Mastering Microbiology Ch 23

Part I - Refine your hypothesis. Which of the following can best explain the symptoms and deterioration of your patient's husband?

Disseminated intravascular coagulation Endotoxic shock Gram-negative sepsis

Part H - Review possible diagnoses. What do you think is wrong with your patient's husband?

He has septicemic plague.

Which of the following is FALSE concerning Clostridium species?

Their main reservoir is rabbits

Which of the following can be transmitted from an infected mother to her fetus across the placenta?

cytomegalovirus

Epstein-Barr virus has been implicated in all of the following EXCEPT

endocarditis

Which of the following statements about schistosomiasis is FALSE?

it is caused by a roundworm

Which of the following pairs is mismatched?

Francisella gram-positive facultatively anaerobic pleomorphic bacillus

Which statement regarding the emerging viral hemorrhagic fevers is FALSE?

Later symptoms of hemorrhagic viral infection include low-grade fever and severe, crippling joint pains.

Part A - Infection John's physician said that he might be suffering from Chikungunya fever, an emerging disease that once was limited to Asia, Africa, and Europe, but is now making appearances in the Caribbean and the United States. How did John most likely get infected?

mosquito bite

Which of the following pairs is mismatched?

Pasteurella cat-scratch disease

The symptoms of gas gangrene are due to all of the following EXCEPT

endocarditis

Part C - Identify special conditions. "What is the matter?!" one of the doctors asks. You take another glance at your chart, and then respond that your patient could be infected with a disease that: Select one of the following answers in response to the doctor's question: is caused by an agent of bioterrorism is untreatable is hemorrhagic, and will likely progress to mortality very quickly indicates a source of infection within your hospital

is caused by an agent of bioterrorism

A patient returning from an extended trip into Mexico has the following symptoms: a papule at the site of a previous bug bite and enlarged lymph nodes. Microscopic examination of the papule reveals nucleated cells in white blood cells. The patient most likely has

leishmaniasis.

There are several different forms of the plague. Which form is of the greatest concern as a potential bioweapon?

pneumonic plague

Brucella bacteria are considered a potential agent of bioterrorism because

they easily become airborne.

John mentioned that while in the Caribbean, he had been very careful to wear bug spray when outside and to use a mosquito net around the bed at night. Why were these protective measures not enough to keep him from being infected?

Aedes mosquitoes prefer to live inside buildings, are more resistant to bug spray, and feed during the day.

The Big Picture Activity mentioned that because no vaccine is available, prevention is the next method for keeping the number of infections to a minimum. One of the methods recommended by the CDC is to prevent infected individuals from receiving mosquito bites during the first week of their infection. How does this help prevent further spread of infection?

Additional bites would increase the chances of an uninfected vector acquiring the virus.

Part E - Select a course of action. Since you suspect your patient could have the plague, you must confirm your diagnosis as soon as possible! Select the most appropriate samples to establish that you patient does or does not have the plague, and if these samples come back positive; which sort of plague.

Blood Fluid from your patient's inguinal swelling Sputum (mucus from lower airways)

Part complete Now that you have considered the evidence at hand, you should start to build a hypothesis about what disease your patient has. As you ponder her symptoms, you find yourself particularly troubled by her groin swelling. Groin (or inguinal) swellings can be a common symptom of a variety of sexually transmitted infections including herpes (genitalis and simplex), syphilis, chancroid, and lymphogranuloma venereum, among others. Your patient has been in a monogamous relationship for 6 years however, and does not report using any drugs of abuse. While it is still possible that your patient has contracted a sexually transmitted infection, you also would like to consider other disease possibilities. Select all conditions that could reasonably apply to your patient.

Cat-scratch disease Tularemia Plague Chagas' disease

Part K What sort of organisms would you instruct investigators to test for plague? Select all that apply.

Ground squirrels and rabbits Wild predators Rats and mice Household pets (cats and dogs)

Which of the following statements about toxoplasmosis is FALSE?

It is a severe illness in adults.

Which of the following statements about sepsis is FALSE?

It usually is caused by gram-negative bacteria.

As a child, Jamie suffered from rheumatic fever, which caused some major damage to one of her heart valves. She is OK, in general. However, she's been advised against getting body piercings, and her dentist gives her antibiotics before performing some dental procedures. What is the concern?

Jamie is more likely to develop subacute bacterial endocarditis.

Part J - Select a follow-up. You contact the New York City Department of Health and Mental Hygiene, as well the New Mexico Department of Health, and update them on the cases you have diagnosed. Both agencies are eager to locate where and how the infections were first contracted. Where will you recommend that investigators FIRST look for the source of infection? Select the BEST answer.

The couple's parent's ranch in New Mexico

Part G - Diagnose the causative organism. The stain of the cultured organisms from your patient's swollen lymph node reveals bipolar Gram-negative rods, with a "safety pin" appearance. Which organism is directly responsible for your patient's woes?

Yersinia pestis

Your laboratory results are shown here: Fluid Rapid diagnostics: (detection of F1 antigen by immunoflourescent assay) Culture Stain Blood negative negative Gram-stain: negative Aspirate from lymph node positive positive Gram-stain: positive Sputum negative negative Wayson stain: negative Does your patient have the plague? Can you say which form?

Yes, she has bubonic plague

Which of the following is a symptom of brucellosis?

undulant fever

A patient comes in with a possible Chikungunya infection. Rank the following in order. Drag and drop the steps below in the appropriate order from left to right.

uninfected mosquito feeds on an infected person replication of the virus inside the vector infected mosquito feeds on uninfected person patient has fever, headaches, and joint pain treatment with supportive therapy

Now that we have looked at ways to prevent breeding in mosquitos, another possible prevention is to limit the vector geographically, but recent climate changes have led to changes in location where the mosquito can now be found. Which of the following climate change scenarios has allowed for this increase in vector habitat?

warmer temperatures in northern regions with increased rainfall