7. COCCI- spherical or oval cells- eg. Staphylococcus
BACILLI- rod shaped- eg. E.coli, Brucella,
COCCOBACILLI-length is same as width, eg.Klebsiella
SPIROCHAETES- slender flexuous spiral forms. Eg.
Treponema
VIBRIOS- comma shaped
SPIRILLA- rigid spiral forms
ACTINOMYCETES- branching filamentous bacteria
resembling fungi
MYCOPLASMA- round or oval bodies & interlacing
filaments (cell wall deficient)
RICKETTSIAE and CHLAMYDIAE- small obligate
parasites classified as viruses, but included in bacteria
due to presence of cell wall, bacterial enzymes and
structural similarities with bacteria
8. STREPTO- chains
DIPLO- pairs
STAPHYLO- clusters
TETRADS- groups of four eg. Micrococci
SARCINA- groups of eight
CUNEIFORM- chinese letter pattern eg.
Corynebacterium
9.
10.
11. Tough & rigid structure
Made of peptidoglycan –
mucopeptide(murein) composed of N-
acetyl muramic acid & N- acetyl
glucosamine alternating in chains cross
linked by peptide subunits
12. tightly cross linked peptides- d-alanine & d-
glutamic acid
Thickness- 18-80 nm & constitutes 40-80% of
the dry weight
Techoic acid- water soluble polymers of
glycerol phosphate or ribitol phosphate
residues
two types – wall techoic acid-ribitol
&membrane techoic acid- glycerol
functions- cell wall stability, association of
wall with membrane, adherence, reproduction
13. Polysaccharides- mannose, arabinose ,
rhamnose, glucuronic acid & mannuronic
acid
Thick peptidoglycan layer
S LAYER- protein or glycoprotein
molecules that self assemble on the outer
surface of the organism.
Protect from stressful environments,
inhibit phagocytosis, contribute to
virulence
15. Lipoprotein layer- connects peptidoglycan
to outer membrane & stabilizes the outer
membrane
• Periplasmic space- space between inner&
outer membranes containing the
peptidoglycan layer and gel like solution
of proteins & membrane derived
oligosaccharides
• Thin peptidoglycan layer
16.
17.
18. Accounts for the shape of the cell
Protects the cell against osmotic damage
Confers rigidity
Cell division
Target site for antibiotics, lysozymes,
bacteriophages
Carries bacterial antigens
19. Plasmolysis
Microdissection
Reaction with specific antibody
Electron microscopy
Indirect methods- Grams staining & Acid fast
staining, fluorescent staining for acid fast
bacteria
20.
21. MYCOPLASMA- stable oval or round forms
L- FORMS- observed in streptobacillus
monoliformis. Induced by penicillin
PROTOPLASTS- gram positive bacteria when
placed in hypertonic saline
SPHEROPLASTS- gram negative bacteria
when subjected to penicillin. Some cell wall
material is retained
PLEIOMORPHIC & INVOLUTION FORMS-
swollen & aberrant forms resulting from
ageing
22. 5-10nm thick elastic membrane beneath the cell wall
separating it from cytoplasm
Composed of lipoprotein. Sterols absent except in
mycoplasma
Permeases- membrane associated carrier proteins
FUNCTIONS- selective permiability and transport of
solutes
electron transport and oxidative phosphorylation
excretion
bearing the enzymes and carrier molecules for
biosynthesis
23.
24. Colloid of organic and inorganic solutes in
viscous watery solution
RIBOSOMES- centres of protein synmthesis.
Composed of rRNA of size 10 - 20nm with a
sedimentation constant of 70S
MESOSOMES- vesicular, convoluted
invaginations from plasma membrane.
more prominent in GPB
principal site of respiratory enzyme
site of synthesis of cross wall septa during
binary fission
25. VOLUTIN- ( BABES ERNST GRANULES)
highly refractile, strongly basophilic bodies
consisting of polymetaphosphate.
stained by Albert or Neisser stain
present in diphtheria bacilli
reserve of energy
POLYSACCHARIDE- stained with iodine
LIPIDS- stained with sudan black
VACUOLES- fluid filled cavities covered by
a membrane
26. Contains the cell’s genome made of a single
molecule of double stranded DNA arranged in
the form of a circle . Measure about 1mm
27. Extranuclear genetic material
Transmitted to daughter cells either by
binary fission or from one bacterium to
another by conjugation or bacteriophage
Confer properties like toxigenicity and
drug resistance
28. - acid or ribonuclease hydrolysis and
subsequent staining of nuclear material
by Feulgen stain specific for DNA
appear as oval or elongated bodies
Binary fission and conjugation
29. Amorphous viscid bacterial secretion
surrounding the cell wall
Loose undemarcated secretion – slime layer
or glycocalyx
Sharply defined structure- capsule
30. Homo or hetero Polysaccharides made of
hexose and pentose sugars plus ribitol,
glycerol and other sugar alchohols
synthesised by the cell membrane with
enzymes- glucosyl and fructosyl
transferases producing an insoluble
glucan matrix
Anthrax bacilli- polypeptide
33. Negative staining- india ink or nigrosin-
capsule appears as a clear halo around
the cell
Positive staining- B.anthracis-
polychrome methylene blue- McFadyean
capsule stain
35. Serological methods- Quellung test
(Neufeld reaction)- loopful of
pneumococci + antiserum(
antipneumococcal rabit sera)
observe in oil immersion under phase
contrast microscope
capsules become refractile & visible ,
seperated from the coccal bodies by the
width of the capsule
36.
37.
38. Long, filamentous appendages arising at the
cytoplasmic membrane, protruding through
the cell wall into the surrounding medium
39. monotrichous- single polar flagella- Vibrio
amphitrichous- single flagellum at both the
poles- A.fecalis
lophotrichous- tuft of flagella at one or both the
ends- Spirilla
peritrichous- flagella all around the cell- S.typhi
42. SIZE- 5-20µm long, width-13-17nm
PARTS- FILAMENT- made of flagellin
semirigid, forms a left handed helix and exits
the cell
HOOK- Acts as a sleeve from which the
filament emerges
transmits rotatory motion from basal body to
filament
BASAL BODY- consists of M,S,P,L rings
connected by a rod shaped structure
in gram positive bacteria only 2 rings are seen
43.
44. PHASE VARIATION- 2 types of flagella
due to expression of genes coding for 2
different flagellin proteins in the same
bacteria
flagellar antigen- H-antigen
Endoflagellum- arises from one pole,
wraps around the cell body interior to
the cell. Eg:- vibro, spirochaetes
45. flagellar antigen H used for identification
MOTILITY- impart spinning movement
driven by the flow of protons into the cell
down the gradient produced by the primary
proton pump
CHEMOTAXIS, AEROTAXIS, PHOTOTAXIS,
ELECTRON ACCEPTOR TAXIS- movement
of the cell towards the source of attracant by
swimming, tumbling and reorienting itself to
the attractant
46. DIRECT METHOD- dark field microscopy &
electron microscopy
INDIRECT METHODS- Swarming growth of
proteus
craiges tube method- spreading of bacteria on
semi solid agar
hanging drop preparation-motilty of the
bacterium examined on a wet film under high
power
mannitol motility medium- fanning
wet mount preparation
47.
48. Hair like appendages protruding from the cell
as straight filaments
Found in many gram positive and some gram
negative bacteria
SIZE- 0.1-1.0µm length, 10nm thick. Each
cell possesses 100-500 fimbriae
49. ARRANGEMENT- peritrichous &
helically arranged
Possess antigenic property
Composed of a protein fimbrillin(pilin)
which form hollow tubes in the cell
membrane
ADHESINS- minor proteins on the tips of pili
responsible for attachment.
50. Common pili- six types- I- responsible
for adhesion and are mannose
sensitive
type II- mannose resistant
Sex or fertility pili- long pili present in
male bacteria of size 18-20 nm & are 1-
4 in number. Helps in forming
conjugation tubes for transferring
genetic material to female cells
51. TWITCHING- motility established by
pili. Bacterium moves in the direction of
the adhering tip resulting in surface
motility. Seen because the pili donot
rotate & lack a basal body
53. Electron microscopy
Haemagglutination- tile test- drop of dense
bacillary deposit + red cell suspension on a
white tile at 3-5ºC .
develops coarse clumping within a few
seconds
mannose 0.5% inhibits type I fimbrial
haemagglutination
RBC’s of guinea pigs, fowl, horses & pigs
agglutinate strongly, sheep and human blood
weakly and ox blood scarcely
54.
55.
56. Spherical or oval structures formed within the
bacterial cell
Represents the resting or dormant phase
formed under unfavourable conditions related
to depletion of exogenous nutrients
Also called as endospores
In sporulation each vegetative cell forms only
one spore and during subsequent germination
each spore gives rise to only one vegetative
bacterium
Bacillus and clostridia species form spores
57. CORE- it’s the spore protoplast. Contains nucleus,
protein synthesizing apparatus, energy generating
system based on glycolysis.
Vegetative cell enzymes are increased in amount
Contains large amounts of calcium dipicolinate
responsible for resistance
SPORE WALL- innermost layer surrounding the
inner spore membrane. Made of peptidoglycan and
forms cell wall
CORTEX- Thickest layer made of peptidoglycan
sensitive to lysozyme. Role in spore germination
58. COAT- keratin like protein containing
many intermolecular disulphide bonds.
Impermeable and provides resistance to
antibacterial agents
EXOSPORIUM- composed of lipids,
proteins and carbohydrates. Consists of
paracrystalline basal layer and hair like
outer region
59.
60. Process by which spores are formed. Involves
production of many new structures , enzymes
and metabolites along with disappearance of
many vegetative cell components -
differentiation
Spore composition determining genes are
activated by association of RNA polymerase
core protein with sigma factor
Sporulation process takes about 7hrs under
laboratory conditions
61.
62. ACTIVATION- spore coat gets damaged
INITIATION- triggered by L-alanine or
adenosine. Autolysin is secreted that degrades
the cortex peptidoglycan. Water is taken up
releasing calcium dipicolinate and degrades
various spore components by hydrolytic
enzymes
OUTGROWTH- degradation of cortex and
outer layers results in emergence of new
vegetative cell
63. NON BULGING- diameter of the spore is
same as or less than the width of bacteria
BULGING- diameter is wider than the
bacillary body
POSITION- central
subterminal
terminal
64. GRAMS STAIN- spore appears as clear
unstained ares within the cell
ZIEHL NEELSON METHOD- 0.25%
sulphuric acid is used. Stain red &bacilli
blue
MALACHITE GREEN STAIN-5%
aqueous solution of malachite green-
1min
saffranin or basic fuschin – 30sec
spores- stain green& bacilli red
65.
66. Indicator for sterilization-
G.stearothermophilus is destroyed by
autoclaving, hot air oven
Ethylene oxide sterilizer- B.atrophaecus