Legionnaires disease

BACKGROUND: Legionella pneumonia, a severe form of pneumonia, is caused by Legionella bacteria. The epidemiology of Legionnaires' disease in Japan, including seasonal trends, risk factors for severe disease, and fatality rates, is unclear. This study examined the epidemiology of Legionella pneumonia in Japan. METHODS: This retrospective cohort study included data of adult patients hospitalized for Legionella pneumonia (identified using the ICD-10 code, A481) in the Japanese Diagnosis Procedure Combination inpatient database, from April 2011 to March 2021...

Case of a 44-year-old woman with past medical history of dermatomyositis who had been on Methrotexate therapy who became infected with Legionella pneumophila after staying at a home rental, known commercially as an Airbnb. The patient presented to the ER with complaints of general malaise and subsequently developed sepsis with respiratory failure requiring intubation. CT scan confirmed the diagnosis of pneumonia and through extensive research L. pneumophila was identified using a pneumonia panel that works by identifying nucleic acids of fastidious organisms that are difficult and take long to grow by culture...

Legionella is a common intracellular parasitic bacterium that infects humans via the respiratory tract, causing Legionnaires' disease, with fever and pneumonia as the main symptoms. The emergence of highly virulent and azithromycin-resistant Legionella pneumophila is a major challenge in clinical anti-infective therapy. The CRISPR-Cas acquired immune system provides immune defense against foreign nucleic acids and regulates strain biological functions. However, the distribution of the CRISPR-Cas system in Legionella and how it regulates gene expression in L...

PURPOSE/AIM OF THE STUDY: A case admitted with dysarthria and syncope and hyperintense lesion in the splenium of the corpus callosum, diagnosed as Legionnaires' disease by detecting Legionella antigen in the urine, and recovered only with antibiotic treatment is presented because it is rare in the literature. MATERIALS AND METHODS: When a 64-year-old female patient was admitted to the emergency department with complaints of sudden loss of consciousness and fainting at home, she had speech impairment, and her pulse oxygen saturation in room air was 88%...

Legionnaires disease is a serious infection acquired by inhalation of water droplets from human-made building water systems that contain Legionella bacteria. On July 11 and 12, 2022, Napa County Public Health (NCPH) in California received reports of three positive urinary antigen tests for Legionella pneumophila serogroup 1 in the town of Napa. By July 21, six Legionnaires disease cases had been confirmed among Napa County residents, compared with a baseline of one or two cases per year. NCPH requested assistance from the California Department of Public Health (CDPH) and CDC to aid in the investigations...

Due to a low index of suspicion coupled with specific growth conditions and non-specific clinical manifestations,  Legionella (L.) pneumophila  is a frequently misdiagnosed cause of pneumonia in immunocompromised patients, especially those with hematological malignancies. We present a case of severe acute respiratory distress syndrome (ARDS) secondary to Legionnaire's disease in a patient with newly diagnosed hairy cell leukemia (HCL) to highlight the importance of early recognition, diagnosis, and treatment of Legionnaire's disease to reduce morbidity and mortality...

Legionella pneumophila is an accidental human bacterial pathogen that infects and replicates within alveolar macrophages causing a severe atypical pneumonia known as Legionnaires' disease. As a prototypical vacuolar pathogen L. pneumophila establishes a unique endoplasmic reticulum (ER)-derived organelle within which bacterial replication takes place. Bacteria-derived proteins are deposited in the host cytosol and in the lumen of the pathogen-occupied vacuole via a type IVb (T4bSS) and a type II (T2SS) secretion system respectively...

BACKGROUND: Legionnaires' Disease (LD) rarely evolves into pulmonary abscesses. The current systematic review has been designed to explore therapeutical strategies in pulmonary cavitary LD. METHODS: A research strategy was developed and applied to the databases Embase, Pubmed, and Web of Science from the 1st of January 2000 to the 1st of November 2022. Original articles, case series, case reports, and guidelines written in English, French, German, Italian, and Dutch were considered...

Legionella pneumophila serogroup (SG) 1, the main cause of Legionnaires' disease, can be diagnosed with urinary antigen testing kits; however, lower respiratory tract specimen culture is necessary to identify L. pneumophila SG 2-15. We attempted to detect L. pneumophila SG-specific genes in a culture-negative sputum specimen from a patient with pneumonia suspected to have Legionnaires' disease. Two multiplex PCR methods targeting L. pneumophila were modified and amplicons considered to be SG13 specific were detected...

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A Legionella pneumophila bacterium is ubiquitous in water distribution systems, including dental unit waterlines (DUWLs). Legionellosis is atypical pneumonia, including Legionnaires' disease (LD) and the less acute form of Pontiac fever. Legionellosis occurs as a result of inhalation/aspiration of aerosolized Legionella -contaminated water by susceptible patients, health workers, and dentists. In this study, we undertook to determine the prevalence of Legionella in water and biofilm samples from Tap and DUWLs collected from five sites of dental clinics and faculties across the West Bank...

INTRODUCTION: Severe Legionnaires' disease (LD) can lead to multi-organ failure or death in 10%-30% of patients. Although hyper-inflammation and immunoparalysis are well described in sepsis and are associated with high disease severity, little is known about the immune response in LD. This study aimed to evaluate the immune status of patients with LD and its association with disease severity. METHODS: A total of 92 hospitalized LD patients were included; 19 plasmatic cytokines and pulmonary Legionella DNA load were measured in 84 patients on the day of inclusion (day 0, D0)...

BACKGROUND: Legionella pneumophila is a water-borne bacteria that can cause Legionnaires' disease. Monitoring of this organism in healthcare settings is paramount in keeping vulnerable populations protected. Legiolert® (IDEXX, USA) is a low-labour liquid-culture assay for the detection and enumeration of L. pneumophila (SG1-15) from water, requiring minimal operator training and providing confirmed results within 7 days. AIMS: Hospital water samples (n=100) were processed using both Legiolert® and ISO 11731:2017 plate-culture method (membrane-filtration and culture on selective agars) to analyse concordance between the procedures...

The study of virulence of Legionella pneumophila and its interactions with its hosts has been predominantly conducted in cellulo in the past decades. Although easy to implement and allowing the dissection of molecular pathways underlying host-pathogen interactions, these cellular models fail to provide conditions of the complex environments encountered by the bacteria during the infection of multicellular organisms. To improve our understanding of human infection, several animal models have been developed. This review provides an overview of the invertebrate and vertebrate models that have been established to study L...

In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. The donor's cause of death was freshwater drowning in a river, raising suspicion of potential donor-derived transmission, because Legionella bacteria naturally live in fresh water. Further investigation of patients receiving other organs from the same donor did not identify additional legionellosis cases...

Legionella pneumophila is a gram-negative bacteria found in natural and anthropogenic aquatic environments such as evaporative cooling towers, where it reproduces as an intracellular parasite of cohabiting protozoa. If L. pneumophila is aerosolized and inhaled by a susceptible person, bacteria may colonize their alveolar macrophages causing the opportunistic pneumonia Legionnaires' disease. L. pneumophila utilizes an elaborate regulatory network to control virulence processes such as the Dot/Icm Type IV secretion system and effector repertoire, responding to changing nutritional cues as their host becomes depleted...

Legionella pneumophila is an environmental bacterium, which replicates in amoeba but also in macrophages, and causes a life-threatening pneumonia called Legionnaires' disease. The opportunistic pathogen employs the α-hydroxyketone compound LAI-1 (Legionella autoinducer-1) for intra-species and inter-kingdom signaling. LAI-1 is produced by the autoinducer synthase LqsA, but it is not known, how LAI-1 is released by the pathogen. Here, we use a V. cholerae luminescence reporter strain and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect bacteria-produced and synthetic LAI-1...

OBJECTIVES: The aim of this study is to compare the epidemiological situation of legionellosis in Poland in 2018-2021 to prior years, taking into account the impact of the COVID-19 pandemic in 2020-2021. MATERIAL AND METHODS: The assessment is based on national surveillance data published in the annual bulletin "Infectious Diseases and Poisons in Poland" from 2013 to 2021, as well as data from Legionnaires' disease case reports collected and sent to the Department of Epidemiology of Infectious Diseases and Surveillance NIPH NIH - NRI by sanitary and epidemiological stations or submitted to EpiBase...

A widespread strategy employed by pathogens to establish infection is to inhibit host-cell protein synthesis. Legionella pneumophila, an intracellular bacterial pathogen and the causative organism of Legionnaires' disease, secretes a subset of protein effectors into host cells that inhibit translation elongation. Mechanistic insights into how the bacterium targets translation elongation remain poorly defined. We report here that the Legionella effector SidI functions in an unprecedented way as a transfer-RNA mimic that directly binds to and glycosylates the ribosome...

Infections of Legionnaires' disease in the United States caused by Legionella have increased ninefold between the years 2000-2018. Legionella harbored in biofilms or inside amoeba within premise plumbing can be more resistant to disinfectants, thus causing treatment challenges. Ultraviolet-light emitting diodes (UV-LEDs) are an emerging water disinfection technology with several advantages over conventional UV lamps. In this study, we evaluated the effects of UV-LEDs (255, 265, and 285 nm), a low-pressure (LP) mercury UV lamp (254 nm), and a bandpass filtered medium-pressure (MP) mercury UV lamp (220 nm) on properties and inactivation of three strains of L...