front 1 The most frequently used portal of entry for pathogens is the | back 1 mucous membranes of the respiratory tract. |
front 2 The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the host's antibodies is called | back 2 antigenic variation. |
front 3 The ID50 is | back 3 the dose that will cause an infection in 50 percent of the test population. |
front 4 All of the following contribute to a pathogen's invasiveness EXCEPT | back 4 toxins. |
front 5 Most pathogens that gain access through the skin | back 5 enter through hair follicles and sweat ducts. |
front 6 Which of the following statements is FALSE? | back 6 Coagulase destroys blood clots. |
front 7 Which of the following statements about exotoxins is generally FALSE? | back 7 They are resistant to heat. |
front 8 Endotoxins are | back 8 part of the gram-negative cell wall. |
front 9 Which of the following is NOT a membrane-disrupting toxin? | back 9 A-B toxin |
front 10 Cytopathic effects are changes in host cells due to | back 10 viral infections |
front 11 Which disease-associated fungi or fungal characteristics are mismatched? | back 11 Claviceps purpura - aflatoxin |
front 12 All of the following are methods of avoiding host antibodies EXCEPT | back 12 membrane-disrupting toxins. |
front 13 Siderophores are bacterial proteins that compete with the host's | back 13 iron-transport proteins. |
front 14 The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of | back 14 adhesins and ligands. |
front 15 All of the following are examples of entry via the parenteral route EXCEPT | back 15 hair follicle. |
front 16 Superantigens produce intense immune responses by stimulating lymphocytes to produce | back 16 cytokines. |
front 17 Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by | back 17 boiling food prior to consumption. |
front 18 All of the following organisms produce exotoxins EXCEPT | back 18 Salmonella typhi. |
front 19 Which of the following cytopathic effects is cytocidal? | back 19 release of enzymes from lysosomes |
front 20 All of the following are used by bacteria to attach to host cells EXCEPT | back 20 A-B toxins. |
front 21 Symptoms of protozoan and helminthic diseases are due to | back 21 tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues. |
front 22 Which of the following statements about staphylococcal enterotoxin is FALSE? | back 22 It is produced by Staphylococcus aureus growing in the host's intestines. |
front 23 Which of the following contributes to the virulence of a pathogen? | back 23 numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production |
front 24 Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages | back 24 give new gene sequences to the host bacteria. |
front 25 Twenty-five people developed symptoms of nausea, vomiting, and diarrhea three to six hours after attending a church picnic where they ate a ham and green bean casserole with cream sauce. The most likely cause of this case of food intoxication is | back 25 staphylococcal enterotoxin. |
front 26 Which of the following statements about M protein is FALSE? | back 26 It is readily digested by phagocytes. |
front 27 Symptoms of intense inflammation and shock occur in some gram-positive bacterial infections due to | back 27 superantigens. |
front 28 Which of the following is an example of direct damage due to bacterial infection? | back 28 the invasion and lysis of intestinal cells by E. coli |
front 29 Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use? | back 29 mucous membranes only |
front 30 All of the following bacteria release endotoxin EXCEPT | back 30 Clostridium botulinum. |
front 31 Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed, | back 31 polypeptide B would not be able to enter the cells. |
front 32 Bacteria such as E. coli and Salmonella produce invasins that bind host cells, thus causing the cells to | back 32 engulf the bacteria. |
front 33 Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? | back 33 inducing TNF |
front 34 Injectable drugs are tested for endotoxins by | back 34 the Limulus amoebocyte lysate test. |
front 35 Endotoxins in sterile injectable drugs could cause | back 35 septic shock symptoms. |
front 36 Gram-negative septic shock results from the following events. What is the second step? | back 36 LPS is released from gram-negative bacteria. |
front 37 Antibiotics can lead to septic shock if used to treat | back 37 gram-negative bacterial infections |
front 38 Which of the following is NOT a cytopathic effect of viruses? | back 38 toxin production |
front 39 Table 15.1 Staphylococcus aureus Wound <10 Staphylococcus aureus Wound + Ampicillin 300 | back 39 decreases the risk of staphylococcal infection |
front 40 Table 15.2 E. coli O157:H7 20 Legionella pneumophila 1 Shigella 10 Treponema pallidum 57 Which organism in Table 15.2 most easily causes an infection? | back 40 Legionella pneumophila |
front 41 Table 15.2 E. coli O157:H7 20 Legionella pneumophila 1 Shigella 10 Treponema pallidum 57 Which organism in Table 15.2 causes the most severe disease? | back 41 It cannot be determined from the information provided. |
front 42 Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that | back 42 streptococcal colonization is necessary for periodontal disease. |
front 43 Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by | back 43 lysogenic conversion. |
front 44 In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes | back 44 a decrease in blood pressure. |
front 45 Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to | back 45 endotoxin. |
front 46 The best description of direct damage by a pathogen is | back 46 host cells destroyed when pathogens metabolize and multiply. |
front 47 Which is NOT specifically employed by pathogens to avoid destruction by phagocytosis? | back 47 producing superantigens |
front 48 A retired contract administrator who enjoyed gardening sought medical attention for what appeared to be a sinus infection. He received antimicrobials but the conditioned worsened and he was experiencing severe painful spasms in his jaw. He admitted to injuring himself with a gardening tool while wearing sandals in the yard but did not seek medical attention for the wound. The man is likely experiencing | back 48 intoxication caused by a focal C. tetani infection. |
front 49 For what reason might the ID50 for Salmonella Typhi decrease when a rat simultaneously ingests sulfa drugs with the pathogen? | back 49 The antimicrobial interferes with the microbiome enabling the pathogen to more easily establish infection. |
front 50 Which pathogen and virulence factor are mismatched? | back 50 Shigella sonnei - coagulase |