A patient who has been taking tetracycline for a long time has developed candidosis of mucous membranes. What drug shoul administered for its treatment?

Correct Answer: A

Rationale: The correct answer is A: Itraconazole. Itraconazole is an antifungal medication commonly used to treat candidosis. It works by inhibiting the synthesis of ergosterol, a key component of fungal cell membranes. This action disrupts the integrity of the fungal cell membrane, leading to cell death. Griseofulvin (B) is primarily used to treat fungal infections of the skin and nails, not mucous membranes. Nitrofungin (C) is not commonly used for candidosis treatment. Amphotericin (D) is a potent antifungal medication but is typically reserved for severe or systemic fungal infections due to its potential side effects.

Correct Answer: A

Rationale: Ribosomes are responsible for protein synthesis, where they translate the genetic information from mRNA into specific amino acid sequences to form proteins. This process occurs in both prokaryotic and eukaryotic cells. Ribosomes do not participate in the breakdown of substances, which is mainly carried out by lysosomes or proteasomes. Oxidative phosphorylation involves the generation of ATP in mitochondria, not ribosomes. Ribosomes do not inactivate antibiotics; this is typically done by enzymes or chemical modifications. Therefore, the correct answer is A as ribosomes play a crucial role in protein synthesis.

Correct Answer: A

Rationale: The correct serological test for diagnosing toxoplasmosis is the Complement Binding Assay (A) because it detects antibodies specific to the Toxoplasma gondii parasite. This test is highly sensitive and specific for toxoplasmosis. Choice B, Precipitation test, is not used for toxoplasmosis diagnosis but rather for other diseases like syphilis. Choice C, Neutralization test, is not specific for toxoplasmosis and is used for other types of infections. Choice D, Widal's test, is used for diagnosing typhoid fever and is not relevant for toxoplasmosis. In summary, the correct answer (A) is specific to toxoplasmosis, while the other choices are used for different diseases and are not suitable for diagnosing toxoplasmosis.

Correct Answer: A

Rationale: The correct answer is A: Syphilis. Hutchinson's triad is a classic presentation of congenital syphilis in children. Barrel-shaped incisors, parenchymatous keratitis, and deafness are key manifestations. Barrel-shaped incisors result from mulberry molars, a type of abnormal tooth. Parenchymatous keratitis is an inflammation of the cornea, a common ocular sign in congenital syphilis. Deafness can occur due to damage to the auditory nerve caused by the infection. Choices B, C, and D are incorrect as they do not typically present with the specific triad of symptoms seen in congenital syphilis.

Correct Answer: C

Rationale: The correct answer is C: Thermophiles. Thermophiles are bacteria that thrive in high temperatures, typically between 45-80 degrees Celsius. They have adapted to extreme heat environments and have enzymes that function optimally at high temperatures. Mesophiles (A) grow best at moderate temperatures, Psychrophiles (B) thrive in cold temperatures, and Halophiles (D) thrive in high salt concentrations. Therefore, only Thermophiles are specifically adapted to high temperatures, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Gram-positive rod-shaped bacteria. Listeria monocytogenes is a Gram-positive bacterium, as it retains the crystal violet stain during the Gram staining process. The bacteria are rod-shaped, not spherical. Choice A is incorrect as Listeria monocytogenes is not Gram-negative. Choice D is incorrect as Listeria monocytogenes does fall under the category of Gram-positive bacteria. The key is to remember the characteristics of Listeria monocytogenes, which are Gram-positive and rod-shaped.

Correct Answer: D

Rationale: The correct answer is D: simple diffusion. In simple diffusion, molecules move from an area of high concentration to low concentration without the need for energy input. Hydrostatic pressure is a form of passive transport that drives molecules to equalize concentration. Filtration (A) involves the movement of solutes through a membrane under pressure. Exocytosis (B) is the process by which cells release substances outside the cell using energy. Osmosis (C) is the movement of water molecules across a selectively permeable membrane. Therefore, simple diffusion is the most appropriate choice in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Clostridium perfringens. Clostridium perfringens is a gram-positive spore-forming bacillus commonly found in soil. It produces hemolysis on blood agar, as described in the question. Clostridium botulinum is also a gram-positive spore-forming bacillus, but it does not typically cause hemolysis. Staphylococcus aureus is a gram-positive cocci, not a bacillus. Pseudomonas aeruginosa is a gram-negative bacterium, not a gram-positive spore-forming bacillus.

Correct Answer: A

Rationale: The correct answer is A: Clostridium botulinum and Clostridium tetani. Both bacteria produce exotoxins that affect the nervous system. Clostridium botulinum produces botulinum toxin, causing botulism, leading to muscle paralysis. Clostridium tetani produces tetanospasmin, causing tetanus, leading to muscle stiffness and spasms. Choice B (Escherichia coli and Salmonella) are known for causing gastrointestinal infections, not specifically affecting the nervous system. Choice C (Bacillus anthracis and Listeria monocytogenes) produce toxins that primarily affect other body systems, not the nervous system. Choice D (Pseudomonas aeruginosa and Staphylococcus aureus) are associated with skin and respiratory infections, not neurological effects.