MICRO BIO 2100 Dr. Wilk’s Note Guide for Microbiology Unit 10 USLO 10.1

MICRO BIO 2100 Dr. Wilk’s Note Guide for Microbiology Unit 10 USLO 10.1 Vocabulary to define: • Pleomorphic-capable of having a variety of shapes • Endothelial cells-an epithelial cell found in blood vessels and lining the heart Bacterial Diseases of the digestive system • Bacillus cereus o Disease associated with pathogen-food poisoning/intoxication-found in pasta or rice o Signs and symptoms-symptoms begin within a few hours & include nausea, pain & abdominal cramps. Vomiting or diarrhea may also be present depending on the enterotoxin present. Has been known to cause death. o Virulence Factors-makes 2 enterotoxins ▪ One causes vomiting ▪ Other causes diarrhea o Transmission-found in the soil & is often associated with grains. The bacteria in food will form and endospore. Vegetative bacteria make enterotoxins. Enterotoxins can be secreted into food that is left out too long or not cooked properly. o Treatment-antibiotics and fluids • Bacillus anthracis o Disease associated with pathogen-anthrax o Signs and symptoms-rare in the US, prompt treatment is necessary for good outcomes. Without treatment, gastrointestinal anthrax is fatal in about 40% of cases. o Virulence Factors-has a capsule, lethal toxin (LT), and edema toxin (ET). o Transmission-enters through the GI system causes gastrointestinal anthrax. Can be contracted through eating meat contaminated with the bacterium. o Treatment-antibiotics; penicillin, doxycycline, ciprofloxacin • Clostridium botulinum o Disease associated with pathogen-botulism o Signs and symptoms-nausea, vomiting, constipation, diarrhea, abdominal cramps, difficulty swallowing, drooping eyelids, blurred vision o Virulence Factors-usually the endospore of C. botulinum are in food and germinate within the food allowing the production of the neurotoxin. The person ingests the neurotoxin and enters the bloodstream causing the paralysis at the NMJ. Forms the neurotoxin BoNT. o Transmission-Associated with improperly canned foods. The neurotoxin is ingested through the digestive tract. o Treatment-Administration of the anti-toxin for the BoNT. This will only stop progression and not reverse any damage to the NMJ already done. Over time, neurological functions may be regained over a period of months or years. • Clostridium difficile o Disease associated with pathogen-C-diff infection o Signs and symptoms-toxins cause damage to intestinal tract causing a pseudomembranous colitis, watery and or bloody diarrhea, stomach cramping, dehydration, fever, and loss of appetite. In older people, death can result. o Virulence Factors-produced toxins TcdA and TcdB o Transmission-C. diff is part of the normal microbiota of normal healthy people. When antibiotics disrupt the balance of the normal intestinal microbiota, Clostridium difficile is allowed to overgrow causing symptoms. Also caused by unwashed hands. Hand sanitizer does not kill spores. o Treatment-Stopping antibiotics and using metronidazole or vancomycin. Other treatment options may include fecal transplant from a healthy donor. Probiotics can help to preserve the normal flora once the infection is under control. • Clostridium perfringens o Disease associated with pathogen-Gastroenteritis o Signs and symptoms-diarrhea and abdominal cramps usually develop within 8-12hrs and resolves within 24hrs o Virulence Factors-enterotoxins o Transmission-Found in undercooked food and the endospore will germinate and secrete enterotoxins. Endospores that are ingested can also germinate in the intestines. o Treatment-Supportive care and replacement of electrolytes • Escherichia coli o Disease associated with pathogen-food poisoning o Signs and symptoms—watery diarrhea, occasionally with a fever or vomiting o Virulence Factors-fimbriae allow attachment, more virulent strains produce enterotoxins, toxins are similar to cholera or shiga toxins o Transmission-Normal inhabitant of lower GI tract. The most common means of transmission is through contaminated food or water from improper hand hygiene. o Treatment-most are self-limiting and only require supportive care such as replacing electrolytes. Other more virulent strains may require antibiotics, but these are rarely used due to the risk of antibiotic resistance and the potential of hemolytic urea syndrome. • Helicobacter pylori o Disease associated with pathogen-peptic ulcers o Signs and symptoms-can be an inhabitant of some people and be asymptomatic. Symptoms are nausea, lack of appetite, burping, bloating, and weight loss. Some people will develop ulcers and some have risk of stomach cancer. o Virulence Factors-Produces toxins Vac A. Attached using pili. Produces an exoenzyme urease to neutralize stomach acid and allow for the bacteria to survive. o Transmission-Transmitted through contaminated food or water. Recent research has shown it is possible to transmit between people from close contact or sharing food and drink. o Treatment-Triple therapy with antibiotics and an antacid to decrease stomach acid that the bacteria prefer. • Salmonella o Disease associated with pathogen-salmonellosis o Signs and symptoms-Diarrhea and stomach cramps, fever, nausea, vomiting, and headache. o Virulence Factors-Endotoxin, flagella, fimbriae, invasins, siderophores o Transmission-contaminated poultry and meat o Treatment-most of the time infection is self-limiting, but antibiotics can be used in debilitating cases. • Salmonella typhi o Disease associated with pathogen-typhoid fever o Signs and symptoms-headache, fever, nausea, body aches, lethargy, rash. The mortality rate of untreated S. typhi is 10% o Virulence Factors-Endotoxin, capsule, chimeric A2B5 toxin, grows in macrophages and can be transported to the liver and gallbladder. o Transmission-transmitted via fecal-oral route from infected persons and poor hand hygiene. Many people can be asymptomatic and unknowingly pass the bacteria to others from dirty hands. o Treatment-antibiotics and fluids • Shigella o Disease associated with pathogen-shigellosis o Signs and symptoms-stomach cramps, fever, watery or bloody diarrhea. A serious sequela can be hemolytic urea syndrome. o Virulence Factors-it can escape the phagolysosome and survive in phagocytes. Produces shiga toxin. o Transmission-transmitted by the fecal-oral route or through contaminated food or water. o Treatment-usually supportive care but antibiotics can be used in severe cases • Staphylococcus aureus o Disease associated with pathogen-food poisoning/intoxication o Signs and symptoms-rapid onset of vomiting and diarrhea with most often resolving in 24hrs. o Virulence Factors-enterotoxin o Transmission-Food or dishes contaminated with S. aureus which can grow to produce a toxin that ends up in the food. The toxin is the cause of the illness, no the bacteria. Most often food with the bacteria is not stored properly allowing the bacteria to grow. o Treatment-usually not needed • Streptococcus mutans o Disease associated with pathogen-Often associated with dental decay (cavities) o Signs and symptoms-among the hundreds of bacteria that inhabit the mouth, it is the most important in the development of cavities. Through the process of fermentation, acid is produced which can erode the tooth enamel resulting in a cavity. These bacteria thrive on sugar as their primary food source. Diagnosis of the bacteria is not necessary to identify the damage their acidic products cause. Dental professionals use x-rays or clinical techniques for diagnosis of the cavity. o Virulence Factors-none o Transmission-N/A o Treatment-Repairing the cavity. It is more important to prevent the development of cavities be reducing the sugar available to Streptococcus mutans to use for fermentation. • Vibrio cholera o Disease associated with pathogen-cholera o Signs and symptoms-profuse diarrhea that can lead to dehydration and electrolyte imbalances o Virulence Factors-toxin coregulated pilus (TCP), cholera toxin (CT) o Transmission-transmitted through contaminated water and food o Treatment-electrolyte replacement is needed but otherwise, it is self-limiting. Antibiotics are only used in severe cases. Prevention by proper sanitation is best to prevent infection. Bacterial diseases of the circulatory/lymphatic systems • Borrelia burgdorferi o Disease associated with pathogen-Lyme Disease o Signs and symptoms-Bulls-eye rash, fever, muscle stiffness, malaise, and headache. Untreated infections can result in a second stage with sever headache, neck stiffness, facial paralysis, joint pain, and heart problems. Late stage symptoms include arthritis, meningitis, encephalitis and altered mental states. o Virulence Factors-exploitation of immune system o Transmission-Bite of infected tick; mammals like deer and mice are the reservoir and the tick is the vector. o Treatment-antibiotics; doxycycline, amoxicillin, or cefuroxime axetil. • Ehrlichia chaffeensis o Disease associated with pathogen-Ehrlichiosis o Signs and symptoms-Rash and flu-like symptoms o Virulence Factors-Evade host innate defenses, including apoptosis, to take advantage of the host cells. o Transmission-Passed by lone-star tick. Deer most common reservoir. o Treatment-antibiotics; doxycycline • Francisella tularensis o Disease associated with pathogen-Tularemia or rabbit fever o Signs and symptoms-skin lesion will develop at the site of infection after 3 days. Fever, chills, headache, and small, swollen, and painful lymph nodes are also symptoms. o Virulence Factors-starts with infection of macrophages where the bacteria multiply and then find their way to other organs making granulomas. o Transmission-The reservoir is usually the rabbit or other small mammal. Infection can be obtained through the ingestion of contaminated meat or contact with an infected animal. Also, transmission through a vector (tick) is also possible. It is not a person to person pathogen but inhalation is a possible route of transmission and can cause severe infection. o Treatment-antibiotics; streptomycin, gentamicin, doxycycline, and ciprofloxacin. • Rickettsia o Disease associated with pathogen-Endemic typhus or murine typhus o Signs and symptoms-rash, chills, headache, fever lasting bout 2 weeks. Occasionally pneumonia-like symptoms are possible. o Virulence Factors- o Transmission-humans and flying squirrels are the reservoirs and the vector is body lice and other insects. Rats are the reservoir and the vector is the rat flea. o Treatment-antibiotics; azithromycin, doxycycline, tetracycline, or chloramphenicol • Rickettsia rickettsii o Disease associated with pathogen-Rocky Mountain Spotted Fever o Signs and symptoms-high fever, headache, body aches, nausea, and vomiting followed by rash. o Virulence Factors-invades host cells and quickly escape phagosomal vacuoles into host cell cytosol to evade phagosome-lysosome fusion, replication within the host cytoplasm, and exit from the host cell by actin-mediated motility. o Transmission-small rodents are reservoirs and the vectors are ticks. o Treatment-antibiotics; doxycycline • Yersinia pestis o Disease associated with pathogen-Bubonic plague o Signs and symptoms-sudden onset of fever, headache, hypotension, chills, and swollen lymph nodes with buboes. o Virulence Factors-bacteria replicate extracellularly in tissues following lysis of macrophages and hence, the microbial population in the affected host is enormous. o Transmission-humans and small mammals are the reservoir, vector is the flea. Another way to introduce the bacteria is through a cut allowing direct introduction to the bloodstream. Yersinia pestis can also be inhaled causing pneumonia. o Treatment-antibiotics; streptomycin and gentamicin, tetracyclines (especially doxycycline), and the fluoroquinolone ciprofloxacin. • Bacterial Diseases of the Nervous System • Clostridium botulinum o Disease associated with pathogen-Botulism o Signs and symptoms-nausea, vomiting, constipation or diarrhea, abdominal cramps, difficulty swallowing, drooping eyelids, & blurred vision. o Virulence Factors-usually the endospore of C. botulism is in food & germinate within the food allowing the production of the neurotoxin BoNT. o Transmission-Associated with improperly canned foods. The neurotoxin is ingested through the digestive tract. o Treatment- antibiotics, an antitoxin (a chemical antidote to the toxin) • Clostridium tetanus o Disease associated with pathogen-Tetanus o Signs and symptoms-spasms affecting the muscles and causing clenched jaws & fist, paralysis of the respiratory muscles, disturbance of heart function, & death. o Virulence Factors-toxin attacks the NMJ usually near the entry point. This forms a neurotoxin TeNT. Toxin eventually reached the CNS and causes spastic paralysis. o Transmission-classically associated with a rusty nail and a puncture wound. The reservoir is soil and the bacterium enter a wound and grown to produce the neurotoxin. o Treatment- There's no cure for tetanus. Treatment focuses on managing complications until the effects of the tetanus toxin resolve. Your doctor may give you a tetanus antitoxin, such as tetanus immune globulin. However, the antitoxin can neutralize only toxin that hasn't yet bonded to nerve tissue. Antibiotics. Your doctor may also give you antibiotics, either orally or by injection, to fight tetanus bacteria. • Listeria monocytogenes o Disease associated with pathogen-Listeriosis o Signs and symptoms-Usually asymptomatic & self-limiting. High risk groups are pregnant women, elderly, & newborns. Listeria can cause spontaneous abortion (miscarriage) & meningitis in the elderly and newborns. o Virulence Factors-surface proteins allows the bacteria to invade host cells usually M cells or Peyers patches. High jacking host cell’s actin allow it to move from cell to cell. o Transmission-found in soil and water where it can contaminate produce. Often found in fruits and vegetable but also deli meat and cheese. Transmitted by unpasteurized or improperly pasteurized milk and cheese products as well as from animals. o Treatment-self-limiting, antibiotics • Neisseria meningitidis o Disease associated with pathogen-Meningococcal meningitis o Signs and symptoms-petechial rash, headache, stiff neck, vomiting, fever, sensitivity to light and confusion. Comes on suddenly & can progress quickly causing neurological defects that can be irreversible. Sepsis can result leading to death. o Virulence Factors-believed to possess endotoxins responsible for symptoms o Transmission-part or normal microbiota in nasopharynx, transmitted person to person via close contact by respiratory droplets and often inhabits the nasopharynx without evidence of disease. o Treatment- • Streptococcus agalactiae o Disease associated with pathogen-Meningitis, neonatal meningitis, sepsis, pneumonia o Signs and symptoms-opportunistic transient pathogen of vagina and GI tract in healthy people, primary pathogen in newborns. o Virulence Factors-capsule, hemolysins, proteins for invasion and attachment, pore- forming toxin o Transmission-newborns are exposed through birth canal o Treatment- • USLO 10.2 Vocabulary to define: • Hepatitis- inflammation of the liver • Jaundice- yellowing of the skin due to liver malfunction • Meningitis- inflammation of the meninges of the brain and spinal cord • Encephalitis- inflammation of the brain • Prion- infectious protein • Immunoglobulin- antibodies; often used a prevention to gain passive immunity • Arbovirus- a virus spread by an insect (vector) • TORCH panel- a screening test in pregnancy to detect toxoplasmosis, CMV, Rubella, herpes and others. Hepatitis Virus Differentiate • Hep A- is caused by an RNA virus that passes among individuals by the fecal‐oral route, and the disease is sometimes called infectious hepatitis. • Hep B- also called serum hepatitis, is caused by a DNA virus that passes directly from person to person, primarily in blood and semen. • Hep C- Hepatitis C is caused by an RNA virus transmitted by blood and semen. Most cases are associated with transfusions. • Hep D- Delta hepatitis, also sometimes called hepatitis D, is related to an antigen called the delta antigen, which is a part of an RNA virus called the delta virus. Infection with this type of hepatitis accompanies infection with the hepatitis B virus because the delta antigen relies on the hepatitis B virus for its replication. Other viruses associated with the digestive system • Mumps- swelling of the infected gland causing pain and difficulty chewing, loss of appetite, fever, muscle pain, fatigue, and weakness. o Signs and symptoms-Sometimes causes meningitis, encephalitis, and or deafness. Sterility can result by infected gonads. o Transmission- in saliva and respiratory secretions, it replicates in the host's respiratory tract and causes swelling of one or both of the parotid glands below the ear and near the angle of the jaw. o Virulence-hemagglutinin and neuraminidase spikes; fusion protein for attachment. • Gastroenteritis- Viral gastroenteritis is a general expression for viral infection of the intestine. o Signs and symptoms- It can be caused by rotavirus or norovirus. Symptoms include watery diarrhea, mild stomach cramps, and fever. Usually mild and develop 12-48hrs after exposure. Dehydration is possible complication. o Transmission-passed from person to person, contaminated food and by fomites; fecal- oral transmission. o Virulence-non enveloped virus, low ID50, survive outside the body, antigenic drift. Viruses associated with the circulatory/lymphatic systems • Cytomegalovirus- Cytomegalovirus (CMV) is a common virus in people however, a healthy person's immune system usually keeps the virus from causing illness. o Signs and symptoms-Apprx 50% of people have been infected. Most are asymptomatic. Symptoms may include fever, fatigue, swollen glands, & sore throat. Immunocompromised people can have more serious complications of liver damage, retinal damage, tissue rejection, and even death. ▪ Congenital CMV occurs in infants born to infected mother. Their symptoms are rash, jaundice, microcephaly, low birth weight, hepatosplenomegaly, seizures, damage to the retina. Long term complications include hearing loss, developmental delay, vision loss, and seizures. o Transmission-through sexual contact and breast feeding; blood transfusions and organ transplants. Passage through the placenta or birth canal is also possible. o Virulence-proteins on the envelope allow attachment to host cells. • Ebola- Ebola Virus Disease (EVD) is a rare and deadly viral hemorrhagic fever found in people and nonhuman primates. o Signs and symptoms-fever, severe headache, muscle pain, cough, chest pain, sore throat. Later symptoms are abdominal pain, diarrhea, & vomiting. After 3 days, skin, GI organs, and mucous begins to hemorrhage. Then come delirium, stupor, coma, and death. o Transmission-originated in bats but has been passes from person to person via infected body fluids including blood, urine, saliva, vomit, or feces. It is a highly contagious. o Virulence-enveloped, attachment proteins • Infectious Mononucleosis- Epstein-Barr virus, or EBV, is one of the most common human viruses in the world. It spreads primarily through saliva and causes infectious mononucleosis, also called mono. Most people will get infected with EBV in their lifetime and will not have any symptoms. o Signs and symptoms-swollen lymph nodes, sore throat, fever, extreme fatigue. Spleen and liver enlargement are found later causing abdominal pain. o Transmission-close contact with infected people via saliva, blood, or semen. Usually found in teenagers and young adults. o Virulence-enveloped, proteins allow for attachment to B cell and epithelial cells. Can become latent. • HIV- The human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS) which interferes with the body's ability to fight infections. o Transmission- Humans are the reservoir for HIV and it is passed through blood and other body fluids like semen, vaginal secretions, and breast milk. The virus can be transmitted by exposure to contaminated blood through sexual contact, an open sore, sharing needles, and breast milk. o Signs and symptoms- ▪ Stage 1- Acute HIV, the symptoms are flu-like and can last a few weeks. CD4 cell count is around 500 cells/μL. The viral load is high and the person is very contagious. ▪ Stage 2- Latent stage, the virus is still replicating, but the patient feels well. The CD4 cell count is between 200 and 499 cells/μL. This stage can last for a decade, longer if the patient is receiving antiviral therapy. ▪ Stage 3- AIDS, the patient has symptoms of fever, chills, sweats, swollen lymph nodes, fatigue, and weight loss. The patient may also show AIDS indicated conditions like Pneumocystis pneumonia, Kaposi's sarcoma, TB, Toxoplasmosis, cryptosporidiosis, and many others. o Virulence-enveloped, integrase to join host cell chromosome; makes a provirus, protease to make viral proteins, infects and destroys CD4 helper T cells, high antigenic drift. Viruses associated with the nervous system • Describe each o Viral meningitis-is a complication of other viral infections ▪ Pathogen-a variety of viruses can cause this form of meningitis, including the mumps, measles viruses, influenza viruses, and herpes viruses ▪ Symptoms-stiff neck, headache, sensitivity to light, fever, nausea, vomiting, lethargy, and general feelings of being unwell o Prions-infectious proteins, Creutzfeldt-Jakob disease (CJD), Variant Creutzfeldt-Jakob disease (VCDJ), Bovine spongiform encephalopathy (BSE), Sheep Scrapie, Chronic wasting disease of the deer ▪ Transmission-ingestion of contaminated meat with nervous tissue, nervous system implants, blood transfusion, fomites. ▪ Symptoms-memory loss, changes in personality, insomnia, blurred vision, loss of coordination. May develop years after exposure and once symptoms appear, progression is quick. Neurological changes result in coma and lead to death. o West Nile virus-originated in Africa and was 1st found in the US in 1999. ▪ Transmission-reservoir is birds and mosquitos, vectors are also mosquitos ▪ Symptoms-often subclinical, mild symptoms include fever, headache, joint and muscle aches, vomiting, diarrhea or a rash. Small percentage of people present as meningitis or encephalitis. Mortality rate of 10%. o Zika Virus- In most cases, there are no symptoms. In a few cases, Zika can trigger paralysis (Guillain-Barré Syndrome). In pregnant women, it may cause subsequent birth defects. ▪ Transmission-monkeys were the original reservoir of the virus which was transmitted by the mosquito. Humans are now the reservoir and spread through sexual contact has been documented. Most common form of transmission by mosquito. ▪ Symptoms-mild, include fever, slight rash, conjunctivitis or red eyes. Muscle pain in some people and joint pain, headache and malaise may be present. In pregnant women the virus affects fetal brain development resulting in microcephaly. ▪ Virulence factors-envelopled, proteins for attachment to host cells o o Rabies- is a fatal but preventable viral disease. ▪ Transmission-usually through the bite of an infected animal. Contact with saliva of an infected animal or person is enough for transmission. The reservoirs are wild animals with the racoon being the most common. Rarely found in domesticated animals due to vaccination. ▪ Symptoms-discomfort at site of bite, fever, and headache. As the virus moves to the brain, either furious or paralytic rabies is the result and always fatal. Furious rabies victims show agitation, hyperactivity and hydrophobia due to muscle spasm of the throat making swallowing difficult, which also causes foaming of the mouth. Terror and confusion occur at the end stage of the disease process. The paralytic form starts with paralysis of muscles at the site of bite that progresses over time leading to coma and death. ▪ Virulence factors-enveloped, phospholipids on the envelop allow it to attach to host cells and enter. o Polio- is a disabling and life-threatening disease caused by the poliovirus. ▪ Transmission-spread by the fecal-oral route and is usually an intestinal illness. The virus is shed in the feces. It is discussed here due to the significant impact if it reaches the nervous system. ▪ Signs & symptoms-most are asymptomatic, a few have nausea, fever, and headache. Rarely it can infect the CNS. When it reaches the CNS throught the blood, the virus can replicate in the motor neurons of the spinal cord or cerebral cortex destroying the neurons and leading to flaccid paralysis. If it reaches the motor neurons of the respiratory muscle it could result in death. ▪ Virulence factors-non-enveloped, surface proteins for attachment, survives the acidic environment of the stomach. USLO 10.3 Vocabulary to define: • Cyst-protective coat parasites commonly use for surviving poor conditions • Oocyst- hardy, thick-walled stage of the life cycle of protozoan, contain a zygote • TORCH- A series of test in pregnancy for the presence of Toxoplasmosis, rubella, Cytomegalovirus, herpes, and others Fungal Diseases of the digestive system • Candid albicans- is a fungal infection caused by a yeast (a type of fungus) called Candida. Normally lives on the skin and inside the body, in places such as the mouth, throat, gut, and vagina, without causing any problems. o Signs and symptoms- are bloating after a meal, excessive gas and usually constipation. o Transmission-not between people, usually overgrowth of normal microbiota or antibiotic use. Most common in infants and immunosuppressed people. o Treatment-anti fungal rinses used as mouthwash or swallowed Protozoan diseases of the digestive system • Cryptosporidium hominis- It is an obligate parasite of humans that can colonize the gastrointestinal tract resulting in the gastroenteritis and diarrhea o Signs and symptoms-watery diarrhea, nausea, vomiting, cramps, fever, dehydration, and weight loss. o Transmission-through contaminated water sources like swimming pools or fresh bodies of water. Occasionally from food contaminated with the pathogen. The egg of the protozoan is shed in the feces of infected animals and humans in a cyst form. These can then be ingested or inhaled in a new host for a new cycle. o Treatment-oral rehydration therapy that resolves on its own in about a month. Medications can help eliminate diarrhea. Immunocompromised people can be treated with anti-parasitic drugs. • Giardia lamblia-is a microscopic parasite that causes the diarrheal illness o Signs and symptoms-some people are asymptomatic but others experience diarrhea, nausea, stomach cramps, gas, greasy stool o Transmission-attaches to host with a microtubule disk, absorbs host nutrients, cyst form, very low ID50. Giardia are found in fresh water. Mammals are the reservoir and as the protozoan is shed in the feces it can enter the water supply and be ingested in water/food. It can also pass person to person through the fecal-oral route. o Treatment-antiprotozoal drugs, some people clear the parasite without treatment in 2-6 weeks. • Entamoeba histolytica-disease caused by the parasite o Signs and symptoms-can be asymptomatic to severe amoebic dysentery. In severe cases, the abdomen becomes distended and there could be a fever. The pathogen can enter organ like the spleen, brain, genitourinary tract, or lungs. Pain can accompany inflammation of these organs. o Transmission-Is passed by fecal-oral route. Typically ingested through contaminated water but anything contaminated by the feces of an infected person can pass this pathogen. Secretes enzymes that destroy phagocytes and other cells. Low ID50. o Treatment-antiprotozoal drugs, one for the acute episode and a different drug to clear cysts. • Balantidium coli- is an intestinal protozoan parasite that causes the infection called balantidiasis o Signs and symptoms-most people are asymptomatic, immunocompromised people are likely to have severe disease, persistent diarrhea, dysentery, abdominal pain, weight loss, nausea, and vomiting. Perforation of the bowel is possible. o Transmission-Swine are the reservoir and it can be passed from contaminated water or food or contact with the animal. It is fecal-oral transmission between people. Moves by cilia, cyst form. o Treatment-when treatment is needed, antiprotozoal medications are used. Helminthic diseases of the digestive system • Enterobius vermicularis-Pinworm o Signs and symptoms-may be asymptomatic, abdominal pain, perianal itching, especially at night, keeps children awake. The adult female worm will exit through the anus and lay eggs at night. o Transmission-humans are natural reservoirs, eggs can be passed by the fecal-oral route. More than 1/3 of children have been affected. Most common during childhood due to poor handwashing. Eggs can also be passed through bedding and clothing as fomites. o Treatment-antihelminth drugs, all members of household should be treated and bedding washed to avoid reinfection. Attaches to the ileocecal colon area. • Taenia spp.-Tape worm o Signs and symptoms-can be asymptomatic to mild stomach pain, nausea, diarrhea, gas. Cysts formed in the muscle can cause local pain and if it reached the brain can be life- threatening. Attach to host using scolex. o Transmission-commonly found in pork and beef, Diphyllobothrium are found in fish. Passed through undercooked meat (through cysts in the muscles) and raw fish. Ingested eggs can develop into a mature tapeworm and shed eggs in the feces. o Treatment-antihelminth drugs • Trichinella spiralis-Roundworm o Signs and symptoms- can be asymptomatic to mild stomach pain, constipation or diarrhea, flu-like symptoms. Symptoms can appear within 2 days of ingesting cysts. o Transmission-Commonly found in pork. The cysts are in the muscle which if not heated high enough can be ingested. Pepsin in the stomach dissolves the cysts letting the larva out which move to the large intestine and migrate to the muscles. o Treatment-anti helminth drugs, once larva reach the muscle steroids are used to reduce inflammation. Eukaryotic diseases of the circulatory systems • Plasmodium spp.-Protozoa that causes malaria o Signs and symptoms-Symptoms start suddenly with chills and fever. Fever breaks with sweating followed by extreme fatigue, rapid, faint pulse, polyuria, headache, myalgia, nausea, and vomiting can also occur when the protozoa exit the blood cells. Organ failure can result due to lack of blood flow. o Transmission-Transferred through mosquito vector, rare in US. Lifecycle is partly in mosquitos and partly in human hosts. Undergoes antigenic variation. Attaches and invades red blood cells. o Treatment-sickle cell patients have resistance due to misshapen red blood cells. Antimalarial drugs are used for treatment but prevention is optimal since some forms have shown resistance to medication. • Toxoplasma gondii-Toxoplasmosis o Signs and symptoms-Sore lymph nodes and throat, swelling of spleen and liver. Infected people can have cysts lodge in tissues that can become reactivated if they are immunocompromised. o Transmission-domestic cats are main reservoirs, contact with cat or its feces can allow oocytes (eggs) to enter a host causing infection. In pregnancy, tachyzoites can cross the placenta and infect the fetus. This can lead to fetal loss or premature birth and can result in mental retardation, deafness or blindness. o Treatment-only needed for pregnant women and the immunocompromised. Prevention is preferred which is avoiding cats and their feces. • Trypanosoma cruzi- Chagas disease o Signs and symptoms-can be asymptomatic to life-threatening depending on the individual’s health condition. The acute phase includes fever, headache, muscle pain, rash, vomiting, diarrhea, enlarged spleen, liver, and lymph nodes. Swelling at the bite site is call chagoma. o Transmission-vector is triatomine bug (kissing bug) which bites around the mouth or eyes and deposits feces which can be rubbed in the bite/eyes. The protozoan then gets into the blood where it resided outside the blood cell. o Treatment-antiprotozoal drugs which are most effective in the acute phase of disease and less effective in the chronic phase. Prevention is preferred. • Leishmania spp.- Leishmaniasis o Signs and symptoms-Sore or nodule at bite site, can take months to years to develop and includes systemic infection with a fever, swollen lymph organs, and liver. Bone marrow infection can lead to anemia, leukopenia and thrombocytopenia. Can be fatal to those who are immunocompromised. o Transmission-humans, dogs, cats, horses, sheep and rodent are all reservoirs, passed by sand fly vector. o Treatment-antiprotozoal medication for serious cases, otherwise no treatment is necessary • Babesia spp.- Babesiosis o Signs and symptoms-most times asymptomatic, may experience malaise, fatigue, chills, fever, headache, muscle and joint pain. Can cause symptoms resembling malaria in the immunocompromised with jaundice, renal failure, and possibly death. Removal of the spleen can increase risk of symptoms. Uses red blood cells for replication. o Transmission-wild and domestic animals are reservoirs, ticks are vectors-transmission via tick bite. o Treatment-prevention by avoiding tick bites, antiprotozoal medication • Lymphatic filariasis- Elephantiasis o Signs and symptoms-most are asymptomatic but can cause swelling of the legs, breasts, or genitals o Transmission-Via mosquito bites; the adult worm live in the lymph and con produce small worms that in the blood where mosquitoes can pick them up through a bite. When they mosquito bites someone else, it transfers the small worms to a new host. o Treatment-aimed at reducing lymphedema and medication is used to kill the microscopic worms. The adult worms are hard to kill but treatment can prevent exposing someone else. They can live 5-7yrs and may eventually die but the lymphedema will remain. Eukaryotic diseases of the nervous system • Dinoflagellates- o Signs and symptoms-tingling in lips or tongue followed by tingling to finger and toes and then an inability to move the arms and legs. If respiratory muscles are affected death can occur from lack of oxygen. o Transmission-live in water, organism makes a neurotoxin. Toxin gets into the water where other shellfish absorb it. A person who consumes the seafood ingests the toxin as well. Produces neurotoxin saxitoxin. o Treatment-no treatment, toxin needs to be metabolized and worked through the body. If breathing is impacted respirators are needed to maintain airway. Prevention is key by watching to cases of algal bloom. • Acanthamoeba- o Signs and symptoms-typical of encephalitis which include headache, stiff neck, nausea, and vomiting, tiredness, confusion, lack of attention to people and surroundings, loss of balance and bodily control, seizures, and hallucinations. o Transmission-infection is rare and often associate with contact lens wearers. Commonly found in streams, ponds, or lakes. Can enter through the nasal cavity, or breaks in skin where it can travel to infect the brain or spinal cord or lungs. Once in the brain or spinal cord it can cause granulomatous amoebic encephalitis (GAE). o Treatment-possible with medication but work best if caught early or the infection is only of the skin. Once the pathogen reaches the CNS, they are almost always fatal. • Toxoplasma gondii- o Signs and symptoms-immunocompromised people are at risk for neurotoxoplasmosis when the pathogen enters the CNS from the blood and forms a brain abscess. The pathogen weakens the blood-brain barrier to gain entry to the brain by entering endothelial cells and reproducing causing the cells to burst. o Transmission- most mammals are reservoirs of this pathogen. Domestic cats are main reservoirs due to life cycle stages that can occur within them. Contact with cats or its feces can allow oocytes (eggs) to enter a host causing infection. o Treatment-multidrug approach and may last for several years to avoid reinfection. • Trypanosoma brucei-African sleeping sickness o Signs and symptoms-swollen cervical lymph nodes, an undulating fever that may last 3 days and subside for a week before returning o Transmission-passed through the bite of tsetse fly, animals are reservoirs, commonly found in domestic animals and humans. At the site of the bite, a chancre forms. The organism travels by circulatory system to become systemic. o Treatment-always fatal without treatment; early treatment is best and can use milder drugs. If 2nd stage is reached more powerful drugs can be used successfully. Follow up is necessary for years to ensure the pathogen does not return. Prevention of insect bites is the best preventative treatment.