Tn916-induced mutations in the hemolysin determinant affecting virulence of Listeria monocytogenes
نویسندگان
چکیده
منابع مشابه
Mutations affecting hemolysin production in Listeria monocytogenes located outside the listeriolysin gene.
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 (hlyA) and adjacent regions cloned from a L. monocytogenes serotype 1/2a strain. The analysis of such non-hemolytic variants revealed the pre...
متن کاملVirulence testing of Listeria monocytogenes.
A major problem in understanding foodborne listeriosis from both the basic science and regulatory perspectives revolves around the role played by virulence factors of Listeria monocytogenes and how these interact with host susceptibility to result in the observed incidence of disease. From a mechanistic perspective, this problem has been well investigated, and many virulence components of L. mo...
متن کاملDetection of listeriolysin, the thiol-dependent hemolysin in Listeria monocytogenes, Listeria ivanovii, and Listeria seeligeri.
The listeriolysin gene from a weakly hemolytic but virulent strain of Listeria monocytogenes serotype 1/2a was cloned in Escherichia coli K-12. Recombinants were identified on the basis of their cross-reactivities to hyperimmune antisera raised against streptolysin O and listeriolysin. Low levels of hemolytic activity were detected in crude lysates of strains harboring the listeriolysin gene. I...
متن کاملRole of hemolysin for the intracellular growth of Listeria monocytogenes
Listeria monocytogenes insertion mutants defective in hemolysin production were generated using the conjugative transposons Tn916 and Tn1545. All of the nonhemolytic mutants (hly-) lacked a secreted 58-kD polypeptide, presumedly hemolysin, and were avirulent in a mouse model. An intracellular multiplication assay was established in monolayers of mouse bone marrow-derived macrophages, the J774 m...
متن کاملCardiotoxic and Lethal Effects of Listeria monocytogenes Hemolysin.
Cardiotoxic and lethal effects of Listeria monocytogenes hemolysin were studied in CD-1 mice injected with varying doses of hemolysin. Intravenous injection of 100 complete hemolytic units (CHU) caused 100% lethality within 4 to 5 min. Doses ranging from 40 to 50 CHU caused death of approximately 50% of the animals. Adrenergic blocking agents and antihistamine failed to protect mice against let...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1987
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.169.3.1291-1297.1987