Bacterial Aerosol に関する研究

第2報 Impinger 法による空中細菌の分析

抄録

The airborne bacteria were investigated by the Impinger method and Koch's method in order to elucidate the significance of bacterial aerosol in ordinary living environments from the viewpoint of environmental medicine.
1. There was a correlation between the number of indoor airborne bacteria by the Impinger method and by Koch's method in the state after the students left the classroom, while there was no correlation during their stay in the room.
2. The number of bacteria after they left the room by the Impinger method was less than the number during their stay in the room.
3. The percentage of isolation of staphylococci from the indoor airborne bacteria by the Impinger method was about 15%.
4. In the airborne staphylococcus strains by the Impinger method, coagulase-positive strains were very few, while deoxyribonuclease-positive strains reached about 25%.
5. In deoxyribonuclease-positive strains of airborne staphylococci, alpha-lysin, beta-lysin and deltalysin by plate assay were found in a very high percentage, and in deoxyribonuclease-negative strains these hemolysin were also found.
The existence of pathogenic staphylococci in the indoor bacterial aerosol should be considered to be a valid indicator of carrier-borne bacterial contamination in living environments. These results indicate that the Impinger method would be adequate for the quantitative analysis of airborne bacteria, and both the hemolytic test by plate assay and the deoxyribonuclease test would be valuable as a screening test of pathogenic staphylococci.