ATI RN
microbiology basic and clinical principles test bank Questions
Question 1 of 5
Which of the following methods can be used for diagnosis of respiratory tract infections
Correct Answer: D
Rationale: The correct answer is D: All are correct. Culture of samples from the respiratory tract can identify specific pathogens, Immunofluorescence can detect viral antigens, and PCR can amplify and detect specific DNA/RNA sequences. Using all methods together provides a comprehensive approach for diagnosing respiratory tract infections. Culture alone may miss fastidious organisms, Immunofluorescence has limitations in sensitivity, and PCR requires specific primers. Therefore, combining these methods increases the likelihood of accurate diagnosis by covering a range of pathogens and improving sensitivity and specificity.
Question 2 of 5
During latency, HSV1 exists in what form:
Correct Answer: B
Rationale: During latency, HSV1 exists as episomes in neurons. This is because HSV1 establishes a lifelong latent infection in sensory neurons, where the viral genome remains as a circular episome in the nucleus. This form allows the virus to persist in a dormant state, avoiding detection by the immune system. Choice A is incorrect as HSV1 does not integrate into the host chromosome. Choice C is incorrect as latency is a well-documented phenomenon for HSV1. Choice D is incorrect as the correct answer is B.
Question 3 of 5
A 25-year-old patient reports pain, burning at urination and scarce secretion in the morning. Urine samples are taken and cultivated on blood and MacConkey agar. After 24 hours of incubation, the culture are sterile. Which one of the following bacteria is the most probable cause of this disease?
Correct Answer: B
Rationale: The correct answer is B: Chlamydia trachomatis. This is because Chlamydia trachomatis is an obligate intracellular bacterium that cannot be cultured on standard agar plates. The symptoms described by the patient, such as pain, burning at urination, and scarce secretion in the morning, are indicative of a possible chlamydial infection. Additionally, the fact that the urine cultures are sterile after 24 hours of incubation suggests that the causative agent is not a typical bacteria like Escherichia coli, Streptococcus pneumoniae, or Neisseria gonorrhoeae, which would normally grow on agar plates. Therefore, Chlamydia trachomatis is the most probable cause of this disease. Summary: A: Escherichia coli - Incorrect, as it is a common cause of urinary tract infections and would typically grow on agar plates. C: Streptococcus pneumoniae - Incorrect, as it is
Question 4 of 5
The most common bacterial species in hospital environment is:
Correct Answer: B
Rationale: The correct answer is B: Staphylococcus aureus. This bacterium is commonly found in hospital environments due to its ability to colonize human skin and mucous membranes. It is a leading cause of hospital-acquired infections. Borrelia burgdorferi is mainly associated with Lyme disease transmitted by ticks, not commonly found in hospitals. Bacillus cereus is a foodborne pathogen, not typically prevalent in hospital settings. Staphylococcus haemolyticus is a coagulase-negative staphylococcus species, less pathogenic and less common in hospitals compared to Staphylococcus aureus.
Question 5 of 5
Etiological cause of bacteremia could be:
Correct Answer: D
Rationale: The correct answer is D because bacteremia can be caused by a variety of bacteria including S.epidermidis, E.coli, S.aureus, P.aeruginosa, K.pneumoniae, and resident skin diphtheroids. Bacteremia refers to the presence of bacteria in the bloodstream, which can occur due to infections from various sources. Choices A and B include common bacteria known to cause bacteremia, while choice C refers to resident skin diphtheroids that can also enter the bloodstream under certain conditions. Therefore, the correct answer is D as it encompasses all the possible etiological causes of bacteremia.