1987 Volume 12 Issue 3 Pages 289-302
Coagulase-negative staphylococcus (C-NS) seems to be one of the pathogenic bacteria in opportunistic infections. Of 315 strains, 157 strains of C-NS were isolated from inpatients and from healthy persons used as controls to study on their bacteriological characteristics. Staphylococcus epidermidis was isolated from most of them (89.8%). It produced an elastolytic enzyme that seemd to be a pathogenic factor in their infections. Elastolytic ennzyme was detected by a bacteriological and biochemical analysis, in 68.8% of S. epidermidis.
The enzyme from S. epidermidis was partially purified by using two assays: Sephadex G-100gel chromatography and CM-Toyopearl ion exchange chromatography. The results were; (1)the elastolytic enzyme hydrolyzed porcine elastin and Suc-(Ala)3-PNA, (2)molecular weight was found to be 22,500, (3)the isoelectric point was betweem 9.4 and 9.5, (4)characteristics of the elastolytic enzyme indicated that there is a similarity to that of thiol protease, however, they were different from those of other elastases.
Four guinea pigs were given an intracutaneous injection of the elastolytic enzyme to detect the pathogenic mechanism of the enzyme. Deep ulceration and abscesses were observed in the skin of the back. These histopathological findings indicate that the enzyme is deeply associated with the pathogenicity of C-NS.
