Bacterial Morphology And Structure Flashcards
Living organism prokaryotes
Bacteria
Archaea
Living organism eukaryotes
Algae
Protozoa ( unicellular )
Helminths
Fungi
Shape of coc us
Round
Variation of shape of coccus
Coffee bean
Lancet
Diplococci
Shape of baccilus
Rod shape
Variations of bacillus
Club shape
Comma
Filamentous
Coccobacilli
Shape of spiral
Coiled
Bacteria among the smallest
Rickettsia,
Mycoplasma
Bacteria among the biggest
Bacillus megatorium
Bacillus anthracis
Cyanobacteria
tight or loose attachment
Capsule or slime layer
Encapsulated
Size may be 2-3 times the bacteria
Pneumococci,
Meningococci,
B.anthracis,
C.perfringens
Capsule or slime layer
Hiss stain (clear space), Quellung reaction Antiphagocytic, antigenic, virulence
Complex polysaccharides
Streptococcus, Enterobacter Hyaluronic acid-group A Streptococcus Not essential to life of bacteria
Gives form and rigidity,support to bacteria, vs.osmotic pressure
Absent in mycoplasma
Cell wall-murein sacculus
Cell wall-murein sacculus
principal structural sugar backbone
Peptidoglycan
Cell wall-murein sacculus essential for
Cell wall growth,
sporulation,
cell septation and
competency for transformation
Cell wall-murein sacculus multilayered in
Gram positive
Cell wall-murein sacculus mono layered in
Gram negative
Cell wall of gram positive
Multilayer peptidoglycans
With teichoic acid
No LPS
No lipoprotein and phospholipid
Cell wall of gram negative
Mono layer peptidoglycans
No teichoic acid
With LPS
With lopoprotein and phospholipid
Cell Wall Defective Form
I phase variants
Bacteria w/o cell wall
Protoplast
Bacteria with with outer membrane
Spheroplast
Plasma cell or cytoplasmic membrane
between interior and exterior of cell
- Selectively permeable
- Contain Electron Transport System
- Made up of lipoprotein and lipopolysaccharide
Bacterial nucleus(nucleiod)-
not a true nucleus.
without nuclear membrane and nucleolus.
prokaryotic cell appear as concentrated DNA in cytoplasm bearer of hereditary characteristics
Bacterial cytoplasm
Ribosomes-globular structures,
composed of RNA molecules,
involve in protein synthesis
Storage granules or inclusion bodies-
temporarily holds excess metabolites
-made up of volutin. LAMB stain
metachromatic granules-C.diptheriae
Much granules
- M.tuberculosis
- gram+ granules
organ of locomotion originate from cytoplasmic membrane slender whip like structure, made up of protein flagellin
Flagella
(single polar
Monotrichous
(bundle at one end
lophotrichous
(both ends
Amphitrichous
(all around
peritrichous
(without flagella
Atrichous
-Proteus seen in bacilli
Swarming phenomenon
-used for serologic classification not vital to survival of bacteria, not required for virulence or viability
Antigenic(flagellar H antigen)
Part of flagella that extend into the exterior environment
Filament
Part of flagella that composed of identical sub unit of a protein
Flagellin
)-threadlike structures
Pili(fimbriae
-thousands of pili around bacteria
Common pili
-one or two glycoprotein in a bacterium
Sex pili
Function of pili
adhesion,
sexual,
virulence pili found only in gram negative
found in gram negative bacteria, additional membrane above peptidoglycan layer
Outer membrane
Outer membrane composed of
lipid bilayer,
proteins(porins),
LPS-lipid A,
a polysaccharide rich core and a polysaccharide side chain
Outer membrane
polysaccharide designated as
O antigen
Outer membrane
lipid portion responsible for biologic effects of
endotoxin
-resistant structures which enable bacteria to withstand adverse environmental conditions(viability) found only in few bacteria
Spores(endospores)
_________ bacteria have more complex envelope than _________
Gram negative
Gram positive
Teichoic acid only in
gram + bacteria
Pili seen only in
gram negative bacteria
Spores seen only in certain
gram + bacteria
Kinds of Stains
- Simple or Direct Stain
2. Differential Stain
Color of gram positive
Violet
Color of gram negative
Pink
All bacilli are gram negative except
Mycobacterium,
Corynebacterium,
Bacillus,
Clostridium
All cocci are gram positive except
Neisseria,
Veilonella,
Branhamella Spiral,
All bacteria are non acid fast except
Mycobacterium and
Nocardia(partially acid fast
-Ziehl Neelsen, Kinyoun stain bacteria stains red vs. blue background, resist decolorizer differentiate acid fast from non acid fast, mycolic acid
Acid Fast stain
-background will appear dark ex. India ink-capsule of Cryptococcus neoformans
Indirect Stain
Special or Selective stain-
Dyer-(cell wall) Fisher and Conn(flagella), Dorner (spore), L.A.M.B.stain(metachromatic granules), Hiss (capsule
Non living infectious agents
Viruses
Viroids
Prions