In the herbal world, one would choose an antibiotic that is appropriate to the ailment.
Garlic is one of the best herbal antibiotics. It can help fight off a cold or the flu, and can be used in many ways
Goldenseal (Hydrastis) can be used, but only for short time frames. It can be used to wash cuts to help prevent infection.
Oregon Grape (Berberis aquifolium) contains berberine which is antibacterial. It helps stop bacteria from adhering to the intestine walls. Very useful for urinary tract infections.
Echinacea boosts the immune system, and will help the body to fight off infections. People with auto immune disorders should NOT take Echinacea.
Calendula is used both internally and externally for it's antibacterial and antibiotic qualities. Used for gut and stomach issues internally, and topically for skin.
Thyme, Oregano, Ginger and a couple others can also be used.