What clinical specimen can be analysed in the diagnosis of sexually transmitted infections:

Correct Answer: D

Rationale: Certainly! The correct answer is D because all three options (A, B, and C) can be analyzed in the diagnosis of sexually transmitted infections. Genital ulcer secretions can reveal the presence of pathogens causing STIs, lymph node punctate can indicate systemic infection, and serum can be tested for specific STI antibodies. Therefore, all these clinical specimens are essential for a comprehensive diagnosis of sexually transmitted infections. The other choices (A, B, C) are incorrect as they individually represent important specimens used in the diagnosis process.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Filamentous spiral nucleocapsid is characteristic of Filoviridae, such as Ebola virus. 2. Linear unsegmented single strand (-) RNA is a key feature of Filoviridae genomes. 3. The lipid bilayer membrane of cellular origin is found in Filoviridae viruses. 4. Therefore, the correct answer is B (Filoviridae) due to the alignment of all three morphological features. Summary: - A (Picornaviridae): Has an icosahedral capsid, not filamentous spiral. - C (Orthomyxoviridae): Has a segmented genome, not linear unsegmented. - D (Togaviridae): Has a spherical capsid, not filamentous spiral.

Correct Answer: C

Rationale: The correct answer is C: Fungi. Molds are a type of fungi, which are eukaryotic organisms characterized by having cell walls made of chitin. Fungi are distinct from protozoans (single-celled eukaryotes), archaea (prokaryotes), and algae (photosynthetic eukaryotes). Fungi, including molds, obtain nutrients through absorption and play crucial roles in decomposition and nutrient cycling. Therefore, molds belong to the group of eukaryotic organisms known as fungi.

Correct Answer: A

Rationale: The correct answer is A: Spores. The Ozheshko method is used to stain spores, which are resistant structures produced by certain bacterial species. By studying the smear of streptobacillus preparation under oil immersion, one can observe the presence of spores as distinct, oval bodies within the bacteria. Spores are important for bacterial survival in harsh conditions. Summary: B: Capsules are not typically stained using the Ozheshko method. Capsules are usually visualized using negative staining techniques. C: Flagella are not stained by the Ozheshko method. Flagella are visualized using special staining techniques like the flagella stain. D: Inclusions are not specifically stained by the Ozheshko method. Inclusions are often observed using techniques that highlight cellular structures or components.

Correct Answer: C

Rationale: The correct answer is C because Marburg virus and Ebola virus belong to the Filoviridae family. These viruses are characterized by their filamentous shape and are known to cause severe hemorrhagic fever in humans. Both viruses have caused outbreaks with high mortality rates. Choice A (Lassa virus and lymphocytic choriomeningitis viruses) are not part of the Filoviridae family. They belong to the Arenaviridae family, which also includes viruses that cause hemorrhagic fevers. Choice B (Chikungunya virus and Sindbis virus) are arboviruses belonging to the Togaviridae family, which are not related to the Filoviridae family. Choice D (Crimean-Congo virus and Hantaan virus) are part of the Nairoviridae and Hantaviridae families, respectively, and not the Filoviridae family.

Correct Answer: A

Rationale: The correct answer is A: Tetanus. The patient's symptoms of muscle contractions, fever, and wound history suggest tetanus, caused by Clostridium tetani bacteria commonly found in soil. The spastic muscle contractions around the wound are classic for tetanus due to the neurotoxin produced by the bacteria. General weakness and headache are also common symptoms. B: Anthrax is unlikely as it presents with different symptoms such as skin lesions, respiratory symptoms, and gastrointestinal symptoms. C: Erysipelas is characterized by red, swollen patches on the skin, not consistent with the symptoms described. D: Gram-positive is not a specific diagnosis but a broad category of bacteria. Tetanus is caused by Clostridium tetani, which is a Gram-positive bacterium, but this choice does not provide a specific infection diagnosis.

Correct Answer: D

Rationale: The correct answer is D: Proteus vulgaris. This is because Proteus species are non-lactose-fermenting, Gram-negative rods that produce gas in nutrient broth. They are known to cause severe abdominal pain due to their ability to invade the intestinal mucosa. A: Salmonella enterica is a lactose-fermenting organism and typically does not produce gas in nutrient broth. B: Shigella dysenteriae is a lactose-negative organism but does not produce gas in nutrient broth. C: Escherichia coli is a lactose-fermenting organism and does not typically produce gas in nutrient broth. In summary, the presence of non-lactose-fermenting, gas-producing Gram-negative rods points towards Proteus vulgaris as the most likely causative agent of the severe abdominal pain.

Correct Answer: D

Rationale: The most probable diagnosis is D: Tularemia. Tularemia is a bacterial infection caused by Francisella tularensis. The symptoms described align with tularemia, such as pain in axillary area, fever, shaky gait, coated tongue, frequent pulse, painful lymphatic nodules, and erythematous skin over nodules. The key features pointing towards tularemia are the presence of lymphadenitis in the axillary area and the erythematous, glistering skin over the nodules, which are characteristic of ulceroglandular tularemia. Bubonic plague (A) presents with painful, swollen lymph nodes called buboes but typically lacks the erythematous skin findings. Acute purulent lymphadenitis (B) usually presents with pus-filled lymph nodes but does not typically cause shaky gait or coated tongue. Lymphogranulomatosis (C) is a term for Hodgkin's lymphoma, which does not

Correct Answer: A

Rationale: The correct answer is A: Obligate anaerobes. These bacteria can only survive in the absence of oxygen as they lack the enzymes needed for aerobic respiration. They typically use fermentation or anaerobic respiration for energy production. Incorrect choices: B: Facultative anaerobes can switch between aerobic and anaerobic metabolism based on oxygen availability. C: Obligate aerobes require oxygen for survival and cannot survive in anoxic conditions. D: Microaerophiles require low levels of oxygen for growth and are not capable of surviving in completely anoxic conditions.