Legionnaires disease

BACKGROUND: The number of reported cases of Legionnaires' disease, a severe pneumonia caused by the bacterium Legionella, is increasing in the United States. During 2000-2014, the rate of reported legionellosis cases increased from 0.42 to 1.62 per 100 000 persons; 4% of reported cases were outbreak-associated. Legionella is transmitted through aerosolization of contaminated water. A new industry standard for prevention of Legionella growth and transmission in water systems in buildings was published in 2015...

PURPOSE: Legionnaires' disease (LD) may occur sporadically or in the course of outbreaks, where the typical radiological manifestations of the disease may better be delineated. We took advantage of a rare community-based epidemic of LD (181 patients) that occurred in 2012 in Quebec City, Canada, to describe the radiographic features of LD and compare the its tomographic presentation with that of community-acquired pneumonia caused by common bacteria other than Legionella pneumophila. METHODS: From the 181 individuals affected in the outbreak, we obtained the chest radiographs of 159 individuals (mean 63 ± 15 years of age) for detailed analysis; 33 patients had a computed tomography (CT) scan performed during the course of their illness...

Infection due to Legionella pneumophila has been not studied in Colombia, although it is present. The observational, retrospective study in which the incidence of legionellosis in Colombia, 2009-2013, was estimated based on data extracted from the personal health records system (Registro Individual de Prestación de Servicios, RIPS) using the ICD-10 codes A48.1 (Legionnaires' disease) and A48.2 (Pontiac Fever). Using official population estimates of the National Administrative Department of Statistics (DANE), crude and adjusted incidence rates were estimated (cases / 100,000 pop)...

Legionella pneumophila contaminates man-made water systems and creates numerous exposure risks for Legionnaires' Disease. Because copper/silver ionization is commonly used to control L. pneumophila, its mechanisms of metal response and detoxification are of significant interest. Here we describe an L. pneumophila operon with significant similarity to the GIG operon of Cupriavidus metallidurans. The Legionella GIG operon is present in a subset of strains and has been acquired as part of the ICE-βox 65-kB integrative conjugative element...

PURPOSE: Rapid and effective diagnosis of Legionnaires' disease (LD) cases is extremely important so that timely and appropriate therapy can be provided, thereby lowering the morbidity and mortality rates and reducing the health and economic costs associated with this disease. METHODOLOGY: Diagnosis is established solely by microbiological tests. There are several methods available, each with different performance, sensitivity and specificity characteristics, and further understanding is required...

To investigate the immunoprotective effects of the recombinant type A flagellin (FLA), the flaA gene of Legionella pneumophila serogroup 1 strain Paris was cloned into pET28a(+). Recombinant FLA (rFLA) was overexpressed in E. coli BL21 (DE3) and purified by Ni2+ exchange chromatography. Female BALB/c aged 6-8 weeks were immunized with 20 μg of rFLA. Nonimmunized mice along with mice inoculated with a sublethal dose of live L. pneumophila intravenously were considered as negative and positive controls, respectively...

No abstract text is available yet for this article.

Legionella spp. are important waterborne pathogens. Molecular typing has become an important method for outbreaks investigations and source tracking of Legionnaires. In a survey program conducted by the Guangzhou Center for Disease Control and Prevention, multiple serotypes Legionella pneumophila (L. pneumophila) were isolated from waters in air-conditioning cooling towers in urban Guangzhou region, China between 2008 and 2011. Three genotyping methods, mip (macrophage infectivity potentiator) genotyping, SBT (sequence-based typing), and FAFLP (fluorescent amplified fragment length polymorphism analysis) were used to type these waterborne L...

Legionnaires disease is a severe form of pneumonia caused by the bacterium Legionella pneumophila. L. pneumophila pathogenicity relies on secretion of more than 300 effector proteins by a type IVb secretion system. Among these Legionella effectors, WipA has been primarily studied because of its dependence on a chaperone complex, IcmSW, for translocation through the secretion system, but its role in pathogenicity has remained unknown. In this study, we present the crystal structure of a large fragment of WipA, WipA435...

Early responses mounted by both tissue-resident and recruited innate immune cells are essential for host defense against bacterial pathogens. In particular, both neutrophils and Ly6Chi monocytes are rapidly recruited to sites of infection. While neutrophils and monocytes produce bactericidal molecules, such as reactive nitrogen and oxygen species, both cell types are also capable of synthesizing overlapping sets of cytokines important for host defense. Whether neutrophils and monocytes perform redundant or non-redundant functions in the generation of anti-microbial cytokine responses remains elusive...

INTRODUCTION AND OBJECTIVE: Several studies have reported therapy failures in patients with legionnaires'disease; however, antimicrobial resistance of clinical and environmental isolates of Legionella spp. has not yet been documented. Routine susceptibility testing of Legionella spp. is not recommended because of difficulties in determining standard minimal inhibitory concentration values. The purpose of this study was to analyze the antimicrobial susceptibility of Legionella pneumophila...

Legionella pneumophila is the main causative agent of Legionnaires' disease, which is a severe multi-system disease with pneumonia as the primary manifestation. We designed a recombinant Mip-PilE-FlaA dominant epitopes vaccine against Legionella pneumophila to prevent the disease and evaluated its immunogenicity and protective immunity. The protein structures of Mip, PilE and FlaA were analyzed using a computer, and the gene sequences of the dominant epitopes of the three proteins were selected to construct and optimize the vaccine...

The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires' disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires' disease outbreaks...

No abstract text is available yet for this article.

Legionnaires' disease is an acute fibrinopurulent pneumonia. During infection Legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. Here we provide a sequence and domain composition analysis of the L. pneumophila PilY1 protein, which has a high homology to PilY1 of Pseudomonas aeruginosa. PilY1 proteins of both pathogens contain a von Willebrand factor A (vWFa) and a C-terminal PilY domain. Using cellular fractionation, we assigned the L. pneumophila PilY1 as an outer membrane protein that is only expressed during the transmissive stationary growth phase...

Legionella oakridgensis is causing the Legionnaires' disease but is known to be less virulent than Legionella pneumophilaL. oakridgensis is one of the Legionella species that is non-flagellated. The genes of the flagellar regulon are absent; except the alternative sigma-28 factor (FliA) and its anti-sigma-28 factor (FlgM). Similar to L. oakridgensis, Legionella adelaidensis and Legionella londiniensis, located in the same phylogenetic clade, they have no flagellar regulon, although both are positive for fliA and flgM Herein, we investigated the role and function of both genes to better understand the role of FliA, the positive regulator of flagellin expression, in non-flagellated strains...

Background: Legionella pneumophila (L. pneumophila) is a gram-negative bacterium which causes ‎Legionnaires' disease as well as Pontiac fever. The Legionella infections in patients suffering from ‎neutropenia- as a common complication of cancer chemotherapy- can distribute rapidly. We ‎aimed to detect of L. pneumophila in haematological malignancy suffering patients with ‎neutropenic fever by targeting the (macrophage infectivity potentiator) mip gene. Subjects andMethods: Serum and ‎urine specimens were obtained from 80 patients and presence of mip gene of L...

The water-borne Gram-negative bacterium <i>Legionella pneumophila</i> (<i>Lp</i>) is the causative agent of Legionnaires' disease. <i>Lp</i> is typically transmitted to human from water systems, where it grows inside amoebae. Survival of <i>Lp</i> in water is central to its transmission to humans. A transcriptomic study previously identified many genes induced by <i>Lp</i> in water. One of such gene, <i>lpg2524</i>, encodes a putative LuxR family transcriptional regulator...

Legionella pneumophila, the causative agent of Legionnaires' diseases (LD) is usually transmitted to humans via inhalation of aerosols from contaminated natural and manmade water sources. These organisms may become fatal especially in immunocompromised patients and LD is the one of the important disease from a public health perspective. This survey investigated the frequency of Legionella spp. including L. pneumophila, in some cold and warm water systems in South-West of Iran by culture and PCR methods. Thirty four water samples were collected from diverse water supply systems...

BACKGROUND: An outbreak of Legionella pneumophila serogroup 1, with 403 cases was identified on the 7th November 2014 in Vila Franca de Xira, Portugal. Outbreak source was the wet cooling system of a local factory. Hospital Pulido Valente was one of the hospitals receiving patients with Legionnaires' disease (LD). METHODS: We describe the clinical findings and diagnostic methods used among the 43 confirmed or probable cases admitted to our department. RESULTS: 60...