first colloq Flashcards
Microbiology is divided into:
Bacteriology
Parasitology (protozoa, metazoan)
Mycology
Virology
Classification:
dividing the organisms into taxa on tha Basis of certain characteristics
is part of systematics
Systematics:
grouping of the organisms on the Basis of certain characteristics
Five kingdoms
Animalia Plantae Fungi Protista (protozoa) Monera (prokaryotes)
3 domains
Archaea (pro)
Bacteria (pro)
Eukarya
Taxonomy of bacteria
Domain Kingdom Phylum Class Order Family Genus Species
Strain vs Clone
Strain: genetic variant or subtype of certein microorganism
Clone: genetic copy of a cell procuded asexually
Classification of viruses
DNA
- double stranded (enveloped and unenveloped)
- single stranded (unenveloped)
RNA
- +RNA (unenveloped and unenveloped)
- -RNA (enveloped)
- +/- RNA (double capsid)
- RNA via DNA (enveloped)
Classification of fungi
- zygomycotica (produce zygotes)
- dikaryomykotica (Extended dikaryotic Phase
- -> Basidiomycotina: in sac called basidium –> basidiospores
- -> Ascomycotina: in sac calles Ascus –> ascospores
- Deuteromycotina (fungi imperfecti)
Classification of protozoa
mama Papa, paula erreicht aber sonst clowns
- Metamonada (flagella)
- Parabasala (flagella)
- Percolozoa (flagella)
- Euglenozoa (flagella)
- Amoebozoa (move like amebea)
- Sporozoa (non-motila)
- Ciliopphora (have cilia)
Morphology of cocci
2 --> diplococci more in a row --> streptococci 4 --> tetrad 8 --> sarcinae a lot in one place --> staphylococci
Classification of rods
according to :
- length (Long, short, very short(coccobacilli))
- Ends (rounded, sharp, rectangle, ovoid, club)
- Diameter (thin, thick)
Morphology of spiral bacteria
vibrio
Spirillum
spirochete
Spirochetes pathogenic for humans
Treponemes
Borrelliae
Letropires
Classification of viruses
rod shaped
complex shaped
filamentous
Classification of fungi
Yeast
pseudohyphae
Hyphae
Eukaryote vs Prokaryotes
–> look at picture
Bacerial cell sheath (von innen nach außen)
Cytoplasmic membrane
Cell wall
Capsule (slime layer)
Cytoplasmic membrane composition and its functions (5)
Lipid bilayer with proteins
- Transport of metabolites
- Synthesis of cell wall components
- secretion
- sensory
- electron transport
Cell wall functions (3)
- shape
- protection from water
- diffusion
Cell walls of gram + and gram - bacteria
GRAM +
- peptidoglycans with (teichoic Acid, proteins, lipoteichoic Acid)
GRAM -
- lipopolysaccharide (o polys., core polys, Lipid A)
- peptidoglycans with proteins
Capsule and its functions (3)
slime layer composed of water and polsaccharide
- inhibits phagocytosis
- adhesion
- water storage
Bacterial flagella
Filament of Twisted fibrils
- composed of basal Body, hook, Filament
- in gram +: basal Body goes throiugh cytoplamsic membrane
- in gram -: basal Body goes through cytoplasmic mebrane and cell wall
Classification of Bacteria according to flagella
- Monotrichous (fastest)
- Amphitrichous
- peritrichous
- Lophotrichous
Bacterial pili
- hair like
- composed of pilins
two Kinds:
- fimbriae: for adhesion, Shorter
- F-pili: longer, for Transfer of genes
Cell wall structure of mycobacteriae
- mycolic Acid
- arabinogalactan
- peptidogylcan
- lipoarabinomannan goes through it vertically
Life cycle of rikketsiae
- attach to host cell and are andocytosed
- degrade endosome membrane by phospholipase
spotted Fever Groups: multiply in nucleus and cytoplasm, are able to produce actin and are released through Long cytoplasmic processes
typhus Group: multiply only in cytoplasm, are released through cell death
Life cycle of chlamydiae
- infectious EB attach to microvilli
- take 6-8h to become reticulate bodies
- RB replicate by binary fission
- RBs take 18-24h to become EB
- EBs are released
Properties of mycoplasmas
- smalles free Living Bacteria (coccoid or rods)
- dont have a cell wall –> resistance to Penicillin
- cytoplasmic membrane with sterols
- grow on artificial surfaces
Bacterial spores
- dehydrated, Multi shelled strucutre
- dormant stage where Bacteria can survive extreme conditions
- has copy of chromosome
- low conc. of proteins and ribosomes
- high conc. of Calcium Bound to dipicolinic Acid
- some are gram + but never gram -
Layers of spores
- Exosporium
- Protein coat
- Outer membrane
- Cortex
- Spore wall
- inner membrane
- Core
Bacterial sporogenesis
- spore mRNA is transcribed, other mRNA turned off
- Dipicolinic Acid is produced
- duplication of chromosome
- Septum is formed
- two membranes are formed (cytoplasmic and Septum)
- two membranes surrounded by Cortex
- Cortex is surrounded by protein coat
Germination of bacterial spores
- disruption of outer cieat by mechanical stress, pH, heat..
- requires water and triggering nutrient
- takes 90 min
koch’s Postulates of infectious disease
1- Microorganism is present in Organs suffering from disease
2- Microorgabism must be isolated and grown in pure culture
3- Microorganism should cause disease in healthy organism
Differential stains examples
- Gram stain. + is Crystal violet and - is saffranin
- Schaeffer-Fulton: spore stain
- Ziel-neelsen fast stain: red –> carolfuchsin, blue –> methylene blue
- wirtz: endospores –> Malachite green, vegetative cells –> safranin
Parts of microscope
- blue filter; filters out Long wavelengths
- condenser: converges light beams
- Iris diaphragm: controls amount of light
- Objective lens: magnifies
- Ocular lens: magnifies
Acid-fast baceria
- cell wall is thick becuase 60% are made of Lipids
- carbolfuchsin binds to cytoplasm
- grow slowly because Lipids hinder nutrients to enter cell
- non-motile, non-spore forming, Aerobic, rods
Luis Pasteur
- came up with pasteurization
- came up with support for germ Theory
- vaccination for antrhax and rabies
Robert Koch
- idintified causative agents of tuberculosis, cholera, Anthrax
- founder of modern bacteriology
- delevoped staining of bacteria
Dark field microscopy
- condenser after light source –> only scattered light hits the specimen
- over specimen there is objective lens collecting rays
- used to observe light Bacteria Motion
Electron microscope
- light source and beam of accelerated electron
- wavelength of electron is 100,000x Shorter than Photon –> higher resolution
Stereoscopic microscope
- uses light reflected from Surface (non transmitted through)
- 2 optical paths with 2 objectives and eyepieces
Phase contrast microscope
- 2 components: annular ring in condenser and Phase ring in objective
- light passes through specimen –> Phase shift –> refraction
- refracted light hits Phase ring –> Region will be dark
- good for examination of internal details
Actinomyces
- facultative anaerobic, gram +
- not Acid fast –> stain blue in Ziehl neelsen
- grow slow
- produce chronic, slow infections
- rod shaped but together form hyphae
