Nokea
Francisella tularensis is a:
- A. spore forming encapsulated gram-negative bacterium
- B. non-spore forming encapsulated gram-negative bacterium
- C. non-spore forming non-capsulated gram-negative bacterium
- D. spore forming non-capsulated gram-negative bacterium
Correct Answer: B
Rationale: The correct answer is B: non-spore forming encapsulated gram-negative bacterium. Francisella tularensis is a non-spore forming bacterium, which rules out choices A and D. It is encapsulated, which eliminates choice C. The encapsulation of the bacterium helps it evade the host immune system, leading to its pathogenicity. This encapsulated bacterium is responsible for causing the zoonotic disease tularemia in humans.
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Which of the following is commonly referred to as a pinworm?
- A. protozoans
- B. algae
- C. helminths
- D. fungi
Correct Answer: A
Rationale: The correct answer is A: protozoans. Pinworms are commonly referred to as Enterobius vermicularis, which are parasitic worms belonging to the phylum Nematoda. Protozoans are single-celled organisms, and pinworms are multicellular worms. Algae are photosynthetic organisms, helminths are parasitic worms (which pinworms fall under), and fungi are eukaryotic organisms that include molds and yeasts. Therefore, protozoans are the correct choice for organisms commonly referred to as pinworms.
What reaction is catalyzed by a beta-lactamase enzyme
- A. the final cross-linking reaction to form the bacterial cell wall
- B. the biosynthesis of the penicillin structure from the amino acid valine and cysteine
- C. the hydrolysis of the four-membered ring present in penicillin
- D. the hydrolysis of the acyl side chain from penicillin structures
Correct Answer: C
Rationale: The correct answer is C: the hydrolysis of the four-membered ring present in penicillin. Beta-lactamase enzyme catalyzes the hydrolysis of the four-membered beta-lactam ring present in penicillin, rendering the antibiotic ineffective against bacterial cell walls. This enzyme breaks the bond in the beta-lactam ring, thus inactivating the antibiotic.
Incorrect choices:
A: the final cross-linking reaction to form the bacterial cell wall - This is incorrect as beta-lactamase does not participate in the formation of bacterial cell walls.
B: the biosynthesis of the penicillin structure from the amino acid valine and cysteine - This is incorrect as beta-lactamase is not involved in the biosynthesis of penicillin.
D: the hydrolysis of the acyl side chain from penicillin structures - This is incorrect as beta-lactamase specifically targets the beta-lactam ring, not the
Almost half of all the STIs diagnosed in the United States are among:
- A. adolescents
- B. young adults
- C. young adults
- D. the elderly
Correct Answer: C
Rationale: The correct answer is C: young adults. Young adults are at a higher risk for sexually transmitted infections (STIs) due to factors such as engaging in risky sexual behaviors, lack of awareness, and inconsistent condom use. They are more likely to have multiple sexual partners and are less likely to seek regular STI screenings. Adolescents, while also at risk, may not make up almost half of all STI cases in the U.S. The elderly, on the other hand, are generally at a lower risk due to lower levels of sexual activity compared to young adults.
Rheumatic fever is an inflammatory disease and rare complication of:
- A. strep throat
- B. gangrene
- C. brucellosis
- D. tularemia
Correct Answer: A
Rationale: Rheumatic fever is caused by untreated strep throat. Step 1: Strep throat is caused by Streptococcus bacteria. Step 2: If strep throat is not treated with antibiotics, it may lead to rheumatic fever due to the body's immune response attacking its own tissues. Summary: Gangrene, brucellosis, and tularemia are not associated with rheumatic fever.
The bacteriological laboratory needs to prepare for analysis of materials that are suspected to be contaminated with spores of anthrax causative agent. What diagnostic preparation allows for quick detection of these spores?
- A. Anti-anthrax fluorescent serum
- B. Standard anthrax antigen
- C. Anti-anthrax immunoglobulin
- D. Monoclonal antibodies to anthrax causative agent
Correct Answer: D
Rationale: The correct answer is D: Monoclonal antibodies to anthrax causative agent. Monoclonal antibodies are highly specific for detecting anthrax spores, providing quick and accurate results. They bind only to the anthrax causative agent, allowing for precise identification.
Choice A (Anti-anthrax fluorescent serum) is incorrect because it is not as specific and sensitive as monoclonal antibodies.
Choice B (Standard anthrax antigen) is incorrect as it is used to stimulate antibody production in the body, not for direct detection of spores.
Choice C (Anti-anthrax immunoglobulin) is incorrect as it is a general term for antibodies and may not be specific to anthrax spores.
In summary, monoclonal antibodies are the most suitable option for quick and accurate detection of anthrax spores due to their high specificity and sensitivity.