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128 Cards in this Set
- Front
- Back
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Name a bacteria that colonizes in the nasal mucosa and respiratory tract and usually does not cause infection:
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Streptococcus pneumoniae
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This enteric bacteria eventually envades phagocytes in the spleen and liver. Name the bacteria and its associated disease.
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Salmonella typhi cause typhoid.
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This bacteria infects unpasteurized milk products and can live at low temperatures.
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Listeria monocytogenes
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Gram staining does not work in _______ (no cell wall), ______ (outer lipid interferes with stain), and ________ (very thin organism, very thin layer of peptidoglycan).
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Gram staining does not work in MYCOPLASMS (no cell wall) MYCOBACTERIA(outer lipid interferes with stain), and SPIROCHETES (very thin organism, very thin layer of peptidoglycan).
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Gram positive bacteria has a thicker cell wall than gram negative, and the gram negative has an outer membrane. What else distinguishes gram positive bacteria?
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the presence of teichoic and lipoteichoic acids
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The toxic properities of the lipopolysaccharide come from lipid ___.
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lipid A
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Flagella are represented as the ___ antigen.
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H
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What is the most conclusive means to make an evolutionary chart of bacteria?
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rRNA sequence determination
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T/F: Both Gram negative and gram positive bacteria are lysed by complement system.
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False. Gram negative are. Gram positive are not, but they can be tagged for phagocytosis.
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What bacteria can cause rheumatic fever?
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Group A streptococci
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What test distinguishes strep from staph?
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catalase test: staph is catalase positive
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Name two bacteria that try to kill its host in order to spread to a new organism.
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Virbrio cholera and Bacillus anthracis
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_______ cells cause antibody dependent cellular cytotoxicity.
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NK cells--they kill infected cells that present bacterial antigen bound by antibody
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Coagulase-negative staph is one of the most common causes of _________.
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bacteremia
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Catalase positive, coagulase positive bacteria:
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Staphylococcus Aureus
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If you have MRSA, which antibiotic will you try next?
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vancomycin
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Superantigens cause:
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Superantigens cause nonspecific cell activation. Community-acquired MRSA is a bug that has superantigens.
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An exotoxin-mediated syndrome that causes severe skin exfoliation
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Staphylococcal scalded skin syndrome
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A nocosomial infection caused by adherence to prosthetic devices (prosthetic joints, valves, IV lines)
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staphylococcus epidermidis
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a soft tissue skin infection with well demarcated borders
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erysipelas
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Cellulitis or erysipelas are associated with this bacteria, _________, and can lead to this Ab-mediated, nonsuppurative sequelae:
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Group A Strep; Acute Glomerulonephritis
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Group A strep is ______ sensitive.
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Bacitracin
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Name the Group B strep:
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Streptococcus agalactiae
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Group B strep is positive for the _______ test.
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CAMP test:
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The CAMP test demonstrates increased __________ in the interaction of two bacteria, ______ and _________.
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The CAMP test demonstrates increased HEMOLYSIS in the interaction of two bacteria, GROUP B STREP and STAPHYLOCOCCUS AUREUS.
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________ does not grow in presence of optochin and bile.
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Streptococcus pneumoniae
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Gram positive, diplococci:
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Streptococcus pneumoniae (Enterococci are short chains as well)
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A major virolence factor of S. pneumoniae is:
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its capsule
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This gram + cocci can live in bile and a high sodium environment:
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enterococci
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Enterococci is normal colon flora. Its most common clinical manifestation is:
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UTI
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In gram staining, how does the decolorizer (acetone ethanol) work?
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It removes the outer membrane in gram negative bacteria and the crystal violet complex can be released.
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Whenever lipid A is detected, you know you're dealing with gram ___ bacteria.
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negative
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Escherichia Coli characteristics:
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Gram negative. Part of normal flora. Part of Enterobacteriaceae group. Ferments lactose. Common nosocomial infection. Very common cause of UTI.
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If bacteria produces a red color on a MacConkey agar plate, then the bacteria can obviously....
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ferment lactose. The acid produced turns the plate red.
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Name three bacteria that can cause SECRETORY diarrhea by stimulating ________ in the gut, which leads to sodium absorption and chloride secretion malfunction.
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VIBRIO CHOLEARE, E. COLI, and BACILLUS CEREUS can cause secretory diarrhea by stimulating CYCLIC AMP in the gut, which leads to sodium absorption and chloride secretion malfunction.
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Bacillary dystenery is infection of the colon caused by this invasive bacteria ____________, leading to bloody diarrhea with mucus and pus.
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Shigella dysenteriae
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Typhoid fever is caused by: ___________. It's sequelae include:
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Salmonella typhi. Fever, abdominal pain, hepatoslenomegaly, rose spots on abdomen.
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Gram negative, capnophilic diplococci:
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Neisseria. Capnophilic bacteria like a high CO2 environment
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T/F: N. meningitidis can be normal flora whereas N. gonorrhoeae is not.
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True
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What is Waterhouse-Friderichsen Syndrome? Cause? Sequelae?
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hemorrhagic necrotic infarction of the adrenal glands caused by N. meningitidis resulting in hypotension and petechial rash
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The leading cause of bacterial meningitis in older children and young adults:
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N. meningitidis
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What is the most important virulence factor of N. meningitidis?
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The polysaccharide capsule. N. meningitidis has a capsule while N. gonorrhoease doesn't.
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These two STDs are frequently co-treated:
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N. gonorrhoeae and Chlamydia trachomatis
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Describe the Chlamydial cell cycle:
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Elementary body infects cells; reticulate body replicates
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Trachoma and lymphogranuloma venereum is caused by _________.
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Chlamydia trachomatis. Trachoma leads to blindness. Lymphogranuloma is a painless ulcer in genital area that causes lymphadenopathy and possibly elephantiasis of scrotum due to blocked lymph flow
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Name the two bacterial genera that produce spores. What distinguishes the two?
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Bacillus and Clostridium. Bacillus is aerobic or facultative anaerobe and Clostridium is anaerobic.
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Bacillus cereus main virulent factors are its:
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enterotoxins, one that causes vomiting and one that causes diarrhea
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What is an eschar?
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a big, black skin ulcer; caused by cutaneous anthrax
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A deadly enzootic infection known for its exotoxin.
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Bacillus anthracis
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Respiratory anthrax is almost always fatal. What are the three proteins in anthrax exotoxin?
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1) Protective Ag--binds to targeted cells to facilitate entry of the edema factor and lethal factor 2)edema factor--fluid accumlation 3) Lethal factor--kills cells, causes widespread necrosis of the lungs.
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What distinquishes Lysteria monocytogenes from other gram + bacteria?
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MOTILITY. Lysteria monocytogenes is a gram + rod, can live at low temperatures, and multiplies intracellularly in macrophages and epithelial cells
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Non-motile, aerobic/ facultative anaerobic, catalase and oxidase positive bacilli:
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Corynebacteria
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Mechanism of Action (MOA) of diptheria exotoxin:
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Disrupts protein synthesis: Interferes with elongation factor 2 which links AAs together to form peptides
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What is the genomic source of the exotoxin in Corynebacteria diphtheriae?
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the exotoxin is encoded by a bacteriophage
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Two acid-fast bacterial genera are:
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mycobacterium and nocardia
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This intracellular bacteria prevents fusion of phagolysosome via the cord factor:
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nocardia
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This organism, ________, causes a malabsorption syndrome, _________, affecting the small bowel. It can only be seen in a tissue culture.
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This organism, TROPHERYMA WHIPPELI, causes a malabsorption syndrome, WHIPPLE'S DISEASE, affecting the small bowel. It can only be seen in a tissue culture.
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The most common cause of nosocomial diarrhea:
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Clostridium difficile
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Two functions of MacConkey agar:
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Inhibits gram-positive bacterial growth and tells if the gram negative bacteria ferments lactose by the pink color produced on the agar
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The rapid coagulase latex test tests for ______.
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S. aureus: This tests identifies the presence of clumping factor (coagulase) and protein A in S. aureus.
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Salmonella produces _____ that creates a black precipate on XLD agar.
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H2S (Hydrogen sulfide)
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Gram negative coccobacilli include:
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Haemophilus and Bordetella
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Lysed blood agar is called:
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chocolate agar: Chololate agar is used to culture H. influenza, a non-hemolytic bacteria.
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What is the most important virulent factor of H. influenza?
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The type b antiphagocytic capsule. Also, lipopolysaccharide damages respiratory epithelium and IgA protease facillitates colonization by cleaving IgA
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Bordetella pertussis causes ______ via an exotoxin that destroys _________.
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Bordetella pertussis causes WHOOPING COUGH via an exotoxin that destroys CILIATED RESPIRATORY EPITHELIUM.
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What three exotoxin-mediated conditions are treated with one vaccine?
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Diptheria, acellular pertussis, and tetanus vaccine (DaPT)
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_________ causes point-source outbreaks of community-associated pneuomonias after growing in cooling towers or hospital water supplies.
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Legionella pneumophilia
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________ lack cell walls and are the smallest living organisms in terms of cell size and genome size.
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Mycoplasma
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What are the target cells of Rickettsia and Ehrlichia?
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Rickettsia target endothelial cells and Ehrlichia target WBCs.
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What organism causes Rocky Mountain Spotted Fever?
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Rickettsia rickettsii
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Small, gram-negative, obligate intracellular parasitie, vector-borne
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Rickettsia
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What is the classic triad in Rickettsial type disease?
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Fever, rash, and tick exposure history
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Rickettsia and Ehrlichia diseases are treated with _______.
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doxycycline
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What organism causes syphilis? What cell shape is it?
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Treponeme Pallidum; spirochete
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What is the most common bacterial STD?
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Chlamydiae trachomatis
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What is a structural distinguishing characteristic of mycobacteria?
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mycolic acids--they prevent gram staining
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_____ is often the first opportunistic infection that AIDS patients develop
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Tuberculosis
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A walled off granuloma exhibiting caseous necrosis with dystrophic calcification describes a ___________ which is found in patients suffering from __________.
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A walled off granuloma exhibiting caseous necrosis with dystrophic calcification describes a GHON COMPLEX which is found in patients suffering from REACTIVATION TB.
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What organism causes Hansen's disease?
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Mycobacterium leprae
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________ leprosy is non-progressive, has few organisms, demonstrates a cell-mediated response, and lives in the nerves of cooler parts of body. __________ leprosy does not demonstrate a good immune response, has a huge number of organisms, and is very infectious.
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TUBERCULOID leprosy is non-progressive, has few organisms, demonstrates a cell-mediated response, and lives in the nerves of cooler parts of body. LEPROMATOUS leprosy does not demonstrate a good immune response, has a huge number of organisms, and is very infectious.
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Name an example of microaerophilic bacteria:
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campylobacter
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Most pathogens are anaerobes/aerobes/facultative anaerobes.
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Facultative anaerobes
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Multiple morphological types of bacteria are seen in _______ infections.
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anaerobic
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This anaerobic, gram positive bacilli forms branching filamentous groups:
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Actinomyces israelii
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Draining sinuses containing "sulfur granules" are ________ colonies. What conditions does this bacteria cause?
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Actinomyces israelii: Dacryocystitis-a physical blockage of the tear duct; Actinomycosis-"Lumpy Jaw", an asymmetric oral infection
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Tetanus is caused by ________. What is the mechanism of the tetanus exotoxin?
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Clostridium tetani. The toxin, tetanospasmin, blocks inhibitory neurotransmitters (GABA and glycine), which leads to sustained muscle contraction- spastic paralysis.
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________ causes spastic paralysis while _______ causes flaccid paralysis.
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TETANUS toxin causes spastic paralysis while BOTULISM toxin causes flaccid paralysis.
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Botulism is caused by __________. What is the mechanism of the botulism toxin?
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Clostridium botulism. The toxin inhibits release of Ach from peripheral neuron resulting in flaccid paralysis.
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Untreated antibiotic-associated diarrhea can result in ___________ when _________ proliferates.
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Untreated antibiotic-associated diarrhea can result in PSEUDOMEMBRANOUS ENTEROCOLITIS when CLOSTRIDIUM DIFFICILE proliferates.
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What is the anatomical hallmark of anaerobic infections?
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abscesses
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Anaerobes are not susceptible to ________ antibiotics.
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aminoglycoside (penicillin resistance is common as well)
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Mobile genetic elements that can insert at random into DNA chromosomes or plasmids:
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transposons-these often encode antibody resistance genes and virulent factors
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Bacteria gene transfer is mediated by two properties:
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Cell-to-cell contact; DNase resistance
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Transduction is mediated by ________.
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a bacteriophage
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Conjugation requires _________.
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Cell-to-cell contact
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Transformation involves the uptake of ________, so it does not require ________, but is _________ sensitive.
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Transformation involves the uptake of FREE DNA, so it does not require CELL-TO-CELL CONTACT, but is DNase sensitive.
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The F-factor (F-plasmid) mediates __________ in gram negative bacteria.
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conjugation (In gram positive bacteria, conjugation is mediated by pheromones)
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The F-plasmid encodes a _____.
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pilus
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Antigenic drift results from ________ while antigenic shift results from ________.
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Antigenic drift results from SLOW ACCUMULATION OF POINT MUTATIONS while antigenic shift results from DNA RECOMBINATION.
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Name the four drugs used to treat Tuberculosis:
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Isoniazid, Rifampin, Ethambutol, and Pyrazinamide
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MOA of Isoniazid
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inhibits the biosynthesis of mycolic acids
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MOA of Rifampin
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inhibits RNA synthesis through inhibition of DNA-dependant RNA polymerase
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________ is used to treat tuberculosis and is activated at slightly acidic pH. It works in lysosomes inside macrophages.
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Pyrazinamide
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MOA of beta-lactamASE
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hydrolyzes the beta-lactum 4 member ring, thus inactivating the drug
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Beta-lactams demonstrate time dependent killing. What does this mean?
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Killing of bacteria is dependent on the proportion of time the drug concentration is above the Minimum Inhibitory Concentration
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Despite 60 years of use, all __________ and ___________ are still susceptible to penicillin G.
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Group A streptococci and Neisseria meningitides
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This drug is the most broadly active of all antibacterial drugs.
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Carbapenems
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This drug is a glycopeptide and interferes with cell wall synthesis by binding to transpeptidase.
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Vancomycin
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MOA of aminoglycosides
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bind to the 30s ribosomal subunit and interfere with protein synthesis
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30s ribosomal subunit inhibitors:
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aminoglycosides and tetracycline
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Can aminoglycosides treat CNS infections?
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No.
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Side effects of aminoglycosides:
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Nephrotoxicity and Ototoxicity
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MOA of quinolones
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inhibit DNA gyrase and topoisomerase IV
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This quinolone drug is effective (sometimes the drug of choice) against gram negative rods:
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ciprofloxacin
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_________ and __________ are co-administered to inhibit Folic Acid synthesis
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Sulfonamides and Trimethoprim
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This drug has good CNS penetration.
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Sulfonamide
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Hypersensitivity or allergic reactions are often seen in these two antibiotics, _______ and ________.
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Sulfonamides and penicillins
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The drug of choice for UTI:
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quinolones
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MOA of tetracycline:
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inhibits 30s RNA subunit
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Doxycycline is in what class of antibiotics? What is unique about doxycycline?
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Doxycycline is the only TETRACYCLINE that can be administered to patients with renal failure.
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Side effects of tetracycline:
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phototoxic skin reaction and teeth coloration
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MOA of macrolides
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binds to the 50s ribosomal subunit
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Name three macrolides:
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eyrthromycin, clarithromycin, and azithromycin
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MOA of clindamycin
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binds to the 50s ribosomal subunit
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Two classes of drugs that bind to the 50s ribosomal subunit
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macrolides and clindamycin
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Clindamycin is used to treat:
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gram negative anaerobes
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What is the number one side effect of clindamycin?
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Clostridium difficile colitis (or, pseudomembranous enterocolitis)
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Bacterial infections lead to _________ reactions mediated by __________. _________ handle viral infections. ___________ handle fungal infections. __________ handle parasitic infections.
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Bacterial infections lead to SUPPARITIVE reactions mediated by NEUTROPHILS. LYMPHOCYTES handle viral infections. MACROPHAGES handle fungal infections. EOSINOPHILS handle parasitic infections.
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