Nokea
Which statement about leptospirosis is INCORRECT:
- A. Leptospirosis is acute infectious disease with typical geographic distribution
- B. Reservoirs of leptospira are different wild and domestic animals-mainly rodents
- C. Leptospira can be cultivated on blood and chocolate agar
- D. doxycycline and penicillins are drugs of choice for treatment of leptospirosis
Correct Answer: C
Rationale: The correct answer is C because Leptospira cannot be cultivated on blood and chocolate agar. The bacterium requires specialized media such as Ellinghausen-McCullough-Johnson-Harris (EMJH) medium for growth. Blood and chocolate agar do not provide the necessary nutrients for the bacterium's growth. Leptospira is a fastidious organism that has unique culture requirements. Therefore, the statement that Leptospira can be cultivated on blood and chocolate agar is incorrect. The other choices are correct: A - Leptospirosis is an acute infectious disease with a typical geographic distribution, B - Reservoirs of leptospira are different wild and domestic animals, mainly rodents, and D - Doxycycline and penicillins are drugs of choice for the treatment of leptospirosis.
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Laboratory diagnosis of Rotavirus infection includes
- A. Egg inoculation
- B. Sensitive laboratory animals
- C. Ascoli test
- D. Cell cultures
Correct Answer: D
Rationale: The correct answer is D: Cell cultures. Rotavirus diagnosis involves detecting viral antigens in stool samples using cell cultures. Cell cultures allow for the replication of the virus, facilitating its identification. A: Egg inoculation and B: Sensitive laboratory animals are not commonly used for Rotavirus diagnosis due to ethical concerns and practical limitations. C: Ascoli test is used for detecting specific proteins in serum, not for Rotavirus detection in stool samples. In summary, cell cultures are the most appropriate method for laboratory diagnosis of Rotavirus infection due to their ability to support viral replication and antigen detection.
Which bacteria are associated with the disease tuberculosis?
- A. Mycobacterium leprae
- B. Mycobacterium tuberculosis
- C. Streptococcus pneumoniae
- D. Escherichia coli
Correct Answer: B
Rationale: The correct answer is B: Mycobacterium tuberculosis. This bacterium is specifically associated with causing tuberculosis. Mycobacterium leprae (choice A) is associated with leprosy, not tuberculosis. Streptococcus pneumoniae (choice C) is associated with pneumonia, not tuberculosis. Escherichia coli (choice D) is a common bacterium found in the intestines and is not associated with tuberculosis. Mycobacterium tuberculosis is the only bacterium directly linked to the disease, making it the correct choice.
The tool of choice to observe living microorganisms is the
- A. bright-field microscope
- B. phase-contrast microscope
- C. fluorescence microscope
- D. electron microscope
Correct Answer: B
Rationale: The correct answer is B: phase-contrast microscope. This type of microscope is ideal for observing living microorganisms because it enhances the contrast of transparent specimens without the need for staining or fixing, allowing for clear visualization of internal structures and movements. Bright-field microscopes (A) are suitable for observing fixed and stained specimens, not living organisms. Fluorescence microscopes (C) are used to detect specific cellular components tagged with fluorescent markers, not ideal for observing overall morphology. Electron microscopes (D) use electron beams and are best for viewing detailed structures at high magnification, but are not suitable for observing living organisms due to the need for vacuum conditions.
A man is ill with a protozoan disease characterized by cerebral affection and loss of sight. Blood analysis revealed halfmoon-shaped unicellular organisms with pointed ends. This disease is caused by:
- A. Toxoplasma B.Leishmania C.Lamblia D.Amoeba E.Trichomonad
Correct Answer: A
Rationale: The correct answer is A: Toxoplasma. Toxoplasma gondii causes Toxoplasmosis, a protozoan disease that can affect the brain and lead to vision loss. The halfmoon-shaped unicellular organisms with pointed ends described in the blood analysis are characteristic of Toxoplasma parasites. Toxoplasma infection commonly occurs through ingestion of contaminated food or water, or contact with infected cat feces. Leishmania causes Leishmaniasis, Lamblia causes Giardiasis, Amoeba causes Amebiasis, and Trichomonad causes Trichomoniasis, none of which match the symptoms and blood analysis findings described in the question.
Anti-tetanus gamma globulin is produced by hyperimmunization of donors with tetanus anatoxin. What class of immunoglobulins prevails in this preparation?
- A. IgG
- B. IgA
- C. IgM
- D. IgE
Correct Answer: A
Rationale: The correct answer is A: IgG. Anti-tetanus gamma globulin is produced by hyperimmunization, leading to a high concentration of specific antibodies, predominantly IgG. IgG is the most abundant immunoglobulin in the blood and provides long-term immunity against tetanus. IgA is mainly found in mucosal areas, not in gamma globulin preparations. IgM is the first antibody produced in response to an infection and is not the prevailing class in this preparation. IgE is associated with allergic reactions and parasitic infections, not with anti-tetanus immunity.