TY  - JOUR
A1  - Knapp, S.
A1  - Hacker, Jörg
A1  - Jarchau, T.
A1  - Goebel, W
T1  - Large, Unstable Inserts in the Chromosome Affect Virulence
Properties Of Uropathogenic Escherichia coli 06 Strain 536
N2  - The hemolytic, uropathogenic Escherichia coli 536 (06:K15:H31) contains two inserts in its chromosome (insert I and insert II), both of which carried hly genes, were rather unstable, and were deleted spontaneously with a frequen~y of 10-3 to 10-4• These inserts were not found in the chromosome of two nonhemolytic E. coli strains, whereas the chromosomal ~equences adjacent to these inserts appeared tobe again homologous in the uropathogenic and two other E. coü strains. Insert I was 75 kilobases in size and was ftanked at both ends by 16 base pairs (bp) (TTCGACTCCTGTGATC) which were arranged in direct orientation. For insert I it was demonstrated that deletion occurred by recombination between the two 16-bp ftanking sequences, since mutants lacking this insert still carried a single copy of the 16-bp sequence in the chromosome. 8oth inserts contained a functional hemolysin determinant. However, the loss of the inserts not only atfected the hemolytic phenotype bot led to a considerable reduction in serum resistance and the loss of mannose-resistant hemagglutination, caused by the presence of S-type funbriae (sja). lt is shown that the Sfa-negative phenotype is due to a block in transcription of the sfa genes. Mutants of strain 536 which lacked both inserts were entirely avirulent when tested in several animal model systems.
KW  - Infektionsbiologie
Y1  - 1986
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/5245
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-59402
ER  -