MLT 232 Microbiology, Unit 2 (101-150)

114) Negative mycobacterial cultures are reported final and the cultures are discarded after what period?

8 weeks

120) In the identification of mycobacterial isolates, the niacin test involves the:

accumulation of niacin in the medium in which the organism is growing

115) The first test that is always performed on organisms growing on solid or liquid mycobacterial media is a(n):

acid-fast stain

139) A self-limiting illness and the most common clinical syndrome associated with leptospirae that includes fever, headache, myalgia, and aseptic meningitis in the immune stage is called

anicteric leptospirosis

123) The 3-day test that is useful for identifying the rapid growers, M. fortuitum and M. chelonae, and that measures the rate by which this enzyme breaks down phenolphthalein disulfate into phenolphthalein and other salts is the ____________ test.

arylsulfatase

116) Quality control is performed to test the validity of catalase production at 68° C. M. fortuitum and M. tuberculosis are used, which yield a positive and negative reaction, respectively. Which one of the following statements explains this discrepancy?

No discrepancy is present. M. fortuitum is catalase-positive and M. tuberculosis is catalase-negative at 68° C.

111) Fluorescent staining is more sensitive than conventional carbolfuchsin stains. What counterstain is used during the procedure?

Potassium permanganate

138) A test that uses gelatin particles sensitized with T. pallidum subsp. pallidum antigens to detect specific antitreponemal antibodies in patient serum is called the __________ test.

TP-PA

117) When culturing for Mycobacterium, rapid growers usually produce colonies within how many days after subculture?

3 to 4 days

119) For reliable results, the niacin test should be performed only from cultures that are at least:

3 weeks old and show at least 50 colonies on Löwenstein-Jensen medium

110) Acid-fast smears should be examined carefully by scanning at least ________ oil immersion field.

300

112) Optimal conditions for most mycobacterial cultures are:

35° C in the dark in an atmosphere of 5% to 10% CO2 and high humidity.

141) The Centers for Disease Control and Prevention (CDC) recommendations for testing in suspected cases of Lyme disease are to screen with ______ and confirm with ________.

IFA; immunoblotting

109) The stain that does not require heating the slide for better penetration of stain into the mycobacterial cell wall is known as the:

Kinyoun

127) Long, slender, helically curved, gram-negative bacilli with hooked ends are identified as belonging to which species

Leptospira

105) The nonpathogenic Mycobacterium commonly found in tap water, which has been a problem when tap water or deionized water has been used in the preparation of smears, is:

M. gordonae

124) Which continuous growth system uses a CO2 sensor to monitor mycobacterial growth?

BacT/Alert

150) Which of the following intestinal parasites is found in humans and also in pigs?

Balantidium coli

146) Babesia spp. is transmitted via the bite of a tick and can cause severe disease in patients who have been splenectomised or who are immunocompromised. To diagnose accurately these patient populations, the specimen of choice is:

Blood

144) The Jarisch-Herxheimer reaction is associated with the clearance of organism from the bloodstream and the release of cytokines within hours of antibiotic treatment. With which spirochete is this condition associated?

Borrelia

130) The most common vector-borne disease in North America and Europe transmitted by the bite of Ixodes ticks is caused by:

Borrelia burgdorferi

145) This protozoa has a trophozoite stage but no cyst stage and reproduces via longitudinal binary fission. The parasite belongs to which category?

Flagellates

149) The eggs of which of the following intestinal parasites are not commonly found in feces and must be detected by other diagnostic techniques?

Enterobius vermicularis

137) A specific treponemal serologic test performed by overlaying whole treponemes that are fixed to a slide with serum from patients suspected of having syphilis and using fluorescein-conjugated antihuman antibody reagent to detect specific antitreponemal antibodies is called the _________ test

FTA-ABS

101) Specimens for Mycobacterium studies that require concentration, decontamination, or liquefaction include:

sputum.

125) A fisherman who cut himself on a fishing hook later develops a cutaneous disease at the inoculation site. The exudate is aspirated and set up on a routine AFB medium for culture. It is incubated at 37° C, but no growth is observed after 8 weeks; however, a slide of the exudate was AFB-positive. Which one of the following statements explains these findings?

The organism should have been incubated at 30° C

126) Long, slender, helically curved, gram-negative bacilli with tight coils are identified as belonging to which species

Treponema

143) An automated system uses bead-capture technology in the detection of which of the following spirochetes?

Treponema

148) A bone marrow aspirate is examined for the presence of parasites from a patient who has been traveling in Latin America for several months and who came in contact with a triatomid bug. Which parasite will most likely be identified?

Trypanosoma cruzi

136) A nontreponemal flocculation serologic test in which soluble antigen particles are coalesced to form larger particles that are visible as clumps when they are aggregated by antibody is called the __________ test

VDRL

131) A destructive lesion of the gums, also known as acute necrotizing ulcerative gingivitis, that is caused by oral spirochetes and other bacteria is known as

Vincent's disease

118) Under what circumstance might slow-growing mycobacteria appear to produce colonies in a few days?

When the inoculum is too heavy

108) The stain that requires heating the slide for better penetration of stain into the mycobacterial cell wall is known as the:

Ziehl-Neelsen

122) In the identification of mycobacterial isolates, the Tween 80 test involves:

a lipase that is able to hydrolyze polyoxyethylene sorbitan monooleate into oleic acid and polyoxyethylated sorbitol.

133) A stage of venereal syphilis, characterized by tissue destruction, central nervous system disease, cardiovascular abnormalities, eye disease, and granuloma-like lesions, is known as ________ syphilis

tertiary

102) Sodium hydroxide (NaOH), Zephiran-trisodium phosphate, N-acetyl-L-cysteine-NaOH (NALC-NaOH), and oxalic acid are associated with:

digestion and decontamination of specimens for mycobacterial studies

106) The fluorochrome method of staining Mycobacterium:

enables the smear to be initially examined at lower magnifications.

147) Wuchereria, Brugia, Loa, and Onchocerca are all classified as:

filarial nematodes.

103) The type of specimen collected for mycobacterial studies that must be neutralized with 10% sodium carbonate is:

gastric lavage

140) The most severe illness associated with leptospirae, with symptoms of liver, kidney, and/or vascular dysfunction with lethal pulmonary hemorrhage and sometimes death, is called

icteric leptospirosis

107) One drawback associated with the fluorochrome stain method for detecting Mycobacterium is that:

many rapid growers may not appear fluorescent with these reagents

121) In the identification of mycobacterial isolates, the catalase test involves the:

measurement of the height of a column of bubbles of oxygen.

142) A patient has a reactive RPR result and a positive FTA-ABS test. The drug of choice to treat this infection is:

penicillin G

113) Optimal conditions for the recovery of M. haemophilum from specimens include:

placement of an X-factor disk on the media.

104) On Gram stain, mycobacteria appear as:

poorly stained, beaded, gram-positive bacilli

132) A stage of venereal syphilis characterized by the appearance of a chancre is known as __________ syphilis

primary

134) Treponemal antibodies are those that are

produced against antigens of the organisms themselves

135) Nontreponemal antibodies are those that are:

produced by infected patients against components of mammalian cells

129) A widely used nontreponemal serologic assay is the ________ test.

rapid plasma reagin (RPR)

128) Systemic symptoms, such as fever, weight loss, malaise, and a loss of appetite, along with a widespread rash, can be observed in patients suffering from _________ syphilis.

secondary