Reduced virulence of a Listeria monocytogenes phospholipase-deficient mutant obtained by transposon insertion into the zinc metalloprotease gene.

Autor: Raveneau J; Faculté de Médecine Necker-Enfants Malades, Laboratoire de Microbiologie, Paris, France., Geoffroy C, Beretti JL, Gaillard JL, Alouf JE, Berche P
Jazyk: angličtina
Zdroj: Infection and immunity [Infect Immun] 1992 Mar; Vol. 60 (3), pp. 916-21.
DOI: 10.1128/iai.60.3.916-921.1992
Abstrakt: A phospholipase-deficient mutant, termed JL762, was obtained from a virulent strain of Listeria monocytogenes by screening a bank of 5,000 Tn1545 transposon-induced mutants on 2.5% egg yolk brain heart infusion agar. As previously shown (J. Mengaud, C. Geoffroy, and P. Cossart, Infect. Immun. 59:1043-1049, 1991), the transposon insertion took place inside the gene mpl, which encodes a zinc metalloprotease. By Western blot (immunoblot) analysis, we showed that loss of phospholipase activity was associated with loss of a 29-kDa zinc-dependent phosphatidylcholine-phospholipase C (PC-PLC) in culture supernatant of JL762 and of EGD-SmR incubated with ion chelator. As the parental strain, JL762 still produced in supernatants approximately 33-kDa proteins antigenically closely related to the 29-kDa PC-PLC. These results strongly suggest that the zinc metalloprotease of L. monocytogenes might play a role in the maturation of the 29-kDa PC-PLC. Although the uptake and the intracellular growth of bacteria were not affected in vitro, we found that the virulence of mutant JL762 was strongly impaired in the mouse.
Databáze: MEDLINE