BIOL 2420 Exam 4 Study Guide Fall 2024 PDF

Biology 2420 Study Guide – Exam 4 – Fall 2024 For all chapters: 1. Be able to match the organisms to the diseases for not only this chapter, but all of these. 2. Know the important key points on diseases, such as main effects, route of infection, disease vector. 3....

Biology 2420 Study Guide – Exam 4 – Fall 2024 For all chapters: 1. Be able to match the organisms to the diseases for not only this chapter, but all of these. 2. Know the important key points on diseases, such as main effects, route of infection, disease vector. 3. Chapter 20 – Gram Negative Cocci & Bacilli 1. What diseases are associated w/ Neisseria? (Slide 5) a. Gonorrhea and meningitis 2. What are the characteristics of these diseases? a. Gonorrhea: secrete protease that cleaves secretory immunoglobulin A (IgA) i. Survive within neutrophils ii. Antigenic variability iii. Opa proteins bind to T cell receptors, preventing activation and immunological memory b. Meningitis: normal microbiota of the upper respiratory tract 3. What is the morphology of Neisseria? (6) a. Diplococcus 4. Gonorrhea – transmission, treatment, effect on infants (7-11)] a. Transmission: sexual encounters b. Treatment: complicated due to resistant strains; broad-spectrum intramuscular cephalosporins c. Effect on infants: ophthalmia neonatorum – infant blindness due to a gonorrheal infection of the eyes 5. Who is affected by Neisseria Meningitidis? a. Individuals under the age of 20 6. Prevention? a. Vaccination protects against serogroups A, C, Y, and W but not B due to similarities with neurons 7. What are the 3 most common causes of gram-negative Hospital acquired infections in the US? (20) a. Escherichia b. Proteus c. Pseudomonas 8. Are most of these organisms true pathogens or opportunistic? (22) a. Enteric bacteria are the most common gram-negative pathogens of humans, mostly opportunistic 9. What are some of the tests for identifying these? (24) a. 10. What do the O and H refer to when looking at strains of E. coli? (25) a. O polysaccharide on surface 1  b. H antigen on flagella c. Antigens used for identification (Escherichia coli O157:H7) 11. What are the virulence factors that are common to these? (25) a. Capsules, fimbrae, adhesisns, exotoxins, siderophores, hemolysins, type III secretion system injects material into host cells 12. What is MacConkey good for? Is it a differential media? (28) a. For gram negatives; good for seeing growth b. It is differential and selective growth 13. What is a coliform? Are they all pathogens? Why do we care about them? (31) a. Coliform (indicator organisms): rapidly ferment lactose; normal microbiota but may be opportunistic pathogens b. Coliforms in water indicate impure water and poor sewage treatment 14. Are all E. coli pathogens? What is so special about O157:H7? (33) a. Not all E. coli are pathogens, they are part of the normal microbiota of the intestine b. O157:H7 – most prevalent pathogenic E. coli; Shiga-like toxin 15. What are some gram – true pathogens? (35) a. Salmonella, Shigella, and Yersinia 16. Most common causes of Salmonella? (36) a. Most human infections due to consuming food contaminated with animal feces b. Poultry and eggs 17. What organism is associated with Typhoid fever? (39) a. Salmonella 18. How serious is Shigella? How is it transmitted? And treated? (42, 44) a. Severe form of dysentery – pus and bloody stool b. Associated with poor hygiene and sewage treatment c. People ingest bacteria present on their own contaminated hands or in contaminated food; person-to-person spread is possible d. Treated with fluid and electrolyte replacement 19. Two types of disease caused by Yersinia? Which is worse? (45) a. Bubonic plague (50% death untreated) and pneumonic plague (near 100% fatality) 20. How would you typically catch this disease? (45) a. Y. pestis b. Xenopsylla cheopis (rat flea) after biofilm blockage c. Uses type III secretion system to inject apoptosis protein in macrophages and neurophils 21. What diseases do Pasteurellacea cause? Symptoms? Who is usually affected? (49-52) a. Haemophilus influenzae b. Symptoms: stiff neck, light sensitivity, and seizures c. Common cause of meningitis prior to vaccination (3-28 months old) 22. What disease does Bordetella cause? How is it contacted, prevented? (54-57) a. Causes pertussis (whooping cough) – B. pertussis b. Contracted by inhalation: bacteria inhaled in aerosols multiply in ciliated cells c. Prevented by DTaP vaccine 23. What is the reservoir for Pseudomonas? True pathogen or opportunist? Treatment? (60) a. Reservoir: ubiquitous in soil, decaying organic matter, and moist environments b. Opportunistic infections in immunocompromised patients (can colonize almost any organ or system, burn victims) c. Treatment: difficult due to drug resistance 2 24. What is unique/unusual about risk factors for Prevotella? (64) a. Vegetarians; associated with a healthy diet high in plants b. Sinus and ear infections c. Almost all periodontal infections d. Gynecological infections e. Brain abscesses f. Abdominal infections g. Treat by surgical removal of infected tissue and carbapenem Chapter 21 – Intracellular Bacteria 1. What diseases did we discuss caused by Rickettsia? (3-16) a. R. rickettsii: rocky mountain spotted fever b. R. prowazekii: epidemic typhus c. R. typhi: murine typhus 2. How is each contracted? What is the vector? (3-16) a. R. rickettsii: spread by wood tickets and dog ticks with transovarian passage b. R. prowazekii: human body louse transmits bacteria to humans through its feces c. R. typhi: rat flea and cat flea 3. What regions of the country are most affected by RMSF? (7) a. Montana, Iowa, Missouri, Tennessee, North Carolina, Virginia 4. What disease is transmitted by the body louse? (12) a. Rickettsia prowazekii – epidemic typhus b. Pediculus humanis 5. What cells of the body does Ehrlichia reproduce in and inhabit? (14) a. Leukocytes (WBCs) 6. Which of these diseases are a problem in Texas? (3-16) a. RMSF, Ehrlichiosis, and anaplasmosis 7. STD that is also a leading cause of blindness and sterility (20-28) a. Chlamydia trachomatis 8. Causative organism of syphilis (31-32) a. Treponema pallidum pallidum 9. Characteristics, cause, vector, organism, incidence for Lyme disease (42-47) a. Borrelia burgdorferi is the causative agent i. Lacks iron-containing enzymes and proteins and uses manganese to avoid the lack of iron in body b. Bacteria are transmitted to humans via a tick bite i. Hard ticks of the genus lxodes are the vectors c. Three phases of disease – i. Expanding red “bull’s-eye” rash occurs at infection site ii. Neurological symptoms and cardiac dysfunction (meningitis, encephalitis, etc) iii. Severe arthritis that can last for years (result of the body’s immune response) d. Increase of cases in the U.S. (humans in closer association with Borrelia-infected deer ticks) 3  Chapter 22 – Fungal pathogens 1. Know the characteristics of the major conditions and diseases such as dermatophytes, Candidiasis, Coccidioides , and Pneumocystis jirovici 2. Why are mycoses difficult to diagnose and treat? (3) a. Signs of mycoses are often missed or misinterpreted b. Fungi are often resistant to antifungal agents 3. What are 3 ways that fungi are pathogenic? (4) a. Fungal infections: most common mycoses; caused by presence of true pathogens or opportunists b. Fungal toxicoses: acquired through ingestion; occur when poisonous mushrooms are eaten c. Allergies: most often result from inhalation of fungal spores 4. What is the “go to” drug for Fungal infections? (5) a. Amphotericin B 5. Pathogenesis and symptoms of the main systemic mycoses (6- 24) a. Histoplasma i. Usually asymptomatic and resolves without damage ii. Most infections occur through inhalation of spores iii. H. capsulatum is phagocytized by macrophages in the lungs (disperse the fungi beyond the lungs via the blood and lymph) b. Blastomyces i. Bastomyces dermatitidis is the causative agent (moist soil and decaying leaves) ii. Symptoms are nonspecific (muscle aches, fever, chills, etc) c. Coccidiodes i. Coccidiodes immitis is the causative agent ii. Fungi in desert soil, rodent burrows, archeological remains, mines iii. Most often result in pulmonary conditions; dissemination to other sites occurs most in immunocompromised 6. Pneumocystis pneumonia – what type of infection is it? Who is affected by it? (26) a. Common opportunistic fungal infection of AIDS patients b. Majority of individuals exposed to P. jiroveci by age 5 7. Candidiasis – How is it contacted? What areas of the body are typically affected? (29) a. One of the few fungi transmitted between individuals b. Common microbiota of the skin and mucous membranes c. Thrush- oral candiasis d. Yeast infection: vaginal candidiasis 8. Effect of fungal infections in immune compromised individuals. (35) a. Permanent immune dysfunction makes cure of infections unlikely i. Mycoses account for most deaths associated with AIDS 9. What is ringworm? (36) a. Dermatophytosis: infections of the skin, nails, or hair caused by dermatophytes b. Can be spread from person to person Chapter 23 – Protozoans 1. Amoebae 4  a. What is the name of the organism? i. Entamoeba histolytica ii. Naegleria flowleri b. What is the route of infection? i. Entamoeba – ingestion; infection most commonly occurs by drinking contaminated water ii. Naegleria fowleri – inhalation; infection occurs when swimmers inhale contaminated water c. Signs and symptoms? i. Entamoeba histolytica carried asymptomatically in the digestive tracts of humans 1. Invasive amebic dysentery: severe diarrhea, colitis, appendicitis, and ulceration of the intestinal mucosa d. Prognosis? i. Entamoeba: amebic dysentery and invasive extraintestinal amebiasis can be fatal ii. Naegleria fowleri: causes hemorrhage, coma, and usually death within 10 days;– death e. Vector? i. Entamoeba: water ii. Naegleria fowleri: protozoan infects the nasal mucosa from swimming water, penetrates the brain, and feeds on brain tissues; contaminated water f. Anything really creepy? i. Entamoeba: Few cause disease; Excystment occurs in the small intestine; Trophozoites migrate to the large intestine ii. Naegleria fowleri: 2006-2015 – 37 infections 2. Flagellates – Trypanasoma cruzi a. What is the name of the organism? i. Trypanosoma cruzi – Chagas’ disease b. What is the route of infection? i. Bites – bit of insects in genus Triatoma c. Signs and symptoms? i. Acute stage characterized by chagomas (swelling at bites) ii. Generalized stage with fever, swollen lymph nodes, myocarditis, and enlargement of spleen, esophagus, and colon iii. An asymptomatic chronic stage iv. Symptomatic stage characterized by congestive heart failure following formation of pseudocysts d. Prognosis? i. Parasite-induced heart disease is a leading cause of death in Latin America e. Vector? i. Triatoma insects ii. Primary reservoirs: opossums and armadillos f. Anything really creepy? i. “Kissing bugs” feed preferentially from blood vessels in the lips 3. Flagellates – Trypanosoma brucei gambiense (African sleeping sickness) a. What is the name of the organism? i. Trypanosoma brucei gambiense b. What is the route of infection? i. Bite – fly bite becomes a lesion with dead tissue 5  c. Signs and symptoms i. Parasites in the blood trigger fever, lymph node swelling, and headaches ii. Meningoencephalitis d. Prognosis? i. Death in months e. Vector? i. Tsetse fly f. Anything really creepy? i. Antigenic variation makes vaccine difficult (100 varieties) ii. T. brucei matures in the salivary gland of the tsetse fly; tsetse flies directly inject T. brucei; T. brucei live outside hosts’ cells 4. Flagellates – Leishmania a. What is the name of the organism? i. Leishmania b. What is the route of infection? i. Originates from a bite c. Signs and symptoms? i. Cutaneous leishmaniasis: large painless skin ulcers form at the bite wounds ii. Mucocutaneous leishmaniasis: skin lesions enlarge to encompass mucous membranes of the mouth, nose, or soft plate iii. Visceral leishmaniasis: macrophages carry the parasite to the liver, spleen, bone marrow, and lymph nodes d. Prognosis? i. Fatal in 95% of untreated cases of visceral e. Vector? i. Phlebotomus or Lutzomyia (sand fly) f. Anything really creepy? i. 5. Apicomplexan – Giardia a. What is the name of the organism? i. Giardia intestinalis – causes giardiasis b. What is the route of infection? i. Ingestion – ingest cysts in contaminated food, water, or hands c. Signs and symptoms? i. Diarrhea, pain, bloating, nausea, vomiting, and fever d. Prognosis? i. Ranges from asymptomatic infection to gastrointestinal disease e. Vector? i. Beavers are a common reservoir ii. Cyst from food, water, or hands f. Anything really creepy? i. Hydrogen sulfide detected in the breath or stools 6. Apicomplexan – Trichomonas a. What is the name of the organism? i. Trichomonas vaginalis b. What is the route of infection? i. Sexual encounters 6  c. Signs and symptoms? i. Women: vaginosis – causes odorous discharge, vaginal and cervical lesions, abdominal pain, and painful urination and intercourse d. Prognosis? i. Treated with nitroimidazole drugs ii. Vaginosis in women iii. Asymptomatic in men e. Vector? i. Humans f. Anything really creepy? i. Most common protozoan causing disease in industrialized nations 7. Apicomplexans – Plasmodium (causes malaria) a. What is the name of the organism? i. Plasmodium vivax ii. Plasmodium falciparum b. What is the route of infection? i. Bite from anopheles’ mosquito c. Signs and symptoms? i. Plasmodium vivax: mildest and most prevalent form; dormant in the liver; fever every 2 days ii. Plasmodium ovale and Plasmodium malariae: benign; restricted geographically iii. Plasmodium falciparum: (most deadly); severe anemia; 50% morality; blood cells develop knobs that block capillaries; affects the kidneys, liver, and brain; black urine is characteristic d. Prognosis? i. P. falciparum: death of brain tissue can be fatal within 24 hours e. Vector? i. Anopheles’ mosquito f. Anything really creepy? i. Black urine 8. Apicomplexans – Toxoplasma a. What is the name of the organism? i. Toxoplasma – T. gondii is the causative agent of toxoplasmosis b. What is the route of infection? i. Infection due to consumption of undercooked meat containing the parasite ii. Ingestion or inhalation of contaminated soil can also occur iii. Cats are definitive host c. Signs and symptoms? i. May alter human behavior – infected men tend to be introverted, suspicious and rebellious, whereas infected women tend to be extraverted, trusting and obedient d. Prognosis? i. Chronic condition by forming cyst with bradyzoites e. Vector? i. Cat fluids f. Anything really creepy? i. Most severe in AIDS patients and fetuses 7  ii. Transplacental transfer of the protozoan can cause abortion, stillbirth, and various birth defects 9. Helminths – Cestodes a. What is the name of the organism? i. Cestodes – tapeworms b. What is the route of infection? i. Ingestion: uncooked meat c. Signs and symptoms? i. Taenia Solium is pork tapeworm can cause cystercosis (encystment in various tissues) d. Prognosis? i. Most individuals shed strobila without having symptoms, intestinal blockage can occur e. Vector? i. Cattle and swine serve as intermediate hosts f. Anything really creepy? i. Diphyllobthrium latum (fish tapeworm) – largest at 3 ft, makes millions of eggs/day, shrimp in intermediate host 10. Trematodes – Fasciola hepatica a. What is the name of the organism? i. Fasciola hepatica b. What is the route of infection? i. F. hepatica —Ingestion: metacercariae from aquatic vegetation c. Signs and symptoms? i. Fasciola hepatica – symptoms coincide with episodes of bile duct obstruction and inflammation d. Prognosis? i. Chronic infection occur when flukes reside in bile duct e. Vector? i. Reservoir in water plants, vectors are the humans, sheep and cattle that consume them f. Anything really creepy? i. Humans are the accidental definitive hosts 11. Trematodes – Schistosoma a. What is the name of the organism? i. Schistosoma – causative agent is schistosomiasis b. What is the route of infection? i. Cercariae burrow through skin of humans who contact contaminated water c. Signs and symptoms? i. Dermatitis may occur at the site where cercariae entered ii. Swimmer’s itch may develop at the site of cercariae entry d. Prognosis? i. Infections can become chronic and can be fatal when eggs calcify in tissues to become granulomas e. Vector? i. Cercariae ii. Humans are the principal definitive host f. Anything really creepy? i. 8 12. Nemotodes – Ascaris lumbricoides a. What is the name of the organism? i. Ascaris lumbricoides – roundworm; usually unnoticed until blocks intestines b. What is the route of infection? i. c. Signs and symptoms? i. Intestinal blockage; abdominal pain, nausea, vomiting, and intestinal obstruction if the worm burden is high d. Prognosis? i. e. Vector? i. f. Anything really creepy? i. Most common nematode infection of humans worldwide 13. Nematodes – Enterobius vermicularis a. What is the name of the organism? i. Enterobius vermicularis – pinworms, usually asymptomatic, highly infectious b. What is the route of infection? i. Female pinworms deposit their eggs in the anus c. Signs and symptoms? i. Can be asymptomatic ii. Intense perianal itching occurs if symptomatic d. Prognosis? i. e. Vector? i. f. Anything really creepy? i. Most common parasitic worm found in the U.S. 14. Nematodes – Ancylostoma duodenale a. What is the name of the organism? i. Ancylostoma duodenale – hookworm, attaches to intestine and causes anemia b. What is the route of infection? i. Enters through feet ii. Larvae in soil burrow through skin c. Signs and symptoms? i. Anemia, lethargic behavior, and craving for peculiar foods (pica) d. Prognosis? i. e. Vector? i. Eggs hatch on ground, releasing larvae. Larvae enter through the soles of the feet and travel to the lungs. Ascend into throat to be swallowed f. Anything really creepy? i. 15. Nematodes – Trichinella spiralis (trichinellosis) a. What is the name of the organism? i. Trichinella spiralis (trichinellosis) – forms cysts in muscle tissue b. What is the route of infection? 9  i. Encysted larvae are ingested from undercooked pork and other meats c. Signs and symptoms? i. Fever, eye swelling, gastrointestinal upset d. Prognosis? i. e. Vector? i. Digestion removes the cyst wall and the worm matures into an adult ii. Adults produce larvae in the intestines that invade tissues and form new cysts f. Anything really creepy? i. Chapter 24 – DNA Viruses 1. What is Reyes’ syndrome? What is it linked to? a. Flu and chickenpox; use of aspirin; causes massive inflammation throughout the body and damage to liver and swelling in the brain 2. What are the parts of the virus made of (Capsid, envelope, Nucleic acid) (7) a. 3. Smallpox / Variola major (7) a. Causes severe disease with a 20% mortality rate 4. Reasons that Smallpox was able to be eradicated (9) a. Inexpensive, stable, and effective vaccine b. No animal reservoirs c. Obvious symptoms allow for quick diagnosis and quarantine d. Lack of asymptomatic cases e. Virus is only spread via close contact 5. Human Herpes viruses – diseases they cause, how transmitted a. HHV-1: cold sores (spread by close contact) b. HHV-2: genital herpes (spread by sexual intercourse) 6. Mononucleosis characteristics, other diseases it may be associated with (27) a. Asymptomatic in children—fever, sore throat, swollen lymph nodes in neck, fatigue, enlarged spleen b. 95% of adults have antibodies, 20% secrete orally c. Replicates in resting memory B cells d. Form unusual lobed nuclei (mononucleosis) e. Produce heterophile antibodies (generalized immunity) f. May be involved in multiple sclerosis, Hodgkin’s lymphoma, and nasopharyngeal cancer 7. Adenoviruses diseases (38) a. One of the many causative agents of the common cold b. Respiratory infections – viruses taken into cells lining the respiratory tract via endocytosis; causes sneezing, sore throat, cough, headache, and malaise c. Attenuated vaccine is available only for military personnel 8. Hepadnaviruses – diseases (42) a. Enveloped DNA viruses b. Hepatitis B virus (HBV) 10  Chapter 25 – RNA Viruses 1. What are the diseases associated with Rhinoviruses? How contracted? Immunity? (7) a. Causes most cases of the cold; infections limited to the upper respiratory tract b. Transmitted by aerosols, fomites, or hand-to-hand contact i. Most commonly transmitted by direct person-to-person contact c. People acquire some immunity against serotypes that have infected them (the number of infections tend to decrease with age) 2. How is polio transmitted? (8) a. Person-to-person contact or by contaminated food and water 3. Difference between the two vaccines? Why is one preferred? (13) a. Inactivated polio vaccine (IPV): is effective and inexpensive; is stable during transport/storage; poses no risk of vaccine-related disease b. Oral polio vaccine (OPV): induces secretory antibody response similar to natural infection; is easy to administer; can result in herd immunity 4. What is postpolio syndrome? (13) a. Crippling deterioration in the function of polio-affected muscles 5. Characteristics of Dengue Fever (20) a. Flavivirus transmitted by Aedes mosquitoes b. Initially causes fever, weakness, edema, and severe pain c. Second phase causes bright rash and return of fever d. Dengue hemorrhagic fever can occur following reinfection (causes internal bleeding, shock, and possibly death) e. No treatment is available 6. Yellow fever a. Vector: aedes mosquitoes b. Natural hosts: monkeys, humans c. Symptoms: hepatitis, hemorrhagic fever, shock 7. Rubella, mumps, etc a. Rubella: infection begins in the respiratory system but spreads throughout the body i. Characterized by a rash of flat, pink to red spots ii. Infections in children are usually not serious iii. Adults can develop arthritis/encephalitis iv. Infection of pregnant women can cause congenital defects (blindness, deafness, mental retardation, microencephaly) v. Vaccination effective at reducing the incidence of rubella b. Mumps: viruses infect upper respiratory system and spread to other organs i. Transmission occurs via respiratory secretions ii. Parotitis results – painful enlargement of the parotid salivary glands iii. Orchitis, meningitis, pancreatitis, or deafness in one ear can occur; infection may also be asymptomatic iv. Recovery is typically complete v. No specific treatment is available vi. Vaccine has almost eradicated mumps in the industrialized world c. Measles: spread in the air via respiratory droplets; viruses infect the respiratory tract, then spread throughout body i. Koplik’s spots appear on the mucous membrane of the mouth 11  ii. Lesions then appear on the head and spread over the body iii. Rare complications result pneumonia, encephalitis, and subacute sclerosing pancephalitis (SSPE) iv. Vaccine has eliminated endemic measles in the U.S. (measles cases have recently reemerged) 8. Rubella, Marburg incidence, hosts, description. (61-65) a. Hemorrhagic fevers: Marburg virus and Ebola virus are the causative agents b. Natural reservoir is thought to be fruit bats c. Initial mode of transmission to humans is unknown d. Spread person to person by contaminated body fluids 9. Influenza – (68-72) a. Signs and symptoms: fever, malaise, headache, and myalgia b. Pathogenesis: enters the body via respiratory route (incubation period is about one day) c. Treatment: oseltamivir or zanamivir inhibit type A or type B neuraminidase d. Prevention: immunization with multivalent vaccines; protect only against the strains included in the vaccine 12