Distribution of 19 major virulence genes in Legionella pneumophila serogroup 1 isolates from patients and water in Queensland, Australia.
The distribution of 19 major virulence genes and the presence of plasmids were surveyed in 141 Legionella pneumophila serogroup (SG) 1 isolates from patients and water in Queensland, Australia. The results showed that 16 of the virulence genes examined were present in all isolates, suggesting that they are life-essential genes for isolates in the environment and host cells. The 65 kb pathogenicity island identified originally in strain Philadelphia-1(T) was detected more frequently in isolates from water (44.2%) than in those from patients (2.7%), indicating that the 65 kb DNA fragment may aid the survival of L. pneumophila in the sampled environment. However, the low frequency of the 65 kb fragment in isolates from patients suggests that the pathogenicity island may not be necessary for L. pneumophila to cause disease. Plasmids were not detected in the L. pneumophila SG1 isolates from patients or water studied. There was an association of both lvh and rtxA with the virulent and predominant genotype detected by amplified fragment length polymorphism, termed AF1, whereas the avirulent common isolate from water termed AF16 did not have lvh or rtxA genes, with the exception of one isolate with rtxA. It was found that a PCR detection test strategy with lvh and rtxA as pathogenesis markers would be useful for determining the infection potential of an isolate.
Huang
Bixing
B
Public Health Microbiology Laboratory, Queensland Health Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
Yuan
Zheng
Z
Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia.
Heron
Brett A
BA
Public Health Microbiology Laboratory, Queensland Health Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
Gray
Bruce R
BR
Public Health Microbiology Laboratory, Queensland Health Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
Eglezos
Sofroni
S
EML Consulting Services Queensland Pty Ltd, 1/148 Tennyson Memorial Avenue, Tennyson, QLD 4105, Australia.
Bates
John R
JR
Public Health Microbiology Laboratory, Queensland Health Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
Savill
John
J
Public Health Microbiology Laboratory, Queensland Health Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
D001315:Australia; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D044404:Genomic Islands / Q000235:genetics; D006801:Humans; D016952:Legionella pneumophila / Q000235:genetics* / Q000472:pathogenicity; D007877:Legionnaires' Disease / Q000453:epidemiology / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014774:Virulence / Q000235:genetics; D014871:Water Microbiology
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005819:Genetic Markers; C459580:Lvh protein, Legionella pneumophila; C434464:RtxA protein, Vibrio cholerae