1887

Abstract

The biochemical, immunological, and biological properties of an S layer purified from an strain (AH-342) involved in a case of bacteraemia were investigated. The S layer selectively removed from the cell surface was composed of a single acidic (pI 4·65) protein subunit (surface array protein, SAP) with a molecular mass of approximately 52 kDa. Amino acid analysis of this 52 kDa protein indicated a molecule composed of 498 amino acids with 46% hydrophobic residues. No cysteine residues were detected. The first 35 residues of the N-terminus were sequenced by Edman degradation; only 4–24% homology was noted between this sequence and those previously published for SAPs of (A450) and a strain of (TF7) originally isolated from a moribund fish. Polyclonal antibodies raised against AH-342 SAP were genospecific, reacting only against S layers produced by strains and not those from . Acute serum from the bacteraemic patient from whom AH-342 was isolated reacted strongly with the SAP of AH-342 in immunoblot studies. Purified SAP, when intraperitoneally co-inoculated with SAP strains of into Swiss-Webster mice, could reduce the 50% lethal dose by approximately 30–70 fold. The results suggest that the SAP of strains may play an important role in systemic dissemination after invasion through the gastrointestinal mucosa.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-138-6-1229
1992-06-01
2019-10-22
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-138-6-1229
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error