Medical MicroBio Ch. 4

Thin sheet of lipids and proteins that controls what comes in and out

• Unmoving, resting, cells produced by gram positive genus (ex. clostridium)

• Hardiest of all life forms

• Dehydrated, inactive cells with thick coat, and almost immortal

• Resistant to ordinary cleaning products

• Have a two phase life cype called sporulation

formation of endospores

• Vegetative cell

  • Metabolically active and growing

  • Are easier to treat with antibiotics and cleaning supplies

• Endospore

  • Occurs when exposed to adverse environmental conditions

  • Highly resistant and very long term survival

  • Able to withstand many environments and conditions

return of an endospore to the vegetative growth state

• Coccus = spherical shaped

• Bacillus = Rod-shaped

• vibro = gently curved

• Filamentous

• Spirillum = Helical, comma, twisted rod

• spirochete = spring like

cocci:

• Singles

• Diplococci–in pairs

• Tetrads–groups of four

• Irregular clusters

• Chains

• Cubical packets (sarcina)

Bacilli:

• Diplobacilli

• Chains (Streptobacilli)

• Palisades- looks like a picket fence

• Classification of bacteria based on genetic information

• Includes archaea and bacteria, and 25 different phyla

• Classification of bacteria based off cell wall structure, shape, arrangement, and physiological traits

• TINY, gram negative bacteria

• Pathogenic

• Obligate intracellular pathogens

• Cannot survive outside the host cell

• Tiny, obligate intracellular parasites

• Transmitted through skin to skin contact

• Chlamydia trachomatis = severe eye infection and one of the most common sexually transmitted diseases

• Chlamydia pneumoniae = lung infections

Live in the most extreme habitats in nature

Methane producers

Live in high temperatures

Requires high salty environment to grow

Loving cold temperatures

A circular chromosome or nucleoid composed of condensed DNA molecules containing genetic information

• Tiny particles made of protein and RNA

  • Sites of protein synthesis

Water-like solution filling the entire cell

Single layer or protein for protection or attachment

Extra membrane containing lipopolysaccharide

Semirigid casing providing support and shape

Long fiber proteins contributing to shape of cell

• Small double stranded DNA containing extra genes

  • Can be used for antibiotic resistance

• Rotate 360 degrees for motility

• 3 parts

  • Filament = long thin structure composed of protein

  • Hook = curved sheath

  • Basal body = stack of rings in cell wall

Single flagella at one end

Small bunches emerging from the same site

flagella at both ends

Flagella all over surface

• Chemical stimuli

  • Chemotaxis = toward or awy from chemical concentrations

• Light stimuli

  • Phototaxis = toward or away from light

• Counterclockwise motion = smooth linear run

  • Clockwise motion = tumble

• Internal flagella

• producing cellular motility by contracting and imparting twisting or flexing motions

Fine, hair-like bristles extending from the cell surface to help adhesion

Rigid tube structure made of pilin protein

only found in gram (-) cells ; have twitchlike movements

join bacterial cells for DNA transfer

• Coating of molecules outside of the cell wall; made of sugars and/or protein

• Protect cells from dehydration and nutrient loss

• Phagocytize WBCs to help with causing disease

• Attaching cells can create biolfilms

• Types

  • Slime layer

    • Loosely organized and attached

  • Capsule

    • Highly organized, tightly attached

• Cooperative associations among microbial groups

• Community of cells that evolves and undergoes specific adaptations for its habitat

• Quorum sensing

  • Individual species alters gene expression in cooperation with other cells in the biofilm

• Thick cell wall composed of peptidoglycan and cell membrane

• retains crystal violet dye and appears purple

• 20-80nm thick peptidoglycan layer

• Peptidoglycan layer contains teichoic and lipoteichoic acids to maintain wall, move cations, and stimulate immune response

  • May have a periplasmic space between the membrane and wall

• Has an outercell membrane, thin pepdidoglycan, and cell membrane

• loses crystal violet dye and appears red from safranin

• Has an inner membrane, outer membrane, and periplasmic space

• Has a thin peptidoglycan layer

  • Outer membrane has lipopolysaccharides (LPS) which can release toxins

• Primary component of cell walls

  • Alternating NAG and NAM glycan chains

• Developed by a scientist named Gram who helped to differentiate between two different types of bacteria

• Differential stain distinguishing cells with a gram positive cell wall from cells with a gram negative cell wall

• When treated with ethanol Gram-positive-retain crystal violet and stain purple

• When treated with ethanol Gram-negative-lose crystal violet and stain red from safranin (reddish-pink) counterstain

Used to diagnose infections caused by bacteria without a typical cell wall structure

gram negative cell walls

mainly gram positive with low G+C content

gram positive with high G+C content

• Rocky mountain spotted fever; potentially fatal disease that's usually caused by the bite of a tick infected with rickettsia group bacteria.

typhus