It is extremely difficult to eradicate staphylococcal infection in the presence of a foreign body. Thus infected artificial joints and infected intravenous lines often must be removed in conjunction with optimal intravenous anti-staphylococcal therapy with oxacillin or nafcillin (sometimes in combination with rifampin) in order to eradicate such staphylococcal infections (and these attempts are not always successful). Staphylococcal infection of bone may persist for many years despite what should be optimal antimicrobial therapy. The most likely reason for this tenacity of staphylococcal osteomyelitis is: A. The Staphylococcal pilus gene is up-regulated by oxacillin B. Fragments of dead bone called involucrum may act as a foreign body and may have to be removed for optimal eradication of the staphylococcal infection. C. Staphylococci may be perceived by the patient’s immune system as a positive factor because the staphylococci produce an extracellular enzyme obtundokinase which makes the patient more alert. D. Staphylococci are such an integral part of our normal flora that they are treated as self rather than non-self and no immune reaction to them occurs.
Organism to be causing septicemia depends among other things on the patients’ personal risk factors.
he most likely organism to be causing septicemia depends among other things on the patients’ personal risk factors (e.g. their underlying disease) or lab data (e.g. their leukocyte count) community risk factors (such as what particular organisms inhabit the unit on which they happen to be in the hospital); and the physical examination. In a bone marrow transplant patient with a fever of 104 F who has a white blood cell count of 345/mm3 there are scattered skin lesions comprised of a central blue area with an areola of redness (inflammation). You vaguely remember seeing such a lesion before in a lecture. Ecthyma something or the other is the best you can do… Oh yes with the blue gangrene-like center ecthyma gangrenosum that’s it is your mental conversation. In this patient the most likely organism is: A. Reimerbacterium deaniium B. Pseudomonas aeruginosa C. Flavobacterium aniseum D. Godzillobacterium resistium
The diagnosis of septicemia should be considered in patients who are at increased risk of blood stream infection (often secondary to local disease such as urinary tract infection or pneumonia). All of the following are factors predisposing patients to septicemia except: A. Underlying diseases that appear to compromise host defenses such as diabetes lymphoma etc. B. Patients with a polymorphonuclear leukocyte count less than 1000/mm3 C. Patients with polymorphonuclear leukocyte counts of 10 000 to 20 000 D. Long term therapy with broad-spectrum antimicrobials.
On physical examination he is afebrile has a rather ruddy complexion and his pupils are dilated and fixed.
A 13 year old boy appears in your emergency room complaining of blurred vision and a dry mouth. His companions say that he has been muttering about a white condor that is going to pick him up and take him to a mountain top. He was a member of a scout troop that has been hiking and camping in the Capitol Reef area of Utah. On physical examination he is afebrile has a rather ruddy complexion and his pupils are dilated and fixed. He adamantly denies eating any canned food or processed meat but confesses that on a dare he ate a large trumpet-like white flower that his patrol members brought back from a hike in the desert. The most likely explanation for his illness is: A. A food-borne infection with E. coli 0157:H7 B. Ingestion of Datura stramonium with a resulting anticholinergic and hallucinogenic reaction C. He has a malignant brain tumor D. He has been bitten by a brown recluse spider
Further in the last ten hours the sore throat has been accompanied by a headache as well as nausea and vomiting.
A 22 year old female graduate student who works in a day-care center comes to the emergency room where you are on duty. The woman complains of a sore throat which she has had for two days and it is not getting any better; further in the last ten hours the sore throat has been accompanied by a headache as well as nausea and vomiting. On physical examination you note a BP of 90/65 and a respiratory rate of 30/min; the temperature is 104 degrees F. The neck is supple but there are tiny red spots distal to the BP cuff. Considering this patient’s personal risk factors (her age) and her physical examination it is clear that the most likely organism to be causing this patient’s illness is: A. Brucella abortus B. Staphylococcus aureus C. Neisseria meningitidis D. Brucella suis
Complaining of shaking chills and fever went to the Salt Lake City Homeless clinic. She had enlarged lymph nodes in the right axilla.
A 42 year old woman who was complaining of shaking chills and fever went to the Salt Lake City Homeless clinic. She had enlarged lymph nodes in the right axilla. Upstream from the enlarged nodes was an ulcer on the top of the patient’s right hand. When carefully questioned the patient said she remembered being bitten there by an insect resembling a horsefly but with yellow stripes on its abdomen; Its what we used to call a deerfly she added laconically. The patient denied any contact with rats or fleas. The patient’s disease was most likely to be: A. Brucellosis B. Ulcero-glandular tularemia C. Pneumonic plague D. Relapsing fever
As a budding basic scientist you work in a research laboratory and discover a chemical that removes the cell wall from bacteria but leaves the organism undamaged otherwise. Things that the bacteria will lose because of this include: A. The ability to stain gram positive: all will look gram negative B. The ability to move C. The ability to have a gram stain result D. The ability to attach to other cells
A 25 year old woman has a 4 year old son who is now recovering from Group A strep pharyngitis. Out of curiosity the pediatrician does a throat culture on the mother which is positive for Group A strep even though she doesn’t have a sore throat. The pediatrician also does an ASO titer and anti DNAse B assay on her both of which are negative. At this point we would say that she: A. Has asymptomatic infection B. Has opportunistic infection C. Is a carrier D. Is immunosuppressed
blood cells acquires the same organism develops diarrhea followed by hypotension bacteremia sepsis and death.
A person who has a normal healthy immune system acquires a new strain of E. coli that now lives in his gastrointestinal tract. This individual is not ill. A second person with an acute leukemia and no white blood cells acquires the same organism develops diarrhea followed by hypotension bacteremia sepsis and death. This organism is: A. Normal flora for both individuals B. A pathogen for both individuals C. An opportunistic pathogen for both individuals D. One with a low degree of virulence
A 20 year old patient comes to the homeless clinic with a skin abscess on the right arm. A swab from the intact skin overlying this abscess grows coagulase negative staphylococci. An aspirate obtained sterilely with a needle and syringe grows Staphylococcus aureus. About these 2 organisms in this patient you can say: A. Both are normal flora and contaminated the specimens sent to the lab B. The staph aureus is a pathogen and the coagulase negative staph is not C. The coagulase negative staphylococcus is a pathogen D. The coagulase negative staphylococcus is an opportunistic pathogen