Staphylococcal infection

Staphylococcal infection
SEM micrograph of S. aureus colonies; note the grape-like clustering common to Staphylococcus species.
Classification and external resources
MeSH	D013203

Staphylococci are species of Gram-positive bacteria that can cause a wide variety of infections in humans and other animals through infection or the production of toxins. Staphylococcal toxins are a common cause of food poisoning, as they can be produced in improperly-stored food. Staphylococci are also known to be a cause of bacterial conjunctivitis.^[1] Among neurosurgical patients, it can cause community-acquired meningitis.^[2]

Coagulase-positive

The main coagulase-positive staphylococcus is Staphylococcus aureus, although not all strains of Staphylococcus aureus are coagulase positive. These bacteria can survive on dry surfaces, increasing the chance of transmission. S. aureus is also implicated^[3] in toxic shock syndrome; during the 1980s some tampons allowed the rapid growth of S. aureus, which released toxins that were absorbed into the bloodstream. Any S. aureus infection can cause the staphylococcal scalded skin syndrome, a cutaneous reaction to exotoxin absorbed into the bloodstream. It can also cause a type of septicaemia called pyaemia. The infection can be life-threatening. Problematically, Methicillin-resistant Staphylococcus aureus (MRSA) has become a major cause of hospital-acquired infections, and is being, MRSA has also been recognized with increasing frequency in community-acquired infections.^[4] The symptoms of a Staph Infection include a collection of pus, such as a boil or furuncle, or abscess. The area is typically tender or painful and may be reddened or swollen.^[5]

Etymology

The generic name Staphylococcus is derived from the Greek word "staphyle" meaning a bunch of grapes, and "kokkos" means granule. The bacteria, when seen under a microscope appear like a branch of grapes or berries.

Other infections include:

• Closed-space infections of the fingertips, known as paronychia.

Coagulase-negative

• S. epidermidis, a coagulase-negative staphylococcus species, is a commensal of the skin, but can cause severe infections in immune-suppressed patients and those with central venous catheters.

• S. saprophyticus, another coagul^[7]ase-negative species that is part of the normal vaginal flora, is predominantly implicated in genitourinary tract infections in sexually-active young women.

• In recent years, several other staphylococcal species have been implicated in human infections, notably S. lugdunensis, S. schleiferi, and S. caprae.

References