front 1 The most frequently used portal of entry for pathogens is the | back 1 c. mucous membranes of the gastrointestinal 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 e. antigenic variation. |
front 3 Most pathogens that gain access through the skin | back 3 a. enter through hair follicles and sweat ducts. |
front 4 The ID50 is | back 4 c. the dose that will cause an infection in 50 percent of the test population. |
front 5 All of the following contribute to a pathogen's invasiveness EXCEPT | back 5 d. toxins. |
front 6 Which of the following statements is FALSE? | back 6 a.Coagulase destroys blood clots. |
front 7 Which of the following statements about exotoxins is generally FALSE? | back 7 e.They are resistant to heat. |
front 8 Endotoxins are | back 8 d.part of the gram-negative cell wall. |
front 9 Which of the following is NOT a membrane-disrupting toxin? | back 9 a.A-B toxin |
front 10 Cytopathic effects are changes in host cells due to | back 10 d.viral infections. |
front 11 Which disease-associated fungi or fungal characteristics are mismatched? | back 11 d.Claviceps purpura - aflatoxin |
front 12 All of the following are methods of avoiding host antibodies EXCEPT | back 12 a.membrane-disrupting toxins. |
front 13 Siderophores are bacterial proteins that compete with the host's | back 13 b.iron-transport proteins. |
front 14 The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of | back 14 a.adhesins and ligands. |
front 15 All of the following are examples of entry via the parenteral route EXCEPT | back 15 a.hair follicle. |
front 16 Superantigens produce intense immune responses by stimulating lymphocytes to produce | back 16 b.cytokines. |
front 17 Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by | back 17 e.boiling food prior to consumption. |
front 18 All of the following organisms produce exotoxins EXCEPT | back 18 e.Salmonella typhi. |
front 19 Which of the following cytopathic effects is cytocidal? | back 19 c.release of enzymes from lysosomes |
front 20 All of the following are used by bacteria to attach to host cells EXCEPT | back 20 e.A-B toxins. |
front 21 Symptoms of protozoan and helminthic diseases are due to | back 21 b.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 c.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 c.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 a.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 c.staphylococcal enterotoxin. |
front 26 Which of the following statements about M protein is FALSE? | back 26 a.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 b.superantigens. |
front 28 Which of the following is an example of direct damage due to bacterial infection? | back 28 c.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 d.mucous membranes only |
front 30 All of the following bacteria release endotoxin EXCEPT | back 30 b.Clostridium botulinum. |
front 31 Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed, | back 31 b.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 d.engulf the bacteria. |
front 33 Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? | back 33 a.inducing TNF |
front 34 Injectable drugs are tested for endotoxins by | back 34 d.the Limulus amoebocyte lysate test. |
front 35 Endotoxins in sterile injectable drugs could cause | back 35 c.septic shock symptoms. |
front 36 Gram-negative septic shock results from the following events. What is the second step? | back 36 a.LPS is released from gram-negative bacteria. |
front 37 Antibiotics can lead to septic shock if used to treat | back 37 a.gram-negative bacterial infections. |
front 38 Which of the following is NOT a cytopathic effect of viruses? | back 38 b.toxin production |
front 39 Table 15.1 Bacterium Portal of Entry ID50 Table 15.1 shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery a.decreases the risk of staphylococcal infection. | back 39 a.decreases the risk of staphylococcal infection. |
front 40 Table 15.2 Bacterium ID50 Which organism in Table 15.2 most easily causes an infection? a.E. coli O157:H7 | back 40 d.Legionella pneumophila |
front 41 Table 15.2 Bacterium ID50 Which organism in Table 15.2 causes the most severe disease? a.E. coli O157:H7 | back 41 e.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 b.streptococcal colonization is necessary for periodontal disease. |
front 43 Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by | back 43 e.lysogenic conversion. |
front 44 In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes | back 44 b.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 c.endotoxin. |
front 46 The best description of direct damage by a pathogen is | back 46 d.host cells destroyed when pathogens metabolize and multiply |
front 47 Which is NOT specifically employed by pathogens to avoid destruction by phagocytosis? | back 47 c.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 a.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 c.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 b.Shigella sonnei - coagulase |