Nosocomial Legionnaires' disease caused by Legionella pneumophila serogroup 6: implication of the sequence-based typing method (SBT).

Sequence-based typing (SBT) was used to determine the allelic profiles of 3 sporadic clinical isolates as well as 7 environmental isolates of Legionella pneumophila serogroup 6, isolated at the Karolinska Hospital during 2004. The clinical isolates were cultured from patients with nosocomial Legionnaires' disease (LD), while the environmental isolates were cultured from potable water sources of the hospital wards in the close vicinity of the 3 patients being investigated. The genes sequenced for the construction of the SBT profile included flaA, pilE, asd, mip, mompS and proA, in this pre-determined order and the allelic profile of the 10 isolates was identical (3, 13, 1, 28, 14, 9).

Whole cell protein and partial 16S rRNA gene sequence analysis suggest the existence of a second Rothia species.

OBJECTIVE: To subject ten clinical isolates grouped together based on their biochemical and microbiological profile to further investigations aimed at correct species identification. METHODS: The 16S rRNA gene was partially sequenced using nested amplification. Whole cell protein analysis (SDS-PAGE) and cluster analysis were performed on the 10 strains and also for comparison on 31 reference strains.

A nested polymerase chain reaction for detection of Legionella pneumophila in clinical specimens.

OBJECTIVE: Because presently used methods for diagnosis of Legionella pneumonia lack sufficient sensitivity and sometimes specificity and rapidity, the detection of Legionella spp. by amplification of nucleic acids might be valuable. However, performing polymerase chain reaction (PCR) on clinical samples such as sputum is difficult because of the presence of extraneous DNA and inhibitors of the reaction.