Almost all bacteria have an identifying first and last name, but these names are written with the last name first. The family name (the genus) is always capitalized. The individual's name (the species) is not. For example, Streptococcus salivarius and Streptococcus pyogenes. Streptococcus is the family name; pyogenes is the name of the particular family member. Salivarius is its cousin's given name. The family is often abbreviated: S. pyogenes, S. salivarius.
This same system of classification is used to identify birds, animals, plants and humans (Homo sapiens).
It has been estimated that 60% of all human infections are caused by viruses. They are the simplest, yet least understood of all the microbes. However, new and better techniques to study viruses continue to evolve. Most viral infections are untreatable, and what “antiviral” drugs or vaccines that are available, are limited. The control of viral infections is difficult at best and more often than not, requires that prevention techniques be employed to prevent the transmission and spread of disease.
WHAT ARE VIRUSES? ARE THEY ALIVE?
Viruses are particles composed of genetic material, (e.g. DNA/RNA), lipids, (fats), and a protein wall which protects this material. Unlike bacteria, viruses lack the ability to grow or replicate on their own. Virologists have said that viruses are not “alive”. They require a living host, (like a person), or a cell to support their replication. They are able to enter a cell and then take over that cell, directing it to make more virus particles. Some viral infections result in the eventual death of the host as in smallpox or rabies, while others allow the host to continue to live even after infection (as with the common cold).
Microbiology terms — Pathogenic terms
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Adenovirus (Ad'-e-no-virus) — A group of viruses that cause respiratory or gastrointestinal disease; Adenovirus Type 2 is a standard commonly-used test organism/ for disinfection efficacy.
Aerobe (air'-ob) — Microorganism that requires air (oxygen) for growth.
Agar — A common type of bacterial/fungal culture medium.
Algae (algee) — Microscopic plants; the simplest of plants containing chlorophyll and requiring sunlight.
Anaerobe (an'-e'robe) — Microorganism that grows without air (oxygen).
Antiseptic — A substance that prevents or inhibits the growth of microorganisms, particularly on skin.
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Bacilli (ba-sil-i) (singular: bacillus) — A rodshaped bacterium.
Bacteria (singular: bacterium) — Microorganisms, germs
Bactericide — Any agent that kills bacteria.
Bacteriostat — An agent that prevents the growth of bacteria but does not kill it.
Botulism (botsh'-e-lism) — Food poisoning due to the toxin Clostridium botulinum.
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Candida albicans (can'-di-da al'-bi-cans) — A yeast-like fungus; a common organism for fungicidal testing, causes infection in humans.
Carrier — A person, in apparent good health, who carries or harbors a pathogenic icroorganism.
Cell Wall — Outer "border" of a bacterial cell; functions as a kind of skin for the cell (only found in plant cells).
Cidal (si'-dul) — Suffix meaning the ability to kill (bactericidal, fungicidal, etc.).
Clostridium difficile (klo-strid'-ee-um dif'- ceel) — Spore-forming Gram positive organism capable of causing infectious diarrhea.
Clostridium tetani (klo-strid'-ee-um tet'-an-ee) — Gram positive organism used in testing. See Tetanus.
Cocci (kock'-si) (singular: coccus) — A spherical bacterium.
Colony — A visible growth of microorganisms on a culture medium.
Contamination — Entry of undesirable organisms into some material or object.
Corrosion — Process of gradual eating away by chemical action chemical action.
Corynebacterium diphtheriae (kor-in-e-bakter-ium dif-theer'-ee-i) — Gram positive bacteria used as a test organism in germicidal testing; causes diphtheria.
Culture Medium (plural: Media) — Any preparation or substance used to grow bacteria.
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Disinfection, Disinfectant — The process (disinfection) and means (disinfectant) of killing pathogenic organisms including bacteria, fungi and viruses, exclusive of spores.
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Enterobacter aerogenes (enter-o-bak'-ter air-ah'-jen-eez) — A Gram negative bacteria that causes intestinal disorders.
Escherichia coli (esh-er-eek'-ee-a kol'-ie) — A Gram negative organism that causes urinary tract infections and diarrhea; a standard test organism for disinfection efficacy.
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Fomites (foam'-ites) — Any inanimate object or substance, other than food, that harbors or carries infectious organisms.
Fungi (fun-ji) (singular: fungus)— Vegetative, organisms, includes mushrooms, molds, yeasts, as well as pathogenic forms.
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Germicide — Kills germs (synonomous with Disinfectant)
Glutaraldehyde (gloo-ter-al'-de-hide) — A chemical relative of formaldehyde, used for disinfection or cold sterilization of medical instruments (devices), typically soaked for 10 hours.
Gram Stain — Classification of bacteria by their reaction to staining. A dye is applied to bacteria and those that remain permanently stained purple or violet are Gram positive. If the stain is readily removed and counter-stained pink, the bacteria is called Gram negative.
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Incubation (in-cube-a'-shun) — Maintaining cultures of microorganisms at a temperature favorable to their growth.
Influenza A2 — A virus; commonly used organism for virucidal testing, causes flu.
Inhibit — To hold in check, restrain (a bacteriostat inhibits the growth of bacteria).
Iodophor — An iodine-based product used in antiseptics or disinfectants.
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Klebsiella pneumonia (kleb-see-el'-la newmoan'-ee-i) — A Gram negative organism, causes pneumonia, intestinal and respiratory infections; a standard test organism.
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Media — (See Culture Medium.)
Microbes — A minute life form; microorganism, esp. one that causes disease.
Microbiologist (Microbiology) — A specialist (field of work) that deals with microorganisms nd their effects on other forms of life.
Micron — A measure of length, 1/1000 of a millimeter or about 1/25,000 of an inch.
Mildew — A growth, usually white or black, produced by fungus.
Mold — A woolly growth, produced by fungus.
Mycobacterium tuberculosis (my-co-bac-teeree-um toob-er-ku-lo-sis) — An acid fast mycobacterium that causes tuberculosis (TB).
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Neisseria catarrhalis (ni-seer'-e-ah kat-ahral'-is) — A Gram negative cocci bacteria, a normal inhabitant of the mucous membrane in the respiratory tract.
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Organism — Any individual animal, plant or bacterium.
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Pasteurization (pas-tur-iz-a'-shun) — The process of heating milk (or other liquids) to 60ºC in order to kill pathogenic bacteria and inhibit other bacterial growth.
Pathogen — Any disease-producing microorganism.
pH — A symbol used to express the measure of alkalinity and acidity. A pH of 7 is the neutral point; above 7 alkalinity increases, below 7 acidity increases.
Phenol Resistance — A standard for determining the viability or strength of a specific culture (strain) of bacteria.
Plasma Membrane — A membrane inside the cell wall which picks up dye or stain and makes the cell visible under the microscope.
Preservative — A substance used in food, drugs, etc., to prevent decay or decomposition.
Proteus vulgaris (pro-tee-us vul-gar'-is) — A Gram negative organism that causes urinary tract infections and skin disorders; a common testing organism
Protoplasm — The essential material of all plant and animal cells; the living interior of the cell.
Pseudomonas aeruginosa (sood-o-moan'-us air-oo-jin-o'-sa) — A Gram negative organism that causes urinary tract, burn and wound infections; a primary test organism. It is a common cause of hospital infections.
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Respiratory, Respiratory Tract — The organs involved in breathing, including the lungs.
Rodac Testing — The use of a plastic, disposable plate into which a culture medium is poured and bacteria pressed nto the gelled surface for incubation and counting. Used primarily on flat surfaces (floors) in onfood areas.
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Salmonella choleraesuis (somon-el'-la kall-er-uh-soo'-is), paratyphi (para-ti'-fee), shottmuelleri (shot-mool'-er-i) — Gram negative organisms. Salmonella choleraesuis is a primary test organism that causes gastroenteritis, enteric fever and pneumonia.
Sanitizer — A product used to reduce the number of bacteria, particularly in food-service areas, to a level specified by public health authorities.
Serratia marcescens (ser-s-tee'-a mar-ses'-ens) — Gram negative rod-shaped bacteria found in water, soil, milk and food; a common test organism.
Shigella dysenteriae (shi-gel'-la dis-en-ter'-ee'-i) — Gram negative bacilli causing dysentery (diarrhea) in humans.
Spirilla — Spiral, curved or corkscrew shaped bacteria.
Spirochetes — Same as Spirilla.
Spore — A hard shell-like cell structure of certain rod-shaped bacteria which is an inactive form and is the most resistant of all living things to heat, disinfectants and drying. Can only be destroyed by sterilization.
Staphylococcus aureus (staf-il-o-kock'-us oar'-ee-us) — A Gram positive organism; one of the most common causes of hospital infections; causes infections in any organ or tissue. A primary test organism.
Sterilization, Sterilizer — The process or method of killing all forms of microbial life, including spores.
Streptococcus pyogenes (strep-to-kok'-us piah'-gen-ees) — Gram positive organism; pathogenic in humans.
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Tetanus — An acute infectious disease caused by Clostridium tetani.
Toxic/Toxin — A substance which has an effect like a poison in the body.
Trichophyton interdigitale also called Trichophyton mentagrophytes (try-co-fi'-ton or try-cough'- it-on inter-dij-i-tal'-lee, menta-grow-feet'-ees) — Fungus which causes athlete's foot fungus infections. Used as a test fungus.
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Vaccinia (vax-sin'-ee-a) — Virus used in testing. Affects only cattle, not humans. Since vaccinia is similar to smallpox in many ways, it is used as a model for the smallpox virus. Smallpox is usually spread by direct contact with clinical cases but it may result indirectly by handling clothing, bedding or hard surfaces soiled by the patient. Infection usually originates in the upper respiratory tract, followed by headache, fever, generalized pain and, ultimately, the appearance of the pox lesions over the body.
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To learn more about Pathogenic (disease causing) Germs and other Germ Protection subjects, please visit our partner at www.vnaa.org - Germ Protection Center.
Microbiology terms — Pathogenic terms
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Aspergillus niger — A common environmental mold. A major component of black mildew. Test organism for mold claims
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Campylobacter jejuni — This organism is found in the intestines of poultry (particularly chicken) and cattle. It can also be isolated from environmental water samples contaminated with their feces. Infections in humans cause diarrhea, abdominal pains, fever and, sometimes, vomiting. Blood may be present in the stool, particularly in children. Infections can be acquired through consumption of contaminated water or food products such as poorly cooked poultry and unpasteurized milk. Handling ofanimals, including household pets, has also been implicated as a source of human infections.Transmission among family members and institutionalized patients has been reported.
Candida albicans (can'-di-da al'-bi-cans) — Causes mild to severe or chronic superficial infections of skin, nails and mucous membranes in individuals with normal immune defenses, as well as serious systemic infections in debilitated patients. Frequently present as members of the normal flora of the mouth, throat, large intestine, vagina and skin and are often contaminants in exudates or other specimens.
Canine Parvovirus (ka-nin par-vo-vi'-rus) — This virus causes myocarditis in dogs characterized by sudden death, usually without any clinical signs. It is resistant to many disinfectants.
Clostridium difficile (klo-strid'-ee-um dif'-ceel) — This Gram positive, rod-shaped, spore-forming bacterium has been associated with outbreaks of diarrhea in patients receiving antibiotic therapy. It is the causative agent of Pseudomembranous colitis (severe diarrhea).
Corynebacterium diphtheriae (kor-in-e-bak- ter-ium dif-theer'-ee-i) — Produces a toxin that is the cause of diphtheria. Also produces infections of the skin, eyes and ears. This organism is found in the pharynx of humans.
Coxsackie Virus — Coxsackie Virus may be responsible for herpangina, aseptic meningitis, pleurodynia, myalgia, orchitis and myocarditis. This virus is resistant to most disinfectants.
Cytomegalovirus (CMV) — CMV infections are common and usually asymptomatic. Those at risk are individuals with HIV or some other underlying illness and pregnant women. The virus may infect the unborn fetus posing a threat to the child. CMV shedding from urine and saliva occurs primarily from children, and is prevalent in day care centers.
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Echovirus (ek'-o vi'-rus) — This organism is pathogenic causing urinary tract, respiratory, wound, blood and central nervous system infections. It is found in water, sewage, soil, dairy products and feces of humans and animals.
Enterobacter aerogenes (enter-o-bak'-ter air-ah'-jen-eez) — A Gram negative organism that causes urinary tract infections and diarrhea; a standard test organism.
Enterococcus faecalis (enter-o-kok'-us fek'- al-is) — (formerly Streptococcus faecalis) — Found in feces of humans and other warm- blooded animals. Occasionally the cause for urinary tract infections and sub-acute endocarditis. Usually infects individuals with underlying medical problems or the elderly.
Escherichia coli (esh-er-eek'-ee-a kol'-ie) — Causes diarrhea in infants and adults. It can also be responsible for urinary tract infections and septicemia. It is found in feces, soil and polluted water. E. coli 0157:H7 strain can cause Hemolytic Uremic Syndrome, resulting in kidney and other organ damage.
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Hepatitis A Virus (HAV) (hep'-ah-ti'-tis A vi'- rus) — Previously referred to as “infectious hepatitis”. Clinical expression of the disease is extremely variable from asymptomatic infection to hepatitis and even death. Symptoms include low-grade fever, fatigue, myalgia, anorexia and vomiting. Symptoms may be followed by clinical jaundice. Hepatitis A Virus is primarily spread by the fecal-oral route. It survives well on environmental surfaces and is resistant to most disinfectants. It is a recognized problem in day care centers.
Hepatitis B Virus (HBV) (hep'-ah-ti'-tis B vi'- rus) — Previously referred to as “serum hepatitis”. Can cause acute or chronic, symptomatic or asymptomatic hepatitis, depending on an individual's immune response. Major source of transmission is blood and/or needles, but the virus is also found in semen, saliva, milk, vaginal and menstrual secretions and amniotic fluid. HBV has a long incubation period and an insidious onset. Symptoms are similar to those observed with the Hepatitis A Virus.
Hepatitis C Virus (HCV) (hep'-ah-ti'-tis C vi'- rus) — Is the major cause of post-transfusion hepatitis, and is spread by blood or sexually (similar to HBV transmission). HCV can cause acute or chronic infections. Unlike HBV, the tests available for HCV cannot detect a current acute case of HCV, and this has frustrated the development of effective screening procedures for the protection of blood bank supplies.
Hepatitis D Virus (HDV)(hep'-ah-ti'-tis D vi'- rus) — Also referred to as “delta hepatitis”. Hepatitis D Virus is a defective satellite virus that can replicate only in HBV-infected cells and, therefore, occurs only in patients who have active Hepatitis B Virus infections. In a sense, it is a viral parasite. HDV, like HBV and HCV, is also transmitted parenterally and sexually.
Hepatitis E Virus (HEV) (hep'-ah-ti'-tis E vi'- rus) — Also referred to as “enteric hepatitis”, and is also classified as a non-A, non-B Hepatitis Virus. It is predominately spread by the fecal-oral route, especially in contaminated water. Symptoms and course of HEV are very similar to Hepatitis A Virus, causing only acute disease. HEV is most problematic in developing countries (India, Mexico, Nepal), and the infection is especially serious for pregnant women.
Herpes Simplex Virus (her'-pe ¯z sim'-pleks' vi'- rus) — HSV-1 causes skin lesions above the waist such as cold sores, infections of the eyes, ears and face. HSV-2 infects the genitalia and surrounding area. Crossover, however, can occur. The virus usually enters the body by the lips, mouth, skin, conjuctival sac or genitals. It remains latent and is awakened into activity by various hormonal, traumatic and other factors such as fever. Transmission is by direct contact, by kissing, by sexual intercourse and by formites such as glassware, cutlery, soap and towels. Studies suggest that overcrowding, as in orphanages and other institutions favors the transfer of virus. Serious eye infections can lead to encephalitis.
Human Immunodeficiency Virus (HIV-1) — HIV-1 is the causative agent of acquired immuno- deficiency syndrome (AIDS). The infection starts out as a mild case of flu with fever and malaise. After a dormant period of months to years, the disease progresses to AIDS, destroying the immune system, allowing the individual to become susceptible to a host of bacterial, viral, fungal and parasitic infections.
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Influenza A2 and B — A virus; commonly used organism for virucidal testing, causes flu.
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Klebsiella pneumonia (kleb-see-el'-la new-moan'-ee-i) — This particular organism is responsible for approximately 2% of all bacterial pneumonia. It also causes infections of the urinary and respiratory tracts, normally found in the intestinal tract of humans and animals.
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Listeria monocytogenes (lis'-ter'-e-ah mon'-o-si'-to-je¯n-z) — This organism is widely distributed in the environment and has often been isolated from soil, plants, decaying vegetation, silage, water and sewage. It has also been isolated from raw or processed foods including dairy products, meats, vegetables and seafood, as well as from the food-processing environment. Infection occurs mainly through ingestion of contaminated food. A few limited, nonfood related outbreaks in nurseries have been described. In humans Listeria monocytogenes mainly causes meningitis, encephalitis or septicemia in nonpregnant adults. In pregnant women, it often causes an influenza- like illness that, if unrecognized and untreated, may infect the fetus resulting in abortion, stillbirth or premature birth of an infected child.
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Mycobacterium tuberculosis (my-co-bac-teer-ee-um toob-er-ku-lo-sis) — Causative agent of tuberculosis, also known as TB. It is spread from person-to-person through inhalation of infectious airborne particles. These particles, called droplet nuclei, are produced when coughing, sneezing, speaking or singing. TB is more easily transmitted in closed air spaces where ventilation is poor. Symptoms include weight loss, night sweats, loss of appetite and blood in sputum.
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Neisseria elongata (ni-seer'-e--ahe ¯-lon-ga'- ta) — A short, Gram negative rod which often occurs as a diplobacillus. The natural habitat of these organisms is the mucous membranes of warm blooded animals, primarily the nasopharynz and throat areas. The primary pathogens in this group are N. gonorrhoeae and N. meningitidis.
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Parainfluenza virus (par'-ah-in'-floo-en'-za vi'-rus) — Causes upper respiratory disease in children and adults. It is transmitted through infected respiratory secretions through close person-to-person contact and airborne droplets.
Poliovirus (po'-le ¯-o vi'-rus) — Poliovirus is the causative agent for poliomyelitis, which is an inflammation of the brain and spinal cord resulting in paralysis. Poliovirus is also one of the causes of aseptic meningitis. It is known to be resistant to most disinfectants.
Prion — Abnormal protein that forms in the brain causing neurodegenerative diseases such as Creutzfeldt-Jakob Disease (CJD) in humans or bovine spongiform encephalopathy (BSE) in cows. Very difficult to inactivate, requires special procedures.
Proteus vulgaris (pro-tee-us vul-gar'-is) — This organism causes primary and secondary infections in debilitated persons of the urinary tract, burns, respiratory tract, eyes, ears and throat. It is found in manure, soil and polluted water.
Pseudomonas aeruginosa (sood-o-moan'-us air-oo-jin-o'-sa) — An opportunistic or primary hospital pathogen. When introduced into areas with people lacking normal defenses (i.e. burn unit), causes eye and wound infections, diarrhea and burn infections. It has worldwide distribution and is found in water, soil, on plants and, occasionally, in feces.
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Respiratory Syncytial Virus (RSV) — RSV is the most important cause of pneumonia and bronchiolitis in infants and small children. Like most respiratory viruses, RSV causes a range of respiratory illnesses, the most common being a cold with profuse rhinorrhea. Some infants (25-40%) develop lower respiratory tract disease with 1-2% requiring hospitalization. RSV is spread through person-to-person contact and contact with contaminated environmental surfaces.
Rhinovirus (ri'-no vi'-rus) — One of the causes of the common cold, an upper respiratory tract infection that results in a headache, chills, malaise and runny nose. Spread by person-to- person contact as well as contact with environmental surfaces.
Rotavirus (ro-ta vi'-rus) — Rotavirus is spread by the fecal-oral route. It is the leading cause of diarrhea in children under 2 years of age causing diarrhea, vomiting, fever and abdominal pain. The virus is very stable in the environment and can remain infectious on surfaces for up to 10 days. It is very resistant to many disinfectants.
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Salmonella choleraesuis (somon-el'-la kall-er- uh-soo'-is),
Salmonella paratyphi (para-ti'- fee), and
Salmonella schottmuelleri (shot- mool'-er-i) — Members of the genus Salmonella are causative agents of a variety of infections ranging from simple gastroenteritis ffood poisoning) to severe illnesses such as enteric fever, bacteremia, pneumonia, meningitis, typhoid-like infection and infections of body organs. They are a leading cause of bacterial diarrhea in the United States. It is highly associated with chicken and can be found in food, water, soil and feces.
Serratia marcescens (ser-s-tee'-a mar-ses'- ens) — An opportunistic pathogen for hospitalized patients causing infections of wounds, blood, the central nervous system and the respiratory and urinary tracts. It is found on plants, in soil, water and in the digestive tract of humans and animals.
Shigella dysenteriae (shi-gel'-la dis-en-ter'- ee'-i) — This is the cause of bacillary dysentery characterized by severe cramping, abdominal pain and diarrhea accompanied with blood and mucus. It is one of the most common causes of diarrhea in the United States Shigella can be transmitted by food, fingers, feces and flies.
Staphylococcus aureus (staf-il-o-kock'-us oar'-ee-us) — This organism is responsible for post-operative wound infections, boils, carbuncles, impetigo, pneumonia, osteomyelitis, meningitis, endocarditis, bacteremia, various abscesses, food poisoning and toxic shock syndrome. It is found on skin, in the genital tract and nasal membranes.
Streptococcus salivarius (strep-to-kok'us sal'- i-vi'-rus) — Isolated from blood, causes endocarditis. Found in the mouth and associated with feces.
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Trichophyton mentagrophytes (try-co-fi'-ton men-ta-grow-feet'-ees) — A common cause of athlete's foot. Athlete's foot is spread through the use of common showers and dressing rooms.
Tuberculosis — (See Mycobacterium tuberculosis.)
Trichophyton interdigitale also called Trichophyton mentagrophytes (try-co-fi'-ton or try-cough'- it-on inter-dij-i-tal'-lee, menta-grow-feet'-ees) — Fungus which causes athlete's foot fungus infections. Used as a test fungus.
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Vibrio Cholerae (vib'-re-o kol'er-ah) — An acute bacterial enteric disease acquired through ingestion of contaminated food or water. Most sporadic cases in the United States have resulted from raw or inadequately prepared seafood. It is becoming more of a threat in the United States due to increases in imported foods.
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