Auxiliary method for clonal identification of Staphylococcus aureus by protein band pattern of released proteins on SDS-polyacrylamide gel.

A supportive method for clonal identification of Staphylococcus aureus strains was devised. Culture supernatant obtained by cellophane surface culture was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without performing any concentration procedure prior to electrophoresis. The combined use of cellophane surface culture and SDS-PAGE was convenient for determining whether the strains belonged to the same clone or not when conducted in conjunction with other tests for bacteriological characterization.

Biochemical and genetic heterogeneity of staphylococcal protein A.

We investigated the biochemical and genetic heterogeneity of protein A from Staphylococcus aureus. SpA genes (spas) of various strains were heterogeneous when detected as DraI and EcoRV fragments of chromosomal DNA. Polymerase chain reaction using primers to detect DNA encoding the IgG-binding domains in spa revealed that they numbered between 2 and 5. Protein A from several S. aureus strains showed two types of reactivities to immunoglobulins in normal canine serum according to the number of active domains.

Efficient adsorption of lysostaphin on bacterial cells of lysostaphin-resistant Staphylococcus aureus mutant.

A simple and efficient method for the purification of staphylolytic endopeptidase (lysostaphin) contained in culture supernatant of Staphylococcus simulans biovar staphylolyticus strain by adsorption of the enzyme on bacterial cells of lysostaphin-resistant S. aureus mutant was successfully devised. Lysostaphin was sufficiently absorbed on the heat-killed mutant cells derived from S. aureus Cowan I and efficiently eluted by 3 M KSCN. Enzyme preparation obtained by a single procedure of the affinity purification was pure enough for practical use. The yield of the enzyme was 25 mg from 1 liter culture and recovery rate was 64%.

Relative risks of death due to liver disease among Japanese male adults having various statuses for hepatitis B s and e antigen/antibody in serum: a prospective study.

Taking advantage of the compulsory annual medical check-up at the Central Institute of Health, Japan National Railways, hepatitis B seromarkers were tested in male employees at work and their "dead and alive" status was followed for more than 6 years for their prognostic significance. Two prospective studies were carried out. In the first study, two groups (cohorts) of males age 40 to 55 years were tested in 1973 and 1978, respectively, for HBsAg and anti-HBs. The relative risk of dying from primary liver cancer in HBsAg-positive carriers (n = 126) as compared to the controls who were negative for both HBsAg and anti-HBs (n = 5,322) was 30.03 and significantly high, whereas those positive for anti-HBs (n = 1,470) had no increased risk of dying from primary liver cancer or from other liver diseases. The follow-up period ranged from 6.5 to 11.5 years, averaging 8.5 years. In the second study, three male cohorts of the same ages were tested for HBsAg and HBeAg/anti-HBe (micro-Ouchterlony method) in 1977, 1978 and 1979, respectively. There were 513 HBsAg-positive carriers among 25,547 examinees, who were followed for an average of 7.3 (6 to 8) years. Among these HBsAg carriers, those who were positive for HBeAg on entry had the highest risk of dying from primary liver cancer (relative risk, 50.25) and from other liver diseases (78.06), followed by those negative for both (28.95 and 21.78, respectively) and those positive for anti-HBe (9.47 and 6.43) when compared with 25,034 noncarriers.(ABSTRACT TRUNCATED AT 250 WORDS)