Micro Flashcards
Encapsulated bacteria
“SHiNE SKiS”
Strep pneumo, Hib, Neisseria meningiditis, E coli, Salmonella, Klebsiella, and gBs
+ Pseudomonas!
What yeast has a capsule?
What are 2 stains for the organism?
Cryptococcus neoformans (meningitis in AIDS pts) India ink and mucicarmine
What is transformation?
What is transduction?
Transformation - when a live bacterium takes up free DNA released from nearby lysed cells and incorporates it into their genome
Transduction - when a bacteriophage brings along bacterial DNA with it’s viral genome. Once it infects another bacteria, it will gain the donor bacterial DNA
What bacteria can undergo transformation?
“SHiN”
Strep pneumo, Hib, and Neisseria meningiditis
What is transposition?
When a small part of DNA is self-exiled from it’s chromosome and moves to a new location (i.e. a plasmid)
Genetic material isn’t actually exchanged between bacteria, BUT this would allow an ax-resistance gene to move to a plasmid where it would be shared via conjugation
What 3 species can form spores?
Bacillus, clostridium, and Coxiella burnetii (Q fever)
Giemsa stain
“Certain Bugs Really TRY my Patience”
Chlamydia, Borielal, Rickettsiae, TRYpanosomes (african sleeping sickness), and Plasmodium
What molecule does PAS stain?
What organism is detected with a PAS stain?
Stains glycogen.
Detects Tropheryma whipplei (Whipple disease)
India ink
Cryptococcus neoformans (AIDS meningitis)
Silver stain (3)
Legionella, H pylori, and fungi (PCP)
Ziehl-Neelsen stain
Acid fast = Mycobacterium and norcadia
Food poisoning (vomiting) associated with potato salad
Staph aureus
Food poisoning (vomiting) associated with reheated rice
Bacillus cereus
What does Protein A do?
What bacterium expresses it?
Binds Fc region of host IgG (expressed on PM)
Staph aureus
Bacteria associated with the pigment:
Gold
Yellow
Green
Gold - Staph aureus “Au = gold”
Yellow - Actinomyces isrelii
Green - Pseudomonas
Pneumonia with rust colored sputum - what is the organism?
Strep pneumo
What type of infection can Staph saprophytic cause?
UTI - especially in young, sexually active women
What bacteria have IgA protease?
What other 2 characteristics do these bacteria all have in common?
“SHiN” - Strep pneumo, Hib, and Neisseria meningiditis
They are also all encapsulated and are capable of transformation
Sandpaper-like rash + strawberry tongue
Scarlet fever - toxin mediated (pyro- and erythro-genic toxins)
What bacteria causes necrotizing fasciitis?
Strep species (especially strep pyogenes)
What are the 3 most common causes of neonatal meningitis?
GBS, E coli, and Listeria
What are 3 causes of strawberry tongue?
Scarlet fever, kawasaki disease, and vitamin B12 deficiency
What 3 bacteria are associated with subacute endocarditis?
Viridans strep, enterococcus, and Strep bovis
Cystine-tellurite agar
Corynebacterium
What two toxins can be made by Clostridium perfringens and what diseases do they cause?
Gas gangrene - a toxin (a phospholipase)
Food poisoning - enterotoxin (reheated meat)
What 2 abs could b e used to treat diphtheria?
Penicillin or erythromycin
What infection is associated with people that work with goat hair?
Bacillus anthrasis
What are 3 obligate anaerobes?
What two antibiotics can be used?
Clostridium tetani, Actinomyces, and Bacteroides
Clindamycin or metronidazole
Gram+ rod that grows at cold temperature (room temp) + narrow zone of B hemolysis
Listeria
What is the treatment for Actinomyces isrelii?
Penicillin
Headache + fever + rash
What is the treatment?
Rickettsial infection (RMSF, typhus, ehrlichiosis, anaplasma, and Q fever) All are treated with Doxycycline
What 4 infections can cause a rash on the palms and soles?
“drive Kawasaki CARS with your hands and feet”
Kawasaki disease, Coxsackie A, RMSF, and secondary Syphillis
Headache + fever + rash that spares palms/soles
What vector transmitted the bacteria:
Rickettsia typhi
Rickettsia prowazekii
Rickettsia typhi - fleas (“thyphi = thyFLEA”)
Rickettsia prowazekii - lice (“prowasekII = lIIce”)
Nonspecific flu-like illness (with fever) + inclusions in monocytes or granulocytes
What is the treatment?
Monocytes - Ehrlichiosis
Granulocytes - Anaplasma
Tx - Doxycycline (a rash-rare rickettsial subtype)
Risk factor includes birthing farm animals
Q fever (Coxiella burnetii)
What 3 organisms can be spread through unpasteurized milk?
Listeria, Coxiella burnetii (Q fever - pneumonia), and Brucella (recurrent fever)
What are 2 presentations of Coxiella burnetii (Q fever)?
Acute pneumonia (fever lasting several weeks) or chronic endocarditis
What are 3 presentations of Chlamydia?
Follicular conjunctuvitis ("ABC = africa, blindness, chronic infection") Urethritis/PID Lymphogranuloma venerium (painless genital ulcers + unilateral ulcerative LAD)
What is the treatment for suspected sexually transmitted Chlamydia?
Azithromycin (chlamydia) + Ceftriaxone (gonorrhea)
What bacteria are associated with reactive arthritis?
Chlamydia and diarrhea bugs (shigella, salmonella, campylobacter, and yersinia)
Pet parrot + pneumonia
Treatment?
Chlamydia psittaci
Tx - azithromycin (all Chlamydia bugs)
What 3 bacteria can cause atypical pneumonia (nonproductive cough + flu-like, Xray looks worse than the pts feels)?
Legionella pneumophila, Chlamydia pneumoniae, and Mycoplasma pneumoniae
What is the treatment for atypical pneumonia?
Macrolide (azithromycin)
What non-pneumonia phenomonon is associated with Mycoplasma infection?
IgM cold agglutinins (also with CLL and EBV)
What organisms of transmitted by animal urine?
Leptospira interrogans and Hantavirus
What is Weil disease?
Severe Leptospira infection = liver and kidney dysfunction
What 2 symptoms characterize each stage of Lyme disease?
Stage 1 - early localized
Stage 2 - early disseminated
Stage 3 - late disseminated
Stage 1 - flu-like + erythemia migrans
Stage 2 - fluctuating AV block + bilateral Bells palsy
Stage 3 - migratory arthritis + encephalopathy
What is the treatment for Lyme disease?
Doxycycline
What symptoms characterize secondary (2 sxs) and tertiary (3 sxs) syphillis?
Secondary - rash on palms/soles + condyloma lata
Tertiary - gummas + aortitis + neurosyphillis (general paresis dementia, tabes dorsalis, and argyll-robertson pupil)
What is used to screen for syphillis?
VDRL (sometimes also called RPR) - tests for serum reactivity against a cardiolipin (non-specific, happens to be in all pts with syphillis)
What can cause a false + on VDRL?
“Suspicious Positive VDRL”
SLE, Pregnancy, Visuses (EBV), iv Drug users, Rheumatic fever, and Leprosy
What organism causes Bacillary angiomatosis (confused with Kaposi sarcoma)?
Bartonella (also Cat Scratch Disease)
2 bacterial causes of recurrent fever
Borriella recurrentis and Brucella
Transmitted via rabbits
Francisella tularensis “rabbits eat tulips”
Transmitted via armadillos
Leprosy
Cellulitis/osteomyelitis from a cat/dog bite
Pasteurella multocida
Transmitted via prairie dogs
Boubonic plague (painful inflamed lymph nodes) - Yersinia pestis
What RNA viruses are naked?
“my REal HEavy PICture of CALIfornia was Ruined without an envelope”
REovirus (rota), HEpevirus (HEV), PICornavirus (PERCH), CALIcivirus (noro) = Rna
What DNA viruses are naked?
“PA PA and Aunt POLY Didn’t have an envelope”
PApilloma (HPV), PArvovirus (B10), Adeno, POLYoma (JC) = Dna
What is reassortment?
Which viruses can participate?
Co-infection allows viruses to exchange segments of DNA
Reovirus (rota), influenza, and hantavirus
What is recombination?
Co-infection allows non-homologous recombination of chromosomes in areas with similar sequences - progeny is a completely new virus
Only occurs in DNA viruses and retro viruses (RNA virus with DNA phase)
What is the only ssDNA virus?
Parvovirus (“parvo = small”)
Child with diarrhea in winter months
Rotavirus
Aseptic meningitis in summer months
Echovirus
What are the 3 most common presentations of Coxsackie virus infection?
Hand/foot/mouth disease (papules/ulcers), myocarditis, and pericarditis
How would Coltivirus present?
“COLorodo TIck fever = COL TI virus”
Self-limited flu-like in a hiker (outdoorsy person)
What virus is most active in the winter? In the summer?
Winter = rotavirus (diarrhea in kids) Summer = echovirus (aseptic meningitis)
What 2 viruses cause the common cold?
Rhinovirus and coronavirus
What 2 viruses cause aseptic meningitis?
Echovirus and coxsackievirus
High fever + hemorrhage + jaundice
Yellow fever
Severe musculoskeletal pain + retro-orbital headache + fever
Dengue fever
Complication = hemorrhagic fever
How does West Nile virus spread?
How does it present?
Birds to mosquitos to humans
Flu-like. Some progress to meningitis/encephalitis
What family do each of the hepatitis viruses (except HDV) belong?
HAV - picornavirus (+ ssRNA, PERCH)
HBV - hepadnavirus (partial dsDNA circular)
HCV - flavivirus (+ ssRNA)
HEV - hepevirus (+ ssRNA)
What drug is used as prophylaxis for vertical transmission of HIV?
Zidovudine (NRTI)
What are the side effects for the following protease inhibitors:
Ritonavir
Indinavir
Atazanavir
Ritonavir - P450 inhibitor, pancreatitis
Indinavir - nephrolithiasis
Atazanavir - nephrolithiasis, increased bilirubin (“AtAzanavir
What are 2 side effects of protease inhibitors as a class?
GI upset and lipdystrophy/hyperTG
What are the side effects for the following NRTIs:
Abacavir
Didanosine
Zidovudine
Abacavir - life-threatening hypersensitivity reaction
Didanosine - pancreatitis, peripheral neuropathy, hepatic steatosis (“Dan Died = we should wear PPH”)
Zidovudine - bone marrow suppression (EX megaloblastic anemia) (“Zidovudine Zaps the marrow”
What are the side effects of NRTIs as a class?
Lactic acidosis
What are 2 side effect of NNRTIs as a class?
Rash and hepatotoxicity
What are 3 side effects specific to Efevirenz?
Neuro-psych changes (dizziness, depression), marajuiana false positive test, teratogen
What is the mechanism of:
Raltegravir
Enfuvertide
Miraviroc
Raltegravir - integrase inhibitor
Enfuvertide - gp41 fusion inhibitor (cannot enter cell)
Miraviroc - binds CCR5 to prevent gp120 binding
What is the treatment for cryptococcus meningitis?
Amphoteracin B + flucytosine (converted to 5FU by fungal enzymes) followed by fluconazole
Recent travel to Latin America + severe pneumonia + granulomas in mucus membranes
Paracoccidioides = dimorphic fungi with captains wheel appearance on imaging
“PARAcocco PARAsails with the captains wheal all the way to latin america”
Where do systemic mycoses generally disseminate to?
What additional place does coccidioidomycoses disseminate to?
Skin and bone
Cocco - also to CNS (meningitis)
What 2 fungi are transmitted via bird/bat droppings?
Histomycoses (dimorphic, endemic fungus) and cryptococcus neoformans (meningitis in AIDS pts)
Treatment for sporothrix schenckii
Itraconazole or potassium iodide
“Transmitted by planting roses in your POT = treat with POTassium iodide”
What is the most common side effect of amphoteracin B?
Azoles?
Nephrotoxicity
Hepatotoxicity (increases LFTs)
What is used for prophylaxis in AIDS pts for:
Candida (CD4
Candida - Itraconazole
Cryptococcus - Fluconazole
What is the treatment for endemic mycoses (Histo, blast, cocoa, paracocco)?
Itraconazole
What is the mechanism of terbinafine?
What is it used to treat?
Inhibits squalene epoxidase Dermatophyte infecitons (Tineas)
In addition to the flask-shaped ulcer and bloody diarrhea, what other finding is seen with Entamoeba histolytica infection?
Liver abscess
What do entamoeba histolytica cysts look like on light microscopy?
Round with multiple nuclei
What is the treatment for toxoplasma?
Sulfadiazine + pyramethamine (DHFR inhibitor)
What parasite is transmitted through freshwater lakes?
Naegleria fowleri (rapidly fatal meningo-encephalitis) "Naegleria sounds like Nalgene"
What causes Chagas disease?
Trypanosoma cruzi
What parasite is transmitted by the sandfly?
Leishmania donovani
Spiking fevers + hepatosplenomegaly + pancytopenia + macrophages containing small amastigoes
Visceral leishmaniasis
Slow healing ulcerative papules
Cutaneous leishmaniasis
How can you differentiate the gametocyte of Plasmodium falciparum from other subtypes?
It’s banana shaped
What is the treatment for malaria?
What do you add if it’s vivid or oval?
What do you use if it’s falciparum (likely resistant)?
Chloroquine
+ primaquine
Atovaquone/proguanil or mefloquine
Metrozoite cross in RBC
Babesia
What 3 organisms are transmitted via the Ixodes tick?
Borellia burdorferi (lyme disease), anaplasma (chlamydiophila bacteria), and babesia (protozoan hemolytic anemia)
What is the presentation of the following roundworms:
- Enterobius vermicularis
- Ascaris lumbricoides
- Strongyloides stercoralis
- Ancylostoma/Necator
- Anal pruritis
- Loffler eosinophilic pneumonitis (gut-lung-gut)
- Peptic ulcer-like pain, vomiting (skin-lung-gut)
- Anemia (skin-lung-gut)
Treatment for roundworms (except strongyloides)
Bendazoles or pyrantel pamoate
Myositis + periorbital edema + eosinophilia
Trichinella spiralis (from undercooked game meat)
What roundworms are transmitted by ingestion?
Which roundworms are transmitted by skin penetration?
“EAT” - Enterobius (anal pruritis), Ascaris (loffler eosinophilic pneumonitis), and Trichinella (game meat)
“SANd” - Strongyloides (peptic ulcer-like), Ancyclostoma and Necator (anemia)
What is the treatment for strongyloides?
Ivermectin
What is the consequence of ingesting Taenia solium larvae?
Ingesting Taenia sodium eggs?
Larvae = tapeworm Eggs = cysticercosis (muscle) or neurocysticercosis (brain)
What does praziquantel treat?
Tapeworms (taenia solim, diphyllobothrium) and flukes (schistosoma, clonorchis)
Treatment for neurocysticercosis
Albendazole
Biopsy procedure of liver mass results in anaphylaxis - what is the mass?
Echinococcus granulosus cysts (transmitted via dogs)
Eosinophilia + megaloblastic anemia
Diphyllobothrium latum (fish tapeworm)
Eosinophila + portal HTN
Schistosoma mansoni (invades the mesenteric vasculature and can cause vascular obstruction)
Egyptian immigrant with bladder squamous cell CA
Schistosoma haematobium
Eosinophila + pigmented gallstones
Clonorchis sinensis - increases risk for cholangioCA
What is the presentation of Wuchereria bancrofti?
Elaphantitis (transmitted via mosquito)
What parasite can be treated with Amphoteracin B?
Leishmania donovani - visceral leishmaniasis
Prophylaxis against N meningiditis
Treatment for N meningiditis
Prophylaxis - Rifampin (also for Hib)
Treatment - Ceftriaxone
What is the first step in treatment for H influenza epiglottis?
Secure the airway (if you do anything else first they may cry and lose their airway)
Chocolate agar + factors 5 and 10
Hib
“when you’re sick with the FLU, mom runs to the 5 and DIME store to get some CHOCOLATE”
Severe atypical pneumonia + GI symptoms + CNS changes
Legionnaires disease (legionella pneumophila)
What lab abnormality is associated with Legionnaires disease?
HypoNa
How is legionella transmitted?
Contaminated water (air conditioner, sprinkler system, history of cruise or hotel)
What is the triple and quadruple therapy for H pylori?
Triple = PPI + metronidazole/amoxacillin + clarithromycin (macrolide) Quadruple = PPI + Bismuth + metronidazole + tetracycline
IF you chose to treat Gram - diarrhea, what 3 antibiotics could be used?
Fluoroquinolone, TMP-SMX, or azithromycin
Fever + salmon colored spots on the abdomen
Salmonella typhi
Diarrhea + pet turtle
Salmonella
What bacteria are associated with reactive arthritis?
Salmonella, shigella, campylobacter
Pseudoappendicitis
Yersinia enterocolitica
“Currant jelly sputum”
Klebsiella pneumonia
Who is at high risk for Klebsiella pneumonia?
Alcoholics and diabetics
“Swarming motility” + urease positive
Proteus (UTI with strive stones)
Lowenstein-jensen agar
TB
What antibiotic is used to treat latent TB?
Isoniazid
What is the mechanism of the TB drugs?
Rifampin - RNApol inhibitor
Isoniazid - block mycolic acid synthesis
Pyrazinamide - acidify phagolysosomes
Ethambutol - block other cell wall carb synthesis
Side effects for TB drugs
R (2), I (3), P (2), E (1)
Rifampin - hepatotoxicity, Ramps up P450s and Red/orange body fluids
Isoniazid - hepatotoxicity, peripheral neuropathy (vitB6 deficiency), and drug-induced lupus
Pyrazinamide - hepatotoxicity and gout
Ethambutol - red/green color blindness (ONLY one that’s non-hepatotoxic)
What is the presentation of Mycobacterium kansasii?
TB-like illness