Infection of many people with known epidemiological link' is:

Correct Answer: C

Rationale: The correct answer is C: Epidemic. This term refers to the widespread occurrence of an infectious disease in a specific community or region at a particular time. In this scenario, the infection of many people with a known epidemiological link indicates a localized outbreak within a defined population. Explanation: 1. Epidemic specifically refers to a sudden increase in the number of cases of a disease above what is normally expected in a population. 2. The term "known epidemiological link" suggests a clear connection between the cases, indicating a common source or mode of transmission within a specific group. 3. Endemic (choice A) refers to the constant presence of a disease within a specific geographic area or population. 4. Pandemic (choice B) refers to a global outbreak of a disease that spreads across countries and continents. 5. Sporadic disease (choice D) refers to isolated cases that occur infrequently and without a clear pattern. In summary, an epidemic best describes the situation of many people being

Correct Answer: D

Rationale: The correct answer is D, chromoblastomycosis. This is a chronic localized subcutaneous infection caused by certain fungi, resulting in verrucoid lesions on the skin. The other choices are incorrect because: A: Candidiasis is a superficial fungal infection, not characterized by verrucoid lesions. B: Leprosy is a systemic bacterial infection, not localized to the skin with verrucoid lesions. C: Shingles is caused by the varicella-zoster virus, presenting as a painful rash with blisters, not verrucoid lesions.

Correct Answer: C

Rationale: The correct answer is C: leg swelling. Endocarditis is an infection of the inner lining of the heart chambers and valves. Symptoms typically include fever, chills, weight loss, and muscle aches due to the body's immune response to the infection. Leg swelling is not a common symptom of endocarditis. It may occur in conditions like heart failure but is not directly associated with endocarditis. Therefore, choice C is the correct answer. Choices A, B, and D are incorrect because fever and chills, weight loss, and muscle aches are commonly seen in endocarditis due to the systemic inflammatory response to the infection.

Correct Answer: C

Rationale: The correct answer is C because the main factor in the pathogenicity of diphtheria is the exotoxin produced by the bacterium Corynebacterium diphtheriae. This exotoxin inhibits protein synthesis in host cells, leading to tissue damage and the characteristic symptoms of diphtheria. A: The metachromatic bodies of Ernst-Babes are not the main factor in diphtheria pathogenicity. B: While endotoxins can contribute to the pathogenicity of some bacteria, in diphtheria, the main factor is the exotoxin. D: This is incorrect as the main factor in diphtheria pathogenicity is the exotoxin.

Correct Answer: A

Rationale: The correct answer is A: protein envelope around the nucleic acid. Viral capsid is the protein coat that surrounds and protects the viral nucleic acid (DNA or RNA). This structure helps in protecting the genetic material from degradation and facilitates the attachment of the virus to host cells. Option B is incorrect as it suggests the nucleic acid is coated with protein, which is not the case. Option C is incorrect as not all viruses have an outer membrane. Option D is incorrect as viruses typically do not have a lipoprotein membrane.

Correct Answer: C

Rationale: Rationale: 1. The male reproductive system is considered sterile as it does not have a natural microbiota. 2. Any presence of microorganisms in this system could indicate an infection or disease. 3. Therefore, choice C, sterile with no normal flora, is the best characterization. Summary: A: Incorrect - The male reproductive system does not typically have gram-positive rods. B: Incorrect - Acid-fast rods are not part of the normal flora in the male reproductive system. D: Incorrect - The male reproductive system does not typically have gram-positive spore formers.

Correct Answer: B

Rationale: The correct answer is B: psittacosis. Psittacosis is an infection caused by Chlamydia psittaci that primarily affects the lower respiratory tract, leading to pneumonia-like symptoms. Mycoplasma pneumoniae causes atypical pneumonia, not pharyngitis (Choice A). Chronic atrophic rhinitis (Choice C) and rhinoscleroma (Choice D) both affect the upper respiratory tract, not the lower respiratory tract. Psittacosis specifically targets the lower respiratory tract, making it the most appropriate answer.

Correct Answer: C

Rationale: The correct answer is C: Pili. Pili are bacterial structures involved in conjugation, which is the process of transferring genetic material between bacterial cells. Pili facilitate the physical contact between donor and recipient cells, allowing for the transfer of plasmids or other genetic material. Capsules (choice A) are involved in protection and adherence, not conjugation. Flagella (choice B) are responsible for bacterial motility. Fimbriae (choice D) are also involved in adherence but not in conjugation. Therefore, the correct answer is C as pili specifically play a crucial role in the process of conjugation.

Correct Answer: A

Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is a gram-negative bacilli that produce pyocyanin, a blue-green pigment. The presence of greenish fluorescent colonies of gram-negative nonsporeforming bacilli that release blue-green pigment matches the characteristics of Pseudomonas aeruginosa. Now, let's analyze the other choices: B: Enterobacteriaceae - While some Enterobacteriaceae can be gram-negative bacilli, they do not typically produce pyocyanin or exhibit the specific characteristics described in the question. C: Staphylococcus aureus - Staphylococcus aureus is a gram-positive cocci, not a gram-negative bacilli. It does not match the given description. D: Staphylococcus epidermidis - Staphylococcus epidermidis is also a gram-positive cocci, not a gram-negative bacilli. It does