In:
Infection and Immunity, American Society for Microbiology, Vol. 70, No. 10 ( 2002-10), p. 5759-5769
Abstract:
Cytolysin A (ClyA) is a pore-forming cytotoxic protein encoded by the clyA gene that has been characterized so far only in Escherichia coli . Using DNA sequence analysis and PCR, we established that clyA is conserved in the human-specific typhoid Salmonella enterica serovars Typhi and Paratyphi A and that the entire clyA gene locus is absent in many other S. enterica serovars, including Typhimurium. The gene products, designated ClyA STy and ClyA SPa , show ≥90% amino acid identity to E. coli cytolysin A, ClyA EC , and they are immunogenically related. The Salmonella proteins showed a pore-forming activity and are hence functional homologues to ClyA EC . The chromosomal clyA STy gene locus was expressed at detectable levels in the serovar Typhi strains S2369/96 and S1112/97. Furthermore, in the serovar Typhi vaccine strain Ty21a, expression of clyA STy reached phenotypic levels, as detected on blood agar plates. The hemolytic phenotype was abolished by the introduction of an in-frame deletion in the clyA STy chromosomal locus of Ty21a. Transcomplementation of the mutant with a cloned clyA STy gene restored the hemolytic phenotype. To our knowledge, Ty21a is the first reported phenotypically hemolytic Salmonella strain in which the genetic determinant has been identified.
Type of Medium:
Online Resource
ISSN:
0019-9567
,
1098-5522
DOI:
10.1128/IAI.70.10.5759-5769.2002
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2002
detail.hit.zdb_id:
1483247-1
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