• UNICELLULAR
• LIGHT MICROSCOPIC - 0.2 - 2
MICROMETERS IN DIAMETER; 2 - 8
MICROMETERS IN LENGTH
• CELL SHAPE AND ARRANGEMENT
• PROCARYOTIC IN CELL STRUCTURE

• THE GLYCOCALYX - CAPSULE AND SLIME
LAYER
– PRODUCED WITHIN THE CELL AND
SECRETED EXTRACELLULARLY
– CAPSULE
• CARBOHYDRATE - POLYSACCHARIDE
• WELL ORGANIZED
• LAYED DOWN EVENLY AROUND THE
CELL WALL
• FIRMLY ATTACHED

CAPSULE (CONT.)
• NOT EASILY PENETRATED

SLIME LAYER
• NOT WELL ORGANIZED
• EASILY PENETRATED

ADVANTAGES OF HAVING A CAPSULE
• ADHERENCE
• NUTRITION SOURCE
• PROTECTION
– ANTIBIOTICS
– IMMUNE SYSTEM
– NUTRIENT AND WATER LOSS

THE BACTERIAL CELL WALL
• MAJOR COMPONENT OF MOST
BACTERIAL CELLS
• MAINTAINS THE SHAPE AND INTEGRITY
OF THE CELL
• PRESENT IN ALL PROCARYOTIC CELLS
EXCEPT THE MYCOPLASMAS
• MAJOR DIFFERENCES IN CELL WALLS
DEMONSTRATED BY THE GRAM STAIN

• SINGLE LAYER
• UP TO 90% PEPTIDOGLYCAN

• SEVERAL LAYERS SEEN

• INTERESTING CHARACTEIRTICS OF THE
AMINO ACIDS SEEN IN PEPTIDOGLYCAN
– D-AMINO ACID ISOMERS VS. L-AMINO
ACID ISOMERS
– DIAMINOPIMELIC ACID - AA FOUND
ONLY IN PEPTIDOGLYCAN
• INTERESTING CHEMICALS THAT AFFECT
THE CELL WALL OF BACTERIA
– PENICILLIN
– LYSOZYME

THE CELL MEMBRANE
• SIMILAR TO THAT OF EUCARYOTES
• 50% PROTEIN AND 50% LIPID IN CHEMICAL
COMPOSITION
• ACTIVE AND PASSIVE TRANSPORT
OBSERVED

• DIFFERENCES BETWEEN THE CELL
MEMBRANES OF THE EUCABTERIA AND
THE ARCHEOBACTERIA
– OVERLAPPING LIPID LAYERS
– DIFFERENT BONDING IN PHOSPHOLIPID
MOLECULES

CYTOPLASMIC CONTENTS
• RIBOSOMES
• STORAGE GRANULES
– CARBON RESERVE
• POLY-BETA-HYDROXYBUTYRATE
• GLYCOGEN
– VOLUTIN
– SULFUR
• ENDOSPORES

THE NUCLEAR APARATUS
• DNA
• SINGLE CIRCULAR MOLECULE OF
DOUBLE STRANDED DNA
• EXTRACHROMOSOMAL DNA - PLASMIDS

EXTERNAL STRUCTURES OF THE
BACTERIAL CELL
• FLAGELLA
– CHEMICAL COMPOSITION - PROTEIN
– ORGANELLE OF MOTILITY
– DIAMETER IS BELOW THE RESOLVING
POWER OF THE LIGHT MICROSCOPE
– ARRANGEMENT
• FIMBRIAE - ADHESION
• PILUS - CONJUGATION

A VARIETY OF CLINICALLY SIGNIFICANT
BACTERIA AND THE DISEASES THEY CAUSE
• RODS - ARRANGEMENT
–
ESCHERICHIA COLI
– CLOSTRIDIUM
–
CORYNEBACTERIUM
– MYCOBACTERIUM
–
LACTOBACILLUS
– BACILLUS

• COCCI - ARRANGEMENT
– DIPLOCOCCI
• NEISSERIA GONORRHOEAE
• NEISSERIA MENINGITIDIS
– STREPTOCOCCI
• STREPTOCOCCUS PYOGENES
•
STREPTOCOCCUS PNEUMONIAE
• ENTEROCOCCUS FAECIUM - VRE (VANCOMYCIN
RESISTANT ENTEROCOCCUS)
– TETRAD/SARCINAE MICROCOCCUS LUTEUS

– STAPHYLOCOCCI
• STAPHYLOCOCCUS AUREUS
•
STAPHYLOCOCCUS EPIDERMIDIS
• STAPHYLOCOCCUS SAPROPHYTICUS
• SPIRALS
– VIBRIO - CURVED RODS -
VIBRIO
CHOLERAE
– SPIROCHETES
•
TREPONEMA PALIDUM - SYPHILIS
• BORRELIA BURGDORFERI - LYME DISEASE

• A VARIETY OF CLINICALLY SIGNIFICANT
ATYPICAL BACTERIA
–
CHLAMYDIA
• OBLIGATE INTRACELLULAR PARASITES
• VERY SMALL - 1.5 X 0.2 MICROMETERS
• ENERGY PARASITES
• THREE CLINICALLY SIGNIFICANT EXAMPLES:
– CHLAMYDIA TRACHOMATIS
» STD
» EYE DISEASE SEEN OFTEN IN THIRD WORLD
COUNTRIES

– CHLAMYDIA PSITTACI - PSITTACOSIS
– CHLAMYDIA PNEUMONIAE
– RICKETTSIA
• OBLIGATE INTRACELLULAR
PARASITES
• VERY SMALL - 0.8 X 2.0
MICROMETERS
• TRAMSMITTED FROM HOST HOST BY
A VECTOR - INSECTS AND TICKS

– MYCOPLASMAS - IN THE FAMILY
MYCOPLASMATACEAE
• MYCOPLASMA PNEUMONIEA
•
MYCOPLASMA HOMINIS