Classification of Bacteria Survey of Clinically Relevant Bacteria

Modern Prokaryotic Classification Eubacteria Archeabacteria Cyanobacteria Thermophiles

We will not forget the Archaea Have 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 Bacteria

Classification 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 Bacteria *Kingdom Phylum Class Order Family *Genus ( 1st name) *Species ( 2nd name identifier) Remember: King Philip Came Over For Good Spaghetti

Classification of Bacteria Morphology – shape, color, gram specificity Metabolism Molecular techniques – Forensics, DNA finger prints, RNA, protein analysis

1 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 Spirochetes pathogenic very flexible tightly coiled, helically coiled Example syphilis Treponema pallidum

Gram 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 Rods Legionella pneumophila Lower respiratory tract infection Needs oxygen

Gram Negative Aerobic Rods Bordetella pertussis – whooping cough Needs oxygen

Gram Negative Aerobic Rods Pseudomonas aeruginosa (pigmented) Needs moisture Common in hospitals Opportunistic pathogen – causes UTI, skin, and lung infection

4 Gram Negative Facultative Rods 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

Gram Negative Facultative Rods Enteric Salmonella Shigella E. coli (0157H7)

5 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 (plump rods) Neisseria gonorrhoeae – Usually a diplococcus in PMN Sexually Transmitted Disease very antibiotic resistant

Gram Negative Cocci or Coccobaccilli (plump rods) Neisseria meningitidis very infectious and communicable.

Gram Negative Cocci or Coccobaccilli (plump rods) Acinetobacter baumanni iv. lwoffi opportunistic, UTI, skin, and upper respiratory

7 Chlamydia Gram Negative Rods (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 Rickettsia Gram Negative Rod (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 Gram Positive (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 Cocci Staphyloccocus aureus MRSA These bacteria can break down all tissues of body.

Gram Positive Cocci Streptococcus pyogenes – no antibiotic resistance right now These bacteria can break down all tissues of body.

11 Gram positive Endospore Forming Rods Difficult to get rid of because of endospores Example Clostridium tetani

Gram positive Endospore Forming Rods Difficult to get rid of because of endospores Example C. perfringens – gangrene

Gram positive Endospore Forming Rods Difficult to get rid of because of endospores Common in hospitals Example C. difficile antibiotic associated pseudmembraneous enterocolitis

Clostridium difficile

Gram positive Endospore Forming Rods Bacillus B. anthracis – anthrax zoonosis

Gram positive Endospore Forming Rods Bacillus B. cereus – food poising Especially in high carb foods – rice, vermicelli B. thuringiensis – natures insecticide

12 Coryneforms Pleomorphic (many shapes) Example Corynebacterium diphtheriae

13 Mycobacteria Mycobacterium tuberculosis Gram positive and Acid Fast Respiratory Pathogen MDR-TB In the 1950s we sent people with TB to the sanitariums

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 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