BACTERIA

• UBIQUITOUS IN NATURE• UNICELLULAR• LIGHT MICROSCOPIC - 0.2 - 2

MICROMETERS IN DIAMETER; 2 - 8 MICROMETERS IN LENGTH

• PROCARYOTIC IN CELL STRUCTURE• CELL SHAPE AND ARRANGEMENT

ANATOMY OF A TYPICAL BACTERIUM

• THE GLYCOCALYX – A SUGAR COAT

• CAPSULE, SLIME LAYER, BIOFILM

– PRODUCED WITHIN THE CELL AND SECRETED EXTRACELLULARLY

• CAPSULE

• CARBOHYDRATE - POLYSACCHARIDE

• WELL ORGANIZED

• LAYED DOWN EVENLY AROUND THE CELL WALL

• FIRMLY ATTACHED

• NOT EASILY PENETRATED

ADVANTAGES OF HAVING A CAPSULE

• ADHERENCE

• NUTRITION SOURCE• PROTECTION

– ANTIBIOTICS– IMMUNE SYSTEM– NUTRIENT AND WATER LOSS

SLIME LAYER

• NOT WELL ORGANIZED• EASILY PENETRATED• ADVANTAGES OF A SLIME LAYER

BIOLFILM

• BACTERIA LIVE IN COMMUNITIES CALLED BIOFILMS

• USUALLY ATTACHED TO SOMETHING – CATHETER, HEART VALVE, TOOTH, MUCOUS MEMBRANE

• ADVANTAGES OF A BIOFILM:

• PROTECTION FROM: DESSICATION, ANTIBIOTICS, BODY’S IMMUNE SYSTEM

• 70% OF HUMAN BACTERIAL INFECTIONS INVOLVE BIOLFILMS

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

THE GRAM POSITIVE CELL WALL

• SINGLE LAYER• UP TO 90% PEPTIDOGLYCAN• 15-20 nm THICK• CONTAIN TEICHOLIC ACIDS WHICH ARE

ACIDIC POLYSACCHARIDES• CONTROL AUTOLYSINS IN THE CELL

THE GRAM NEGATIVE CELL WALL

• SEVERAL LAYERS SEEN• 10-15 nm THICK

• INTERESTING CHARACTERISTICS OF THE AMINO ACIDS IN PEPTIDOGLYCAN

• AMINO ACIDS CAN TAKE ON TWO STRUCTURAL CONFIRMATIONS IN SPACE

• D-AMINO ACIDS VS L-AMINO ACIDS

• DIAMINOPIMELIC ACID – AA FOUND ONLY IN PEPTIDOGLYCAN

• INTERESTING CHEMICALS THAT EFFECT THE CELL WALL OF BACTERIA.

• PENICILLIN• LYSOZYME

• DIFFERENCES BETWEEN THE CELL WALLS

OF THE ARCHAEABACTERIA AND THE EUBACTERIA.

• ARCHAEABACTERIA HAVE NO

PEPTIDOGLYCAN IN THEIR CELL WALLS• THERE ARE NO D AMINO ACID ISOMERS IN

THE CELL WALL OF THE ARCHAEABACTERIA. ONLY L AMINO ACID ISOMERS

• THE ARCHAEABACTERIA ARE GRAM VARIABLE

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 EUCBATERIA AND THE ARCHEOBACTERIA– OVERLAPPING LIPID LAYERS– DIFFERENT BONDING IN PHOSPHOLIPID

MOLECULES

CYTOPLASMIC CONTENTS

CYTOPLASMIC CONTENTS

• RIBOSOMES– MAKE UP MAJOR PART OF CYTOPLASM– 15,000+ PER CELL - POLYRIBOSOMES– 60% PROTEIN AND 40% RNA

• STORAGE GRANULES– CARBON RESERVE

• POLY-BETA-HYDROXYBUTYRATE• GLYCOGEN

– VOLUTIN– SULFUR

• ENDOSPORES

THE NUCLEAR APARATUS

• DNA• USUALLY A SINGLE CIRCULAR MOLECULE

OF DOUBLE STRANDED DNA• CAN BE LINEAR AS IN BORELLIA

BURGDORFERI

• EXTRACHROMOSOMAL DNA – PLASMIDS• DEFINITION OF A PLASMID• REPLICATES AUTONOMOUSLY• EASILY PASSED FROM BACTERIUM TO

BACTERIUM• PLASMID GENES ARE NOT NECESSARY

FOR THE SURVIVAL OF THE BACTERIUM• PLASMIDS USED IN GENETIC

ENGINEERING

EXTERNAL STRUCTURES OF THE BACTERIAL CELL

• FLAGELLA– CHEMICAL COMPOSITION - PROTEIN– ORGANELLE OF MOTILITY– DIAMETER IS BELOW THE RESOLVING

POWER OF THE LIGHT MICROSCOPE– ARRANGEMENT

• POLAR

• PERITRICHOUS

• FIMBRIAE - ADHESION

• PILUS - CONJUGATION

CLINICALLY SIGNIFICANT BACTERIA

A VARIETY OF CLINICALLY SIGNIFICANT BACTERIA AND THE DISEASES THEY CAUSE

• RODS - ARRANGEMENT– ESCHERICHIA COLI – STRAIN 0157:H7

• HUS-hemolytic – uremic - syndrome

– CLOSTRIDIUM– CORYNEBACTERIUM– MYCOBACTERIUM– LACTOBACILLUS– BACILLUS

• COCCI – ARRANGEMENT

• DIPLOCOCCI• NEISSERIA GONORRHOEAE – pp 790-792• NEISSERIA MENINGITIDIS – pp 645-646

• STREPTOCOCCI – pp 620-622;675-676; 714-715• STREPTOCOCCUS PYOGENES

– SCARLET FEVER– RHEUMATIC FEVER

• STREPTOCOCCUS PNEUMONIAE – pp 456;716• ENTEROCOCCUS FAECIUM - VRE (VANCOMYCIN RESISTANT

ENTEROCOCCUS) – pp 593– NOSOCOMIAL INFECTIONS

• TETRAD/SARCINAE - MICROCOCCUS LUTEUS

– STAPHYLOCOCCI• STAPHYLOCOCCUS AUREUS – pp 436;593;615-

20;675;751-2; MRSA, VISA, VRSA– NOSOCOMIAL INFECTIONS

• STAPHYLOCOCCUS EPIDERMIDIS

• STAPHYLOCOCCUS SAPROPHYTICUS

• SPIRALS• VIBRIO – CURVED RODS – VIBRIO

CHOLORAE – pp 755-758• SPIROCHETES

• TREPONEMA PALLIDUM – SYPHYLIS – pp 794-799

• BORRELIA BURGDORFERI – LYME DISEASE• pp. 685-687

BACTERIAL DIVERSITY• A VARIETY OF CLINICALLY SIGNIFICANT ATYPICAL

BACTERIA• CHLAMYDIAE – PHYLUM- pp 336-7;636;727;729;792-4• OBLIGATE INTRACELLULAR PARASITES• NO PEPTIDOGLYCAN IN THEIR CELL WALL• VERY SMALL RODS - 1.5 X 0.2 MICROMETERS• ENERGY PARASITES • TWO GENERA: CHLAMYDIA AND CHLAMYDOPHILA

• CHLAMYDIA TRACHOMATIS (STD)• EYE DISEASE SEEN OFTEN IN THIRD WORLD

COUNTRIES• CHLAMYDOPHILA PSITTACI – PSITTACOSIS• CHLAMYDOPHILA PNEUMONIAE

• RICKETTSIAE – PHYLUM -pp 316;687-688• OBLIGATE INTRACELLULAR PARASITES• VERY SMALL PLEOMORPHIC RODS – 0.8 X

2.0 MICROMETERS• TRANSMITTED FROM HOST TO HOST BY A

VECTOR – INSECTS AND TICKS• MOST PATIENTS PRESENT WITH A RASH• ROCKYMOUNTAIN SPOTTED FEVER

• MYCOPLASMAS – IN THE FAMILY MYCOPLASMATACEAE – pp 333-4; 726,794

• NO CELL WALL• FREE LIVING• VERY SMALL – SMALLEST FREE LIVING

ORGANISMS KNOWN• 0.3 – 0.5 MICROMETERS IN DIAMETER• CAN SLIP THROUGH 0.2 MICROMETER

MEMBERANE FILTERS• HAVE STEROLS IN THEIR CELL

MEMBRANES

• MYCOPLASMA PNEUMONIAE – WALKING OR ATYPICAL PNEUMONIA

• MYCOPLASMA HOMINIS - STD