Chapter 23: The Spirochetes. All Answers

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MULTIPLE CHOICE 1. Spirochetes are made up of all the following except: a. Helicobacter. b. Leptospira. c. Borrelia. d. Treponema. A Helicobacter belongs to the Vibrionaceae family. The ... order Spirochaetales contains two families, Leptospiraceae and Spirochaetaceae. The Leptospiraceae family contains the genus Leptospira, and the Spirochaetaceae family contains the genera Borrelia and Treponema. REF: 530 OBJ: Level 1: Recall 2. What structure is responsible for motility in spirochetes? a. Axiles b. Periplasmic flagella c. Flexible cell wall d. Compressed nucleus B The spirochetes differ from other bacteria in that they have a flexible cell wall around which several fibrils are wound. These fibrils, termed the periplasmic flagella (also known as the axial fibrils, axial filaments, endoflagella, and periplasmic fibrils), are responsible for motility. REF: 530 OBJ: Level 1: Recall 3. Factors that may play a role in pathogenicity of Leptospira include all the following except: a. hemolysin. b. endotoxins. c. pancytopenia in host. d. decreased phagocytosis in host. C Factors that may play a role in pathogenicity include reduced phagocytosis in the host, a soluble hemolysin produced by some virulent strains, cell-mediated sensitivity to leptospiral antigen by the host, and small amounts of endotoxins produced by some strains. REF: 530 OBJ: Level 1: Recall 4. What is a Leptospira infection called when it becomes a severe systemic disease? a. Niemann-Pick b. Bordet-Gengou c. Gaucher’s disease d. Weil’s disease D Severe systemic disease (Weil’s disease) includes renal failure, hepatic failure, and intravascular disease and may result in death. REF: 530 OBJ: Level 1: Recall 5. All of the following symptoms are characteristic of Weil’s disease except: a. pneumonia. b. renal failure. c. hepatic failure. d. intravascular disease. A Severe systemic disease (Weil’s disease) includes renal failure, hepatic failure, and intravascular disease and may result in death. REF: 530 OBJ: Level 1: Recall 6. An animal attendant at the zoo became ill. Symptoms included fever, chills, headache, severe myalgia, and malaise. This person’s urinalysis was abnormal with protein and blood present. A couple of weeks earlier, the attendant was handling the chimpanzees and one of the chimps urinated on him. What is the most likely cause of illness? a. Borrelia b. Leptospira c. Treponema d. Helicobacter B Leptospirosis is a zoonotic disease in humans primarily associated with occupational exposure. In the natural host, leptospira live in the renal tubules and are excreted in the urine. REF: 531 OBJ: Level 3: Synthesis 7. Acceptable specimens during the first week of leptospirosis include which the following? a. Cerebrospinal fluid (CSF) b. Blood c. Urine d. Both a and b D During the acute phase (first week) of the disease, blood or CSF should be collected. Because leptospira can be shed intermittently for weeks, urine can be cultured after the first week of the illness. REF: 531 OBJ: Level 1: Recall 8. What medium is used in the laboratory to grow leptospiral organisms? a. MacConkey b. Fletcher’s c. Sheep blood agar d. None of the above B Isolation of leptospira is accomplished by direct inoculation of 1 to 2 drops of freshly drawn blood or cerebrospinal fluid (CSF) into laboratory media, such as Fletcher’s, Stuart, or EMJH, and incubating the media in the dark at room temperature. REF: 530 OBJ: Level 1: Recall 9. Leptospiral organisms are susceptible to all the following antibiotics except: a. streptomycin. b. tetracycline. c. penicillin. d. macrolides. C Susceptibility testing of leptospira is not often performed in the clinical laboratory; however, leptospira have been shown to be susceptible to streptomycin, tetracycline, doxycycline, and the macrolide antibiotics in vitro. REF: 531 OBJ: Level 1: Recall 10. What diseases do Borrelia spp. cause? a. Undulant and hemorrhagic fevers b. Lyme disease and parrot fever c. Rocky Mountain spotted fever and relapsing fever d. Lyme disease and relapsing fever D The genus Borrelia comprises several species of spirochetes that are morphologically similar but have different pathogenic properties and host ranges. Most species cause relapsing fever; however, B. burgdorferi is the etiologic agent of Lyme disease. REF: 530 OBJ: Level 1: Recall 11. What organism causes relapsing fever? a. Borrelia recurrentis b. B. burgdorferi c. Leptospira interrogans d. C. psittaci A B. recurrentis causes relapsing fever. As the name suggests, the acute infection causes febrile episodes that subside spontaneously and tend to recur over a period of weeks. REF: 532 OBJ: Level 1: Recall 12. How are Borrelia organisms transmitted to the host? a. Respiratory droplets b. Arthropods c. Birds d. Blood or body fluids B Borrelia organisms are transmitted to a host by an arthropod vector—a tick or a louse. REF: 532 OBJ: Level 1: Recall 13. What is the drug of choice for treating Borrelia infections? a. Aminoglycosides b. Macrolides c. Tetracyclines d. Penicillins C Borrelia spp. are susceptible to many antimicrobial agents; however, tetracyclines are the drugs of choice because they reduce the relapse rate and rid the central nervous system of the spirochete. REF: 532 OBJ: Level 1: Recall 14. A young woman notices a bruise that looks like an erythema chronicum migrans lesion on her lower leg. She cannot remember getting bruised, even though she went hiking through the woods last weekend. The bruise goes away in about a week and she thinks nothing more about it. About 2 weeks later, she begins to feel very bad. She has joint and bone pain, extreme fatigue, and her heart just “doesn’t feel right.” What disease does she have, and what antibiotic is used to treat it? a. Lyme disease and doxycycline b. Relapsing fever and macrolides c. Parrot fever and penicillin d. Hemorrhagic fever and gentamicin A Infection with Borrelia burgdorferi includes two stages, the first of which is localized. Stage 1: about 60% of patients exhibit erythema chronicum migrans, the classic skin lesion that is normally found at the site of the tick bite. It begins as a red macule and expands to form a large annular erythema with partial central clearing. Stage 2: This is an early disseminated disease and produces widely variable symptoms including secondary skin lesions, migratory joint and bone pain, alarming neurologic and cardiac pathology, splenomegaly, severe malaise, and fatigue. This is treated with doxycycline. REF: 533 OBJ: Level 3: Synthesis 15. All of the following diseases are produced by Treponema except: a. syphilis. b. elephantiasis. c. yaws. d. pinta. B The genus Treponema comprises four microorganisms that are pathogenic for hum T. pallidum subsp. pallidum, the causative agent of syphilis; T. pallidum subsp. pertenue, the causative agent of yaws; T. pallidum subsp. endemicum, the causative agent of endemic syphilis; and T. carateum, the causative agent of pinta. REF: 533 OBJ: Level 1: Recall 16. A man is taking a shower and notices this lesion on his penis that is not tender but is firm with a clean surface and raised edges. He is quite dismayed, so he goes to his physician. The physician does a rapid plasmin reagin (RPR) and a darkfield microscopy. Both tests are positive. What is the physician’s probable diagnosis? a. Gonorrhea b. Nongonococcal urethritis (NGU) c. Syphilis d. Human papillomavirus (HPV) C The primary syphilis lesion develops 10 to 90 days after infection and is a result of an inflammatory response to the infection at the site of the inoculation. The lesion, known as the chancre, is typically a single erythematous lesion that is not tender but is firm with a clean surface and raised border. The lesion is teeming with treponemes and is extremely infectious. REF: 534 OBJ: Level 3: Synthesis 17. Where on the body is the secondary syphilis rash typically seen? a. Chest and back b. Back and soles c. Buttocks and palms d. Palms and soles D Approximately 2 to 12 weeks after development of the primary lesion, the patient may experience secondary disease, with clinical symptoms of fever, sore throat, generalized lymphadenopathy, headache, and rash. The rash is unusual in that it can also occur on the palms and soles. REF: 534 OBJ: Level 1: Recall 18. An untreated patient develops tertiary syphilis _____ after the initial infection. a. decades b. 2 to 3 years c. 1 year d. 5 years A The remaining one third of patients develop tertiary or late syphilis generally decades after initial infection. REF: 534 OBJ: Level 1: Recall 19. All of the following are symptoms of tertiary syphilis except: a. gummas in the skin, bones, and liver. b. encephalitis. c. aortitis. d. aortic valve insufficiency. B Symptoms of tertiary syphilis include the development of granulomatous lesions in skin, bones, and liver; degenerative changes in the central nervous system; and syphilitic cardiovascular lesions, particularly aortitis and aortic valve insufficiency. REF: 534 OBJ: Level 1: Recall 20. How is congenital syphilis transmitted from the mother to her unborn child? a. During birth from the birth canal b. During the microhemorrhages that occur as the placenta breaks away from the uterus c. Crossing the placenta d. None of the above C Treponemes can be transmitted from an infected mother to her fetus by crossing the placenta. REF: 534 OBJ: Level 2: Interpretation 21. Early-onset congenital syphilis is characterized by all the following symptoms except: a. osteochondritis. b. anemia. c. hepatosplenomegaly. d. encephalitis. D Early-onset congenital syphilis, onset at less than 2 years of age, is characterized by mucocutaneous lesions, osteochondritis, anemia, hepatosplenomegaly, and central nervous system involvement. It occurs when mothers have early syphilis during pregnancy. REF: 534 OBJ: Level 1: Recall 22. What is the primary method used to screen for syphilis infections? a. Serologic b. Microscopy c. Culture d. Enzyme immunoassay (EIA) A Serology is the primary method used for the laboratory diagnosis of syphilis. REF: 535 OBJ: Level 1: Recall 23. What is an example of a nontreponemal test? a. Rapid plasmin reagin (RPR) b. Fluorescent treponemal antibody, absorbed (FTA-ABS) c. Treponema pallidum particle agglutination (TPPA) d. Microhemagglutination-Treponema pallidum (MHA-TP) A The two nontreponemal tests widely used today are the Venereal Disease Research Laboratory (VDRL) and the RPR. REF: 535 OBJ: Level 1: Recall 24. What is a confirmatory test for a positive rapid plasmin reagin (RPR)? a. Venereal Disease Research Laboratory (VDRL) b. Fluorescent treponemal antibody, absorbed (FTA-ABS) c. Enzyme immunoassay (EIA) d. Darkfield B The treponemal tests detect antibodies specific for treponemal antigens. They are helpful in the detection of late-stage infections and the confirmation of positive nontreponemal test results. Two commonly used treponemal tests are the FTA-ABS and the Treponema pallidum particle agglutination (TPPA) test. REF: 535 OBJ: Level 1: Recall 25. What is the drug of choice used to treat syphilis? a. Tetracycline b. Fluoroquinolones c. Penicillin d. Macrolides C Penicillin is the drug of choice for treating patients with syphilis. REF: 535 OBJ: Level 1: Recall 26. Once infected with Borrelia recurrentis, a 2- to 15-day incubation period follows where high numbers of organisms are found in the blood. The infected individual experiences high fever, rigors, severe headache, muscle pains, and weakness. This febrile period lasts for about 3 to 7 days, but ends quickly with the induction of an immune response. However, a similar but less severe course of symptoms recurs several days to weeks later. What causes this relapse? a. The organism systematically changes its surface antigens during the course of a single infection. b. The organism produces extracellular toxins that cause the symptoms. c. This organism survives inside infected cells and once the cell dies, the organism is released into the blood, causing this relapse. d. This relapse occurs as the host is trying to mount the secondary antibody response. A Borrelia recurrentis has the ability to change its surface antigens during the course of an infection. This means that the specific immune response mounted by the host is no longer effective against the new bacterial antigen. This is why the relapse occurs. B. recurrentis does not produce extracellular toxins. This organism does not survive once phagocytized. The secondary antibody response occurs in conjunction with the primary response, and there is no lapse to allow for a recurrence of symptoms. REF: 532 OBJ: Level 3: Synthesis [Show More]

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