[Polymerase chain reaction associated with dig-labelled DNA hybridization of mip gene to identify new isolated Legionella pneumophila strains].
OBJECTIVE
By testing mip gene, one highly conservative virulence gene of Legionella pneumophila (Lp), as targets of polymerase chain reaction (PCR) and Digoxin-labelled probe hybridization to establish a rapid, specific and sensitive gene analysis method that can identify new isolated suspected bacteria strains as Lp.


METHODS
Abstracting all the CDC reference Lp strains' and none-Lp Legionella strains' DNA, as well as the domestic isolated Lp strains' and some non-Legionella control bacteria's DNA as templates, then were processed. All the positive PCR products(if no PCR amplicons were available, the original whole DNA should be detected) were hybridized with Digoxingen-labelled mip gene probe in dot-blot procedure.


RESULTS
All the tested Lp strains had positive PCR and hybridization results, at the same time, all none-Legionella bacteria and none-Lp Legionella strains got negative results. 6 of 26 isolates were identified as Lp strains by this method.


CONCLUSIONS
Such a Lp strain identification procedure shows high specificity and sensitivity (nearly 100%, in this study), and mean-while can be completed in a relative short time. Surely, this method can be largely available and has a potential value in diagnosis of clinical Legionellosis cases and pursuing the pathogen during Legionnaires' disease outbreaks.
Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing 102206.
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Lu
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Peng
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Ren
D001426:Bacterial Proteins; D004269:DNA, Bacterial / Q000032:analysis*; D005798:Genes, Bacterial; D020104:Immunophilins / Q000235:genetics*; D016952:Legionella pneumophila / Q000235:genetics / Q000302:isolation & purification*; D008565:Membrane Proteins / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D019696:Peptidylprolyl Isomerase; D016133:Polymerase Chain Reaction
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D020104:Immunophilins; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase