CLINICAL MICRO Flashcards
What is a representative member of non-enterococcal group D strep?
S. bovis (subacute endocarditis is perforated colon cancer)
Compare the rash of tick-borne rickettsia to that of louse-borne rickettsia
Tick = RMSF = palms and soles to trunk (centripetal); Louse = epidemic typus (R. prowazekii) = trunk to palms and soles (centrifugal)
What are the Sx of Mycobacterium kanasii?
pulmonary TB like Sx
What disease has morulae in granulocyte cytoplasm)
Anaplasmosis (monocyte would be Ehrlichia)
When growing bugs on EMB agar, what do lactose fermenters look like? What does E. coli look like?
Lactose fermenters = purple, E. coli = purple with metallic green sheen
Why is there no vaccine for N. gonnorrhoaea?
Antigenic variation of the pili
What is the natural reservoir of Borrelia burgdorferi?
mouse
Which type of streptococcal infection (anatomically) is most likely to caus glomerulonephritis?
Skin infections (impetigo) but pharyngitis can still cause it
Name 4 species of Clostridium and their respective toxins
C. difficile (Toxin A = enterotoxin/diarrhea. Toxin B = cytoskeletal damage and pseudomembranous colitis), C. tetani (tetanospasmin), C. botulinum (botulinum toxin), C. perfringens (alpha toxin = phospholipase C)
What bug can you get from cattle and sheep amniotic fluid?
Coxiella burnettii (Q fever); veteranarians
Which form of Hansen’s disease is characterized by a Th2 response?
Lepromatous; recall that Th2 is humoral. Since the severity of leprosy depends on CMI, the presence of a humoral response implies a poor CMI which is why it is lepromatous rather than tuberculoid
What stabilizes the membrane of Mycoplasma pneumoniae?
sterols (no cell wall)
Between which 2 bugs does an optochin test differentiate?
Viridans strep (R ) and S. pneumoniae (S)
What is the Jarisch-Herxheimer reaction?
A flu-like syndrome after initiation of penicillin G for syphilis; due to a release of pyrogens from the lysed bacteria
What causes neonatal staccato cough?
Pneumonia caused by C. trachomatis D-K serotypes
Which type of E. coli ferments sorbitol?
Everything but EHEC
What is the triad of Hemolytic Uremic Syndrome? Most common serotype of E. coli to cause? What other bug can cause?
anemia, thrombocytopenia, and acute renal failure; O157:H7; Shigella spp.
What is the vector for Rickettsia prowazekii?
louse
What is Elek’s test?
The test for diphtheria toxin
How would you treat lumpy jaw?
Ampicillin is the DOC for Actinomyces israelli
What serotypes of C. trachomatis cause lymphogranuloma venereum?
L1, L2 , and L3
What bug can be diagnosed by gram positive rods with metachromatic (blue and red) granules?
Corynebacterium diphtheriae
Name 6 spore formers (Hint: 3 are from the same genus)
B. anthracis, C. perfringens, C. tetani, C. botulinum, B. cereus, Coxiella burnetii (Q fever)
What is the most invasive type of Haemophilus influenzae?
Type B
How do you treat C. trachomatis?
Azithromycin (or doxy) with Ceftriaxone for likely Gonorrheal co-infection
What are the 3 main genera of spirochetes?
Leptospira, Treponema, and Borrelia
Name 3 diseases that have a palm and sole rash
Rickettsia rickettsii (RMSF), Coxsackie A16 (hand foot and mouth), Secondary syphilis
Which species of Strep is hippurate positive?
S. agalactiae
Chronic pneumonia in CF patients is usually caused by _________ and the most important virulence factor here is __________
P. aeruginosa; Biofilm
What is the U.S. reservoir for leprosy?
Armadillo foot pads
Which fastidious gram negative rod will cause hyponatremia?
Legionella pneumophila
What bug has morulae? Vector?
Eherlichia chaffeensis; Lone star tick
What 2 Chlamydial spp. Cause atypical pneumonia?
C. pneumoniae and C. psitiacci
Why is Staphylococcus aureus so good at forming abscesses?
The presence of coagulase (i.e. they are the ONLY coagulase positive G + organism) allows for formation of a fibrin clot and sequestration from the immune system
What is another name for Weil’s disease?
Icterohemorrhagic leptospirosis
What E. coli virulence factors are most important for cystitis and pyelonephritis?
Fimbrae
What bacteria does someone likely have if the X-ray looks worse than the patient?
Mycoplasma pneumoniae
Which type of E. coli flattens villi?
EPEC (P for Peds)
What are the 3 type of anthrax infection?
GI, cutaneous, and pulmonary
What causes diabetic osteomyelitis and sickle cell osteomyelitis?
DM = P. aeruginosa (prob an extension of skin infection of an ulcer) HbS = Salmonella enteriditis
How would you know if an infectious facial palsy was Ramsay-Hunt or Lyme disease?
Ramsay-Hunt syndrome is a VZV bell’s palsy and is unilateral with blistering; Lyme disease is bilateral
Which form of leprosy will have a high Th1 count?
Tuberculoid leprosy; the spectrum of tuberculoid–>lepromatous all depends on CMI
What is the cause of undulant fever?
Brucella
What are 2 possible outcomes of streptococcal pharyngitis that self resolves?
Rheumatic fever and PSGN
What is the gram stain of a bug causing a cherry red epiglottis?
Gram negative coccobacillus
What is the Cioccio general rule for gram positive sensitivities (i.e. novobiocin, bacitracin and optochin)?
Each antibiotic is used to differentiate between 2 bugs, in all cases the bug causing the more severe disease is SENSITIVE to the antibiotic while the less severe bug is resistant to the antibiotic (if you don’t believe me see FA p. 127)
The bacteria grown on Eaton’s agar is common in what 2 demographics?
M. pneumoniae is common in military recruits and prisons
What serotypes of C. trachomatis cause blindness in Africa? What is the pathogenesis here?
A, B, and C? Flies transmit the bug and it causes conjunctivitis with scarring, this occurs over and over again until blind
What do C. trachomatis serotypes L1, L2 and L3 cause?
Lymphogranuloma venereum
What causes aortic aneurysm in tertiary syphilis?
arotitis with destruction of vasa vasorum
What bacteria are carried by these ticks A) Ixodes B) Lone star C) Dermacentor
A) Babesia and B. burgdorferi B) E. chaffeensis C) R. ricketsii (RMSF)
What would you likely see on CXR of a person with Woolsorter’s disease?
Pulmonary hemorrhage and mediastinal widening (B. anthracis)
What is the Tx for Tuberculoid leprosy? Lepromatous?
Tuberculoid = dapsone and rifampin 6 months; Lepromatous = dapsone, rifampin, and clofazimine 2-5 YEARS
A cherry red epiglottis is likely caused by what organism? What sign on CXR?
Haemophilus influenzae B; Thumbprint sign (Steeple sign = Croup, parainfluenzae)
If you ran an electrolyte panel on a patient with Legionairres’ what would you see?
Hyponatremia
How can you differentiate EHEC from other E. coli?
EHEC does not ferment sorbitol
What immune cell infiltrate will you find in the crypts of Salmonella infections vs. Shigella infections?
Salmonella = monocytic; Shigella = PMN
What is the vector for Ehrlichia chaffeensis? What is the typical inclusion body seen?
Lone star tick; morulae
What are your 2 options for treating Mycoplasma pneumoniae?
Macrolide or fluoroquinolone (NO beta lactams bc no cell wall)
What bug causes mediastinal widening?
Pulmonary anthrax
What 2 antibiotics are frequently implicated in pseudomembranous colitis?
ampicillin (beta lactam) and clindamycin (50 S ribosome peptidyltransferase inhibition)
What are the pros and cons to having Anti-M protein antibodies?
Pros: enhances defenses against S. pyogenes, Cons: causes rheumatic fever and PSGN
Everyone knows that alcoholics and DM are the ones who get Klebsiella pneumoniae? BUT WHY?
It is a normal flora of the intestine thus, it gets aspirated? Alcoholics are notorious for aspirating. I’m guessing the DM is because they have autonomic neuropathy and therfore diabetic gastroparesis leading to increased likelihood of aspiration
What is the largest spirochete? What is the thinnest?
Borrelia; Leptospira (lepto = thin)
What is the presentation of primary syphilis? Secondary syphilis?
Primary = painless chancre; Secondary = copper colored maculopapular rash with condyloma lata
Why doesn?t S. aureus require a damaged valve or a pre-existing thrombotic (noninfectious) endocarditis to form bacterial endocarditis while S. epidermidus does?
Because it contains coagulase and can form a fibrin clot around itself which allows it to stick to the valve? S. epi can bind if the valve is damaged and a thrombus has formed on it.
How do you differentiate the Group D strep?
Enterococci grows in 6.5% NaCl and bile; S. bovis only grows in bile
What are the vectors for the 2 spp of Borrelia?
B. burgdorferi = ixodes tick; B. recurrentis = louse
What bug is transmitted by the lone star tick?
Eherlichia chaffeensis
How do you kill spores as in ones that may be leftover on surgical equipment?
Autoclave at 121 C for 15 min
What 2 exotoxins are produced by Clostridium difficile?
Toxin A = enterotoxin causing diarrhea? Toxin B = cytotoxin that damages cytoskeleton of enterocytes = pseudomembranous colitis
How do you treat Listeria monocytogenes?
Ampicillin? But usually only infants, IC pts, and in empirical Tx of meningitis because Listeria gastroenteritis in adults is self-limiting
What do both M. meningitidis and M. gonorrhoeae ferment?
Glucose but meningitidis also metabolizes maltose
In which portion of the bacterial growth curve is an endospore going to form, why?
Stationary phase (top of curve) because this is when growth = death, this is because nutrients are sparse, when nutrients are sparse they initiate survival mode = spore
How do you Tx gonorrhea?
Ceftriaxone (3rd gen) with Azithromycin for likely Chlamydial co-infection
What do serotypes A, B, and C for C. trachomatis cause?
Blindness in Africa
Which type of E. coli produces similar Sx to Shigella but does NOT produce toxin?
EIEC, the invasion causes bloody diarrhea like Shigella
Where does TB usually go when it reactivates and why?
apices of lung because higher ventilation
2 diseases that may present with a saddle nose
Congenital syphilis and Lepromatous leprosy (destruction of septum)
What are the neurological and cardiac manifestations of Lyme disease?
Neuro = bilateral facial palsy (early) and encephalopathy/polyneuropathy (late); Cardiac = AV node block
What bacteria contains a cell wall lacking muramic acid?
Chlamydia
What is the treatment of the 2 filamentous gram positive rods?
Actinomyces = ampicillin; Nocardia = sulfonamides
FTA-ABS is a confirmatory test for what?
Treponema pallidum
What are 4 signs of congenital syphilis?
Mulberry molars, Saber shins, CN VIII deafness, and Saddle nose
Which bacterium inhibits the release of neurotransmitters from Renshaw cells?
C. tetani? Renshaw cells in the spinal cord release inhibitory NTs (GABA and Glycine). Tetanospasmin inhibits their release = spastic paralysis
Aside from the bacitracin test, what are 2 other tests you can use to identify S. agalactiae?
Hippurate test positive and CAMP positive
What is the Tx of Lyme disease (2 drugs), why can’t they go in the sun?
Doxycycline and Ceftriaxone (Doxycycline = a tetracycline, phototoxicity is a notorious AE for this drug)
What is the vector for Rocky Mountain Spotted Fever?
Dermacentor tick
What chemical is added to elicit a positive whiff test for BV?
KOH
What is the screening test for Syphilis? Confirmatory?
VDRL and RPR; FTA-ABS
Which infectious agent leads to a glove and stockings loss of sensation? What disease more commonly does this?
Hansen’s disease (leprosy); Diabetes mellitus
Which antibiotics require O2 for uptake and are ineffective against anaerobes?
Aminoglycosides
What kind of media can Vibrio cholerae grow in? What is the most important aspect of MGMT?
alkaline; REHYDRATION
What causes a thumbprint sign on CXR? Steeple sign?
Thumbprint sign = Haemophilus influenzae B epiglottitis; Steeple Sign = Croup, parainfluenza virus
What shape of gram negative organisms do you use lactose fermentation as an initial measure for differentiation?
Rods? If you have diplococci then you use maltose, if you have coccobacilli then you are dealing with some weird organisms that are fairly fastidious
What is the Tx of Psudeomonas (2 drugs)?
Aminoglycosides and extended spectrum penicillins (Ticarcillin and Piperacillin)
What is carried by the Dermacentor tick?
Rocky mountain spotted fever (Ricketssia ricketsii)
What 2 Bacillus spp. Can cause GI Sx?
B. cereus and don?t forget B. anthracis can also cause GI anthrax!
Which group D strep grow in 6.5% NaCl and and bile?
Enterococci grows in 6.5% NaCl and bile; S. bovis only grows in bile
How do you detect recent strep infection?
ASO titer
E. coli fimbrae are most important for what infections?
Cystitis and pyelonephritis
Triple therapy for H. pylori consists of:
Clarithromycin, metronidazole, PPI
How can you use maltose to differentiate the gram negative diplococci?
N. meningitidis metabolizes maltose whereas gonorrhoeae does not
What causes Traveler’s diarrhea?
ETEC
What do C. trachomatis serotypes D_ _ K cause?
urethritis and PID, ectopic pregnancy, neonatal conjunctivitis/pneumonia (pneumonia = staccato cough)
Why is S. pneumoniae good at infecting mucosal surfaces?
IgA protease
What is the vector for Ricketssia typhi?
Flea (endemic typhus)
Which member of enterococci is an important cause of nosocomial infection?
VRE
Which toxin causes Scarlett fever? What part of the body is spared?
Exotoxin A, Face
Which S. aureus virulence factor inhibits complement fixation and phagocytosis by binding to Fc of IgG?
Protein A
What bug can mimic Crohn’s or appendicitis?
Yersenia enterocolitica
Which TB virulence factor inhibits phagolysosomal fusion?
Sulfatides (surface glycolipids)
Why are Chlamydia obligate intracellular?
Cannot synthesize ATP because have no NAD or CoA (like Ricketssia)
What disease has morulae in monocyte cytoplasm?
Erhilichiosis (granulocytes would be Anaplasmosis)
What are the JONES criteria?
for rheumatic fever: J = joints (migratory polyarthritis) O = pancarditis (ALL layers affected), N = nodules, E = Erythema marginatum, S = Sydenham’s chorea (chorea = caudate or at least the striatum in general)
How do you get Brucellosis?
Unpasteurized milk
Clarithromycin, metronidazole, and omeprazole are a useful therapy in treating a bug that causes what 2 cancers?
Gastric adenocarcinoma and lymphoma (this is triple therapy for H. pylori)
What E. coli virulence factors are the most important for pneumonia and neonatal meningitis
K capsule
What are the reservoirs for Salmonella vs. Shigella?
Salmonella = animals (chickens, turtles); Shigella = humans and primates only
Tetanospasmin inhibits the release of GABA and glycine from these cells ________
Renshaw cells
What does cereulide cause?
this is the virulence factor for B. cereus EMETIC type
What is the cause of reheated rice syndrome?
B. cereus
What are the 3 Sx of tetanus?
Spastic paralysis, Trismus (lock jaw) and Risus sardonicus (you look like the joker)
Differentiate modes of transmission for the Neisseria spp
Gonorrhea = STD; Meningitidis = Oral and Respiratory droplets (infects posterior pharynx)
What 2 classes of drugs are used to Tx Legionella?
Macrolide or quinolone
What serotypes of C. trachomatis cause urethritis and PID?
D-K
What 2 possible “fevers” resulf from Group A strep infections?
Rheumatic and Scarlett
What are the 2 outcomes of Legionella pneumophila?
Legionanaires’ disease (severe) and Pontiac fever (mild and flu-like)
What is the sputum description of S. pneumoniae pneumonia?
Rusty colored sputum
What can you grow Mycoplasma pneumoniae on? What lab test can you order?
Eaton’s agar; Cold agglutinin titer (IgM)
How do you treat C. pneumoniae and C. psitacci? How is it different from C. trachomatis?
Azithromycin; you do not need to give ceftriaxone because you arent concerned about Gonorrhea coinfections with these
Describe the gram stain and shape of S. pneumoniae
Encapsulated, lancet-shaped, gram positive diplococci
In what patient population does Pseudomonas cause External otitis? Malignant external otitis?
External otitis is Swimmer’s ear; Malignant external otitis is in Diabetics
What is the severe form of leptospirosis known as?
Weil’s disease
How does Coxiella present? How do you get it?
Pneumonia; it can form endospores and you inhale them (from the beautiful birth of livestock)
If a person’s pupil constricts on accomodation but does not react to light you are concerned that they got their disease via what route?
Sexual transmission; Argyll-Robertson pupils are typical of neurosyphilis
When do you screen pregnant women for Group B strep? What do you do if they have it? Based off of that, where must it be a normal flora?
35-37 weeks gestation; Give INTRApartum penicillin; normal flora in the vagina of some women
Where is the reservoir for Yersenia enterocolitica?
Animal feces (puppies), but also pork and contaminated milk
Which virulence factor of TB inhibits macrophage maturation and induces release of TNF-alpha?
cord factor
What eponymous sequelae occur with the Neisseria brothers?
N. gonorrhea = Fitz-Hugh-Curtis (infection of the liver capsule, or “Glisson’s capsule” in keeping with the eponym spirit) N. meningitidis = Waterhouse-Freidrichsen (bilateral adrenal hemorrhage with DIC)
What is the vector for Ricketssia ricketsii?
Dermacentor tick
Why is it that H. influenzae can be grown with S. aureus?
S. aureus produces factor V (NAD, nicotinic acid)
What are the Sx of TB?
fever, night sweats, weight loss, and hemoptysis
How is the treatment of all Rickettsial diseases excreted from the body?
Doxycycline is excreted fecally, all other tetracylcines = renally
How do you treat C. diff (2)
Metronidazole is 1st line but you can also give vancomycin
Why are Rickettsiae obligate intracellular?
Need NAD and CoA and can’t make it themselves
In which patient population is S. pneumoniae most likely to cause sepsis and why?
Sickle cell anemics. HbS sickles will autoinfarct the spleen. Since encapsulated organisms are handled via opsonization and splenic clearance, the bacteria that do enter the blood stream are not cleared = sepsis
How can you differentiate S. agalactiae from S. pyogenes?
Group B are resistant to bacitracin and Group A are sensitive (general rule for these gram positives: the good one is always sensitive while the bad one is always resistant)
If a patient’s EKG had more P waves than QRS complexes and you suspected a zoonotic disease, you would likely ask if they were bitten by what?
Tick (Ixodes), Borrelia burgdorferi often causes AV block
What are the 2 sequelae of N. gonorrhoeae?
PID or Fitz-Hugh-Curtis syndrome
What temperatures is Mycobacterium leprae happiest at?
cooler than core temp (like 32-34 I think); this explains why it only infects superficially
What bug causes mesenteric adenitis?
Yersenia enterocolitica
What molecule is at the core of an endospore?
Dipocolinic acid
Which spirochete can only be visualized with aniline dyes? Name the aniline dye
Borrelia (recurrentis, burgdorferi) Wright’s stain aka Giemsa stain
What is lacking from the cell wall of Chlamydia spp.?
muramic acid
What toxin does P. aeruginosa secrete? MOA?
Exotoxin A, an AB toxin that inactivates EF-2 and kills cells
What is the function of Cord factor in TB?
inhibits macrophage maturation and induces release of TNF-alpha (TNF-alpha is responsible for most Sx)
Which drug in the regimen of Hansen’s disease therapy (both tuberculoid and lepromatous) could cause hemolytic anemia in a G6PD deficient patient?
Dapsone
What bug produces pyocyanin?
P. aeruginosa = blue-green pigment
What type of E. coli predominately affects pediatric patients?
EPEC (P for Peds)
Cardiolipin is an antigen used in a screening test for what?
Syphilis (VDRL)
What comes from parrots?
Chlamydia psittaci
What bacteria is from animal urine?
Leptospira spp.
Why don?t you give antibiotics to Salmonella or Shigella?
Prolongs Sx in Salmonella, Prolongs excretion of bug in Shigella (plus releases more Shiga toxin)
Between which 2 bugs does a novobiocin test differentiate?
S. saprophyticus (R ) and S. epidermidis (S)
What are the 4 coccoid rods (i.e. pleomorphic rods) that are gram negative?
Haemophilus influenzae B, Pasteurella multocida, Brucella, and Bordatella pertussis
What virulence factor do both Neisseria and Haemophilus produce?
IgA protease
Which gram negative rod typically has a very mucoid appearance?
Klebsiella pneumoniae (P. aeruginosa also would bc alginate capsule)
What is the treatment of the disease for which clue cells are pathognomonic?
Metronidazole
What does Ricketssia typhi cause?
Endemic typhus
What is the function of surface sulfatides in TB?
inhibit phagolysosomal fusion
What 2 structures does TSST-1 bind to?
MCH II and TCR, this leads to polyclonal (that is, nonspecific) T-cell activation
How do you treat Syphilis?
Penicillin G
What is the reservoir for the GI bug that causes rose spots on the abdomen?
Human gallbladder (Salmonella typhi)
Which beta hemolytic gram positive organism has tumbling motility?
Listeria monocytogenes (gram postive rod)
Name 2 bugs carried by body lice
B. recurrentis and R. prowazekii
How do you treat meningitis caused by H. influenzae? Prophylax?
Ceftriaxone; rifampin
What can you diagnose with a positive urea breath test?
H. pylori (urease forms an alkaline microcosm for H. pylori)
Between which 2 bugs does a bacitracin test differentiate?
S. agalactiae (R ) and S. pyogenes (S)
What will you find on a wet mount of bacterial vaginosis? Tx?
Clue cells (epithelial squamous cells covered in gram-variable pleomorphic rods)
What is the sputum description of K. pneumoniae?
Currant Jelly Sputum
How do the Sx of pulmonary anthrax progress?
MILD FLU LIKE SX that rapidly degenerate to pulmonary hemorrhage, mediastinitis, and septicemia/death
What antibody isotype is present in Cold vs. Warm autoimmune hemolytic anemia? What 2 infectious agents can cause a cold autoimmune hemolytic anemia?
Cold = IgM; Warm = IgG; EBV and Mycoplasma pneumoniae
The lack of which structure yields an avirulent S. pneumoniae?
Capsule
What test is used to identify diphtheria toxin?
Elek’s test
What is the most important virulence factor for S. epidermidis?
ability to form a biofilm (it infects prosthetics and catheters)
What are 2 other names for alpha toxin of C. perfringens?
lecithinase or phospholipase C
What disease (2) comes from the Ixodes tick?
Borrelia burgdorferi and Babesia microti
What is the hemolysis pattern of Viridans streptococci?
alpha; and these unlike the other alpha hemolytic strep (S. pneumo), are optochin resistant
What bacteria is the only one to contain a polypeptide capsule? What amino acid is it composed of?
Bacillus anthracis; poly-D-glutamate
What is the antigen used for the VDRL test? What can cause false positives (5)?
Cardiolipin; Viruses (mono, hep), Drugs, Rheumatic fever, Lupus (anitphospholipid abs), and leprosy
How would you differentiate between 2 oxidase positive gram negative comma shaped bugs?
Campylobacter jejuni grows at 42 and Vibrio cholerae grows in alkaline media
Campylobacter jejuni is a common antecedent to what 2 sequelae?
Guillian Barre and Reactive arthritis
What is the vaccine for diphtheria?
Toxoid vaccine
What encodes diphtheria toxin in C. diphtheriae?
Beta prophage
What’s the deal with gram negatives and penicillin?
Penicillin G and vancomycin cannot penetrate the outer membrane (also the periplasm often contains beta lactamases)? Derivatives can get through, particularly the aminopenicillins: ampicillin and amoxicillin
Name 2 alpha hemolytic gram positive cocci
S. pneumo (optochin S) and Viridans strep (optochin R)
What test enlarges the area of hemolysis that S. aureus creates?
CAMP test–identifies weakly beta hemolytic bugs
How can you differentiate S. saprophyticus from S. epidermidis?
Saprophyticus is resistant to novobiocin and epidermidis is sensitive (general rule for these gram positives: the bad one is always sensitive, the less severe is resistant)
What is the CAMP test? Where does it get its name?
A test that enhances the beta hemolysis formed by S. aureus using another bug, such as S. agalactiae which is also beta hemolytic but only weakly so. It is named after the creators of the test not cAMP
What agar does C. diphtheriae grow on?
Cystine-tellurite
Cord factor is an important virulence factor for ________-
Mycobacterium tuberculosis
Which lactose nonfermenters are oxidase positive (2)?
Pseudomonas and H. pylori
What is ingested by adults vs. kids to cause botulism?
Adults = preformed toxin; Kids = endospores in honey? That’s not to say a kid couldn?t eat the preformed toxin though, just that adults don?t get sick from the endospore in honey
What is the vector for the following: A) R. rickettsii (RMSF) B) R. typhi (endemic typhus) C) R. prowazekii (epidemic typhus)
A) dermacentor tick B) flea C) louse
Which gram negative rod that is a normal flora of the intestines is an important cause of nosocomial UTIs?
Klebsiella pneumoniae
How would you treat active N. meningitidis?
Ceftriaxone or Penicillin G
Surfer from Hawaii presents with jaundice and azotemia? What’s the deal but be specific?
This is Weil’s disease which is hepatic and kidney injury; regular old leptospirosis is jaundice, photophobia, and conjunctivitis but no azotemia
Which bug forms actin rockets? What does it look like on agar?
Listeria monocytogenes (uses actin rockets to go from cell to cell and to move within a cell); tumbling motility
Where does Chlamydia get it’s name?
Chlamys = cloak, it is obligate intracellular
Is the bug that causes hot tub folliculitis aerobic or anaerobic?
P. aeruginosa is an aerobe
Which lactose nonfermenters are oxidase negative (3)?
Shigella, Salmonella, and Proteus
What is the sputum description of S. aureus?
Salmon pink
What is the prophylactic Tx for Mycobacterium avium intracellulare?
Azithromycin (macrolide: bind 23 S of 50 S to prevent translocation of ribosome)
Which bacteria has a polyribosylribitol phosphate capsule?
Haemophilus influenzae B
E. coli K capsule is most important for causing what?
Pneumonia and neonatal meningitis
What are the 2 types of B. cereus infections and their associated foods?
Emetic type = rice and pasta; Diarrheal type = I think just rice??
Name 2 bugs carried by fleas
R. typhi and Y. pestis (PLAGUE)
What is the cause of endemic typhus?
Ricketsia typhi
3 ways to prophylax against N. meningitidis in close contacts
Rifampin (mRNA synthesis), Ceftriaxone (beta lactam), and Ciprofloxacin (DNA gyrase inh)
When a person has P. aeruginosa induced sepsis, what dermatologic finding may be present?
Ecthyma gangrenosum
What is the vector for Recurrent fever? Why is it recurrent?
Louse (variable surface antigen)–Borrelia recurrentis
How can you differentiate Viridans streptococci from S. pneumoniae?
Viridans is resistant to optochin and pneumoniae is sensitive; also S. pneumo has a positive quellung rxn because it is encapsulated (general rule for these gram positives: the bad ones are always sensitive and the less severe is resistant)
90% of duodenal ulcers contain a bug that can be identified with a ________ stain
silver; H. pylori
The H flu B vaccine is a conjugated vaccine. What is conjugated to what?
Polyribosylribitolphosphate polysaccharide capsule of H flue is conjugated to Diphtheria toxin
What is the basis for Lancefield grouping of Streptococci?
Differences in the C carbohydrate of the cell wall
Name 2 oxidase positive rods. Name 2 oxidase positive comma shaped rods.
1) H. pylori and P. aeruginosa 2) Campylobacter jejuni and Vibrio cholerae
What zoonosis comes from unpasteurized milk?
Brucella
What are the 2 drugs for treating Legionella?
Macrolide or Quinolone
What kind of infections does Nocardia cause?
Pulmonary infections and cutaneous infections after trauma in IC pt
What agar is used to grow Legionella pneumophila? How would you REALLY diagnose it?
Buffered Charcoal Yeast Extract (BCYE) with cysteine and iron; urine sample for antigen
Which Viridans strep member causes endocarditis? Dental caries?
Endocarditis = S. sanguis (sanguis = blood), Caries = S. mutans? Both are NF of oral mucosa
The ixodes tick transmits what 2 organisms?
Borrelia burgdorferi and Babesia microti
What is the infectious and replicating form of Chlamydia?
Elementary body infects and Reticulate body replicates
What is the gram stain of Gardnerella vaginalis?
GRAM VARIABLE
What can you get from a cat scratch?
Bartonella henselae
Which filamentous gram positive rod is aerobic?
Nocardia; Actinomyces is anaerobic
The anthrax eschar is composed of A) necrosis and B) and edematous border? What 2 toxins are likely the cause of these 2 aspects of the lesion?
Necrosis = lethal factor (kills MO by cleaving MAPKK, mitogen activated kinase kinases); Edema = edema factor (increased cAMP)
