Nokea
Elementary and reticular bodies are morphological?
- A. Mycoplasma genitalium
- B. Chlamydia trachomatis
- C. Rickettsia prowazekii
- D. None of the above
Correct Answer: B
Rationale: The correct answer is B: Chlamydia trachomatis. Elementary bodies (EBs) and reticular bodies (RBs) are two distinct forms of Chlamydia trachomatis, a bacterium causing various infections. EBs are the infectious form, while RBs are the replicative form within host cells. Mycoplasma genitalium (choice A) lacks a cell wall and does not have these specific morphological forms. Rickettsia prowazekii (choice C) is an obligate intracellular bacterium but does not exhibit the elementary and reticular body forms characteristic of Chlamydia trachomatis. Therefore, the correct answer is B, as only Chlamydia trachomatis exhibits the elementary and reticular bodies.
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A 32 year old patient complains about heartburn and dull pain in the epigastrium that appear 2-3 hours after meal. Exacerbations happen in spring and in autumn. The patient has food intolerance of eggs and fish. Objectively: stomach palpation reveals painfulness in the gastroduodenal area. Electrophasoduodenoscopy revealed a 5 mm ulcer on the anterior wall of duodenum. Urease test is positive. What is the most probable leading mechanism of disease development?
- A. Helicobacterial infection
- B. Dietary allergy
- C. Autoantibody production
- D. Reduced prostaglandin synthesis
Correct Answer: A
Rationale: The correct answer is A: Helicobacterial infection. This is the most probable leading mechanism of disease development in this case because the patient's symptoms, such as heartburn, epigastric pain, food intolerance, and presence of a duodenal ulcer with a positive urease test, are classic signs of Helicobacter pylori infection. This bacterium colonizes the stomach lining, leading to inflammation and ulcer formation. The exacerbations in spring and autumn could be due to seasonal variations in immune response.
Choice B: Dietary allergy is incorrect because the symptoms and findings in the patient are more indicative of an infectious etiology rather than an allergic reaction to specific foods.
Choice C: Autoantibody production is unlikely as there are no indications of an autoimmune process in this case.
Choice D: Reduced prostaglandin synthesis is not the leading mechanism as the symptoms and findings are more consistent with an infectious cause rather than a deficiency in prostaglandin synthesis.
Fires from flammable metals require type __________ fire extinguishers.
- A. A
- B. B
- C. C
- D. D
Correct Answer: D
Rationale: The correct answer is D because fires from flammable metals require specialized Class D fire extinguishers designed to extinguish these unique types of fires. Class A, B, and C fire extinguishers are not suitable for flammable metal fires as they are designed for different types of materials and fire classes. Class A extinguishers are for ordinary combustibles, Class B for flammable liquids, and Class C for electrical fires. Therefore, Class D fire extinguishers are specifically designed for flammable metal fires, making them the correct choice for this scenario.
Which of the following bacteria is known for producing a toxin that causes botulism?
- A. Clostridium botulinum
- B. Clostridium tetani
- C. Staphylococcus aureus
- D. Neisseria gonorrhoeae
Correct Answer: A
Rationale: The correct answer is A: Clostridium botulinum. This bacterium is known for producing botulinum toxin, which causes botulism. It is an anaerobic, spore-forming bacterium commonly found in soil. Clostridium tetani causes tetanus, not botulism. Staphylococcus aureus can cause food poisoning but not botulism. Neisseria gonorrhoeae is responsible for gonorrhea, not botulism. Therefore, A is the correct answer due to the specific association of Clostridium botulinum with botulism toxin production.
The bacteria that produces a thick pseudomembrane in the throat is:
- A. Corynebacterium diphtheriae
- B. Streptococcus pyogenes
- C. Neisseria meningitidis
- D. Bacillus cereus
Correct Answer: A
Rationale: Rationale:
1. Corynebacterium diphtheriae is the correct answer as it is the bacteria responsible for causing diphtheria, characterized by a thick pseudomembrane in the throat.
2. Streptococcus pyogenes causes strep throat but does not produce a pseudomembrane.
3. Neisseria meningitidis causes meningitis and septicemia, not a throat pseudomembrane.
4. Bacillus cereus causes food poisoning, not throat-related symptoms.
A journalist's body temperature has sharply increased in the morning three weeks after his mission in India, it was accompanied with shivering and bad headache. A few hours later the temperature decreased. The attacks began to repeat in a day. He was diagnosed with tropical malaria. What stage of development of Plasmodium is infective for anopheles-female?
- A. Gametocytes
- B. B.Shizontes
- C. C.Merozoites
- D. E.Sporozoites
Correct Answer: D
Rationale: The correct answer is D: Sporozoites. Sporozoites are the infective stage of Plasmodium for the female Anopheles mosquito. Here's the rationale: After being transmitted to a human host through a mosquito bite, the sporozoites travel to the liver where they mature and reproduce asexually as merozoites (not the infective stage for mosquitoes). The merozoites then infect red blood cells, leading to symptoms like fever, headache, and shivering. During the blood stage, some merozoites develop into male and female gametocytes, which are not infective to mosquitoes. When a mosquito bites an infected person, it ingests gametocytes, which then develop into male and female gametes and fuse to form ookinetes. Ookinetes develop into oocysts in the mosquito's gut, releasing sporozoites that migrate to the salivary glands, ready to infect a new human host when the mosquito bites