On the 15-th day after a minor trauma of the right foot a patient felt malaise, fatigability, irritability, headache, high body temperature, feeling of compression, tension and muscular twitching of his right crus. What disease can it be?

Correct Answer: A

Rationale: The correct answer is A: Tetanus. Tetanus is caused by the bacterium Clostridium tetani, which produces a toxin affecting the nervous system. Symptoms such as malaise, irritability, muscular twitching, and high body temperature are characteristic of tetanus due to muscle spasms and rigidity. The 15-day incubation period after trauma aligns with the typical onset of tetanus symptoms. Incorrect choices: B: Anaerobic gas gangrene - This condition usually presents with localized tissue necrosis and gas bubbles in the affected area, not systemic symptoms like malaise and headache. C: Erysipelas - This is a bacterial skin infection presenting with red, swollen patches, not the neurological symptoms seen in tetanus. D: Acute thrombophlebitis - This is a blood clot in a vein causing pain and swelling, not associated with the systemic symptoms and muscle twitching seen in tetanus.

Correct Answer: D

Rationale: The correct answer is D: chemoheterotrophs. Chemoheterotrophs use organic compounds as both their carbon source and energy source. They obtain energy by breaking down organic molecules through cellular respiration. Photoautotrophs (A) use light energy to produce organic compounds, chemoautotrophs (B) use inorganic compounds for energy, and photoheterotrophs (C) use light energy but require organic compounds as a carbon source. Therefore, chemoheterotrophs best describe bacteria that obtain both carbon and energy from organic compounds.

Correct Answer: C

Rationale: The correct answer is C because both Clostridium botulinum and Bacillus anthracis are capable of forming spores to survive in extreme conditions. Clostridium botulinum is known for causing botulism and produces highly heat-resistant spores, while Bacillus anthracis is the causative agent of anthrax and also forms spores. Choice A is incorrect because only Clostridium botulinum is mentioned, not Bacillus anthracis. Choice B is incorrect because only Bacillus anthracis is mentioned, not Clostridium botulinum. Choice D is incorrect as it states that none of the bacteria can form spores, which is false based on the characteristics of Clostridium botulinum and Bacillus anthracis.

Correct Answer: D

Rationale: The correct answer is D (All of the above) because different bacteria can cause pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Mycobacterium tuberculosis causes tuberculosis, which can lead to pneumonia. Pseudomonas aeruginosa is a common cause of hospital-acquired pneumonia. Therefore, all three bacteria can be responsible for causing pneumonia in different contexts. Choices A, B, and C are incorrect because each bacterium individually can cause pneumonia, so selecting only one option would not cover the full spectrum of bacterial causes of pneumonia.

Correct Answer: C

Rationale: The correct answer is C (Both A and B) because both Bacillus anthracis and Clostridium botulinum are capable of forming spores to survive in harsh environments. Bacillus anthracis causes anthrax and forms spores that can survive extreme conditions. Clostridium botulinum causes botulism and also forms spores for survival. Option A (Bacillus anthracis) and Option B (Clostridium botulinum) are incorrect on their own because they only represent one of the bacteria capable of forming spores. Option D (None of the above) is incorrect because it disregards the fact that both bacteria can form spores.

Correct Answer: D

Rationale: The correct answer is D: lyases. Lyases are enzymes that catalyze the breaking of chemical bonds without the addition of water. They can remove functional groups from substrates or add functional groups to double bonds without the use of water. A: Oxidoreductases involve the transfer of electrons. B: Transferases transfer functional groups from one molecule to another. C: Hydrolases catalyze the breaking of bonds by adding water.

Correct Answer: B

Rationale: The correct answer is B: Passive hemagglutination. In this test, red blood cells coated with Treponema antigens agglutinate in the presence of patient's serum antibodies. This indicates the presence of antibodies against Treponema, confirming the diagnosis. A: Immobilization test uses live Treponema to detect specific antibodies, but it is not commonly used for syphilis diagnosis. C: Precipitation test is not commonly used for syphilis diagnosis. D: Complement binding test is not specific for syphilis and is used more for autoimmune diseases. Therefore, passive hemagglutination is the most appropriate serological test in this case due to its specificity and relevance to the presentation of the patient.

Correct Answer: A

Rationale: The correct answer is A: Entamoeba histolytica. This is because it is a protozoan parasite known to cause amoebic dysentery, presenting with chronic diarrhea and cysts with four nuclei in the stool sample. Giardia lamblia (B) causes giardiasis with trophozoites and cysts with two nuclei. Balantidium coli (C) is a ciliated parasite causing dysentery with large trophozoites. Trichomonas hominis (D) is a non-pathogenic flagellate often found in the human intestine. Thus, based on the specific characteristics of the cysts and clinical presentation, Entamoeba histolytica is the most likely causative agent.

Correct Answer: A

Rationale: The correct answer is A: Lice. Lice, specifically body lice (Pediculus humanus corporis), are known carriers of the pathogen Rickettsia prowazekii, which causes epidemic typhus. Body lice are commonly found in unsanitary conditions and can transmit the bacteria through their bites. Spiders (choice B), bed-bugs (choice C), and cockroaches (choice D) are not known vectors of epidemic typhus. Spiders are predators that do not transmit diseases to humans, while bed-bugs and cockroaches are associated with other health issues but not epidemic typhus transmission.