In:
Clinical and Vaccine Immunology, American Society for Microbiology, Vol. 20, No. 5 ( 2013-05), p. 712-719
Abstract:
Salmonella enterica serotype Paratyphi A is a human-restricted pathogen and the cause of paratyphoid A fever. Using a high-throughput immunoscreening technique, in vivo -induced antigen technology (IVIAT), we identified 20 immunogenic bacterial proteins expressed in humans who were bacteremic with S . Paratyphi A but not those expressed in S . Paratyphi A grown under standard laboratory conditions. The majority of these proteins have known or potential roles in the pathogenesis of S. enterica . These include proteins implicated in cell adhesion, fimbrial structure, adaptation to atypical conditions, oxidoreductase activity, proteolysis, antimicrobial resistance, and ion transport. Of particular interest among these in vivo -expressed proteins were S . Paratyphi A (SPA)2397, SPA2612, and SPA1604. SPA2397 and SPA2612 are prophage related, and SPA1604 is in Salmonella pathogenicity island 11 (SPI-11). Using real-time quantitative PCR (RT-qPCR), we confirmed increased levels of mRNA expressed by genes identified by IVIAT in a comparison of mRNA levels in organisms in the blood of bacteremic patients to those in in vitro cultures. Comparing convalescent- to acute-phase samples, we also detected a significant increase in the reaction of convalescent-phase antibodies with two proteins identified by IVIAT: SPA2397 and SPA0489. SPA2397 is a phage-related lysozyme, Gp19, and SPA0489 encodes a protein containing NlpC/P60 and cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domains. In a previous study utilizing a different approach, we found that transcripts for 11 and 7 of the genes identified by IVIAT were detectable in organisms in the blood of humans in Bangladesh who were bacteremic with S . Paratyphi A and Salmonella enterica serovar Typhi, respectively. S. Paratyphi A antigens identified by IVIAT warrant further evaluation for their contributions to pathogenesis and might have diagnostic, therapeutic, or preventive relevance.
Type of Medium:
Online Resource
ISSN:
1556-6811
,
1556-679X
DOI:
10.1128/CVI.00054-13
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2013
detail.hit.zdb_id:
1496863-0
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