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Microorganisms Nov 2022Atypical pathogens are intracellular bacteria causing community-acquired pneumonia (CAP) in a significant minority of patients. spp., and , , and are commonly... (Review)
Review
Atypical pathogens are intracellular bacteria causing community-acquired pneumonia (CAP) in a significant minority of patients. spp., and , , and are commonly included in this category. is present in 5-8% of CAP, being the second most frequent pathogen after . is found in 3-5% of inpatients. spp. and are present in less than 1% of patients. is relatively frequent in New Zealand and Australia and might also be present in other parts of the world. Uncertainty remains on the prevalence of atypical pathogens, due to limitations in diagnostic means and methodological issues in epidemiological studies. Despite differences between CAP caused by typical and atypical pathogens, the clinical presentation alone does not allow accurate discrimination. Hence, antibiotics active against atypical pathogens (macrolides, tetracyclines and fluoroquinolones) should be included in the empiric antibiotic treatment of all patients with severe CAP. For patients with milder disease, evidence is lacking and recommendations differ between guidelines. Use of clinical prediction rules to identify patients most likely to be infected with atypical pathogens, and strategies of narrowing the antibiotic spectrum according to initial microbiologic investigations, should be the focus of future investigations.
PubMed: 36557579
DOI: 10.3390/microorganisms10122326 -
Perspectives in Public Health Nov 2015Human disease caused by Legionella species is dominated by Legionella pneumophila, the main causative agent in cases of Legionnaires' disease. However, other species are... (Review)
Review
Human disease caused by Legionella species is dominated by Legionella pneumophila, the main causative agent in cases of Legionnaires' disease. However, other species are known to cause infection, for example, Legionella longbeachae causes an equivalent number of cases of disease as L. pneumophila in Australia and New Zealand. Infection with L. longbeachae is commonly associated with exposure to composts and potting soils, and cases of infection with this organism have been increasing in Europe over the past ten years. The increase in incidence may be linked to factors such as increased awareness of clinical presentation, or due to changing formulation of growing media, although it should be noted that the presence of Legionella species in growing media does not correlate with the number of cases currently seen. This is likely due to the variables associated with infection, for example, host factors such as smoking or underlying health conditions, or difference in growing media storage or climate, especially warm humid conditions, which may affect survival and growth of these organisms in the growing media environment. There are numerous unknowns in this area and collaboration between growing media manufacturers and researchers, as well as more awareness among diagnosing clinicians, laboratory staff and the general public is necessary to reduce risk. More research is needed before definitive conclusions can be drawn: L. pneumophila research currently dominates the field and it is likely that the overreliance on diagnostic techniques such as the urinary antigen test, which is specific for L. pneumophila Sg 1, is detrimental to the diagnosis of L. longbeachae infection.
Topics: Communicable Diseases, Emerging; Humans; Legionella longbeachae; Legionellosis; Soil Microbiology
PubMed: 26543151
DOI: 10.1177/1757913915611162 -
Emerging Infectious Diseases Apr 2011Reported cases of legionellosis attributable to Legionella longbeachae infection have increased worldwide. In Australia and New Zealand, L. longbeachae has been a known...
Reported cases of legionellosis attributable to Legionella longbeachae infection have increased worldwide. In Australia and New Zealand, L. longbeachae has been a known cause of legionellosis since the late 1980s. All cases for which a source was confirmed were associated with potting mixes and composts. Unlike the situation with other Legionella spp., L. longbeachae-contaminated water systems in the built environment that cause disease have not been reported. Spatially and temporally linked outbreaks of legionellosis associated with this organism also have not been reported. Sporadic cases of disease seem to be limited to persons who have had direct contact with potting soil or compost. Long-distance travel of the organism resulting in infection has not been reported. These factors indicate emergence of an agent of legionellosis that differs in etiology from other species and possibly in route of disease transmission.
Topics: Humans; Legionella longbeachae; Legionellosis; Prevalence; Soil Microbiology
PubMed: 21470444
DOI: 10.3201/eid1704.100446 -
Microorganisms Jan 2021Although known as causes of community-acquired pneumonia and Pontiac fever, the global burden of infection caused by species other than is under-recognised. Non-... (Review)
Review
Although known as causes of community-acquired pneumonia and Pontiac fever, the global burden of infection caused by species other than is under-recognised. Non- legionellae have a worldwide distribution, although common testing strategies for legionellosis favour detection of over other species, leading to an inherent diagnostic bias and under-detection of cases. When systematically tested for in Australia and New Zealand, was shown to be a leading cause of community-acquired pneumonia. Exposure to potting soils and compost is a particular risk for infection from , and may be better adapted to soil and composting plant material than other species. It is possible that the high rate of reported in Australia and New Zealand is related to the composition of commercial potting soils which, unlike European products, contain pine bark and sawdust. Genetic studies have demonstrated that the genomes are highly plastic, with areas of the chromosome showing high levels of recombination as well as horizontal gene transfer both within and between species via plasmids. This, combined with various secretion systems and extensive effector repertoires that enable the bacterium to hijack host cell functions and resources, is instrumental in shaping its pathogenesis, survival and growth. Prevention of legionellosis is hampered by surveillance systems that are compromised by ascertainment bias, which limits commitment to an effective public health response. Current prevention strategies in Australia and New Zealand are directed at individual gardeners who use potting soils and compost. This consists of advice to avoid aerosols generated by the use of potting soils and use masks and gloves, but there is little evidence that this is effective. There is a need to better understand the epidemiology of and other species in order to develop effective treatment and preventative strategies globally.
PubMed: 33572638
DOI: 10.3390/microorganisms9020291 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Oct 2021As a type of , can lead to very rare disease case in China with clinical characteristics, such as no typical early clinical symptoms, strong toxicity, high mortality,... (Review)
Review
As a type of , can lead to very rare disease case in China with clinical characteristics, such as no typical early clinical symptoms, strong toxicity, high mortality, and not easy to detect by conventional etiology. A case of severe pneumonia caused by infection was confirmed by bronchoalveolar lavage fluid pathogen metagenomics, and the patient's condition was improved after targeted anti-infection treatment. At present, our understanding in severe pneumonia is limited. The diagnosis and treatment process of the patient with severe pneumonia of is retrospectively analyzed and the relevant literature was reviewed to provide the experience for its future diagnosis and treatment.
Topics: Humans; Legionella; Legionella longbeachae; Legionellosis; Pneumonia; Retrospective Studies
PubMed: 34911849
DOI: 10.11817/j.issn.1672-7347.2021.200629 -
Emerging Infectious Diseases May 2017Legionella longbeachae is the primary cause of legionellosis in Australasia and Southeast Asia and an emerging pathogen in Europe and the United States; however, our...
Legionella longbeachae is the primary cause of legionellosis in Australasia and Southeast Asia and an emerging pathogen in Europe and the United States; however, our understanding of the population diversity of L. longbeachae from patient and environmental sources is limited. We analyzed the genomes of 64 L. longbeachae isolates, of which 29 were from a cluster of legionellosis cases linked to commercial growing media in Scotland in 2013 and 35 were non-outbreak-associated isolates from Scotland and other countries. We identified extensive genetic diversity across the L. longbeachae species, associated with intraspecies and interspecies gene flow, and a wide geographic distribution of closely related genotypes. Of note, we observed a highly diverse pool of L. longbeachae genotypes within compost samples that precluded the genetic establishment of an infection source. These data represent a view of the genomic diversity of L. longbeachae that will inform strategies for investigating future outbreaks.
Topics: Australia; Cluster Analysis; Computational Biology; Gene Flow; Genetic Variation; Genome, Bacterial; Genomics; High-Throughput Nucleotide Sequencing; Humans; Legionella longbeachae; Legionellosis; New Zealand; Phylogeny; Plasmids; RNA, Bacterial; RNA, Ribosomal, 16S; Recombination, Genetic; Scotland; Serogroup; United States
PubMed: 28418314
DOI: 10.3201/eid2305.161165 -
FEBS Letters Jul 2019Mucosal-associated invariant T (MAIT) cells are a subset of T cells that perform innate-like immunity functions upon recognition of small molecule vitamin B metabolites... (Review)
Review
Mucosal-associated invariant T (MAIT) cells are a subset of T cells that perform innate-like immunity functions upon recognition of small molecule vitamin B metabolites presented by the MHC, class I-related protein-1 (MR1). MAIT cells are profuse in humans, but especially abundant in blood, liver, lungs, and mucosal layers. The mucosa is a common site of carcinogenesis and MAIT cells have been found in both primary and metastatic tumors. MAIT cells target a host of microbes including Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica, Legionella longbeachae, Escherichia coli, and Candida albicans, and are highly activated in viral infections. Cytokines produced by MAIT cells are both anticancerous and antibacterial, but also have proinflammatory and possibly tumorigenic properties. In addition, it is believed that MAIT cells play a protective role in viral infections in an MR1-independent fashion. Based on our summary of recent advances concerning both MR1-mediated and MR1-independent MAIT cell immune responses, we weigh the strengths and weaknesses of these cells for vaccine development.
Topics: Animals; Histocompatibility Antigens Class I; Humans; Infections; Mucosal-Associated Invariant T Cells; Neoplasms; Vaccines
PubMed: 31206659
DOI: 10.1002/1873-3468.13488 -
The Netherlands Journal of Medicine Aug 2018We here report on two immunocompetent patients admitted to our hospital within 3 weeks' time, both suffering from pneumonia caused by Legionella longbeachae (L.... (Review)
Review
We here report on two immunocompetent patients admitted to our hospital within 3 weeks' time, both suffering from pneumonia caused by Legionella longbeachae (L. longbeachae). The pathogen was identified in broncho-alveolar lavage (BAL) liquid by Polymerase Chain Reaction (PCR), whereas sputum cultures remained negative. This organism is worldwide still relatively unknown and consequently underdiagnosed. However, with an increasing number of confirmed infections in Europe and more specifically in the Netherlands, early awareness and diagnostic measurements are indicated. As routine laboratory techniques like the urine antigen test do not detect L. longbeachae, we advocate early use of specific tests for non-pneumophila Legionella species such as PCR. Furthermore, we advocate the start of empirical antibiotic therapy (i.e. ciprofloxacin) and continuation in suspected cases.
Topics: Aged; Anti-Bacterial Agents; Blood Gas Analysis; DNA, Bacterial; Disease Progression; Humans; Immunocompetence; Incidence; Intensive Care Units; Legionella longbeachae; Legionellosis; Male; Netherlands; Polymerase Chain Reaction; Risk Assessment; Severity of Illness Index; Tomography, X-Ray Computed
PubMed: 30152395
DOI: No ID Found -
Frontiers in Cellular and Infection... 2023Extrapulmonary manifestations of infection with species, of which 24 may cause disease in humans, are very rare. Here, we describe a case of a 61-year-old woman with no... (Review)
Review
Extrapulmonary manifestations of infection with species, of which 24 may cause disease in humans, are very rare. Here, we describe a case of a 61-year-old woman with no history of immunosuppression presenting with pain and swelling of her index finger after a prick by rose thorns during gardening. Clinical examination showed fusiform swelling of the finger with mild redness, warmth, and fever. The blood sample revealed a normal white blood cell count and a slight increase in C-reactive protein. Intraoperative observation showed extensive infectious destruction of the tendon sheath, while the flexor tendons were spared. Conventional cultures were negative, while 16S rRNA PCR analysis identified that also could be isolated on buffered charcoal yeast extract media. The patient was treated with oral levofloxacin for 13 days, and the infection healed quickly. The present case report, with a review of the literature, indicates that species wound infections may be underdiagnosed due to the requirement for specific media and diagnostic methods. It emphasizes the need for heightened awareness of these infections during history taking and clinical examination of patients presenting with cutaneous infections.
Topics: Humans; Female; Middle Aged; Legionella longbeachae; Legionella; RNA, Ribosomal, 16S; Legionellosis; Wound Infection
PubMed: 37180442
DOI: 10.3389/fcimb.2023.1178130