FEMS Immunology and Medical Microbiology 6 (1993) 331-340 © 1993 Federation of European Microbiological Societies 0920-8534/93/$06.00 Published by Elsevier 331 FEMSIM 00318 Heat-labile and heat-stable haemolysins of Campylobacter jejuni A. Hossain, D.E.S. Stewart-Tull and J.H. Freer Department of Microbiology, Universityof Glasgow, Glasgow, UK (Received 15 November 1992; accepted 22 December 1992) Abstract: During studies on the virulence mechanisms of Campylobacterjejuni clinical isolates it became apparent that some strains produced one or more haemolysins and some did not. There was no great difference between Group C (cholera-like) strains and Group D (dysentery-like) strains. The protein haemolysin(s) showed a spectrum of activity against erythrocytes from different animals; with maximum activity against rabbit and minimal activity against chicken erythrocytes. The results suggested a two-stage activation mechanism for haemolysis which involved a multi-hit lytic activity. It was concluded that the C. jejuni haemolysins were not identical to those described in other organisms and they may be involved in iron acquisition in vivo. Key words: Heat-labile haemolysin; Heat-stable haemolysin; Campylobacterjejuni Introduction Campylobacter jejuni has a global distribution and is a major cause of enteric disease in humans [1,2]. Recent pathogenicity studies showed that some diarrhoeal strains of C. jejuni produce a cytotoxin either singly or along with a cytotonic toxin [3]. Other phenomena attributed to the pathogenesis of C. jejuni are colonisation and invasion of gut mucosa [4-9]. The interplay of the various virulence determinants of the pathogen in the disease process is unclear, but bacteraemia, infiltration and destruction of gut epithelial cells resulting in bloody diarrhoea indicates that a cytolytic process plays a part. Correspondence to. D.E.S. Stewart-Tull. Department of Microbiology, University of Glasgow, Glasgow G12 8QQ, UK. While investigating different aspects of C. je- juni pathogenesis, it was observed that culture fluids of a number of strains lysed rabbit erythro- cytes: a C. jejuni haemolysin(s) and the properties associated with it is re~orted. Materials and Methods Bacterial strains A total of 15 clinical isolates of C. jejuni were obtained; 7 were isolated at the International Centre for Diarrhoeal Disease Research, Bangla- desh (prefix B) and 8 were isolated in Scotland (prefix S). Strains $9, $13, $14 and $15 were isolated from patients with cholera-like, watery diarrhoea (Group C) and strains Sll and S12 were isolated from patients with dysentery-like bloody, mucoid diarrhoea (Group D). Detailed clinical histories for the remaining strains were Downloaded from https://academic.oup.com/femspd/article-abstract/6/4/331/537886 by guest on 15 June 2020