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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Legionella pneumophila, a Gram-negative bacterium, is the causative agent of legionellosis. Traditionally, culture methods are normally used to detect Legionella species in different types of water (e.g. surface or tap water, circulating systems, air conditioners and their cooling devices). In this study the PCR conditions to detect Legionella were optimised based on the EnviroAmp Legionella kit (Perkin-Elmer) which is no longer commercially available. The PCR is very sensitive and specific in indicating the presence or absence (no quantification with classical PCR) of Legionella spp in general and more specifically L. pneumophila. To identify L. pneumophila. DNA sequences from the mip (macrophage infectivity potentiator) gene were amplified. The mip gene is conserved and specific for L. pneumophila although mip-like genes are also present in other Legionella spp. The PCR techniques were able to detect small amounts of Legionella in tap water samples. Cooling water, however, often contained PCR-inhibiting substances that could result in false negative PCR results for Legionella.
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PMID:PCR as a test for the presence or absence of Legionella in (cooling) water. 1263 13

The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.
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PMID:Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens. 1558 39

This study describes the development and evaluation of a new commercial test, Chlamylege (Argene Inc.), which allows the simultaneous detection in respiratory samples of Chlamydophila pneumoniae, Mycoplasma pneumoniae, and most Legionella species, as well as PCR inhibitors, by using a multiplex PCR and microplate hybridization. The sensitivities of Chlamylege were 1 x 10(-3) IFU, 5 x 10(-2) color-changing units, and 1 CFU per reaction tube for C. pneumoniae, M. pneumoniae, and Legionella pneumophila, respectively. A cohort of 154 clinical samples from patients with documented respiratory infections was analyzed by the kit, including 2 samples from patients with C. pneumoniae infection, 9 samples from patients with M. pneumoniae infection, 19 samples from patients with Legionella species infection, and 114 samples that tested negative for the three pathogens. All the positive specimens were correctly detected and identified by the Chlamylege kit, and no false-positive result was observed with the negative samples. The kit was then evaluated in a pediatric prospective study that included 220 endotracheal aspirates, and the results were compared with those obtained by three single in-house PCR assays. Four specimens were found to be positive for C. pneumoniae and six were found to be positive for M. pneumoniae by using both strategies. The Chlamylege kit detected two additional samples positive for M. pneumoniae and one additional sample positive for a Legionella species other than L. pneumophila; these three samples were shown to be true positive by other techniques. These overall results demonstrate that the Chlamylege assay is sensitive, specific, and convenient for the rapid detection and identification of atypical pathogens in clinical samples from patients with respiratory infections.
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PMID:Development and evaluation of Chlamylege, a new commercial test allowing simultaneous detection and identification of Legionella, Chlamydophila pneumoniae, and Mycoplasma pneumoniae in clinical respiratory specimens by multiplex PCR. 1600 Apr 43

During an outbreak of legionellosis in Belgium, urine samples of 32 legionellosis patients were tested with three Legionella urinary antigen assays: the Biotest enzyme immunoassay (EIA) kit, the Binax EIA kit and the Binax NOW Immunochromatographic Test kit. The three tests were concomitantly compared. The test sensitivities on the first urine samples were 65.6 % for the Biotest EIA, 50.0 % for the Binax EIA and 56.3 % for the Binax NOW. Testing of a second urine sample increased the sensitivities to 71.9 %, 59.4 % and 65.6 %, respectively. The differences were not statistically significant. In outbreak settings, testing second samples from patients presenting with symptoms but initially testing negative and/or concentrating urine samples for testing might be valuable additions to the urinary antigen test to increase the sensitivities of the tests.
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PMID:Comparison of three Legionella urinary antigen assays during an outbreak of legionellosis in Belgium. 1627 36

A 77-year-old man who had fever and chest pain was admitted to a neighboring hospital on a diagnosis of pneumonia. Chest X-ray film finding deteriorated despite treatment with 2 g cefotaxime per day. Because of accompanying acute renal failure, he was transferred to our hospital. Hemodialysis with intravenous administration of erythromycin and meropenem resulted in recovery from acute renal failure, and his general condition improved. Because of liver dysfunction, erythromycin was changed to pazufloxacin. Although he was negative for Legionella urinary antigen determined with a rapid assay kit, Binax NOW, his serum titer for Legionella pneumophila serogroup 4 was elevated. Finally, a diagnosis of Legionnaires' disease caused by Legionella pneumophila serogroup 4 was established.
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PMID:[Legionnaires' disease with acute renal failure caused by Legionella pneumophilla serogroup 4]. 1636 67

In this study, real-time PCR with pathogen-specific molecular beacons (MB) and primers was evaluated for prediction of community-acquired pneumonia (CAP) causative agents, detecting six main CAP agents, Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, and Streptococcus pyogenes, simultaneously. The PCR assay was evaluated for fresh clinical specimens from infants and children (n = 389) and from adults (n = 40). The MB probes and primers are both pathogen specific, namely, the lytA gene for S. pneumoniae, the mip gene for L. pneumophila, and 16S rRNA genes for the remaining four organisms. DNA extraction of clinical specimens was performed with a commercially available EXTRAGEN II kit, and amplification was performed with Stratagene Mx3000P. The limit of detection for these pathogens ranged from 2 copies to 18 copies. The whole process from DNA extraction to the analysis was finished in less than 2 h. The obtained sensitivity and specificity of this real-time PCR study relative to those of conventional cultures were as follows: 96.2% and 93.2% for S. pneumoniae, 95.8% and 95.4% for H. influenzae, 100% and 100% for S. pyogenes, and 100% and 95.4% for M. pneumoniae, respectively. The sensitivity and specificity for M. pneumoniae relative to those of a serologic assay were 90.2% and 97.9%, respectively. In six clinical samples of C. pneumoniae, the real-time PCR gave positive predictable values, and in those cases, elevation of the titer value was also observed. In conclusion, we demonstrated that a real-time PCR assay with pathogen-specific MB is useful in identifying CAP causative agents rapidly and in examining the clinical course of empirical chemotherapy in a timely manner, supporting conventional culture methods.
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PMID:Simultaneous detection of pathogens in clinical samples from patients with community-acquired pneumonia by real-time PCR with pathogen-specific molecular beacon probes. 1659 74

Despite major improvements in the diagnosis of pathogenic organisms causing acute respiratory infections (ARIs), details of infections caused by atypical pathogens are not well understood, particularly in developing countries. This clinical and epidemiological research was conducted in Bangladesh to explore the prevalence of atypical pathogens in causing childhood pneumonia. Sixty-four children with ARI were studied at the Pediatric Outpatient Department of Dhaka Medical College Hospital, Bangladesh, during September through December 2000. In addition to clinical examination, hematological, radiological, and bacteriological examinations were performed. Antibody titers from paired sera against Mycoplasma pneumoniae and Legionella spp. in the acute and convalescent phases revealed that none of these children were infected with M. pneumoniae, while only one serum sample was positive for L. pneumophila serogroup 4. Antibody titers against Chlamydophila (Chlamydia) pneumoniae, determined by an indirect microimmunofluorescence method, and by an enzyme-linked immunosorbent assay (ELISA) kit (HITAZYME C. pneumoniae kit) indicated that 13 children (20.3%) were infected with C. pneumoniae. Our results indicate a high prevalence rate of C. pneumoniae, suggesting it is as an important causative pathogen of childhood pneumonia in Bangladesh.
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PMID:Prevalence of Chlamydophila pneumoniae among Bangladeshi children under age 5 years with acute respiratory infections. 1682 46

This study describes the development and evaluation of a specific Legionella pneumophila Taqman duplex real-time PCR (qPCR) for fast and reliable quantification of this human pathogen in suspected man-made water systems. The qPCR assay was 100% specific for all L. pneumophila serogroups 1-15 with a sensitivity of 60 genome units/l and an amplification efficiency of 98%. Amplification inhibitors were detected via an exogenous internal positive control, which was amplified simultaneously with L. pneumophila DNA using its own primer and probe set. Mean recovery rates of the qPCR assay for tap water and cooling circuit water, spiked with a known number L. pneumophila bacteria, were 93.0% and 56.3%, respectively. Additionally, by using the Ultraclean Soil DNA isolation kit, we were able to remove amplification inhibitors ubiquitously present in cooling water. The practical value of our qPCR assay was evaluated through analysis of 30 water samples from showers, taps, eyewash stations, fire sprinklers and recirculation loops with qPCR and traditional culture. In conclusion, the described L. pneumophila Taqman duplex real-time assay proved to be specific, sensitive and reproducible. This makes it a promising method complementing the current time-consuming culture standard method.
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PMID:Development and evaluation of a Taqman duplex real-time PCR quantification method for reliable enumeration of Legionella pneumophila in water samples. 1691 18

Duopath Legionella is a new immunochromatographic assay for the identification of Legionella pneumophila and Legionella spp. As excellent specificity has been previously reported for this kit, we attempted an evaluation of its sensitivity using L. pneumophila serogroup 1 and Legionella anisa strains. Bacterial suspensions of L. pneumophila at concentrations of 1.2 x 10(8) cfu/ml and 1.2 x 10(7) cfu/ml were detected, but those below 1.2 x 10(6) cfu/ml were not recognized by the Duopath kit. After centrifugation and the sediment resuspension, a 2.8 x 10(7) cfu/ml concentration of bacterial suspension showed a positive result, but negative results were obtained below 2.8 x 10(6) cfu/ml. Also, bacterial suspension with concentrations of 3.2 x 10(9) cfu/ml and 1.4 x 10(9) cfu/ml after centrifugation of L.anisa were detected, but those below 3.2 x 10(8) cfu/ml and 1.4 x 10(8) cfu/ml after centrifugation were not recognized by the Duopath kit. Meanwhile, this kit was less sensitive to the L. pneumophila serogroup 1 suspension, and was more sensitive to the L. pneumophila serogroup 2 and L.anisa than the Binax NOW immunochromatographic kit. It was realized that the sensitivity of this kit is too low for determining the presence of Legionella in water samples. Although this kit may have excellent specificity, it has low sensitivity.
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PMID:Comparative evaluation of Duopath Legionella lateral flow assay against the conventional culture method using Legionella pneumophila and Legionella anisa strains. 1764 37

Duopath Legionella (Merck KGaA, Darmstadt, Germany) is a rapid and simple immunochromatographic assay kit for the identification of Legionella species. We evaluated the precision of the kit in identifying 100 strains of Legionella and 35 strains of non-Legionella bacteria isolated from cooling tower and bath water samples. Consequently, of all the Legionella strains tested, 99 strains were judged to be Legionella, and only one strain (Legionella busanensis) was judged to be non-Legionella. All of the 35 non-Legionella strains were judged to be non-Legionella. We therefore conclude that Duopath Legionella is a useful method for the rapid identification of Legionella.
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PMID:Evaluation of Duopath Legionella kit for the rapid identification of Legionella strains isolated from water samples. 1819 22


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