Abstract
Isolation patterns and drug susceptibilities of Staphylococcus aureus and Staphylococcus epidermidis were investigated in Kashima Rosai Hospital, a local hospital with 300 beds opened in June, 1981. Our investigation covered 218 Staphylococcus strains isolated from various clinical materials in the Clinical Laboratory during a one year period in 1985.
These isolated strains comprised of 8 species of genus Staphylococcus with S. aureus and S. epidermidis together accounted for 93.6% of all the clinically isolated Staphylococci. S. aureus was detected in materials obtained from outpatients at a higher frequency than S. epidermidis, while the opposite was the case in materials obtained from inpatients. When distributions of these organisms were classified depending on clinical materials from which they were isolated, outpatient sources from which S. aureus were isolated at high frequencies were otorrhea and pus, while inpatient sources with high incidents of S. aureus isolation were sputum and pus. With regards to S. epidermidis, urine and pus from outpatients as well as from inpatients yielded this organism at high frequencies.
Isolation frequency ratios in this hospital of methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE) were 8.6% and 30.8%, respectively. These resistant strains were found from a large spectrum of clinical materials. Thus, these strains seemed to have established themselves more or less firmly among bacterial population in the hospital, hence alerting us the risk of hospital infections in compromised hosts. As to the coagulase typing of MRSA, type IV was the most frequent from outpatient sources whereas type II was the most frequent from inpatient sources including a large variety of clinical materials. The coagulase typing has been regarded as useful in epidemiological surveys of nosocomial infections, and as more expedient and rapid than the phage typing. We confirmed these in our investigation.
Among beta-lactam antibiotics we tested against MRSA, flomoxef was found to be superior to the others. Cephalothin and cefamandole proved to be highly active against MRSE. Minocycline and vancomycin showed good activities against MRSE as well as MRSA.
