RESUMO
Legionella pneumophila is the major causative agent of Legionnaires' disease. The distribution of L. pneumophila in environmental water systems of public facilities in Busan, South Korea was previously reported; however, the distribution of virulence genes in environmental and clinical isolates in Busan is unknown. Here, we investigated using PCR the distribution of three virulence loci (dot/icm, lvh, and rtxA) in isolates from Busan. A high prevalence of environmental (127/254) and clinical (3/4) isolates were observed for the simultaneous presence of all three genes, while environmental harboring dot/icm + rtxA, dot/icm + lvh, rtxA + lvh, and only one gene were 21%, 11%, 9% and <1-4%, respectively, The remaining clinical isolate carried dot/icm + rtxA. In addition, 68% of isolates from serogroup 1, the main cause of legionellosis, possessed all three virulence genes compared with 40% of isolates from serogroups 2 to 15. Prevalence of isolates with two genes was 5-14% and 6-29% in serogroup 1 and serogroups 2 to 15, respectively, whereas that of isolates with one gene was 1-2% and 0-6%, respectively. These results provide valuable information for epidemiological investigations of the relationship between environmental and clinical isolates in legionellosis outbreaks in Busan.