Microbiology Flashcards

Question

C. diphtheriae culture requirements

Answer 1

Tellurite plate, Loffler's media

Answer 2

Lowenstein-Jensen agar

Answer 3

Eaton's agar

Answer 4

Pink colonies on MacConkey's agar E. coli also grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen

Answer 5

Charcoal yeast extract buffered with cysteine and iron

Answer 6

Sabouraud's agar Sab's a fun guy

Answer 7

Nocardia, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Bacillus Nagging Pests Must Breathe

Answer 8

Clostridium, Bacteroides, Actinomyces Anaerobes Can't Breathe Air Foul-smelling and difficult to culture, produce gas in tissue

Answer 9

They lack catalase and/or superoxide dismutase

Answer 10

Amin(O2)glycosides - require oxygen to enter bacterial cells

Answer 11

Obligate: Rickettsia, Chlamydia (stay inside when it's Really Cold) Facultative: Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis (Some Nasty Bugs May Live FacultativeLY)

Answer 12

Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, Escherichia coli, Salmonella, Klebsiella pneumoniae, group B strep SHiNE SKiS

Answer 13

Positive quellung - swells when anti-capsular antisera are added Quellung = capsular "swellung"

Answer 14

Opsonized and then cleared by spleen Asplenic people have decreased opsonizing ability and thus are at risk for severe infections (need S. pneumonia, H. influenza, and N. meningitidis vaccines)

Answer 15

Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, Serratia You need PLACESS for your "CAT"s

Answer 16

Lets them degrade H2O2 before it can be converted to microbicidal products by myeloperoxidase

Answer 17

Catalase-positive organism NADPH oxidase deficiency

Answer 18

Cryptococcus, H. pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S. epidermidis, S. saprophyticus CHuck norris hates PUNKSS

Answer 19

Actinomyces israelii, S. auerus, Pseudomonas aeruginosa, Serratia marcescens

Answer 20

Yellow sulfur granules composed of filaments of bacteria Israel has yellow sand

Answer 21

Yellow pigment aureus = gold in latin

Answer 22

Blue-green

Answer 23

Red Red marachino (marcescens) cherries

Answer 24

Bacterial virulence factor Binds Fc region of Ig's, prevents opsonization and phagocytosis Expressed by Staph aureus

Answer 25

Bacterial virulence factor Cleaves IgA Secreted by S. pneumoniae, H. influenzae type B, Neisseria (SHiN) to colonize respiratory influenza

Answer 26

Bacterial virulence factor Prevents phagocytosis Express by group A strep

Answer 27

Have to conjugate a protein to the antigen to promote T-cell activation and class switching Antigen alone can't be presented to T cells

Answer 28

Pneumovax (NOT conjugated) vs. Prevnar (conjugated) H. influenzae type B Meningococcal vaccines

Answer 29

Exo: some gram-positive and some gram-negative Endo: nearly all gram-negative (structural component)

Answer 30

Exo: yes Endo: no

Answer 31

Exo: polypeptide Endo: lipopolysaccharide (structural component, released when bacteria is lysed)

Answer 32

Exo: plasmid or bacteriophage Endo: bacterial chromosome

Answer 33

Exo: high Endo: low (need a larger dose)

Answer 34

Exo: various Endo: fever, shock (hypotensive), DIC

Answer 35

Exo: various Endo: induces TNF, IL-1, and IL-6

Answer 36

Exo: induces high-titer antibodies called antitoxins Endo: poorly antigenic

Answer 37

Exo: toxoids Endo: no toxoids formed, no vaccine

Answer 38

Exo: destroyed rapidly at 60 degrees (besides staphylococcal enterotoxin) Endo: stable at 100 degrees for an hour

Answer 39

Exo: tetanus, botulism, diphtheria Endo: meningococcemia, sepsis by gram-negative rods

Answer 40

Ability to take up naked DNA from the environment (competence) S. pneumoniae, H. influenze type B, Neisseria (SHiN - mnemonic also used for IgA protease)

Answer 41

F+ plasmid has genes for sex pilus and conjugation Bacteria without F+ plasmid are F- Plasmid is transfered via pilus (no chromosomal genes)

Answer 42

F+ plasmid can become incorporated into chromosomal DNA (Hfr) Transfer of plasmid and chromosomal genes

Answer 43

Segment of DNA that can jump (excision and insertion) from one location to another Transfer of genes from plasmid to chromosomal DNA and vice versa A way that chromosomal genes can be transferred via conjugation other than Hfr

Answer 44

Packaging event Lytic phage infects bacteria, cleaves DNA and inserts itself Part of chromosomal DNA can become packaged in viral capsid and then transferred to another cell upon the next infection cycle

Answer 45

Excision event Lysogenic phage infects bateria, cleaves DNA and inserts itself Part of chromosomal DNA can become packaged in viral capsid and then transferred to another cell upon the next infection cycle

Answer 46

Deoxyribonuclease (degrades DNA)

Answer 47

Bacitracin sensitive Antibodies to M protein enhance host defenses but can also give rise to rheumatic fever ASO titer detects infection

Answer 48

Bacitracin resistant, beta-hemolytic, hippurate test positive Colonizes vagina Pneumonia, meningitis, sepsis Mainly in babies Screen pregnant women at 35-37 weeks, give intrapartum penicillin prophylaxis if positive

Answer 49

Normal colonic flora Enterococcus faecalis and Enterococcus faecium Penicillin G resistant Cause UTI, biliary tract infections, subacute endocarditis Can grow in 6.5% NaCl and bile

Answer 50

Colonizes the gut Cause bacteremia and subacute endocarditis in colon cancer patients Bovis in the Blood = Cancer in the Colon

Answer 51

Vancomycin-resitant enterococci Cause of nosocomial infection

Answer 52

Produced by group-B strep, enlarges the area of hemolysis caused by S. aureus

Answer 53

For rheumatic fever diagnosis: ``` J - joints, polyarthritis O - heart, carditis N - nodules (subcutaneous) E - erythema marginatum (pink rings on the trunk) S - Sydenham's chorea ```

Answer 54

Pharyngitis (can progress to rheumatic "PH"ever and glomerulonePHritis, cellulitis, impetigo

Answer 55

Scarlet fever, toxic shock-like syndrome, necrotizing fasciitis

Answer 56

Rheumatic fever, acute glomerulonephritis

Answer 57

Scarlet rash with sandpaper texture that spares face, strawberry tongue, scarlet throat Caused by toxigenic Streptococus pyogenes (GAS)

Answer 58

Toxin: diphtheria toxin Mechanism: inactivate elongation factor (EF-2) Manifestation: pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck)

Answer 59

Toxin: exotoxin A Mechanism: inactivate elongation factor (EF-2) Manifestation: host cells death

Answer 60

Toxin: shiga toxin (ST) Mechanism: inactivate 60S ribosome by removing adenine from rRNA Manifestation: GI mucosal damage -> dystenery, enhanced cytokine release causing HUS (hemolytic-uremic syndrome)

Answer 61

Toxin: shiga-like toxin (SLT) Mechanism: inactivate 60S ribosome by removing adenine from rRNA Manifestation: cytokine release causes HUS (hemolytic-uremic syndrome), does NOT invade cells so no GI mucosal damage

Answer 62

Toxin: heat-labile toxin (LT) and heat-stable toxin (ST) Mechanism: LT: activates adenylate cyclase (cAMP), increased Cl and H2O secretion into gut. ST: activates guanylate cyclase (cGMP), decreased reabsorption of NaCl and H2O in the gut. Manifestation: watery diarrhea "Labile in the Air" (cAMP) and "Stable on the Ground" (cGMP)

Answer 63

Toxin: edema factor Mechanism: mimics adenylate cyclase to increase cAMP Manifestation: characteristic edematous borders of black eschar in cutaneous anthrax

Answer 64

Toxin: cholera toxin Mechanism: overactivates adenylate cyclase by activating Gs, increases cAMP, increased Cl and H2O secretion into gut Manifestation: voluminous "rice-water" diarrhea

Answer 65

Toxin: pertussis toxin Mechanism: overactivates adenylate cyclase, increases cAMP by disabling Gi, impairs phagocytosis to permit survival of microbe Manifestation: whooping cough - coughs on expiration and whoops on inspiration (100 day cough in adults)

Answer 66

Toxin: tetanospasmin Mechanism: cleaves synaptobrevin (SNARE protein) Manifestation: muscle rigidity and lockjaw, prevents release of inhibitory GABA neurotransmitters

Answer 67

Toxin: botulinum toxin (BOTOX) Mechanism: cleaves SNAP-25 (SNARE protein) Manifestation: flaccid paralysis and floppy baby, prevents release of stimulatory ACh neurotransmitters

Answer 68

Toxin: alpha toxin Mechanism: phospholipase that degrades tissue and cell membranes Manifestation: degradation of phospholipase C -> myonecrosis (gas gangrene) and hemolysis ("double zone" on blood agar)

Answer 69

Toxin: steptolysin O Mechanism: protein that degrades cell membrane Manifestation: lysing of RBCs, contributes to beta-hemolysis, antibodies against the toxin are used to diagnose bacteria

Answer 70

Toxin: toxic shock syndrome toxin (TSST-1) Mechanism: brings MHC II and TCR in proximity to outside of antigen binding site, causes overwhelming release of IFNy and IL-2 -> shock Manifestation: toxic shock syndrome: fever, rash, shock, scalded skin syndrome (exfoliative toxin), food poisoning (enterotoxin)

Answer 71

Toxin: exotoxin A Mechanism: brings MHC II and TCR in proximity to outside of antigen binding site, causes overwhelming release of IFNy and IL-2 -> shock Manifestation: toxic shock syndrome: fever, rash, shock

Answer 72

Lancet-shaped, gram-positive diplococci, encapsulated, IgA protease, rusty sputum, Most common cause of: Meningitis, Otitis media, Pneumonia, Sinusitis (MOPS), sepsis in sickle cell anemia MOPS are Most OPtochin Sensitive

Answer 73

Metabolic activity without division

Answer 74

Rapid cell division Penicillins and cephalosporins act here as peptidoglycan in cell walls is being made

Answer 75

Nutrient depletion slows growth, spore formation in some bacteria

Answer 76

Prolonged nutrient depletion and buildup of waste products leads to death

Answer 77

Edema, nitric oxide, DIC/death (disseminated intravascular coagulation), Outer membrane, TNFa, O-antigen, eXtremely heat stable, IL-1 and IL-6, Neutrophil chemotaxis ENDOTOXIN

Answer 78

Form green ring around colonies on blood agar Streptococcus pneumoniae (catalse negative and optochin sensitive), Viridans streptococci (catalase negative and optochin resistant)

Answer 79

Form clear are of hemolysis on blood agar Staph. aureus (catalase and coagular positive) Strep. pyogenes (GAS, catalase negative and bacitracin sensitive) Strep. agalactiae (GBS, catalase negative and bacitracin resistant) Listeria monocytogenes (tumbling motility, meningitis in newborns, unpasteurized milk)

Answer 80

NOvobiocin - Saprophyticus is Resistant, Epidermidis is Sensitive On the office's staph retreat, there was NO StRESs

Answer 81

Optochin - Viridans is Resistant, Pneumoniae is Sensitive OVRPS Bacitracin - GBS are Resitant, GAS are Sensitive B-BRAS

Answer 82

Gram-positive cocci in grapelike clusters, protein A binds Fc-IgG, inhibiting complement fixation and phagocytosis Inflammatory disease: skin, organ absess, pneumonia, toxin-mediated: TSS, scalded skin syndrome (exfoliative toxin), food poisoning (enterotoxin - transmission due to ingestion of toxin: short incubation period and heat stable means it's not destroyed by cooking), MRSA: methicillin-resistant (nosocomial and community-acquired infections, has penicillin-binding protein) TSST: super antigen that binds to MHC II and T-cell receptor, resulting in polyclonal T-cell activation. Presents as fever, vomiting, rash, desquamation, shock, and end end-organ failure. Use of vaginal or nasal tampons predisposes you

Answer 83

Ingestion of preformed toxin

Answer 84

Infects prosthetic devices and IV catheters leading to biofilms Normal skin flora, contaminates blood cultures

Answer 85

Alpha-hemolytic Normal oropharynx flora, cause dental caries and suabcute bacterial endocarditis at damaged valves Resistant to optochin Live in the mouth because they are not afraid of-the-chin (optochin)

Answer 86

Gram-positive rods with metachromatic (blue and red) granules and Elek's test for toxin, pseudomembranous pharyngitis (gray-white membrane) with lymphadenopathy, myocarditis, and arrhythmias Black colonies on tellurite agar, or Loffler medium Causes diphtheria via exotoxin encoded by beta-prophage (inhibits protein synthesis by ADP-ribosylation of EF-2 Toxoid vaccine prevents diphtheria Coryne = club shaped ABCDEFG: ADP-ribosylation, Beta-prophage, Corynebacterium, Diphtheria, Elongation Factor 2, Granules

Answer 87

Gram-positive bacteria found in soil: Bacillus anthracis, Clostridia genus Other spore-formers: Bacillus cereus, Clostridium botulinum, Coxiella burnetii

Answer 88

Produces tetanospasmin (causes tetanus), which cleaves synaptobrevin (SNARE protein) Paralysis: blocks glycine and GABA release (inhibitory neurotransmitters) from Renshaw cells in spinal cord. Causes spastic paralysis, trismus (lockjaw), and risus sardonicus (sustained spasm of the face that looks like grinning)

Answer 89

Produces a preformed, heat-labile toxin that cleaves SNAP-25 (SNARE protein) and inhibits ACh release at the neuromuscular junction In adults, disease is caused by ingestion of preformed toxin. In babies, ingestion of spores in honey causes disease (floppy baby syndrome) Botulinum is from Bad Bottles of food and honey (causes a flaccid paralysis)

Answer 90

Toxin A: enterotoxin, binds to brush border in gut Toxin B: cytotoxin, destroys enterocyte cytoskeletal structure, causing pseudomembranous colitis Often 2° to antibiotic use, especially clindamycin or ampicillin. Diagnosed by detection of one or both toxins in stool. Difficile causes Diarrhea Treatment: metronidazole or oral vancomycin, fecal transplant

Answer 91

Produces alpha toxin (“lecithinase,” a phospholipase) that causes myonecrosis (gas gangrene) and hemolysis Perfringens perforates a gangrenous leg

Answer 92

Caused by Bacillus anthraces: gram-positive, spore-forming rod that produces anthrax toxin, only bacterium with a polypeptide capsule (contains D-glutamate)

Answer 93

Contact -> black eschar (painless ulcer) Can progress to bacteremia and death Black skin lesions: black eschar (necrosis) surrounded by edematous ring. Caused by lethal factor and edema factor

Answer 94

Inhalation of spores -> flu-like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis, and shock Woolsorters’ disease: inhalation of spores from contaminated wool

Answer 95

Gram-positive, produces spores that can survive cooking rice Keeping rice warm results in germination of spores and enterotoxin formation. Emetic type usually seen with rice and pasta Food poisoning: nnausea and vomiting within 1–5 hours: caused by cereulide, a preformed toxin. Diarrheal type causes watery, nonbloody diarrhea and GI pain in 8–18 hours "Reheated rice syndrome"

Answer 96

Facultative intracellular microbe Acquired by ingestion of unpasteurized milk/cheese and deli meats or by vaginal transmission during birth Form “actin rockets” by which they move from cell to cell. Characteristic tumbling motility Can cause amnionitis, septicemia, and spontaneous abortion in pregnant women, granulomatosis infantiseptica, neonatal meningitis, meningitis in immunocompromised patients, mild gastroenteritis in healthy individuals Treatment: gastroenteritis usually self-limited, ampicillin in infants, immunocompromised patients, and the elderly in empirical treatment of meningitis

Answer 97

Actinomyces: gram-positive anaerobe Nocardia: gram-positive aerobe

Answer 98

Actinomyces: gram-positive anaerobe Nocardia: gram-positive aerobe

Answer 99

Actinomyces: normal oral flora Nocardia: soil

Answer 100

Actinomyces: oral/facial abscesses that drain through sinus tracts, forms yellow "sulfur granules" Nocardia: pulmonary infections in immunocompromised patients and cutaneous infections after trauma in immunocompetent patients

Answer 101

Actinomyces: penicillin Nocardia: sulfonamides

Answer 102

All are acid-fast organisms Mycobacterium tuberculosis (TB, often resistant to multiple drugs), M. kansasii (pulmonary TB-like symptoms, M. avium–intracellulare (causes disseminated, non-TB disease in AIDS - often resistant to multiple drugs) TB symptoms include fever, night sweats, weight loss, and hemoptysis Cord factor in virulent strains inhibits macrophage maturation and induces release of TNF-α Prophylactic treatment with azithromycin, sulfatides (surface glycolipids) inhibit phagolysosomal fusion

Answer 103

TB PPD+ if current infection, past exposure, or BCG vaccinated PPD– if no infection or anergic (steroids, malnutrition, immunocompromise) and in sarcoidosis

Answer 104

Hilar nodes and ghon focus (mid field): small area of granulomatous inflammation that can be visualized if it calcifies

Answer 105

Fibrocaseous cavitary lesion (upper lobes) Fever, night sweats, weight loss, and hemoptysis

Answer 106

Disseminated disease characterized by tiny lesions (millet seeds)

Answer 107

1) Heals by fibrosis -> immunity and hypersensitivity -> Tuberculin positive 2) Progressive lung disease (HIV, malnutrition) and death 3) Severe bacteremia -> miliary TB and death 4) Preallergic lymphatic of hematogenous dissemination -> dormant tubercle bacilli in several organs -> reactivation later in life

Answer 108

CNS (parenchymal tuburculoma or meningitis), vertebral body (Pott's disease), lympadenitis, renal, GI

Answer 109

Caused by Mycobacterium leprae: acid-fast bacillus that likes cool temperatures (infects skin and superficial nerves—“glove and stocking” loss of sensation) Cannot be grown in vitro Reservoir in United States: armadillos Treatment: dapsone, rifampin, and clofazimine for 2–5 years for Lepromatous form, multidrug therapy consisting of dapsone and rifampin for 6 months for tuberculoid form

Answer 110

Presents diffusely over skin and is communicable Characterized by low cell-mediated immunity with a humoral Th2 response

Answer 111

Limited to a few hypoesthetic, hairless skin plaques Characterized by high cell-mediated immunity with a largely Th1- type immune response

Answer 112

Gram-negative, very mucoid colonies caused by abundant polysaccharide capsule. Red “currant jelly” sputum Intestinal flora, causes lobar pneumonia in alcoholics and diabetics when aspirated. Also cause of nosocomial UTIs. 4 A's: Aspiration pneumonia, Abscess in lungs and liver, Alcoholics, di-A-betics

Answer 113

Salmonella: have flagella (salmon swim) Shigella: no flagella

Answer 114

Salmonella: hematogenous Shigella: cell to cell spread

Answer 115

Salmonella: many animals Shigella: only humans and primates

Answer 116

Salmonella: yes Shigella: no

Answer 117

Salmonella: prolong symptoms Shigella: prolong excretion in feces

Answer 118

Salmonella: invades intestinal mucosa and causes a monocytic response Shigella: invades intestinal mucosa and causes PMN infiltration

Answer 119

Salmonella: sometimes causes bloody diarrhea Shigella: usually causes bloody diarrhea

Answer 120

Salmonella: no Shigella: no

Answer 121

Gram-negative Causes typhoid fever Found only in humans Characterized by rose spots on the abdomen, fever, headache, and diarrhea Can remain in gallbladder and cause a carrier state

Answer 122

Gram-negative, xomma or S-shaped, oxidase positive, grows at 42°C (“Campylobacter likes the hot campfire”) Fecal-oral transmission through foods such as undercooked meat (poultry, meat}, unpasteurized milk Major cause of bloody diarrhea, especially in children Common antecedent to Guillain-Barré syndrome and reactive arthritis

Answer 123

Comma shaped, oxidase positive, grows in alkaline media Produces profuse rice-water diarrhea via toxin that permanently activates Gs -> more cAMP Endemic to developing countries Treatment: prompt oral rehydration is necessary

Answer 124

Usually transmitted from pet feces (e.g., puppies), contaminated milk, or pork Causes mesenteric adenitis that can mimic Crohn’s or appendicitis

Answer 125

Gram negative

Answer 126

Gram negative

Answer 127

E. coli virulence factors: Fimbriae - cystitis and pyelonephritis K capsule - pneumonia, neonatal meningitis LPS endotoxin - septic shock.

Answer 128

Microbe invades intestinal mucosa and causes necrosis and inflammation. No toxins produced. Clinical manifestations similar to Shigella Invasive, dysentery

Answer 129

Labile toxin/stable toxin. No inflammation or invasion Traveler’s diarrhea (watery)

Answer 130

No toxin produced. Adheres to apical surface, flattens villi, prevents absorption Diarrhea usually in children (Pediatrics)

Answer 131

O157:H7 is the most common serotype. Produces Shiga-like toxin and Hemolytic-uremic syndrome (triad of anemia, thrombocytopenia, and acute renal failure) Endothelium swells and narrows lumen, leading to mechanical hemolysis and reduced renal blood flow; damaged endothelium consumes platelets Dysentery (toxin alone causes necrosis and inflammation) Does not ferment sorbitol (distinguishes it from other E. coli)

Answer 132

Obligate aerobic gram-negative rod, mon–lactose fermenting, oxidase positive, produces pyocyanin (blue-green) pigment, has a grape-like odor PSEUDOmonas is associated with wound and burn infections, Pneumonia (especially in cystic fibrosis), Sepsis (black lesions on skin), External otitis (swimmer’s ear), UTI, Drug use and Diabetic Osteomyelitis, and hot tub folliculitis Malignant otitis externa in diabetics Found in water sources Produces endotoxin (fever, shock) and exotoxin A (inactivates EF-2) Treatment: aminoglycoside plus extended- spectrum penicillin (e.g., piperacillin, ticarcillin) Aeruginosa—aerobic. Think water connection and blue-green pigment Think Pseudomonas in burn victims. Chronic pneumonia in CF patients is associated with biofilm

Answer 133

Gram-negative rod. Gram stains poorly—use silver stain. Grow on charcoal yeast extract culture with iron and cysteine Legionnaires’ disease = severe pneumonia, fever, GI and CNS symptoms Pontiac fever = mild flu-like syndrome Detected clinically by presence of antigen in urine Aerosol transmission from environmental water source habitat. No person-to-person transmission Treatment: macrolide or quinolone. Think of a French legionnaire (soldier) with his silver helmet, sitting around a campfire (charcoal) with his iron dagger—he is no sissy (cysteine). Labs show hyponatremia.

Answer 134

Grow pink colonies on MacConkey’s agar Examples: Citrobacter, Klebsiella, E. coli, Enterobacter, and Serratia E. coli produces β-galactosidase, which breaks down lactose into glucose and galactose Lactose is KEE Test with MacConKEE’S agar EMB agar—lactose fermenters grow as purple/black colonies, E. coli grows purple colonies with a green sheen

Answer 135

Gram-negative bacilli are resistant to penicillin G but may be susceptible to penicillin derivatives such as ampicillin and amoxicillin The gram-negative outer membrane layer inhibits entry of penicillin G and vancomycin

Answer 136

Gram-negative diplococci Both ferment glucose and produce IgA proteases MeninGococci ferment Maltose and Glucose, Gonococci ferment Glucose

Answer 137

Small gram-negative (coccobacillary) rod, produces IgA protease Aerosol transmission HaEMOPhilus causes Epiglottitis (“cherry red” in children), Meningitis, Otitis media, and Pneumonia Most invasive disease caused by capsular type B. Nontypeable strains cause mucosal infections (otitis media, conjunctivitis, bronchitis) Culture on chocolate agar requires factors V (NAD+) and X (hematin) for growth, can also be grown with S. aureus, which provides factor V (mnemonic: When a child has “flu,” mom goes to five (V) and dime (X) store to buy some chocolate) Treat meningitis with ceftriaxone. Rifampin prophylaxis in close contacts Vaccine contains type B capsular polysaccharide (polyribosylribitol phosphate) conjugated to diphtheria toxoid or other protein. Given between 2 and 18 months of age Does not cause the flu (influenza virus does)

Answer 138

Neisseria gonococci: no capsule Neisseria meningococci: polysaccharide capsule

Answer 139

Neisseria gonococci: no Neisseria meningococci: yes (Meningococci Maltose)

Answer 140

Neisseria gonococci: no vaccine Neisseria meningococci: yes, except for type B

Answer 141

Neisseria gonococci: sexual transmission Neisseria meningococci: respiratory and oral secretions

Answer 142

Neisseria gonococci: gonorrhea, septic arthritis, neonatal conjunctivitis, PID (pelvic inflammatory disease), Fitz-Hugh-Curtis syndrome (PID complication: acute onset RUQ abdominal pain aggravated by breathing, coughing or movement, which is referred to the right shoulder Neisseria meningococci: meningococcemia and meningitis, Waterhouse-Friderichsen syndrome (severe septicemia with fever, rigors, vomiting and headache)

Answer 143

Neisseria gonococci: ceftriaxone + azithromycin or doxycycline for possible chlamdydia coinfection Neisseria meningococci: certriaxone of penicillin G, rifampin, ciprofloxacin, or ceftriaxone prophylaxis in close contacts

Answer 144

Gram-positive, spore forming, obligate anaerobes

Answer 145

Causes gastritis and 90% of duodenal ulcers, risk factor for peptic ulcer, gastric adenocarcinoma, and lymphoma Curved gram-negative rod, urease positive (urea breath test), creates an alkaline environment for itself Treatment: triple therapy - PPI (-prazoles), clarithromycin (macrolide), amoxicillin or metronidazole

Answer 146

Spiral-shaped bacteria with axial filaments Borrelia (big size), Leptospira, and Treponema Borrelia can be visualized with aniline dyes (Wright's or Giemsa stain) in light microscopy, Treponema is visualized by dark-field microscopy and fluorescent-antibody staining

Answer 147

Gram-negative spirochete Found in water contaminated with animal urine, common among surfers and in the tropic (Hawaii) Weil's disease (icterohemorrhagic leptospirosis): severe form with jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, anemia

Answer 148

Borrelia burgdorferi, which is transmitted by the deer tick Ixodes (also carries babesia), natural reservoir is the mouse. Gram-negative spirochete Northeastern US 1) erythema chronicum migrans (expanding bull's eye red rash with central clearing), flu-like symptoms, 2) neurologic (facial nerve palsy) and cardiac (AV nodal block) manifestations, 3) musculoskeletal (chronic monoarthritis and migratory polyarthritis), neurological (encephalopathy and polyneuropathy), and cutaneous manifestations FAKE a key LYME pie: Facial nerve (bilateral), Arthritis, Kardiac block, Erythema migrans

Answer 149

Gram-negative spirochete Treponema pallidum Treatment: penicillin G

Answer 150

Localized disease presenting with painless chanche (ulceration) Screen with VDRL (serum test) and confirm diagnosis with FTA-ABS (blood with fluorescent antibody and dark-field microscopy) Treponemes are present in chancres of primary and condylomata lat a of secondary, may be directly visualized with dark-field

Answer 151

Disseminated disease with constitutional symptoms, maculopapular rash (palms and soles), condylomata lata (wart-like lesions on genitals) Treponemes are present in chancres of primary and condylomata lat a of secondary, may be directly visualized with dark-field Screen with VDRL, confirm with FTA-ABS Secondary = Systemic

Answer 152

Gummas (chronic granulomas), aoritisis (vasa vasorum destruction), neurosyphilis (tabes dorsalis), Argyll Robertson pupil Broad-based ataxia, positive Romberg, Charcot joint, stroke without HTN Test with spinal fluid VDRL

Answer 153

Saber shins (malformation of tibia, sharp bowing), saddle nose, CN VIII deafness, Hutchinson's teeth (smaller, widely-spaced, notches on biting surfaces), mulberry molars (small, lots of enamel ridges on the top of the 1st molars) Early prevention is key, as placental transmission typically occurs after the first trimester

Answer 154

Constricts with accommodation but is not reactive to light Associated with tertiary syphilis "Prostitute's pupil:" accommodates but does not react

Answer 155

VDRL detects nonspecific antibody that reacts with beef cardiolipin. Used for diagnosis of syphilis, but many false positives, including viral infection (mononucleosis, hepatitis), some drugs, rheumatic fever, SLE, and leprosy VDRL: Viruses (mono, hepatitis), Drugs, Rheumatic fever, Lupus/Leprosy

Answer 156

Flu-like syndrome immediately after antibiotics are started Due to killed bacteria releasing pyrogens.

Answer 157

Infections transmitted from animals to human

Answer 158

Disease: cat scratch disease (lympadenopathy, fever, chills, headache, back pain), bacillary angiomatosis (tumor-like growths of blood vessels) Transmission: cat scratch

Answer 159

Disease: Lyme disease (FAKE a key LYME pie: Facial nerve (bilateral), Arthritis, Kardiac block, Erythema migrans) Transmission: Ixodes (deer and mice ticks)

Answer 160

Disease: relapsing fever (recurrent due to variable surface antigens) Transmission: louse

Answer 161

Disease: Brucellosis/undulant fever Transmission: unpasteurized dairy

Answer 162

Disease: bloody diarrhea Transmission: puppies, livestock (fecal-oral, ingestion of undercooked meat, especially chicken)

Answer 163

Disease: Psittacosis Transmission: parrots and other birds

Answer 164

Disease: Q fever (flu-like symptoms with abrupt onset of fever and headache) Transmission: aerosols of cattle/sheep amniotic fluid (farmers, vets)

Answer 165

Disease: tularemia Transmission: ticks, rabbits, deer fly

Answer 166

Disease: ehrlichiosis Transmission: Lone Star ticks

Answer 167

Disease: leptospirosis Transmission: animal urine

Answer 168

Disease: leprosy Transmission: humans with lepromatous leprosy, armadillo (rare)

Answer 169

Disease: cellulitis, osteomyelitis Transmission: animal bite, cats, dogs

Answer 170

Disease: endemic typhus Transmission: louse

Answer 171

Disease: Rocky Mountain Spotted Fever Transmission: Dermacentor ticks

Answer 172

Disease: endemic typhus Transmission: fleas

Answer 173

Disease: Plague Transmission: fleas (rats and prairie dogs are reservoirs)

Answer 174

Disease: anaplasmosis Transmission: Ixodes ticks (deer and mice)

Answer 175

Pleomorphic, gram-variable rod Causes vaginosis presenting as a gray vaginal discharge with a fishy smell, nonpainful. Associated with sexual activity, but not an STD Bacterial vaginosis is characterized by overgrowth of certain bacteria in vagina. Clue cells, or vaginal epithelial cells covered with bacteria, are visible under the microscope Treatment: metronidazole I don't have a CLUE why I smell FISH in the VAGINA GARDEN

Answer 176

Rickettsiae are obligate intracellular organisms that need CoA and NAD+. Doxycycline for all

Answer 177

Rocky Mountain spotted fever (tick): Rickettsia rickettsii. Broadly distributed in US (in spite of name). Rash typically starts at wrists and ankles Typhus: Endemic (fleas): R. typhi. Epidemic (human body louse): R. prowazekii. Rash starts centrally and spreads out, sparing palms and soles Classic triad—headache, fever, rash (vasculitis) “Rickettsii on the wRists, Typhus on the Trunk” Palm and sole rash is seen in Coxsackievirus A infection (hand, foot, and mouth disease), Rocky Mountain spotted fever, and secondary Syphilis (you drive CARS using your palms and soles)

Answer 178

Ehrlichiosis (tick): Ehrlichia. Monocytes with morula (berry-like inclusions) in cytoplasm Anaplasmosis (tick): Anaplasma. Granulocytes with morula in cytoplasm ``` Q fever (tick feces and cattle placenta release spores that are inhaled as aerosols): Coxiella burnetii. No arthropod vector. Presents as pneumonia ``` Q fever is Queer because it has no rash or vector and its causative organism can survive outside in its endospore form. Not in the Rickettsia genus, but closely related

Answer 179

No cell wall. Not seen on Gram stain. Bacterial membrane contains sterols for stability. High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs Grown on Eaton’s agar Classic cause of atypical “walking” pneumonia (insidious onset, headache, nonproductive cough, diffuse interstitial infiltrate) X-ray looks worse than patient. Treatment: macrolide or fluoroquinolone (penicillin ineffective since Mycoplasma have no cell wall) Mycoplasmal pneumonia is more common in patients < 30 years of age Frequent outbreaks in military recruits and prisons

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Chronic infection, causes blindness due to follicular conjunctivitis in Africa ABC: Africa/Blindness/Chronic infection

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Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), or neonatal conjunctivitis D-K = everything else Neonatal disease can be acquired during passage through infected birth canal

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Lymphogranuloma venereum

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Chlamydiae cannot make their own ATP. They are obligate intracellular organisms that cause mucosal infections. Cell wall is unusual in that it lacks muramic acid 2 forms: Elementary body (small, dense) is “Enfectious” and Enters cell via Endocytosis. Reticulate body Replicates in cell by fission; form seen on tissue culture Lab diagnosis: cytoplasmic inclusions seen on Giemsa or fluorescent antibody–stained smear Chlamydia trachomatis causes reactive arthritis, conjunctivitis, nongonococcal urethritis, and PID C. pneumoniae and C. psittaci cause atypical pneumonia; transmitted by aerosol Treatment: azithromycin (favored because one- time treatment) or doxycycline Chlamys = cloak (intracellular). Chlamydophila psittaci is notable for an avian reservoir

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Cause pneumonia and can disseminate All are caused by dimorphic fungi: cold (20°C) = mold, heat (37°C) = yeast. Exception is coccidioidomycosis, which is a spherule (not yeast) in tissue Treatment: fluconazole or itraconazole for local infection; amphotericin B for systemic infection Systemic mycoses can mimic TB (granuloma formation), except, unlike TB, have no person-person transmission

Answer 185

Mississippi and Ohio River valleys, bird or bat droppings Pneumonia Macrophage filled with Histoplasma (smaller than RBC) Histo Hides within macrophages

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States east of the Mississippi River and in Central America Causes inflammatory lung disease, can disseminate to skin and bone Granulomatous nodules, broad-based budding (same size as RBC) Blasto Buds Broadly

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Southwestern states, California. Increases after earthquakes, because spores in the dust are thrown up into the air and become spherules in the lungs Pneumonia and menigitis, can disseminate to bone and skin Spherule filled with endospores (much larger than RBC) Coccidio crowds San Joaquin Valley: "valley fever"

Answer 188

Latin America Budding yeast with "captain's wheel" formation (much larger than RBC) Paracoccidio parasails with the captain's wheel all the way to Latin America

Answer 189

Tinea pedis (foot), tinea cruris (groin), tinea corporis (ringworm, on body), tinea capitis (head, scalp), tinea unguium (onchyomycosis, on fingernails) Pruritic lesions with central clearing resembling a ring, caused by dermatophytes (Microsporum, Trichophyton, Epidermophyton) Mold hyphae in KOH prep, not dimorphic

Answer 190

Caused by Malassezia furfur Degradation of lipids produces acids that damage melanocytes and cause hypopigmented and/or hyper pigmented patches Treatment: topical miconazole, selenium sulfide (Selsun) “Spaghetti and meatball” appearance on KOH prep A . Occurs in hot, humid weather.

Answer 191

Systemic or superficial fungal infection Oral and esophageal thrush in immunocompromised (neonates, steroids, diabetes, AIDS), vulvovaginitis (diabetes, use of antibiotics), diaper rash, endocarditis in IV drug users, disseminated candidiasis (to any organ), chronic mucocutaneous candidiasis Treatment: topical azole for vaginal; fluconazole or caspofungin for oral/esophageal; fluconazole, amphotericin B, or caspofungin for systemic alba = white

Answer 192

Invasive aspergillosis, especially in immunocompromised and those with chronic granulomatous disease Allergic bronchopulmonary aspergillosis (ABPA): with asthma or CF, aspergillomas in lung cavities, especially after TB infection Some species of Aspergillus produce aflatoxins, which are associated with HCC Think “A” for Acute Angles in Aspergillus. Not dimorphic

Answer 193

Cryptococcal meningitis, cryptococcosis Heavily encapsulated yeast. Not dimorphic. Found in soil, pigeon droppings Acquired through inhalation with hematogenous dissemination to meninges Culture on Sabouraud’s agar. Stains with India ink Latex agglutination test detects polysaccharide capsular antigen and is more specific. “Soap bubble” lesions in brain

Answer 194

Mucormycosis Disease mostly in ketoacidotic diabetic and leukemic patients Fungi proliferate in blood vessel walls when there is excess ketone and glucose, penetrate cribriform plate, and enter brain Rhinocerebral, frontal lobe abscesses. Headache, facial pain, black necrotic eschar on face; may have cranial nerve involvement

Answer 195

Causes Pneumocystis pneumonia (PCP), a diffuse interstitial pneumonia Yeast (originally classified as protozoan). Inhaled. Most infections are asymptomatic Immunosuppression (e.g., AIDS) predisposes to disease. Diagnosed by lung biopsy or lavage. Disc-shaped yeast forms on methenamine silver stain of lung tissue A. Diffuse, bilateral CXR appearance Treatment: TMP-SMX (sulfonamide), pentamidine, dapsone. Start prophylaxis when CD4 drops < 200 cells/mm3 in HIV patients

Answer 196

Sporotrichosis. Dimorphic, cigar-shaped budding yeast that lives on vegetation A When spores are traumatically introduced into the skin, typically by a thorn (“rose gardener’s” disease) Causes local pustule or ulcer with nodules along draining lymphatics (ascending lymphangitis). Little systemic illness Treatment: itraconazole or POTassium iodide (“plant a rose in the POT")

Answer 197

GI protozoa Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers). Think FAT-rich Ghirardelli chocolates for fatty stools of Giardia Cysts in water Trophozoites or cysts in stool Metronidazole

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GI protozoa Amebiasis: bloody diarrhea (dysentery), liver abscess (“anchovy paste” exudate), RUQ pain (histology shows flask-shaped ulcer if submucosal abscess of colon ruptures) Cysts in water Serology and/or trophozoites (with RBCs in the cytoplasm) or cysts (with multiple nuclei) in stool Metronidazole, iodoquional (Fe chelator) for non-symptomatic cyst passers

Answer 199

GI protozoa Severe diarrhea in AIDS. Mild disease (watery diarrhea) in non-immunocompromised Cysts in water Cysts on acid-fast stain Prevention (by filtering city water supplies), nitazoxanide in immunocompetent hosts

Answer 200

CNS protozoa Brain abscess in HIV (seen as ring-enhancing brain lesions on CT/MRI). Congenital toxoplasmosis = “classic triad” of chorioretinitis, hydrocephalus, and intracranial calcifications Cysts in meat or cat feces, can cross placenta (pregnant women should avoid cats) Serology, biopsy Sulfadiazine + pyrimethamine

Answer 201

CNS protozoa Rapidly fatal meningitis Swimming in freshwater lakes (think Nalgene bottle filled with freshwater containing Naegleria), enters via cribriform plate Amoebas in spinal fluid Amphotericin has been effective for some survivors

Answer 202

CNS protozoa African sleeping sickness: enlarged lymph nodes, recurring fever (due to antigenic variation), somnolence, coma Tsetse fly (painful bite) Blood smear Suramin for blood-borne disease or melarsoprol for CNS penetration (“it SURe is nice to go to sleep, MELatonin helps with sleep)

Answer 203

Hematologic protozoa Malaria: fever, headache, anemia, splenomegaly P. vivax/ovale: 48-hr cycle (tertian, includes fever on first day and third day, thus fevers are actually 48 hr apart) or dormant form (hypnozoite) in liver P. falciparum: severe; irregular fever patterns, parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys, lungs P. malariae—72-hr cycle (quartan) Mosquito (Anopheles) Blood smear, trophozoite ring form A , RBC schizont with merozoites B Begin with chloroquine, which blocks Plasmodium heme polymerase. If resistant, use mefloquine. If life-threatening, use intravenous quinidine (test for G6PD deficiency or serious methemoglobinemia may occur). Vivax/ovale—add primaquine for hypnozoite (test for G6PD deficiency)

Answer 204

Hematologic protozoa Babesiosis: fever and hemolytic anemia, predominantly in northeastern United States, asplenia: risk of severe disease Ixodes tick (same as Borrelia burgdorferi of Lyme disease, may often coinfect humans) Blood smear, ring form, “Maltese cross” C2, PCR Atovaquone + azithromycin

Answer 205

Visceral protozoa Chagas’ disease: dilated cardiomyopathy, megacolon, megaesophagus. Predominantly in South America Reduviid bug (“kissing bug”), a painless bite (much like a kiss) Blood smear Nifurtimox

Answer 206

Visceral protozoa Sandfly Visceral leishmaniasis (kala-azar): spiking fevers, hepatosplenomegaly, pancytopenia Macrophages containing amistigotes Sodium stibogluconate

Answer 207

STD protozoa Vaginitis: foul-smelling, greenish discharge; itching and burning; do not confuse with Gardnerella vaginalis, a gram-variable bacterium that causes vaginosis Sexual transmission Mobile trophozoites on wet mount Metronidazole for patient and partner (prophylaxis)

Answer 208

Protein shell immediately surrounding nuclei acid

Answer 209

Derived from plasma membranes, cover capsids Sensitive to desiccation, heat, and detergents

Answer 210

Exchange of genes between 2 chromosomes with significant base homology

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When viruses with segmented genomes (influenza is an example) exchange segments. High-frequeny recombination. Ultimately responsible for flu pandemics

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Occurs when 1 of 2 viruses infecting a cell has a mutation resulting in a nonfunctional protein. The nonmutated virus “complements” the mutated one by making a functional protein that can be used by both viruses

Answer 213

Occurs with co-infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated with the surface proteins of virus B (this is a pseudovirion) Type B protein coat determines the tropism (which cells can be infected) of the hybrid virus, but the progeny from this infection will get a type A coat again because those genes will be translated

Answer 214

All DNA viruses except Parvoviridae are dsDNA All are linear except papilloma-, polyoma-, and hepadnaviruses (circular) All are dsDNA except “part-of-a- virus” (parvovirus) is ssDNA Parvus = small

Answer 215

Induce humoral and cell-mediated immunity but have reverted to virulence on rare occasions Killed/inactivated vaccines induce only humoral immunity but are stable Live attenuated—smallpox, yellow fever, chickenpox (VZV), Sabin’s polio virus, MMR, Influenza (intranasal) No booster needed for live attenuated vaccines. Dangerous to give live vaccines to immunocompromised patients or their close contacts “LIVE! One night only! See SMALL YELLOW CHICKENS get vaccinated with SABIN'S and MMR! It’s INcredible!” MMR = measles, mumps, rubella (live attenuated vaccine that can be given to HIV- positive patients who do not show signs of immunodeficiency).

Answer 216

Rabies, Influenza (injected), Salk Polio, and HAV vaccines SalK = Killed. RIP Always

Answer 217

HBV (antigen = recombinant HBsAg), HPV (types 6, 11, 16, and 18)

Answer 218

All RNA viruses except Reoviridae are ssRNA Positive-stranded RNA viruses: I went to a retro (retrovirus) toga (togavirus) party, where I drank flavored (flavivirus) Corona (coronavirus) and ate hippy (hepevirus) California (calicivirus) pickles (picornavirus). All are ssRNA except “repeato-virus” (reovirus) is dsRNA

Answer 219

Purified nucleic acids of most dsDNA (except poxviruses and HBV) and (+) strand ssRNA (≈ mRNA) viruses are infectious Naked nucleic acids of (−) strand ssRNA and dsRNA viruses are not infectious. They require polymerases contained in the complete virion

Answer 220

All viruses are haploid (with 1 copy of DNA or RNA) except retroviruses, which have 2 identical ssRNA molecules (≈ diploid)

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Replicate within the nucleus. Exception: poxvirus (which carries its own DNA-dependent RNA polymerase)

Answer 222

Replicate in the cytoplasm. Exceptions: influenza and retrovirus

Answer 223

Naked (nonenveloped) viruses include Papillomavirus, Adenovirus, Picornavirus, Polyomavirus, Calcivirus, Parvovirus, Reovirus, and Hepevirus Enveloped viruses acquire their envelopes from plasma membrane when they exit from cell (exceptions include herpesviruses, which acquire envelopes from nuclear membrane) Give PAPP smears and CPR to a naked Heppy (hippy). DNA = PAPP; RNA = CPR and hepevirus

Answer 224

HHAPPPPy viruses (Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma) Are double stranded (except parvo) Are linear (except papilloma and polyoma (circular, supercoiled) and hepadna (circular, incomplete)) Are icosahedral (except pox, which is complex) Replicate in the nucleus (except pox, which carries its own DNA-dependent RNA polymerase)

Answer 225

PCR is best Tzanck test—a smear of an opened skin vesicle to detect multinucleated giant cells commonly seen in HSV-1, HSV-2, and VZV Infected cells also have intranuclear Cowdry A inclusions Tzanck God I don't have HSV

Answer 226

Herpesvirus, causes mononucleosis Infects B cells Characterized by fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (especially posterior cervical nodes). Also associated with development of Hodgkin’s and endemic Burkitt’s lymphomas as well as nasopharyngeal carcinoma. Peak incidence 15–20 years of age ("kissing years") Atypical lymphocytes seen on peripheral blood smear A are not infected B cells but rather reactive cytotoxic T cells Positive Monospot test: heterophile antibodies detected by agglutination of sheep or horse RBCs

Microbiology Flashcards

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