MICRO mastering infectious diseases
What is one of the virulence factors associated with the causative agent for this infection?
erythrogenic toxin
Papillomas are typically spread through direct contact infected humans or __________.
fomites
Many strains of HPV are _____ and can integrate into human chromosomes.
latent
A pathogen that has chitin in its cell wall would also have _________.
ergosterol
What term is associated with warts found on face?
Flat warts
Why is necrotizing fasciitis so difficult to prevent?
It is part of the normal microbiota.
What disease does Paul suspect Ron might have contracted?
Rocky Mountain spotted fever
Into which type of cell are the Rickettsia introduced in the human host?
Endothelial cells
What type of pathogen causes papillomas?
viruses
Which of the following symptoms is LEAST characteristic of Clostridium perfringens food poisoning?
moderate vomiting and fever
The following can be distinguished by their cell wall structure ____ and _____ .
mycobacterium tuberculosis coccidioides immitis
The following can be distinguished by their rRNA sequence: ____ , _____ , and ______ .
mycobacterium tuberculosis legionella pneumophila coccidioides immitis
Which is the vector of Rickettsia rickettsia?
a tick
Warts may disappear over time without treatment. This is due to __________.
the body's cell-mediated immunity
What is the attack rate of food poisoning among the group who attended the July 4 celebration?
105/150(100)= 70.0%
What percent of patients are estimated to die from the disease?
20%
Rickettsia rickettsii is a gram-negative, obligate intracellular pathogen. Which of the following statements about the R. rickettsii life cycle is FALSE?
After entering a host, R. rickettsii multiplies to levels high enough to successfully invade cells and establish an infection.
Students identified RSV and influenza as possible causes of Uncle Luis' lung infection. In terms of characteristics used to classify viruses, what distinguishes these two viruses?
Genome structure
An indirect immunofluorescence assay is described as the CDC "gold standard serological test" for RMSF. Keeping in mind the principles behind indirect fluorescent-antibody (indirect FA) testing, which of the following characteristics contributes to its choice as the gold standard?
Indirect FA is rapid, sensitive, and specific. Indirect FA uses an antibody that reacts with any human antibody. Indirect FA will detect R. rickettsii-specific antibodies present in the patient's serum. Indirect FA is more sensitive than direct immunofluorescent testing.
Some of the individuals who said they ate the barbecue with the sauce did not become ill. Which one of the following is the most likely explanation for such an occurrence?
Individuals who became ill may have consumed larger quantities of the food than individuals who did not become ill.
The following can be identified using a Gram stain:_______.
Legionella pneumophila
__________ is an antiphagocytic factor and helps S. pyogenes attach to nose and throat cells.
M protein
A person has a suspected lung infection. A sputum sample is Gram stained, but no bacteria are visible. However, bacterial colonies do grow after a prolonged incubation. The patient is successfully treated with an antibiotic regimen that includes isoniazid. Why were no bacteria visible after the initial staining reaction?
Mycolic acids in the wall of this pathogen resist uptake of the Gram stain.
Which of the following is a characteristic of biological transmission from Dermacentor to a human host?
R. rickettsii is transmitted to the human host during a bite, when tick saliva enters the wound.
The following can be distinguished by their genome structure and composition:_____ and _____.
Respiratory syncytial virus influenza virus
Infections with these symptoms are generally caused by which of the following pathogens?
Streptococcus pyogenes
Which of the following bacteria is the primary cause of necrotizing fasciitis?
Streptococcus pyogenes
What area of the country has the highest incidence of Rocky Mountain Spotted Fever?
The Appalachian mountains and Ozarks
How is the dormant form of Rickettsia rickettsii activated?
The bacteria are activated after the tick feeds on a host for several hours.
The IV regimen administered by Ron's doctors is consistent with the CDC's recommendation that doxycycline be administered when RMSF is suspected. Apply your knowledge of RMSF to choose the most likely reasons behind this recommendation.
The symptoms of RMSF are similar to those of several other infections, making definitive diagnosis difficult. Most tests that can definitively identify R. rickettsii are not very effective early in infection. A delay in treatment can lead to complications that include respiratory, cardiac, and renal failure. Without prompt treatment, RMSF can have a mortality rate as high as 20%.
Which might be the best way to prevent getting infected by Rickettsia rickettsia?
Use tick repellants and remove ticks quickly.
Based on the observations given, what is the probable diagnosis made by the health care provider?
erysipelas
A drug targets chitin. Which type of pathogen should this drug be effective against?
fungi
A characteristic symptom of necrotizing fasciitis is that the pain __________.
is disproportionate to the appearance of the infection
The nutritional requirement to oxidize amino acids and Kreb's cycle intermediates means Rickettsias are __________.
obligate intracellular parasites
What should the course of treatments for this infection entail?
oral antibiotics
In 90% of cases, a spotted non-itchy rash forms on the __________, particular to rickettsiosis.
palms and soles
One of the virulence factors produced by Group A Streptococcus is __________, which can kill neutrophils, the immune system's first responders.
streptolysin S
What part of the United States is endemic for RMSF?
the Appalachian region (North Carolina, Kentucky)
A chief concern of the health care provider with an infection such as this one would be which of the following?
the bacteria spreading to the blood (bacteremia) and damaging the heart or the kidneys