Open AccessMutations affecting hemolysin production in Listeria monocytogenes located outside the listeriolysin gene
Author(s) -
LeimeisterWächter Michaela,
Goebel Werner,
Chakraborty Trinad
Publication year - 1989
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.1574-6968.1989.tb03591.x
Subject(s) - listeriolysin o , listeria monocytogenes , transposable element , biology , gene , hemolysin , gene cluster , microbiology and biotechnology , mutant , genetics , listeria , bacteria , virulence
We have investigated the molecular basis of spontaneous mutations leading to non‐hemolytic and avirulent variants of the Listeria monocytogenes serotype 1/2a strain NCTC 7973 using Southern hybridization to DNA fragments that harbor the listeriolysin gene ( hly A) and adjacent regions cloned from a L. monocytogenes serotype 1/2a strain. The analysis of such non‐hemolytic variants revealed the presence of a deletion of 300 base pairs, located 1.6 kb upstream of an otherwise intact listeriolysin gene. The importance of regions upstream of the hly A gene in controlling the expression of the listeriolysin gene was further emphasized by the detection of a transposon‐derived nonhemolytic mutant in which the transposon had inserted approximately 200 bp upstream of the listeriolysin gene. We conclude that at least two elements, contained within a region encompassing 1.6 kb of sequences upstream of the hly A gene, may be required for expression of the listeriolysin gene.