SepsisSepsis (septicaemia in British English), or blood poisoning, is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection.
ErysipelasErysipelas (ˌɛrəˈsɪpələs) is a relatively common bacterial infection of the superficial layer of the skin (upper dermis), extending to the superficial lymphatic vessels within the skin, characterized by a raised, well-defined, tender, bright red rash, typically on the face or legs, but which can occur anywhere on the skin. It is a form of cellulitis and is potentially serious. Erysipelas is usually caused by the bacteria Streptococcus pyogenes, also known as group A β-hemolytic streptococci, which enters the body through a break in the skin, such as a scratch or an insect bite.
Pathogenic bacteriaPathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
PusPus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during bacterial or fungal infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule, pimple or spot. Pus consists of a thin, protein-rich fluid (historically known as liquor puris) and dead leukocytes from the body's immune response (mostly neutrophils).
Pseudomonas aeruginosaPseudomonas aeruginosa is a common encapsulated, Gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, P. aeruginosa is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes.
CellulitisCellulitis 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.
BacteriaBacteria (bækˈtɪəriə; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere.
NeutrophilNeutrophils (also known as neutrocytes, heterophils or polymorphonuclear leukocytes) are a type of white blood cell. More specifically, they form the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in different animals. They are formed from stem cells in the bone marrow and differentiated into subpopulations of neutrophil-killers and neutrophil-cagers.
PathogenIn biology, a pathogen (πάθος, pathos "suffering", "passion" and -γενής, -genēs "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term pathogen came into use in the 1880s. Typically, the term pathogen is used to describe an infectious microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease.
ClindamycinClindamycin is an antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media (middle ear infections), and endocarditis. It can also be used to treat acne, and some cases of methicillin-resistant Staphylococcus aureus (MRSA). In combination with quinine, it can be used to treat malaria. It is available by mouth, by injection into a vein, and as a cream or a gel to be applied to the skin or in the vagina.
Streptococcal pharyngitisStreptococcal pharyngitis, also known as streptococcal sore throat (strep throat), is pharyngitis (an infection of the pharynx, the back of the throat) caused by Streptococcus pyogenes, a gram-positive, group A streptococcus. Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the front of the neck. A headache and nausea or vomiting may also occur. Some develop a sandpaper-like rash which is known as scarlet fever. Symptoms typically begin one to three days after exposure and last seven to ten days.
StreptococcusStreptococcus is a genus of gram-positive coccus (plural cocci) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells.
Innate immune systemThe innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an alternate defense strategy and is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms (see Beyond vertebrates).
PhagocytePhagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are essential for fighting infections and for subsequent immunity. Phagocytes are important throughout the animal kingdom and are highly developed within vertebrates. One litre of human blood contains about six billion phagocytes.
ImpetigoImpetigo is a bacterial infection that involves the superficial skin. The most common presentation is yellowish crusts on the face, arms, or legs. Less commonly there may be large blisters which affect the groin or armpits. The lesions may be painful or itchy. Fever is uncommon. It is typically due to either Staphylococcus aureus or Streptococcus pyogenes. Risk factors include attending day care, crowding, poor nutrition, diabetes mellitus, contact sports, and breaks in the skin such as from mosquito bites, eczema, scabies, or herpes.
Neisseria meningitidisNeisseria meningitidis, often referred to as the meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a coccus because it is round, and more specifically a diplococcus because of its tendency to form pairs. About 10% of adults are carriers of the bacteria in their nasopharynx. As an exclusively human pathogen, it is the main cause of bacterial meningitis in children and young adults, causing developmental impairment and death in about 10% of cases.
Necrotizing fasciitisNecrotizing fasciitis (NF), also known as flesh-eating disease, is a bacterial infection that results in the death of parts of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms usually include red or purple skin in the affected area, severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum. Typically, the infection enters the body through a break in the skin such as a cut or burn.
Rheumatic feverRheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful joints, involuntary muscle movements, and occasionally a characteristic non-itchy rash known as erythema marginatum. The heart is involved in about half of the cases. Damage to the heart valves, known as rheumatic heart disease (RHD), usually occurs after repeated attacks but can sometimes occur after one.
Acute proliferative glomerulonephritisAcute proliferative glomerulonephritis is a disorder of the small blood vessels of the kidney. It is a common complication of bacterial infections, typically skin infection by Streptococcus bacteria types 12, 4 and 1 (impetigo) but also after streptococcal pharyngitis, for which it is also known as postinfectious glomerulonephritis (PIGN) or poststreptococcal glomerulonephritis (PSGN). It can be a risk factor for future albuminuria.
Scarlet feverScarlet fever, also known as scarlatina, is an infectious disease caused by Streptococcus pyogenes, a Group A streptococcus (GAS). The infection is a type of Group A streptococcal infection (Group A strep). It most commonly affects children between five and 15 years of age. The signs and symptoms include a sore throat, fever, headache, swollen lymph nodes, and a characteristic rash. The face is flushed and the rash is red and blanching. It typically feels like sandpaper and the tongue may be red and bumpy.
