Microbiology Glossary
Browse our comprehensive collection of 777 microbiology terms and definitions.
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Sanitization
Sanitization is the process of reducing the number of microorganisms on a surface or in a product to levels considered safe by public health standards. It does...
Sapovirus
Sapovirus is a non-enveloped positive-sense RNA virus in the family Caliciviridae that causes acute gastroenteritis, particularly in young children. It was...
SARS-CoV
SARS CoV is the coronavirus responsible for the severe acute respiratory syndrome outbreak in 2002–2003. It is an enveloped, positive‑sense, single‑stranded...
SARS-CoV-2
SARS‑CoV‑2 is the novel coronavirus responsible for coronavirus disease 2019 COVID‑19, a respiratory illness first identified in Wuhan, China, in late 2019. It...
Secondary Infection
A secondary infection is a new infection that arises during or after treatment of a primary infection, often because normal host defences are weakened or the...
Selective Media
Selective media are culture media formulated to support the growth of a particular group of microorganisms while inhibiting other species. By incorporating...
SEM
SEM SEM stands for scanning electron microscope, an electron microscope that scans a specimen’s surface with a focused beam of electrons to produce...
Seoul Virus
Seoul virus is a member of the genus Orthohantavirus family Hantaviridae and is an Old World hantavirus causing a mild to moderate form of hemorrhagic fever...
Sepsis
Sepsis is a life‑threatening condition in which an infection triggers a dysregulated systemic response that leads to organ dysfunction. It represents the...
Septate
Septate describes fungal or algal filaments that are divided into distinct compartments by cross‑walls called septa. Each segment is separated by a partition...
Septicemia
Septicemia is a serious bloodstream infection in which bacteria or other pathogens circulate and multiply within the blood, leading to a systemic inflammatory...
Serology
Serology is the branch of immunology concerned with the study of serum and other body fluids to detect the presence of antibodies, antigens and other...
Serovar
A serovar, also called a serotype, is a distinct variant within a species of bacteria or virus that is defined by the antigenic properties of its surface...
Sheathed Bacteria
Sheathed bacteria are filamentous microorganisms that produce a tubular extracellular sheath encasing a chain of cells. This flexible sheath provides...
Siderophore
Siderophores are small, high‑affinity iron‑chelating molecules secreted by bacteria, fungi and some plants to scavenge and transport ferric iron in...
Sign
A sign is an objective indication of a disease or condition that can be observed or measured by a healthcare provider, as opposed to a symptom, which is...
Silent Mutation
A silent mutation is a change in a gene’s nucleotide sequence that does not alter the amino acid sequence of the encoded protein because of the redundancy in...
Simple Stain
A simple stain is a laboratory technique in which a single dye is applied to a specimen to enhance contrast and allow basic cell morphology to be observed with...
Sin Nombre Virus
Sin Nombre virus is a member of the genus Orthohantavirus family Hantaviridae and the principal etiological agent of hantavirus pulmonary syndrome HPS in North...
Slime Layer
A slime layer is a loose, unorganized layer of extracellular polymeric substances that surrounds some bacteria and can be easily removed from the cell surface....
SNS
The sympathetic nervous system SNS is a branch of the autonomic nervous system that mobilizes the body’s resources for “fight‑or‑flight” by increasing heart...
Southern Blot
A Southern blot is a molecular biology method for detecting specific DNA sequences in a complex sample by transferring DNA fragments from an electrophoresis...
Species
A species is the basic unit of biological classification, defined as a group of organisms that share common characteristics and, in sexually reproducing...
Spirochetes
Spirochetes are slender, spiral‑shaped bacteria with flexible helical cells and unique axial filaments that provide a corkscrew‑like motility. Explanation The...