First Exams topics

• Examples of microorganisms

  • staphylococcus epidermidis - beneficial, prevent more harmful bacterias from living
  • penicillium notatum - beneficial, source of penicillin
  • gymonodinium catenatum - harmful, dinoflagellate, causes red tide
  • naegleria fowleri - harmful, brain eating bacteria
  • sars cov-2 - harmful, cause of 3 year pandemic
• robert hooke

  • invented microscope in 1665
  • brought a lot of improvements in drug discovery
• antonie van leeuwenhoek

  • improved microscope
  • used the term animalcules
  • learned to look and mount specimen without killing it
• spontaneous generation

  • states that micoorganisms sprung out of nothing
• Spallanzani's experiment

  • biogenesis - living things came from living things
• pasteur's experiment

  • supported biogenesis
• John Snow

  • tracks cholera epidemic in London
  • microorganisms can cause epidemic
• Ignaz Semmelweis

  • discovered a relationship between doctor's soiled hands and patient infection
• Louis Pasteur

  • introduced pasteurization
  • established temperature range necessary to kill bacteria
• Florence Nightingale

  • Improved air and water quality in hospitals
• Louis Pasteur

  • proved that spoilage and infection is caused by microorganisms
• Joseph Lister

  • used carbolic acid or phenol as antiseptic, reducing infection rate from 60% - 4%
• Louis Pasteur

  • coined the term microbiology
• Robert Koch

  • discovered that intense heat destroys all bacterial contamination
• Fannie Hesse

  • proposed gelatin like algae derivative (Agar) as pure culture medium
• Hans Christian Gram

  • Gram negative, Gram positive
• Richard Petri

  • invented petri dish
• Royal Microscopy society

  • standardization of microscopy
• three domain system

  • archaea
  • eukarya
  • bacteria
• Bacteria

  • Nucleus - none
  • Body type - unicellular
  • cell wall - peptidoglycan
  • cell membrane - ester-linked lipids with D-glycerol (straight chain)
  • ribosomes - 70s
  • introns and histones - none
  • sensitive to antibiotics - yes
• Archaea

  • Nucleus - none
  • Body type - unicellular
  • cell wall - different type of polysaccharide
  • cell membrane - ether-linked lipids with L glycerol (branched chain)
  • ribosomes - 80s
  • introns and histones - some are present
  • sensitive to antibiotics - similar sensitivity to that of eukarya
• Eukarya

  • Nucleus - present
  • Body type - multicellular / unicellular
  • cell wall - chitin / cellulose
  • cell membrane - ester-lined lipids with proteins (straight chain)
  • ribosomes - 80s
  • introns and histones - present
  • sensitive to antibiotics - distinct sensitivity profile
• Gram-Negative Bacteria

  Label:

  A) diplococci

  B) coccobacilli

  C) bacilli

  D) aerobic

  E) N. meningitidis

  F) N. gonorrhoeae + Moraxella

  G) b. pertussis, pasteurella, brucella, F. tularensis,

  H) comma-shaped

  I) grows in 42C

  J) grows in alkaline media

  K) urease producing

  L) C. jejuni

  M) v. cholerae

  N) h. pylori

  O) pseudomonas

  P) shigella, yersinia

  Q) salmonella, proteus

  R) citrobacter, serratia

  S) e. coli, klebsiella, enterobacter

  
• Gram-positive bacteria

  • label

  A) bacilli

  B) cocci

  C) branching filaments

  D) listeria, bacillus, corynebacterium

  E) clostridium

  F) nocardia

  G) actinomyces

  H) streptococcus

  I) staphylococcus

  J) s. pneumoniae

  K) s. mutans, s. mitis

  L) s. agalactiae

  M) s. bovis

  N) s. pyogenes

  O) s. aureus

  P) s. saphrophyticus

  Q) s. epidermidis

  R) e. faecium, e. faecalis

  
• Viruses

  • no cellular structure
  • nucleic acid + protein coat
  • some have lipid envelope
  • intracellular parasites
  • no enzymes to replicate own nucleic acid
• viroids

  • RNA w/o proteins
  • does not encode proteins
  • virus-like in terms of having nucleic acid
  • incommplete virus (needs to have at least a single or double stranded RNA/DNA and a protein_
• prions

  • no nucleic acid
  • infectious protein
  • mad cow disease
  • proteins may be with the exact amino acid sequence
• archaebacteria

  • no pharmaceutical value
  • unicellular
  • prokaryote
  • unusual/lack cell walls: pseudo murein instead of peptidoglycan
  • different cell wall, cell membrane and ribosome component
• size

  • monomorphic - same shape all throughout its lifetime
  • pleomorphic - adopt different shape in their lifetime
• cocci

  • coccus - single
  • diplococci - cocci divide and remain together to form pairs
  • staphylococci - divides into random planes to form clustered clumps
  • streptococci - long chains of cocci (repeated divisions in one plane)
  • tetrad coccus - square groups of four cells
  • sarcina coccus - cocci divide into three planes producing cubical packets of eight cells
• bacilli

  • coccobacillus - between being cocci and bacillus
  • bacillus - rod shape
  • diplobacilli - in pairs
  • streptobacilli - chains
  • palisades - bundled bacilli
• others

  • club rod
  • vitrio
  • spirillum
  • helical form
  • spirochete
  • filamentous
• appendaged bacteria

  • shape of the cell looks like tail
  • different from the tail itself
  • e.g. hypha, stalk
• shape

  • star shaped
  • rectangular shae
• structures external to cell wall

  • glycocalyx - glycopeptide that adds virulence to bacteria, capsule (Addition to cell wall), slime layer (organized loosely attached to cell wall)
  • axial filaments - spirochetes and endoflagella - bundles of fibrils that arise at the end of the cell, beneath an outer sheath, a fiber part of the cell membrane
  • flagella - atrichous, peritrichous, cephalotrichous, monotrichous, lophotrichous, amphitrichous
  • pili - motility and dna transfer
  • fimbria - biofilm formation, shorter than flagella
• cell wall

  • determines sensitivity/effect of specific antimicrobial agent
  • crystal violet iodine as dye
• peptidoglycan layer

  • contains carbs and peptides
  • N-acetyglucosamine, N-acetylmuramic acid
  • amino acids : l-ala, d-glu, l-lys, d-ala
• gram positive

  • stains positively
  • thick peptidoglycan layer
  • single periplasmic space
  • destroyed in heat (releases exotoxins when heated)
  • weaker resistance towards lysozymes
• gram negative

  • stains negatively in gram staining
  • color pink in second dye, safrnain
  • thin peptidoglycan layer but has additional outer membrane, lipoproteins, lipopolysaccharides, and porin channels
  • releases endotoxin and exotoxins when heated
  • high resistance with lysozymes
  • resistant to penicillin and sulfanilamide
• acid-fast bacteria

  • gram positive
  • positive due to the mycolic acid in their cell wall
  • when de colorized the bacteria with no mycolic acid will remove the carbolfuchsin stain