Question

Medical Microbiology Tutorial: Bacterial Infections. Pseudomonas aeruginosa and Clostridium difficile

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Answer 1

note: I'm only grouping these two together because they're both bacteria that cause infections, and I don't have enough content to make two separate tutorials.

\({\bf{P. aeruginosa:}}\)


- is gram negative
- associated with cystic fibrosis esp in burn victims
- is an opportunist
- discovered in 1882 by Carle Gessard

Features:
- type I, II, and III secretions
- secretes exopolysaccharides (important in biofilm formation)
- secretes toxins and other secondary metabolites/signal molecules

has two different strategies, one associated w/ acute infections (growing and spreading rapidly) and the other w/ chronic infections (biofilm formation)

Symptoms: vary depending on what part of the body is infected
> bloodstream:
- fever, chills
- general aching
- low BP
- nausea/vomiting
- diarrhea

> lungs:
- pneumonia symptoms: fever, chills, breathing problems

> ear
- hearing problems
- localized pain
- swelling or discharge

> eyes
- vision problems
- general redness
- inflammation

Treatments:
- antibiotics given as pills, creams, drops, or in extreme cases, IV
- examples: tobramycin, meropenem or ceftazidime, colistin

Answer 2

\({\bf{C. difficile:}}\)


- gram positive
- obligate aerobe
- 1935: first isolated by Hall and O’Toole
- 1978: first linked to human disease by George (...RH were his other initials I think? for some reason I can't get a good reference for this)
- most frequently identified infectious agent in HA diarrhea cases

Transmission: by spores secreted in the vegetative state

Symptoms: often induced *by* antibiotics
- diarrhea
- pseudomembranous colitis: inflammation of colon
- general cramping
- fever/chills

Diagnosis:
- cytotoxin assays
- enzyme immunoassay
- stool samples
- PCR

Treatments:
- antibiotics such as metronidazole and vancomycin
- fecal transplants (yuck)

Answer 3

Sources:
- https://www.everydayhealth.com/pseudomonas-aeruginosa/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2935936/
- file:///C:/Users/Olivia/Downloads/linkage-isomers-protocol%20(2).pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2772362/
- https://jb.asm.org/content/188/4/1211
- https://medlineplus.gov/ency/article/000259.htm#targetText=Pseudomembranous%20colitis%20refers%20to%20swelling,of%20diarrhea%20after%20antibiotic%20use.
- https://www.cdc.gov/cdiff/what-is.html
- lecture notes