Open AccessAdaptation of signature‐tagged mutagenesis to Escherichia coli K1 and the infant‐rat model of invasive disease
Author(s) -
Gonzalez Mark D.,
Lichtensteiger Carol A.,
Vimr Eric R.
Publication year - 2001
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2001.tb10630.x
Subject(s) - virulence , biology , transposon mutagenesis , mutagenesis , escherichia coli , gene , mutant , microbiology and biotechnology , genetics , transposable element
With the exception of the polysialic acid capsule (K1 antigen), little is known about other virulence factors needed for systemic infection by Escherichia coli K1, the leading cause of Gram‐negative neonatal meningitis in humans. In this work, the functional genomics method of signature‐tagged mutagenesis (STM) was adapted to E. coli K1 and the infant‐rat model to identify non‐capsule virulence genes. Validation of the method was demonstrated by the failure to recover a reconstructed acapsular mutant from bacterial pools used to systemically infect 5‐day‐old rats. Three new genes required for systemic disease were identified from a total of 192 mutants screened by STM (1.56% hit rate). Gut colonization, Southern blot hybridization, mixed‐challenge infection, and DNA sequence analyses showed that the attenuating defects in the mutants were associated with transposon insertions in rfaL (O antigen ligase), dsbA (thiol:disulfide oxidoreductase), and a new gene, puvA ( p reviously u nidentified v irulence gene A ), with no known homologues. The results indicate the ability of STM to identify novel systemic virulence factors in E. coli K1.