Restriction fragment length polymorphism in four virulence-associated genes of Listeria monocytogenes.
We observed restriction fragment length polymorphism in 4 genes of Listeria monocytogenes associated with virulence. Using the polymerase chain reaction (PCR) and primers derived from published sequences, we amplified the following genes: hlyA coding for listeriolysin O, iap coding for a putative invasion-associated factor, mpl coding for a metalloprotease, and the prfA gene that positively regulates the hylA gene. PCR-amplified DNA were cut with several restriction endonucleases, and the restriction profiles from 29 strains, representing 6 serovars (serovars 1/2a, 1/2b, 1/2c, 3a, 3b and 4b) were compared. Based on these restriction profiles, the strains were categorized into 2 subgroups: one group contained all 10 strains of serovars 1/2a, 1/2c and 3a, the other group contained all 19 strains of serovars 1/2b, 3b and 4b. This division is in complete agreement with multilocus enzyme electrophoretic analysis data which divide the species into the same 2 subgroups. Whether the differences observed in the nucleotide sequences of the 4 virulence-associated genes for the 2 subgroups of L. monocytogenes represent salient variations in pathogenic mechanisms is not known.
Vines
A
A
Department of Biology, Clark Atlanta University, GA 30314.
Reeves
M W
MW
Hunter
S
S
Swaminathan
B
B
D004269:DNA, Bacterial / Q000235:genetics; D004586:Electrophoresis; D005784:Gene Amplification / Q000235:genetics; D066298:In Vitro Techniques; D008089:Listeria monocytogenes / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D014774:Virulence / Q000235:genetics
D004269:DNA, Bacterial