Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
331 Cards in this Set
- Front
- Back
What is positive sense RNA?
|
Viral RNA that can be used as mRNA
|
|
What is negative sense RNA?
|
Viral RNA that is complientary to mRNA and needs virion associated RNA-dependant RNA polymerase
|
|
What are the arboviruses?
|
Togavirus, flavivirus, bunyavirus
|
|
Viruses inactivated by heat, detergents and solvents
|
Enveloped viruses
|
|
Viruses that can't be inactivated by heat, detergents and solvents
|
Naked viruses
|
|
How do dsDNA viruses make mRNA?
|
Negative strand of genome serves a template for mRNA. No intermediate.
|
|
How do retroviruses make mRNA?
|
mRNA is transcribed from dsDNA intermediate.
|
|
How do +RNA viruses make mRNA?
|
Through a -RNA intermediate
|
|
How do -RNA viruses make mRNA?
|
RNA is template for +mRNA without intermediate
|
|
What are the killed vaccines?
|
Rabies, Influenza, Polio (Salk), A hepatitis. "RIP Always"
|
|
What are the live vaccines?
|
Mumps, Rubella, Varicella-Zoster, Measles, Adenovirus, Polio (Sabin), Small Pox, Yellow Fever. "Mr. V.Z. Mapsy"
|
|
What are the DNA virus families?
|
Herpes, Hepadna, Adeno, Parvo, Pox, Papova. "HHAPPPy"
|
|
What are the naked virus families?
|
Calicivirus, PEeCoRnA virus, Reovirus, Parvo, Adeno, Papilloma, Polyoma. "Naked CPR and PAPP smear"
|
|
What are the +RNA virus families?
|
Calici, PEeCoRnA, Flavi, Toga, Corona, Retro. "Call Pico and Flava To Come Rap"
|
|
What are the -RNA virus families?
|
PaRaMyxo, Rhabdo, Arena, Filo, Orthomyxo, Bunya, Delta. "Para Rabiar in the Arena, Fill or Buny"
|
|
Characteristics of DNA viruses
|
All dsDNA (except parvo); All linear (except papova, hepadna); Icosahedral (except pox); Replicate in the nucleus (except pox); All naked (except herpes, hepadna, pox)
|
|
Characteristics of Herpesviruses
|
Enveloped, dsDNA, linear, icosahedral, replicates in nucleus, intranuclear inclusion bodies and latency
|
|
Characteristics of hepadnaviruses
|
Enveloped, dsDNA, circular, icosahedral, replicates in nucleus
|
|
Characteristics of adenovirus
|
Naked, dsDNA, linear, icosahedral, replicates in nucleus
|
|
Characteristics of Parvovirus
|
Naked, ssDNA, linear, icosahedral, replicates in nucleus
|
|
Characteristics of Papovavirus
|
Naked, dsDNA, circular, icosahedral, replicates in nucleus
|
|
Characteristics of Poxvirus
|
Enveloped, dsDNA, linear, complex, replicates in cytoplasm (DNA-dependant RNA polymerase)
|
|
Characteristics of Caliciviruses
|
Non-enveloped, +ssRNA, linear, icosahedral
|
|
Characteristics of PEeCoRnA viruses
|
Non-enveloped, +ssRNA, linear, icosahedral
|
|
What are the Herpes viruses?
|
HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-8
|
|
What are the PEeCoRnA viruses?
|
Polio, Echo, Coxsackie, Rhino, Hep A. "PEeCoRnAvirus"
|
|
What are the Caliciviruses?
|
HEV, Norwalk
|
|
What are the Reoviruses?
|
Reovirus, Rotavirus
|
|
What are the Flaviviruses?
|
HCV, yellow fever, dengue, St. Louis encephalitis, West Nile virus
|
|
What are the Togaviruses?
|
Rubella, eastern equine encephalitis, western equine encephalitis
|
|
What are the Retroviruses?
|
HIV, HTLV
|
|
What are the Orthomyxoviruses?
|
Influenza
|
|
What are the Paramyxoviruses?
|
Parainfluenza, RSV, Rubeola (Measles), Mumps. "PaRaMyxovirus"
|
|
What are the Rhabdoviruses?
|
Rabies
|
|
What are the Filoviruses?
|
Ebola
|
|
Pathogenesis of Parvovirus B19
|
Infects immature erythroid progenitors resulting in lysis. May cause aplastic crisis in sickle-cell anemia.
|
|
Pathogenesis of HSV
|
Infects epithelial cells with formation of vesicles. Establishes latent infection in the ganglion. Reactivation with stress.
|
|
Pathogenesis of VZV
|
Respiratory tract --> local lymph node --> primary viremia --> spleen and liver --> secondary viremia --> skin rash --> latency in dorsal root ganglia --> reactivation due to stress causes vesicular lesions and severe nerve pain
|
|
Pathogenesis of EBV
|
Infects nasopharynx, salivary and lymphoid tissue --> latent infection in B cells via CD21 receptor --> production of atypical T lymphocytes with heterophile antibodies
|
|
Pathogenesis of CMV
|
Infects salivary epithelial cells and latency in mononuclear cells (Owl eye inclusions)
|
|
Pathogenesis of Polio virus
|
Destroys anterior horn motor neurons
|
|
Pathogenesis of Rabies virus
|
Binds peripheral nerves via nicotinic Ach receptor --> retrograde transport to dorsal root ganglia --> brain
|
|
Pathogenesis of Influenza virus
|
Hemaglutinin binds sialic acid on epithelium, hemagglutinates RBCs and induces antibodies. Neuroaminidase cleaves sialic acid with release of virus. Mutations of HA and NA cause genetic drift and epidemics. Genetic reassortment causes genetic shift and pandemics.
|
|
Diseases caused by Parvovirus B19
|
Erythema infectiosum (raised indurated "slapped cheek" facial rash). Hydrops fetalis and spontaneous abortions.
|
|
Diseases caused by HPV
|
Common warts (2, 4); Plantar warts (1); Condylomata acuminata; Benign genital warts (6, 11)(90%); Cervical intraepithelial neoplasia (16, 18). Find koilocytic cells in biopsy or PAP. DNA probes and PCR to determine strain.
|
|
Diseases caused by HSV-1 and HSV-2
|
Gingivostomatitis and cold sores (latent in trigeminal mucosa); Painful genital vesicles (latency in sacral ganglia); Keratoconjunctivitis; Meningoencephalitis (focal temporal lessions); Neonatal herpes (passage through birth canal, disseminated, liver and encephalitis involvement). Tzanck smear shows multinucleated giant cells.
|
|
Chickenpox
|
VZV. Fever, pharyngitis, asynchronous rash.
|
|
Shingles
|
VZV. Pain and vesicles restricted to one dermatome in the 5th or 6th decade. Reactivation of latent infection.
|
|
Heterophile+ mononucleosis
|
EBV. Generalized teder lymphadenopathy, splenomegaly with latency in B cells. Atypical lymphocytes and heterophile antibodies that agglutinate cow and sheep RBCs.
|
|
Malignancies by EBV
|
Burkitt's lymphoma: t(8:14) mandible or abdomen; Hodgkin lymphoma; Nasopharyngeal CA.
|
|
Heterophile- mononucleosis
|
CMV. Generalized tender lymphadenopathy, splenomegaly, Owl-eye inclusions
|
|
Cytomegalic inclusion disease
|
CMV. MC in-utero infection in US. Jaundice, hepatosplenomegaly, thrombocytic purpura, pneumonitis, CNS damage
|
|
CMV infections in immunocompromised
|
Interstitial pneumonitis, systemic infection in AIDS and transplant patients. CMV retinitis in AIDS patients.
|
|
Roseola
|
HHV-6. Fever for 3-5 days followed by a non-pruritic maculopapular rash in the trunk.
|
|
Kaposi sarcoma
|
Malignancy of epithelial cells caused by HHV-8 which has a gene that turns on VEGF. Seen in AIDS.
|
|
Diseases caused by adenovirus
|
ARD and pneumonia in military recruits, college students associated to crowded quarters. Non-purulent pharyngoconjunctivitis (swimmers, sore throat coryza, red eyes) and keratoconjunctivitis (shipyard workers)
|
|
Diseases caused by Poxviruses
|
Variola (prodrome followed by synchronous rash and guarnieri intracytoplasmic inclussions); Molluscum contagiosum (umbilicated warts).
|
|
Diseases caused by Norwalk virus
|
Acute gastroenteritis. Watery diarrhea, nausea, vomiting. Associated to outbreak in cruise ships.
|
|
Polio
|
Destroys anterior horn motor neurons. Flaccid paralysis without sensory loss. Live vaccine (Sabin), killed vaccine (Salk)
|
|
Diseases caused by Coxsackie viruses
|
Aseptic meningitis, herpangina, myocarditis. Associated with type I DM and dilated cardiomyopathy.
|
|
MCC common cold
|
Rhinovirus, followed by coronavirus.
|
|
Infectious hepatitis
|
HAV. Fever, malaise, headache, vomiting, coluria, jaundice.
|
|
Culex mosquito
|
SLE, WNV.
|
|
Aedes mosquito
|
Dengue, YFV
|
|
Dengue
|
Fever, myalgia, arthralgia, petechiae, thrombocytopenia, neutropenia.
|
|
Yellow fever
|
Fever, jaundice, black vomit
|
|
Causes of encephalitis
|
SLE, WNV, EEE, WEE, VEE, CMV
|
|
Causes of asceptic meningitis
|
Coxsackie
|
|
German measles
|
Rubella. Erythematous maculopapular rash from face to torso. No koplik spots.
|
|
SARS
|
SARS-CoV. Atypical pneumonia with dry cough, dyspnea, hypoxia, acute respiratory distress. Travel to Far East or Toronto.
|
|
AIDS gag gene
|
Encodes p24 capsid protein and p17 matrix protein
|
|
AIDS pol gene
|
Encodes reverse transcriptase (genetic drift of env gp), integrase (integrates DNA into genome), protease
|
|
AIDS env gene
|
Encodes gp160 which is cleaved to gp120 (binds CD4, CCR5, CXCR4) and gp41 (viral fusion)
|
|
AIDS tat gene
|
Upregulates transcription
|
|
Life cycle of AIDS virus
|
gp120 binds CD4/CCR5/CXCR4; endocytosis into cell looses envelope; dsDNA is synthesized by reverse transcriptase in cytoplasm; the DNA and integrase move into nucleous and incorporated into host genome forming provirus; transcription and translation; virus assembly and release taking host cell membrane and viral glycoproteins
|
|
Homozygous CCR5 mutation
|
Immune to HIV infection
|
|
Heterozygous CCR5 mutation
|
Slow course of AIDS
|
|
CXCR1 mutation
|
Rapid progression to AIDS
|
|
Symptomatic HIV infections
|
Bacillary angiomatosis, oral or vulvovaginal candidiasis, cervical dysplasia, hairy leukoplakia, ITP, listeriosis, PID, peripheral neuropathy
|
|
AIDS-defining conditions
|
Encephalopathy, recurrent pneumonia, fungal infections, esophageal or lung candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, pneumoccystis jiroveci pneumonia, Kaposi sarcoma, Burkitt Lymphoma, CMV retinitis, cryptosporidiosis, isosporiasis, toxoplasmosis, mycobacterium TB or avium
|
|
AIDS infections with <400 CD4
|
Oral thrush, tinea pedis, shingles, TB, bacterial infections
|
|
AIDS infections with <200 CD4
|
Cryptosporidiosis, isosporidiosis, coccidiodomycosis, pneumocystis jiroveci
|
|
AIDS infections with <100 CD4
|
Candida esophagitis, toxoplasmosis, histoplasmosis
|
|
AIDS infections with <50 CD4
|
CMV retinitis and esophagitis, disseminated M. avium, cryptococcal meningoencephalitis
|
|
Measles
|
Cough, coryza, conjunctivits, photophobia, Koplik spots, maculopapular rash from face down. Complication: SSPE
|
|
Mumps
|
Bilateral parotitis, fever, headache, swelling or parotids. Complications: pancreatitis, orchitis, infertility
|
|
Croup
|
Parainfluenza. Barking cough, inspiratory stridor, hoarseness.
|
|
MCC pneumonia in children 1m-18yr
|
Atypical pneumonia by RSV.
|
|
Rabies
|
Hydrophobia, seizures, hallucinations, coma, death. Associated with bat or dog bites. Negri bodies.
|
|
Influenza
|
Fever, chills, bronchiolitis, vomiting, croup, pneumonia. Can lead to Reye or Guillain-Barre.
|
|
MCC of infantile gastroenteritis
|
Rotavirus
|
|
Viral genetics: phenotypic masking
|
Two virus infect a cell. The surface proteins of one virus (A) coat the genome of the other (B). The surface proteins of A determine infectivity while the viral progeny will have the genome of B.
|
|
Viral genetics: recombination
|
Exchange of genes between 2 chromosomes
|
|
Viral genetics: reassortment
|
Genetic shift. Two strains of a segmented virus coinfect a cell and recombine to produce a new progeny. Responsible for pandemics.
|
|
Viral genetics: complementation
|
One virus with a defective gene is complemented by another virus with working gene after they both coinfect a cell. Example: coinfection with HBV and HDV.
|
|
Characteristics of Malassezia furfur
|
Normal skin flora. Yeast clusters and short curved hyphae on KOH mount. "Spaghetti and meatballs" appearance.
|
|
Characteristics of dermatophytes
|
Filamentous monomorphic fungi. KOH mount shows arthroconidia and hyphae.
|
|
Types of dermatophytes
|
Microsporum, Trichophyton, Epidermophyton
|
|
Characteristics of Sporothrix schenckii
|
Hyphae with rosettes and sleeves of conidia in the envirenment. Cigar-shaped yeast in tissue
|
|
Characteristics of Histoplasma capsulatum
|
Hyphae with microconidia and tuberculate macroconidia in environment. Small intracellular yeasts inside macrophages.
|
|
Characteristics of Coccidioides immitis
|
Hypahe breaking up into arthroconidia is environmental form. Spherules with endospores is tissue form.
|
|
Characteristics of Blastomyces dermatitidis
|
Hyphae with nondescript conidia is environmental form. Broad-based budding yeats with double refractile cell wall in tissue.
|
|
Characteristics of Aspergillus fumigatus
|
Monomorphic fungus with septate hyphae and dichotomous branches at 45 degree angles
|
|
Characteristics of Candida albicans
|
Yeast is normal flora of mucous membranes. Germ tubes in serum. Pseudohyphae and true hyphae in tissues.
|
|
Characteristics of Cryptococcus neoformans
|
Encapsulated monomorphic yeast on India ink. Capsular "halo" in CSF sample.
|
|
Characteristics of Mucor
|
Nonspetate hyphae with 90 degree angle branches
|
|
Characteristics of Pneumocystis jirovenci
|
Obligate extracellular parasite shows silver-staining cysts in tissues.
|
|
Eastern Great Lakes
|
Histoplasma capsulatum
|
|
Ohio river valley
|
Histoplasma capsulatum, Blastomyces dermatitidis
|
|
Mississippi river valley
|
Histoplasma capsulatum, Blastomyces dermatitidis
|
|
Missouri river valley
|
Histoplasma capsulatum, Blastomyces dermatitidis
|
|
Southern California
|
Coccidioides immitis
|
|
Arizona
|
Coccidioides immitis
|
|
New Mexico
|
Coccidioides immitis
|
|
Texas
|
Coccidioides immitis
|
|
Nevada
|
Coccidioides immitis
|
|
Michigan
|
Blastomyces dermatitidis
|
|
Northern Minnesota
|
Blastomyces dermatitidis
|
|
North Carolina
|
Blastomyces dermatitidis
|
|
South Carolina
|
Blastomyces dermatitidis
|
|
Central America
|
Blastomyces dermatitidis
|
|
Pityriasis/tinea versicolor
|
Malassezia furfur. Superficial infection of keratinized cells in moist, warm temperature. Hypopigmented spots on the chest and back. Rx.: topical selenium sulfide
|
|
Tinea
|
Scaly, itchy ring-like lessions of the skin. Can also invade scalp, body and feet. Rx.: topical imidazoles.
|
|
Cutaneous sporotrichosis
|
Subcutaneous or lymphocutaneous mycetomas seen in gardeners, florists, basket weavers. Rx.: itraconazole or amphotericin B
|
|
Pulmonary sporotrichosis
|
Pulmonary mycetomas seen in urban homeless alcoholics. Rx.: itraconazole or amphotericin B
|
|
Fungus flu pneumonia
|
H. capsulatum. Histoplasmosis. Can be asymptomatic or pneumonia and hepatosplenomegaly may be present. Associated with spelunking (cave exploring), cleaning chicken coops or bulldozing starling roots. Rx.: ketoconazole, amphotericin B
|
|
Valley fever
|
Coccidioides immitus. Coccidiomycosis. Asymptomatic to self-resolving pneumonia associated with erythema nodosum and arthritis. Can affect immunocompromised patients with pulmonary calcifications or pregnant women in the third trimester. Rx.: amphotericin B.
|
|
Blastomycosis
|
B. dermatitidis. Acute or chronic pulmonary disease. Rx.: amphotericin B/ketoconazole
|
|
Allergic bronchopulmonary aspergillosis
|
A. fumigatus. Asthma and allergies predispose as it grows in mucous plugs
|
|
Fungus ball
|
A. fumigatus. Grows in lung cavitations need to surgically remove.
|
|
Invasive aspergillosis
|
A. fumigatus. Invades tissues causing infarcts and hemorrhage, pneumonia, meningitis or cellulitis. Neutropenia, CGD, CF and burns are predisposing factors. Rx.: amphotericin B
|
|
Candidiasis
|
C. albicans. Oral thrush, esophagitis, gastritis (premature babies, steroid users, AIDS patients, antibiotic overuse). Yeast vaginitis (high pH, diabetics). Rx.: amphotericin B for disseminated, topical azoles/nystatin.
|
|
Cryptococcosis
|
C. neoformans. Meningitis in Hodgkin and AIDS patients. Acute pulmonary infection in pigeon breeders. Rx.: AMB+5 flucytosine
|
|
Rhinocerebral infection
|
Mucor. Paranasal swelling, necrotic tissues and hemorrhagic exudates in ketoacidotic diabetics and leukemic patients. Rx.: amphotericin B
|
|
Pneumocystis pneumonia
|
Atypical pneumonia in AIDS patients. Nonproductive cough, fever, dyspnea, destruction of type I pneumocytes. Patchy infiltrate in x-ray. Rx.: trimethrophrim sulfa
|
|
Normal flora of cutaneous surfaces
|
Staph epidirmidis, staph aureus, strep
|
|
Normal flora of the nose
|
Staph aureus
|
|
Normal flora of the oropharynx
|
Viridans strep, strep mutans, nonpathogenic Neisseria, nontypable H. influenzae
|
|
Colon normal flora
|
anaerobic bacteroides, gram- anaerobic rods
|
|
Normal flora of the vagina
|
Lactobacillus
|
|
Encapsulated bacteria
|
Strep pneumonia, Klebsiella, Haemophilus, Pseudomonas, Neisseria menigitidis, Cryptococcus neoformans. "Some Killers Have Pretty Nice Capsules"
|
|
Teichoic acids
|
Adherence and pathogenicity factor of gram positive bacteria
|
|
Pili/fimbriae
|
Adherence and antiphagocytic component of gram negative bacteria (specially N. gonorrehae)
|
|
M protein
|
Strep pyogenes (group A β-hemolytic) antiphagocytic surface component
|
|
A protein
|
Staph aureus virulence factor binds Fc portion if IgG and inhibits opsonization and phagocytosis
|
|
IgA protease
|
Destructs mucosal IgA. Produced by Neisseria, Haemophilus, S. Pneumoniae
|
|
LPS
|
Gram negative membrane component endotixin. Heat-stable, not immunogenic. Lipid A is toxic component.
|
|
MOA LPS
|
LPS activates macrophages with release of TNF-α, IL-1 (fever), IL-6, nitric oxide with tissue damage. Damage endothelium releases bradykinin which causes vasodilation and shock. Hageman facctor activates coagulation cascade in DIC. Activates complement C3a (hypotension, edema) and C5a (neutrophil chemotaxis).
|
|
Define: superantigen
|
Crosslinks MHC-II and T-cell receptor simultanously and non-specifically which leads to polyclonal activation of T-cells with massive release of IFN-γ which activates macrophages to release IL-1, TNF-alpha and IL-6 and an exagerated reaction
|
|
Diptheria toxin
|
C. diptheriae. ADP ribosylation and inactivation of EF-2 inibits eukaryotic protein synthesis in throat epithelium, heart, nerves. Causes pharyngitis with a pseudomembrane in throat
|
|
Exotoxin A
|
Pseudomonas. ADP ribosylation and inactivation of EF-2 inibits eukaryotic protein synthesis mainly in hepatocytes
|
|
Shiga toxin
|
Shigella. Cleaves 60S ribosomal subunit, inhibits protein synthesis
|
|
Verotoxin
|
E.coli O157. Cleaves 60S ribosomal subunit, inhibits protein synthesis. Causes HUS
|
|
Tetanus toxin
|
C. tetani. Blocks release of inhibitory neurotransmitters GABA and glycine. Lockjaw, muscle spasms
|
|
Botulinum toxin
|
C. botulinum. Blocks release of Ach causing anticholinerginc symptoms, flaccid paralysis. Spores found in honey.
|
|
TSST-1
|
Staph aureus superantigen causes toxic shock syndrome (fever, rash, shock)
|
|
Enterotoxin
|
Staph aureus. Food poisoning 2-6 hours after ingestion of mustards.
|
|
Strep exotoxin A
|
Erythrogenic toxin. Causes toxic shock-like syndrome (fever, rash, shock) and cardiotoxicity
|
|
Heat labile toxin
|
Enterotoxigenic E. coli. Stimulates Adenylate cyclase by ADP ribosylation, increases cAMP. Secretory watery "traveler's" diarrhea. "Labile like the Air, stable like the Ground"
|
|
Heat stable toxin
|
Enterotoxigenic E. coli. Stimulates Guanylate cyclase by ADP ribosylation increases cAMP. Secretory watery diarrhea. "Labile like the Air, stable like the Ground"
|
|
Cholera toxin
|
Vibrio cholera. ADP ribosylateion of Gs stimulates adenylate cyclase and cAMP increasing Cl- secretion and decreasing Na+ reabsorption in the intestines. Causes profuse "rice water" diarrhea.
|
|
Anthrax toxin
|
Bacillus anthracis. EF component is an adenylate cyclase, increases cAMP. Causes edema and cell lysis
|
|
Pertussis toxin
|
Bordetella pertussis/ ADP ribosylates Gi, the negative inhibitor of adenylate cyclase, increasing cAMP. Whooping cough, lymphocytosis, hypoglycemia
|
|
Perfringens α-toxin
|
C. Perfringens. Lecithinase causes myonecrosis and gas gangrene. Double zone of hemolysis on blood agar
|
|
Gram positive cell envelope components
|
Capsule; thick peptidoglycan cell wall gives rigid support and protects from osmotic damage; teichoic acids; cytoplasmic inner membrane
|
|
Gram negative cell envelope components
|
Capsule; Outer membrane contains LPS/lipid A; thin prptidoglycan cell wall; periplasmic space contains β-lactamases; inner cell membrane
|
|
Describe the Gram stain
|
Crystal violet and Gram's iodine stain dark blue; acetone washes it off from gram negatives; safranin stains gram negatives red
|
|
Describe Ziehl-Neelsen acid fast stain
|
Carbol fuchsin with heat stains red; acid alcohol washes it off from non-acid fast; methylene blue stains non-acid fast blue
|
|
Culture media: Corynebacterium
|
Loffler's, tellurite
|
|
Culture media: lactose-fermenting enterobacteria
|
Pink colonies on MacConkey's agar. "Lactose is the Key"
|
|
Culture media: vibrio cholerae
|
Alkaline TCBS
|
|
Culture media: legionella
|
Charcoal-yeast extract with cysteine
|
|
Culture media: Mycobacterium
|
Lowenstein-Jensen medium
|
|
Culture media: Neisseria and Haemophilus
|
Chocolate agar with factors V and X
|
|
Culture media: Neisseria from sites with normal flora
|
Thayer-Martin selective medium
|
|
Obligate aerobes
|
Nocardia, Pseudomona, Mycobacterium tuberculosis, Bacillus. "Nagging Pests Must Breathe"
|
|
Obligate anaerobes
|
Actinomyces, Bacteroides, Clostridium. "Anaerobes know their ABCs"
|
|
Intracellular pathogens
|
Rickettsia, chlamydia
|
|
Urease-positive bugs
|
H. pylori, proteus, klebsiella, ureaplasma
|
|
Characteristics of Staph aureus
|
Gram+ cocci in clusters, catalase+, coagulase+, β hemolytic, ferments mannitol, salt tolerant
|
|
Characteristics of Staph epidirmidis
|
Gram+ cocci in clusters, catalase+, coagulase-, novobiocin sensitive
|
|
Characteristics of Staph saprophyticus
|
Gram+ cocci in clusters, catalase+, coagulase-, novobiocin resistant
|
|
Characteristics of S. pneumoniae
|
Gram+ catalase- lancet-chapes diplococci in chains, α hemolytic, "MOPS" optochin sensitive, bile soluble, +quellung
|
|
Characteristics of Viridans strep
|
Gram+ catalase- cocci, α hemolytic, optochin resistant, bile insoluble
|
|
Characteristics of S. pyogenes
|
Gram+ catalase- cocci, group A, β hemolytic, bacitracin sensitive, PYR+
|
|
Characteristics of S. agalactiae
|
Gram+ catalase- cocci, group B, β hemolytic, bacitracin resistant, cAMP test+
|
|
Characteristics of Enterococcus
|
Gram+ catalase- cocci, PYR+, hydrolizes esculin in 40% bile and 6.5% NaCl
|
|
Characteristics of Clostridium tetani
|
Gram+ spore-forming anaerobic rods
|
|
Characteristics of Clostridium botulinum
|
Gram+ spore-forming anaerobic rods
|
|
Characteristics of Clostridium perfingens
|
Gram+ spore-forming anaerobic rods, double zone of β hemolysis
|
|
Characteristics of Clostridium difficile
|
Gram+ spore-forming anaerobic rods
|
|
Characteristics of Corynebacterium diptheriae
|
Gram+ aerobic club-shaped rods, V or L shapes on tellurite, metachromatic granules on Leoffler. β-prophage contains diptheria toxin gene (lysogeny)
|
|
Characteristics of Bacillus
|
Gram+ spore-forming aerobic rods
|
|
Characteristics of Listeria
|
Gram+ rods with tumbling or actin jet motility, β hemolytic, cold growth, facultative intracellular
|
|
Characteristics of Actinomyces
|
Gram+, long branching filaments, non-acid fast anaerobic rods
|
|
Characteristics of Nocardia
|
Gram+, long branching filaments, partially acid-fast aerobic rods
|
|
Characteristics of Mycobacterium tuberculosis
|
Acid-fast aerobic rods on Lowenstein-Jensen medium, auramine-rhodamine stainning (fluorescent apple green). Mycolic acid lipids on cell wall
|
|
Characteristics of Mycobacterium lepreae
|
Acid-fast aerobic rods, can't be cultured (obligate intracellular). Mycolic acid lipids on cell wall
|
|
Characteristics of Neisseria meningitidis
|
Gram- kidneybean-shaped diplococci, grows on chocolate agar, maltose fermenter, polysaccharide capsule
|
|
Characteristics of Neisseria gonorrhoeae
|
Gram- kidneybean-shpaed diplococci, growws Thayer-Martin, maltose non-fermenter, no polysaccharide capsule
|
|
Characteristics of Haemophilus influezae
|
Gram- cocobacillus, requires factor X and V (chocolate agar). Satellite phenomenon near staph aureus on blood agar
|
|
Characteristics of Pasteurella
|
Gram- cocobacillus, anaerobic
|
|
Characteristics of Brucella
|
Gram- cocobacillus, aaerobic, zoonosis, biowarfare
|
|
Characteristics of Bordetella pertussis
|
Gram- aerobic cocobacillus
|
|
Characteristics of Klebsiella
|
Gram- lactose-fermenting rods on MacConkey, polysacchride capsule, oxidase-
|
|
Characteristics of E. coli
|
Gram- lactose-fermenting rods on MacConkey, oxidase-
|
|
Characteristics of Shigella
|
Gram- nonlactose-fermenting rods on MacConkey, nonmotile, no H2S production, oxidase-
|
|
Characteristics of Salmonella
|
Gram- nonlactose-fermenting rods on MacConkey, highly motile, H2S producer, oxidase-
|
|
Characteristics of Proteus
|
Gram- nonlactose-fermenting rods with swarming motility, H2S producer, urease+, oxidase-
|
|
Characteristics of Pseudomonas
|
Gram- nonlactose-fermenting rods on MacConkey oxidase+, aerobic, produces green pigment pyocyanin
|
|
Characteristics of C. jejuni
|
Gram- nonlactose-fermenting curved rods with flagella, oxidase+, microaerophillic
|
|
Characteristics of H. pylori
|
Gram- nonlactose-fermenting helical rods with flagella, oxidase+, urease+, microaerophillic
|
|
Characteristics of Vibrio cholera
|
Gram- nonlactose-fermenting curved rod with flagella, oxidase+ grows on alkaline media (thiosulfate)
|
|
Characteristics of Francisella
|
Gram- facultative intracellular rods, zoonosis, biowarfare
|
|
Characteristics of Yersinia
|
Gram- coagulase+ rods with bipolar stainnning, facultative intracellular, zoonosis
|
|
Characteristics of Gardnerella
|
Gram variable rod, positive whiff fishy smell test
|
|
Characteristics of Bacteroides
|
Gram- anaerobic rod
|
|
Characteristics of Treponema
|
Gram- spirochete, spiral-shaped with axial filaments, dark microscopy
|
|
Characteristics of Borrelia
|
Gram- spirochete, spiral-shaped with axial filaments, microaerophilic
|
|
Characteristics of Leptospira
|
Gram- spirochete, spiral question mark-shaped with axial filaments
|
|
Characteristics of Rickettsia
|
Gram- (doesn't stain well) obligate intracellular rods
|
|
Characteristics of Coxiella
|
Gram- (doesn't stain well) obligate intracellular rods
|
|
Characteristics of Chlamydia
|
Obligate intracellular bug seen in Giemsa stain. Wall lacks muramic acid. Elementary body is infective, reticulate bodies are replicating in the cell
|
|
Characteristics of Mycoplasma
|
Lacks peptidoglycan cell wall, does not gram stain. Cholesterols in membrane
|
|
Staph gastroenteritis
|
Nausea, abdominal pain, vomiting, followed by diarrhea 2-6 hours after ingesting enterotoxin in custards, pastries, potato salad, canned meats
|
|
Infective acute endocarditis
|
Staph aureus. Fever, malaise, leukocytosis, murmur
|
|
Abscess and mastitis
|
Staph aureus. Pain, pus, redness, edema, warmth.
|
|
Toxic shock syndrome
|
Staph aureus or GAS. Fever hypotension, scarlatiform desquamating rash on palms and soles, multiorgan failure. Produced by superantigen TSST-1 toxin
|
|
Impetigo
|
Staph aureus or GAS. Erythematous papules to bullae (staph) or honey-crusted lessions (GAS)
|
|
Staph pneumonia
|
Typical acute severe pneumonia. Associated to Ccystic Phibrosis, CGD
|
|
MCC surgical infections
|
Staph aureus. Fever with cellulitis or abscess
|
|
MCC osteomyelitis
|
Staph aureus. Bone pain, fever, inflammation, lytic bone lessions on x-rays
|
|
"Honeymoon" cystitis
|
Staph saprophyticus. 2nd MCC UTI in sexually active women. Dysuria, frequency, urgency, suprapubic pain.
|
|
3 MCC of ambulatory UTIs
|
E. coli, S. saprophyticus, Klebsiella
|
|
Infection of prosthetic devices and catheters
|
Staph. epidirmidis
|
|
Rx.: staph infections
|
Nafcillin, oxacillin. For MRSA: vancomycin
|
|
Pharyngitis
|
GAS. Abrupt onset of sore throat, fever, tonsillar abscesses, tender anterior cervical nodes. Rx.: penicillin or macrolide in case of allergy
|
|
Scarlet fever
|
GAS. Pharyngitis plus sandpaper rash (palm and soles spared), strawberry tongue, nausea
|
|
Rheumatic fever
|
Antibodies against GAS M protein cross-react with heart two weeks after a pharyngitis (Type II hypersensitivity). Jones major criteria: Fever, subcutaneous nodules, polyarthritis, carditis, erythema marginatum, chorea.
|
|
Acute postsrep glomerulonephritis
|
GAS M12 serotype. Immunocomplex deposition on GBM (type III hypersensitivity). Nephritic syndrome: hypertension, azotemia, edema, smoky urine (hematuria).
|
|
3 MCC of neonatal meningitis
|
GBS agalactiae, E. coli, Listeria
|
|
Diseases caused by Strep pneumoniae
|
MOPS: Meningitis, Otitis media (in children), Penumonia, Sinusitis; sepsis in asplenic sickle cell anemia.
|
|
Strep pneumonia virulence factors
|
Polysacchride capsule is major factor, IgA protease cleaves mucosal IgA, teichoic acids and peptidoglycan are highly inflammatory in CNS
|
|
Clinical features of typical pneumonia and Rx.
|
High fever, dyspnea, tachypnea, pleuritic chest pain, productive rusty sputum cough, lobar consolidation on x-ray. Rx.: macrolides
|
|
Pathophysiology of Strep. Viridans infection
|
Dextran biofilm mediated adherence to teeth or fibrin deposits in damaged/prosthetic heart valve and growth in vegetations. Causes dental caries and subacute endocarditis.
|
|
Subacute bacterial endocarditis
|
Strep viridans following dental work. "FROM JANE": fever, Roth retinal lessions, Osler painful nodules, murmur, Janeway painless lessions, anemia, nailbed hemorrhages, emboli. Rx.: penicillin G with aminoglycosides
|
|
Disease caused by enterococcus
|
Urinary/billiary tract infections and subacute bacterial endocarditis following prostate or GI surgery
|
|
Malignant pustule
|
Cutaneous anthrax by B. anthracis. Painless ulcer papule with vesicles have a central eschar necrosis with erythematous border and painful regional lymphadenopathy
|
|
Wool sorter's disease
|
Life-threatening pneumonia by B. anthracis on contact with animal hides. Cough, fever, facial edema, dyspnea, diaphoresis, cyanosis and shock with mediastinal hemorrhagic lymphadenitis
|
|
Bacillus gastroenteritis
|
Rapid onset gastroenteritis with watery diarrhea associated with reheated fried rice
|
|
Tetanus
|
C. tetani. Risus sardonicus (lock jaw), opisthotonus, extreme muscle spasms caused by tetanosmin block of inhibitors glycine and GABA. Rx.: Hyperimmune gamma globulin, metronidazole, diazepam
|
|
Disease caused by C. botulinum
|
"Floppy baby" flaccid paralysis by botulinum toxin block of acetylcholine at neuromuscular junction. Flaccid paralysis, diplopia, dysphagia, disphonia. Associated with honey and canned vegetables
|
|
Gas gangrene
|
C. perfringes. Dirty wound with increasing pain, edema, gas, fever and tachycardia. Caused by alpha toxin which is a lecithinase that lyses tissue
|
|
Clostridium food poisoning
|
Enterotoxin in reheated meat dishes causes noninflammatory watery diarrhea in 8-24 hours
|
|
Pseudomembranous colitis
|
C. difficile enterotoxin damages mucosa. Diarrhea, colitis, pseudomembrane. Associated with clindamycin use in hospitalized patients. Tx.: metronidazole
|
|
MCC of meningitis in renal transplant or cancer patients
|
Listeria
|
|
Granulomatosis infactisepticum
|
Neonatal sepsis with disseminated granulomas after in-uterus transmission of Listeria. Associated with unpasterurized milk products, cold deli meats, soft cheeses.
|
|
Diptheria
|
Diptheria toxin inhibits EF-2 and protein synthesis. Causes pharyngitis with gray pseudomembrane. Complications are larynx obstruction, myocarditis, recurrent laryngeal nerve palsy
|
|
Actinomycosis
|
Oral/facial draining abscesses with sinus tracts in tissues with low oxygenation: cervicofacial, pelvic, solitary brain abscess
|
|
Nocardiosis
|
Cavitary pulmonary mycetomas in immunocompromised and cancer patients. Cough, fever, dyspnea, cavitations.
|
|
Pathophysiology of tuberculosis
|
Primary TB: replication in macrophages with subsequent CMI produces Gohn focus which is transported to hilar lymph nodes remaining latent. Secondary TB: a reinfection or immunocrompromise produces granulomas and cavitary lessions or disseminated milliary TB (CNS, vertebrae, kidneys GI).
|
|
M. tuberculosis pathogenic factors
|
Sulfatides in cell envelope inhibit phagosome lysosome fusion. Tuberculin induces CMI with casseating granulomas.
|
|
Clinical features of TB
|
Chronic productive cough, hemoptysis, weight loss
|
|
Leprosy
|
M. leprae invades nerve endings producing a strong CMI with granulomas (tuberculoid leprosy) or a weak CMI in which theres bacterial damage to nerves. Paresthesia (leads to trauma and burns), loss of eyebrows, destruction of nasal septum, lumpy ears, leonine features.
|
|
Meningococcus virulence factors
|
Polysacchride capsule is antiphagocytic; IgA protease allow oropharynx colonization; endotoxin leads to septic shock in meningococcemia; deficiency of C5-C8 predisposes to bacteremia
|
|
Meningococcemia and meningitis
|
N. meningitidis. Abrupt onset of fever, chills, prostration and petecchial rash, nuchal rigidity. CSF: high pressure, high neutrophils, high protein, low glucose.
|
|
Waterhouse-Friderichsen syndrome
|
Meningococemia leads to ecchymoses, DIC, bilateral adrenal infarct, shock, death.
|
|
Diseases caused by N. gonorrheae
|
Uretheral/vaginal leukorrhea; endocervicitis/PID; septic arthritis; neonatal opthalmia
|
|
Diseases caused by pseudomonas
|
"PSEUDOmonas": Pneumonia in CF and CGD; Sepsis with black necrotic lessions; External otitis "swimmer's ear"; UTI in catheterized patients; Diabetes and Drug-user Osteomyelitis. Associated with burns and wound infections; associated with respirators, humidifiers and water.
|
|
Legionnaires disease
|
Legionella. Atypical pneumonia associated with old age, immunosuppressed, smokers, water aerosols and air conditioning systems.
|
|
Tularemia
|
Francisella. Dermacentor tick bite produces ulceroglandular disease with ulcer at bite site and lymph node enlargement and necrosis. Associated with rabbit skinning in Arkansas and Missouri.
|
|
Whooping cough
|
B. pertussis. Repetitive cough with inspiratory whoops, anoxia and eye hemorrhages in unvaccinated children
|
|
Brucellosis/undulant fever
|
Brucella. Acute septicemia with high fever, profuse sweating and hepatomegaly. Associated with slaughterhouse animals and unpasteurized dairy products in California, Texas or travel to Mexico
|
|
Campylobacter gastroenteritis
|
MCC of inflammatory diarrhea in US. Abdominal pain, vomitting, bloody diarrhea with fecal leukocytes. Complication: Guillain-Barre syndrome due to cross-reactivity between Campylobacter oligosacchrides and neural glycosphingolipids.
|
|
Guillain-Barre syndrome
|
Inflammatory demyelinating polyneuropathy caused by antibodies against Campylobacter (or other agents) cross reacting with neural glycosphingolipids. Acute onset of ascending paralysis with areflexia.
|
|
Helicobacter virulence factors
|
Motile flagella; Urease covers the bug in ammonium which neutralizes stomach acid; Mucinase aids in penetrating the mucin layer of stomach.
|
|
Diseases associated with Helicobacter
|
Chronic gastritis and 90% of duodenal peptic ulcers; gastric adenocarcinoma., gastric MALToma
|
|
E. coli serotypes
|
"PITCH": EPEC (enteropathogenic=pediatric); EIEC (enteroinvasive=inflammatory diarrhea); ETEC (enterotoxigenic=traveler's diarrhea); EHEC (enterohemorrhagic=undercooked hamburgers)
|
|
MCC UTI
|
E.coli. Colonization of uroepithelium from fecal flora. Pyelonephritis-associated pilli (p. pili) is major virulence factor and allows adherence to uroepithelium
|
|
2nd MCC neonatal septicemia
|
E. coli from maternal fecal flora infects neonate during parturition. K1 serotype capsule and endotoxin are virulence factors
|
|
3 MCC nosocomial UTIs
|
E. coli, proteus, klebsiella
|
|
MCC gram- sepsis
|
E. coli. From indwelling IV catheters
|
|
Traveler's diarrhea
|
E coli. Associated with travel to third-world countries and children < 3 in third-world countries. Watery diarrhea produced by LT and ST toxins that stimulate adenylate cyclase and guanylate cyclase increasing cAMP.
|
|
2nd MCC of infantile diarrhea
|
EPEC (enteroPathogenic=Pediatric). Noninflamatory watery diarrhea in babies in developing countries. Adherance to M cells is virulence factor.
|
|
Diseases by EHEC
|
Bloody diarrhea without leukocytes in stool or fever (distinguishes from shigellosis). Can cause HUS. Verotoxin shiga-like toxin inhibits protein synthesis by interfering with 60S ribosomal subunit.
|
|
Disease caused by EIEC
|
Watery inflammatory diarrhea with fever and fecal leukocytes
|
|
Shigella virulence factors
|
Endotoxin; invasion of M cells and polymeriazation of actin jet trails produce shallow ulcers; shiga toxin inhibits protein synthesis by interfering with 60S ribosomal subunit
|
|
Shigellosis
|
1-10 acid-resistant organisms needed for infection. Invasive bloody diarrhea with fever, abdominal cramps, tenesmus.
|
|
Diseases caused by K. pneumoniae
|
Typical pneumonia in alcoholics and diabetics with currant-jelly bloody sputum and lung abscesses. Nosocomial UTIs (3rd MCC) related with catheters. Septicemia in immunocompromised patients.
|
|
Granuloma inguinale
|
Subcutaneous nodules on genitals with bleeding ulcers. Caused by K. granulomatis. Associated with Caribbean and New Guinea patients. Donovan bodies encapsulated bacteria inside macrophages
|
|
Typhoid fever
|
Salmonella typhi. Large number of organisms ingested infect ileocecal region cause constipation. Bacteria reach basolateral side of M cells, lymph nodes and blood with positive blood culture at 1 week. Infection of liver and spleen with fever, headache and septicemia. 85% of stool cultures postive by week 3. Complication: necrosis and perforation of Peyer patches.
|
|
MCC inflammatory diarrhea
|
Campylobacter, salmonella enterica
|
|
MCC infantile diarrhea
|
Rotavirus, EPEC
|
|
Diseases caused by Salmonella enterica
|
Gastroenteritis with nausea, vomiting, abdominal pain, occasionally bloody stools; MCC osteomyelitis in sickle cell anemia patients. Associated with reptile pets and poultry.
|
|
Bubonic plague
|
Yersinia pestis. Rapidly increasing fever, regional buboes, conjunctivitis, pneumonia. Highly contagious zoonosis associated with rodents and prairie dogs.
|
|
Yersinia enterocolitis
|
Inflammatory bloody diarrhea, fever, pseudoappendicitis. Associated with cold northern climates (Michigan, Scandinavia), unpasteurized milk and pork, pet puppies.
|
|
Disease associated with proteus
|
2nd MCC nosocomial UTIs, struvite renal stones due to urease.
|
|
Weil-Felix reaction
|
Anti-rickettsial antibodies cross-react with proteus antigens. Positive for Rocky Mountain spotted fever (ricketsia rickettsi) and typhus (rickettsia typhi). Negative for Q fever (coxiella)
|
|
Gardnerella vaginosis
|
Vaginal fishy odor and thin gray vaginal discharge. Caused by reduction of vaginal Lactobacillus when vaginal pH > 4.5. Find clue cells.
|
|
Cholera
|
Vibrio cholerae. Profuse rice watery diarrhea and dehydration. Cholera toxin ADP ribosylates Gs increasing adenylate cyclase and cAMP with efflux of Cl- and H2O.
|
|
Disease caused by Pasteurella
|
Cellulitis and lymphadenitis associated with cat bites
|
|
Disease caused by Haemophilus influenzae
|
"haEMOPhilus": Epiglotitis (MCC); Meningitis in unvaccinated children (MCC); Otitis media; Pneumonia in COPD patients.
|
|
Painful chancroid
|
Haemophilus ducreyi. Chancroid and soft painful genital ulcers
|
|
Diseases caused by Bacteroides
|
Septicemia, peritonitis, abdominal abscess after trauma or emergency abdominal surgery
|
|
Primary syphilis
|
T. pallidum. Painless indurated chancre, highly contagious, heals in 3-6 weeks.
|
|
Secondary syphilis
|
T. pallidum. Condylomata lata flat wartlike perianal and mucous membrane lessions, highly contagious. Maculopapular rash
|
|
Tertiary syphilis
|
T. pallidum. Gumman (syphilitic granulomas); aortitis and syphilitic aneurysms (obliterative endarteritis of vasa vasorum); tabes dorsalis (ataxia, Romberg+); "Prostitute" pupil "accomodates but does not react"
|
|
Congenital syphilis
|
Stillbirth, keratitis, deafness, desquamating maculopapular rash
|
|
VDRL test
|
Antitreponemal antibodies in 1ary and 2dary syphilis cross-react with cow heart antigens. Sensitive but not specific.
|
|
FTA-ABS test
|
Fluorescent antibodies agglutinate treponema sample. Specific for syphilis.
|
|
Lyme disease
|
Ixodes deer ticks transmit Borrelia. Bull's eye erythema migrans; severe headache, meningitis, Bell palsy; arrhythmias and miocarditis; migratory poliarthritis. Associated with northeastern states.
|
|
Leptospirosis
|
Myalgia, abdominal pain, hepatitis with combined jaundice. Associated with urine-contaminated waters (jet skiers and sewer workers)
|
|
Rocky Mountain spotted fever
|
R. rickettsii transmitted by tick dermacentor. Fever, headache and maculopapular to petechial rash begins in wrists and ankles and spreads to trunk (centripetal rash). Associated with east coast mountains. Weil-Felix+
|
|
Q fever
|
Coxiella. Fever, pneumonia and granulomatous hepatitis. Weil-Felix negative
|
|
MCC of bacterial STD
|
Chlamydia trachomatis serotypes D-K
|
|
Diseases caused by chlamydia trachomatis
|
Serotypes D-K cause urethritis, cervicitis, PID and infertility, inclusion conjunctivitis; Lymphogranuloma venereum and genital elephatiasis in Africa, Asia, South America. Serotypes A, B, C follicular conjunctivitis with corneal scarring and blindness.
|
|
3 MCC of atypical pneumonia
|
Mycoplasma, Legionella, Chlamydia pneumoniae
|
|
Walking pneumonia
|
Mycoplasma. MCC of pneumonia in adults 18-40 years. Atypical pneumonia with persistent hacking cough and no sputum.
|
|
What is a plasmid?
|
Extra chromosomal genetic elements non-essential for life. Contain genes for fertility, antibiotic resistance and exotoxins.
|
|
What is a bacteriophage?
|
Prophage (bacterial virus) DNA is stable inside the bacterial chromosome (temperate phage). Usually encodes virulence factors such as exotoxins. Temperate phages = lysogeny.
|
|
What is a transposon?
|
Mobile genetic elements (jumping genes). From plasmid to chromosome or vice versa. Ususally associated with multiple drug resistance genes.
|
|
What is homologous recombination?
|
Incorporates and stabilizes genes acquired by transformation, conjugation or transduction. A linear sequence of DNA is exchanged into a homologous or similar sequence of the bacterial chromosome. DNA outside the bacterial chromosome is lost.
|
|
What is site-specific recombination?
|
Integration of circular pieces of DNA (plasmids, phages, transposons) into the bacterial chromosome. No homology is required, no DNA is lost.
|
|
What is transformation?
|
DNA is taken up from the environment by competent bacteria and incorporated by homologous recombination.
|
|
F+ x F- conjugation
|
F+ contains conjugation genes. Sex pilus coded by F+ plasmid tranfers plasmid to F- cell. No chromosomal genes are transferred.
|
|
Hfr x F- conjugation
|
Hfr cell has plasmid integrated into the chromosomal DNA which is transferred to F- cell along with chromosomal DNA.
|
|
Generalized transduction
|
A lytic phage acquires some bacterial DNA and carries to the next bacteria after lysis. Any gene can be transduced.
|
|
Specialized transduction
|
A temperate lysogenic phage carries a mistankenly excised flanking chromosomal gene to the next bacteria. Only specific flanking genes are transferred with phage.
|
|
Autoclave
|
Steam under 15lbs pressure at 121 degrees celsius for 15-20 minutes. Or dry heat for 2 hours at 180 degrees celsius.
|
|
Membrane damaging disinfectants
|
Use for enveloped viruses: detergents (benzalkonium), alcohol, phenols
|
|
Protein denaturing disinfectants
|
Use for naked capsid viruses. Chlorine, iodine, H2O2, formaldehyde, alkylating agents.
|