MMBio 221 Final Exam Guide Questions with Correct Answers Graded A 2024

Virulence: mycolic acid in cell wall causes slow growth, protection from lysis once bacteria are phagocytized, capacity for intracellular growth, resistance to Gram-staining, detergents, many antimicrobial drugs, and dessication - Mycobacterium Tuberculosis Unique properties: grows very slowly, can live within macrophages, tuberculin skin test--positive when red swelling appears, BCG vaccine is used in countries w/ lots of TB cases, effective on 80% of children and 20-50% of adults, cord factor that cause disease - Mycobacterium Tuberculosis Diseases: primary TB: initial infection, secondary TB: reactivation of TB after lying dormant for a period of time, disseminated TB: results when infection spreads throughout the body - Mycobacterium Tuberculosis Virulence: same as tuberculosis (mycobacterium) - Leprae unique properties: cannot be cultivated in cell free medium- cultured in footpads of mice and bellies of 9-banded armadillos; transmission via person to person contact or through break in skin; some protection provided by BCG vaccine; treated with dapsone and rifampin as well as clofazimine - Leprae DISEASES- 1. Tuberculoid Leprosy: high cell mediated response and low antibody, nonprogressive disease characterized by loss of sensation in skin regions, shallow skin lesions and only occasional mutilation of body. 2. Lepromatous Leprosy: low cell-mediated response and high antibody, produces gradual tissue destruction resulting in loss of facial features, digits, and other body parts, numerous deep skin lesions and nodules appear, common to have mutilated extremities - Leprae VIRULENCE- has mycolic acid since it's a mycobacterium (see tuberculosis), produces mycolactone: polyketide toxin that destroys subcutaneous tissue (top skin later dies and sloughs off), powerful immune suppressing agent - Ulcerans UNIQUE PROPERTIES- 1. associated with slow moving water, 2. enters skin through abrasions, 3. grows extracellularly, 4. no proven therapy so ulcer is excised and skin grafts are used - Ulcerans DISEASES- 1. Beruli Ulcer (see above for symptoms/treatment) - Ulcerans UNIQUE PROPERTIES- 1. small, Gram-positive rods found on skin, 2. opportunistic pathogen, 3. treated w/ antimicrobial drugs, 4. most common species involved in human infections - Propionibacterium acnes DISEASES- acne: bacteria infect a hair follicle, causing accumulation of colonizing bac, and sebum - Propionibacterium acnes 3 types of antigens that are used to serotype enteric bacteria - Antigen O - polysaccharide Antigen K - protein and polysaccharide capsular antigens Antigen H - flagellar proteins rapidly ferment lactose part of general microbiota may be opportunistic pathogens - Coliform DISEASES - Brucellosis - transmitted to humans in unpasteurized contaminated milk or contact with animal blood, urine, placentas. Humans: causes fluctuating fever (AKA undulant fever, bang's fever, malta fever, rock fever of Gibraltar, fever of Crete) - chills, sweating, headache, weight loss. Animals: STDs and abortive disease due to viscerotropism for reproductive organs. generally asymptomatic or mild, but can cause sterility & abortion. - Brucella melitensis VIRULENCE - attaches to ciliated epithelial cells through 2 adhesions (filamentous hemagglutinin and perussis toxin) produces 4 toxins: pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, tracheal cytotoxin - Bordetella pertussis UNIQUE PROPERTIES - bacteria inhaled in aerosols. causes pediatric disease Pertussis. - Bordetella pertussis DISEASES - Pertussis (whooping cough) - occurs when ciliated epithelial cells of trachea are damaged. - Bordetella pertussis UNIQUE PROPERTIES- normal microbiota of intestinal & upper respiratory tract, constitutes just 1% of the bacteria in the colon, metronidazole treats it, involved in 85% of all gastrointestinal disease and 5% of all bacteremias - Bacteroides fragilis DISEASES- 1. abdominal infections: bacteria that infects following ruptured appendix, 2. genital infections in women, 3. wound infections on the skin - Bacteroides fragilis VIRULENCE- spirochetes continually change their antigenic surface components = body can't get rid of it w/ memory B cells - Borrelia recurrentis DISEASES- 1. epidemic relapsing fever: transmitted to humans by the human body louse, 2. endemic relapsing fever: transmitted to humans by soft ticks -both diseases result in 4-10 episodes of fever and septicemia separated by symptom-free intervals - Borrelia recurrentis