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1

What is positive sense RNA?

Viral RNA that can be used as mRNA

2

What is negative sense RNA?

Viral RNA that is complientary to mRNA and needs virion associated RNA-dependant RNA polymerase

3

What are the arboviruses?

Togavirus, flavivirus, bunyavirus

4

Viruses inactivated by heat, detergents and solvents

Enveloped viruses

5

Viruses that can't be inactivated by heat, detergents and solvents

Naked viruses

6

How do dsDNA viruses make mRNA?

Negative strand of genome serves a template for mRNA. No intermediate.

7

How do retroviruses make mRNA?

mRNA is transcribed from dsDNA intermediate.

8

How do +RNA viruses make mRNA?

Through a -RNA intermediate

9

How do -RNA viruses make mRNA?

RNA is template for +mRNA without intermediate

10

What are the killed vaccines?

Rabies, Influenza, Polio (Salk), A hepatitis. RIP Always""

11

What are the live vaccines?

Mumps, Rubella, Varicella-Zoster, Measles, Adenovirus, Polio (Sabin), Small Pox, Yellow Fever. Mr. V.Z. Mapsy""

12

What are the DNA virus families?

Herpes, Hepadna, Adeno, Parvo, Pox, Papova. HHAPPPy""

13

What are the naked virus families?

Calicivirus, PEeCoRnA virus, Reovirus, Parvo, Adeno, Papilloma, Polyoma. Naked CPR and PAPP smear""

14

What are the +RNA virus families?

Calici, PEeCoRnA, Flavi, Toga, Corona, Retro. Call Pico and Flava To Come Rap""

15

What are the -RNA virus families?

PaRaMyxo, Rhabdo, Arena, Filo, Orthomyxo, Bunya, Delta. Para Rabiar in the Arena, Fill or Buny""

16

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)

17

Characteristics of Herpesviruses

Enveloped, dsDNA, linear, icosahedral, replicates in nucleus, intranuclear inclusion bodies and latency

18

Characteristics of hepadnaviruses

Enveloped, dsDNA, circular, icosahedral, replicates in nucleus

19

Characteristics of adenovirus

Naked, dsDNA, linear, icosahedral, replicates in nucleus

20

Characteristics of Parvovirus

Naked, ssDNA, linear, icosahedral, replicates in nucleus

21

Characteristics of Papovavirus

Naked, dsDNA, circular, icosahedral, replicates in nucleus

22

Characteristics of Poxvirus

Enveloped, dsDNA, linear, complex, replicates in cytoplasm (DNA-dependant RNA polymerase)

23

Characteristics of Caliciviruses

Non-enveloped, +ssRNA, linear, icosahedral

24

Characteristics of PEeCoRnA viruses

Non-enveloped, +ssRNA, linear, icosahedral

25

What are the Herpes viruses?

HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-8

26

What are the PEeCoRnA viruses?

Polio, Echo, Coxsackie, Rhino, Hep A. PEeCoRnAvirus""

27

What are the Caliciviruses?

HEV, Norwalk

28

What are the Reoviruses?

Reovirus, Rotavirus

29

What are the Flaviviruses?

HCV, yellow fever, dengue, St. Louis encephalitis, West Nile virus

30

What are the Togaviruses?

Rubella, eastern equine encephalitis, western equine encephalitis

31

What are the Retroviruses?

HIV, HTLV

32

What are the Orthomyxoviruses?

Influenza

33

What are the Paramyxoviruses?

Parainfluenza, RSV, Rubeola (Measles), Mumps. PaRaMyxovirus""

34

What are the Rhabdoviruses?

Rabies

35

What are the Filoviruses?

Ebola

36

Pathogenesis of Parvovirus B19

Infects immature erythroid progenitors resulting in lysis. May cause aplastic crisis in sickle-cell anemia.

37

Pathogenesis of HSV

Infects epithelial cells with formation of vesicles. Establishes latent infection in the ganglion. Reactivation with stress.

38

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

39

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

40

Pathogenesis of CMV

Infects salivary epithelial cells and latency in mononuclear cells (Owl eye inclusions)

41

Pathogenesis of Polio virus

Destroys anterior horn motor neurons

42

Pathogenesis of Rabies virus

Binds peripheral nerves via nicotinic Ach receptor --> retrograde transport to dorsal root ganglia --> brain

43

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.

44

Diseases caused by Parvovirus B19

Erythema infectiosum (raised indurated slapped cheek" facial rash). Hydrops fetalis and spontaneous abortions."

45

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.

46

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.

47

Chickenpox

VZV. Fever, pharyngitis, asynchronous rash.

48

Shingles

VZV. Pain and vesicles restricted to one dermatome in the 5th or 6th decade. Reactivation of latent infection.

49

Heterophile+ mononucleosis

EBV. Generalized teder lymphadenopathy, splenomegaly with latency in B cells. Atypical lymphocytes and heterophile antibodies that agglutinate cow and sheep RBCs.

50

Malignancies by EBV

Burkitt's lymphoma: t(8:14) mandible or abdomen; Hodgkin lymphoma; Nasopharyngeal CA.

51

Heterophile- mononucleosis

CMV. Generalized tender lymphadenopathy, splenomegaly, Owl-eye inclusions

52

Cytomegalic inclusion disease

CMV. MC in-utero infection in US. Jaundice, hepatosplenomegaly, thrombocytic purpura, pneumonitis, CNS damage

53

CMV infections in immunocompromised

Interstitial pneumonitis, systemic infection in AIDS and transplant patients. CMV retinitis in AIDS patients.

54

Roseola

HHV-6. Fever for 3-5 days followed by a non-pruritic maculopapular rash in the trunk.

55

Kaposi sarcoma

Malignancy of epithelial cells caused by HHV-8 which has a gene that turns on VEGF. Seen in AIDS.

56

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)

57

Diseases caused by Poxviruses

Variola (prodrome followed by synchronous rash and guarnieri intracytoplasmic inclussions); Molluscum contagiosum (umbilicated warts).

58

Diseases caused by Norwalk virus

Acute gastroenteritis. Watery diarrhea, nausea, vomiting. Associated to outbreak in cruise ships.

59

Polio

Destroys anterior horn motor neurons. Flaccid paralysis without sensory loss. Live vaccine (Sabin), killed vaccine (Salk)

60

Diseases caused by Coxsackie viruses

Aseptic meningitis, herpangina, myocarditis. Associated with type I DM and dilated cardiomyopathy.

61

MCC common cold

Rhinovirus, followed by coronavirus.

62

Infectious hepatitis

HAV. Fever, malaise, headache, vomiting, coluria, jaundice.

63

Culex mosquito

SLE, WNV.

64

Aedes mosquito

Dengue, YFV

65

Dengue

Fever, myalgia, arthralgia, petechiae, thrombocytopenia, neutropenia.

66

Yellow fever

Fever, jaundice, black vomit

67

Causes of encephalitis

SLE, WNV, EEE, WEE, VEE, CMV

68

Causes of asceptic meningitis

Coxsackie

69

German measles

Rubella. Erythematous maculopapular rash from face to torso. No koplik spots.

70

SARS

SARS-CoV. Atypical pneumonia with dry cough, dyspnea, hypoxia, acute respiratory distress. Travel to Far East or Toronto.

71

AIDS gag gene

Encodes p24 capsid protein and p17 matrix protein

72

AIDS pol gene

Encodes reverse transcriptase (genetic drift of env gp), integrase (integrates DNA into genome), protease

73

AIDS env gene

Encodes gp160 which is cleaved to gp120 (binds CD4, CCR5, CXCR4) and gp41 (viral fusion)

74

AIDS tat gene

Upregulates transcription

75

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

76

Homozygous CCR5 mutation

Immune to HIV infection

77

Heterozygous CCR5 mutation

Slow course of AIDS

78

CXCR1 mutation

Rapid progression to AIDS

79

Symptomatic HIV infections

Bacillary angiomatosis, oral or vulvovaginal candidiasis, cervical dysplasia, hairy leukoplakia, ITP, listeriosis, PID, peripheral neuropathy

80

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

81

AIDS infections with <400 CD4

Oral thrush, tinea pedis, shingles, TB, bacterial infections

82

AIDS infections with <200 CD4

Cryptosporidiosis, isosporidiosis, coccidiodomycosis, pneumocystis jiroveci

83

AIDS infections with <100 CD4

Candida esophagitis, toxoplasmosis, histoplasmosis

84

AIDS infections with <50 CD4

CMV retinitis and esophagitis, disseminated M. avium, cryptococcal meningoencephalitis

85

Measles

Cough, coryza, conjunctivits, photophobia, Koplik spots, maculopapular rash from face down. Complication: SSPE

86

Mumps

Bilateral parotitis, fever, headache, swelling or parotids. Complications: pancreatitis, orchitis, infertility

87

Croup

Parainfluenza. Barking cough, inspiratory stridor, hoarseness.

88

MCC pneumonia in children 1m-18yr

Atypical pneumonia by RSV.

89

Rabies

Hydrophobia, seizures, hallucinations, coma, death. Associated with bat or dog bites. Negri bodies.

90

Influenza

Fever, chills, bronchiolitis, vomiting, croup, pneumonia. Can lead to Reye or Guillain-Barre.

91

MCC of infantile gastroenteritis

Rotavirus

92

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.

93

Viral genetics: recombination

Exchange of genes between 2 chromosomes

94

Viral genetics: reassortment

Genetic shift. Two strains of a segmented virus coinfect a cell and recombine to produce a new progeny. Responsible for pandemics.

95

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.

96

Characteristics of Malassezia furfur

Normal skin flora. Yeast clusters and short curved hyphae on KOH mount. Spaghetti and meatballs" appearance."

97

Characteristics of dermatophytes

Filamentous monomorphic fungi. KOH mount shows arthroconidia and hyphae.

98

Types of dermatophytes

Microsporum, Trichophyton, Epidermophyton

99

Characteristics of Sporothrix schenckii

Hyphae with rosettes and sleeves of conidia in the envirenment. Cigar-shaped yeast in tissue

100

Characteristics of Histoplasma capsulatum

Hyphae with microconidia and tuberculate macroconidia in environment. Small intracellular yeasts inside macrophages.

101

Characteristics of Coccidioides immitis

Hypahe breaking up into arthroconidia is environmental form. Spherules with endospores is tissue form.

102

Characteristics of Blastomyces dermatitidis

Hyphae with nondescript conidia is environmental form. Broad-based budding yeats with double refractile cell wall in tissue.

103

Characteristics of Aspergillus fumigatus

Monomorphic fungus with septate hyphae and dichotomous branches at 45 degree angles

104

Characteristics of Candida albicans

Yeast is normal flora of mucous membranes. Germ tubes in serum. Pseudohyphae and true hyphae in tissues.

105

Characteristics of Cryptococcus neoformans

Encapsulated monomorphic yeast on India ink. Capsular halo" in CSF sample."

106

Characteristics of Mucor

Nonspetate hyphae with 90 degree angle branches

107

Characteristics of Pneumocystis jirovenci

Obligate extracellular parasite shows silver-staining cysts in tissues.

108

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

109

Tinea

Scaly, itchy ring-like lessions of the skin. Can also invade scalp, body and feet. Rx.: topical imidazoles.

110

Cutaneous sporotrichosis

Subcutaneous or lymphocutaneous mycetomas seen in gardeners, florists, basket weavers. Rx.: itraconazole or amphotericin B

111

Pulmonary sporotrichosis

Pulmonary mycetomas seen in urban homeless alcoholics. Rx.: itraconazole or amphotericin B

112

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

113

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.

114

Blastomycosis

B. dermatitidis. Acute or chronic pulmonary disease. Rx.: amphotericin B/ketoconazole

115

Allergic bronchopulmonary aspergillosis

A. fumigatus. Asthma and allergies predispose as it grows in mucous plugs

116

Fungus ball

A. fumigatus. Grows in lung cavitations need to surgically remove.

117

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

118

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.

119

Cryptococcosis

C. neoformans. Meningitis in Hodgkin and AIDS patients. Acute pulmonary infection in pigeon breeders. Rx.: AMB+5 flucytosine

120

Rhinocerebral infection

Mucor. Paranasal swelling, necrotic tissues and hemorrhagic exudates in ketoacidotic diabetics and leukemic patients. Rx.: amphotericin B

121

Pneumocystis pneumonia

Atypical pneumonia in AIDS patients. Nonproductive cough, fever, dyspnea, destruction of type I pneumocytes. Patchy infiltrate in x-ray. Rx.: trimethrophrim sulfa

122

Normal flora of cutaneous surfaces

Staph epidirmidis, staph aureus, strep

123

Normal flora of the nose

Staph aureus

124

Normal flora of the oropharynx

Viridans strep, strep mutans, nonpathogenic Neisseria, nontypable H. influenzae

125

Colon normal flora

anaerobic bacteroides, gram- anaerobic rods

126

Normal flora of the vagina

Lactobacillus

127

Encapsulated bacteria

Strep pneumonia, Klebsiella, Haemophilus, Pseudomonas, Neisseria menigitidis, Cryptococcus neoformans. Some Killers Have Pretty Nice Capsules""

128

Teichoic acids

Adherence and pathogenicity factor of gram positive bacteria

129

Pili/fimbriae

Adherence and antiphagocytic component of gram negative bacteria (specially N. gonorrehae)

130

M protein

Strep pyogenes (group A ?-hemolytic) antiphagocytic surface component

131

A protein

Staph aureus virulence factor binds Fc portion if IgG and inhibits opsonization and phagocytosis

132

IgA protease

Destructs mucosal IgA. Produced by Neisseria, Haemophilus, S. Pneumoniae

133

LPS

Gram negative membrane component endotixin. Heat-stable, not immunogenic. Lipid A is toxic component.

134

MOA LPS

LPS activates macrophages with release of TNF-?, 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).

135

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-? which activates macrophages to release IL-1, TNF-alpha and IL-6 and an exagerated reaction

136

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

137

Exotoxin A

Pseudomonas. ADP ribosylation and inactivation of EF-2 inibits eukaryotic protein synthesis mainly in hepatocytes

138

Shiga toxin

Shigella. Cleaves 60S ribosomal subunit, inhibits protein synthesis

139

Verotoxin

E.coli O157. Cleaves 60S ribosomal subunit, inhibits protein synthesis. Causes HUS

140

Tetanus toxin

C. tetani. Blocks release of inhibitory neurotransmitters GABA and glycine. Lockjaw, muscle spasms

141

Botulinum toxin

C. botulinum. Blocks release of Ach causing anticholinerginc symptoms, flaccid paralysis. Spores found in honey.

142

TSST-1

Staph aureus superantigen causes toxic shock syndrome (fever, rash, shock)

143

Enterotoxin

Staph aureus. Food poisoning 2-6 hours after ingestion of mustards.

144

Strep exotoxin A

Erythrogenic toxin. Causes toxic shock-like syndrome (fever, rash, shock) and cardiotoxicity

145

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""

146

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""

147

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."

148

Anthrax toxin

Bacillus anthracis. EF component is an adenylate cyclase, increases cAMP. Causes edema and cell lysis

149

Pertussis toxin

Bordetella pertussis/ ADP ribosylates Gi, the negative inhibitor of adenylate cyclase, increasing cAMP. Whooping cough, lymphocytosis, hypoglycemia

150

Perfringens ?-toxin

C. Perfringens. Lecithinase causes myonecrosis and gas gangrene. Double zone of hemolysis on blood agar

151

Gram positive cell envelope components

Capsule; thick peptidoglycan cell wall gives rigid support and protects from osmotic damage; teichoic acids; cytoplasmic inner membrane

152

Gram negative cell envelope components

Capsule; Outer membrane contains LPS/lipid A; thin prptidoglycan cell wall; periplasmic space contains ?-lactamases; inner cell membrane

153

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

154

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

155

Culture media: Corynebacterium

Loffler's, tellurite

156

Culture media: lactose-fermenting enterobacteria

Pink colonies on MacConkey's agar. Lactose is the Key""

157

Culture media: vibrio cholerae

Alkaline TCBS

158

Culture media: legionella

Charcoal-yeast extract with cysteine

159

Culture media: Mycobacterium

Lowenstein-Jensen medium

160

Culture media: Neisseria and Haemophilus

Chocolate agar with factors V and X

161

Culture media: Neisseria from sites with normal flora

Thayer-Martin selective medium

162

Obligate aerobes

Nocardia, Pseudomona, Mycobacterium tuberculosis, Bacillus. Nagging Pests Must Breathe""

163

Obligate anaerobes

Actinomyces, Bacteroides, Clostridium. Anaerobes know their ABCs""

164

Intracellular pathogens

Rickettsia, chlamydia

165

Urease-positive bugs

H. pylori, proteus, klebsiella, ureaplasma

166

Characteristics of Staph aureus

Gram+ cocci in clusters, catalase+, coagulase+, ? hemolytic, ferments mannitol, salt tolerant

167

Characteristics of Staph epidirmidis

Gram+ cocci in clusters, catalase+, coagulase-, novobiocin sensitive

168

Characteristics of Staph saprophyticus

Gram+ cocci in clusters, catalase+, coagulase-, novobiocin resistant

169

Characteristics of S. pneumoniae

Gram+ catalase- lancet-chapes diplococci in chains, ? hemolytic, MOPS" optochin sensitive, bile soluble, +quellung"

170

Characteristics of Viridans strep

Gram+ catalase- cocci, ? hemolytic, optochin resistant, bile insoluble

171

Characteristics of S. pyogenes

Gram+ catalase- cocci, group A, ? hemolytic, bacitracin sensitive, PYR+

172

Characteristics of S. agalactiae

Gram+ catalase- cocci, group B, ? hemolytic, bacitracin resistant, cAMP test+

173

Characteristics of Enterococcus

Gram+ catalase- cocci, PYR+, hydrolizes esculin in 40% bile and 6.5% NaCl

174

Characteristics of Clostridium tetani

Gram+ spore-forming anaerobic rods

175

Characteristics of Clostridium botulinum

Gram+ spore-forming anaerobic rods

176

Characteristics of Clostridium perfingens

Gram+ spore-forming anaerobic rods, double zone of ? hemolysis

177

Characteristics of Clostridium difficile

Gram+ spore-forming anaerobic rods

178

Characteristics of Corynebacterium diptheriae

Gram+ aerobic club-shaped rods, V or L shapes on tellurite, metachromatic granules on Leoffler. ?-prophage contains diptheria toxin gene (lysogeny)

179

Characteristics of Bacillus

Gram+ spore-forming aerobic rods

180

Characteristics of Listeria

Gram+ rods with tumbling or actin jet motility, ? hemolytic, cold growth, facultative intracellular

181

Characteristics of Actinomyces

Gram+, long branching filaments, non-acid fast anaerobic rods

182

Characteristics of Nocardia

Gram+, long branching filaments, partially acid-fast aerobic rods

183

Characteristics of Mycobacterium tuberculosis

Acid-fast aerobic rods on Lowenstein-Jensen medium, auramine-rhodamine stainning (fluorescent apple green). Mycolic acid lipids on cell wall

184

Characteristics of Mycobacterium lepreae

Acid-fast aerobic rods, can't be cultured (obligate intracellular). Mycolic acid lipids on cell wall

185

Characteristics of Neisseria meningitidis

Gram- kidneybean-shaped diplococci, grows on chocolate agar, maltose fermenter, polysaccharide capsule

186

Characteristics of Neisseria gonorrhoeae

Gram- kidneybean-shpaed diplococci, growws Thayer-Martin, maltose non-fermenter, no polysaccharide capsule

187

Characteristics of Haemophilus influezae

Gram- cocobacillus, requires factor X and V (chocolate agar). Satellite phenomenon near staph aureus on blood agar

188

Characteristics of Pasteurella

Gram- cocobacillus, anaerobic

189

Characteristics of Brucella

Gram- cocobacillus, aaerobic, zoonosis, biowarfare

190

Characteristics of Bordetella pertussis

Gram- aerobic cocobacillus

191

Characteristics of Klebsiella

Gram- lactose-fermenting rods on MacConkey, polysacchride capsule, oxidase-

192

Characteristics of E. coli

Gram- lactose-fermenting rods on MacConkey, oxidase-

193

Characteristics of Shigella

Gram- nonlactose-fermenting rods on MacConkey, nonmotile, no H2S production, oxidase-

194

Characteristics of Salmonella

Gram- nonlactose-fermenting rods on MacConkey, highly motile, H2S producer, oxidase-

195

Characteristics of Proteus

Gram- nonlactose-fermenting rods with swarming motility, H2S producer, urease+, oxidase-

196

Characteristics of Pseudomonas

Gram- nonlactose-fermenting rods on MacConkey oxidase+, aerobic, produces green pigment pyocyanin

197

Characteristics of C. jejuni

Gram- nonlactose-fermenting curved rods with flagella, oxidase+, microaerophillic

198

Characteristics of H. pylori

Gram- nonlactose-fermenting helical rods with flagella, oxidase+, urease+, microaerophillic

199

Characteristics of Vibrio cholera

Gram- nonlactose-fermenting curved rod with flagella, oxidase+ grows on alkaline media (thiosulfate)

200

Characteristics of Francisella

Gram- facultative intracellular rods, zoonosis, biowarfare

201

Characteristics of Yersinia

Gram- coagulase+ rods with bipolar stainnning, facultative intracellular, zoonosis

202

Characteristics of Gardnerella

Gram variable rod, positive whiff fishy smell test

203

Characteristics of Bacteroides

Gram- anaerobic rod

204

Characteristics of Treponema

Gram- spirochete, spiral-shaped with axial filaments, dark microscopy

205

Characteristics of Borrelia

Gram- spirochete, spiral-shaped with axial filaments, microaerophilic

206

Characteristics of Leptospira

Gram- spirochete, spiral question mark-shaped with axial filaments

207

Characteristics of Rickettsia

Gram- (doesn't stain well) obligate intracellular rods

208

Characteristics of Coxiella

Gram- (doesn't stain well) obligate intracellular rods

209

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

210

Characteristics of Mycoplasma

Lacks peptidoglycan cell wall, does not gram stain. Cholesterols in membrane

211

Staph gastroenteritis

Nausea, abdominal pain, vomiting, followed by diarrhea 2-6 hours after ingesting enterotoxin in custards, pastries, potato salad, canned meats

212

Infective acute endocarditis

Staph aureus. Fever, malaise, leukocytosis, murmur

213

Abscess and mastitis

Staph aureus. Pain, pus, redness, edema, warmth.

214

Toxic shock syndrome

Staph aureus or GAS. Fever hypotension, scarlatiform desquamating rash on palms and soles, multiorgan failure. Produced by superantigen TSST-1 toxin

215

Impetigo

Staph aureus or GAS. Erythematous papules to bullae (staph) or honey-crusted lessions (GAS)

216

Staph pneumonia

Typical acute severe pneumonia. Associated to Ccystic Phibrosis, CGD

217

MCC surgical infections

Staph aureus. Fever with cellulitis or abscess

218

MCC osteomyelitis

Staph aureus. Bone pain, fever, inflammation, lytic bone lessions on x-rays

219

Honeymoon" cystitis"

Staph saprophyticus. 2nd MCC UTI in sexually active women. Dysuria, frequency, urgency, suprapubic pain.

220

3 MCC of ambulatory UTIs

E. coli, S. saprophyticus, Klebsiella

221

Infection of prosthetic devices and catheters

Staph. epidirmidis

222

Rx.: staph infections

Nafcillin, oxacillin. For MRSA: vancomycin

223

Pharyngitis

GAS. Abrupt onset of sore throat, fever, tonsillar abscesses, tender anterior cervical nodes. Rx.: penicillin or macrolide in case of allergy

224

Scarlet fever

GAS. Pharyngitis plus sandpaper rash (palm and soles spared), strawberry tongue, nausea

225

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.

226

Acute postsrep glomerulonephritis

GAS M12 serotype. Immunocomplex deposition on GBM (type III hypersensitivity). Nephritic syndrome: hypertension, azotemia, edema, smoky urine (hematuria).

227

3 MCC of neonatal meningitis

GBS agalactiae, E. coli, Listeria

228

Diseases caused by Strep pneumoniae

MOPS: Meningitis, Otitis media (in children), Penumonia, Sinusitis; sepsis in asplenic sickle cell anemia.

229

Strep pneumonia virulence factors

Polysacchride capsule is major factor, IgA protease cleaves mucosal IgA, teichoic acids and peptidoglycan are highly inflammatory in CNS

230

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

231

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.

232

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"

233

Disease caused by enterococcus

Urinary/billiary tract infections and subacute bacterial endocarditis following prostate or GI surgery

234

Malignant pustule

Cutaneous anthrax by B. anthracis. Painless ulcer papule with vesicles have a central eschar necrosis with erythematous border and painful regional lymphadenopathy

235

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

236

Bacillus gastroenteritis

Rapid onset gastroenteritis with watery diarrhea associated with reheated fried rice

237

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

238

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"

239

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

240

Clostridium food poisoning

Enterotoxin in reheated meat dishes causes noninflammatory watery diarrhea in 8-24 hours

241

Pseudomembranous colitis

C. difficile enterotoxin damages mucosa. Diarrhea, colitis, pseudomembrane. Associated with clindamycin use in hospitalized patients. Tx.: metronidazole

242

MCC of meningitis in renal transplant or cancer patients

Listeria

243

Granulomatosis infactisepticum

Neonatal sepsis with disseminated granulomas after in-uterus transmission of Listeria. Associated with unpasterurized milk products, cold deli meats, soft cheeses.

244

Diptheria

Diptheria toxin inhibits EF-2 and protein synthesis. Causes pharyngitis with gray pseudomembrane. Complications are larynx obstruction, myocarditis, recurrent laryngeal nerve palsy

245

Actinomycosis

Oral/facial draining abscesses with sinus tracts in tissues with low oxygenation: cervicofacial, pelvic, solitary brain abscess

246

Nocardiosis

Cavitary pulmonary mycetomas in immunocompromised and cancer patients. Cough, fever, dyspnea, cavitations.

247

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).

248

M. tuberculosis pathogenic factors

Sulfatides in cell envelope inhibit phagosome lysosome fusion. Tuberculin induces CMI with casseating granulomas.

249

Clinical features of TB

Chronic productive cough, hemoptysis, weight loss

250

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.

251

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

252

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.

253

Waterhouse-Friderichsen syndrome

Meningococemia leads to ecchymoses, DIC, bilateral adrenal infarct, shock, death.

254

Diseases caused by N. gonorrheae

Uretheral/vaginal leukorrhea; endocervicitis/PID; septic arthritis; neonatal opthalmia

255

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."

256

Legionnaires disease

Legionella. Atypical pneumonia associated with old age, immunosuppressed, smokers, water aerosols and air conditioning systems.

257

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.

258

Whooping cough

B. pertussis. Repetitive cough with inspiratory whoops, anoxia and eye hemorrhages in unvaccinated children

259

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

260

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.

261

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.

262

Helicobacter virulence factors

Motile flagella; Urease covers the bug in ammonium which neutralizes stomach acid; Mucinase aids in penetrating the mucin layer of stomach.

263

Diseases associated with Helicobacter

Chronic gastritis and 90% of duodenal peptic ulcers; gastric adenocarcinoma., gastric MALToma

264

E. coli serotypes

PITCH": EPEC (enteropathogenic=pediatric); EIEC (enteroinvasive=inflammatory diarrhea); ETEC (enterotoxigenic=traveler's diarrhea); EHEC (enterohemorrhagic=undercooked hamburgers)"

265

MCC UTI

E.coli. Colonization of uroepithelium from fecal flora. Pyelonephritis-associated pilli (p. pili) is major virulence factor and allows adherence to uroepithelium

266

2nd MCC neonatal septicemia

E. coli from maternal fecal flora infects neonate during parturition. K1 serotype capsule and endotoxin are virulence factors

267

3 MCC nosocomial UTIs

E. coli, proteus, klebsiella

268

MCC gram- sepsis

E. coli. From indwelling IV catheters

269

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.

270

2nd MCC of infantile diarrhea

EPEC (enteroPathogenic=Pediatric). Noninflamatory watery diarrhea in babies in developing countries. Adherance to M cells is virulence factor.

271

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.

272

Disease caused by EIEC

Watery inflammatory diarrhea with fever and fecal leukocytes

273

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

274

Shigellosis

1-10 acid-resistant organisms needed for infection. Invasive bloody diarrhea with fever, abdominal cramps, tenesmus.

275

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.

276

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

277

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.

278

MCC inflammatory diarrhea

Campylobacter, salmonella enterica

279

MCC infantile diarrhea

Rotavirus, EPEC

280

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.

281

Bubonic plague

Yersinia pestis. Rapidly increasing fever, regional buboes, conjunctivitis, pneumonia. Highly contagious zoonosis associated with rodents and prairie dogs.

282

Yersinia enterocolitis

Inflammatory bloody diarrhea, fever, pseudoappendicitis. Associated with cold northern climates (Michigan, Scandinavia), unpasteurized milk and pork, pet puppies.

283

Disease associated with proteus

2nd MCC nosocomial UTIs, struvite renal stones due to urease.

284

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)

285

Gardnerella vaginosis

Vaginal fishy odor and thin gray vaginal discharge. Caused by reduction of vaginal Lactobacillus when vaginal pH > 4.5. Find clue cells.

286

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.

287

Disease caused by Pasteurella

Cellulitis and lymphadenitis associated with cat bites

288

Disease caused by Haemophilus influenzae

haEMOPhilus": Epiglotitis (MCC); Meningitis in unvaccinated children (MCC); Otitis media; Pneumonia in COPD patients."

289

Painful chancroid

Haemophilus ducreyi. Chancroid and soft painful genital ulcers

290

Diseases caused by Bacteroides

Septicemia, peritonitis, abdominal abscess after trauma or emergency abdominal surgery

291

Primary syphilis

T. pallidum. Painless indurated chancre, highly contagious, heals in 3-6 weeks.

292

Secondary syphilis

T. pallidum. Condylomata lata flat wartlike perianal and mucous membrane lessions, highly contagious. Maculopapular rash

293

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""

294

Congenital syphilis

Stillbirth, keratitis, deafness, desquamating maculopapular rash

295

VDRL test

Antitreponemal antibodies in 1ary and 2dary syphilis cross-react with cow heart antigens. Sensitive but not specific.

296

FTA-ABS test

Fluorescent antibodies agglutinate treponema sample. Specific for syphilis.

297

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.

298

Leptospirosis

Myalgia, abdominal pain, hepatitis with combined jaundice. Associated with urine-contaminated waters (jet skiers and sewer workers)

299

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+

300

Q fever

Coxiella. Fever, pneumonia and granulomatous hepatitis. Weil-Felix negative

301

MCC of bacterial STD

Chlamydia trachomatis serotypes D-K

302

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.

303

3 MCC of atypical pneumonia

Mycoplasma, Legionella, Chlamydia pneumoniae

304

Walking pneumonia

Mycoplasma. MCC of pneumonia in adults 18-40 years. Atypical pneumonia with persistent hacking cough and no sputum.

305

What is a plasmid?

Extra chromosomal genetic elements non-essential for life. Contain genes for fertility, antibiotic resistance and exotoxins.

306

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.

307

What is a transposon?

Mobile genetic elements (jumping genes). From plasmid to chromosome or vice versa. Ususally associated with multiple drug resistance genes.

308

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.

309

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.

310

What is transformation?

DNA is taken up from the environment by competent bacteria and incorporated by homologous recombination.

311

F+ x F- conjugation

F+ contains conjugation genes. Sex pilus coded by F+ plasmid tranfers plasmid to F- cell. No chromosomal genes are transferred.

312

Hfr x F- conjugation

Hfr cell has plasmid integrated into the chromosomal DNA which is transferred to F- cell along with chromosomal DNA.

313

Generalized transduction

A lytic phage acquires some bacterial DNA and carries to the next bacteria after lysis. Any gene can be transduced.

314

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.

315

Autoclave

Steam under 15lbs pressure at 121 degrees celsius for 15-20 minutes. Or dry heat for 2 hours at 180 degrees celsius.

316

Membrane damaging disinfectants

Use for enveloped viruses: detergents (benzalkonium), alcohol, phenols

317

Protein denaturing disinfectants

Use for naked capsid viruses. Chlorine, iodine, H2O2, formaldehyde, alkylating agents.