Studies on Bacterial Aerosol Part 10 Species classification and antibiotic susceptibility of airborne staphylococci in hospital

• Published in: Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene) Vol. 39; no. 5; pp. 862 - 867
• Main Authors: Terayama, Kazuyuki, Hirata, Fumiko, Kawarabayashi, Tadao
• Format: Journal Article
• Language: English
• Published: The Japanese Society for Hygiene 30.12.1984
• Subjects: Airborne staphylococci in hospital; Antibiotics; Classification; Coagulase-negative staphylococci; Minimal inhibitory concentration; Multi-drug resistance
• ISSN: 0021-5082; 1882-6482; 1882-6482
• DOI: 10.1265/jjh.39.862

A new scheme for species-classification of staphylococci was applied to 124 strains of airborne staphylococci (A. S.) isolated from the air in hospital wards. For comparison, 204 strains of A. S. dispersed from healthy subjects and 521 strains of staphylococci isolated from their skin were also classified. In addition, both strains of A. S. in hospital wards and from the healthy subjects were tested for susceptibility to 11 major antibiotics (penicillin G, methicillin, cloxacillin, ampicillin, cephaloridine, erythromycin, chloramphenicol, streptomycin, tetracycline, kanamycin and gentamycin). The results obtained were as follows: 1. One of the 124 strains of A. S. from the hospital wards was identified as Staphylococcus aureus (S. aureus). The remaining 123 strains of coagulase-negative staphylococci (CNS) were classified into S. epidermidis (35.5%), S. haemolyticus (11.3%) and other species, except for 41 strains (33.1%) which were not classified. Most of the staphylococcal strains isolated from the healthy human skin were identified as S. epidermidis (82.0%). On the other hand, a large number of unclassifiable strains (76.5%) were observed in A. S. from the healthy subjects. 2. The airborne CNS strains from the hospital wards showed marked differences in minimal inhibitory concentration (MIC) for all antibiotics tested when compared to those from the healthy subjects. Particularly, half of them were resistant to penicillin G, methicillin, ampicillin and kanamycin. Similarly, the rate of airborne CNS strains in hospital wards was much higher for multi-drug resistance than those from the healthy subjects. The results suggest that some airborne CNS in hospital wards may act as opportunistic pathogens.