Pseudomonadota is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The phylum Proteobacteria includes a wide variety of pathogenic genera, such as Escherichia, Salmonella, Vibrio, Yersinia, Legionella, and many others. Others are free-living (nonparasitic) and include many of the bacteria responsible for nitrogen fixation.
Campylobacter is a genus of Gram-negative bacteria. Campylobacter typically appear comma- or s-shaped, and are motile. Some Campylobacter species can infect humans, sometimes causing campylobacteriosis, a diarrhoeal disease in humans. Campylobacteriosis is usually self-limiting and antimicrobial treatment is often not required, except in severe cases or immunocompromised patients. The most known source for Campylobacter is poultry, but due to their diverse natural reservoir, Campylobacter spp. can also be transmitted via water. Other known sources of Campylobacter infections include food products, such as unpasteurised milk and contaminated fresh produce. Sometimes the source of infection can be direct contact with infected animals, which often carry Campylobacter asymptomatically. At least a dozen species of Campylobacter have been implicated in human disease, with C. jejuni (80–90%) and C. coli (5-10%) being the most common. C. jejuni is recognized as one of the main causes of bacterial foodborne disease in many developed countries. It is the number one cause of bacterial gastroentritis in Europe, with over 246,000 cases confirmed annually. C. jejuni infection can also cause bacteremia in immunocompromised people, while C. lari is a known cause of recurrent diarrhea in children. C. fetus can cause spontaneous abortions in cattle and sheep, and is an opportunistic pathogen in humans.
Pseudomonas is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture in vitro and availability of an increasing number of Pseudomonas strain genome sequences has made the genus an excellent focus for scientific research; the best studied species include P. aeruginosa in its role as an opportunistic human pathogen, the plant pathogen P. syringae, the soil bacterium P. putida, and the plant growth-promoting P. fluorescens, P. lini, P. migulae, and P. graminis.
Pseudomonas putida is a Gram-negative, rod-shaped, saprotrophic soil bacterium.
An opportunistic infection is an infection caused by pathogens that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune system, an altered microbiome, or breached integumentary barriers. Many of these pathogens do not necessarily cause disease in a healthy host that has a non-compromised immune system, and can, in some cases, act as commensals until the balance of the immune system is disrupted. Opportunistic infections can also be attributed to pathogens which cause mild illness in healthy individuals but lead to more serious illness when given the opportunity to take advantage of an immunocompromised host.
Pseudomonas aeruginosa is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, P. aeruginosa is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes.
Burkholderia cepacia complex (BCC), or simply Burkholderia cepacia, is a group of catalase-producing, lactose-nonfermenting, Gram-negative bacteria composed of at least 20 different species, including B. cepacia, B. multivorans, B. cenocepacia, B. vietnamiensis, B. stabilis, B. ambifaria, B. dolosa, B. anthina, B. pyrrocinia and B. ubonensis. B. cepacia is an opportunistic human pathogen that most often causes pneumonia in immunocompromised individuals with underlying lung disease. Patients with sickle-cell haemoglobinopathies are also at risk. The species complex also attacks young onion and tobacco plants, and displays a remarkable ability to digest oil. Burkholderia cepacia is also found in marine environments and some strains of Burkholderia cepacia can tolerate high salinity. S.I. Paul et al. (2021) isolated and biochemically characterized salt tolerant strains of Burkholderia cepacia from marine sponges of Saint Martin's Island of the Bay of Bengal, Bangladesh.
Stenotrophomonas maltophilia is an aerobic, nonfermentative, Gram-negative bacterium. It is an uncommon bacterium and human infection is difficult to treat. Initially classified as Bacterium bookeri, then renamed Pseudomonas maltophilia, S. maltophilia was also grouped in the genus Xanthomonas before eventually becoming the type species of the genus Stenotrophomonas in 1993.
Burkholderia gladioli is a species of aerobic gram-negative rod-shaped bacteria that causes disease in both humans and plants. It can also live in symbiosis with plants and fungi and is found in soil, water, the rhizosphere, and in many animals. It was formerly known as Pseudomonas marginata.
Pseudomonas oryzihabitans is a nonfermenting yellow-pigmented, gram-negative, rod-shaped bacterium that can cause sepsis, peritonitis, endophthalmitis, and bacteremia. It is an opportunistic pathogen of humans and warm-blooded animals that is commonly found in several environmental sources, from soil to rice paddies. They can be distinguished from other nonfermenters by their negative oxidase reaction and aerobic character. This organism can infect individuals that have major illnesses, including those undergoing surgery or with catheters in their body. Based on the 16S RNA analysis, these bacteria have been placed in the Pseudomonas putida group.
Pseudomonas stutzeri is a Gram-negative soil bacterium that is motile, has a single polar flagellum, and is classified as bacillus, or rod-shaped. While this bacterium was first isolated from human spinal fluid, it has since been found in many different environments due to its various characteristics and metabolic capabilities. P. stutzeri is an opportunistic pathogen in clinical settings, although infections are rare. Based on 16S rRNA analysis, this bacterium has been placed in the P. stutzeri group, to which it lends its name.
Ralstonia is a genus of bacteria, previously included in the genus Pseudomonas. It is named after the American bacteriologist Ericka Ralston. Ericka Ralston was born Ericka Barrett in 1944 in Saratoga, California, and died in 2015 in Sebastopol, California. While in graduate school at the University of California at Berkeley, she identified 20 strains of Pseudomonas which formed a phenotypical homologous group, and named them Pseudomonas pickettii, after M.J. Pickett in the Department of Bacteriology at the University of California at Los Angeles, from whom she had received the strains. Later, P. pickettii was transferred to the new genus Ralstonia, along with several other species. She continued her research into bacterial pathogenesis under the name of Ericka Barrett while a professor of microbiology at the University of California at Davis from 1977 until her retirement in 1996.
Ralstonia solanacearum is an aerobic non-spore-forming, Gram-negative, plant pathogenic bacterium. R. solanacearum is soil-borne and motile with a polar flagellar tuft. It colonises the xylem, causing bacterial wilt in a very wide range of potential host plants. It is known as Granville wilt when it occurs in tobacco. Bacterial wilts of tomato, pepper, eggplant, and Irish potato caused by R. solanacearum were among the first diseases that Erwin Frink Smith proved to be caused by a bacterial pathogen. Because of its devastating lethality, R. solanacearum is now one of the more intensively studied phytopathogenic bacteria, and bacterial wilt of tomato is a model system for investigating mechanisms of pathogenesis. Ralstonia was until recently classified as Pseudomonas, with similarity in most aspects, except that it does not produce fluorescent pigment like Pseudomonas. The genomes from different strains vary from 5.5 Mb up to 6 Mb, roughly being 3.5 Mb of a chromosome and 2 Mb of a megaplasmid. While the strain GMI1000 was one of the first phytopathogenic bacteria to have its genome completed, the strain UY031 was the first R. solanacearum to have its methylome reported. Within the R. solanacearum species complex, the four major monophyletic clusters of strains are termed phylotypes, that are geographically distinct: phylotypes I-IV are found in Asia, the Americas, Africa, and Oceania, respectively.
Ralstonia pickettii is a Gram-negative, rod-shaped, soil bacterium.
Ralstonia insidiosa is a Gram-negative, environmental bacterium. It has been shown to be a pathogenic in immunocompromised patients in hospital settings. This bacterium is closely related to Ralstonia pickettii.
Pseudomonas infection refers to a disease caused by one of the species of the genus Pseudomonas.
Cupriavidus metallidurans is a non-spore-forming, Gram-negative bacterium which is adapted to survive several forms of heavy metal stress.
Pneumonia can be classified in several ways, most commonly by where it was acquired, but may also by the area of lung affected or by the causative organism. There is also a combined clinical classification, which combines factors such as age, risk factors for certain microorganisms, the presence of underlying lung disease or systemic disease and whether the person has recently been hospitalized.
Vapotherm Inc. is a publicly held corporation based in Exeter, New Hampshire that was founded in 1999 as a medical device manufacturer after creating the first heated and humidified high flow therapy nasal cannula system.
Corynebacterium striatum is a bacterium that is a member of the Corynebacterium genus. It is classified as non-diphtheritic. The bacterium is a gram-positive prokaryote that assumes a 'club-like' morphology, more formally known as a corynebacteria structure. It is non-lipophilic and undergoes aerobic respiration and is also a facultative anaerobe it is catalase negative and oxidase positive glucose and sucrose fermenter.
