Disinfection
This may or may not be what you had in mind, but the first line of defense is the skin, which keeps out pathogenic organisms. Then there is the immune system.
Developing new antibiotics that are effective against multi-drug resistant strains of pathogenic bacteria such as methicillin resistant Staph.
Patchouli oil was investigated for antimicrobial activity against a panel of ten human pathogenic bacteria and eight human pathogenic fungi. It showed a significant antimicrobial activity against all tested organisms compared to standard antibiotic Ampicillin. However, patchouli is more active against Gram positive than Gram negative bacteria.
Penicillin is NOT effective against gram positive and negative cocci and gram positive bacilli only. it is not effective against rest of the organisms.
penicillins
Free chlorine is effective against all pathogenic contaminants when added to water in high concentrations and provided a long enough contact time.However, at practical concentrations free chlorine is ineffective in dis-activating protozoa, particularly Cryptosporidium, Parvum oocysts and Giardia lamblia cysts.
kills any pathogenic bacteria in your body
Disinfectants are effective against vegetative cells and viruses, but not endospores.
Non-pathogenic bacteria are bacteria that don't cause diseases. The bacteria that ferment yogurt are non-pathogenic.
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Metronidazole is not effective against the step throat.
electric and ice are effective against flying