Microbiology Glossary

Persistent Infection

A persistent infection is a prolonged association between a pathogen and its host in which the pathogen is not eliminated and remains within tissues for months...

Persistent Infection

A persistent infection is a long-term association between a host and a pathogen in which the pathogen is not completely eliminated and may continue to...

Persistent Infection

A persistent infection is one in which a virus, bacterium or other pathogen is not eliminated by the host immune system and remains within the host for long...

Petri Dish (Petri Plate)

A Petri dish, also called a Petri plate, is a shallow, cylindrical, flat-bottomed dish with a loose-fitting lid used primarily to culture microorganisms in a...

Phage

A phage is a virus that infects bacteria or archaea. Short for bacteriophage, these viruses attach to a specific host cell, inject their genetic material and...

Phenotype

A phenotype is the set of observable characteristics of an organism, including its morphology, physiology, biochemistry and behaviour. These traits are the...

Phenotypic

Phenotypic is an adjective that describes anything related to a phenotype—the observable traits of an organism such as morphology, physiology or behaviour. The...

Photosynthetic Microorganisms

Photosynthetic microorganisms are diverse prokaryotic and eukaryotic organisms capable of converting light energy into chemical energy through photosynthesis,...

Pili

Pili are slender, hair-like appendages extending from the surface of many bacteria that are composed of polymerised pilin proteins. They are distinct from...

Pipette

A pipette is a laboratory instrument designed to accurately transfer specific volumes of liquid, typically measured in microlitres or millilitres. Design and...

Plaque Assay (Viral Plaque Assay)

Plasmid

A plasmid is a small, typically circular DNA molecule that exists independently of a cell’s main chromosomal DNA. These extrachromosomal elements replicate...

Plasmodium falciparum

Plasmodium falciparum is a unicellular protozoan parasite that infects humans and causes the most severe and deadly form of malaria. The parasite is...

Poliovirus 1

Poliovirus 1 is the first serotype of poliovirus, a non enveloped positive sense RNA virus in the Picornaviridae family that causes poliomyelitis. The virus...

Poliovirus 2

Poliovirus 2 is the second serotype of poliovirus, a non‑enveloped positive-sense RNA virus in the Picornaviridae family that causes poliomyelitis. It spreads...

Poliovirus 3

Poliovirus 3 is the third serotype of poliovirus, a non‑enveloped positive-sense RNA virus in the Picornaviridae family that causes poliomyelitis. It spreads...

Portal of Entry

A portal of entry is the anatomical site through which a pathogen enters a host to initiate infection. Common portals include mucous membranes of the...

Portal of Exit

A portal of exit is the anatomical route through which a pathogen leaves its host to enter the environment or another host. It often corresponds to the site...

Powassan Virus

Powassan virus POWV is a tick‑borne, positive‑sense RNA virus in the genus Flavivirus. Its genome is approximately 11 kilobases and encodes a single...

Presumptive Test

A presumptive test is an initial screening procedure used to suggest the presence of a particular microorganism or substance based on characteristic reactions....

Primary Stain

A primary stain is the first dye applied in a differential staining protocol. It colors all cells or targeted structures before subsequent steps differentiate...

Prions

Prions are infectious agents composed solely of misfolded proteins. Unlike viruses or bacteria, they contain no nucleic acid; instead, they are aberrant...

Probiotics

Probiotics are live microorganisms that confer a health benefit to the host when consumed in adequate amounts. Mechanisms and health effects of probiotics...

Prodromal Period

The prodromal period is the stage of an infectious disease that occurs after the incubation phase and before the onset of characteristic illness. During this...