ASCP two
Which of the following cast(s) might be found in the urine of a healthy individual after strenuous exercise: More than one answer is correct. Please select all correct answers A. Epithelial cell casts B. Hyaline casts C. Granular casts D. Waxy casts
B & C
The colonies seen in the upper frame, grown after 48 hours incubation aerobically at 35°C, and the accompanying gram stain in the lower frame are uncommonly associated with human disease, but have been associated with septicemia, bronchopneumonia, osteomyelitis and other infections, particularly in intravenous drug users. The most likely identification is: Please select the single best answer Clostridium septicum Bacillus circulans Listeria monocytogenes Lactobacillus species
Bacillus circulans
Which of the following Rh antigens is found the highest frequency in the Caucasian population: Please select the single best answer A. C B. E C. c D. e
D Antigen frequency in whites: D = 84%, C = 70%, E = 30%. c = 80%, e = 98%.
Which one of the following is NOT usually associated with Group A Beta Strep? Please select the single best answer Scalded Skin Syndrome Glomerular nephritis Heart muscle damage Rheumatic fever Scarlet fever
Scalded Skin Syndrome; Group A Beta Strep is most commonly associated with glomerular nephritis, heart muscle damage, Rheumatic fever, Scarlet fever. Other types of infections are also possible, such as bacteremia, cellulitis, toxic shock syndrome,etc. but are much less common than those listed above. Scaled Skin Syndrome is usually caused by Staphylococcal infections as opposed to Group A Beta Strep.
Which of the following is not a feature of systemic lupus erythematosus (SLE): Please select the single best answer Increased serum complement Positive ANA Circulating immune complexes Decreased serum complement
A Complement is actually consumed during the immune reactions involved in SLE. Therefore, a decrease in complement is expected. Circulating immune complexes and a positive anti nuclear antibody (ANA) test are both usually present in patients with SLE.
candida vs cryptococcus, disease-wise
Cryptococcosis --> Meningoencephalitis Candidiasis --> Esophagogastritis Cryptococcosis --> Cranial nerve palsy Candidiasis --> Onychomycosis Candidiasis --> Renal abscess Candidiasis --> Thrush
Which of the following represents the approximate percentage of the population that is Rh positive: Please select the single best answer 35 % 65 % 85 % 95 %
85%; Approximately 85% of the population is Rh-positive.
Elizabethkingia is the new genus name for the bacterium formerly called Chryseobacterium meningosepticum, an important agent of neonatal mentingitis (now E. meningoseptica). What biochemical characteristic is unique for the family Flavobacteriaceae among the nonfermenters? The correct answer is highlighted below A. Indole production B. Esculin hydrolysis C. Glucose oxidation D. Resistance to penicillin
A. Among the nonfermenters, the production of indole points to one of the Flavobacteriaceae, including E. meningoseptica. Indole production is weak; therefore, extraction with xylene and reaction with Ehrlich's rather than Kovac's reagent is required for its detection in the standard laboratory procedure. Esculin hydrolysis, oxidation of glucose and susceptibility profiles to penicillin are variable among the Flavobacteriaceae and do not represent characteristics unique to this group.
Sites of active hematopoiesis in the adult are: More than one answer is correct. Please select all correct answers skull sternum scapula pelvis
ALL of the above; Each of the sites listed above are areas where hematopoiesis occurs in adults.
A Proficiency Testing Service (e.g., CAP) reported the following results for a Cholesterol test (unknown Control) reported by your laboratory. Your results were compared with 648 other labs using the same type instrumentation and methodology: Your Result = 168 mg/dl Group Mean = 155 mg/dl Group SD = 11 mg/dl (SD = One Standard Deviation) Group ± 2 SD Range = 22 mg/dl Calculate the value for your Standard Deviation Index and choose the correct answer below: The correct answer is highlighted below A. - 1.18 B. + 0.59 C. + 0.85 D. + 1.18 E. ± 0.18
D. The standard deviation index is the number of group standard deviations that your mean differs from the group mean. The calculation is as follows: SDI = (Your Result - Group Mean) / Group Standard Deviation SDI = (168 mg/dL - 155 mg/dL) / 11 = 1.18
Bioavailability of an oral drug refers to the: Please select the single best answer A. Availability for therapeutic administration B. Ratio of protein-bound to free drug C. Amount of drug transformation D. Fraction of the drug that is absorbed into systemic circulation
D; The bioavailability of an oral drug is the fraction of the drug that is absorbed into systemic circulation. The bioavailability of a drug is calculated by comparing the area under the plasma concentration-time curve of an equivalent dose of the intravenous form and the oral form of the drug. For oral drugs to be effective, bioavailability typically should be greater than 70%.
All of the following may cause systemic mycoses EXCEPT: Please select the single best answer A. Actinomyces israeli B. Nocardia brasiliensis C. Coccidioides immitis D. Nocardia asteroides E. Piedraia hortae
E.
Factor VII- Stable factor Factor VIII- Anti-hemophiliac factor Factor IX- Christmas factor Factor X- Stuart factor
Factor Names
Zollinger-Ellison syndrome is characterized by a large (usually 20-fold) elevation of: Please select the single best answer Cholecystokinin Pepsin Glucagon Gastrin
Gastrin Zollinger-Ellison syndrome, or ZES, is a rare disorder where one or more tumors in the pancreas, duodenum, or intestinal lymph nodes produce gastrin, causing the parietal cells of the stomach to make too much acid (up to 20-fold), leading to multiple peptic ulcers. Cholecystokinin plays a key role in facilitating digestion within the small intestine and is not found in elevated levels in ZES. Pepsin is an enzyme that is released by the chief cells in the stomach to degrade food proteins into peptides and is not found in elevated levels in ZES. Finally, glucagon is a hormone produced by the pancreatic islet cells which raises glucose levels and counteracts the effect of insulin. It is also not associated with ZES.
Which of the following hormones does NOT stimulate gluconeogenesis, the formation of glucose from noncarbohydrate sources such as amino acids, glycerol, and fatty acids? Please select the single best answer Insulin Thyroxine (T4) Cortisol Glucagon
Insulin; Gluconeogenesis is the formation of glucose from noncarbohydrates, such as lactate or amino acids, when carbohydrate intake is absent. The hormone cortisol along with glucagon and thyroxine (T4) all stimulate this metabolic pathway. Insulin does not stimulate this pathway and is therefore the correct answer. Insulin promotes glucose entrance into the cells, therefore regulating blood glucose concentration.
Based on the results of two in-vitro susceptibility testing, patients with septicemia from each of the bacterial species listed below can potentially be treated with vancomycin except: Please select the single best answer Leuconostoc mesenteroides Listeria monocytogenes Bacillus cereus Corynebacterium jeikeium
Leuconostoc mesenteroides; Although most species of gram positive bacteria are susceptible to vancomycin, Leuconostoc species possess innate resistance to this antibiotic (Swenson JM, et al: Antimicrob Agents Chemother 34:543-549, 1990). Therefore, when these species are recovered from patients with associated infections, antibiotic agents other than vancomycin must be used for therapy. Intuitively, as Corynebacterium jeikeium is resistant to many commonly used antibiotic agents, one would presume that it is also resistant to vancomycin; however, most strains remain susceptible. Bacillus cereus and Listeria monocytogenes are susceptible to vancomycin (Applebaum, et al: Diagn Microbiol Infect Dis 14:311-317, 1991).
Nocardia brasiliensis
The colonies are relatively rapidly growing after only 5 days of incubation, but distinct from the rapidly growing colonies of N. asteroids by the deeper yellow-orange pigmentation. The Gram stain morphology is similar to that of Nocardia asteroides, although the individual bacilli of N. brasiliensis are slightly wider and often arrange in chains. The presumptive identification of N. brasiliensis is supported by the hydrolysis of casein and tyrosine on casein agar. Xanthine is not hydrolyzed. Recovery from subcutaneous lesions of the foot of South American field laborers is the most common clinical correlation.
A technologist pipetted 200 microliters of serum in a test tube and added 5 milliliters of saline to the tube. What is the dilution ratio of serum to the total volume in the tube? The correct answer is highlighted below A. 1:2.5 B. 1:25 C. 1:26 D. 1:50 E. 1:52
There is 200 microliters of serum added to 5000 microliters of saline, for a total volume of 5200 microliters. 200 microliters of the total 5200 microliters is a dilution equaling 1:26.
What is the largest constituent of plasma nonprotein nitrogen: Please select the single best answer Ammonia Creatinine Ketones Urea
Urea During the metabolism of protein in the body, the liver converts ammonia into urea. Urea comprises the largest percentage of nonprotein nitrogen (NPN) in plasma at 45-50% plasma concentration of total NPN. More thean 90% of urea is excreted by the kidneys with the rest being excreted via the gastrointestinal tract and skin.
Which of the following is NOT an expected or common laboratory finding in patients with hereditary hemochromatosis (HH)? Please select the single best answer Elevated hemoglobin and hematocrit Elevated transferrin saturation Presence of HFE mutation Elevated serum ferritin
A
Which one of the following usually shows a decrease during an acute phase response? Please select the single best answer Albumin Alpha-1 Antitrypsin Fibrinogen Ceruloplasmin
A
Baseline testing for latent Mycobacterium tuburculosis infection (LTBI) is recommended for all newly-hired health care workers. In which of these cases would a tuberculin skin test (TST) be repeated a second time, one to three weeks after the first test? Please select the single best answer A.The first test is negative and the new employee has never been tested for LTBI before. B. The first test is negative and the new employee has documentation showing he/she had a negative TST 6 months ago. C. The first test is positive. D. None of the above
A A negative TST is repeated 1 - 3 weeks after the first test if the individual being tested does not have a documented record of a negative test that occurred less than or equal to 12 months prior to new employment. A positive TST result should be followed up with additional testing to exclude TB disease. If this is excluded, then the worker should be evaluated for treatment of LTBI.
Which of the following smear techniques can be utilized when processing bone marrow aspirate samples? (Choose all that apply) A. Differential smear B. Touch prep C. Coverslip smear D. Pull prep E. T-prep
A, C, D, E Coverslips, differential smears, pull preps and t-preps are all techniques used when making bone marrow aspirate smears. Touch preps are made from bone marrow biopsy samples.
Which hemoglobin can be decreased in alpha thalassemia? A. Hb A B. Hb A2 C. Hb F D. Hb H
A,B, C; Because alpha chains are needed to form all normal hemoglobins, and alpha thalassemia is the decrease in production of alpha chains, all normal hemoglobins can be decreased in alpha thalassemia: A, A2, and F.
Which of the following blood group system antibodies is the direct antiglobulin test (DAT) most UNRELIABLE in helping to diagnose hemolytic disease of the fetus and newborn (HDFN)? Please select the single best answer ABO Duffy Kell Kidd Rh
ABO; In ABO HDFN, the DAT may be weakly positive or negative, making it an unreliable test. The DAT is usually reliable for antibodies in the other listed blood group systems that cause HDFN.
Which of the following conditions would NOT be associated with an increased level of alpha-fetoprotein? Please select the single best answer Prostate Cancer Hepatocellular Carcinoma Viral Hepatitis Testicular Tumors
AFP is not found in increased levels in patients with prostate cancer. PSA, or prostate specific antigen, is commonly used to screen for prostate cancer. Hepatocellular carcinoma, viral hepatitis, testicular tumors, and pancreatic cancer are all associated with increased levels of AFP. In addition, liver cirrhosis and gastric cancers can also have an associated increased AFP level.
Which of the following serological test results may occur in a patient experiencing a hemolytic transfusion reaction due to antibodies such as anti-c and anti-K? (Select all that apply.) More than one answer is correct. Please select all correct answers A. Patient's antibody strength may initially decrease. B. Patient may develop a positive DAT with mixed-field agglutination. C. Patient's antibody becomes undetectable. D. Patient's antibody increases in titer weeks later.
All are possible. The patient's antibody strength can initially decrease due to adsorbing to transfused antigen-positive donor red cells. This results in a positive DAT with mixed-field agglutination, since only the transfused donor cells are antibody-sensitized. The patient's antibody may even become undetectable at the stage when most of it has adsorbed to the donor cells. Eventually, the patient's antibody increases in strength. This may become apparent weeks later, depending on the relative amount of antibody compared to donor red cells present in the patient's circulation.
The nitrite portion of the test strip can be used to: (Choose ALL correct answers) A. Monitor antibiotic therapy B. Detect a bladder infection in an early stage in pregnant women C. Screen individuals with recurrent infections D. Detect presence of cystitis
All of the above; The nitrite portion of the test strip can be used to monitor antibiotic therapy, detect a bladder infection in an early stage in pregnant women, screen individuals with recurrent infections, and detect presence of cystitis. The test reaction on the urine chemical reagent strip pad for nitrite works by detecting when nitrite in the urine reacts with para-arsanilic acid to form a diazonium compound. This diazonium compound in turn couples with 1,2,3,4-tetrahydrobenzo(h)quinoline-3-ol to produce a pink color.
Stenotrophomonas maltophilia and Burkholderia cepacia share each of the following EXCEPT for which characteristic? Please select the single best answer A. Decarboxylation of lysine B. Cytochrome oxidase activity C. Production of colonies with a yellow pigment D. Good growth on MacConkey agar
B Both Burkholderia cepacia and Stenotrophomonas maltophilia were previously included in the genus Pseudomonas. These were the two pasudomonads that produced yellow colonies and decarboxylated lysine. The departure of S. maltophilia from the genus was heralded by its lack of cytochrome oxidase activity. Most strains of B. cepacia are cytochrome oxidase positive, although the reaction may be weak in some cases. Of the characteristics listed, therefore, cytochrome oxidase activity is the only one that is different for the two species. Both of these species grow well on MacConkey agar.
Which of the following is/are NOT associated with immediate hypersensitivity? A. Hay fever B. Serum sickness C. Arthus reaction D. Anaphylactic shock E. Tuberculin reaction
B, C, and E; The tuberculin reaction is a type of delayed hypersensitivity reaction that appears 48-72 hours after antigen exposure, which is different from an immediate hypersensitivity response, which generally appears within 12 minutes of an antigen challenge. Arthus reactions and serum sickness are classified as a Type III hypersensitivty reactions involving the formation of immune complexes. The other choices above are all associated with immediate hypersensitivity reactions.
All of the following are characteristic findings in patients with iron deficiency anemia EXCEPT: Please select the single best answer A. microcytic, hypochromic red cell morphology B. decreased serum iron level C. decreased total iron-binding capacity (TIBC) D. decreased ferritin E. decreased hemoglobin
C. Iron deficiency anemia, or IDA, is associated with an increased TIBC as there is less iron to bind to transferrin. Microcytic, hypochromic red cell morphology, a decreased serum iron level, a decreased serum ferritin level, and a decreased hemoglobin level are all characteristics associated with IDA.
Skeletal deformations are most commonly present in which of the following beta thalassemias? Please select the single best answer A. Beta thalassemia minor B. Beta thalassemia intermedia C. Beta thalassemia major D. None of the beta thalassemias E. All of the beta thalassemias equally
C. Skeletal deformations result from the increased erythropoiesis that occurs in beta thalassemia major. Children with beta thalassemia intermedia may demonstrate some facial bone deformity, however this is not common. Beta thalassemia minor rarely causes any physical signs or symptoms and beta thalassemia minima is completely asymptomatic.
An aerobic gram negative coccobacillus was isolated from a nasopharyngeal swab 48 hours after culture from a 6 month old with the following culture characteristics on Bordet-Gengou agar: Small zones of beta-hemolysis Urease: positive Oxidase: negative Motility: negative The MOST probable identification of this isolate is: The correct answer is highlighted below A. Pasteurella multocida B. Bordetella pertussis C. Bordetella parapertussis D. Bordetella bronchiseptica
C. The clinical and laboratory findings most closely match that of a Bordetella species; particularly a Bordatella parapertussis infection. Bordetella pertussis is oxidase positive but urease negative, while B. parapertussis is oxidase negative and urease positive. B. bronchosepticus is positive for both enzymes.
The diffuse erythroderma and edema of the hand shown in the upper photograph of a 24 year old female with fever, headache and hypotension. The blood agar plate shown in the lower photograph was inoculated with purulent material aspirated from a vertebral disk abscess. The most likely condition is: The correct answer is highlighted below A. Scalded skin syndrome B. Scarlet fever C. Toxic shock syndrome D. Exfoliative erythroderma
C. The diffuse redness and subcutaneous swelling of the hand seen in the upper photograph is a hypersensitivity reaction to a foreign protein or toxin. The brief case history indicates that the patient is in the early stages of febrile shock. The blood agar plate shows large, opaque, white, beta hemolytic colonies most consistent with Staphylococcus species. These associations make toxic shock syndrome as the most likely condition, with the erythroderma secondary to reaction to the TSS-toxin-1. Similar skin reactions may be seen in scarlet fever, however, this condition is caused by a streptococcus and not a staphylococcus. Scalded skin syndrome and exfoliative erythroderma are also cutaneous hypersensitivity reactions to foreign proteins, but are manifest by the shedding of the epidermis in fine flakes or sheets, not seen in the upper photograph. However, either of these manifestations may be seen during the healing stages of erythroderma lesion seen here.
The black colonies growing on the surface of this cystine-tellurite agar plate, with black pigment diffusing into the surrounding medium, is one of the characteristics of Corynebacterium diphtheriae. Another closely related Corynebacterium species that may have a similar appearance on tellurite agar is: Please select the single best answer C. jeikeium C. pseudotuberculosis C. pseudodiphtheriticum C. ulcerans
C. ulcerans, closely related to C. diphtheriae both biochemically (differing only by failing to reduce nitrates or hydrolyze urea) and culturally (by producing the black colonies on tellurite agar as illustrated in the photograph), has recently nevertheless been given separate species status (Claridge and Spiegel, Manual Clinical Microbiology, 6th Edition, 1995, pgs 357-378). Some strains are further related by producing diphtheria toxin (Pers C, Acta Pathol Microbiol Immunol Scand 95:361-362, 1987).
Which of the following is TRUE of a fully compensated metabolic acidosis? Please select the single best answer A. pH will be decreased without a decrease in pCO2 B. pH will be decreased with a decrease in pCO2 C. pH will be decreased with an increase in pCO2 D. pH will be normal with a decrease in pCO2
D. The pH will be normal in a fully compensated form of any alkalosis or acidosis. In this case, the problem is metabolic, meaning there is a decrease in bicarbonate (alkaline) production which has reduced the pH of the blood. To compensate for this, the patient hyperventilates thus reducing the amount of acid, or pCO2 in the system to balance the pH into normal range.
Unexpected positive reactions encountered during forward ABO typing may be due to: Please select the single best answer A. A or B subgroups B. Antigen depression due to leukemia C. Hypogammaglobulinemia D. Acquired B antigen due to intestinal cancer
D. A and B subgroups, and antigen depression due to leukemia may cause unexpected negative reactions during forward typing. Hypogammaglobulinemia may cause an unexpected negative reaction during reverse typing. Acquired B antigen due to intestinal cancer is the only option listed that can cause an unexpected positive reaction during forward ABO typing.
Which one of the following statements about lead poisoning is false? Please select the single best answer A. While lead distributes to all tissues, the central nervous system, kidney, and bone marrow are particularly susceptible to lead toxicity B. Whole blood lead measurement is the best test for detecting lead toxicity C. Serum lead level is a good inexpensive screening test for lead toxicity D. Lead levels below 5 µg/dl in children do not prompt ongoing monitoring
D. Lead is a metal commonly found in the environment which can be very toxic. The use of lead varies widely in our society and until the 1970s not much attention was given to its toxicity, especially on the growth and development in children. Leaded gasoline, lead pipes, and lead paints have been removed from use in order to decrease human exposure. While lead distributes to all tissues, the central nervous system, kidney, and bone marrow are particularly susceptible to lead toxicity. Serum lead levels are of little value, since they fluctuate rapidly, and do not remain positive very long after episodes of exposure to lead. Whole blood lead measurement is the best test for detecting lead toxicity. The CDC recommends to monitor lead levels and if the upper limit is above 5 µg/dl in children to prompt ongoing monitoring. The goal is to keep levels below 10 µg/dl in children.
A two-year old male patient has the following hemogram results: Hgb = 6.7gms/dl Hct = 20% Platelets = 355,000/ mm3 RBC = 3.0mil/cmm WBC = 8750/cmm Differential = 6 eos 20 segs 68 lymphs 6 monos Which of the following is the MOST likely diagnosis? Please select the single best answer Dietary iron deficiency Idiopathic thrombocytopenia Lymphocytic leukemia Thalassemia minor Lead poisoning
Diet Iron Deficiency; We can rule out answer Idiopathic thrombocytopenia since the platelet count is normal. We can also exclude lymphocytic leukemia because the WBC is normal. Thalassemia minor can be excluded because thalassemia patients usually have only mild anemia. Finally, lead poisoning cannot be the answer since this condition does not usually cause severe anemia. The RBC, Hct, and Hgb are all very low, and this fits the picture of iron deficiency anemia.
Match the names of each of the bacterial species listed with the name of its associated virulence factor listed. 1. Enterococcus faecalis A. Lipoteichoic acids 2. Streptococcus pneumoniae B. Polysaccharide capsule 3. Streptococcus pyogenes C. M protein 4. Staphylococcus aureus D. Protein A
Enterococcus faecalis Lipoteichoic acids Streptococcus pneumoniae Polysaccharide capsule Streptococcus pyogenes M protein Staphylococcus aureus Protein A
Minimum inhibitory concentration (MIC) susceptibility tests should be performed against other beta lactam antibiotics on important S. pneumoniae isolates from blood cultures and other sterile body fluids when a MIC for penicillin is performed. Select true or false True False
False
Blood safety standards such as AABB Standards directly specify that an electronic crossmatch cannot be done when an Rh negative female has an anti-D consistent with antenatal RhIg administration. Select true or false True False
False; The statement is false. Current blood safety standards do not directly address whether an electronic crossmatch is contraindicated when anti-D consistent with antenatal RhIg administration is present. Laboratories are left to develop their own policies.
Which of the following is true about Bence-Jones protein when performing the heat precipitation test? Please select the single best answer A. Precipitates between 40° and 60°C but redissolves at 100°C B. Precipitates between 60° and 80°C but redissolves at 100°C C. Is dissolved between 40° and 60°C but precipitates around 100°C D. Is dissolved between 60° and 80°C but precipitates around 100°C
A. Bence-Jones proteins Precipitates between 40° and 60°C but redissolves at 100°C. The observation of this protein in the urine is most commonly linked to multiple myeloma or Waldenstrom's macroglobulinemia.
In essential thrombocythemia, the platelets are usually: The correct answer is highlighted below A. increased in number and functionally abnormal B. normal in number and functionally abnormal C. decreased in number and functional D. decreased in number and functionally abnormal
A. In essential thrombocythemia, or ET, platelet counts are usually greater than 600 x 109/L. In ET, it is common for these platelets to be functionally abnormal.
You are evaluating the effectiveness of a new, office-based rapid test for Influenza B. Among 1000 patients tested for Influenza B, 20 test positive using this rapid test, while 980 test negative. In reality, in addition to the 20 patients who tested positive, 10 more patients were also infected with influenza B, but tested negative when using this particular repid test. What is the sensitivity of the exam? What is the specificity? The correct answer is highlighted below A. Sensitivity = 66% and Specificity = 100% B. Sensitivity = 100% and Specificity = 75% C. Sensitivity = 66% and Specificity = 75% D. Sensitivity = 75% and Specificity = 2%
A. The correct answer is: Sensitivity = 66% and Specificity = 100%. This question is asking you to determine the sensitivity and specificity of this new, office-based rapid test for Influenza B. Thus, you really only need to know the values of 4 terms to answer the question. You need to know the values of True Positive, True Negative, False Positive and False Negative. There were 20 Truly Positive patients for Influenza B (number of individuals having the disease correctly identified by the test), while 970 were Truly Negative (number of individuals without the disease correctly identified by the test as negative). There were 0 Falsely Positive patients (number of nondiseased individuals incorrectly identified by the test as positive), but 10 patients were Falsely Negative (number of diseased individuals incorrectly identified by the test as negative). Thus: Sensitivity = True Positives/(True Positives + False Negatives) Sensitivity = 20/(20 + 10) = 66% Specificity = True Negatives/(True Negatives + False Positives) Specificity = 970/(970 + 0) = 100%
The reaction that occurs when a soluble antigen is mixed with its specific antibody is termed: A. Precipitation B. Agglutination C. Sensitization D. Fixation
A. The reaction that occurs when a soluble antigen is mixed with its specific antibody is termed precipitation. The visible precipitate is composed of large aggregates of antigen crosslinked by antibodies.
Review the descriptions of molecular testing techniques and select the correct statements. (Choose all that apply) More than one answer is correct. Please select all correct answers A. Renaturation is the process of converting double-stranded DNA to single strands B. Denaturation is the process of converting double-stranded DNA to single-stranded DNA C. Target amplification assays use methods to make more copies of a specific region of DNA D. In signal amplification methods, the target number increases as the signal is amplified
B & C Denaturation uses processes that make double-stranded DNA single-stranded. Molecular hybrids are fomed in hybridization methods; one strand is synthetic. Target amplification methods increase copies of target nucleic acid strands. In other amplification methods, target number is not changed; signal or probes are amplified.
Key characteristics by which Klebsiella pneumoniae can be suspected when an unknown member of the Enterobacteriaceae is recovered in primary culture include: More than one answer is correct. Please select all correct answers A. Indole production B. Absence of motility C. Failure to decarboxylate ornithine D. Positive phenylalanine deaminase
B and C Klebsiellapneumoniae is characteristically nonmotile, in contrast to other members of the Klebsiella, Enterobacter, Hafnia, Serratia group which are all motile. Also, a key reaction for the identification of Klebsiellapneumoniae in the API profile of tests is a negative ornithine decarboxylase, as most other members of this group produce a positive reaction. The indole reaction is not discriminatory for Klebsiella pneumoniae. A positive phenylalanine deaminase reaction is most helpful in distinguishing Proteus species and Providencia species from other members of the Enterobacteriaceae, and has no discriminatory value in distinguishing Klebsiellapneumoniae.
Codocytes (target cells) are a typical finding in which of the following types of beta thalassemia? More than one answer is correct. Please select all correct answers A. Beta thalassemia minima B. Beta thalassemia minor C. Beta thalassemia intermedia D. Beta thalassemia major
B-D; Normal red blood cell morphology is usually seen in the silent carrier form of beta thalassemia (minima). All other forms exhibit microcytosis, hypochromia, and codocytes (target cells) along with varying degrees of other abnormal RBC morphologies.
Each of the following bacterial species are commonly associated with wound infections following a dog bite except: A. Staphylococcus intermedius B. Bordetella bronchicanis C. Pasteurella multicida D. Capnocytophaga cyanodegmi
B. Although the species name of Bordetella bronchicanis (bronchiseptica) indicates an association with dogs ("canis"), the linkage is as an agent or respiratory tract infections in animals (tracheobronchitis or "kennel cough" in dogs, atrophic rhinitis in pigs, pneumonia and otitis media in rabbits and guinea pigs) (Ehrhardt M, et al: Bordetella bronchiseptica: pathogen vs commensal. Clin Microbiol Newslett 8:26-27, 1986). Although humans, particularly those who are immunosurppressed, may acquire B. bronchicanis respiratory infections by contact with dogs, wound infections following dog bites is not part of the clinical spectrum of this organism. In contrast, Staphylococcus intermedius, Pasteurella multicida and Capnocytophaga cyanodegmi are all known to be associated with dog bites, to the point that when one of these species is recovered, either from a wound or a blood culture, an animal source must be presumed.
A ficin (enzyme) treated panel can be a useful tool for determining the identity of an antibody. On a ficin-treated panel, reactions with _____ systems are enhanced, while reactions with _____ systems are degraded and reactions with ____ stay the same (unaffected). The correct answer is highlighted below A. (Rh, Kidd, Kell) (Lewis) (Duffy) B. (Rh, MN) (Duffy) (ABO) C. (Duffy) (Rh, Lewis, Kell) (Kell) D. (Rh, Lewis, Kidd) (MN, Duffy) (Kell)
D. The correct answer is: (Rh, Lewis, Kidd) (MN, Duffy) (Kell). Ficin treatment alters the surface of red blood cells such that interactions with Rh, Lewis and Kidd antibodies are enhanced; reactions with MN and Duffy are weakened; and reaction with Kell is unaffected.
