Experiments examining the effects of antibiotics, antiseptics and disinfectants on bacterial growth
In this lab three types of inhibitors are used: antibiotics, antiseptics, and disinfectants. Antibiotics
are chemotherapeutic agents that prevent or destroy microbes (specifically bacteria, fungi, and
Antiseptics are applied to living tissue to kill microbes. Disinfectants are used to
destroy microorganisms on non-living surfaces. The antibiotics used in this lab were Oxacillin
(OX), Sulfamexathoxazole with Trimethroprim (SXT), Penicillin (P-2), Gentamicin (GM-10),
Cephalothin (CF-30), Erthromycin (E-15), Ciprofloxacin (CIP-5), and Novabiocin (NB-30).
antiseptics used were Rubbing Alcohol, Hydrogen Peroxide, Listerine, Baking Soda, and
The disinfectants used were Clorox, Lysol, Ammonia, and Vinegar.
negative control was used and it was Distilled Water.
The bacteria tested in the lab were
Escherichia coli (Sample 1), Pseudomonas aeruginosa (Sample 2), and Staphylococcus aurelius
I predict that all three bacteria will be susceptible to Ciprofloxacin. This is because it is a
commonly used, strong, and broad-spectrum antibiotic. I also predict that Gram negative and
positive bacteria will be affected by the antiseptics Alcohol, Hydrogen Peroxide, and
Bactericidal Soap. This are all commonly used to clean minor cuts so they should be effective
against both types of bacteria.
Lastly, I predict that the disinfectants Lysol and Bleach are very
effective against both types of bacteria. This is because both of these commercial products claim
in there advertisements that the kill 99.9% of bacteria.
Materials and Methods
See lab Manuel pages 137-161