General Bacti/Myco Flashcards
Prokaryotes have a chemically complex ___ ___.
cell wall
Prokaryotic form of reproduction
Asexual. Binary fission.
Prokaryotic ribosomes
small, 70s
Prokaryote chromosome type
single, haploid, circular
*Exceptions: Leptospira has 2 circular chromosomes. Borrelia burgdorferi has linear chromosomes.
What type of bacterium has no cell wall?
Mycoplasma
What characteristic of bacteria makes it easy for nutrients to penetrate from the surface to all parts of the cell?
Large surface to volume ratio (3:1)
The bacterial cell wall is made up of what?
Peptidoglycan
*Gram stain
Mycobacteria have what in their cell wall?
Mycolic acid (virulence factor)
*Acid fast stain
What class of bacteria has lipoteichoic acid in the cell wall, making them more antigenic?
Gram positive
What class of bacteria is resistant to physical disruption/drying, but is susceptible to ionic detergents?
Gram positive
What class of bacteria has Lipopolysaccharides (LPS) surrounding the cell wall?
Gram negatve
What are the 2 components of LPS in Gram negative bacteria?
Lipid A: endotoxin
Polysaccharide chain: antigenic
What class of bacteria is susceptible to physical disruption/drying, but resistant to ionic detergents?
Gram negative
Spirochetes have what type of flagellum?
Endoflagella in the periplasmic space (corkscrew motion)
What type of hair-like bacterial accessories help with adherence and antigenicity, as seen with E. coli K88 and K99?
Pili or fimbriae
3 main functions of the polysaccharide capsule:
Nutrient reserve
Adherence
Evasion from phagocytosis
Clostridium and Bacillus spp can form and release _______ to promote survival via cryptobiotic dormancy during poor environmental conditions.
Endospores
Endospores are formed _______.
Intracellularly
Eukaryotic, heterotrophic, and strictly aerobic microorganisms
Fungi
Fungi have a cell wall made of _____.
Chitin
2 types of fungi
Unicellular yeasts Multicellular molds (branching hyphae)
Methods of fungal reproduction
Sexual (spores)
Asexual (spores, budding, fragmentation)
T/F: Fungi are easily killed with antimicrobials.
False! They are resistant!
T/F: the majority of fungi are saprophytes and are non pathogenic, so it’s much more common to suffer from a bacterial infection than a fungal infection/
True :-)
Mycosis:
Fungal tissue invasion
*dermatomycoses
Mycotoxicosis:
Fungal toxin production
*ingestion of fungal toxins
What mechanism of fungal infection is responsible for chronic pulmonary disease in cattle and horses?
Ability to induce hypersensitivity
Do most pathogenic bacteria live inside or outside the cell?
Outside
Rickettsia and Chlamydia are examples of the few bacteria that are _______ _______, and need a host to replicate.
Obligate intracellular
Mycobacterium and Rhodococcus are examples of some bacteria that can survive intra- or extracellularly, known as ______ ______.
Facultative intracellular
_______ pathogens are high in number, cause non-specific disease and have a low virulence
Opportunistic//facultative
______ pathogens are low in number, cause a distinct disease and and have a high virulence.
Obligate
Type of infection in which the individual does not show signs, but is able to infect others, and may resist reinfection.
Subclinical disease
Iceberg concept of disease from base to tip
Exposure without infection > subclinical disease > mild illness > severe disease/death
T/F: all infectious diseases are communicable
FALSE
What are the factors generally required for bacterial growth?
Iron, sugar, oxygen (some)
What are the phases of the bacterial growth curve?
- Lag phase (eating and preparing to reproduce)
- Log phase (exponential growth)
- Stationary phase (growth=death)
- Decline/death (nutrients depleted = cell death)
Heat labile toxins that are produced by bacteria and released on target cells.
Exotoxins
Heat stable cell wall components that induce inflammation by stimulating the immune system
Endotoxins
Three ways that bacteria can transfer virulence factors:
Transduction (by phage)
Transformation (uptake of free DNA)
Conjugation (by direct contact)
