#bacteria

• Amoxicillin — A semisynthetic antibiotic substance of the beta-lactam class, derived from penicillin, featuring a broad spectrum of antimicrobial activity against Gram-positive and Gram-negative bacteria. It acts by inhibiting bacterial cell wall synthesis during replication, being widely used in clinical practice to treat acute respiratory, urinary, cutaneous, or otorhinolaryngological infections.
• Ampicillin — A semi-synthetic antibiotic substance from the penicillin group, featuring a broad spectrum of activity, acid-stable but inactivated by beta-lactamases; it is widely utilized in medicine to treat various bacterial infections caused by susceptible microorganisms, acting by inhibiting bacterial cell wall synthesis during replication. It represents one of the most essential antimicrobial drugs included in fundamental therapeutic lists globally.
• Anaerobic — Said of organisms (bacteria, fungi) that can live, develop, or carry out their structural vital processes in the absence of free molecular oxygen; it also describes biochemical processes (fermentation, cellular respiration) taking place without the participation of oxygen. In sports physiology, it qualifies intense, short-duration physical efforts where energy is produced by breaking down carbohydrates without additional oxygen supply.
• Anaerobiont — A microorganism or lower organism that lives and structurally develops exclusively in an environment devoid of free molecular oxygen. This type of organism, primarily represented by denitrifying, methanogenic, or sulfate-reducing bacteria, obtains the energy required for its vital functions through alternative metabolic processes such as fermentation or anaerobic respiration.
• Antibacterial — A medication, chemical substance, or biological agent capable of destroying bacteria (bactericidal effect) or suppressing their growth and multiplication (bacteriostatic effect), spanning antibiotics, antiseptics, and sanitizers.
• Anti-cavity — Preventing, combating, or halting the onset and progression of dental caries; a chemical substance, active ingredient (such as fluoride or xylitol), or oral hygiene product (toothpaste, mouthwash) structurally formulated to protect dental enamel against bacterial demineralization and corrosive acids.
• Antipyogenic — Combating, preventing, destroying, or halting the formation of pus and the development of pyogenic bacteria, such as staphylococci or streptococci, responsible for suppurative tissue infections. This type of structural agent stimulates cellular cleansing, reduces inflammation, and blocks microbial multiplication in open infectious foci.
• Antitoxin — A specific antibody formed in the body of a human or animal as an immune response to the introduction of a bacterial, plant, or animal toxin, having the capacity to selectively neutralize its toxic effect. In medical practice, the term also designates the injectable pharmaceutical preparation obtained from the serum of immunized animals, used as an emergency treatment in serious infectious diseases such as diphtheria, tetanus, or botulism.
• Anthrax — An acute and highly severe infectious disease, common to humans and animals, caused by the spore-forming bacterium Bacillus anthracis. The condition is transmitted through direct contact with infected animals or contaminated products and can manifest in cutaneous (malignant pustule), pulmonary, or gastrointestinal forms, carrying a high mortality rate without early antibiotic treatment.
• Inoculation loop — A medical and laboratory instrument used in microbiology, consisting of a long handle and a thin metallic wire (made of platinum, nickel-chromium, or sterile plastic) ending in a small circular loop; it is used for collecting, transferring, and streaking bacterial culture inocula onto solid or liquid culture media.
• Apophylaxis — A local diminution of biological resistance or protective capacity of tissues against bacterial infections or external pathogens, often caused by inappropriate surgical intervention or the excessive or improper use of local antiseptics. The concept describes an iatrogenically induced vulnerability that destabilizes natural immune barriers and hinders the normal healing process.
• Arthropyosis — An acute or chronic infectious pathological process characterized by the accumulation of pus inside a joint cavity, associated with the rapid destruction of the synovial membrane and protective cartilage. This severe condition, clinically termed purulent septic arthritis, is caused by the penetration of pyogenic germs (bacteria) directly through trauma, non-sterile surgical interventions, or via the bloodstream from another infectious focus in the body.
• Asporogenous — Not producing spores, not reproducing through spores, or belonging to a species of microorganisms lacking the capacity to generate resistance endospores; an adjective used in bacteriology to classify vegetative bacteria (such as asporogenous forms) that are sensitive to heat and disinfectants, as opposed to sporogenous bacteria.
• Autogenous vaccine — An immunizing biological preparation (vaccine) harvested and manufactured specifically for a particular patient from a microbial strain (bacteria or viruses) isolated directly from their own chronic or recurrent infection site; this personalized serum targetedly stimulates the body's immune system to fight pathogens resistant to conventional antibiotic treatments.
• Autovaccination — The act of autovaccinating and its result; a therapeutic method based on the use of autogenous vaccines, consisting of the periodic and controlled inoculation of a microbial suspension harvested and prepared directly from the infectious site of the same patient, in order to stimulate the production of specific antibodies and eradicate a persistent chronic pathology.
• Auxoautotroph — An organism (especially a bacterial or fungal strain) that is capable of synthesizing by itself all the growth factors required for its metabolism (vitamins, amino acids), without needing organic supplements in the culture medium; an autotrophic organism in terms of tissue development factors.
• Azotobacter — A genus of aerobic, motile, oval or spherical bacteria that live freely in the soil and possess the remarkable capacity to fix molecular atmospheric nitrogen directly into organic compounds assimilable by plants, without establishing a symbiotic relationship with their roots; it is widely used in bio-agriculture as a biofertilizer to stimulate soil fertility.
• Azotobacterial — Pertaining to the bacterium genus Azotobacter, belonging to it, or produced by the metabolic activity of these microorganisms; often used to describe biological preparations, laboratory cultures, or non-symbiotic nitrogen-fixing processes in the soil.
• Azotobacterin — A bacterial preparation or biological fertilizer produced from pure cultures of Azotobacter chroococcum or other bacteria capable of fixing molecular nitrogen from the atmosphere. It is applied to seeds or directly into the soil to improve plant nitrogen nutrition, stimulating rhizosphere biological activity and increasing crop yields without synthetic chemical inputs.
• Bacillus — A rod-shaped, cylindrical bacterium with straight, rounded, or slightly concave ends, belonging in a broad sense to the class Bacilli, comprising numerous pathogenic or saprophytic microorganisms. These biological agents can be aerobic or anaerobic and are responsible for causing severe infectious diseases in human and animal organisms, such as tuberculosis, anthrax, tetanus, or leprosy, while also playing crucial roles in industrial fermentation processes.