Spatial variation of airborne bacterial heterogeneity and potential opportunistic human pathogens: a comparative study of sites in Korea and Japan

Biological particles known as bioaerosols are present in the atmosphere and have recently been implicated as influencing agriculture, cloud development, biogeography, and human health. The present study was conducted to characterize airborne bacterial heterogeneity at Jeju Island in Korea and at Saitama and Toyama in Japan, focusing on potential human pathogens. Air samples were collected during the winter, when the monsoon blows from the northwest. Samples were analyzed by high-throughput sequencing and denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA genes to detect spatial differences in airborne bacteria and the possible spread of bacteria by transboundary transport. Compositions of the bacterial in samples collected on the same dates from the different sites were similar. Notably, bacteria from two genera that are potentially pathogenic for humans—Acinetobacter and Clostridium—were detected on the same day in both Korea and Japan. These results indicate the possibility of long-range transport of airborne bacteria and its potential impact on human health.