It is planned to use the territory of an old cattle burial ground (which is not used for more than 50 years) for building houses. But ground analysis revealed presence of the pathogen of the very dangerous illness. Which of the indicated microorgonisms is likely to remain in the ground for such a long time?

Correct Answer: C

Rationale: Rationale: 1. Bacillus anthracis is a spore-forming bacterium that can survive for decades in the soil. 2. The spores are resistant to harsh conditions and can remain dormant for long periods. 3. This resilience allows Bacillus anthracis to persist in the old cattle burial ground for over 50 years. 4. Mycobacterium bovis, Brucella abortus, and Francisella tularensis are not known for long-term survival in soil. Summary: - Mycobacterium bovis, Brucella abortus, and Francisella tularensis do not have the spore-forming ability. - Mycobacterium bovis causes tuberculosis in cattle. - Brucella abortus causes brucellosis in cattle. - Francisella tularensis causes tularemia in animals and humans.

Correct Answer: A

Rationale: Osmosis is the correct answer because it is the process by which water molecules move across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. This movement occurs passively, driven by the concentration gradient. Facilitated diffusion (B) involves the transport of specific molecules with the help of carrier proteins, not water. Phagocytosis (C) is a process where cells engulf solid particles, not water molecules. Exocytosis (D) is the process of releasing substances from a cell by fusion of vesicles with the cell membrane, not the transport of water across the membrane.

Correct Answer: A

Rationale: The correct answer is A: Fluconazole. 1. Fluconazole is an antifungal agent effective against Candida species commonly causing candidiasis. 2. Streptomycin (B) is an antibiotic used for bacterial infections, not fungal. 3. Phthalylsulfathiazole (C) is an antibacterial agent, not antifungal. 4. Ampicillin (D) is a β-lactam antibiotic, which can actually contribute to fungal infections like candidiasis.

Correct Answer: D

Rationale: The correct answer is D (All of the above) because all three bacteria (Clostridium botulinum, Escherichia coli, Salmonella enterica) are known to cause foodborne infections. Clostridium botulinum can lead to botulism, E. coli can cause various gastrointestinal illnesses, and Salmonella enterica is a common cause of food poisoning. Each bacterium has specific mechanisms that result in foodborne illnesses. Choices A, B, and C are incorrect because each bacterium mentioned is associated with causing foodborne infections, making them collectively the correct answer.

Correct Answer: C

Rationale: The correct answer is C because plasmids do not encode essential bacterial properties. They are non-essential, extra-chromosomal DNA molecules that can replicate independently within bacterial cells. Plasmids mainly contain genes for antibiotic resistance, genetic transfer, and other specific functions. Choice A is correct as many plasmids do carry antibiotic resistance genes. Choice B is also accurate as plasmids are indeed smaller, circular, and exist outside the bacterial chromosome. Choice D is true as plasmids can facilitate bacterial conjugation, allowing the transfer of genetic material between bacteria.

Correct Answer: A

Rationale: The correct answer is A: Syphilis. The presentation of painless inguinal lymph nodes, along with a small-sized ulcer with thickened edges and a "laquer" bottom of greyish color on the genital mucous membrane, is classic for primary syphilis. The painless nature of the lymph nodes and the specific characteristics of the ulcer are key features of syphilitic infection. Primary syphilis is caused by the bacterium Treponema pallidum and typically presents with a single, painless ulcer known as a chancre. It is important to consider syphilis in the differential diagnosis of genital ulcers. Summary of other choices: B: Tuberculosis - Unlikely, as tuberculosis typically presents with pulmonary symptoms and does not cause genital ulcers. C: Lepra - Unlikely, as leprosy does not typically present with painless inguinal lymph nodes and the specific ulcer characteristics described. D: Trophic ulcer - Unlikely

Correct Answer: C

Rationale: Rationale: 1. Bacillus anthracis is a spore-forming bacterium that can survive for decades in the soil. 2. The spores are resistant to harsh conditions and can remain dormant for long periods. 3. This resilience allows Bacillus anthracis to persist in the old cattle burial ground for over 50 years. 4. Mycobacterium bovis, Brucella abortus, and Francisella tularensis are not known for long-term survival in soil. Summary: - Mycobacterium bovis, Brucella abortus, and Francisella tularensis do not have the spore-forming ability. - Mycobacterium bovis causes tuberculosis in cattle. - Brucella abortus causes brucellosis in cattle. - Francisella tularensis causes tularemia in animals and humans.

Correct Answer: B

Rationale: The correct answer is B: EIEC. This strain of E. coli can cause bloody diarrhea in children similar to shigellosis due to its ability to invade and replicate within the intestinal epithelial cells, leading to inflammation and bloody stools. ETEC (A) causes watery diarrhea due to enterotoxins. EAEC (C) causes persistent diarrhea. EPEC (D) causes attaching and effacing lesions on the intestinal mucosa without invasion.

Correct Answer: A

Rationale: Rationale: Metronidazole is the drug of choice for treating lambliosis due to its effectiveness against Giardia lamblia, the parasite causing the infection. Metronidazole works by disrupting the DNA structure of the parasite, leading to its death. Erythromycin (choice B) is not effective against Giardia lamblia. Monomycin (choice C) and Chingamin (choice D) are not commonly used for treating lambliosis. Therefore, choice A, Metronidazole, is the correct medication for this patient.