Staph is short for Staphylococcus aureus, a strain of bacteria that can cause serious infections. Staphylococcus aureus can actually be found on the skin of most people where it grows without causing disease. However, when staph bacteria get past the skin, they can cause painful infections; several antibiotics are used to treat staph infections.
Beta-lactams
Penicillin, which is the original beta-lactam antibiotic, is the oldest treatment for staph infections. The term "beta-lactam" describes the chemical structure of these types of antibiotics, which attack staph bacteria by trying to destroy the bacterial cell wall. Often, however, staph bacteria are resistant to beta-lactam drugs; MayoClinic.com notes that less than 10 percent of all strains of Staphylococcus aureus are susceptible to penicillin. This is because many strains of staph have acquired a protein known as beta-lactamase, which destroys beta-lactam antibiotics. These drugs may still be effective, however, if combined with a medication that guards against these beta-lactamases, such as clavulanate or tazobactam, PodiatryToday explains.
Lactamase Resistant Antibiotics
Because most cases of Staphylococcus aureus involve strains with beta-lactamase, many cases of staph are treated with a class of bacteria known as lactamase resistant or beta-lactamase stable antibiotics. These include the antibiotics methicillin, dicloxacillin, nafcillin and oxacillin, PodiatryToday reports. However, many strains of staph have also developed resistance to this class of antibiotics, resulting in the development of Methicillin-resistant Staphylococcus aureus strains, also known as MRSA. Bacteria that are resistant to methicillin are typically resistant to the other antibiotics in this class, which can make treatment difficult. Determining to which antibiotics a staph infection is still susceptible is an important part of the treatment process. In order to determine if the patient has been infected with MRSA, a sample of the bacteria from the wound, urine or blood is sent to a lab, which will grow the bacteria and determine its sensitivity to an array of antibiotics, the University of Michigan website explains.
Antibiotics for MRSA
If a patient is infected with MRSA, there are a number of antibiotics which can be tried, the University of Maryland Medical Center website notes. Clindamycin, tetracycline, minocycline, linezolid, trimethoprim-sulfamethoxazole, doxycycline, daptomycin and vancomycin may all be used to treat strains of Staphylococcus aureus infections that are resistant to beta-lactams and the methicillin family of antibiotics. Vancomycin is sometimes administered before the results of the antibiotic sensitivity test are in because most strains of staph are susceptible to it.
