Many types of bacteria can cause skin infections. Most cases are caused by Staphylococcus aureus "staph" or Streptococcus pyogenes "strep". Strep infections still respond well to standard antibiotics. However, that is not true for all staph infections. Over the last few decades, it has become more common for a certain strain of drug-resistant staph bacteria to cause skin infections. Originally, these resistant staph infections were seen mostly in hospitals.
MRSA Skin Infection
Staphylococcus aureus Infections - Infections - MSD Manual Consumer Version
Folliculitis and skin abscesses are pus-filled pockets in the skin resulting from bacterial infection. They may be superficial or deep, affecting just hair follicles or deeper structures within the skin. See also Overview of Bacterial Skin Infections. Folliculitis is a type of skin abscess that involves the hair follicle. Other types of abscesses may appear both on the skin surface and within the deeper structures of the skin without always involving a hair follicle.
Folliculitis and Skin Abscesses
Methicillin-resistant Staphylococcus aureus MRSA infection is caused by a type of staph bacteria that's become resistant to many of the antibiotics used to treat ordinary staph infections. Most MRSA infections occur in people who've been in hospitals or other health care settings, such as nursing homes and dialysis centers. HA-MRSA infections typically are associated with invasive procedures or devices, such as surgeries, intravenous tubing or artificial joints. Another type of MRSA infection has occurred in the wider community — among healthy people. It's spread by skin-to-skin contact.
Staphylococcus aureus is the most dangerous of all of the many common staphylococcal bacteria. These gram-positive , sphere-shaped coccal bacteria see figure How Bacteria Shape Up often cause skin infections but can cause pneumonia, heart valve infections, and bone infections. These bacteria are spread by having direct contact with an infected person, by using a contaminated object, or by inhaling infected droplets dispersed by sneezing or coughing.