-
Lancet (London, England) Jan 2016Since first identified in early 1977, bacteria of the genus Legionella are recognised as a common cause of community-acquired pneumonia and a rare cause of... (Review)
Review
Since first identified in early 1977, bacteria of the genus Legionella are recognised as a common cause of community-acquired pneumonia and a rare cause of hospital-acquired pneumonia. Legionella bacteria multisystem manifestations mainly affect susceptible patients as a result of age, underlying debilitating conditions, or immunosuppression. Water is the major natural reservoir for Legionella, and the pathogen is found in many different natural and artificial aquatic environments such as cooling towers or water systems in buildings, including hospitals. The term given to the severe pneumonia and systemic infection caused by Legionella bacteria is Legionnaires' disease. Over time, the prevalence of legionellosis or Legionnaires' disease has risen, which might indicate a greater awareness and reporting of the disease. Advances in microbiology have led to a better understanding of the ecological niches and pathogenesis of the condition. Legionnaires' disease is not always suspected because of its non-specific symptoms, and the diagnostic tests routinely available do not offer the desired sensitivity. However, effective antibiotics are available. Disease notification systems provide the basis for initiating investigations and limiting the scale and recurrence of outbreaks. This report reviews our current understanding of this disease.
Topics: Anti-Bacterial Agents; Bacteriological Techniques; Culture Techniques; Disease Outbreaks; Disease Reservoirs; Humans; Incidence; Infectious Disease Incubation Period; Legionella; Legionnaires' Disease; Risk Factors; Water Supply
PubMed: 26231463
DOI: 10.1016/S0140-6736(15)60078-2 -
Trends in Microbiology Sep 2021
Review
Topics: Animals; Anti-Bacterial Agents; Humans; Legionella pneumophila; Legionnaires' Disease
PubMed: 33994277
DOI: 10.1016/j.tim.2021.04.005 -
Annual Review of Pathology Jan 2020species are environmental gram-negative bacteria able to cause a severe form of pneumonia in humans known as Legionnaires' disease. Since the identification of in... (Review)
Review
species are environmental gram-negative bacteria able to cause a severe form of pneumonia in humans known as Legionnaires' disease. Since the identification of in 1977, four decades of research on biology and Legionnaires' disease have brought important insights into the biology of the bacteria and the molecular mechanisms that these intracellular pathogens use to cause disease in humans. Nowadays, species constitute a remarkable model of bacterial adaptation, with a genus genome shaped by their close coevolution with amoebae and an ability to exploit many hosts and signaling pathways through the secretion of a myriad of effector proteins, many of which have a eukaryotic origin. This review aims to discuss current knowledge of infection mechanisms and future research directions to be taken that might answer the many remaining open questions. This research will without a doubt be a terrific scientific journey worth taking.
Topics: Adaptation, Physiological; Amoeba; Eukaryotic Cells; Host-Pathogen Interactions; Humans; Legionella; Legionella pneumophila; Legionnaires' Disease
PubMed: 31657966
DOI: 10.1146/annurev-pathmechdis-012419-032742 -
Infectious Disease Clinics of North... Mar 2017Severe legionella pneumonia poses a diagnostic challenge and requires early intervention. Legionnaire's disease can have several presenting signs, symptoms, and... (Review)
Review
Severe legionella pneumonia poses a diagnostic challenge and requires early intervention. Legionnaire's disease can have several presenting signs, symptoms, and laboratory abnormalities that suggest that Legionella pneumophila is the pathogen, but none of these are sufficient to distinguish L pneumophila pneumonia from other respiratory pathogens. L pneumophila is primarily an intracellular pathogen and needs treatment with antibiotics that efficiently enter the intracellular space.
Topics: Anti-Bacterial Agents; Community-Acquired Infections; Diagnosis, Differential; Humans; Legionella pneumophila; Legionnaires' Disease; Pneumonia
PubMed: 28159171
DOI: 10.1016/j.idc.2016.10.009 -
Revue Medicale Suisse Oct 2017Legionellosis refers to the two clinical syndromes caused by Legionella : Pontiac fever, a benign febrile illness and Legionnaires'disease (or pneumonia). Clinically and...
Legionellosis refers to the two clinical syndromes caused by Legionella : Pontiac fever, a benign febrile illness and Legionnaires'disease (or pneumonia). Clinically and radiologically, Legionnaires'disease presents itself as a « typical » pneumonia caused by Streptococcus pneumonia. Diagnosis is usually made by using urinary antigen testing. Culture and PCR are also helpful. Legionella is resistant to betalactam antibiotics, and is treated by quinolones or macrolides.
Topics: Anti-Bacterial Agents; Humans; Legionellosis; Legionnaires' Disease
PubMed: 29022658
DOI: No ID Found -
Current Environmental Health Reports Jun 2018The global importance of Legionnaires' disease (LD) and Pontiac fever (PF) has grown in recent years. While sporadic cases of LD and PF do not always provide contextual... (Review)
Review
PURPOSE OF REVIEW
The global importance of Legionnaires' disease (LD) and Pontiac fever (PF) has grown in recent years. While sporadic cases of LD and PF do not always provide contextual information for evaluating causes and drivers of Legionella risks, analysis of outbreaks provides an opportunity to assess these factors.
RECENT FINDINGS
A review was performed and provides a summary of LD and PF outbreaks between 2006 and 2017. Of the 136 outbreaks, 115 were LD outbreaks, 4 were PF outbreaks, and 17 were mixed outbreaks of LD and PF. Cooling towers were implicated or suspected in the a large portion of LD or PF outbreaks (30% total outbreaks, 50% confirmed outbreak-associated cases, and 60% outbreak-associated deaths) over this period of time, while building water systems and pools/spas were also important contributors. Potable water/building water system outbreaks seldom identify specific building water system or fixture deficiencies. The outbreak data summarized here provides information for prioritizing and targeting risk analysis and mitigation strategies.
Topics: Disease Outbreaks; Humans; Legionnaires' Disease; Water Microbiology; Water Supply
PubMed: 29744757
DOI: 10.1007/s40572-018-0201-4 -
Journal of Molecular Cell Biology Nov 2023Legionella pneumophila is a Gram-negative bacterium ubiquitously present in freshwater environments and causes a serious type of pneumonia called Legionnaires' disease.... (Review)
Review
Legionella pneumophila is a Gram-negative bacterium ubiquitously present in freshwater environments and causes a serious type of pneumonia called Legionnaires' disease. During infections, L. pneumophila releases over 300 effector proteins into host cells through an Icm/Dot type IV secretion system to manipulate the host defense system for survival within the host. Notably, certain effector proteins mediate posttranslational modifications (PTMs), serving as useful approaches exploited by L. pneumophila to modify host proteins. Some effectors catalyze the addition of host protein PTMs, while others mediate the removal of PTMs from host proteins. In this review, we summarize L. pneumophila effector-mediated PTMs of host proteins, including phosphorylation, ubiquitination, glycosylation, AMPylation, phosphocholination, methylation, and ADP-ribosylation, as well as dephosphorylation, deubiquitination, deAMPylation, deADP-ribosylation, dephosphocholination, and delipidation. We describe their molecular mechanisms and biological functions in the regulation of bacterial growth and Legionella-containing vacuole biosynthesis and in the disruption of host immune and defense machinery.
Topics: Humans; Legionella pneumophila; Legionnaires' Disease; Protein Processing, Post-Translational; Vacuoles; Ubiquitination
PubMed: 37156500
DOI: 10.1093/jmcb/mjad032 -
Respiratory Investigation Mar 2024
Topics: Humans; Legionella; Legionnaires' Disease; Legionella pneumophila
PubMed: 38301531
DOI: 10.1016/j.resinv.2024.01.008 -
Legionella feeleii: pneumonia or Pontiac fever? Bacterial virulence traits and host immune response.Medical Microbiology and Immunology Feb 2019Gram-negative bacterium Legionella is able to proliferate intracellularly in mammalian host cells and amoeba, which became known in 1976 since they caused a large... (Review)
Review
Gram-negative bacterium Legionella is able to proliferate intracellularly in mammalian host cells and amoeba, which became known in 1976 since they caused a large outbreak of pneumonia. It had been reported that different strains of Legionella pneumophila, Legionella micdadei, Legionella longbeachae, and Legionella feeleii caused human respiratory diseases, which were known as Pontiac fever or Legionnaires' disease. However, the differences of the virulence traits among the strains of the single species and the pathogenesis of the two diseases that were due to the bacterial virulence factors had not been well elucidated. L. feeleii is an important pathogenic organism in Legionellae, which attracted attention due to cause an outbreak of Pontiac fever in 1981 in Canada. In published researches, it has been found that L. feeleii serogroup 2 (ATCC 35849, LfLD) possess mono-polar flagellum, and L. feeleii serogroup 1 (ATCC 35072, WRLf) could secrete some exopolysaccharide (EPS) materials to the surrounding. Although the virulence of the L. feeleii strain was evidenced that could be promoted, the EPS might be dispensable for the bacteria that caused Pontiac fever. Based on the current knowledge, we focused on bacterial infection in human and murine host cells, intracellular growth, cytopathogenicity, stimulatory capacity of cytokines secretion, and pathogenic effects of the EPS of L. feeleii in this review.
Topics: Animals; Cell Line; Cytokines; Humans; Legionella; Legionnaires' Disease; Mice; Polysaccharides, Bacterial; Virulence; Virulence Factors
PubMed: 30386929
DOI: 10.1007/s00430-018-0571-0 -
Przeglad Epidemiologiczny 2023The 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...
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.
RESULTS
In Poland, both Legionnaires' disease (an acute infection that progresses to pneumonia) and Pontiac fever (a mild, flu-like sickness) are reported. In 2018-2021, a total of 255 cases of legionellosis were registered, including 236 cases of Legionnaires' disease and 19 cases of Pontiac fever. Each year, there was an increase in the number of notifications compared to the annual median number of cases from 2013-2017. The annual incidence rate in 2019 (0.23 per 100,000 population) was the highest since the start of legionellosis case registration in Poland. It declined again during the years of the COVID-19 pandemic. The notifications occurred throughout the country, but the highest notification rate was observed in the western belt of voivodeships. Pomorskie reported the highest incidence, accounting for more than 20% of all registered cases. The median incidence of Legionnaires' disease in men (0.23 per 100,000) was more than twice that of women (0.10), with the highest incidence (0.58) recorded in men 65 years of age or older. All indigenous cases of Legionnaires' disease were sporadic; all but three patients were hospitalized. State Sanitary Inspection reported 26 fatal cases of Legionnaires' disease (mortality = 11%). Twenty-four cases were linked to contaminated water systems in health-care settings, and 21 cases were likely associated with travel abroad.
SUMMARY AND CONCLUSIONS
Although the number of notifications has increased in recent years, Legionnaires' disease is still an infrequently diagnosed respiratory infection in Poland, and the reported incidence remains one of the lowest in the entire EU. The most affected demographic group is men aged 65 and older. Improving the early diagnosis of Legionnaires' disease in healthcare settings remains a priority.
Topics: Male; Humans; Female; Aged; Legionnaires' Disease; Poland; Pandemics; Disease Outbreaks; Registries; COVID-19; Legionellosis; Incidence; Communicable Diseases
PubMed: 37861069
DOI: 10.32394/pe.77.23