Doxycycline won’t work against methicillin-resistant Staphylococcus aureus (MRSA) infections. MRSA bacteria possess a modified protein that prevents doxycycline from binding and killing them.
Similarly, doxycycline struggles with Staphylococcus epidermidis infections, a common cause of device-related infections. These bacteria often exhibit resistance mechanisms that hinder doxycycline’s action.
Severe staph infections, especially those involving deep tissues or bloodstream, may not respond well to doxycycline. Stronger antibiotics are typically required to combat these severe cases.
Certain staph strains naturally possess resistance to tetracyclines, the family of antibiotics to which doxycycline belongs. This inherent resistance renders doxycycline useless against these strains.
Finally, incorrect dosage or incomplete treatment courses allow surviving bacteria to develop resistance. This makes doxycycline ineffective against future infections from the same strain.
