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87 Cards in this Set
- Front
- Back
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Which bacteria causes mesenteric adenitis that can mimic Crohn disease or appendicitis? Transmission?
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Yersinia enterocolitica |
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What disease does Yersinia enterocolitica cause? Transmission?
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- Mesenteric adenitis that can mimic Crohn disease or appendicitis
- Transmitted from pet feces (eg, puppies), contaminated milk, or pork |
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Which bacteria causes gastritis and peptic ulcers (especially duodenal)?
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Helicobacter pylori
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Characteristics of Helicobacter pylori?
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G- comma shaped rods
- Oxidase (+) - Catalase (+) - Urease (+) - can use urea breath test or fecal antigen test - Creates alkaline environment |
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What does Helicobacter pylori cause?
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- Causes Gastritis and Peptic Ulcers (especially duodenal)
- Risk factor for gastric adenocarcinoma - Risk factor for lymphoma |
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How do you treat Helicobacter pylori infection?
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Triple therapy:
- Proton Pump Inhibitor (PPI) - Clarithromycin - Amoxicillin or Metronidazole |
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What is the name for spiral-shaped bacteria? Types? Visualization?
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Spirochetes: BLT -
- Borrelia (big size - only spirochete that can be visualized using aniline dyes (Wright or Giemsa stain) with light microscopy) - Leptospira - Treponema (visualized with dark-field microscopy) |
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Which type of bacteria can be visualized with dark-field microscopy?
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Treponema (type of spirochete)
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Which type of bacteria is found in water contaminated with animal urine?
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Leptospira interrogans
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What diseases are caused by Leptospira interrogans infection?
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Leptospirosis
- Flu-like symptoms - Jaundice - Photophobia - Conjunctival suffusion (erythema without exudate) Weil Disease (icterohemorrhagic leptospirosis) - Severe form with jaundice and azotemia from liver and kidney dysfunction - Fever - Hemorrhage - Anemia |
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What is the cause and symptoms of Leptospirosis?
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Leptospira interrogans
- Flu-like symptoms - Jaundice - Photophobia - Conjunctival suffusion (erythema without exudate) |
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What is the cause and symptoms of Weil Disease?
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Caused by Leptospira interrogans
AKA icterohemorrhagic leptospirosis - Severe form of leptospirosis with jaundice and azotemia from liver and kidney dysfunction - Fever - Hemorrhage - Anemia |
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Who is more likely to get infected with Leptospira interrogans (which causes leptospirosis and Weil disease)?
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Prevalent among surfers and in tropics (eg, Hawaii)
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What causes Lyme Disease?
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* Borrelia burgdorferi, which is transmitted by the tick Ixodes (also vector for Babesia)
- Natural reservoir is the mouse (important for tick life cycle) |
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Where is Lyme disease more common?
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NE United States
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What are the initial symptoms of Lyme Disease (Borrela burgdorferi)?
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- Erythema chronicum migrans - expanding bulls eye red rash (picture)
- Flu-like symptoms - +/- Nerve palsy |
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What are the later symptoms of Lyme Disease (Borrela burgdorferi)?
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- Monoarthritis (large joints)
- Migratory polyarthritis - Cardiac - AV nodal block - Neurologic - encephalopathy, facial nerve palsy, polyneuropathy |
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What mnemonic can you use to remember the symptoms of Lyme Disease?
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FAKE a Key LYME pie:
- Facial nerve palsy (typically bilateral) - Arthritis - Kardiac block - Erythema migrans |
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How do you treat Lyme Disease (Borrelia burgdorferi)?
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Doxycycline and Ceftriaxone
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What bacteria causes Syphilis?
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Treponema pallidum (spirochete)
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What are the stages of Syphilis?
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- 1° Syphilis
- 2° Syphilis - 3° Syphilis - Congenital Syphilis |
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What are the signs of 1° Syphilis?
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Localized disease, presents with PAINLESS chancre
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What are the microscopic and lab findings of 1° Syphilis?
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- Dark-field microscopy can visualize treponemes in fluid from chancre
- Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (eg, FTA-ABS) |
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What are the signs of 2° Syphilis?
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- Disseminated disease / Systemic
- Constitutional symptoms - Maculopapular rash (palms and soles) - Condylomata lata (wart like lesions on the genitals) |
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What are the microscopic and lab findings of 2° Syphilis?
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- Dark-field microscopy can visualize treponemes
- Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (eg, FTA-ABS) |
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Following the systemic (2° stage) of syphilis, what happens?
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Latent syphilis stage
- Positive serology without symptoms |
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What are the signs of 3° Syphilis?
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- Gummas (chronic granulomas)
- Aortitis (vasa vasorum destruction) - Neurosyphilis (tabes dorsalis, "general paresis") - Argyll Robertson pupil (constricts w/ accommodation but not reactive to light) - Broad-based ataxia - (+) Romberg's test - Charcot joint (progressive degeneration of a weight bearing joint, marked by bony destruction, bone resorption, and eventual deformity) - Stroke without hypertension |
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What are the lab findings of 3° Syphilis?
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For neurosyphilis: test spinal fluid with VDRL or RPR
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What are the signs of congenital syphilis?
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- Saber shins
- Saddle nose - CN VIII deafness - Hutchinson teeth - Mulberry molars (spreads typically after first trimester) |
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How do you prevent syphilis and congenital syphilis?
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*Treat with Penicillin G
- Prevent congenital syphilis: treat mother early in pregnancy, as placental transmission typically occurs after 1st trimester |
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What is the "Prostitute Pupil"? AKA? Sign of?
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Argyll Robertson Pupil
- Pupil constricts with accommodation but is not reactive to light - Associated with 3° syphilis |
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What is the VDRL test used for? Utility?
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Detects non-specific antibody that reacts with beef cardiolipin; widely used for syphilis (quantitative, sensitive, but not specific)
False positives can be caused by: - Viruses (mono, hepatitis) - Drugs - Rheumatic fever - Lupus and leprosy |
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What is the term for flu-like syndrome that begins after antibiotics are started? Why?
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Jarish-Herxheimer Reaction
- Due to killed bacteria releasing pyrogens (produces fever) |
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What is the Jarish-Herxheimer Reaction?
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- Causes flu-like syndrome that begins after antibiotics are started
- Due to killed bacteria releasing pyrogens (produces fever) |
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What is the term for infectious disease transmitted between animals and humans?
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Zoonosis
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Which zoonotic species is transmitted by Ixodes ticks? Source? Disease?
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Anaplasma species
- Live on deer and mice - Causes anaplasmosis Borrelia burgdorferi - Lives on deer and mice - Causes Lyme disease |
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Which zoonotic species is transmitted by a cat scratch? Disease?
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Bartonella species
- Cat scratch disease, bacillary angiomatosis |
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Which zoonotic species is transmitted by louse? Disease?
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Borrelia recurrentis
- Relapsing fever - Recurrent due to variable surface antigens Rickettsia prowazekii - Epidemic typhus |
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Which zoonotic species is transmitted by unpasteurized dairy? Disease?
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Brucella specia
- Brucellosis / undulant fever |
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Which zoonotic species is transmitted by puppies and livestock? Source? Disease?
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Campylobacter
- Fecal-oral transmission via ingestion of undercooked meat - Bloody diarrhea |
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Which zoonotic species is transmitted by parrots and other birds? Disease?
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Chlamydophila psittaci
- Psittacosis |
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Which zoonotic species is transmitted by aerosols of cattle / sheep amniotic fluid? Disease?
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Coxiella burnetii
- Q fever |
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Which zoonotic species is transmitted by lone star ticks? Disease?
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Ehrlichia chaffeensis
- Ehrlichiosis |
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Which zoonotic species is transmitted by rabbits? Disease?
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Francisella tularensis (also via ticks and deer fly)
- Tularemia |
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Which zoonotic species is transmitted by animal urine? Disease?
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Leptospira species
- Leptospirosis |
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Which zoonotic species is transmitted by armadillos? Disease?
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Mycobacterium leprae
- Leprosy - Also spread by humans with lepromatous leprosy |
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Which zoonotic species is transmitted by animal bites (cats, dogs)? Disease?
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Pasteurella multocida
- Cellulitis and osteomyelitis |
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Which zoonotic species is transmitted by Dermacentor ticks? Disease?
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Rickettsia rickettsii
- Rocky Mountain spotted fever |
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Which zoonotic species is transmitted by fleas? Disease?
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Rickettsia typhi
- Endemic typhus Yersinia pestis - Plaque - Rats and prairie dogs are reservoirs |
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Which zoonotic species has a reservoir in rats and prairie dogs? Disease?
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Yersinia pestis
- Causes the plague - Transmitted by fleas |
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Which bacteria presents as a gray vaginal discharge with a fishy smell?
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Gardnerella vaginalis
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Characteristics of Gardnerella vaginalis?
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- Pleomorphic
- Gram-variable rod - Involved in vaginosis - CLUE cells or vaginal epithelial cells covered with Gardnerella bacteria are visible under the microscope (arrow) |
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What causes Gardnerella vaginalis?
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* Not sexually transmitted
- Associated with sexual activity - Overgrowth of certain anaerobic bacteria in vagina |
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How is Gardnerella vaginalis treated?
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Metronidazole or (to treat anaerobic bacteria) Clindamycin
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What are the vector-born illnesses? Vector?
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- Rocky Mountain Spotted Fever - tick is vector and carries Rickettsia rickettsii
- Typhus - endemic vector is fleas (R. typhi) and epidemic vector is human body louse (R. prowazekii) - Ehrlichiosis - tick is vector and carries Ehrlichia - Anaplasmosis - vector is tick and carries Anaplasma - Q fever - no arthropod vector, Coxiella burnetii spread via tick feces and cattle placenta |
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How do you treat all Rickettsial diseases and vector-borne illnesses?
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Doxycycline
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In which Rickettsial diseases and vector-borne illnesses is a rash common?
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Rash common:
- Rocky Mountain spotted fever (Rickettsia rickettsii - tick) - Typhus (R. typhi - fleas (endemic); R. prowazekii - human body louse (epidemic)) |
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In which Rickettsial diseases and vector-borne illnesses is a rash rare?
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Rash rare:
- Ehrlichiosis (Ehrlichia - tick) - Anaplasmosis (Anaplasma - tick) - Q fever (Coxiella burneii - tick feces and cattle placenta) |
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Which bacteria causes a rash that typically starts at wrists and ankles and then spreads to trunk, palms, and soles? Where is it more common?
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Rickettsia rickettsii (Rocky Mountain Spotted Fever)
- Primarily in S. Atlantic states, especially N. Carolina |
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Characteristics of Rickettsia rickettsii?
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Obligate intracellular organisms
- Requires CoA and NAD+ because they can't synthesize ATP |
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What is the classic presentation of Rocky Mountain Spotted Fever?
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Triad: headache, fever, rash (vasculitis)
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In which infections is there a "palms and soles" rash?
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CARS = you drive CARS using your palms and soles
- Coxsackievirus A infection (hand foot and mouth disease) - Rocky mountain spotted fever - 2° Syphilis (systemic) |
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What are the different causes of Typhus? How do they differ?
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Rickettsia typhi
- Endemic - Spread by fleas Rickettsii prowazekii - Epidemic - Human body louse |
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What are the symptoms of Typhus?
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Rash starts centrally (trunk) and spreads out, SPARING the palms and soles
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What are the characteristics of Ehrlichiosis?
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- Caused by Ehrlichia - vector is tick
- Monocytes with morulae (berry like inclusions) in cytoplasm (picture) - Rarely presents with a rash |
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Which disease is pictured: monocytes with morulae (berry-like inclusions) in cytoplasm?
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Ehrlichiosis - caused by Ehrlichia (vector is a tick)
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What are the characteristics of Anaplasmosis?
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- Caused by Anaplasma, vector is tick
- Granulocytes with morulae in cytoplasm - Rarely presents with rash |
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Which disease is characterized by granulocytes with morulae in cytoplasm?
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Anaplasmosis - caused by Anaplasma (vector is tick)
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What are the characteristics of Q fever?
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- Caused by Coxiella burnetti (can survive outside in its endospore form)
- No arthopod vector - Tick feces and cattle placenta release spores that are inhaled as aerosols - Presents as pneumonia - Rarely presents with rash |
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Which bacteria has Elementary bodies and Reticulate bodies?
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Chlamydiae
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What are the requirements of Chlamydiae?
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Obligate intracellular organisms - cannot make their own ATP
- Cytoplasmic inclusions seen on Giemsa or fluorescent antibody-stained smear - Chlamydial cell wall is unusual in that it lacks muramic acid |
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What kind of infections does Chlamydiae cause?
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Mucosal infections
- C. trachomatis causes reactive arthritis (Reiter syndrome), follicular conjunctivitis (picture), non-gonococcal urethritis, and PID - C. pneumoniae and C. psittaci cause atypical pneumonia (aerosol transmission) |
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What are the two forms of Chlamydiae?
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- Elementary Body (small dense) is "Enfectious" and "Enters" cells via "Endocytosis" where it transforms into a Reticulate Body
- Reticulate Body "Replicates" in cell by fission; "Reorganizes" into Elementary Bodies |
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Which bacteria causes reactive arthritis (Reiter syndrome), follicular conjunctivitis (picture), non-gonococcal urethritis, and PID?
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Chlamydiae trachomatis
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Which bacteria causes atypical pneumonia and is transmitted by an aerosol?
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Chlamydiae pneumoniae and Chlamydiae psittaci (notable for an avian reservoir)
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How do you treat Chlamydiae infections?
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Azithromycin (favored because one time treatment) or Doxycycline
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How do you diagnose Chlamydiae infection?
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Lab: cytoplasmic inclusions seen on Giemsa stain or fluorescent antibody-stained smear
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What are the Chlamydiae trachomatis serotypes?
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- Types A, B, and C
- Types D-K - Types L1, L2, and L3 |
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Which serotypes of Chlamydiae trachomatis cause chronic infection and can cause blindness due to follicular conjunctivitis? Other characteristics?
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Types A, B, and C
- Africa - Blindness - Chronic Infection |
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Which serotypes of Chlamydiae trachomatis cause urethritis / PID, ectopic pregnancy, neonatal pneumonia (staccato cough), and neonatal conjunctivitis?
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Types D-K (everything else)
- Neonatal disease can be acquired during passage through infected birth canal |
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Which serotypes of Chlamydiae trachomatis cause Lymphogranuloma Venereum? Symptoms?
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Types L1, L2, and L3
- Small, painless ulcers on genitals - Swollen, painful inguinal lymph nodes that ulcerate (buboes) - Treat with doxycycline |
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Which bacteria is the classic cause of atypical "walking pneumonia"?
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Mycoplasma pneumoniae (more common in patients < 30 years old; common outbreaks in military recruits and prisons)
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What are the symptoms of "walking pneumonia"? When is this more common? Cause?
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- Insidious onset
- Headache - Non-productive cough - Patchy or diffuse interstitial infiltrate - X-ray looks worse than patient - More common in patients < 30 years old - Frequent outbreaks in military recruits and prisons - Cause: Mycoplasma pneumoniae |
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What are the lab results for a patient with "walking pneumonia" caused by Mycoplasma pneumoniae?
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- X-ray looks worse than patient (patchy or diffuse interstitial infiltrate)
High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs - (remember it is cold in Moscow) - Grows on Eaton agar |
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How do you treat "walking pneumonia" caused by Mycoplasma pneumoniae?
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Macrolide, Doxycycline, or Fluoroquinolone
(penicillin ineffective since Mycoplasma have no cell wall) |
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Why will penicillin be ineffective in a case of walking pneumonia?
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Typical cause is Mycoplasma pneumoniae (which has no cell wall so penicillin will be ineffective)
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Characteristics of Mycoplasma pneumoniae?
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- No cell wall
- Not seen on Gram stain - Bacterial membrane contains sterols for stability |
