Dataset: Antibiotics

Overview
These data are about the minimum inhibitory concentration (MIC) of three antibiotics for various bacteria.

Observations

 * Effect of Gram:
 * – Data fall under the  threshold more often.
 * – Neomycin excels here, as few other antibiotics are effective in this regime.

Team Delta
- Neomycin appears to be effective by MIC against more bacteria than penicillin or streptomycin

- Penicillin has some very high outlying MIC values.

- Certain bacteria (Staphylococcus aureus, Staphylococcus albus, Bacillus anthracis) can be treated by any of the 3 antibiotics effectively

- Certain bacteria do not appear to be human-treatable by any of the 3 antibiotics (Pseudomonas aeruginosa, Mycobacterium tuberculosis, Klebsiella pneumoniae, Aerobacter aerogenes)

- Gram relates to the thickness of the membrane layer of the bacteria that can be attached to. Penicillin seems to show a correlation of MIC value about 1.0 and above for bacteria with negative gram, and mostly below 0.1 for positive gram. There does not appear to be much correlation between gram and MIC for the other antibiotics. [ref]

The three antibiotics are much more effective against the gram-positive bacteria in this dataset
These antibiotics are more effective against the gram-positive bacteria in this dataset; and only neomycin is effective for use in humans against more than one of these gram-positive bacteria, while streptomycin can only effectively combat one of them in humans, and penicillin cannot effectively combat any of them in humans.

Gram positive bacteria have evolved defenses other than a cell wall that make them drug-resistant
Gram negative bacterial strains in this dataset are more drug-resistant than Gram positive bacterial strains. Gram positive bacteria strains have a physical defensive layer (think peptidoglycan cell wall) against antibiotics that can be pierced by penicillin. Meanwhile, the Gram negative bacterial strains have developed/possess other defenses against antibiotics (efflux pumps, mutation, and lactamase production).


 * Penicillin is effective for treating humans (MIC < 0.1 mug/ml) against the represented strains of Streptococcus, Staphylococcus, Diplococcus, and Bacillus.
 * Neomycin is effective for treating humans (MIS < 0.1 mug/ml) against Staphylococcus, Salmonella, Escherichia, Bucella, and acillus.
 * Streptomycin is effective for treating humans (MIS < 0.1 mug/ml) against Staphylococcus, Proteus, and Bacillus.
 * None of the antibiotics are effective for treating Pseudomonas, Mycobacterium, Klebsiella, or Aerobacter. Of note, all of these strains are gram positive.

For more than half the bacteria, the three antibiotics are not effective at a practical dosage
When looking at the MIC distribution across all bacteria (by antibiotic) and zooming into the sub-0.1 region, only neomycin has a median MIC (0.100)  within what’s considered a practical dosage. Zooming out, this is further confirmed by a point-plot where, visually, we can see a larger number of points above the 0.1 threshold for penicillin (10) and streptomycin (12).

An antibiotic’s effectiveness against one strain of a bacterium does not guarantee its effectiveness against another strain
Aside from some clustering of bacteria under the Streptococcus genus (noting that there are only two data points, which isn’t a large sample size), the other genuses do not seem to cluster.