A staphylococcal infection or staph infection is an infection caused by members of the ''
Staphylococcus
''Staphylococcus'' is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultative ...
'' genus of bacteria.
These bacteria commonly inhabit the skin and nose where they are innocuous, but may enter the body through cuts or abrasions which may be nearly invisible. Once inside the body, the bacteria may spread to a number of body systems and organs, including the heart, where the toxins produced by the bacteria may cause
cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
. Once the bacterium has been identified as the cause of the illness, treatment is often in the form of
antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...
and, where possible, drainage of the infected area. However, many strains of this bacterium have become
antibiotic resistant
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...
; for those with these kinds of infection, the body's own
immune system
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...
is the only defense against the disease. If that system is weakened or compromised, the disease may progress rapidly. Anyone can contract staph, but pregnant women, children, and people with chronic diseases or who are immuno-deficient are often more susceptible to contracting an infection.
Types
Other infections include:
* Closed-space infections of the fingertips, known as
paronychia
Paronychia is an inflammation of the skin around the nail, which can occur suddenly, when it is usually due to the bacterium '' Staphylococcus aureus'', or gradually when it is commonly caused by the fungus ''Candida albicans''. The term is fr ...
.
* Suspected involvement in
atopic dermatitis
Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in puritis, itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thickens o ...
(eczema), including related clinical trials.
Coagulase-positive
The main
coagulase
Coagulase is a protein enzyme produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of '' Staphylococcus'' isolates. Importantly, '' S. aureus' ...
-positive staphylococcus is ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...
'', 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
Toxic shock syndrome (TSS) is a condition caused by bacterial toxins. Symptoms may include fever, rash, skin peeling, and low blood pressure. There may also be symptoms related to the specific underlying infection such as mastitis, osteomyeliti ...
; during the 1980s some
tampon
A tampon is a feminine hygiene, menstrual product designed to absorb blood and vaginal secretions by insertion into the vagina during menstruation. Unlike a Sanitary napkin, pad, it is placed internally, inside of the vaginal canal. Once inser ...
s 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
Staphylococcal scalded skin syndrome (SSSS) is a dermatological condition caused by ''Staphylococcus aureus''.
Signs and symptoms
The disease presents with the widespread formation of fluid-filled blisters that are thin walled and easily rupture ...
, a cutaneous reaction to
exotoxin
An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host. Exotoxins may be secreted, or, simi ...
absorbed into the bloodstream. It can also cause a type of
septicaemia
Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...
called
pyaemia
Pyaemia (or pyemia) is a type of sepsis that leads to widespread abscesses of a metastatic nature. It is usually caused by the staphylococcus bacteria by pus-forming organisms in the blood. Apart from the distinctive abscesses, pyaemia exhibit ...
. The infection can be life-threatening. Problematically,
methicillin-resistant ''Staphylococcus aureus'' (MRSA) has become a major cause of
hospital-acquired infections
A hospital-acquired infection, also known as a nosocomial infection (from the Greek , meaning "hospital"), is an infection that is acquired in a hospital or other health care facility. To emphasize both hospital and nonhospital settings, it is ...
. 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
''Staphylococcus epidermidis'' is a Gram-positive bacterium, and one of over 40 species belonging to the genus ''Staphylococcus''. It is part of the normal human microbiota, typically the skin microbiota, and less commonly the mucosal microbiot ...
'', a
coagulase
Coagulase is a protein enzyme produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of '' Staphylococcus'' isolates. Importantly, '' S. aureus' ...
-negative staphylococcus species, is a commensal of the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
, but can cause severe infections in
immune-suppressed patients and those with
central venous catheters
A central venous catheter (CVC), also known as a central line(c-line), central venous line, or central venous access catheter, is a catheter placed into a large vein. It is a form of venous access. Placement of larger catheters in more centra ...
.
* ''
S. saprophyticus'', another
coagulase
Coagulase is a protein enzyme produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of '' Staphylococcus'' isolates. Importantly, '' S. aureus' ...
-negative species that is part of the normal
vaginal flora
Vaginal flora, vaginal microbiota or vaginal microbiome are the microorganisms that colonize the vagina. They were discovered by the German gynecologist Albert Döderlein in 1892 and are part of the overall human flora.
The amount and type of ...
, is predominantly implicated in uncomplicated lower
genitourinary tract
The genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathw ...
infections in young sexually active women.
* Other staphylococcal species have been implicated in human infections, notably ''
S. lugdunensis'', ''
S. schleiferi'', and ''
S. caprae''.
Causes
Staph infections have a multitude of different causes, such as:
* Open wounds – This is by far the biggest cause of staph infection. Any open wound, even ones as small as a paper cut, are vulnerable to being infected. Staph bacteria will enter the body through any open wound, so it is important to properly treat, disinfect, and bandage any wounds.
* Contact with infected persons or surfaces – Staph infections are very contagious when in contact with a person that is already infected. A person with staph infection is contagious until the bacteria are completely out of their body, and any wounds from the infection are healed. It is common to see the spread of staph in contact sports; i.e. wrestling, through contact in locker rooms, or by sharing any equipment.
* Weakened immune system – Anyone with a weakened immune system for any reason can be more easily affected by staph bacteria, because their bodies are unable to defend against infectious bacteria as well.
* Unwashed linens – Staph bacteria are very resistant under harsh conditions, and they will cling to objects where they can create a niche. Unwashed bath towels, blanket, bed sheets, and clothes can create a great environment for these bacteria to grow. This is important to recognize, because every single day people use linens in their daily lives.
* Infection after surgery – Hospitals are a very common place for staph bacteria to contaminate. This becomes problematic when people are in surgery, because in some cases staph can be introduced to a person's body when an incision is opened.
* Invasive devices – Medical devices that have any connection to organs to the outside of the body are very problematic, because they allow an easy open pathway into the body. Examples of these devices are; catheters, dialysis tubing, feeding tubes, breathing tubes, etc.
Signs and symptoms
![Cellulitis Left Leg](https://upload.wikimedia.org/wikipedia/commons/5/5c/Cellulitis_Left_Leg.JPG)
Staph infection is typically characterized by redness, pus, swelling, and tenderness in areas of the infection. But, each type of skin infection caused by staph bacteria is different.
A few common skin infections caused by staph bacteria are:
* Boils – Boils are the most common type of staph infection, they are pockets of white pus that start where a hair follicle or oil gland is. The boil is tender and red where the infection is located on the skin.
* Impetigo – Impetigo is most prominent among children, and is usually located around their mouth, nose, hands, and feet. It shows up like a rash of painful blisters, will eventually produce pus that is yellowish in color.
* Cellulitis – Cellulitis is also rash-like; the skin that is infected will be red, swollen, and usually warm to the touch. Cellulitis commonly infects the lower legs, but can also, less commonly, affect the face and arms.
* Staphylococcus scalded skin syndrome – Staphylococcus scalded skin syndrome is caused by toxins produced when a staph infection gets too severe. It is characterized by a fever, rash, and blisters.
* Methicillin-resistant ''Staphylococcus aureus'' (MRSA) – MRSA is one of the most common antibiotic-resistant strains of staph bacteria. It is more difficult to treat than other staph infections. MRSA causes rashes, boils, sores, and other abscesses.
Treatment
Treatment for staph infection varies depending on the type and severity of infection. Common treatments are antibiotics, topical creams, and drainage/cleaning of infectious wounds.
Etymology
The generic name Staphylococcus is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
word "staphyle", meaning bunch of grapes, and "kokkos", meaning granule. The bacteria, when seen under a microscope, appear like a branch of grapes or nuts.
Epidemiology
Staphylococcus bacteria is one of the leading community-acquired bacteria. According to the CDC, after a push from hospitals to better prevent staph infections, the percentage of people affected has dropped dramatically. However, staph infections are still prominent and a cause for concern among healthcare professionals, especially new antibiotic-resistant strains. In the U.S., the incidence of staph infection is around 38.2 to 45.7 per 100,000 person-years, whereas other
First World
The concept of First World originated during the Cold War and comprised countries that were under the influence of the United States and the rest of NATO and opposed the Soviet Union and/or communism during the Cold War. Since the collapse of ...
countries have an average incidence rate of 10 to 30 per 100,000 person-years.
References
External links
{{Bacterial cutaneous infections
Staphylococcaceae
Bacterial toxins