Intact skin serves as an effective barrier to bacteria and fungi. A break in the skin, however, provides an entry site for infectious organisms, possibly leading to a wound infection. The seriousness of a wound infection depends on the type of organism involved, the cause and depth of the wound, the strength of the immune system and the presence of pre-existing conditions that may compromise wound healing.
Staphylococcal Infections
Staphylococcal bacteria commonly inhabit the skin surface, making these bacteria a frequent cause of wound infections when the skin barrier is breached, notes Kenneth Todar, Ph.D., in the electronic reference text "Todar’s Online Textbook of Bacteriology." Superficial skin wounds caused by scratches, cuts or abrasions typically heal without incident, despite local infection with staphylococcal or other normal skin bacteria.
Skin wounds that extend into the deep layers of the skin may lead to cellulitis, an infection of the base layers of the skin. Staphylococcal bacteria also commonly cause surgical and other hospital-acquired wound infections. In the hospital environment, methicillin-resistant Staphylococcus aureus, or MRSA, remains a significant concern. This variant of staphylococcal bacteria is resistant to the activity of several antibiotics, including methicillin, amoxicillin, penicillin and oxacillin, reports the Centers for Disease Control and Prevention. The antibiotic resistance expressed by these bacteria complicates the treatment of MRSA wound infections.
Sporotrichosis
Sporotrichosis is a fungal wound infection caused by Sporothrix schenckii. The fungus lives in mulch, and on hay, sphagnum moss, rose bushes and other plant matter, notes the Centers for Disease Control and Prevention. Minor cuts incurred while handling contaminated plants or soil may lead to infection. CDC notes that a delay of one to 12 weeks occurs between the time of the injury and the first symptoms of sporotrichosis. A small red to purple lump develops at the injury site. Additional lumps appear as the infection spreads to nearby lymph nodes. The lesions break open with time, causing persistent ulcers. In people with a weakened immune system, Sporothrix schenckii wound infections may spread to other parts of the body, including the kidneys, eyes, large joints and bones.
Vibrio Infections
The bacterium Vibrio vulnificus lives in warm salt water, including waters along the southern coastal areas of the United States. Skin wounds exposed to Vibrio vulnificus-contaminated water may become infected with the bacteria, potentially causing a life-threatening wound infection. In a 2007 review article published in "American Family Physician," Dr. Michael Bross and colleagues report that people with Vibrio vulnificus wound infections typically develop a rapidly advancing cellulitis with fever, chills and swelling of the affected area. In many patients, the infection spreads to the bloodstream. Bross and colleagues note that approximately 15 percent of people with Vibrio vulnificus wound infections die from complications of the illness.
References
- Todar’s Online Textbook of Bacteriology: Staphylococcus aureus and Staphylococcal Disease
- Centers for Disease Control and Prevention: Overview of Healthcare-associated MRSA
- Centers for Disease Control and Prevention: Sporotrichosis
- Merck Manual for Healthcare Professionals: Sporotrichosis
- “American Family Physician”; Vibrio Vulnificus Infection--Diagnosis and Treatment; Michael H. Bross, M.D., et al.; August 2007
