Review Deck Flashcards
What are the 2 primary causes of pneumonia in adults? Their shapes?
S. pneumoniae = gram positive diplococci
N. meningitidis = gam negative diplococci
What micro shape/main property for TB?
acid fast bacilli
When you see meningitis with petechial rash in college student what should you think?
neisseria meningitidis
What is empiric choice for pneumonia when no organism visible on gram stain?
- ceftriaxone + vancomycin
cef against meningococcus, haemophilus, pneumococcus
vanc incase beta-lactam resistant pneumococcus - sometimes add ampicillin too for listeria [in elderly/pregnant/immunocompromised/etc]
Who gets listeria?
infants, elderly, immunocompromised, pregnant
What is main therapy for N. gonorrhoeae?
cephalosporins [because lots of resistance to fluoroquinolones]
short form: what disease associated with C. difficile?
antibiotic associated diarrhea
short form: what disease associated with C. perfringens
gas gangrene [fatal]
short form: what disease associated with C. tetani
spastic paralysis
short form: what disease associated with C. botulinum
flaccid paralysis
short form: what are micro differences between actinomyces and nocardia?
actinomyces: anaerobic, gram +, yellow sulfur granules
nocardia: aerobic, gram +, modififed acid fast stain
What is SNAP mnemonic?
sulfas –> nocardia
actinomyces –> penicillin
What are main things to treat anaerobes?
- penicillin
- penicillin/beta lactamase inhibitor combo
- 2nd gen cephalosorin
- carbapenem
metronidazole
clindamycin
oral vancomycin
name the organism:
- major cause nosocomial infections
- capsule = imp virulence factor
- alcoholics at greater risk for pneumonia
- mucoid colony
klebsiella pneumoniae
name the organism:
- frequent cause urinary tract infection
- cause many types of GI including turista
- certains strains associated with HUS
E Coli
name the organism:
- associated with day care outbreak blood diarrhea
- low burden of organism to produce disease
- invade M cells in peyers patches
shigella
name the organism:
- massive volume rice water stool
- associated with outbreak in refuge camp
- toxin with 2 subunits that causes massive secretion of fluid and elecrolytes into lumen of small bowel
vibrio cholerae
name the organism:
- diagnoses usually by detection of toxin in stool
- potentially fatal toxic metacolon
- nosocomial diarrhea
- pseudomembranous colitis
C difficile
name the organism:
- pili with adhesive and antiphagocytic functions
- 13 serogroups, vaccine contains A, C, Y W135
- potentially fatal
- treat with penicillin, cephalosporins
neisseria meningitidis
name the organism:
- gram positive rod
- penetrating injuries contaminated by soil
- exotoxin binds inhibitory neurons in spinal cord
- characteristic risus sardonicus
clostridium tetani
name the organism:
- LOS similar to LPS of other gram neg
- chronic infection associated with pelvic inflammatory disease
- opthalmic infection in infants
neisseria gonorrhoeae
name this oganism:
- needs V factors [NAD} and X factor [heme] from S. aureus to grow on blood culture
- incidence of invasive disease greatly declined since use of vaccine
haemophilus influenzae
name this organism:
- small gram neg coccobacillus
- agent of whooping cough
- produces classic AB toxin
- part of TDaP vaccine
bordetella pertussis
What in TDaP vaccine?
- diptheria
- tetanus
- acellular pertussis
name this organism:
- gram + rod
- tumbling end over end
- can spread from GI –> meninges
- bimodal distribution, immunocompromised, pregnant
- treat with ampicillin [not cephalosporins]
listeria monocytogenes
What two bacteria can have ESBL [extended spectrum B lactamases]? What do you treat wtih?
- E Coli and K pneumoniae can have after treatment with broad spectrum antibiotics
- treat with carbapenems
73-year-old woman with a history of diabetes presents with left ear pain and drainage of pus from the ear canal. She has swelling and tenderness over the left mastoid bone. Which of the following microorganisms is the most likely causative agent?
A. Haemophilus influenzae B. Klebsiella pneumoniae C. Mucor sp. D. Pseudomonas aeruginosa E. Streptococcus pyogenes
D. pseudomonas aeruginosa causes malignant otitis externa that can spread to mastoid, meninges, braine
Which of the following organisms would most likely cause infection after a sterilization procedure that killed vegetative cells but did not kill spores?
A. Chlamydia B. Clostridium C. Escherichia D. Pseudomonas E. Streptococcus
B. clostridium
What are the two type of bacterial species that produce spores?
- bacillus [aerobic]
- clostridium [anaerobic]
What is the treatment of choice for stage 1 lyme disease in children? adults?
children = amoxicillin adults = doxycycline
What is the triad of symptoms for rocky mountain spotted fever?
- rash starting at palms/soles and moving in
- fever
- headache
In the pathogenesis of acute diarrhea, which microorganism characteristically penetrates intestinal mucosa of the distal small bowel, multiplies in Peyer’s patches, and then disseminates in the bloodstream?
a. Vibrio cholerae
b. Enterotoxigenic E.Coli
c. Salmonella typhi
d. Rotavirus
e. Clostridium difficile
C. salmonella typhi
When you hear burn victim, green metalic colonies, grape smell what should you think?
pseudomonas
Trying to make crème brulee, a woman burned herself with a blow torch. Two weeks later, her arm became red and streaky with pus and swelling. Green, metallic colonies grew with a grape-like smell on blood agar from a swab of the infection. Her arm itself smells putrid. What are you going to give?
A. Piperacillin/tazobactam B. Cephalosporins C. Macrolides D. Sulfa drugs E. Rifampin
A. piperacillin/tazobactam
What is treatment of choice for pseudomonas?
piperacillin/tazobactam
What STD causes purulent penile discharge and can lead to swollen, inflamed joints? what does it cause in kids?
neisseria gonorrhoeae causes STD and can lead to spetic arthritis. in kids –> infant conjuntivitis
Name the bacteria: mucoid colonies, current jelly sputum
klebsiella pneumonia
Name the bacteria: kid with spinal tap of neutrophils and gram - rods, stiff neck, photophobia, no previous vaccinations
haemophilus influenzae
Name the bacteria: A 10-year-old girl is running across a grassy field when a rusty nail pierces her sweaty running shoe and stabs her in the foot. She received a tetanus booster shot at the doctor’s office and was sent home. 72 hours later, her foot is badly infected and is oozing a greenish-colored discharge.
pseudomonas
Which of the following cannot treat pseudomonas?
A. Cefepime B. Piperacillin & Tazobactam C. Piperacillin & Gentamycin D. Vancomycin E.Imipenem
D. vancomycin
What can vancomycin treat? Not treat?
treats all gram pos including MRSA, enterococcus, staph epidermidis
can’t treat gram negative
A 50-year old diabetic patient comes to the emergency room with a complaint ofright-sided chest pain accompanied by a productive cough. X-ray shows a lobar opacity in the right lung, and gram stain of his bloody, thick, mucoid sputum reveals encapsulated G- bacilli. Susceptibility testing shows the organism does not produce an extended spectrum beta-lactamase, so you go ahead and treat him with:
A. Aztreonam B. Ampicillin C. Tetracycline D. Vancomycin E. Azithromycin
ps. what is the bacteria?
bacteria = klebsiella pneumoniae
treat with aztreonam
All the drugs that can treat pseudomonas [you wont know this just for reference]
- piperacillin [+/- tazobactam]
- 3rd gen cephs: ceftazidime
- imipenem
- aztreonam
- quinolones [cipro, levo]
- aminoglycoside [gentamicin, tobramycin, amikacin]
What disease associated with clostridium botulinum in infants?
infant botulism –> floppy baby syndrome
What disease associated with E. coli in infants?
diarrhea, pneumonia, meningitis
What disease associated with h. influenzae in infants?
epiglottitis, meningitis, pneumonia, otitis media
What disease associated with neisseria gonorrhoeae in infants?
opthalmia neonatorum
What disease associated with listeria in infants?
granulomatis infantiseptica = widespread potentially fatal granulomas
What bacteria associated with waterhouse-friderichsen syndrome?
neisseria meningitidis
What is classic cause of dysentery [multiple, small vol stools with blood, mucus, tenesmus]?
shigella dysenteriae
An immigrant child comes to your clinic with headache, fever, stiff neck, and photophobia. Gram stain shows a gram-negative coccobacillus. The most likely organism:
a. grows on blood agar in the presence of Staph aureus
b. requires a medium containing factor V and factor X
c. grows best on chocolate agar
d. can cause epiglottis and otitis media
e. all of the above
e. all of the above = h. influenza
An immigrant child comes to your clinic because of a sore throat and low grade fever. Examination of the pharynx shows an adherent membrane. Gram stain of the oral secretions show gram-positive rods.
What is the most likely organism?
corynebacterium diptheriae
What is mech of action of diptheriae toxin?
inhibits translation elongation factor II
What bacteria associated wtih fitz-hugh-curtis syndrome?
mostly neisseria gonorrheae [don’t know if also chlamydia?]
= complication of PID causes ectopic pregnancy/infertitily
Does neisseria meningitis have capsule? shape? gram? what can it ferment?
yes it has a capsule
ferments maltose and glucose
gram negative diplococci
What is difference in fermentation between neisseria meningitis and gonorrhoeae?
meningitis = ferments glucose and maltose gonorrhoeae = ferments just glucose not maltose
A two year old girl was sent home from daycare with severe abdominal cramping accompanied by a small volume of bloody stool. Stool samples revealed gram negative rods that were nonmotile, non-lactose fermenting, and did not produce H2S. What is the most likely way this girl contracted this infection?
A. Her pet turtle
B. Contaminated spinach
C. Her unhygienic friend
D. Spoiled milk
shigella –> fecal oral transmission
C. unhygenic friend
A 24year-old male comes to the doctor complaining of dysuria and a purulent discharge from his penis. Gram stain reveals gram negative diplococci. Which of the following is NOT another potential manifestation of this infection in THIS patient?
A. Urethritis B. Septic arthritis C. Epidydimitis D. Pharyngitis E. Fitz-Hugh-Curtis syndrome
E. fitz hugh curtis syndrome
this is n. gonorrhoeae which does cause fitz hugh curtis but exclusively in females
Which 4 bacteria use type III secretion apparatus?
- salmonella
- shigella
- yersinia pestis
- pseudomonas
Which two bacteria secrete toxins that bind translation elongation factor 2 [EF-2]?
- pseudomonas aeruginosa
- corynebacterium diphtheriae
What is mech of action of cholera toxin?
- constititutive activation adenylate cyclase, increases cAMP –> excrete Na/Cl/H2O –> diarrhea
What are the 3 toxins associated with staph aureus and mech?
- toxic shock syndrome toxin 1 [TSST1] works on T cells [toxic shock syndrome]
- exfoliative toxin at intracellular junctions [scalded skin syndrome]
- heat stable enterotoxin [food poisoning]
What is mech of action of shiga toxin?
- inactivates 60s ribosome
What is mech of action of bordatella pertussis toxins?
- pertussis toxin increases activity adenylate cyclase –> cAMP –> mucous production/cough
- tracheal cytotoxin –> interferes with DNA synthesis in respiratory epithelial cells, paralyze respiratory cilia
A 25 year old man comes to see you in July with a rash on the palms and soles of his feet, fever, and headache. He reports taking multiple camping trips in the last few months on the East Coast and noticing multiple tick bites. Which of the following is true of the most likely causative organism?
A. It is normally endemic to the West Coast
B. It is gram positive
C. Its reservoir is in deer
D. It is an obligate intracellular organism
E. It is sexually transmitted
D. it is an obligate intracellular organism
rickettsia rickettssii
Which bacteria is question mark shaped?
leptospira interrogans
What is disease of bartonella henselae? source?
cat scratch fever, from cat/flea
what is disease of ehrlichia chaffeensis? source?
human monocytic ehrlichiosis [HME], lonestar/americanum tick
what is disease of borrelia burgdorferi? source?
ixodes, lyme disease
what is disease of anaplasma phagocytophilum? source?
ixodes, human granulomatic ehrlichiosis [HGE]
what is disease of rickettsia rickettssii? source?
rocky mountain spotted fever, dermacenter tick
A 27 year old woman comes to the physician because of a 3 day history of progressive joint pain in her right knee. She has had three similar episodes within the past several years and claims that she has had multiple sexual partners. Her temp is 38.7C, pulse is 90/min, and blood pressure is 100/70. The ankles and knees are swollen, red, and tender with decreased range of motion. Examination of joint fluid shows a white cell count of 22,000/mm3 and gram staining showed gram negative diplococci. Which of the following is a characteristic of the most likely causal organism that allows it to cause recurrent infections?
A. It is an intracellular pathogen
B.It is resistant to ceftriaxone
C.It is resistant to complement mediated lysis
D. Its pilli undergo antigenic and phase variation
D – it is neisseria gonorrhoeae
A 32 y/o male presents to the ED with progressive difficulty walking over the last two days accompanied by tingling in his feet. PE shows decreased muscular strength in the bilateral lower extremities with absent deep tendon reflexes. His review of systems and PMHx are unremarkable except for a bout of diarrhea two weeks ago that resolved spontaneously. Which of the following agents is most likely associated with this patient’s condition?
A. Vibrio B. Campylobacter C. Salmonella D. Shigella E. Escherichia F. Clostridrium
campylobacter
What bacteria/syndrome: diarrhea that resolved, 2 wks later tingling in feet and progressive difficulty walking
campylobacter –> guillan-barre
An 18 year-old female presents with a tender area of induration in the right buttock which has been present for 2 days. On examination she has a temperature of 38.4C, and a 1 inch in diameter, fluctuant, exquisitely tender, warm and erythematous mass on the right buttock which is surrounded by a 4 inch in diameter area of warm erythema. Which of the following characteristics best describes the cell wall of the organism most likely to be causing this patient’s infection?
A. Contains LPS
B. Contains porin channels
C. Thick peptidoglycan layer
D. Contains a flagellum
C. thick peptidoglycan layer [S. aureus]
A 45-year-old male undergoes a surgical repair of an inguinal hernia. Two days later he complains of pain and discharge from the surgical wound. On exam he has a temperature of 38.3C and erythema, tenderness and purulent discharge from the wound. A gram stain of drainage from the wound shows gram + clusters. Which is the most likely cause of this wound infection?
A. Staphylococcus aureus
B. Staphylococcus epidermidis
C. Streptococcus pyogenes (Group A Strep)
D. Streptococcus agalactiae (Group B Strep)
A. staph aureus
A 6-year-old girl with no underlying medical condition presents to the hospital with 2 days of fever and a rash in her right arm. On exam her temperature is 39.4C and there is a 10cm in diameter area of warm erythema around the left antecubital area which is somewhat tender to palpation. You obtain a blood culture, and after 36 hours you find out that it is growing gram positive cocci in clusters, which on further testing are found to be coagulase negative. Which of the following statements is correct regarding the organism most likely to be present in this blood culture?
A. It uses M-protein to avoid phagocytosis
B. It is part of the normal flora of the gastrointestinal tract
C. It is not causing the patient’s infection
D. It is associated with dental caries
C. It is not causing the patient’s infection
A 7-year-old boy presents with two days of fever, and fatigue and other symptoms of heart failure one month after having had a sore throat for which he did not receive treatment. His past medical history is otherwise negative, including no prior heart disease. On exam he has a HR of 140, temperature of 39.2C, and a diastolic heart murmur best heard at the apex. Blood cultures are negative. What is the most likely mechanism causing this patient’s heart disease?
A. Direct invasion of the heart valves by bacteria
B. Release of an exotoxin by the bacteria
C. Formation of antigen-antibody complexes
D. Molecular mimicry
D. Molecular mimicry [acute rheumatic fever]
A 45-year-old man who has a lymphoma and is currently undergoing chemotherapy is being treated for an episode of bacteremia due to methicillin-resistant Staphylococcus aureus with an intravenous antibiotic. All his chronic medications have been put on hold while he is treated for this infection. Within minutes of receiving a dose of the antibiotic he develops a generalized erythematous rash. On exam his vital signs are BP 120/80, HR 72, T 37.8C. Hives are not present on exam. Which of the following best describes the mechanism of action of the most likely antibiotic this patient is receiving?
A. Disruption of bacterial cell membrane
B. Prevents polymerization of peptidoglycan strands
C. Acts as a detergent on the bacterial cell membrane
D. Inhibits bacterial protein synthesis
B. Prevents polymerization of peptidoglycan strands [vancomycin]
The clinical microbiology laboratory used by your practice uses the Kirby-Bauer method (disc-diffusion) to determine antibiotic susceptibilities. What type of information can you expect to obtain from this test?
A. The MIC of the organism
B. Whether two antibiotics are antagonistic or synergistic
C. A qualitative determination of the susceptibility of the organism
D. Whether a particular antibiotic is bactericidal or bacteriostati
C. A qualitative determination of the susceptibility of the organism
A 24 year old woman presents with burning sensation on urination and urinary frequency. Her exam is normal. She is prescribed cefazolin and a urine culture is sent. After 48 hours her symptoms have improved and the culture has grown E. coli, a gram negative rod, which is resistant to 1st generation cephalosporins. Which is the most likely mechanism of resistance in this case?
A. production of beta-lactamases
B. altered penicillin-binding proteins
C. a mutation in the DNA gyrase
D. ribosomal modification
A. production of beta-lactamases
What is mech of resistance to fluoroquinolones
A. production of beta-lactamases
B. altered penicillin-binding proteins
C. a mutation in the DNA gyrase
D. ribosomal modification
C. a mutation in DNA gyrase
What is the mech of resistance to clindamycin, linezolid, macrolides? A. production of beta-lactamases B. altered penicillin-binding proteins C. a mutation in the DNA gyrase D. ribosomal modification
D. ribosomal modification
A 22-year-old woman presents with an area of warm erythema about 5 cm in diameter around the site of a recent belly-button piercing. She is afebrile and her physical exam is otherwise unremarkable.You would like to treat her as an outpatient with an oral antibiotic. Which of the following agents would be most appropriate?
A. Penicillin
B. Ampicillin
C. Vancomycin
D. Clindamycin
D. Clindamycin
A 22-year-old woman presents with an area of warm erythema about 5 cm in diameter around the site of a recent belly-button piercing. She is afebrile and her physical exam is otherwise unremarkable. What are two most common bacterial causes of this?
- S. aureus, S. pyogenes
You plan to use daptomycin to treat a patient with bacteremia due to Vancomycin Resistant Enterococcus (VRE). Which of the following adverse effects is most commonly associated with this drug?
A. Anaphylaxis
B. Thrombocytopenia
C. Muscle pain and weakness
D. Photosensitivity
C. Muscle pain and weakness
CPK enzyme elevated indicatin muscle inflammation
You plan to use doxycyline. Which of the following adverse effects is most commonly associated with this drug?
A. Anaphylaxis
B. Thrombocytopenia
C. Muscle pain and weakness
D. Photosensitivity
D. photosensitivity
You plan to use linezolid. Which of the following adverse effects is most commonly associated with this drug?
A. Anaphylaxis
B. Thrombocytopenia
C. Muscle pain and weakness
D. Photosensitivity
B. thrombocytopenia
A 65-year-old man presents with 2 days of high fever, cough productive of purulent sputum, and shortness of breath. On exam you notice he is in respiratory distress and has decreased breath sounds on the right lower lobe. A gram stain of his sputum reveals gram positive cocci in pairs and many polymorphonuclear white blood cells. Which of the following antibiotics would be most likely to be effective for this type of infection?
A. ceftriaxone
B. daptomycin
C. azithromycin
D. ciprofloxacin
A. ceftriaxone
this is pneumococcal pneumonia
A 35-year-old man presents to the emergency room complaining of pain on his left lower calf and heel for the past 2 days. He also stated that he has been taking an antibiotic for the past 8 days for the treatment of sinusitis, but he cannot recall the name of the medication. His respiratory symptoms have already resolved, and the patient, who is an avid runner, has restarted training. On exam you notice that his Achilles tendon is very tender to palpation. Which of the following antibiotics was he most likely taking?
A. amoxicillin
B. azithromycin
C. levofloxacin
D. clindamycin
C. levofloxacin
A 74-year-old man presents with a 2 month history of cough which has been getting progressively worse, intermittent fever, and weight loss. He is originally from India, but has been in the US for more than 20 years. On exam you can hear rales over his right upper back. A PPD is read as 22 mm of induration 48 hours after being placed. Which of the following statements is correct regarding the cell wall of the organism most likely to be causing this patient’s symptoms?
A. It has a thick peptidoglycan layer
B. It is rich in Lipopolysaccharide
C. It is rich in Teichoic acid
D. It is rich in Mycolic acid
D. It is rich in Mycolic acid
A 25-year-old man presents with 1 week of cough and body aches. He is not sure if he had a fever, and he does not report shortness of breath. BP is 120/80, HR 82, RR 16, O2Sat 100% on room air. He looks well and his exam is significant only for occasional rales scattered through all lung fields, but with good air entry and no other abnormal findings. His peripheral WBC count is 8,500 cells/mm3 and a chest X-ray shows bilateral infiltrates without focal consolidation. Which of the following is a complication of an organism most commonly associated with the described syndrome?
A. Vertebral osteomylelitis
B. Acute glomeruloneprhitis
C. Erythema Multiforme
D. Acute Bacterial Endocarditis
C. Erythema Multiforme [from mycoplasma pneumoniae]
A 45-year-old woman who has a history of receiving a liver transplant 1 year ago is in the hospital for the treatment of an episode of rejection which includes an increase in the dose of immunosuppressant agents. While in the hospital she develops a new fever, cough and respiratory distress. Her past medical history is significant for autoimmune hepatitis. BP is 110/70, HR 88 RR 22 O2Sat 91% on room air. She has bilateral rales. A urine antigen tests is positive for Legionella. Which of the following strategies would be most useful in identifying the source of infection?
A. Culturing the water supply used for the hospital showers
B. Culturing the nasopharynx of hospital staff who were in contact with the patient
C. Culturing the linens and bed rails in the patient’s room
D. Culturing samples from cutting boards and other utensils in the hospital kitchen
E. Culturing the hands of hospital staff who were in contact with the patient
A. Culturing the water supply used for the hospital showers
no person to person transmission!
A 13-year-old boy with sickle cell disease presents with sudden onset of fever, and while in the emergency room he rapidly becomes lethargic. His BP is 70/30, HR 160, RR 30, T 40.1C. He is somnolent but responds to verbal stimuli. His exam is otherwise normal. The laboratory reports the presence of Howell-Jolly bodies in his red blood cells which you know is indicative of a poorly functioning spleen. Which of the following is most likely to be reported from his blood culture?
A. Gram positive cocci in pairs
B. Gram positive cocci in long chains
C. Gram positive cocci in clusters, coagulase positive
D. Gram positive cocci in clusters, coagulase negative
A. Gram positive cocci in pairs
what bacteria should you think: sickle cell / asplenic patient with pneumonia
strep pneumonia
A 59-year-old man presents with 4 weeks of fevers, night sweats, chills, and weight loss. His past medical history is significant for rheumatic heart disease with stenosis of the mitral valve. BP is 120/80, HR 108, RR 18, T 38.2 C. Several conjunctival hemorrhages are present on physical examination and a diastolic murmur is heard in the left lower sterna border. Which of the following organisms is most likely to be recovered in blood cultures from this patient?
A. Streptococcus mutans B. Streptococcus pyogenes C. Streptococcus agalactiae D. Haemophilus influenzae E. Bordetella pertusis
A. Streptococcus mutans
What are signs of subacute bacterial endocarditis? the cause of subacute bacterial endocarditis?
signs: prolonged fever in pt with underlying heart disease, new heart murmur
cause: step viridans
An 18-year-old woman is brought to the emergency room with 1 day of severe headache. Her roommate, who called 911 when she noticed she appeared somnolent, reports that she was also having fever and vomiting, and complaining that the light bothered her. She is a freshman in college and lives on campus. On exam BP is 80/50, HR 125, RR24 and she is somnolent and confused. She has neck stiffness, photophobia and a petechial rash. A lumbar puncture is performed that reveals hypoglycorrhachia (low glucose), elevated protein, and 1200 white blood cells (90% polymorphonuclear cells). What is the Gram stain of the cerebrospinal fluid most like to reveal?
A. Acid Fast Bacilli B. Gram-positive cocci in clusters C. Gram-positive bacilli D. Gram-negative bacilli E. Gram-negative diplococci
E. Gram-negative diplococci = neisseria meningitidis
A 35-year-old-woman presents to her primary doctor with two days of urinary frequency and dysuria. She is otherwise healthy and reports similar symptoms in the past following sexual intercourse. Her physical exam is normal. Which is the most important virulence factor for the organism most commonly associated with this infection that allows it to cause urinary tract infections?
A. K1 Capsular antigen B. H7 Flagellar antigen C. Production of a Shiga toxin D. Production of a heat labile toxin E. P-pili
E. P-pili = E Coli
What bacteria/disease associated with heat labile toxin?
E coli ETEC = travelers diarrhea
What bacteria/disease associated with K1 capsular antigen?
E Coli strains that cause neonatal meningitis
What bacteria/disease associated with H7 flagellar antigen?
E coli EHEC = HUC
What bacteria/diseases associated with shiga toxin?
- E Coli EHEC –> HUC
- Shigella dysenteriae –> dysentery
An 18-year-old male who is being treated for lymphoma and has been in the hospital for several weeks develops fever. His BP is 80/50, HR 125, RR24, T 39.5. The physical exam is significant for alopecia and the presence of a central venous catheter. A blood culture obtained at the onset of fever is reported 9 hours later as growing a gram negative rod. The following day the laboratory reports that the organism is a lactose fermenting gram negative rod with very mucoid colonies on the MacConkey plate. Which of the following is true regarding the most likely organisms responsible for this patient’s infection?
A. The organism is universally susceptible to betalactams
B. Resistance is mediated by beta-lactamases, but not of an inducible type (ampC)
C. Resistance is mediated by betalactamases, but not of the extended spectrum type (ESBL),
D. Resistance is mediated by betalactamases, including carbapenemases
E. Resistance is mediated by altered penicillin binding proteins.
D. Resistance is mediated by betalactamases, including carbapenemases
lactose fermenting mucoid == think klebsiella
Name this organism: lactose fermenting gram negative rod. mucoid colonies
klebsiella
What are the resistance mech of klebsiella?
universally resistant to ampicillin
inducible ampC betalactamases
two special types of beta lactamases that may present:
ESBL –> resistance to all cephalosporins
KPC –> resistance to carbapenems
A 55-year-old woman presents with one day of fever and back pain. She also reports having 2 days of dysuria and urinary frequency, and noticing foul smelling urine. BP is 110/70, HR 102, RR18, T 38.5C. Her exam is normal except for left costovertebral angle tenderness. Which of the following finding in a urinalysis would support the most likely diagnosis?
A. Clean catch with >100,000 CFU/ml of one single bacterial species
B. Clean catch with >1,000 CFU/ml
C. Clean Catch with >100,000 CFU/ml of 2 different species
D. Catheterized sample with >1,000 CFU/ml
A. Clean catch with >100,000 CFU/ml of one single bacterial species
What is cutoff min number of clean catch colonies for male? female?
female > 50,000-100,000
male >1000
A 75-year-old woman enters the hospital for a hip replacement and receives prophylactic cefazolin prior to the operation and for 24 hours after the procedure. Two days after the surgery she develops abdominal pain and severe bloody diarrhea. Her BP is 110/70, HR 102, RR20, T 38.2C. Her abdomen is distended and diffusely tender to palpation. Labs are significant for an increased peripheral white blood cell count (30,000). Which is the most likely pathogen responsible for her symptoms is?
A. Clostridium tetani B. Clostridium difficile C. Corynebacterium diphtheriae D. Bacteroides fragilis E. Actinomyces israelii
B. Clostridium difficile
A 24-year-old medical student presents to student health with fever to 104 for the past 24 hours. She reports abdominal pain and constipation for the past 3 days, and shaking chills immediately before the fever followed by drenching sweats. She has no significant past medical history but 3 weeks ago she returned from a summer of working in rural Bangladesh on a global health project. While there she had experienced episodes of diarrhea. Her BP is 110/70, HR 90, RR18, T 39.5C. Her physical exam is negative except for diffuse tenderness on abdominal exam. She is admitted to the hospital and several blood cultures are positive for Gram-negative bacilli. On triple sugar iron slants the organism is noted to produce a black pigment indicative of ferrous sulfide. Which is the pathogen most likely responsible for her symptoms?
A. Campylobacter jejunii B. Enteroinvasive E.coli C. Shigella dysenteriae D. V. cholerae E. Salmonella typhi
E. Salmonella typhi
What are characteristics of actinomyces infection
abscesses with sinus tract formation and production of sulfur granules at sites that include the mouth and neck region, lungs, intrabdominal cavity, and brain.
Name the organism: On triple sugar iron slants the organism is noted to produce a black pigment indicative of ferrous sulfide.
Salmonella
A 38-year-old woman is 32 weeks pregnant with twins. She is admitted with fever and headache and fetal heart tracings reveal evidence of fetal distress. She is taken emergently for cesarean section and upon delivery both children are in septic shock and transferred to the neonatal ICU. Both of the twins have blood cultures that are positive for gram positive bacilli. How did the mother acquire this organism?
A. inhalation of respiratory droplets B. inhalation of small droplet nuclei C. contaminated air conditioning systems D. colonization of the genitourinary tract E. ingestion of soft cheese
E. ingestion of soft cheese
What are the 3 most common causes of neonatal sepsis?
- GBS [agalctiae]
- E Coli
- Listeria
Name the organism: Gram pos bacilli, neonatal sepsis
Listeria
A 42-year-old man with Crohn’s disease is being treated for an intrabdominal abscess with an antibiotic regimen that includes metronidazole. What should you tell the patient regarding adverse reactions related to this medication?
A. avoid taking the drug with dairy products
B. avoid taking the drug with food
C. avoid taking alcohol while taking the drug
D. avoid prolonged sun exposure while taking the drug
E. avoid driving or operating heavy machinery while taking the drug
C. avoid taking alcohol while taking the drug
Name the drug: patient should avoid dairy product around time medication is taken
tetracyclines [doxycycline]
Name the drug: commonly have photosensitivity rxn
tetracyclines [doxycycline]
An 8-year-old who has been in the hospital for several weeks receiving chemotherapy for Leukemia through a central catheter develops a fever and signs of septic shock including tachycardia, tachypnea and lethargy. The patient is started empirically on a combination of Cefepime and and gentamicin. Which important adverse effect of the aminoglycoside should this patient be monitored for?
A. Red man syndrome B. QT interval prolongation C. Nephrotoxicity D. Tooth discoloration E. Hepatotoxicity
C. Nephrotoxicity
Match the side effects with the drugs
- isoniazid/pyrazinamide
- aminoglycosides
- macrolides
- Vancomycin
- tetracyclines [do 2 of these]
A. Red man syndrome B. QT interval prolongation C. Nephrotoxicity D. Tooth discoloration E. Hepatotoxicity
- isoniazid/pyrazinamide = E. hepatotoxicity
- aminoglycosides = C. nephrotoxicity
- macrolides = B. QT interval prolongation
- vancomycin = A. red man syndrom
- tetracyclines = B. QT interval + D. tooth discoloration
What are the 2 macrolides?
azithromycin
clarithromycin
What are the two most common side effects of aminoglycosides?
- ototoxicity
- nephrotoxicity
What are the 3 aminoglycosides?
- gentamicin
- tobramycin
- amikacin
A 17-year-old female is brought by her mother to her pediatrician with a chief complaint of being constantly tired for the past 4 months. After going on the internet, the mother is convinced that her daughter has Lyme disease and is demanding a course of IV antibiotics. Which of the following signs or symptoms would most strongly support a diagnosis of Lyme disease?
A. Blisters on the skin B. Erythematous throat C. Hepatomegaly D. Point tenderness over the mid-tibia E. Bradycardia
E. bradycardia = because sign of early disseminated lyme disease is heart block –> bradycardia
What are the signs of early disseminated lyme disease?
- facial nerve palsy
- aseptic meningitis
- heart block –> bradycardia
What are signs of late lyme diseas?
- arthritis of large joints
- peripheral neuropathy
A 72-year-old woman presents with sudden onset of chills, high fever, productive cough, shortness of breath and pleuritic chest pain. BP 110/70, HR 110, RR 24, O2Sat 89% on room air. On exam she is in respiratory distress with supraclavicular and intercostals retractions and has markedly decreased breath sounds on the right. A chest X Ray reveals a consolidation of the right lower lobe, and her peripheral WBC count is very elevated at 35, 000/mm3. Which of the following sputum results best supports a diagnosis of pneumococcal pneumonia?
A. Many WBC, no epithelial cells, many gram positive cocci in pairs
B. Few WBC, no epithelial cells, no organisms seen
C. Many WBC, many epithelial cells, gram positive cocci in chains and in pairs, gram negative diplococcic and short gram negative rods
D. Few WBC, many epithelial cells, gram positive cocci in chains and in pairs, gram negative diplococcic and short gram negative rods
E. Few WBC, many epithelial cells, gram positive cocci in pairs
A. Many WBC, no epithelial cells, many gram positive cocci in pairs
no epithelial cells mean is it a sample from lower respiratory tract
Which of the following statements regarding the gram stain is correct?
A. It has minimal inter-operator variability
B. A negative result can be used to rule out infection
C. When performed on a stool sample, it can be used to determine the etiology of diarrheal disease
D. When performed on a blood sample immediately after collection of the specimen it almost always identifies the pathogen if one is present
E. A positive result can be used to support an etiologic diagnosis
E. A positive result can be used to support an etiologic diagnosis
What is significance of PMNs in stool sample?
invasive infection
What is use of hektoen enteric [H-E] agar?
- identify lactose-fermenting gram negative enteric organisms
- lactose fermenter –> pink
- non-fermenter –> blue/green
- H2S producer –> black precipitate
What color does pseudomonas stain on normal soy agar?
green [from pyocyanin pigment]
How does klebsiella look on MacConkey agar?
pink, mucoid colonies
Which bacteria needs to be plated with staph aureus streak in blood agar?
H. haemophilus –> to get factors V and X
What is responsible for mucoid appearance of klebsiella?
mucoid capsule that has antiphagocytic activity
What is the identification test for strep pneumo?
optochin test = optochin sensitive
What does mycoplasma pnuemoniae look like under stain
can’t be stained –> do serum IgM ELISA or culture or PCR
