RT Journal Article SR Electronic(1) A1 Eberspacher, B. A1 Hugo, F. A1 Pohl, M. A1 Bhakdi, S.YR 1990 T1 Functional similarity between the haemolysins of Escherichia coli and Morganella morganii JF Journal of Medical Microbiology, VO 33 IS 3 SP 165 OP 170 DO https://doi.org/10.1099/00222615-33-3-165 PB Microbiology Society, SN 1473-5644, AB Surmmary Haemolysin produced by a clinical isolate of Morganella morganii was examined for antigenic relatedness to the haemolysin of Escherichia coli and for similarities in mode of action. The M. morganii haemolysin migrated in SDS-PAGE as a single protein band with a slightly higher molecular weight than that of E. coli haemolysin. Several murine monoclonal antibodies against E. coli haemolysin cross-reacted with the M. morganii haemolysin in Western blots. Diminished haemolysis in the presence of osmotically-stabilising solutes indicated the formation of a pore by M. morganii haemolysin with an effective diameter of 1.5–3 nm. Results from dose-response experiments indicated that a single hit was sufficient for lysis of an erythrocyte. Detergent solubilisation of toxin-treated membranes led to recovery of bound toxin exclusively in monomeric form. M. morganii haemolysin was a potent leucocidin, that caused rapid leakage of ATP and death of human polymorphonuclear leucocytes. Under in-vitro conditions M. morganii haemolysin displayed similar leucocidal and haemolytic efficiency. The data demonstrate that M. morganii haemolysin shows functional properties virtually identical with those of E. coli haemolysin., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-33-3-165