A study on postoperative enteritis caused by methicillin-resistant Staphylococcus aureus.

We investigated the production of staphylococcal enterotoxin (SE) with respect to coagulase types by methicillin-resistant Staphylococcus aureus (MRSA). A total of 138 strains of MRSA, which were isolated from clinical materials in the surgical ward between 1983 and 1990, were studied. Coagulase type IV strains produced SE A only, whereas coagulase type II strains were classified into four groups by SE production: SE B producing strains (32.7%), SE C producing strains (29.8%), SE B and C coproducing strains (12.5%), and SE A and C coproducing strains (25.0%). Almost all of the organisms (nine of ten) which were isolated from the feces of patients with MRSA enteritis were SE A and C coproducing strains. The coincidence in time of the prevalence of MRSA enteritis and the isolation SE A and C coproducing strains also demonstrated that these strains caused MRSA enteritis. Although SE C producing strains and SE A and C coproducing strains were simultaneously prevalent in 1990, the former tended to be sensitive while the latter tended to be resistant to minocycline. Considering the variety of antibiotic sensitivity in coagulase type II strains, it is thus considered to be of critical importance for epidemiologic purposes to further characterize isolates by SE typing.