability 100-fold but did not stimulate colicin synthesis. Moreover, pRLB7 simultaneously improved the survival of E. coli F-18 Col- in stationary phase in vitro, utilizing nutrients derived from mouse cecal mucus, and stimulated synthesis of both type 1 fimbriae and three E. coli F-18 Col- outer membrane proteins (74, 71, and 69 kDa). The 6.5-kb E. coli F-18 DNA sequence in pRLB7 does not contain either the fim operon or pilG (hns), both known to be involved in type 1 fimbrial synthesis. The sequence encodes six proteins, all smaller than the three E. coli F-18 Col- outer membrane proteins whose synthesis it stimulates. Collectively, the results suggest that the cloned E. coli F-18 DNA sequence contains one or more regulators of E. coli F-18 Col- operons expressed in the mouse large intestine in vivo and in isolated mouse cecal mucus in vitro.
Burghoff
R L
RL
Department of Microbiology, University of Rhode Island, Kingston 02881.
Pallesen
L
L
Krogfelt
K A
KA
Newman
J V
JV
Richardson
M
M
Bliss
J L
JL
Laux
D C
DC
Cohen
P S
PS
D000818:Animals; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D015139:Blotting, Southern; D002432:Cecum / Q000382:microbiology; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity / Q000648:ultrastructure; D010861:Fimbriae, Bacterial / Q000648:ultrastructure*; D005798:Genes, Bacterial; D015698:Genomic Library; D008297:Male; D051379:Mice; D009092:Mucous Membrane / Q000382:microbiology; D015183:Restriction Mapping; D013307:Streptomycin / Q000494:pharmacology
D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D013307:Streptomycin