Pseudomonadota is a major phylum of Gram-negative bacteria. Currently, they are considered the predominant phylum within the realm of bacteria. They are naturally found as pathogenic and free-living (non-parasitic) genera. The phylum comprises six classes Acidithiobacilia, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Hydrogenophilia, and Zetaproteobacteria. The Pseudomonadota are widely diverse, with differences in morphology, metabolic processes, relevance to humans, and ecological influence.
The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the gastrointestinal tract, skin, mammary glands, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, and the biliary tract. Types of human microbiota include bacteria, archaea, fungi, protists, and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition. In the context of genomics, the term human microbiome is sometimes used to refer to the collective genomes of resident microorganisms; however, the term human metagenome has the same meaning.
Fusobacterium is a genus of obligate anaerobic, Gram-negative, non-sporeforming bacteria belonging to Gracilicutes. Individual cells are slender, rod-shaped bacilli with pointed ends. Fusobacterium was discovered in 1900 by Courmont and Cade and is common in the flora of humans.
Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic member of the genus Streptococcus. They are usually found in pairs (diplococci) and do not form spores and are non motile. As a significant human pathogenic bacterium S. pneumoniae was recognized as a major cause of pneumonia in the late 19th century, and is the subject of many humoral immunity studies.
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.
Xylella fastidiosa is an aerobic, Gram-negative bacterium of the genus Xylella. It is a plant pathogen, that grows in the water transport tissues of plants and is transmitted exclusively by xylem sap-feeding insects such as sharpshooters and spittlebugs. Many plant diseases are due to infections of X. fastidiosa, including bacterial leaf scorch, oleander leaf scorch, coffee leaf scorch (CLS), alfalfa dwarf, phony peach disease, and the economically important Pierce's disease of grapes (PD), olive quick decline syndrome (OQDS), and citrus variegated chlorosis (CVC). While the largest outbreaks of X. fastidiosa–related diseases have occurred in the Americas and Europe, this pathogen has also been found in Taiwan, Israel, and a few other countries worldwide.
Brenneria is a genus of Pectobacteriaceae, containing mostly pathogens of woody plants. This genus is named after the microbiologist Don J. Brenner.
Brenneria salicis is a Gram-negative bacterium that is pathogenic on plants.
Avian malaria is a parasitic disease of birds, caused by parasite species belonging to the genera Plasmodium and Hemoproteus. The disease is transmitted by a dipteran vector including mosquitoes in the case of Plasmodium parasites and biting midges for Hemoproteus. The range of symptoms and effects of the parasite on its bird hosts is very wide, from asymptomatic cases to drastic population declines due to the disease, as is the case of the Hawaiian honeycreepers. The diversity of parasites is large, as it is estimated that there are approximately as many parasites as there are species of hosts. As research on human malaria parasites became difficult, Dr. Ross studied avian malaria parasites. Co-speciation and host switching events have contributed to the broad range of hosts that these parasites can infect, causing avian malaria to be a widespread global disease, found everywhere except Antarctica.
Microbiota are the range of microorganisms that may be commensal, mutualistic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found to be crucial for immunologic, hormonal, and metabolic homeostasis of their host.
Tannerella forsythia is an anaerobic, Gram-negative bacterial species of the Bacteroidota phylum. It has been implicated in periodontal diseases and is a member of the red complex of periodontal pathogens. T. forsythia was previously named Bacteroides forsythus and Tannerella forsythensis.
Phytophthora kernoviae is a plant pathogen that mainly infects European beech and Rhododendron ponticum. It was first identified in 2003 in Cornwall, UK when scientists were surveying for the presence of Phytophthora ramorum. This made it the third new Phytophthora species to be found in the UK in a decade. It was named Phytophthora kernoviae after the ancient name for Cornwall, Kernow. It causes large stem lesions on beech and necrosis of stems and leaves of Rhododendron ponticum. It is self-fertile. It has also been isolated from Quercus robur and Liriodendron tulipifera. The original paper describing the species, stated it can infect Magnolia and Camellia species, Pieris formosa, Gevuina avellana, Michelia doltsopa and Quercus ilex. Since then many other plants have been identified as natural hosts of the pathogen. Molecular analysis has revealed that an infection on Pinus radiata, recorded in New Zealand in 1950, was caused by P. kernoviae. The pathogen was also noted on Drimys winteri, Gevuina avellana, Ilex aquifolium, Quercus ilex, Vaccinium myrtillus, Hedera helix, Podocarpus salignas.
In biology, a pathogen, in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.
The root microbiome is the dynamic community of microorganisms associated with plant roots. Because they are rich in a variety of carbon compounds, plant roots provide unique environments for a diverse assemblage of soil microorganisms, including bacteria, fungi, and archaea. The microbial communities inside the root and in the rhizosphere are distinct from each other, and from the microbial communities of bulk soil, although there is some overlap in species composition.
A microbiome is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps et al. as "a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity". In 2020, an international panel of experts published the outcome of their discussions on the definition of the microbiome. They proposed a definition of the microbiome based on a revival of the "compact, clear, and comprehensive description of the term" as originally provided by Whipps et al., but supplemented with two explanatory paragraphs. The first explanatory paragraph pronounces the dynamic character of the microbiome, and the second explanatory paragraph clearly separates the term microbiota from the term microbiome.
Agrilus biguttatus is a species of beetle in the family Buprestidae, the jewel beetles. Common names include oak splendour beetle, oak buprestid beetle, and two-spotted oak borer. This beetle is known as a pest that causes damage to oak trees and is a major factor in oak decline.
Microbiomes of the built environment is a field of inquiry into the communities of microorganisms that live in human constructed environments like houses, cars and water pipes. It is also sometimes referred to as microbiology of the built environment.
Since the colonization of land by ancestral plant lineages 450 million years ago, plants and their associated microbes have been interacting with each other, forming an assemblage of species that is often referred to as a holobiont. Selective pressure acting on holobiont components has likely shaped plant-associated microbial communities and selected for host-adapted microorganisms that impact plant fitness. However, the high microbial densities detected on plant tissues, together with the fast generation time of microbes and their more ancient origin compared to their host, suggest that microbe-microbe interactions are also important selective forces sculpting complex microbial assemblages in the phyllosphere, rhizosphere, and plant endosphere compartments.
Amy Proal is an American microbiologist who studies the effects of bacterial, fungal, and viral pathogens on human health at the molecular level. She is one of the founders of PolyBio Research Foundation, a company investigating the basis of chronic infection-associated illnesses, and currently serves on the company's board of directors. She has recently been noted for her work investigating the causes of long covid.
