Legionnaires' Disease associated with potting soil--California, Oregon, and Washington, May-June 2000.
(17/757)
Since Legionnaires' Disease (LD) was first reported in 1976, outbreaks have been associated with airborne transmission of Legionella bacteria through cooling towers, showers, and other aerosolizing devices (1). However, most LD cases are sporadic, and the source and mode of infection in many cases are unknown. Infections with one species, Legionella longbeachae, have been associated with gardening and use of potting soil in Australia and Japan (2,3). This report summarizes the findings of LD investigations in California, Oregon, and Washington, that suggest that transmission from potting soil has occurred for the first time in the United States, and that active surveillance and case finding are warranted to explore this association. (+info)
Occurrence and distribution of Legionella species in composted plant materials.
(18/757)
Legionellae were found in many samples of composted plant matter obtained from home gardeners and from facilities which undertook bulk composting. The predominant species isolated from these composts was Legionella pneumophila, the strains of which belonged to serogroups other than serogroup 1. Other Legionella species were present in many samples. Legionella longbeachae serogroup 1, which is implicated in human infections in South Australia, was present in samples obtained from two of six facilities composting large volumes of material and from 3 of 30 gardeners. Many of the species or strains isolated from composts have not been implicated as causative agents of legionellosis in South Austrailia, but some cause infection in healthy and immunosuppressed persons. (+info)
Rapid identification of clinically relevant Legionella spp. by analysis of transfer DNA intergenic spacer length polymorphism.
(19/757)
Analysis of PCR-amplified transfer DNA (tDNA) intergenic spacers was evaluated as a rapid method for identification to the species level of 18 species of Legionella known as human pathogens. Type strains (n = 19), reference strains (n = 16), environmental strains (n = 31), and clinical strains (n = 32) were tested. PCR products using outwardly directed tDNA consensus primers were separated on polyacrylamide gels and analyzed with automated laser fluorescence. Test results were obtained in 8 h starting with 72-h-old bacterial growth on solid medium. Species-specific patterns were obtained for all 18 Legionella species tested: Legionella anisa, L. bozemanii serogroups 1 and 2, L. cincinnatiensis, L. dumoffii, L. feeleii serogroups 1 and 2, L. gormanii, L. hackeliae serogroups 1 and 2, L. jordanis, L. lansingensis, L. longbeachae serogroups 1 and 2, L. lytica, L. maceachernii, L. micdadei, L. oakridgensis, L. parisiensis, L. pneumophila serogroups 1 to 14, L. sainthelensi serogroup 2, L. tucsonensis, and L. wadsworthii. Computer-assisted matching of tDNA-intergenic length polymorphism (ILP) patterns identified all 63 environmental and clinical strains to the species level and to serogroup for some strains. tDNA-ILP analysis is proposed as a routinely applicable method which allows rapid identification of environmental and clinical isolates of Legionella spp. associated with legionellosis. (+info)
Isolation of Legionella anisa using an amoebic coculture procedure.
(20/757)
Conventional diagnostic tests for legionellosis were negative for a 61-year-old immunocompromised man with pneumonia. However, coculture of a sputum sample with Acanthamoeba polyphaga amoebae led to the recovery of Legionella anisa. This procedure may be a sensitive and convenient diagnostic method, especially for non-Legionella pneumophila species infections that can be diagnosed only by culture. (+info)
Biochemical characterization of the FEZ-1 metallo-beta-lactamase of Legionella gormanii ATCC 33297T produced in Escherichia coli.
(21/757)
The bla(FEZ-1) gene coding for the metallo-beta-lactamase of Legionella (Fluoribacter) gormanii ATCC 33297T was overexpressed via a T7 expression system in Escherichia coli BL21(DE3)(pLysS). The product was purified to homogeneity in two steps with a yield of 53%. The FEZ-1 metallo-beta-lactamase exhibited a broad-spectrum activity profile, with a preference for cephalosporins such as cephalothin, cefuroxime, and cefotaxime. Monobactams were not hydrolyzed. The beta-lactamase was inhibited by metal chelators. FEZ-1 is a monomeric enzyme with a molecular mass of 29,440 Da which possesses two zinc-binding sites. Its zinc content did not vary in the pH range of 5 to 9, but the presence of zinc ions modified the catalytic efficiency of the enzyme. A model of the FEZ-1 three-dimensional structure was built. (+info)
A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden.
(22/757)
In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8% of 378 responders) aged 21-57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95% CI 21-352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71% (27/38) and 24 cases (83%) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools. (+info)
Legionella drozanskii sp. nov., Legionella rowbothamii sp. nov. and Legionella fallonii sp. nov.: three unusual new Legionella species.
(23/757)
Seven strains of Legionella-like amoebal pathogens (LLAPs) were characterized on the basis of their cultural and staining characteristics, biochemical reactions, serology, cellular fatty acids (CFAs), isoprenoid quinone composition, total DNA relatedness, analysis of 16S rRNA and macrophage infectivity potentiator (mip) gene sequence analyses. All seven strains exhibited limited growth on buffered charcoal yeast extract alpha (BCYE) agar, required cysteine for growth and contained branched-chain CFAs and quinones typical of Legionella species. The bacilli were Gram-negative and catalase-positive. There were varying degrees of serological cross-reactions between these LLAP strains and other previously described Legionella species. Results from the various tests revealed that four LLAP strains represent three unusual new species of Legionella: Legionella drozanskii sp. nov., type strain LLAP-1T; Legionella rowbothamii sp. nov., type strain LLAP-6T; and Legionella fallonii sp. nov., type strain LLAP-10T. Three other LLAP strains, designated LLAP-7FL, LLAP-7NF and LLAP-9, were shown to be members of the species Legionella lytica. The deductions made from the phenetic characteristics of these bacteria were consistent with the phylogenetic relationships inferred from 16S rRNA and mip gene sequence analyses. This study is the first to speciate LLAP strains on the basis of data including quantitative DNA hybridization. (+info)
Direct detection of Legionella species from bronchoalveolar lavage and open lung biopsy specimens: comparison of LightCycler PCR, in situ hybridization, direct fluorescence antigen detection, and culture.
(24/757)
We developed a rapid thermocycling, real-time detection (also known as real-time PCR) method for the detection of Legionella species directly from clinical specimens. This method uses the LightCycler (Roche Molecular Biochemicals, Indianapolis, Ind.) and requires approximately 1 to 2 h to perform. Both a Legionella genus PCR assay and Legionella pneumophila species-specific PCR assay were designed. A total of 43 archived specimens from 35 patients were evaluated, including 19 bronchoalveolar lavage (BAL) specimens and 24 formalin-fixed, paraffin-embedded open lung biopsy specimens. Twenty-five of the specimens were culture-positive for Legionella (9 BAL specimens and 16 tissue specimens). BAL specimens were tested by LightCycler PCR (LC-PCR) methods and by a direct fluorescent antibody (DFA) assay, which detects L. pneumophila serogroups 1 to 6 and several other Legionella species. Tissue sections were tested by the two LC-PCR methods, by DFA, by an in situ hybridization (ISH) assay, specifically designed to detect L. pneumophila, and by Warthin-Starry (WS) staining. The results were compared to the "gold standard" method of bacterial culture. With BAL specimens the following assays yielded the indicated sensitivities and specificities, respectively: Legionella genus detection by Legionella genus LC-PCR, 100 and 100%; Legionella genus detection by DFA assay, 33 and 100%; and L. pneumophila detection by L. pneumophila species-specific LC-PCR, 100 and 100%. With open lung biopsy specimens the following assays yielded the indicated sensitivities and specificities, respectively: Legionella genus detection by LC-PCR 68.8 and 100%; Legionella genus detection by DFA assay, 44 and 100%; Legionella genus detection by WS staining, 63 and 100%; L. pneumophila species-specific detection by LC-PCR, 17 and 100%; and L. pneumophila species-specific detection by ISH, 100 and 100%. The analytical sensitivity of both LC-PCR assays was <10 CFU/reaction. LC-PCR is a reliable method for the direct detection of Legionella species from BAL specimens. The Legionella genus LC-PCR assay could be performed initially; if positive, L. pneumophila species-specific LC-PCR could then be performed (if species differentiation is desired). The speed with which the LC-PCR procedure can be performed offers significant advantages over both culture-based methods and conventional PCR techniques. In contrast, for the methods evaluated, culture was the best for detecting multiple Legionella species in lung tissue. WS staining, Legionella genus LC-PCR, and L. pneumophila species-specific ISH were useful as rapid tests with lung tissue. (+info)