Microbiology Part 1 - First Aid Notes

Use an O2 dependent system to generate ATP
"Nagging Pests Must Breathe"

Nocardia, Pseudomonas Aeruginosa, Mycobacterium Tb, Bacillus Anthracis

"Anaerobes Can't Breath Air"
Clostridium, Bacteriodes, Actinomyces
Lack catalase and superoxide dismutase, thus are susceptible to oxidative damage within cell. (*remember superoxide dismutase SOD1 gene found in ALS too!)
Found in GI tract normally, pathologic elsewhere
Difficult to culture, foul-smelling, and gas producing bacteria
AminoglycOsides are ineffective because these Abs require O2 to get into bacterial cell wall

Some bugs go inside when it's Really Cold

Rickettsia, Chylamdia

"Some Nasty Bugs May Live Facultatively"

Salmonella, Neisseria, Brucella, Mycoplasma, Legionella, Francisella, Listeria, Yersinia

Capsules help prevent against phagocytosis
Quelling reaction - encapsulated bacteria cells will swell
If you don't have spleen, you need vaccines against encapsulated organisms (Sickle Cell Anemia, HSpherocytosis, etc)
Strep pneumonia, Niesseria meningitides, Haemophilus Influenza Type B, Klebseilla pneumoniae
Capsule helps serve as antigen in vaccinations

Urease is a protein found in microorganisms that help bacteria break down urea --> CO2 and NH3; enyzme that catabolizes the hydrolysis of urea
Found in UTIs to breakdown urea

"Ur Pee Kills Humans"
H. Pylori (urease breathe test), Proteus, Klebsiella, Ureaplasma

Part of the structure of gram negative bacteria itself (along with gram-positive Listeria) - outer cell membrane of Lipopolysaccharide
Toxicity is low, but becomes fatal with high orders of micrograms
No toxoids are created, so no vaccinations are available
Causes inflammation via TNF and IL-1 induced by Lipid A
Causes meningococcemia and sepsis by gram-negative rods

Substance released by gram-negative or gram-postiive bacteria
Toxicity is high with lower amounts of micrograms
Induces high-titer antibodies called anti-toxins
Toxoids can be used as vaccinations
Causes tetanus, botulism, and diphtheria

Ab resistance is commonly transferred
F+ x F- plasmid containing genes are transferred
Plasmid DNA only; no bacterial genes transferred

A bacteriophage infects a bacterium
Parts of bacterial DNA are lysed and and packaged together into viral capsid . The phage infects another bacterium and transfers those genes; transfers one bacterial DNA to another

These bacteria only begin to synthesize toxins when the DNA from bacteriophages get incorporated into the bacterial host genome via the lysogenic cycle

"ABCDE"
Shiga-like toxin, Botulinum toxin, Cholera toxin, Diphtheria toxin (beta prophage), and Erythrogenic toxin of S. pyogenes

Catalase +, Coagulase +
Protein A (virulence factor) binds Fc-IgG inhibiting complement fixation and phagocytosis
Causes inflammatory disease, Toxin-mediated disease (toxic shock syndrome TSST-1 toxin), Scalded skin syndrome (exfoliatin toxin), and rapid-onset food poisoning (enterotoxins)
MRSA - Resistance to B-lactams due to altered penicillin binding protein
Causes acute bacterial endocarditis, osteomyelitis, folliculitis and impetigo (honey-crusted lesions)

Toxic Shock Syndrome Exotoxin
Toxin released from Staph Aureus
Superantigen released that binds to MHCII T cell receptors lead to T-cell activation (keeping tampon in for too long causes TSS)

Due to release of exfoliatin toxin from Staph Aureus

Catalase +, Coagulase -, Novobiocin Sensitive
component of normal skin flora
infects prosthetic devices and catheters --> endocarditis
Glycocalyx on the cell surface allows binding of Staph epidermidis to foreign surfaces (ie catheters)