ATI RN
microbiology an introduction 13th edition test bank Questions
Question 1 of 9
Which bacteria is responsible for causing syphilis?
Correct Answer: A
Rationale: Step 1: Treponema pallidum is a spirochete bacterium known to cause syphilis, a sexually transmitted infection. Step 2: Neisseria gonorrhoeae causes gonorrhea, not syphilis. Step 3: Chlamydia trachomatis is responsible for causing chlamydia, not syphilis. Step 4: Escherichia coli is commonly found in the gut and can cause gastrointestinal infections, not syphilis. Summary: Treponema pallidum is the correct answer as it is the specific bacterium associated with syphilis, while the other choices are responsible for different infections.
Question 2 of 9
A patient suffering from syphilis was prescribed a drug the action of which based upon disturbed generation of murein leading to death of the causative agent. What drug is it?
Correct Answer: A
Rationale: The correct answer is A: Benzylpenicillin sodium salt. Benzylpenicillin is a beta-lactam antibiotic that inhibits the synthesis of bacterial cell walls by disrupting the formation of murein (peptidoglycan), leading to bacterial cell death. This mechanism specifically targets the causative agent of syphilis, Treponema pallidum. - Choice B: Bijochinol is not a known drug used to treat syphilis. - Choice C: Ciprofloxacin is a fluoroquinolone antibiotic that works by inhibiting bacterial DNA replication and is not the first-line treatment for syphilis. - Choice D: Azithromycin is a macrolide antibiotic that interferes with bacterial protein synthesis and is commonly used to treat other infections but is not the preferred treatment for syphilis.
Question 3 of 9
Which of the following infections is typical for the lower respiratory tract
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.
Question 4 of 9
Which one of the following is a risk factor on the part of the macroorganism for the development of an infectious disease?
Correct Answer: A
Rationale: The correct answer is A: Overcrowding. Overcrowding can facilitate the spread of infectious diseases due to increased contact between individuals, making it easier for pathogens to transmit from one person to another. This is a risk factor on the part of the macroorganism as it directly impacts the likelihood of disease transmission. Environmental pollution (B) may impact overall health but is not a direct risk factor for infectious diseases. Physical fatigue (C) weakens the immune system but is not a direct facilitator of disease transmission. Ionizing radiation (D) can cause cellular damage but is not a typical risk factor for infectious diseases.
Question 5 of 9
A 32-year-old patient who lives in the countryside consulted a doctor about a painful swelling and a fistula in the submandibular region. Examination revealed an infiltration with a fistula discharging thick pus and containing white granules. On dissection the infiltration tissues turned out to be dense, yellow-green and had honeycomb structure because of multiple abscesses. What is the most likely diagnosis?
Correct Answer: A
Rationale: The most likely diagnosis is Actinomycosis. This is because the patient's presentation of a painful swelling with a fistula containing white granules and yellow-green honeycomb-like tissue is classic for Actinomycosis. Actinomyces is a gram-positive anaerobic bacterium that forms sulfur granules in tissues. Tuberculosis (B) typically presents with caseating granulomas, not sulfur granules. Leprosy (C) presents with skin lesions and nerve damage, not characteristic of this case. Syphilis (D) usually presents with painless ulcers and rash, not the painful swelling and fistula seen in this patient.
Question 6 of 9
A wound culture grew Gram-positive rods with central spores. The bacteria were catalase-positive and aerobic. Identify the microorganism.
Correct Answer: A
Rationale: The correct answer is A: Bacillus anthracis. The presence of Gram-positive rods with central spores, catalase-positive, and aerobic growth characteristics are indicative of Bacillus anthracis. Bacillus anthracis is known for its central spores and ability to grow aerobically. Summary of why other choices are incorrect: B: Clostridium tetani is a Gram-positive rod with terminal spores and is anaerobic. C: Streptococcus pyogenes is a Gram-positive cocci and catalase-negative. D: Klebsiella pneumoniae is a Gram-negative rod and catalase-positive, but is not associated with central spores.
Question 7 of 9
A 70-year-old man was admitted to the hospital after suffering extensive third-degree burns. Three days later he spiked a fever and there was pus on the dressing that had blue-green colour. Gram stain of the pus revealed gram-negative rods. The most possible cause of these findings is:
Correct Answer: A
Rationale: The correct answer is A: The pyocyanin released by Pseudomonas aeruginosa. Pyocyanin is a blue-green pigment produced by Pseudomonas aeruginosa, a common cause of nosocomial infections in burn patients. The presence of blue-green pus and gram-negative rods in the wound along with fever suggests an infection with Pseudomonas aeruginosa. The other choices are incorrect because E. Coli typically causes gastrointestinal infections and releases enterotoxins, Staphylococcus aureus releases hemolysins causing hemolysis of red blood cells, and Shigella dysenteriae releases shigatoxin causing bloody diarrhea, none of which match the clinical presentation described in the question.
Question 8 of 9
A businessman came to India from South America. On examination the physician found that the patient was suffering from sleeping-sickness. What was the way of invasion?
Correct Answer: B
Rationale: The correct answer is B: As a result of mosquito's bites. Sleeping sickness, also known as African trypanosomiasis, is caused by the parasite Trypanosoma transmitted by tsetse flies, not mosquitoes. Tsetse flies are primarily found in Africa, not South America. Choice A is incorrect as bug bites do not transmit sleeping sickness. Choice C is incorrect as contaminated fruits and vegetables do not transmit the disease. Choice D is incorrect as dirty hands do not play a role in the transmission of sleeping sickness.
Question 9 of 9
Infections that may result from the use of catheters are classified as:
Correct Answer: A
Rationale: The correct answer is A: iatrogenic infections. Iatrogenic infections are those caused by medical interventions like catheter use. Catheters can introduce pathogens into the body, leading to infections. Local infections (B) refer to infections confined to a specific area, not necessarily caused by catheters. Exogenous infections (C) come from an external source, not specifically related to medical interventions. Endogenous infections (D) arise from the body's own flora and are not directly related to catheter use.