BIO - TERMS - BACTERI Flashcards
A-B toxin
Bacterial exotoxins consisting of two polypeptides.
Actinobacteria
A phylum of gram-positive, chemoheterotrophic bacteria with a high G + C ratio and a signature rRNA sequence.
Antibacterial
A substance that kills or inhibits the growth of bacteria.
antibiogram
Report of antibiotic susceptibility of a bacterium.
atrichous
Bacteria that lack flagella.
bacillus (plural: bacilli)
(1) Any rod-shaped bacterium. (2) When written as a genus (Bacillus) refers to rod-shaped, endospore-forming, facultatively anaerobic, gram-positive bacteria.
bacterial growth curve
A graph indicating the growth of a bacterial population over time.
bactericide
A substance capable of killing bacteria.
bacteriology
The scientific study of prokaryotes, including bacteria and archaea.
bacteriostasis
A treatment capable of inhibiting bacterial growth.
basic dye
A salt in which the color is in the positive ion; used for bacterial stains.
Bergey’s Manual
Bergey’s Manual of Systematic Bacteriology, the standard taxonomic reference on bacteria; also refers to Bergey’s Manual of Determinative Bacteriology, the standard laboratory identification reference on bacteria.
Biological N2 fixation
Enzymatic conversion of N2 to ammonia by free living and symbiotic bacteria.
broad-spectrum antibiotic
An antibiotic that is effective against a wide range of both gram-positive and gram-negative bacteria.
CFU (colony-forming unit)
Visible bacterial colonies on solid media.
Ciprofloxacin
An antibiotic that inhibits bacterial topoisomerases.
Clostridium difficile
Gram-positive anaerobic toxogenic spore-forming bacterium frequently associated with severe colitis following treatment with certain broad-spectrum antibiotics.
coccobacillus (plural: coccobacilli)
A bacterium that is an oval rod.
coccus (plural: cocci)
A spherical or ovoid bacterium.
commensal microbiota, commensal microorganisms
Microorganisms (predominantly bacteria) that normally live harmlessly in symbiosis with their host (for example the gut bacteria in humans and other animals). Many commensals confer a positive benefit on their host in some way.
cyanobacteria
Oxygen-producing photoautotrophic prokaryotes.
Cyanobacteriochromes
Phytochrome-like photoreceptors in cyanobacteria that carry a bilin chromophore.
cyclic dinucleotides (CDNs)
Cyclic dimers of guanylate and/or adenylate monophosphate that are produced by various bacteria as second messengers and detected by STING.
cytotoxin
A bacterial toxin that kills host cells or alters their functions.
death phase
The period of logarithmic decrease in a bacterial population; also called logarithmic decline phase.
decimal reduction time (DRT)
The time (in minutes) required to kill 90% of a bacterial population at a given temperature; also called d value.
deep-freezing
Preservation of bacterial cultures at -50°C to -95°C.
dental plaque
A combination of bacterial cells, dextran, and debris adhering to the teeth.
enteric
The common name for a bacterium in the family Enterobacteriaceae.
Escherichia coli (E. coli)
An intestinal bacterium.
facultative pathogens
Bacteria that replicate in an environmental reservoir such as water or soil and only cause disease if they happen to encounter a susceptible host.
Firmicutes
A phylum of gram-positive bacteria with a low G + C ratio that possess a signature rRNA sequence.
Gas gangrene
A severe type of wound infection caused by collagenase-producing anaerobic bacteria.
ISR (induced systemic resistance)
Allows the plants to endure pathogen attacks, which, without bacterial pre-inoculation, could be lethal. The effect is systemic, e.g., root inoculation with PGPR yields the whole plant nonsusceptible.Thus far Pseudomonas and Burkholderia (Betaproteobacteria) and Bacillus spp. have been shown to elicit ISR.
ketolide
Semisynthetic macrolide antibiotic; effective against macrolide-resistant bacteria
lag phase
The time interval in a bacterial growth curve during which there is no growth.
leukocidins
Substances produced by some bacteria that can destroy neutrophils and macrophages.
lichen
A mutualistic relationship between a fungus and an alga or a cyanobacterium.
log phase
The period of bacterial growth or logarithmic increase in cell numbers; also called exponential growth phase.
Lytic pathway
The reproductive strategy of bacteriophages that destroys their host cell.
membrane filter
A screenlike material with pores small enough to retain microorganisms; a 0.45-μm filter retains most bacteria.
metachromatic granule
A granule that stores inorganic phosphate and stains red with certain blue dyes; characteristic of Corynebacterium diphtheriae. Collectively known as volutin.
microbial fuel cell
A system used to grow bacteria and transfer electrons from their electron transport systems to a wire (electricity).
Microbial mat
A multilayered sheet of microorganisms, mainly bacteria and archaea. Microbial mats grow at interfaces between different types of material mostly on submerged ormoist surfaces, but a few survive in deserts. They colonize environments ranging in temperature from –40∘C to +120∘C.
minimal bactericidal concentration (MBC)
The lowest concentration of chemotherapeutic agent that will kill test microorganisms.
neutrophil extracellular traps (NETs)
A meshwork of nuclear chromatin that is released into the extracellular space by neutrophils undergoing apoptosis at sites of infection, serving as a scaffold that traps extracellular bacteria to enhance their phagocytosis by other phagocytes.
Nitrifier
Chemolithoautotrophic bacteria that conserve energy by transfer of electrons from NH4+ or NO2- to O2.
normal flora
The human microbiota consisting of approximately 1014 bacterial, fungal, and protozoan cells, representing thousands of microbial species.
obligate pathogens
Bacteria that can only replicate inside their host.
oxygenic
Producing oxygen, as in plant and cyanobacterial photosynthesis.
PFU (plaque-forming units)
Visible clearing in a bacterial culture caused by lysis of bacterial cells by bacteriophages.
phage typing
A method of identifying bacteria using specific strains of bacteriophages.
pilus (plural: pili)
An appendage on a bacterial cell used for conjugation and gliding motility.
plate count
A method of determining the number of bacteria in a sample by counting the number of colony-forming units on a solid culture medium.
pleomorphic
Having many shapes, characteristic of certain bacteria.
prebiotics
Chemicals that promote growth of beneficial bacteria in the body.
proteobacteria
Gram-negative, chemoheterotrophic bacteria that possess a signature rRNA sequence.
Prototroph
An organism such as a bacterium that will grow on a minimal medium.
pus-forming bacteria
Capsulated bacteria that result in pus formation at the site of infection. Also called pyogenic (pus-forming) bacteria.
quorum sensing
The ability of bacteria to communicate and coordinate behavior via signaling molecules.
rapid identification methods
Bacterial identification tools that perform several biochemical tests simultaneously.
root nodule
A tumorlike growth on the roots of certain plants containing symbiotic nitrogen-fixing bacteria.
spheroplast
A gram-negative bacterium treated to damage the cell wall, resulting in a spherical cell.
spirillum (plural: spirilla)
(1) A helical or corkscrew-shaped bacterium. (2) When written as a genus, refers to aerobic, helical bacteria with clumps of polar flagella.
spirochete
A corkscrew-shaped bacterium with axial filaments.
stationary phase
The period in a bacterial growth curve when the number of cells dividing equals the number dying.
streptococci (singular: streptococcus)
(1) Cocci that remain attached in chains after cell division. (2) When written as a genus, refers to grampositive, catalase-negative bacteria.
Streptomycin
An antibiotic that binds to the small (30S) subunit of bacterial ribosomes.
Sulfonamides
Bacteriostatic agents that inhibit bacterial folate synthesis.
superbug
Bacterium resistant to a large number of antibiotics.
thermal death time (TDT)
The length of time required to kill all bacteria in a liquid culture at a given temperature.
Trimethylamine
A fish-smelling product of bacterial glycine degradation.
tuberculin skin test
A skin test used to detect the presence of antibodies to Mycobacterium tuberculosis.
Urobilinogens
Uncolored products formed from bilirubin by intestinal bacteria.
Urobilins
Colored products formed from bilirubin by intestinal bacteria.
Viable but nonculturable
(VBNC) A bacterial cell in the VBNC state may be defined as one which fails to grow at the routine bacteriological cultivation conditions under which it would normally grow but which is in fact alive and has still metabolic activity. This can be understood as a stress response. Under favorable conditions such a cell can return to the culturable state. This is the definition which is commonly accepted for the behavior of hygienically relevant microorganisms.
vibrio
(1) A curved or comma-shaped bacterium. (2) When written as a genus (Vibrio), a gram-negative, motile, facultatively anaerobic curved rod.
Viral shunt
Conversion of bacterial biomass to DOM and cellular debris through viral lysis.
zone of inhibition
The area of no bacterial growth around an antimicrobial agent in the disk-diffusion method.
λ Phage
A temperate bacteriophage of Escherichia coli.
