Exam 4 - (CH 25) Mycoplasma and Ureaplasma Textbook Review Questions Flashcards
Primary atypical pneumonia differs from typical pneumonia caused by Streptococcus pneumoniae in that it is
A. seasonal, asymptomatic, and more common in neonates.
B. more severe and most common in older adults and immunocompromised patients.
C. milder and has a higher incidence in young adults.
D. asymptomatic and has a higher incidence in patients in long-term acute care facilities.
C. milder and has a higher incidence in young adults.
This organism has been recovered from more than 60% of normal sexually active females.
A. Mycoplasma genitalium
B. Mycoplasma fermentans
C. Ureaplasma urealyticum
D. Listeria monocytogenes
C. Ureaplasma urealyticum
It is recommended that culture for Mycoplasma hominis and Ureaplasma spp. be attempted on the cerebrospinal fluid (CSF) specimen from a newborn when
A. there are signs of meningitis, but the Gram-stain and routine CSF culture are negative.
B. the mother had a routine Ureaplasma screen at 35 weeks’ gestation but was asymptomatic.
C. the newborn has low birth weight, fever of unknown origin, and failure to thrive.
D. None of the above. CSF is not an appropriate specimen type for these organisms.
A. there are signs of meningitis, but the Gram-stain and routine CSF culture are negative.
Ureaplasma urealyticum has been reported to cause chronic inflammatory disease in patients with
A. diabetes.
B. hypogammaglobulinemia.
C. multiple myeloma.
D. Cushing’s syndrome.
B. hypogammaglobulinemia.
Which of the following swabs is acceptable for Mycoplasma testing?
A. Calcium alginate swab with plastic shaft
B. Dacron polyester swab with wood shaft
C. Cotton swab with wood shaft
D. All of the above
A. Calcium alginate swab with plastic shaft
Mycoplasma pneumoniae and Mycoplasma genitalium require ____ as their major energy source.
A. urea
B. arginine
C. blood
D. glucose
D. glucose
Ureaplasma spp. require the growth media to have a pH of
A. 2.0.
B. 4.0.
C. 6.0.
D. 8.0.
C. 6.0
The typical colony appearance of Mycoplasma hominis on A7 agar can be described as
A. molar tooth.
B. fried egg.
C. foamy.
D. large, filamentous, and granular.
B. fried egg
A slow-growing mycoplasma from a respiratory specimen producing a yellow color in SP4 broth is most likely
A. Mycoplasma hominis.
B. Ureaplasma urealyticum.
C. Mycoplasma salivarium.
D. Mycoplasma pneumoniae.
D. Mycoplasma pneumoniae.
Ureaplasma urealyticum isolates that are urease positive are this color due to the deposition of manganese dioxide.
A. Rose to salmon
B. Blue to green
C. Yellow to chartreuse
D. Golden-brown
D. Golden-brown
From what source did the neonate described in the Case in Point likely acquire the infection?
Case in Point
A premature male neonate in the neonatal intensive care unit, who weighed 1.5 lb at birth (low birth weight), developed signs of meningitis, and a lumbar puncture was performed. The results of a white blood cell count of cerebrospinal fluid (CSF) were negative; The Gram stain result was “no organisms seen”; and the result of routine culture at 3 days was reported “no growth.” The infant was still symptomatic at this time, and the pediatric infectious disease physician, after consultation with the microbiology laboratory, performed another lumbar puncture and ordered additional cultures. An organism was recovered by the laboratory.
The infant in the Case in Point most likely acquired the infection when passing through the birth canal; however, studies have also demonstrated neonatal infections following cesarean deliveries.
Would routine prenatal culture of the mother have yielded this organism?
Case in Point
A premature male neonate in the neonatal intensive care unit, who weighed 1.5 lb at birth (low birth weight), developed signs of meningitis, and a lumbar puncture was performed. The results of a white blood cell count of cerebrospinal fluid (CSF) were negative; The Gram stain result was “no organisms seen”; and the result of routine culture at 3 days was reported “no growth.” The infant was still symptomatic at this time, and the pediatric infectious disease physician, after consultation with the microbiology laboratory, performed another lumbar puncture and ordered additional cultures. An organism was recovered by the laboratory.
Because of their fastidious nature, routine prenatal cultures would not have detected most mycoplasma. M. hominis will grow on routine media, but it forms pinpoint colonies after 48 hours of incubation that could be easily missed unless efforts were made to specifically detect this agent.
Why was the Gram stain result negative?
Case in Point
A premature male neonate in the neonatal intensive care unit, who weighed 1.5 lb at birth (low birth weight), developed signs of meningitis, and a lumbar puncture was performed. The results of a white blood cell count of cerebrospinal fluid (CSF) were negative; The Gram stain result was “no organisms seen”; and the result of routine culture at 3 days was reported “no growth.” The infant was still symptomatic at this time, and the pediatric infectious disease physician, after consultation with the microbiology laboratory, performed another lumbar puncture and ordered additional cultures. An organism was recovered by the laboratory.
The mollicutes lack a cell wall; therefore they do not Gram stain.
How does primary atypical pneumonia caused by M. pneumoniae differ from pneumonia caused by S. pneumoniae?
Primary atypical pneumonia is milder than pneumococcal pneumonia and more often seen in young adults compared with older adults. In addition, unlike pneumococcal pneumonia, primary atypical pneumonia does not have a seasonal incidence, although slightly more cases occur in fall and early winter.
List the four common species of mollicutes associated with the genitourinary tracts of humans.
- Mycoplasma hominis
- M. genitalium
- Ureaplasma urealyticum
- U. parvum
What special stain is used on suspected colonies of Mycoplasma?
Dienes or methylene blue stains are used to stain suspected mycoplasma colonies.
What culture media are used to isolate M. pneumoniae, M. hominis, and U. urealyticum?
A7 and A8 are selective and differential media for the isolation of M. hominis and U. urealyticum. In addition, Shepard’s 10B arginine broth can also be used. M. hominis and M. pneumoniae can be grown on SP4 broth, if arginine is added for the latter. M. hominis is the least fastidious of the mollicutes and will grow on sheep blood and chocolate agars.
What is the significance of isolating M. hominis from a vaginal specimen?
The mollicutes do not cause vaginitis. However, there is evidence that M. hominis can contribute to bacterial vaginosis. M. hominis has also been isolated from the endometrium and fallopian tubes of women with salpingitis. Meningitis in neonates due to M. hominis and U. urealyticum has been reported. Infection could have originated during delivery.
What current serologic assays are available to demonstrate M. pneumoniae antibodies?
Complement fixation assays had been the primary serologic method to detect anti– M. pneumoniae antibodies. However, because of technical problems, enzyme immunoassays and immunofluorescent antibody methods are now more commonly used.
Why are the mollicutes universally resistant to penicillin?
The mollicutes lack a cell wall and are therefore inherently resistant to the β-lactams: penicillins and cephalosporins.
Points to Remember
■ The mollicutes are minute organisms characterized by the lack of a cell wall.
■ The most clinically significant species of the Mycoplasmataceae include M. pneumoniae, M. hominis, and Ureaplasma spp., although others are beginning to be recognized as opportunistic pathogens.
■ M. pneumoniae is an important cause of community-acquired, atypical pneumonia.
■ M. hominis and Ureaplasma spp. are genital mycoplasma commonly diagnosed by culture, although PCR technology is also available.
■ Because of the lack of a cell wall, the mycoplasmas are inherently resistant to the β-lactam antibiotics.
