ATI RN
microbiology basic and clinical principles test bank Questions
Question 1 of 5
A fecal sample from a patient with diarrhea was cultured on Endo agar, resulting in colorless colonies. The bacteria were Gram-negative rods. What microorganism is most likely?
Correct Answer: B
Rationale: The correct answer is B: Shigella. On Endo agar, Shigella appears as colorless colonies due to its inability to ferment lactose. Shigella is a Gram-negative rod and is a common cause of diarrhea. Salmonella (A) and Escherichia coli (C) would typically produce pink colonies on Endo agar as they can ferment lactose. Proteus (D) is not commonly associated with diarrhea and would not be expected to grow on Endo agar.
Question 2 of 5
The virulence factors of bacteria include:
Correct Answer: B
Rationale: Rationale: The correct answer is B because virulence factors of bacteria are characteristics that enable them to cause disease. Colonization allows bacteria to establish and multiply in the host. Invasion refers to the ability to penetrate host tissues. Toxins are substances produced by bacteria that harm the host. Adhesion is crucial for bacteria to attach to host cells. A: Size and mutation are not typical virulence factors. Resistance is not directly related to causing disease. C: While toxins and evasion of body defenses are correct, motility and size are not universally considered virulence factors. D: Chemotaxis and fermentation are not primary virulence factors, unlike colonization and toxins.
Question 3 of 5
A source of hospital-acquired infection could be:
Correct Answer: D
Rationale: The correct answer is D because all the choices can contribute to hospital-acquired infections. New patients in the incubation period can spread infections, medical staff can inadvertently transmit infections, and contaminated medical instruments can also be a source of infections. Therefore, it is important to consider all these factors to prevent and control the spread of infections in a hospital setting.
Question 4 of 5
Name the halogen-containing antiseptic with fungicidal properties, which is used to treat dermatomycosis:
Correct Answer: A
Rationale: Rationale: 1. Iodine solution contains iodine, a halogen with antiseptic properties. 2. Iodine is effective against fungi, making it suitable for treating dermatomycosis. 3. Iodine solution is commonly used in dermatology for its fungicidal properties. 4. Formalin, methylene blue, and brilliant green do not contain halogens or have fungicidal properties. Summary: - Formalin is a disinfectant, not an antiseptic for dermatomycosis. - Methylene blue is an antifungal dye, not used as an antiseptic. - Brilliant green is an antiseptic, but does not contain halogens or have fungicidal properties.
Question 5 of 5
A 30-year-old patient complains about having abdominal pain and diarrhea for five days; body temperature rise up to 37, 5oC along with chills. The day before a patient had been in a forest and drunk from an open water reservoir. Laboratory analyses enabled to make the following diagnosis: amebic dysentery. What is the drug of choice for its treatment?
Correct Answer: A
Rationale: The correct answer is A: Metronidazole. Rationale: 1. Metronidazole is the drug of choice for amebic dysentery due to its effectiveness against the causative agent, Entamoeba histolytica. 2. Metronidazole has good tissue penetration and is able to reach the site of infection in the gut. 3. It is a bactericidal drug that acts by disrupting the DNA structure of the parasite. 4. Metronidazole is well-absorbed orally and has minimal side effects. Summary of other choices: B: Furazolidonum - Not the drug of choice for amebic dysentery. It is primarily used for treating bacterial diarrhea. C: Levomycetin - Not effective against Entamoeba histolytica and not recommended for amebic dysentery. D: Phthalazol - Not commonly used for amebic dysentery treatment. Metronidazole is preferred due