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|Purpose||diagnose bacteria or fungal infection in throat|
A throat culture is a laboratory diagnostic test that evaluates for the presence of a bacterial or fungal infection in the throat. A sample from the throat is collected by swabbing the throat and placing the sample into a special cup (culture) that allows infections to grow. If an organism grows, the culture is positive and the presence of an infection is confirmed. The type of infection is found using a microscope, chemical tests, or both. If no infection grows, the culture is negative. Common infectious organisms tested for by a throat culture include Candida albicans known for causing thrush and Group A streptococcus known for causing strep throat,scarlet fever, and rheumatic fever. Throat cultures are more sensitive (81% sensitive) than the rapid strep test (70%) for diagnosing strep throat, but are nearly equal in terms of specificity.
A throat culture may be done to investigate the cause of a sore throat. Most sore throats are caused by viral infections. However, in some cases the cause of a sore throat may be unclear and a throat culture can be used to determine if the infection is bacterial. Identifying the responsible organism can guide treatment.
The person receiving the throat culture is asked to tilt his or her head back and open his or her mouth. The health professional will press the tongue down with a tongue depressor and examine the mouth and throat. A clean swab will be rubbed over the back of the throat, around the tonsils, and over any red areas or sores to collect a sample.
The sample may also be collected using a throat washout. For this test, the patient will gargle a small amount of salt water and then spit the fluid into a clean cup. This method gives a larger sample than a throat swab and may make the culture more reliable.
A culture for Streptococcus pyogenes can take 18–24 hours when grown at 37 degrees Celsius (body temperature).
Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Firmicutes. 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.
A group A streptococcal infection is an infection with group A streptococcus (GAS). Streptococcus pyogenes comprises the vast majority of the Lancefield group A streptococci, and is often used as a synonym for GAS. However, S. dysgalactiae can also be group A. S. pyogenes is a beta-hemolytic species of Gram positive bacteria that is responsible for a wide range of both invasive and noninvasive infections.
Scarlet fever is a disease resulting from a group A streptococcus infection, also known as Streptococcus pyogenes. The signs and symptoms include a sore throat, fever, headaches, swollen lymph nodes, and a characteristic rash. The rash is red and feels like sandpaper and the tongue may be red and bumpy. It most commonly affects children between five and 15 years of age.
Streptococcal pharyngitis, also known as strep throat, is an infection of the back of the throat including the tonsils caused by group A streptococcus (GAS). Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in 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.
Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.
Rheumatic 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. The damaged valves may result in heart failure, atrial fibrillation and infection of the valves.
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagnostic methods used as a research tool in molecular biology.
Tonsillitis is inflammation of the tonsils, typically of rapid onset. It is a type of pharyngitis. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and large lymph nodes around the neck. Complications include peritonsillar abscess.
A blood culture is a medical laboratory test used to detect bacteria or fungi in a person's blood. Blood is normally sterile, and the presence of microbes in the blood often indicates a serious bloodstream infection such as a bacteremia, or fungemia, that can result in sepsis.
Antibiotic sensitivity testing or antibiotic susceptibility testing is the measurement of the susceptibility of bacteria to antibiotics. It is used because bacteria may have resistance to some antibiotics. Sensitivity testing results can allow a clinician to change the choice of antibiotics from empiric therapy, which is when an antibiotic is commenced based on clinical suspicion about the site of an infection and common bacteria that cause this, to directed therapy, which is when an antibiotic is commenced based on knowledge of a causative organism and its sensitivities.
A sputum culture is a test to detect and identify bacteria or fungi that infect the lungs or breathing passages. Sputum is a thick fluid produced in the lungs and in the adjacent airways. Normally, fresh morning sample is preferred for the bacteriological examination of sputum. A sample of sputum is collected in a sterile, wide-mouthed, dry, leak-proof and break-resistant plastic-container and sent to the laboratory for testing. Sampling may be performed by sputum being expectorated, induced, or taken via an endotracheal tube with a protected specimen brush in an intensive care setting. For selected organisms such as Cytomegalovirus or "Pneumocystis jiroveci" in specific clinical settings a bronchoalveolar lavage might be taken by an experienced pneumologist. If no bacteria or fungi grow, the culture is negative. If organisms that can cause the infection grow, the culture is positive. The type of bacterium or fungus is identified by microscopy, colony morphology and biochemical tests of bacterial growth.
Group B streptococcal infection, also known as Group B streptococcal disease or just Group B strep, is the infection caused by the bacterium Streptococcus agalactiae. GBS infection can cause serious illness and sometimes death, especially in newborns, the elderly, and people with compromised immune systems.
The rapid strep test (RST) is a rapid antigen detection test (RADT) that is widely used in clinics to assist in the diagnosis of bacterial pharyngitis caused by group A streptococci (GAS), sometimes termed strep throat. There are currently several types of rapid strep test in use, each employing a distinct technology. However, they all work by detecting the presence of GAS in the throat of a person by responding to GAS-specific antigens on a throat swab.
Due to their natural composition, cane musical reeds may hold bacteria or mold, which can affect one's health and the quality of sound produced. Some of the basic instruments that use reeds include the clarinet, saxophone, oboe and bassoon. Proper care of reeds will extend their longevity and control bacterial growth.
The Centor criteria are a set of criteria which may be used to identify the likelihood of a bacterial infection in adult patients complaining of a sore throat. They were developed as a method to quickly diagnose the presence of Group A streptococcal infection or diagnosis of streptococcal pharyngitis in "adult patients who presented to an urban emergency room complaining of a sore throat."
Influenza-like illness (ILI), also known as flu-like syndrome/symptoms, is a medical diagnosis of possible influenza or other illness causing a set of common symptoms.
Throat irritation can refer to a dry cough, a scratchy feeling at the back of the throat, a sensation of a lumpy feeling, something stuck at the back of the throat, or possibly a feeling of dust in the throat. The symptoms are unpleasant and usually temporary, but occasionally signifies a more serious health issue, such as laryngitis.
Bacteriophage T12 is a bacteriophage that infects the bacterial species Streptococcus pyogenes, and converts a harmless strain of bacteria into a virulent strain. It carries the speA gene which codes for erythrogenic toxin A. speA is also known as streptococcal pyogenic exotoxin A, scarlet fever toxin A, or even scarlatinal toxin. Note that the name of the gene "speA" is italicized; the name of the toxin "speA" is not italicized. Erythrogenic toxin A converts a harmless, non-virulent strain of Streptococcus pyogenes to a virulent strain through lysogeny, a life cycle which is characterized by the ability of the genome to become a part of the host cell and be stably maintained there for generations. Phages with a lysogenic life cycle are also called temperate phages. Bacteriophage T12, a member of a family of related speA-carrying bacteriophages, is also a prototypic phage for all the speA-carrying phages of Streptococcus pyogenes, meaning that its genome is the prototype for the genomes of all such phages of S. pyogenes. It is the main suspect as the cause of scarlet fever, an infectious disease that affects small children.
Granada medium is a selective and differential culture medium designed to selectively isolate Streptococcus agalactiae and differentiate it from other microorganisms. Granada Medium was developed by Dr. Manuel Rosa-Fraile et al. at the Service of Microbiology in the Hospital Virgen de las Nieves in Granada (Spain).
In microbiology, the term isolation refers to the separation of a strain from a natural, mixed population of living microbes, as present in the environment, for example in water or soil flora, or from living beings with skin flora, oral flora or gut flora, in order to identify the microbe(s) of interest. Historically, the laboratory techniques of isolation first developed in the field of bacteriology and parasitology, before those in virology during the 20th century. Methods of microbial isolation have drastically changed over the past 50 years, from a labor perspective with increasing mechanization, and in regard to the technology involved, and hence speed and accuracy.