ATI RN
mcgraw hill microbiology test bank Questions
Question 1 of 5
Which of the following bacteria is responsible for causing the plague?
Correct Answer: A
Rationale: The correct answer is A: Yersinia pestis. Y. pestis is responsible for causing the plague, a severe infectious disease. This bacterium is transmitted via fleas from rodents to humans. It causes bubonic, septicemic, and pneumonic plague. Clostridium difficile causes gastrointestinal infections, Neisseria gonorrhoeae causes gonorrhea, and Pseudomonas aeruginosa can cause various infections but not the plague.
Question 2 of 5
Herpes simplex infections on lips and in the mouth are most commonly caused by:
Correct Answer: A
Rationale: The correct answer is A: HSV-1. Herpes simplex infections on lips and in the mouth are most commonly caused by HSV-1 due to its preference for infecting oral mucosa. HSV-2 typically causes genital herpes. HSV-6 and HSV-7 are less common and not typically associated with oral infections. Therefore, based on the typical presentation and epidemiology of herpes simplex infections, HSV-1 is the most likely cause in this scenario.
Question 3 of 5
4 days after a patient received a gunshot wound of the middle third of the thigh soft tissues his condition suddenly began deteriorating. There are complaints of bursting pain in the wound; pain increases during the last 12 hours. Edema of skin and hypodermic tissue quickly grows. Body temperature is 38,2oC, heart rate is 102/min. The wound edges gape, are dull in color; the muscles, viable as of day before, now protrude into the wound, look boiled, are dull in color, have dirty-grey coating and fall apart when being held with forceps. What infection has developed in the wound?
Correct Answer: A
Rationale: The correct answer is A: Anaerobic infection. The sudden deterioration, bursting pain, edema, foul appearance of wound, and presence of gas are indicative of gas gangrene caused by anaerobic bacteria like Clostridium perfringens. These bacteria thrive in low oxygen environments, such as deep wound tissues. The symptoms align with the classic presentation of gas gangrene, necessitating immediate surgical intervention. Choice B: Aerobic gram-negative, is incorrect because anaerobic bacteria, not aerobic gram-negative bacteria, are responsible for gas gangrene. Choice C: Putrid, is incorrect as it is a general term referring to foul-smelling decay and does not specify the type of infection. Choice D: Aerobic gram-positive, is incorrect as gas gangrene is typically caused by anaerobic bacteria, not aerobic gram-positive bacteria.
Question 4 of 5
The causative agent of the pertussis (also known as whooping cough) morphologically appears as:
Correct Answer: B
Rationale: The correct answer is B: Gram negative coccobacillus. Bordetella pertussis, the causative agent of pertussis, is a gram-negative coccobacillus. This is because it is a small, rod-shaped bacterium that appears both as a bacillus (rod-shaped) and a coccus (spherical) shape. It does not retain the crystal violet stain in the Gram staining process, indicating its negative gram nature. Choice A is incorrect because pertussis is not a gram-positive bacillus. Choice C is incorrect because pertussis is not a long gram-negative rod-shaped bacterium. Choice D is incorrect as the other options do not accurately describe the morphology of Bordetella pertussis.
Question 5 of 5
A 23 year old female patient complains about periodical chill and body temperature rise up to 40oC, sense of heat taking turns with profuse sweating. The patient has had already 3 attacks that came once in two days and lasted 12 hours. She has lived in Africa for the last 2 months. Liver and spleen are enlarged. In blood: erythrocytes - 2,5x1012/l. What is the most probable diagnosis?
Correct Answer: A
Rationale: The most probable diagnosis is A: Malaria. The patient's symptoms of periodic chills, high fever, and profuse sweating, along with living in Africa where malaria is endemic, strongly suggest malaria. The enlarged liver and spleen are consistent with malaria infection. The low erythrocyte count indicates hemolysis, a common feature of malaria. Spotted fever and sepsis do not typically present with the same pattern of symptoms and travel history as seen in this case. Haemolytic anaemia would not explain the patient's fever episodes and other symptoms. Therefore, based on the symptoms, travel history, and laboratory findings, malaria is the most likely diagnosis.