A woman with a vaginal discharge has a wet prep done in the E.R. She complains that after intercourse there is a fishy odor. Microscopic examination of a stained wet prep is shown in the figure. The white blood cells in the preparation:
Question 1 - Single Best Answer
The major difference in the etiologies of bacterial meningitis in the community versus nosocomially is:
A) Staphylococcus epidermidis predominates in the hospital, Staphylococcus aureus predominates in the community.
B) Listeria monocytogenes predominates in the community, Streptococci predominate in the hospital.
C) Neisseria meningitidis predominates in the community, Staphylococcus aureus predominates in the hospital.
D) Streptococcus pneumoniae predominates in the community, gram-negative rods predominate in the hospital.
E) None of the above - the etiologies between community and hospital acquired meningitis are the same.
Question 2 - Single Best Answer
Each of the following symptoms suggests pyelonephritis, as opposed to cystitis, EXCEPT:
A) costovertebral angle pain
B) nausea and vomiting
C) fever
D) suprapubic pain
E) None of the above - the symptoms of the two diseases are essentially the same, they are just more severe for pyelonephritis.
Question 3 - Single Best Answer
If you are seeing a patient in the U.S. with community acquired enteric disease, who has not traveled out of the country recently, which set of organisms has a spectrum of disease that would make you consider all three together in a differential diagnosis for this patient?
A) Vibrio cholerae, ETEC, EPEC
B) EHEC, Shigella dysentriae, Clostridium difficile
C) Shigella, Campylobacter, Salmonella enterica serovar Typhimurium
D) Yersinia pestis, Yersinia enterocolitica, Yersinia pseudotuberculosis
E) Salmonella enterica serovar Typhimurium, S. enterica serovar Typhi, Vibrio vulnificus
Question 4 - Single Best Answer
The two bacteria causing the majority of burn infections are:
Answer: Pseudomonas aeruginosa, Staphylococcus aureus
Question 5 - Single Best Answer
Which of the following is NOT a meningeal symptom used for diagnosing bacterial meningitis?
A) headache
B) stiff neck
C) vomiting
D) lethargy
E) All of the above ARE meningeal symptoms.
Question 6 - Single Best Answer
Different types of E.coli are known to cause each of the following EXCEPT:
A) meningitis.
B) urinary tract infection
C) bloody diarrhea
D) watery diarrhea
E) E.coli can cause ALL of the above.
Question 7 - Single Best Answer
In terms of capsule and relationship to macrophages, to which organism is Yersinia pestis most similar?
A) Streptococcus pneumoniae
B) Vibrio vulnificus
C) Bacillus anthracis
D) Haemophilus influenzae type b
E) Rickettsia rickettsii
Question 8 - Single Best Answer
A woman with a vaginal discharge has a wet prep done in the E.R. She complains that after intercourse there is a fishy odor. Microscopic examination of a stained wet prep is shown in the figure. The white blood cells in the preparation:
A) are normal inhabitants of the vagina
B) are normal in the disease that is indicated by the odor and epithelial cell appearance
C) mean that you need to test her for Chlamydia or gonorrhea
D) mean that you need to test for lactobacillus overgrowth
E) None of the above - there are no WBCs in the prep.
Question 9 - Single Best Answer
An 18-year-old woman complained of knee pain that started 2 weeks previously. Three months earlier, soon after vacationing in Connecticut, she noticed a circular area of redness on her lower leg; it was approximately 10 cm in diameter. During the next 2 weeks, the area enlarged and the border became more clearly demarcated; however, the rash gradually disappeared. A few days after the rash disappeared, the woman experienced the onset of headaches, an inability to concentrate, and nausea. These symptoms also gradually abated. The pain in her knee developed approximately 1 month after these symptoms disappeared. On examination of the knee, mild tenderness and pain were elicited. A small amount of serous fluid was aspirated from the joint, and it had an elevated white blood cell count. The diagnosis was made by serology. Which of the following pictures most accurately depicts the most likely causative agent?
A) A
B) B
C) C
D) D
E) E
Question 10 - Single Best Answer
When should ultrasound be used to examine for anatomic defects in urinary tract disease?
A) when the intravenous pyelogram indicates abnormalities
B) any time the urine culture is positive
C) for males only
D) for all upper tract disease
E) None of the above - ultrasound is not used in diagnosing urinary tract infection
Question 11 - Single Best Answer
All of the following are differences between Chlamydia trachomatis and Rickettsia rickettsii EXCEPT:
A) having two cellular forms - a replicative, non-infectious form and a non-replicative, infectious form
B) their animal reservoirs
C) requiring tissue culture for growth in the lab
D) likelihood of fatal versus non-fatal outcome of untreated infection
E) All of the above ARE different between these organisms
Question 12 - Single Best Answer
Surgery should be used in managing otitis media with effusion:
A) always
B) only when antibiotics fail after one week
C) after 3 months
D) only with cranial nerve symptoms
E) never
Question 13 - Single Best Answer
Deep wound infections with accumulations of gas and necrosis in tissues is most often caused by:
A) a spore-forming, obligate anaerobe that secretes exotoxins
B) a gram-positive coccus
C) an obligate anaerobe, gram-negative rod
D) a halophilic, comma-shaped gram-negative bacterium
E) a pleiomorphic gram positive, filamentous rod
Question 14 - Single Best Answer
A 22-year-old female schoolteacher was brought to the emergency room after a 2-day history of headache and fever. On the day of admission, the patient had failed to come to school and could not be reached by telephone. When notified of this fact, the patient's mother went to her daughter's apartment, where she found her daughter in bed, confused and highly agitated. The patient was rushed to the local hospital, where she was comatose on arrival. Purpuric skin lesions were present on her trunk and arms. Analysis of her CSF revealed the presence of 380 cells/mm3 (93% polymorphonuclear leukocytes), a protein concentration of 220 mg/dl (elevated), and a glucose concentration of 32 mg/dl (decreased). There had been three other similar cases in the school over the preceding two weeks.
A gram stain of the CSF of the patients would most likely reveal:
A) gram-negative coccobacilli
B) gram-positive diplococci
C) gram-negative diplococci
D) gram-negative rods
E) gram-positive rods
Question 15 - Single Best Answer
The most important component of treatment for perihepatitis is:
A) antivirals to inhibit Hepatitis Virus B infection
B) anti-inflammatories such as steroids because this is an autoimmune reaction to viral infection
C) antibiotics to kill infecting bacteria
D) All of the above
E) None of the above - this syndrome is self-limiting.
Question 16 - Single Best Answer
Which virulence factors are most associated with upper tract urinary tract infection versus lower tract infection?
A) hemolysin and adhesins that recognize receptors other than mannose
B) production of endotoxin and adhesins that recognize mannose receptors
C) resistance to trimethoprim and sulfa drugs
D) motility and resistance to complement
E) polysaccharide capsule and glycocalyx
Question 17 - Single Best Answer
Of the non-O1 Vibrio cholerae strains, which group causes the most human disease?
Answer: O139
Dr. Gulig wrote this on the board for you during his lecture and told you to write it down. It is important in the epidemiology of cholera
Question 18 - Single Best Answer
A decrease in the number of endocarditis cases since 1930 can be attributed to:
A) the fact that Staphylococcus aureus has remained sensitive to penicillin.
B) the fact that there are fewer untreated cases of Strep throat.
C) better antibiotics to kill the bacteria that reside in the mouth.
D) the use of more artificial heart valves.
E) None of the above, the number of endocarditis cases has not decreased since 1930.
Question 19 - Single Best Answer
A 61-year-old woman with left-sided face pain came to the emergency department of a local hospital. She was unable to open her mouth because of facial muscle spasms and had been unable to eat for 4 days because of severe pain in her jaw. Her attending physician had noted trismus (difficulty in moving the mandable) and risus sardonicus (grin caused by facial spasm). The patient reported that 1 week before presentation, she had incurred a puncture wound to her toe while walking in her garden. She had cleaned the wound and removed small pieces of wood from it, but she had not sought medical attention. She had not received vaccinations since she was 15 years old. This patient should be treated with:
A) Antibiotics alone
B) Antibiotics plus toxoid vaccination
C) Antibiotics plus anti-toxin
D) Toxoid vaccination plus anti-toxin
E) Antibiotics plus muscle relaxers
Question 20 - Single Best Answer
How is the Venturi effect related to infectious disease?
A) Only motile organisms can cause upper tract urinary tract disease
B) One should not perform a lumbar puncture when there is evidence of papiledema.
C) The petechial rash of Rocky Mountain Spotted Fever spreads from the extremeties to the trunk.
D) It determines which loci are most prone to endocarditis.
E) None of the above.
Question 21 - Single Best Answer
A 25-year-old, previously healthy woman came to the emergency room for the evaluation of bloody diarrhea and diffuse abdominal pain of 24 hours duration. She complained of nausea and had vomited twice. She reported no history of inflammatory bowel disease, previous diarrhea, or contact with other people with diarrhea. The symptoms began 24 hours after she had eaten an undercooked hamburger at a local fast food restaurant. Rectal examination revealed watery stool with gross blood. Sigmoidoscopy showed diffuse mucosal erythema and petechiae with a modest exudation but no ulceration or pseudomembranes. Treating this infection with a quinolone antibiotic would not be appropriate because:
A) Shigella is resistant to the quinolones due to their overuse.
B) The normal flora will be disrupted and further intestinal damage could ensue.
C) The SOS response of the causative agent will stimulate production of a virulence factor encoded on a lysogenic phage.
D) Quinolones select for transmission of the virulence plasmid encoding the most important virulence determinant of this disease process.
E) Intestinal infections are never treated with antibiotics since the infections are either resistant to antibiotic treatment or the diseases are self-limiting.
Question 22 - Single Best Answer
Clostridium botulinum is known to cause each of the following disease processes EXCEPT:
A) Infection of macrophages after inhalation of spores, germination, then sepsis leading to death.
B) Ingestion of preformed toxin in improperly canned food leading to paralysis.
C) Contamination of a wound by spores, germination, and toxin production.
D) Ingestion of spores, germination in the intestines, production of a toxin leading to paralysis.
E) None of the above - C. botulinum DOES cause each of the above disease processes.
Question 23 - Single Best Answer
What form of specific/adaptive immunity would be central to preventing most enteric infections?
Answer: Answer sIgA
You had to say IgA to get full credit. If you added other stuff, it counted against you if it was wrong.
Question 24 - Single Best Answer
Which two bacterial species grow at 4C?
Answer: Listeria monocytogenes and Yersinia enterocolitica
Had to specify enterocolitica
Question 25 - Single Best Answer
What do the three leading bacterial agents causing acute otitis media and sinusitis have in common?
A) They are all gram-positive.
B) They are all obligate anaerobes.
C) They all produce beta-lactamase, hence must be treated with alternative antibiotics.
D) They are all normal flora.
E) All of the above
Question 26 - Single Best Answer
Which of the following pairs of toxins are not A-B toxins?
A) E. coli Stable Toxin (ST) and Staphylococcus aureus enterotoxin
B) Cholera toxin and E. coli Labile Toxin (LT)
C) Tetanus toxin and Botulinum Toxin
D) Lethal Toxin and Edema Toxin of Bacillus anthrax
E) None of the above - all bacterial toxins are A-B toxins by definition.
Question 27 - Single Best Answer
A VDRL test for syphilis:
A) may be positive in a person with lupus in the absence of syphilis.
B) may be negative in a woman that is pregnant with syphilis.
C) utilizes treponemal flagellar antigen to look for antibodies to the organism.
D) is a definitive test for syphilis.
E) cannot be used to test for tertiary syphilis.
Question 28 - Single Best Answer
A Negri body is found where in the body and is associated with what disease?
Answer: brain rabies
Question 29 - Single Best Answer
List three changes in Yersinia pestis as it evolved from Yersinia pseudotuberculosis.
Answer: gain plasmids, infect fleas, shut off genes, chromosomal rearrangements, not infect human gut
Question 30 - Single Best Answer
Chlamydia trachomatis is known to cause each of the following EXCEPT:
A) trachoma, a disease of the eyes that causes blindness
B) inclusion conjunctivitis in newborns
C) urethritis
D) cystitis
E) lymphogranuloma venereum
Question 31 - Single Best Answer
All of the following are symptoms of acute sinusitis EXCEPT:
A) fever
B) tooth pain
C) facial pain
D) drainage from the nose
E) sinus effusion
Question 32 - Single Best Answer
The most common causes of neonatal meningitis are:
A) Streptococcus pneumoniae and Neisseria meningitides
B) E. coli K1 and Streptococcus agalactiae (Group B Strep)
C) HSV1 and Treponema pallidum
D) Neisseria gonorrheoea and Chlamydia
E) Haemophilus influenzae type b and Listeria monocytogenes
Question 33 - Single Best Answer
Name three toxins that have ADP-ribosylating activity
Answer: cholera, diphtheria, bordetellaŠalso LT that is just like cholera
Question 34 - Single Best Answer
Two weeks following a corneal transplant Mr. X presented to the E. R. with severe mental status changes and a low-grade fever. A lumbar puncture indicated a mild lymphocytic pleocytosis (25 white blood cells/mm3) and a mildly elevated protein. His mental status rapidly deteriorated and he died three weeks following his transplant. Based on similar events at other hospitals you believe he died of:
A) Pneumococcal meningitis
B) Neisseria meningitidis meningitis
C) a brain abscess
D) HSV1 encephalitis
E) rabies
Question 35 - Single Best Answer
The bacteria found in most cases of subacute bacterial endocarditis would have what type of hemolysis on blood agar?
A) alpha
B) beta
C) gamma
D) they wouldn't grow on blood agar, they are fastidious
Question 36 - Single Best Answer
HSV2 is dangerous in pregnant women because:
A) it can be transmitted to the fetus in utero.
B) it can infect the baby during the time of delivery.
C) it can cause encephalitis in the mother.
D) it is more contagious to her partners during pregnancy
E) it can cause sterility
Question 37 - Single Best Answer
In community acquired meningitis the most common route of transmission of bacterial pathogens to the meninges is:
A) direct inoculation via trauma.
B) direct spread from otitis media, sinusitis, or mastoiditis.
C) via the blood.
D) a ruptured brain abscess.
E) via a cribiform plate defect.
Question 38 - Single Best Answer
Which of the following do viral meningitis and viral encephalitis have in common?
A) headache as a symptom
B) coma and death as likely consequences
C) spectrum of causative agents
D) insect/arthropod vectors
E) All of the above - these are essentially the same disease, just different in severity.
Question 39 - Single Best Answer
Which of the following groups is LEAST susceptible to urinary tract infection?
A) sexually active females
B) men older than 70 years of age
C) paraplegics
D) patients with bladder catheters in place for weeks
E) otherwise healthy normal children
Question 40 - Single Best Answer
To help identify Trichomonas vaginalis, it is important to:
A) place a drop of potassium hydroxide on the microscope slide first.
B) place a drop of potassium hydroxide on the cervical os.
C) place copious saline on the microscope slide.
D) not use a cotton or Dacron swab.
E) heat fix the slide before microscopic examination.
Question 41 - Single Best Answer
Bacteriuria:
A) is always treated with antibiotics
B) is always associated with symptoms
C) only occurs with upper urinary tract disease
D) only occurs with lower urinary tract disease
E) None of the above.
Question 42 - Single Best Answer
A 65 year old alcoholic male with primary hemochromatosis consumes oysters on the half shell (raw). He experiences flu-like symptoms of fever and malaise over the next 48 hours. Large bullous (fluid-filled, bloody) lesions appear on his legs, and his fever increases while his blood pressure drops. Which of the following is most consistent with this disease?
A) Most other people who consumed the same oysters were not significantly at risk for acquiring this disease.
B) The oysters were contaminated by human sewage.
C) Preformed toxins were produced in the oysters before they were consumed.
D) The oysters were contaminated with spores that germinated in the man's intestines.
E) The man has impetigo, which is unrelated to the consumption of oysters because the organisms are only found in humans.
Question 43 - Single Best Answer
In women, the most commonly applied cutoff for differentiating contamination of a "clean catch" mid-stream voided urine sample by normal flora as opposed to indicating urinary tract infection is:
A) any measurable bacteria in the urine.
B) 10^3 bacteria/ml.
C) 10^5 bacteria/ml.
D) 10^7 bacteria/ml.
E) only determined by culturing urine to identify the bacteria present.
Question 44 - Single Best Answer
A patient in the surgical unit at Shands is placed on antibiotics after surgery to repair a compound fracture. Two days later the patient experiences bloody diarrhea, and sigmoidoscopy reveals pseudomembrane formation of the colon. Which of the following accurately describes the most likely disease process?
A) Normal skin flora infected the surgical wound and secreted a superantigen-type toxin that caused damage to the intestinal epithelium.
B) Obligate anaerobic, gram-negative normal flora of the intestines invaded through lesions of the intestines caused by the antibiotics and caused peritonitis.
C) A spore-forming normal flora produced toxins that killed epithelial cells.
D) The patient consumed improperly cooked beef in the hospital and became infected with an acid-resistant, toxin-secreting, E. coli strain.
E) The antibiotic enabled outgrowth of normal flora that invaded epithelial cells, escaped the endocytic vacuole, and then killed the host cell.
Question 45 - Single Best Answer
The disease with symptoms most like Toxic Shock Syndrome is:
A) Scalded Skin Syndrome.
B) food poisoning.
C) necrotizing fasciitis.
D) endotoxemia.
E) cat scratch disease.
Question 46 - Single Best Answer
For endocarditis to occur one must have Nonbacterial Thrombotic Endocarditis AND:
A) endotoxemia
B) bacteremia
C) immunosuppression
D) dental procedure
E) colonoscopy
Question 47 - Single Best Answer
A 22-year-old man in Orlando who had not traveled out of the country came to the emergency department with a history of burning on urination and purulent discharge that developed after he had sexual contact with a prostitute. Gram stain of the discharge revealed abundant gram-negative diplococci resembling Neisseria gonorrhoeae. The patient was treated with penicillin and sent home. Two days later, the patient returned to the emergency room with a complaint of persistent, watery urethral discharge. Abundant white blood cells but no organisms were observed on Gram stain of the discharge. Culture of the discharge was negative for N. gonorrhoeae. The diagnosis of the most likely cause of this man's disease will be made by:
A) blood agar culture.
B) serology.
C) PCR.
D) dark field microscopy of exudate.
E) None of the above are useful in diagnosing this man's disease.
Question 48 - Single Best Answer
Staphylococcus aureus is known to cause each of the following disease processes EXCEPT:
A) preformed toxin in food
B) local infection with systemically active toxin
C) sepsis
D) skin infection
E) S. aureus CAN cause all of these diseases.
Question 49 - Single Best Answer
Name 2 bacteria that cause biofilm-type infections on implanted medical devices.
Answer: Pseudomonas aeruginosa and Staphylococcus epidermidis
Question 50 - Single Best Answer
A 27-year-old man in Oklahoma was mowing his field when he ran over two young rabbits. When he stopped his mower, he realized that two other rabbits were dead in the unmowed part of the lawn. He removed all the rabbits and buried them. Three days later he developed a fever, muscle aches, and a dry, nonproductive cough. Over the next 12 hours he got progressively sicker and was transported by his wife to the area hospital. Results of a chest X-ray showed infiltrates in both lung fields. Blood cultures and respiratory secretions were collected, and antibiotics were initiated. Blood cultures became positive after 3 days of incubation, and the same organism grew from the respiratory specimen that was inoculated onto a special agar. Each of the following describes the most likely cause of this man's illness EXCEPT:
A) Close contacts of the man were not at risk of acquiring the infection from him.
B) Transmission of the disease to the man did not directly involve an arthropod.
C) The man could have been vaccinated to prevent this disease.
D) The organism possesses a capsule even though it lives within phagocytes.
E) Inhalation is the only common method of acquiring this infection from animals.
Question 51 - Single Best Answer
Hemolytic Uremic Syndrome is caused by:
A) ascending infection up the urinary tract.
B) locally produced but systemically active toxin
C) bacteria seeding the kidneys via the blood after intestinal infection
D) autoimmune cell-mediated immunity similar to Rheumatic fever
E) immune complex deposition similar to post-streptococcal glomerulonephritis
Question 52 - Single Best Answer
What do the vaccines against the major causes of community acquired bacterial meningitis have in common?
A) The killed cells stimulate cell-mediated immunity to the intracellular pathogens.
B) The capsular polysaccharides stimulate circulating IgG to opsonize the extracellular pathogens.
C) The nasal administration of live, attenuated bacteria stimulates the mucosal immune system to produce sIgA to prevent colonization.
D) Injection of toxoids prevents systemic damage caused by locally produced toxins.
E) None of the above - there are no effective vaccines against the major causes of bacterial meningitis.
Question 53 - Single Best Answer
Syphilis is more frequently transmitted transplacentally during primary and secondary syphilis of the mother BECAUSE:
A) the damage caused to the placenta is healed late in the infection.
B) the organisms are attracted to the uterus by the erythritol.
C) the fetus is more susceptible early in the pregnancy, as in rubella infections.
D) there are more organisms in the bloodstream early in the infection
E) the damage to the placenta is done by the IgM.
Question 54 - Single Best Answer
A 26 year old medical student travels to Bangladesh to help vaccinate children against polio. She experiences profuse, watery diarrhea leading to a five pound weight loss. There were no RBCs or WBCs in her stool. However, gram-negative curved rods were predominantly observed on a stool gram stain. Which of the following most accurately describes the most likely disease process?
A) If the student has a course of illness similar that experienced by most of the local population and does not receive antibiotics, she most likely will die.
B) The bacteria have attached to the intestinal epithelium with an "attaching-effacing" lesion stimulating fluid secretion.
C) A toxin is produced that is causing necrosis of the intestinal epithelium by stopping protein synthesis.
D) A toxin was secreted that acted like a hormone by binding to a receptor on the enterocytes without entering the cell.
E) A toxin was produced that stimulated cAMP in enterocytes.
Question 55 - Single Best Answer
A 24-year-old man living in North Carolina came to the local emergency department because of fever, arthralgias, myalgias, and malaise. He was well until 4 days before admission, when he developed a fever reaching 40C, chills, severe headache, and muscle aches. Physical examination revealed a critically ill man with a temperature of 39.7C, pulse of 110 beats/min, respiratory rate of 28 breaths/min, blood pressure of 100/60 mm Hg, and a rash over his extremities including his palms and soles. The patient recalled having had numerous tick bites 10 days before the onset of symptoms. The diagnosis was confirmed by serology. Which of the following describes the most likely causative agent for this man's disease?
A) It has two cellular forms - a replicative and an intracellular form.
B) It lives within the cytoplasm of infected cells.
C) It is a spirochete.
D) It has a capsule, even though it lives within phagocytes.
E) The infective stage is a spore.
Question 56 - Single Best Answer
Which two bacterial pathogens are highly resistant to stomach acid, hence have low infectious doses (less than 1000 cells)?
Answer: Shigella EHEC EIEC
Question 57 - Single Best Answer
A sexually active female presents with pharyngitis. All of the following should be considered in the differential diagnosis EXCEPT:
A) Streptococcus pyogenes
B) Neisseria gonorrhoeae
C) Adenovirus
D) Chlamydia trachomatis
E) All of the above should be part of the differential diagnosis for this case of pharyngitis.
Question 58 - Single Best Answer
A mother and her 4-year-old son came to the local emergency room with a 1-day history of diarrhea and abdominal cramping. Both patients had low-grade fevers, and pus was grossly evident in the child's stool specimen. The symptoms had developed 18 hours after the patients had consumed a dinner consisting of mixed green salad, chicken, corn, bread, and apple pie. Culture of blood samples was negative for organisms, but the causative agent was identified from stool specimens of both the mother and the child when plated on special agar incubated at 42C. Gram stain of the cultured organism revealed curved gram-negative rods. What non-intestinal sequella are these patients now at risk for?
A) Toxic shock like syndrome
B) Hemolytic Uremic Syndrome
C) Guillan-Barre Sydrome
D) Glomerulonephritis
E) Necrotizing fasciitis
Question 59 - Single Best Answer
The major symptoms/signs that differentiate acute otitis externa (OE) from necrotizing OE are:
A) pain and drainage in the external ear canal for acute OE only.
B) signs of cranial nerve damage and granuloma tissue in necrotizing OE only.
C) visible fungal growth in necrotizing OE only.
D) pus behind the tympanic membrane for necrotizing OE only.
E) None of the above - the symptoms are the same, just more severe for necrotizing OE.
Question 60 - Single Best Answer
On this map of the United States, in which two regions would you LEAST expect to encounter either Lyme disease or Rocky Mountain Spotted Fever (meaning neither is likely to be present)?
A) Red and Blue
B) Green and Red
C) Blue and White
D) Green and White
E) None of the above - these diseases are spread equally throughout the country.
Question 61 - Single Best Answer
A new antibiotic has been discovered that targets porins. It must be given for a week and does not enter eukaryotic cells. This would be most useful in the treatment of:
A) listeriosis
B) Rocky mountain spotted fever
C) cholera
D) tetanus
E) brucellosis
Question 62 - Single Best Answer
Name three diseases caused by three different spirochetes
Answer: leptospirosis, Lyme disease, syphilis
Question 63 - Single Best Answer
Type Three Secretion System secreted toxins are known to perform each of the following EXCEPT:
A) induce uptake of bacteria into host cells
B) prevent phagosome-lysosome fusion
C) prevent phagocytosis of bacteria
D) stimulate the attaching-effacing lesion
E) All of the above ARE known activities of Type Three Secreted Toxins
Question 64 - Single Best Answer
Treatment of bacterial endocarditis requires bactericidal agents because:
A) the organisms are present in low numbers, so significant reduction of their numbers is difficult.
B) the agents lack cell walls.
C) the bacteria are sequestered from phagocytes.
D) the bacteria in the lesion are present as spores.
E) only immunocompromised patients get bacterial endocarditis.
Question 65 - Single Best Answer
A 45 year old male contracts typhoid fever that was traced back to some chicken salad. The most likely scenario for this case is:
A) organisms from the chicken's intestine were not killed because the chicken was not properly cooked.
B) the food was prepared by an infected person.
C) the patient is immunocompromised.
D) the chicken was contaminated with soil.
E) Any of the above could equally contribute to this case.
Question 66 - Single Best Answer
Which etiologic agent of otitis media is most significant in terms of the severity of symptoms and risk for complications?
A) Moraxella catarrhalis
B) Haemophilus influenzae type b
C) Non-typeable Haemophilus influenzae
D) Streptococcus pneumoniae
E) Neisseria meningitidis
Question 67 - Single Best Answer
In which of the following sites would you NOT expect to find Salmonella enterica serovar Typhimurium?
A) mycotic aneurysm
B) blood
C) liver
D) bone
E) None of the above - Salmonella enterica serivar Typhimurium can be found in all of these sites.
Question 68 - Single Best Answer
What is the leading cause of both community acquired and nosocomial urinary tract infection and where is its anatomic reservoir?
Answer: E. coli intestinal tract
Question 69 - Single Best Answer
Bacterial vaginosis is a direct risk factor for:
A) cancer
B) pelvic inflammatory disease
C) cystitis
D) ectopic pregnancy
E) None of the above
Question 70 - Single Best Answer
Name 3 causes of genital ulcer disease.
Answer: Haemophilus ducreyi (chancroid), HSV, Treponema pallidum, LGV
Question 71 - Single Best Answer
A 48 year old white male presented to the hospital with the sudden onset of severe occipital headache. CT scan revealed subarachnoid hemorrhage due to an aneurysm of his left middle cerebral artery. The following day he underwent neurosurgery, and the aneurysm was clipped. A ventriculostomy (tube placed in the lateral ventricle to prevent build up of CSF pressure) was placed and allowed to drain to a sterile container. On the third postoperative day he developed a fever to 101 F. His peripheral WBC was 8,500. CSF fluid was obtained (see below). He was started on cefazolin after cultures of the CSF and blood were obtained. His fever resolved and he felt better until postoperative day 10 when he noted the sudden onset of a severe generalized headache, photophobia and stiff neck.
PE: Temp 100 F BP 178/86 P 92 RR 18
Moaning, restless and lethargic
HEENT: shaved head, surgical scars healing well. Fundi: normal disc margins
Neck: Positive Brudzinki's sign
Lungs: Clear
Heart: No Murmur
Abdomen: non tender
GU: foley catheter in place
Extemities: no edema
Skin: no rashes
Neurological exam: lethargic but could be aroused, answered questions appropriately, no focal neurological deficits noted.
LAB Post op Day 10: WBC 18.5 73% PMN 8% bands
CSF:
Day 3 Postop: TP 55, Glucose 76 (serum 100), RBC 2000, WBC 20 (42 PMN, 58 monos)
Day 10 Postop: TP 160 Glucose 48 (serum 110), RBC 40, WBC 2600 (92 PMN, 3 monos)
1. What factors could have predisposed this gentleman to postoperative infection? (include at least 2 factors) (1 point)
2. Do you agree with the initiation of cefazolin in this case? Why/Why not? (1 point)
3. How would you interpret the CSF formula on Postop Day 3? (1 point)
4. How would you interpret the CSF formula on Postop Day 10? (1 point)
5. What organisms should be covered while you are waiting for your culture results? (Include at least 2) (1 point)
Answer: 1. What factors could have predisposed this gentleman to postoperative infection? (include at least 2 factors) (1 point) Neurosurgery could result in inoculation of bacteria into the CSF Placement of a ventriculostomy He also had a bladder catheter that could have led to bacteremia His surgical wound could allow bacteria to gain entry into the central nervous system
2. Do you agree with the initiation of cefazolin in this case? (1 point) Cefazolin is a first generation cephalosporin and would not be expected to cross the blood brain barrier. It is obvious that this drug was ineffective because the patient developed meningitis while on it. Therefore, the correct answer could be inferred and did not require memorization (ie. Did not require reciting but rather require that you sight read the music).
3. How would you interpret the CSF formula on Postop Day 3? (1 point) This is consistent with a resolving subarachnoid hemorrhage. Blood in the CSF would be expected to have a few WBCs (approximately one WBC per 100-300 RBCs). The glucose and protein are normal consistent with this likely possibility. Furthermore the differential of the WBC is predominant mononuclear cells not PMNs.
4. How would you interpret the CSF formula on Postop Day 10? (1 point) This is a classic bacterial meningitis CSF formula: Increased WBC with >90% PMN, low CSF glucose and high protein
5. What organisms should be covered while you are waiting for your culture results? (Include at least 2) (1 point) You need to cover the organisms associated with nosocomial meningitis:
Question 72 - Single Best Answer
Mr M was a 70 yo WM who presented with C.C. Fever and left shoulder pain.
2 months prior to admission he underwent aortic valve replacement because of severe aortic stenosis. He was feeling well until 2 days before admission, when he noted a fever to 101.6F, malaise and decreased appetite. The day of admission he came to the ER because of the onset of severe left shoulder pain and stiffness. He also noted increasing shortness of breath when lying flat and when he tried to walk more that 20 feet.
PE Temp 100.7F, BP 157/90 P96 R 24
HENT Conjunctiva normal, fundi: sharp disc margins no hemorrhages or exudates
Lungs: bibasilar rales 1/3 up both lung fields
Heart: normal S1, loud S2, II/VI SEM right upper sternal border radiating to the carotid arteries, II/VI holosystolic murmur at left lower sternal border
Abd: normal bowel sounds, no hepato-splenomegally
Ext: no edema, multiple splinter hemorrhage noted in the distal nailbeds of both hands, remainder of skin and extremities without lesions. Decreased range of motion of his left shoulder as well as marked tenderness to palpation.
Neuro: Alert, no focal deficits
LAB WBC 8,000 (77% PMN L 10% M 12%) Hct 35, ESR 49 (nl 10-20)
CXR: diffuse opacification consistent with pulmonary edema
1. How would you diagnose this patient's illness? Discuss the criteria you would use. (2 points)
2. What organism or organisms are most likely to explain his illness and why? (1 point)
3. How do you explain his shoulder pain? (1 points)
4. Who would you call to help manage this patient, and what would you expect them to do? (1 point)
Answer: 1. How would you diagnose this patient's illness? Discuss the criterion you would use. (2 points) You should draw 3 blood cultures at least 15 minutes apart to document constant bacteremia. You should order a trans-esophageal echo to look for a prevalvular leak, prosthetic valve dysfunction and myocardial abscess. Duke's criterion are used to help confirm the diagnosis of bacterial endocarditis in the absence of surgery. The major criteria are:
2. What organism or organisms are most likely to explain his illness and why? (1 point) This is acute bacterial endocarditis. Also the infection occurred in the period for early prosthetic valve endocarditis (First 2 months after surgery) The most likely organism would be S. aureus; although enterococcus is also possible. Gram negative bacilli are also possible. Coagulase negative Staph is less likely given the acuteness of his illness, but if you include this it will also count. .
3. How do you explain his shoulder pain? (1 point ) He seeded his shoulder joint with bacteria causing early septic arthritis. Left shoulder pain could also be referred pain from the spleen and be due to a septic splenic infarct.
4. Who would you call to help manage this patient, and what would you expect them to do? (1 point ) Given the fact that the patient is already in CHF, this is an indication for surgery. You would want to consult cardiology to help improve his CHF prior to surgery and you would want to consult the cardiac surgeon to replace his infected prosthetic valve. You might want to also consult a rheumatologist to aspirate his left shoulder joint for cell counts and culture.