Search results for "Legionella pneumophila"
showing 10 items of 33 documents
Recombination drives genome evolution in outbreak-related Legionella pneumophila isolates.
2014
Legionella pneumophila is a strictly environmental pathogen and the etiological agent of legionellosis. It is known that non-vertical processes have a major role in the short-term evolution of pathogens, but little is known about the relevance of these and other processes in environmental bacteria. We report the whole-genome sequencing of 69 L. pneumophila strains linked to recurrent outbreaks in a single location (Alcoy, Spain) over 11 years. We found some examples where the genome sequences of isolates of the same sequence type and outbreak did not cluster together and were more closely related to sequences from different outbreaks. Our analyses identify 16 recombination events responsibl…
Legionella pneumophila pangenome reveals strain-specific virulence factors
2010
Abstract Background Legionella pneumophila subsp. pneumophila is a gram-negative γ-Proteobacterium and the causative agent of Legionnaires' disease, a form of epidemic pneumonia. It has a water-related life cycle. In industrialized cities L. pneumophila is commonly encountered in refrigeration towers and water pipes. Infection is always via infected aerosols to humans. Although many efforts have been made to eradicate Legionella from buildings, it still contaminates the water systems. The town of Alcoy (Valencian Region, Spain) has had recurrent outbreaks since 1999. The strain "Alcoy 2300/99" is a particularly persistent and recurrent strain that was isolated during one of the most signifi…
Multiresistant waterborne pathogens isolated from water reservoirs and cooling systems
2008
Aims: To determine the incidence of multiple antibiotic-resistant strains of the emergent human pathogens Legionella pneumophila, Pseudomonas aeruginosa and mesophilic Aeromonas species among those isolated from water reservoirs and industrial cooling systems. Methods and Results: Water from four natural water reservoirs and four industrial cooling towers was sampled for 1 year period. The total heterotrophs, mesophilic Aeromonas, Pseudomonas spp. and Legionella spp. counts were performed as recommended by standard procedures, and the sensitivity of the isolates to 27 antibiotics was tested. A total of 117 Aeromonas, 60 P. aeruginosa and 15 L. pneumophila strains were isolated and identif…
Evolutionary Dissection of the Dot/Icm System Based on Comparative Genomics of 58 Legionella Species
2019
14 páginas, 2 figuras, 2 tablas
Legionellosis Outbreak Associated with Asphalt Paving Machine, Spain, 2009
2010
From 1999 through 2005 in Alcoi, Spain, incidence of legionellosis was continually high. Over the next 4 years, incidence was lower, but an increase in July 2009 led health authorities to declare an epidemic outbreak. A molecular epidemiology investigation showed that the allelic profiles for all Legionella pneumophila samples from the 2009 outbreak patients were the same, thus pointing to a common genetic origin for their infections, and that they were identical to that of the organism that had caused the previous outbreaks. Spatial-temporal and sequence-based typing analyses indicated a milling machine used in street asphalt repaving and its water tank as the most likely sources. As oppos…
Persistent Legionella Infection in a Patient after Bone Marrow Transplantation
2000
ABSTRACT We report on a patient who developed Legionella pneumonia after bone marrow transplantation. Despite appropriate antibiotic treatment, disease progressed. The patient developed a lung abscess from which Legionella and Prevotella were isolated. Cure was achieved by surgical resection. The resected material was sterile, but 16S ribosomal DNA analysis revealed Legionella DNA.
Acute respiratory failure onset in a patient with Guillain-Barré syndrome after Legionella-associated pneumonia: a case report.
2014
A 69-year-old white man was admitted because of a clinical history of persistent cough and fever. Chest x-rays showed bilateral lung infiltrates with air bronchograms, whereas the urine antigen test resulted positive for Legionella pneumophila. The next day, he was transferred to the intensive care unit and intubated because of severe renal and respiratory distress. Neurological examination revealed distal weakness and loss of deep tendon reflexes in lower extremities. Nerve conduction studies displayed severe demyelinating sensorimotor polyneuropathy, and plasmapheresis was therefore applied with mild improvement. Few weeks after, dysphagia occurred and electrophysiologic tests showed prog…
Mixed infection by Legionella pneumophila in outbreak patients.
2013
During the molecular epidemiological study of a legionellosis outbreak, we obtained sequence based typing (SBT) profiles from uncultured respiratory samples of 15 affected patients. We detected several distinct allelic profiles some of which were a mixture of alleles present in the more common profiles. Chromatograms from the sequences of one patient with mixed profile showed polymorphisms in several positions, which could result from the simultaneous presence of different Legionella variants in the sample. In order to test this possibility, we cloned PCR amplification products from six loci for two patients with a mixed profile and a patient with a pure profile. After obtaining around 20 s…
Direct sequencing of Legionella pneumophila from respiratory samples for sequence-based typing analysis.
2009
ABSTRACT We have developed a procedure to test the efficiency and reliability of sequencing of Legionella pneumophila genes directly from respiratory samples and have compared the results with those derived from cultured isolates. We tried to obtain the nucleotide sequences of six protein-coding loci included in the sequence-based typing scheme for Legionella pneumophila and three intergenic regions from 132 samples corresponding to 106 patients positive for urine antigen. A seminested PCR approach was used to amplify and sequence these nine loci directly from respiratory samples. Nucleotide sequences were directly obtained for 23 Legionella isolates and also for 66 respiratory secretions f…
Enzyme-linked immunoassay for detection of PCR-amplified DNA of legionellae in bronchoalveolar fluid.
1995
A nonradioactive method is described that detects 10 to 100 legionellae in 1 ml of bronchoalveolar lavage fluid. DNA is purified by a proteinase K-phenol protocol or with a commercial DNA preparation kit and amplified by PCR with amplimers specific for the 16S rRNA gene of Legionella pneumophila. The upstream primer is 5' biotinylated. The amplification product is immobilized on streptavidin-coated microtiter plates. Because of the high binding capacity, no removal of nonincorporated biotin from the PCR product is required. After alkaline denaturation, the single-stranded PCR product is hybridized with a 5' digoxigenin-labeled probing oligomer. The amplification product is then detected by …