| Literature DB >> 1559006 |
T Meyer1, H Karch, J Hacker, H Bocklage, J Heesemann.
Abstract
Escherichia coli O157:H7 strains are newly recognized pathogens associated with haemorrhagic colitis and haemolytic-uremic syndrome. In addition to Shiga-like toxin types I and II known to be produced by E. coli O157 isolates, we have identified in E. coli O157:H7 strain 7279 a third toxin, designated SLT-IIvhc, that is neutralized neither by anti-SLT-I nor by anti-SLT-II antibodies. The genes for this toxin were isolated by using a PCR-mediated cell-free cloning technique. DNA sequence analysis revealed a high degree of homologies to SLT-II and several SLT-II variants. The predicted amino acid sequence of the A subunit of SLT-IIvhc differed from that of the O91:H7 toxin VT2ha and SLT-IIc from E. coli O157:H- strain E2511 by 2 and 3 amino acids, respectively. The amino acid sequence of its B subunit was identical to VT2ha and SLT-IIc but different from SLT-II and SLT-IIv. Immunological differences of SLT-IIvhc and SLT-II as well as their different toxicity to HeLa cells presumably resulted from the small deviations within the primary structure of the B subunit.Entities:
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Year: 1992 PMID： 1559006 DOI： 10.1016/s0934-8840(11)80004-6
Source DB: PubMed Journal: Zentralbl Bakteriol ISSN： 0934-8840