Affiliation:
1. Istituto Cantonale di Microbiologia, Bellinzona, Switzerland
2. Health Protection Agency, Respiratory and Systemic Infection Laboratory, Centre for Infections, London, United Kingdom
3. Institute of Clinical Microbiology and Hygiene, Dresden, Germany
4. Centre National de Référence des Légionelles, INSERM E0230, Faculté de Médecine Laennec, IFR62, Lyon, France
Abstract
ABSTRACT
A previously described sequence-based epidemiological typing method for clinical and environmental isolates of
Legionella pneumophila
serogroup 1 was extended by the investigation of three additional gene targets and modification of one of the previous targets. Excellent typeability, reproducibility, and epidemiological concordance were determined for isolates belonging to both serogroup 1 and the other serogroups investigated. Gene fragments were amplified from genomic DNA, and PCR amplicons were sequenced by using forward and reverse primers. Consensus sequences are entered into an online database, which allows the assignment of individual allele numbers. The resulting sequence-based type or allelic profile comprises a string of the individual allele numbers separated by commas, e.g., 1,4,3,1,1,1, in a predetermined order, i.e.,
flaA
,
pilE
,
asd
,
mip
,
mompS
, and
proA
. The index of discrimination (
D
) obtained with these six loci was calculated following analysis of a panel of 79 unrelated clinical isolates. A
D
value of >0.94 was obtained, and this value appears to be sufficient for use in the epidemiological investigation of outbreaks caused by
L. pneumophila
. The
D
value rose to 0.98 when the results of the analysis were combined with those of monoclonal antibody subgrouping. Sequence-based typing of
L. pneumophila
is epidemiologically concordant and discriminatory, and the data are easily transportable. This consensus method will assist in the epidemiological investigation of
L. pneumophila
infections, especially travel-associated cases, by which it will allow a rapid comparison of isolates obtained in more than one country.
Publisher
American Society for Microbiology
Cited by
294 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献