Staphylococcal infection

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

Staphylococci are a 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. Staphylococcus aureus can cause a number of different skin diseases. Among neurosurgical patients, it can cause community-acquired meningitis.

Types

Main Staphylococcus aureus infections
Type	Examples
Localized skin infections	Stye' and other small, superficial abscesses in sweat or sebaceous glands Subcutaneous abscesses (boils) around foreign bodies Large, deep infections (carbuncles) possibly causing bacteremia Folliculitis; an infection of a hair follicle Ear infections
Diffuse skin infection	Impetigo
Deep, localized infections	Acute and chronic osteomyelitis Septic arthritis
Other infections	Asthma and rhinitis Acute and chronic sinusitis Acute infective endocarditis Septicemia Necrotizing pneumonia
Toxinoses	Toxic shock syndrome Gastroenteritis Scalded skin syndrome
Unless else specified in boxes, then reference is

Other infections include:

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

Coagulase-positive

Further information: Staphylococcus aureus § Role in disease

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 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. 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.

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 coagulase-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.

Etymology

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