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Emerging Infectious Diseases Jan 2016During June 2012-September 2014, we tested patients with severe respiratory illness for Legionella spp. infection and conducted a retrospective epidemiologic...
During June 2012-September 2014, we tested patients with severe respiratory illness for Legionella spp. infection and conducted a retrospective epidemiologic investigation. Of 1,805 patients tested, Legionella was detected in samples of 21 (1.2%); most were adults who had HIV or tuberculosis infections and were inappropriately treated for Legionella.
Topics: Child, Preschool; Female; Humans; Legionella; Legionella pneumophila; Legionellosis; Legionnaires' Disease; Male; Respiratory Tract Infections; Retrospective Studies; South Africa
PubMed: 26692504
DOI: 10.3201/eid2201.150972 -
Journal of Epidemiology and Community... Jun 2003
Topics: Environmental Monitoring; Epidemiological Monitoring; Humans; Legionnaires' Disease
PubMed: 12775779
DOI: 10.1136/jech.57.6.396 -
Texas Heart Institute Journal Aug 2015Legionnaires' disease is the designation for pneumonia caused by the Legionella species. Among the rare extrapulmonary manifestations, cardiac involvement is most... (Review)
Review
Legionnaires' disease is the designation for pneumonia caused by the Legionella species. Among the rare extrapulmonary manifestations, cardiac involvement is most prevalent, in the forms of myocarditis, pericarditis, postcardiotomy syndrome, and prosthetic valve endocarditis. Mechanical circulatory support has proved to be a safe and effective bridge to myocardial recovery in patients with acute fulminant myocarditis; however, to our knowledge, this support has not been used in infectious myocarditis specifically related to Legionellosis. We describe a case of Legionella myocarditis associated with acute left ventricular dysfunction and repolarization abnormalities in a 48-year-old man. The patient fully recovered after left ventricular unloading with use of a TandemHeart percutaneous ventricular assist device. In addition, we review the English-language medical literature on Legionella myocarditis and focus on cardiac outcomes.
Topics: Electrocardiography; Heart-Assist Devices; Humans; Legionella pneumophila; Legionnaires' Disease; Male; Middle Aged; Myocarditis; Prosthesis Design; Recovery of Function; Time Factors; Tomography, X-Ray Computed; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 26413019
DOI: 10.14503/THIJ-14-4131 -
Biomolecules Jan 2022is a Gram-negative, facultative intracellular pathogen that causes severe pneumonia known as Legionnaires' disease. The bacterium causes disease when contaminated water...
is a Gram-negative, facultative intracellular pathogen that causes severe pneumonia known as Legionnaires' disease. The bacterium causes disease when contaminated water is aerosolized and subsequently inhaled by individuals, which allows the bacteria to gain access to the lungs, where they infect alveolar macrophages. is ubiquitous in the environment, where it survives by growing in biofilms, intracellularly within protozoa, and planktonically. Biofilms are a major concern for public health because they provide a protective niche that allows for the continuous leaching of bacteria into the water supply. In addition, biofilms enhance the survival of the bacteria by increasing resistance to temperature fluctuations and antimicrobial agents. Currently, there is little known about biofilm formation and regulation by . Here, we present evidence of a specific gene, , which appears to be involved in the regulation of motility, biofilm formation, cellular replication, and virulence of . A strain lacking has an enhanced biofilm formation phenotype, forming biofilms that are both faster and thicker than wild type. Additionally, the knockout strain has significantly reduced motility, enhanced uptake into amoebae, and altered growth kinetics on solid media. Our data suggest a potential role for in signaling pathways that govern changes in growth rate and motility in response to environmental conditions.
Topics: Amoeba; Biofilms; Humans; Legionella pneumophila; Legionnaires' Disease; Virulence
PubMed: 35204726
DOI: 10.3390/biom12020225 -
Microbiology Spectrum Aug 2022Legionella pneumophila is the causative agent of a severe type of pneumonia (lung infection) called Legionnaires' disease. It is emerging as an antibiotic-resistant...
Legionella pneumophila is the causative agent of a severe type of pneumonia (lung infection) called Legionnaires' disease. It is emerging as an antibiotic-resistant strain day by day. Hence, identifying novel drug targets and vaccine candidates is essential to fight against this pathogen. Here, attempts were taken through a subtractive genomics approach on the complete proteome of L. pneumophila to address the challenges of multidrug resistance. A total of 2,930 proteins from L. pneumophila proteome were investigated through diverse subtractive proteomics approaches, e.g., identification of human nonhomologous and pathogen-specific essential proteins, druggability and "anti-target" analysis, subcellular localization prediction, human microbiome nonhomology screening, and protein-protein interaction studies to find out effective drug and vaccine targets. Only three fulfilled these criteria and were proposed as novel drug targets against L. pneumophila. Furthermore, outer membrane protein TolB was identified as a potential vaccine target with a better antigenicity score. Antigenicity and transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis, and a molecular docking approach were adopted to generate the most potent epitopes. The final vaccine was constructed by the combination of highly immunogenic epitopes, along with suitable adjuvant and linkers. The designed vaccine construct showed higher binding interaction with different major histocompatibility complex (MHC) molecules and human immune TLR-2 receptors with minimum deformability at the molecular level. The present study aids the development of novel therapeutics and vaccine candidates for efficient treatment and prevention of L. pneumophila infections. However, further wet-lab-based phenotypic and genomic investigations and trials are highly recommended to validate our prediction experimentally. Legionella pneumophila is a human pathogen distributed worldwide, causing Legionnaires' disease (LD), a severe form of pneumonia and respiratory tract infection. L. pneumophila is emerging as an antibiotic-resistant strain, and controlling LD is now difficult. Hence, developing novel drugs and vaccines against L. pneumophila is a major research priority. Here, the complete proteome of L. pneumophila was considered for subtractive genomics approaches to address the challenge of antimicrobial resistance. Our subtractive proteomics approach identified three potential drug targets that are promising for future application. Furthermore, a possible vaccine candidate, "outer membrane protein TolB," was proposed using reverse vaccinology analysis. The constructed vaccine candidate showed higher binding interaction with MHC molecules and human immune TLR-2 receptors at the molecular level. Overall, the present study aids in developing novel therapeutics and vaccine candidates for efficient treatment of the infections caused by L. pneumophila.
Topics: Anti-Bacterial Agents; Epitopes; Genomics; Humans; Legionella pneumophila; Legionnaires' Disease; Molecular Docking Simulation; Proteome; Toll-Like Receptor 2; Vaccinology
PubMed: 35863001
DOI: 10.1128/spectrum.00373-22 -
Scientific Reports Apr 2016Legionella pneumophila, the causative agent of Legionnaires' disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L....
Legionella pneumophila, the causative agent of Legionnaires' disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment.
Topics: Cell Line; Disease Reservoirs; Gene Expression Regulation, Bacterial; Genes, Bacterial; Host-Pathogen Interactions; Humans; Legionella pneumophila; Legionnaires' Disease; Macrophages; Mutation; Paramecium; Symbiosis
PubMed: 27079173
DOI: 10.1038/srep24322 -
Euro Surveillance : Bulletin Europeen... Feb 2010
Topics: Gardening; Legionella; Legionellosis; Legionnaires' Disease; Seasons; Soil Microbiology
PubMed: 20197025
DOI: 10.2807/ese.15.08.19497-en -
Infection Oct 2023Switzerland has one of the highest annual Legionnaires' disease (LD) notification rates in Europe (7.8 cases/100,000 population in 2021). The main sources of infection...
Switzerland has one of the highest annual Legionnaires' disease (LD) notification rates in Europe (7.8 cases/100,000 population in 2021). The main sources of infection and the cause for this high rate remain largely unknown. This hampers the implementation of targeted Legionella spp. control efforts. The SwissLEGIO national case-control and molecular source attribution study investigates risk factors and infection sources for community-acquired LD in Switzerland. Over the duration of one year, the study is recruiting 205 newly diagnosed LD patients through a network of 20 university and cantonal hospitals. Healthy controls matched for age, sex, and residence at district level are recruited from the general population. Risk factors for LD are assessed in questionnaire-based interviews. Clinical and environmental Legionella spp. isolates are compared using whole genome sequencing (WGS). Direct comparison of sero- and sequence types (ST), core genome multilocus sequencing types (cgMLST), and single nucleotide polymorphisms (SNPs) between clinical and environmental isolates are used to investigate the infection sources and the prevalence and virulence of different Legionella spp. strains detected across Switzerland. The SwissLEGIO study innovates in combining case-control and molecular typing approaches for source attribution on a national level outside an outbreak setting. The study provides a unique platform for national Legionellosis and Legionella research and is conducted in an inter- and transdisciplinary, co-production approach involving various national governmental and national research stakeholders.
Topics: Humans; Legionnaires' Disease; Legionella pneumophila; Switzerland; Prospective Studies; Disease Outbreaks; Case-Control Studies
PubMed: 36905400
DOI: 10.1007/s15010-023-02014-x -
BMC Pulmonary Medicine Dec 2017Because of a limited number of reports, we aimed to investigate the clinical characteristics of patients with Legionella pneumonia due to non-Legionella pneumophila...
BACKGROUND
Because of a limited number of reports, we aimed to investigate the clinical characteristics of patients with Legionella pneumonia due to non-Legionella pneumophila serogroup 1 and the diagnostic usefulness of the six-point scoring system for such patients compared with patients with pneumonia caused by L. pneumophila serogroup 1.
METHODS
We retrospectively analysed patients diagnosed with Legionella pneumonia due to non-L. pneumophila serogroup 1 between March 2001 and June 2016. We examined the clinical characteristics, including symptoms, laboratory findings, radiologic findings, pneumonia severity, initial treatment and prognosis. We also calculated scores using the six-point scoring system in these patients. Furthermore, we compared the clinical characteristics and six-point scores between non-L. pneumophila serogroup 1 patients and L. pneumophila serogroup 1 patients among hospitalized community-acquired pneumonia patients enrolled prospectively between October 2010 and July 2016.
RESULTS
Eleven patients had pneumonia due to non-L. pneumophila serogroup 1; their median age was 66 years and 8 patients (72.7%) were male. The most common pathogen was L. pneumophila serogroup 3 (6/11), followed by L. pneumophila serogroup 9 (3/11), L. pneumophila serogroup 6 (1/11) and L. longbeachae (1/11). Non-specific symptoms, such as fever and cough, were common. Six patients (54.5%) had liver enzyme elevation, but no patient developed hyponatraemia at <130 mEq/L. Nine patients (81.8%) showed lobar pneumonia and 7 patients (63.6%) manifested with consolidation and ground-glass opacity. Patients with mild to moderate severity comprised 10 (90.9%) by CURB-65 and 5 (45.5%) by the Pneumonia Severity Index. Of all patients, 4 were admitted to the intensive care unit and 3 died despite appropriate empiric therapy. The clinical characteristics were not significantly different between non-L. pneumophila serogroup 1 patients and L. pneumophila serogroup 1 patients (n = 23). At a cut-off value of ≥ 2 points, the sensitivity of the six-point scoring system was 54.5% (6/11) for non-L. pneumophila serogroup 1 patients and 95.7% (22/23) for L. pneumophila serogroup 1 patients.
CONCLUSIONS
Cases of non-L. pneumophila serogroup 1 pneumonia varied in severity from mild to severe and the clinical characteristics were often non-specific. The six-point scoring system was not useful in predicting such Legionella pneumonia cases.
Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Community-Acquired Infections; Female; Humans; Legionella pneumophila; Legionnaires' Disease; Male; Middle Aged; Retrospective Studies; Serogroup; Severity of Illness Index
PubMed: 29246145
DOI: 10.1186/s12890-017-0559-3 -
Journal of Microbiology, Immunology,... Jun 2019Legionella pneumophila had been recognized as an important pathogen for community-acquired pneumonia. We aimed to investigate clinical features and outcomes of patients...
BACKGROUND/PURPOSE
Legionella pneumophila had been recognized as an important pathogen for community-acquired pneumonia. We aimed to investigate clinical features and outcomes of patients with Legionnaires' disease at a tertiary medical center in northern Taiwan.
METHODS
From June 2012 to February 2017, a retrospective review of adult community-acquired. Legionnaires' disease at a medical center was conducted. All Legionella infections were confirmed by positive urinary Legionella antigen assay, sera indirect immunofluorescence assay, or sputum culture for Legionella. Literature review of Legionnaires' disease from Medline and PubMED websites was performed.
RESULTS
A total of 32 cases of Legionnaires' disease were identified. Their mean age was 64.3 years, with male predominance (27 cases, 84.3%). The underlying diseases were varied and most were attributed to chronic disorders, such as diabetes mellitus (31%) and cigarette smoking (40.6%). The most common symptoms were cough (68%) and fever (59.3%). More than half of patients (18, 56.2%) with Legionnaires' disease could initially present with extrapulmonary manifestations. Sixteen (50%) patients had delay in initiation of appropriate antibiotic therapy. Patients without adequately initiation of appropriate antibiotic therapy had higher proportion (11 of 16, 68.7%) of intensive care unit admission than patients with adequate initiation (5 of 16, 31.2%). Our results inferred that a delay in treatment might result in worsening of disease severity and the need for more intensive management. Overall mortality rate was 21.8%. Development of vasopressor requirement is an independent risk factor associated with mortality.
CONCLUSION
Legionnaires' disease in Taiwan frequently present with extrapulmonary manifestations. Patients with hemodynamic instability that need vasopressor therapy associated with mortality.
Topics: Anti-Bacterial Agents; Community-Acquired Infections; Female; Hospital Mortality; Hospitalization; Humans; Legionella pneumophila; Legionnaires' Disease; Male; Middle Aged; Retrospective Studies; Risk Factors; Taiwan; Tertiary Care Centers; Time-to-Treatment
PubMed: 28964650
DOI: 10.1016/j.jmii.2017.08.018