foundations in microbiology test bank

Correct Answer: A

Rationale: Rationale: 1. Corynebacterium diphtheriae is the correct answer as it is the bacteria responsible for causing diphtheria, characterized by a thick pseudomembrane in the throat. 2. Streptococcus pyogenes causes strep throat but does not produce a pseudomembrane. 3. Neisseria meningitidis causes meningitis and septicemia, not a throat pseudomembrane. 4. Bacillus cereus causes food poisoning, not throat-related symptoms.

Correct Answer: B

Rationale: The correct answer is B: Helicobacter pylori. This bacterium is responsible for stomach acid formation by producing an enzyme called urease, which converts urea into ammonia and carbon dioxide, leading to an increase in stomach pH. Staphylococcus aureus (A) does not cause stomach acid formation. Bacillus cereus (C) and Clostridium botulinum (D) are not involved in stomach acid processes.

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.

Correct Answer: B

Rationale: The correct answer is B: Campylobacter jejuni. This bacteria is commonly associated with foodborne illnesses due to its presence in undercooked poultry and unpasteurized milk. Campylobacteriosis is a leading cause of bacterial gastroenteritis. Streptococcus pneumoniae (A) causes pneumonia, not foodborne illnesses. Mycobacterium tuberculosis (C) causes tuberculosis, not foodborne illnesses. Haemophilus influenzae (D) can cause respiratory infections but is not commonly associated with foodborne illnesses.

Correct Answer: B

Rationale: The correct answer is B: K-antigen. H. Influenzae types are classified based on their capsular polysaccharides, which are known as K-antigens. The K-antigen is a major virulence factor and plays a crucial role in the pathogenicity of H. Influenzae. The other options (A, C, D) are not used to classify H. Influenzae types. Vi-antigen is related to Salmonella serotyping, O-antigen is characteristic of gram-negative bacteria such as Escherichia coli and Salmonella, and H-antigen is typically associated with flagellar antigens of bacteria like Salmonella and E. coli.