Classification of BacteriaClassification of BacteriaSurvey of Clinically Relevant Bacteria

Modern Prokaryotic ClassificationModern Prokaryotic Classification

Eubacteria

Archeabacteria

Cyanobacteria

Thermophiles

We will not forget the ArchaeaWe will not forget the ArchaeaHave no cell nucleus or any other membrane organelles within their cells.

In the past they were viewed as an unusual group of bacteria and named archaebacteria but since the

Archaea have an independent evolutionary history and show many differences in their biochemistry from other forms of life.

They are now classified as a separate domain

Diversity of BacteriaDiversity of Bacteria

Classification of BacteriaClassification of Bacteria Classification – ordering

Nomenclature – naming Often immortalizes the person

who discovered it or its origin◦ Escherichia coli Theodor

Escherich◦ coli from colon

Distinguishing –identification

Classification of BacteriaClassification of Bacteria *Kingdom Phylum Class Order Family *Genus ( 1st name) *Species ( 2nd name identifier)

Remember: King Philip Came Over For Good Spaghetti

Classification of BacteriaClassification of Bacteria

Morphology – shape, color, gram specificity

Metabolism

Molecular techniques – Forensics, DNA finger prints, RNA, protein analysis

1 Gram Negative Spiral Bacteria1 Gram Negative Spiral Bacteria Slender and flexible, come in a

lot of different shapes

More rigid than spirochetes

Ex. – Campylobacter jejuni

◦ Symptom – tenesmus: the sensation of desire to defecate, which is common and occurs frequently , with out the production of significant amounts of feces (often small amounts of mucous or blood are alone passed).

 

2 Gram Negative Spirochetes2 Gram Negative Spirochetes

pathogenic very flexible tightly coiled, helically coiled

Example ◦ syphilis

Treponema pallidum

Gram Negative SpirochetesGram Negative Spirochetes

Most of pathogenic Very flexible Tightly coiled, helically coiled

Example◦ Lyme disease

Borrelia burgdorferi(organism gets lodged in tissues)

3 Gram Negative Aerobic Rods3 Gram Negative Aerobic Rods

◦ Legionella pneumophila Lower respiratory tract

infection Needs oxygen

Gram Negative Aerobic RodsGram Negative Aerobic Rods

Bordetella pertussis – whooping cough Needs oxygen

Gram Negative Aerobic RodsGram Negative Aerobic Rods

◦ Pseudomonas aeruginosa (pigmented) Needs moisture Common in hospitals Opportunistic pathogen –

causes UTI, skin, and lung infection

Vibrio◦ V. cholerae

Most well known of group Very severe dysentery. Can lose

10-15 liters of water/day. Leads to hypovolemia – low water, hardly any water in body

◦ V. vulnificus Very pathogenic Can cause flesh eating disease,

if it gets in a wound

◦ V. parahaemolyticus Found in shellfish – oysters Halophile – loves salt (will find in oceans, estuaries) Self limiting

4 Gram Negative Facultative Rods4 Gram Negative Facultative Rods

Gram Negative Facultative RodsGram Negative Facultative Rods Enteric

◦ Salmonella◦ Shigella◦ E. coli (0157H7)

5 Gram Negative Anaerobic Rods5 Gram Negative Anaerobic Rods

Fusobacterium ◦ Live in between teeth

and gums

◦ Cause tooth abscesses and periodontal disease

◦ Teeth have nothing to anchor – bone is destroyed

 

6 Gram Negative Cocci or Coccobaccilli 6 Gram Negative Cocci or Coccobaccilli (plump rods)(plump rods)

Neisseria gonorrhoeae –

Usually a diplococcus inPMN

Sexually TransmittedDisease

very antibiotic resistant

Gram Negative Cocci or Coccobaccilli Gram Negative Cocci or Coccobaccilli (plump rods)(plump rods)

Neisseria meningitidisvery infectious and communicable.

Gram Negative Cocci or Coccobaccilli Gram Negative Cocci or Coccobaccilli (plump rods)(plump rods)Acinetobacter baumanni iv.lwoffi

opportunistic, UTI, skin,and upper respiratory

7 7 Chlamydia Chlamydia Gram Negative Rods Gram Negative Rods (Transitional)(Transitional)

Very short little rods Gram negative Transitional – doesn’t hold stain

well Do not have the ability to

synthesize own ATP, therefore and obligate intracellular parasite of other animals (humans)

Can go asymptomatic for a long time

Ex.◦ C. trachomatis – STD, causes

eye infection◦ C. psittaci – parrot (associated

with birds)

8 8 Rickettsia Gram Negative Rod Rickettsia Gram Negative Rod (Transitional)(Transitional)

Small gram negative rods

Transitional – doesn’t hold stain well

Can’t synthesize it’s own NAD, coenzyme A, therefore an obligate intracellular parasite

Causative agent of Rocky Mountain Spotted Fever

Example◦ R. Prowazekii

9 Mycoplasma 9 Mycoplasma Gram Positive Gram Positive (Transitional )(Transitional ) Gram positive – only because

they take in dye in cell membrane but it washes away

Transitional – doesn’t hold stain well.

Have no cell wall Can not treat with penicillin Ex.

◦ Mycoplasma pneumoniae – causes LRTI

◦ Ureaplasma urealyticum – causes UTI

◦ Both imbed themselves in the tissue. The most cell damage is done by the immune system destroying the tissue.

10 Gram Positive Cocci10 Gram Positive Cocci

Staphyloccocus aureusMRSA

These bacteria can break down all tissues of body.

Gram Positive CocciGram Positive Cocci

Streptococcus pyogenes – no antibiotic resistance right now

These bacteria can break down all tissues of body.

11 Gram positive Endospore Forming 11 Gram positive Endospore Forming RodsRods Difficult to get rid of

because of endospores

Example◦ Clostridium tetani

Gram positive Endospore Forming RodsGram positive Endospore Forming Rods

Difficult to get rid of because of endospores

Example C. perfringens – gangrene

Gram positive Endospore Forming RodsGram positive Endospore Forming Rods

Difficult to get rid of because of endospores

Common in hospitals Example

C. difficile

antibiotic associatedpseudmembraneousenterocolitis

Clostridium difficile Clostridium difficile

Gram positive Endospore Forming RodsGram positive Endospore Forming Rods

Bacillus B. anthracis – anthrax zoonosis

Gram positive Endospore Forming RodsGram positive Endospore Forming Rods

Bacillus B. cereus – food poising

Especially in high carb foods – rice, vermicelli

B. thuringiensis – natures insecticide

12 Coryneforms12 Coryneforms

Pleomorphic (many shapes) Example

Corynebacterium diphtheriae

1313 Mycobacteria Mycobacteria

Gram positive and Acid Fast

Mycobacterium tuberculosis

Respiratory Pathogen

MDR-TB

In the 1950s we sent people with TB to the sanitariums

Mycobacteria Mycobacteria

Gram positive and Acid Fast ◦ M. avium intracellular complex

(MAC) Really bad bug Currently no drugs can cure it Especially bad for people with

AIDS Can cause atypical TB

Mycobacteria Mycobacteria

Gram positive and Acid Fast

◦ M. leprae Causative agent of

leprosy Not very common Only affects areas of

body that are below body temperature

Natural reservoir is the armadillo