#bacter

• Abacterial — A medical term used to describe an environment, biological sample (urine, cerebrospinal fluid), or inflammatory process where no bacteria are present. An abacterial inflammation (such as abacterial cystitis or prostatitis) produces symptoms similar to an infection but is triggered by chemical, immune, traumatic factors, or viruses, with laboratory microbial cultures remaining negative.
• Abacteriemic — A medical term describing the state of an organism or circulating blood in which no viable bacteria are present. It is used clinically to confirm the absence of a systemic infection disseminated through the bloodstream or to describe the complete remission phase of a patient successfully treated for bacteremia, where repeated blood cultures turn negative.
• Abscessation / Abscess formation — The pathological process of abscess formation; the transformation of an acute inflammation or diffuse inflammatory infiltrate (such as cellulitis or phlegmon) into a well-circumscribed purulent collection, accompanied by liquefactive tissue necrosis.
• Abscess / Purulent pocket — A localized collection of pus, well-circumscribed by a newly formed pyogenic membrane, resulting from tissue destruction and liquefactive necrosis caused by an acute infection, most commonly bacterial (staphylococci, streptococci). Clinically characterized by classic signs of inflammation: pulsatile pain, swelling, local heat, redness, and fluctuance.
• abscess — (Medicine) A localized collection of pus within a tissue or organ, formed as a result of an acute inflammatory process, usually caused by a local bacterial infection.
• Acroposthitis — An acute or chronic inflammatory pathological process localized strictly at the level of the prepuce (the distal cutaneous sheath of the penis). This structural urological condition is most frequently caused by bacterial, fungal (such as candidiasis), or viral infections, poor local hygiene, chemical irritations, or mechanical traumas, clinically manifesting through marked edema, erythema (redness), intense pain, pruritus, and abnormal discharge, being closely correlated or frequently coexisting with balanitis (inflammation of the glans) to form the clinical picture known as balanoposthitis.
• Actinophage — A bacterial virus (bacteriophage) structurally specialized in infecting and destroying bacteria of the order Actinomycetales (actinomycetes). These viruses play an essential ecological and industrial role, being utilized in genetic research or bacterial infection control, but can also pose a structural threat in the biotechnology industry if they jeopardize bacterial cultures used for antibiotic production.
• Actinomycete — A gram-positive, predominantly aerobic bacterium belonging to the order Actinomycetales. Although evolutionarily and structurally prokaryotes (bacteria), these organisms exhibit a unique morphology, forming elongated branched filaments that mimic fungal mycelium. They are widespread in soil, playing a crucial ecological role in organic matter decomposition and possessing immense industrial value as the primary natural source for antibiotic production (such as streptomycin).
• Actinomycete — Common feminine form for the noun 'actinomicet'; a gram-positive, predominantly aerobic bacterium that exhibits a structural network of thin branched filaments mimicking the appearance of a fungal mycelium. Living primarily as a saprophyte in soil, an actinomycete is responsible for synthesizing many important bioactive compounds, being notable for producing geosmin (the substance giving the earthy smell after rain) and for manufacturing the majority of antibiotics used in modern medicine.
• Actinomycetales — Romanian name for the taxonomic order Actinomycetales, which groups gram-positive bacteria with a high guanine and cytosine content in their DNA, structurally characterized by their capacity to form branched filaments resembling fungal hyphae. These microorganisms play a major ecological role in decomposing complex organic matter in soil and are essential in biotechnology, serving as the primary natural source of secondary metabolites with antibiotic, antifungal, and immunosuppressive properties.
• Adelphotaxis — A biological or cytological phenomenon consisting of the mutual attraction, directed movement, and tendency for structural alignment or grouping of cells or unicellular organisms of the same species or with similar genetic characteristics. This cellular mechanism plays an important role in the early stages of bacterial colony organization or in tissue morphogenesis processes.
• Aerobacter — A genus of gram-negative, rod-shaped bacteria, motile or non-motile, aerobic or facultatively anaerobic, commonly found in soil, water, dairy products, and the digestive tract of humans and animals. These microorganisms possess the ability to ferment glucose and lactose, producing a large amount of gases and acids, and are sometimes involved in opportunistic urinary or respiratory tract infections in clinical settings.
• Aerobiology — An interdisciplinary branch of biology that deals with the study of living organisms and particles of biological origin (such as bacteria, fungi, pollen, spores, cysts, and viruses) passively transported through the air, as well as with the analysis of their movement, survival, and impact on the environment and human health.
• Aerobioscope — A laboratory apparatus used for collecting, filtering, and determining the number of microorganisms (bacteria, fungal spores) present in a specific volume of air. This device operates by bubbling air through a sterile liquid or by impacting particles onto a solid culture medium, being essential for air hygiene monitoring in hospitals, laboratories, and pharmaceutical industries.
• Aerobe — As a noun, it designates any organism (especially a microorganism, such as a bacterium or fungus) that requires free molecular oxygen to live and develop. As an adjective, it represents a less frequent linguistic variant of the term 'aerob', describing phenomena, environments, or beings adapted to the presence of air.
• Aerogenic — Producing, generating, or releasing gases or air during a chemical or biochemical reaction (for example, aerogenic bacteria that produce gas fermentation). Additionally, in epidemiology and medicine, it describes a mode of transmission or spread of pathogens through the air or in the form of aerosols.
• Aerogenesis — A biological, chemical, or pathological process of formation, production, and release of gases or air; in microbiology, it specifically refers to the capacity of certain anaerobic or facultative bacteria to generate gases (such as carbon dioxide or hydrogen) following carbohydrate metabolism and fermentation.
• Aerotaxis — A specific form of taxis or directed orientation and movement reaction of mobile microorganisms (bacteria, protozoa) triggered by the presence, concentration level, or partial pressure variation of oxygen or other gases in their living environment. This structural phenomenon guides aerobic bacteria toward oxygen-rich zones and anaerobic ones away from them.
• Aerotaxis — A specific form of taxis encountered in motile microorganisms, consisting of a reflex movement of orientation and displacement toward or away from a source of oxygen or other gases. This structural biological mechanism governs the attraction of aerobic bacteria to zones with optimal air concentration and the repulsion of strict anaerobes from oxygenated environments.
• Alexin — A historical term used in early immunology, introduced by Hans Buchner and popularized by Jules Bordet, to designate the complement system; a thermolabile protein substance present in normal blood serum capable of destroying bacteria and other foreign cells in cooperation with specific antibodies (sensitizers). In modern biochemistry, its action is studied as an integral part of the innate non-specific immune response of cell lysis.