Author/Editor		Mandić-Mulec, Ines; Prohinar, Polona; Draškovič, Irena; Weiss, Jerrold
Title		Inaktivacija gena ompR poviša občutljivost bakterije Escherichia coli na antibiotik BPI
Translated title		ompR mutant of Escherichia coli shows increased sensitivity to the bactericidal/permeability-increasing protein (BPI)
Type		članek
Source		In: Bole-Hribovšek V, Ocepek M, Klun N, editors. Zbornik s programom 2. kongres slovenskih mikrobiologov z mednarodno udeležbo; 1998 sep 27-30; Portorož. Ljubljana: Slovensko mikrobiološko društvo,
Publication year		1998
Volume		str. 308-11
Language		slo
Abstract		Bactericidal/permeability-incrasing protein (BPI) is a polypeptide antibiotic acting selectively against Gram-negative bacteria. The recombinant 21 kD N-terminal fragment of BPI (BPI-21) is at least as active as holo-BPI. In the present study we examined effects of BPI-21 against the E. coli PL-2 strain in which the ompR gene has been inactivated by a Tn10 insertion. Our results show that a strain lacking the OmpR protein was more sensitive to BPI than the wild type E. coli. In addition, a smaller percentage of the BPI-21 treated ompR mutant was rescued by the addition of 0.1% albumine to the medium as compared to the wild type strain, suggesting that the mutant did not repair BPI inflicted damage as efficiently as the wild type strain. Interestingly, after exposure to sub-lethal concentrations of BPI-21 both strains showed a similar sensitivity to ActinomycinD and lost this sensitivity after removal of the surface bound BPI by 40mM Mg2+. Both strains also showed selective increase in LPS synthesis, which had been previously shown to be necessary for the repair of the outer membrane permeability barrier. Our observations suggest the repair of BPI induced damage in the presence of BSA is ompR dependent while the repair induced after the addition of Mg2+ is ompR independent.
Descriptors		ESCHERICHIA COLI CELL MEMBRANE PERMEABILITY BACTERIAL OUTER MEMBRANE PROTEINS MICROBIAL SENSITIVITY TESTS DACTINOMYCIN PORINS LIPOPOLYSACCHARIDES