During fibergastroscopy a patient with ulcer disease of the stomach, the mucosal biopsy is taken from the area of an ulcer. Impression smear is prepared from biopsy material and stained by Gram method; the rest of biopsy material is tested for urease activity. Microscopy of the impression smear revealed gram- negative spiral-shaped microorganisms, urease activity test is positive. What bacteria were detected?

Correct Answer: A

Rationale: The correct answer is A: Helicobacter pylori. Rationale: 1. Gram-negative spiral-shaped microorganisms match the morphology of Helicobacter pylori. 2. Positive urease activity is a characteristic feature of Helicjsonacter pylori. 3. Helicobacter pylori is specifically associated with gastric ulcers and is a common pathogen in the gastrointestinal tract. Summary: Choice B, Campilobacter jejuni, is a gram-negative curved bacterium but is not typically associated with gastric ulcers or urease activity. Choice C, Treponema pallidum, is a spirochete bacterium causing syphilis, which is not related to gastric ulcers. Choice D, Spirilla minor, is a generic term for spiral-shaped bacteria and is not a specific pathogen associated with gastric ulcers or urease activity.

Correct Answer: A

Rationale: The correct answer is A: 4 and 250. Coli index is calculated by dividing the number of red colonies by the volume of water analyzed, which gives 2 red colonies / 500 ml = 4. Coli titer is the reciprocal of the coli index, so it is 1 / 4 = 250. This indicates the concentration of coliform bacteria in the water sample. Choices B, C, and D are incorrect as they do not follow the correct calculation steps for determining the coli index and coli titer. B has the correct coli index but incorrect coli titer. C and D have the values reversed, leading to incorrect results.

Correct Answer: A

Rationale: Acyclovir is the correct answer because it is an antiviral drug used to treat herpes simplex and varicella-zoster viruses, not influenza. Tamiflu, Amantadine, and Relenza are used to treat influenza by inhibiting viral replication or easing symptoms. Acyclovir's mechanism of action targets different viruses, making it ineffective for treating influenza.

Correct Answer: D

Rationale: The correct answer is D because Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum are all known to cause non-gonococcal urethritis and cervicitis. These organisms can infect the urogenital tract and lead to inflammation and symptoms in both males and females. Each of these bacteria has been identified as a common cause of these conditions through research and clinical studies. Therefore, since all three organisms are capable of causing non-gonococcal urethritis and cervicitis, the correct answer is D. The other choices (A, B, and C) are incorrect because each of them alone can cause these conditions, making option D the most comprehensive and accurate choice.

Correct Answer: D

Rationale: The correct answer is D: PCR. PCR (Polymerase Chain Reaction) is the most suitable method for detecting genitourinary chlamydiosis due to its high sensitivity and specificity in detecting the genetic material of Chlamydia trachomatis. PCR can detect even low levels of the pathogen, providing accurate results. A: Cultural diagnostic is not as sensitive as PCR and may take longer to produce results. B: ELISA detects antibodies, which may not be present in early stages of infection, leading to false-negative results. C: CFT (Complement Fixation Test) is an older method with lower sensitivity compared to PCR for detecting chlamydiosis.