Characterization of Legionella pneumophila isolates from patients in Japan according to serogroups, monoclonal antibody subgroups and sequence types.
We collected 86 unrelated clinical Legionella pneumophila strains that were isolated in Japan during the period 1980-2008. Most (80.2%) belonged to serogroup 1, followed by serogroups 5, 3 and 2. Interestingly, the patients with L. pneumophila serogroup 1 had a significantly higher male-to-female ratio (12.4) than the patients with other L. pneumophila serogroups (2.0) (OR, 10.5; 95% CI, 2.5-44.5). When the serogroup 1 strains were analysed by monoclonal antibody (mAb) typing, the most prevalent subgroup was Benidorm (34.9% of all isolates). Moreover, 79.7% of the serogroup 1 isolates were bound by mAb 3/1, which recognizes the virulence-associated epitope. When all 86 isolates were subjected to sequence-based typing (SBT) using seven loci, they could be divided into 53 sequence types (STs). The ST with the most isolates (seven) was ST1, to which most isolates from patients and environments around the world belong. However, six of the seven ST1 isolates were isolated before 1994. Other major STs were ST306 (n=6), ST120 (n=5) and ST138 (n=5). All ST306 and ST138 isolates, except for one isolate (ST306), were suspected or confirmed to be derived from bath water, which suggests that these strains prefer bath habitats. The sources of all ST1 and ST120 isolates remain unclear. By combining the SBT and mAb data, the 86 isolates could be divided into 59 types (discrimination index, 0.984). This confirms the usefulness of this combination in epidemiological studies.
Amemura-Maekawa
Junko
J
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
Kura
Fumiaki
F
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
Helbig
Jürgen H
JH
Institute of Medical Microbiology and Hygiene, TU Dresden, Dresden, Germany.
Chang
Bin
B
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
Kaneko
Akiko
A
Yamagata Prefectural Institute of Public Health, Yamagata, Japan.
Watanabe
Yuko
Y
Kanagawa Prefectural Institute of Public Health, Kanagawa, Japan.
Isobe
Junko
J
Toyama Institute of Health, Toyama, Japan.
Nukina
Masafumi
M
Public Health Research Institute of Kobe City, Hyogo, Japan.
Nakajima
Hiroshi
H
Okayama Prefectural Institute for Environmental Science and Public Health, Okayama, Japan.
Kawano
Kimiko
K
Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki, Japan.
Tada
Yuki
Y
Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan.
Watanabe
Haruo
H
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
The Working Group For In Japan
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D016952:Legionella pneumophila / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D017422:Sequence Analysis, DNA; D012703:Serotyping; D055815:Young Adult
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D004269:DNA, Bacterial