| Legionella clemsonensis | |
|---|---|
Scientific classification  | |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Gammaproteobacteria |
| Order: | Legionellales |
| Family: | Legionellaceae |
| Genus: | Legionella |
| Species: | L. clemsonensis |
| Binomial name | |
| Legionella clemsonensis Palmer et al. 2016 | |
Legionella clemsonensis was isolated in 2006, but was described in 2016 by Clemson University researchers. [1] It is a Gram-negative bacterium.
“Legionella” is named after the American Legion convention where the first outbreak occurred, killing 34 people and sickening 221 individuals in 1976. [2] It occurred in Philadelphia during the convention for the association of the U.S. veterans. The specific name clemsonensis” derives from Clemson University, where undergraduates DNA-sequenced this new strain. [3] Legionella has a correlation with another genus called Coxiella . Both cause lung infection that can eventually lead to pneumonia due to the intracellular bacteria in aerosols. [4]
Based on physical characteristics, phylogenetic analysis, and membrane fatty-acid composition, the organism was found to represent a unique lineage within the Legionella bacteria. The specific strain for Legionella clemsonensis is D5610. [5] It was named in honor of the research group of students from the Clemson’s Creative Inquiry. [1] Legionella clemsonensis was first isolated in 2006 from the bronchial wash of a patient diagnosed with pneumonia. [5] Bronchial washing is part of a bronchoscopy procedure. [5] After being isolated and stored, strain D5610 was acquired by the Centers for Disease Control and Prevention (CDC), [1] which sent 68 strains of Legionella, including strain D5610, for students to analyze at Clemson. [1] When isolated, it was shown to be very similar to bacterial genus Legionella . Researchers stated "it was identified as Legionella based on sequencing, cellular fatty-acid analysis, biochemical reactions, and biofilm characterization." [5] For a physical characterization of L.a clemsonensis, it was streaked for a single colony isolation using a charcoal yeast extract agar and required cysteine for primary isolation. [5] No growth was shown, which is typical of Legionella strains. A characteristic of L. clemsonensis is that it has a single, polar flagellum. [5] Researchers also used fatty-acid methyl-ester analyses to distinguish differences between the Legionella strains. [5] Cellular fatty-acid composition was analyzed using a Sherlock microbial Identification System. [6]
Legionella clemsonensis was determined as a special lineage within the genus Legionella based on its phylogenetic analysis and physical appearance. It is a Gram-negative bacterium that is rod-shaped with one polar flagellum to help it move around. The strain can grow between 26 and 45 °C, forming biofilms that are similar to L. pneumophila Philadelphia 1. [5] The strain D5610 of L. clemsonensis shows a distinctive temperature constraint compared to many of the Legionella species that do not grow under 26 °C and a restriction of temperatures above 45 °C . Most Legionella species have the ability to grow as high as 63 °C and very slowly at temperatures as low as 5 °C. [6] At both 37 and 26 °C, strain D5610 was found to grow more slowly than L. pneumophila Philadelphia 1, and it also formed a significant amount of pigment that was less produced. [6] These attributes suggest that this isolation is a standard Legionella species, for which the name Legionella clemsonensis was used. Legionella is considered to be pathogenic in humans and is one of the leading outbreaks found in constructed water systems. Because the biofilms are the source, countless outbreaks that originated from water systems and the ability of a species to form biofilms both can contribute to L. clemonensis’s pathogenicity. [7] The process of characterizing and sequencing the strain D5610 is still undergoing investigation. Because this strain is still being investigated, no specific metabolism has been shown for L. clemsonensis. Yet, Legionella’s usual metabolism is a facultative intracellular pathogen that increases in large numbers inside free-living amoebae, as well as macrophages and other protozoa. [8] In water systems, the pathogen lives in low metabolic state in the biofilms. A known strain of Legionella called in vitro L. pneumophila does not grow on standard media such as blood agar, because of a pH of 6.9 and certain amino acids such as cysteine being required. [7] Yet when these requirements are met, the growth in the aerobic conditions is still slow. Up to 5 days are needed for colonies to be produced. [8] The genomics have yet to be stated for this particular strain of Legionella, as well as the habitats.
Legionella clemsonensis is pathogenic; most Legionella species are commonly known to cause pneumonia. A feature that sets L. clemsonensis apart is that under ultraviolet light, it fluoresces green, [5] which differs from other Legionella strains because they usually fluoresce blue, red, or yellow. [5]
Legionella is a genus of pathogenic gram-negative bacteria that includes the species L. pneumophila, causing legionellosis including a pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever.
Atypical pneumonia, also known as walking pneumonia, is any type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of "typical" pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease, it is called primary atypical pneumonia (PAP).
Legionella pneumophila is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus Legionella. L. pneumophila is the primary human pathogenic bacterium in this group and is the causative agent of Legionnaires' disease, also known as legionellosis.
Coxiella burnetii is an obligate intracellular bacterial pathogen, and is the causative agent of Q fever. The genus Coxiella is morphologically similar to Rickettsia, but with a variety of genetic and physiological differences. C. burnetii is a small Gram-negative, coccobacillary bacterium that is highly resistant to environmental stresses such as high temperature, osmotic pressure, and ultraviolet light. These characteristics are attributed to a small cell variant form of the organism that is part of a biphasic developmental cycle, including a more metabolically and replicatively active large cell variant form. It can survive standard disinfectants, and is resistant to many other environmental changes like those presented in the phagolysosome.
The Legionellales are an order of Pseudomonadota. Like all Pseudomonadota, they are Gram-negative. They comprise two families, typified by Legionella and Coxiella, both of which include notable pathogens. For example, Q fever is caused by Coxiella burnetii and Legionella pneumophila causes Legionnaires' disease and Pontiac fever.
Staphylococcus epidermidis is a Gram-positive bacterium, and one of over 40 species belonging to the genus Staphylococcus. It is part of the normal human microbiota, typically the skin microbiota, and less commonly the mucosal microbiota and also found in marine sponges. It is a facultative anaerobic bacteria. Although S. epidermidis is not usually pathogenic, patients with compromised immune systems are at risk of developing infection. These infections are generally hospital-acquired. S. epidermidis is a particular concern for people with catheters or other surgical implants because it is known to form biofilms that grow on these devices. Being part of the normal skin microbiota, S. epidermidis is a frequent contaminant of specimens sent to the diagnostic laboratory.
Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host.
Xanthomonas campestris is a gram-negative, obligate aerobic bacterium that is a member of the Xanthomonas genus, which is a group of bacteria that are commonly known for their association with plant disease. The species is considered to be dominant amongst its genus, as it originally had over 140 identified pathovars and has been found to infect both monocotyledonous and dicotyledonous plants of economical value with various plant diseases. This includes "black rot" in cruciferous vegetables, bacterial wilt of turfgrass, bacterial blight, and leaf spot, for example.
Dictyostelium discoideum is a species of soil-dwelling amoeba belonging to the phylum Amoebozoa, infraphylum Mycetozoa. Commonly referred to as slime mold, D. discoideum is a eukaryote that transitions from a collection of unicellular amoebae into a multicellular slug and then into a fruiting body within its lifetime. Its unique asexual life cycle consists of four stages: vegetative, aggregation, migration, and culmination. The life cycle of D. discoideum is relatively short, which allows for timely viewing of all stages. The cells involved in the life cycle undergo movement, chemical signaling, and development, which are applicable to human cancer research. The simplicity of its life cycle makes D. discoideum a valuable model organism to study genetic, cellular, and biochemical processes in other organisms.
Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
Willaertia /ˈwɪləɹʃə/ is a genus of non-pathogenic, free-living, thermophilic amoebae in the family Vahlkampfiidae.
Legionella micdadei is a Gram-negative bacterium from the genus Legionella, which stains acid-fast. It stains weakly, but loses this trait upon being grown in culture. Tatlockia micdadei is an alternative term for L. micdadei, the Pittsburgh pneumonia agent and TATLOCK strain. It is named after Joseph E. McDade, who first isolated L. pneumophila.
The 1976 Legionnaires disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, United States was the first occasion in which a cluster of a particular type of pneumonia cases were determined to be caused by the Legionella pneumophila bacteria.
Variovorax paradoxus is a gram negative, beta proteobacterium from the genus Variovorax. Strains of V. paradoxus can be categorized into two groups, hydrogen oxidizers and heterotrophic strains, both of which are aerobic. The genus name Vario-vorax and species name para-doxus (contrary-opinion) reflects both the dichotomy of V. paradoxus metabolisms, but also its ability to utilize a wide array of organic compounds.
Legionella anisa is a Gram-negative bacterium, one of more than 40 species in the family Legionellaceae. After Legionella pneumophila, this species has been isolated most frequently from water samples. This species is also one of the several pathogenic forms of Legionella having been associated with rare clinical cases of illness including Pontiac fever and Legionnaires' disease.
Legionella cherrii is an aerobic, flagellated, Gram-negative bacterium from the genus Legionella. It was isolated from a heated water sample in Minnesota. L. cherrii is similar to another Legionella species, L. pneumophila, and is believed to cause major respiratory problems.
Legionella jordanis is a Gram-negative bacterium from the genus Legionella which was isolated from the Jordan River in Bloomington, Indiana and from the sewage in DeKalb County, Georgia. L. jordanis is a rare human pathogen and can cause respiratory tract infections.
Legionnaires' disease is a form of atypical pneumonia caused by any species of Legionella bacteria, quite often Legionella pneumophila. Signs and symptoms include cough, shortness of breath, high fever, muscle pains, and headaches. Nausea, vomiting, and diarrhea may also occur. This often begins 2–10 days after exposure.
Proteobiotics are natural metabolites which are produced by fermentation process of specific probiotic strains. These small oligopeptides were originally discovered in and isolated from culture media used to grow probiotic bacteria and may account for some of the health benefits of probiotics.
Amoebozoa of the free living genus Acanthamoeba and the social amoeba genus Dictyostelium are single celled eukaryotic organisms that feed on bacteria, fungi, and algae through phagocytosis, with digestion occurring in phagolysosomes. Amoebozoa are present in most terrestrial ecosystems including soil and freshwater. Amoebozoa contain a vast array of symbionts that range from transient to permanent infections, confer a range of effects from mutualistic to pathogenic, and can act as environmental reservoirs for animal pathogenic bacteria. As single celled phagocytic organisms, amoebas simulate the function and environment of immune cells like macrophages, and as such their interactions with bacteria and other microbes are of great importance in understanding functions of the human immune system, as well as understanding how microbiomes can originate in eukaryotic organisms.