101-200 Flashcards
(101 cards)
Acid-fast staining of a smear prepared from digested sputum showed slender, slightly curved, beaded, red mycobacterial rods. Growth on Middlebrook 7H10 slants produced buff-colored microcolonies with a SERPENTINE PATTERN after
14 days at 37°C. NIACIN AND NITRATE REDUCTION TESTS WERE POSITIVE. What is the most probable presumptive identification?
A. Mycobacterium tuberculosis
B. Mycobacterium ulcerans
C. Mycobacterium kansasii
D. Mycobacterium avium–intracellulare complex
A. Mycobacterium tuberculosis
An isolate of Staphylococcusaureuswas cultured from an ulcer obtained from the leg of a diabetic 79-year-old female patient. The organism showed resistance to methicillin. Additionally, this isolate should be tested for resistance or susceptibility to:
A. Erythromycin
B. Gentamicin
C. Vancomycin
D. Kanamycin
C. Vancomycin
A commercial fisherman with red sores on his hands was seen by his physician. Biopsy and culture of one of the lesions grew an organism with the characteristics listed below:
Nonhemolytic on SBA
Gram-positive bacilli, no spores observed
Catalase negative
Hydrogen sulfide production positive
Growth in gelatin resembled a test-tube brush
What is the most likely identification?
A. Rhodococcus equi
B. Listeria monocytogenes
C. Lactobacillus acidophilus
D. Erysipelothrix rhusiopathiae
D. Erysipelothrix rhusiopathiae
- A discharge from an infected ear grows a colorless colony type on MacConkey agar that swarms on sheep BAP. This oxidase-negative, gram-negative rod is resistant to tetracycline and colistin on a routine Kirby-Bauer antimicrobial susceptibility test and gives the following biochemical reactions:
Phenylalanine deaminase (PAD): positive
Hydrogen sulfide (H2S): positive
Urease: positive
Lysine: negative
Ornithine: positive
Indole: negative Citrate: positive
The organism described is:
A. Citrobacter freundii
B. Morganella morganii
C. Proteus mirabilis
D. Proteus vulgaris
C. Proteus mirabilis
- Most common type of microscopy performed in the urinalysis laboratory:
A. Bright-field microscopy
B. Phase-contrast microscopy
C. Polarizing microscopy
D. Interference-contrast microscope
A. Bright-field microscopy
106.Enhances visualization of elements with low refractive indices, such as hyaline casts, mixed cellular casts, mucous threads, and Trichomonas:
A. Bright-field microscopy
B. Phase-contrast microscopy
C. Polarizing microscopy
D. Interference-contrast microscope
B. Phase-contrast microscopy
- A 1-week-old newborn develops meningitis. Short, gram-positive rods are isolated. History reveals that the mother had eaten unpasteurized cheese from Mexico during pregnancy, and she recalled having a flu-like illness. Which of the following is the most likely etiologic microorganism?
A. Corynebacterium diphtheriae
B. Escherichia coli
C. Group B streptococci
D. Listeria monocytogenes
E. Streptococcus pneumoniae
D. Listeria monocytogenes
- Metabolism of glucose molecule to pyruvate or lactate for production of energy
A. Gluconeogenesis
B. Glycogenolysis
C. Glycogenesis
D. Glycolysis
D. Glycolysis
Formation of glucose-6-phosphate from noncarbohydrate sources
A. Gluconeogenesis
B. Glycogenolysis
C. Glycogenesis
D. Glycolysis
A. Gluconeogenesis
Breakdown of glycogen to glucose for use as energy
A. Gluconeogenesis
B. Glycogenolysis
C. Glycogenesis
D. Glycolysis
B. Glycogenolysis
- Conversion of glucose to glycogen for storage
A. Gluconeogenesis
B. Glycogenolysis
C. Glycogenesis
D. Glycolysis
C. Glycogenesis
- Which set of results is consistent with uncompensated respiratory alkalosis?
A. pH 7.70 HCO3- 30 mmol/L pCO2 25 mm Hg
B. pH 7.66 HCO3- 22 mmol/L pCO2 20 mm Hg
C. pH 7.46 HCO3- 38 mmol/L pCO2 55 mm Hg D. pH 7.36 HCO3- 22 mmol/L pCO2 38 mm Hg
B. pH 7.66 HCO3- 22 mmol/L pCO2 20 mm Hg
TIPS FOR EVALUATING ACID-BASE DISORDERS
- Look at the pH: determine if acidosis or alkalosis
- Compare pCO2 and HCO3 pCO2 going opposite to pH – RESPIRATORY
Abnormal pCO2 respiratory
[↓pH ↑pCO2 respiratory acidosis]
[↑pH ↓pCO2 respiratory alkalosis]
HCO3- going same direction as pH - METABOLIC
Abnormal HCO3- metabolic
[↓pH ↓HCO3- metabolic acidosis]
[↑ pH ↑ HCO3- metabolic alkalosis] - If pH is normal, full compensation occurred
- If main compensatory mechanism kicked in, but pH still out of normal range, partial compensation has occurred
- When semi-automated urine chemistry analyzers are used, the color that develops on the reaction pads is measured by:
A. Spectrophotometry.
B. Reflectance photometry.
C. Fluorescence photometry.
D. Comparing reaction pads with a color chart.
B. Reflectance photometry.
A 17-year-old female with cystic fibrosis is diagnosed with pneumonia. A sputum sample grew gram-negative bacilli with yellow (check) , smooth colonies that have the following biochemical reactions:
Oxidase: positive (check)
TSI: alk/alk
Glucose: oxidized
Fluorescence: negative
Lysine decarboxylase: positive
The most likely organism is:
A. Burkholderia cepacia
B. Klebsiella pneumoniae
C. Shewanella putrefaciens
D. Stenotrophomonas maltophilia
A. Burkholderia cepacia
- The most important practice in preventing the spread of disease is:
A. Wearing masks during patient contact
B. Proper hand washing
C. Wearing disposable laboratory coats
D. Identifying specimens from known or suspected HIV-and HBV-infected patients with a red label
B. Proper hand washing
- Identify the enzyme deficiency responsible for type 1 glycogen storage disease (von Gierke’s disease).
A. Glucose-6-phosphatase
B. Glycogen phosphorylase
C. Glycogen synthetase
D. β-Glucosidase
A. Glucose-6-phosphatase
- Which of the following abnormal laboratory results is found in von Gierke’s disease?
A. Hyperglycemia
B. Increased glucose response to epinephrine administration
C. Metabolic alkalosis
D. Hyperlipidemia
D. Hyperlipidemia
ANSWER & IDENTIFY THE ORGANISM
A wound (skin lesion) specimen obtained from a newborn grew predominantly β-hemolytic colonies of gram-positive cocci on 5% sheep blood agar. The newborn infant was covered with small skin eruptions that gave the appearance of a “scalding of the skin.” The gram-positive cocci proved to be catalase positive. Which tests should follow for the appropriate identification?
A. Optochin, bile solubility, PYR
B. Coagulase, glucose fermentation, DNase (S. aureus)
C. Bacitracin, PYR, 6.5% salt broth
D. CAMP, bile-esculin, 6.5% salt broth
B. Coagulase, glucose fermentation, DNase (S. aureus)
The following results were obtained from a pure culture of gram-negative rods recovered from the pulmonary secretions of a 10-year-old cystic fibrosis patient with pneumonia:
Oxidase = +
Motility = +
Glucose OF (open) = +
Gelatin hydrolysis = +
Growth at 42°C = +
Flagella = + (polar, monotrichous)
Which is the most likely organism?
A. Burkholderia pseudomallei
B. Pseudomonas stutzeri
C. Burkholderia cepacia
D. Pseudomonas aeruginosa
D. Pseudomonas aeruginosa
Which of the following aids in di erentiating a spherical transitional cell from a round renal tubular cell?
A. Spherical transitional cell is larger
B. Eccentrically-placed nucleus in the renal tubular cell
C. Eccentrically-placed nucleus in the spherical transitional cell
D. Round renal tubular cell is larger
B. Eccentrically-placed nucleus in the renal tubular cell
A scraping from a painful, inflamed wound is found to contain numerous gram-negative bacteria. Upon questioning, the feverish patient states that he was bitten by a cat while trying to rescue it from a storm drain earlier in the day. Given these observations, which of the following organisms is the most likely cause of infection?
A. Aeromonas species
B. Campylobacter jejuni
C. Pasteurella multocida
D. Pseudomonas aeruginosa
E. Yersinia enterocolitica
C. Pasteurella multocida
A teenaged boy su ered a foot laceration while swimming in a polluted water area in a river. He did not seek medical treatment, and the wound developed a foul-smelling exudate. One of the bacteria isolated from the abscess exudate was missing superoxide dismutase, catalase, and a peroxidase. Which of the following statements best describes this microorganism?
A. It is a capnophile
B. It is a facultative anaerobe
C. It is a microaerophile
D. It is an anaerobe
E. It is an obligate aerobe
D. It is an anaerobe
Seventy (70) percent recirculated to the cabinet work area through HEPA; 30% balance can be exhausted through HEPA back into the room or to outside through a canopy unit:
A. BSC Class I
B. BSC Class II, A1
C. BSC Class II, B1
D. BSC Class II, B2
B. BSC Class II, A1