An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends beyond the swelling. Carbuncles and boils are types of abscess that often involve hair follicles, with carbuncles being larger. A cyst is related to an abscess, but it contains a material other than pus, and a cyst has a clearly defined wall.
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 for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although S. aureus usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. S. aureus is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant S. aureus (MRSA), is a worldwide problem in clinical medicine. Despite much research and development, no vaccine for S. aureus has been approved.
Methicillin-resistant Staphylococcus aureus (MRSA) is a group of gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans. It caused more than 100,000 deaths worldwide attributable to antimicrobial resistance in 2019.
Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of the area of redness are generally not sharp and the skin may be swollen. While the redness often turns white when pressure is applied, this is not always the case. The area of infection is usually painful. Lymphatic vessels may occasionally be involved, and the person may have a fever and feel tired.
A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils are therefore basically pus-filled nodules. Individual boils clustered together are called carbuncles. Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.
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 microbiota and also found in marine sponges. It is a facultative anaerobic bacteria. Although S. epidermidis is not usually pathogenic, patients with compromised immune systems are at risk of developing infection. These infections are generally hospital-acquired. S. epidermidis is a particular concern for people with catheters or other surgical implants because it is known to form biofilms that grow on these devices. Being part of the normal skin microbiota, S. epidermidis is a frequent contaminant of specimens sent to the diagnostic laboratory.
Flucloxacillin, also known as floxacillin, is an antibiotic used to treat skin infections, external ear infections, infections of leg ulcers, diabetic foot infections, and infection of bone. It may be used together with other medications to treat pneumonia, and endocarditis. It may also be used prior to surgery to prevent Staphylococcus infections. It is not effective against methicillin-resistant Staphylococcus aureus (MRSA). It is taken by mouth or given by injection into a vein or muscle.
Dicloxacillin is a narrow-spectrum β-lactam antibiotic of the penicillin class. It is used to treat infections caused by susceptible (non-resistant) Gram-positive bacteria. It is active against beta-lactamase-producing organisms such as Staphylococcus aureus, which would otherwise be resistant to most penicillins. Dicloxacillin is available under a variety of trade names including Diclocil (BMS).
Orbital cellulitis is inflammation of eye tissues behind the orbital septum. It is most commonly caused by an acute spread of infection into the eye socket from either the adjacent sinuses or through the blood. It may also occur after trauma. When it affects the rear of the eye, it is known as retro-orbital cellulitis.
Panton–Valentine leukocidin (PVL) is a cytotoxin—one of the β-pore-forming toxins. The presence of PVL is associated with increased virulence of certain strains (isolates) of Staphylococcus aureus. It is present in the majority of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates studied and is the cause of necrotic lesions involving the skin or mucosa, including necrotic hemorrhagic pneumonia. PVL creates pores in the membranes of infected cells. PVL is produced from the genetic material of a bacteriophage that infects Staphylococcus aureus, making it more virulent.
Lysostaphin is a Staphylococcus simulans metalloendopeptidase. It can function as a bacteriocin (antimicrobial) against Staphylococcus aureus.
mecA is a gene found in bacterial cells which allows them to be resistant to antibiotics such as methicillin, penicillin and other penicillin-like antibiotics.
Bullous impetigo is a bacterial skin infection caused by Staphylococcus aureus that results in the formation of large blisters called bullae, usually in areas with skin folds like the armpit, groin, between the fingers or toes, beneath the breast, and between the buttocks. It accounts for 30% of cases of impetigo, the other 70% being non-bullous impetigo.
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 anaerobic organisms.
Sophoraflavanone G is a volatile phytoncide, released into the atmosphere, soil and ground water, by members of the Sophora genus. Sophora pachycarpa, and Sophora exigua; all found to grow within the United States in a variety of soil types, within temperate conditions, no lower than 0 °F. Sophoraflavanone G is released in order to protect the plant against harmful protozoa, bacteria, and fungi. Sophoraflavanone G, also called kushenin, is a flavonoid compound.
Staphylococcus delphini is a Gram-positive, coagulase-positive member of the bacterial genus Staphylococcus consisting of single, paired, and clustered cocci. Strains of this species were originally isolated from aquarium-raised dolphins suffering from skin lesions.
Staphylococcus hyicus is a Gram-positive, facultatively anaerobic bacterium in the genus Staphylococcus. It consists of clustered cocci and forms white circular colonies when grown on blood agar. S. hyicus is a known animal pathogen. It causes disease in poultry, cattle, horses, and pigs. Most notably, it is the agent that causes porcine exudative epidermitis, also known as greasy pig disease, in piglets. S. hyicus is generally considered to not be zoonotic, however it has been shown to be able to cause bacteremia and sepsis in humans.
Staphylococcus schleiferi is a Gram-positive, cocci-shaped bacterium of the family Staphylococcaceae. It is facultatively anaerobic, coagulase-variable, and can be readily cultured on blood agar where the bacterium tends to form opaque, non-pigmented colonies and beta (β) hemolysis. There exists two subspecies under the species S. schleiferi: Staphylococcus schleiferi subsp. schleiferi and Staphylococcus schleiferi subsp. coagulans.
Staphylococcus pseudintermedius is a gram positive coccus bacteria of the genus Staphylococcus found worldwide. It is primarily a pathogen for domestic animals, but has been known to affect humans as well. S. pseudintermedius is an opportunistic pathogen that secretes immune modulating virulence factors, has many adhesion factors, and the potential to create biofilms, all of which help to determine the pathogenicity of the bacterium. Diagnoses of Staphylococcus pseudintermedius have traditionally been made using cytology, plating, and biochemical tests. More recently, molecular technologies like MALDI-TOF, DNA hybridization and PCR have become preferred over biochemical tests for their more rapid and accurate identifications. This includes the identification and diagnosis of antibiotic resistant strains.
MRSA ST398 is a specific strain of Methicillin-resistant Staphylococcus aureus (MRSA). Staphylococcus aureus is a gram-positive, spherical bacterium that can cause a range of infections in humans and animals. And Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that is resistant to many antibiotics. The abbreviation "ST" in MRSA ST398 refers to the sequence type of the bacterium. MRSA ST398 is a clonal complex 398 (CC398). This means that the strain had emerged in a human clinic, without any obvious or understandable causes. MRSA ST398, a specific strain of MRSA, is commonly found in livestock, and can cause infections in humans who come into contact with infected animals.
