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Flashcards in Microbiology Deck (103):
1

Systemic Mycocies

-Organisms are yeast at body temperature and are mold at room temperature
-Tx is amphoteracin B for systemic and itraconazole for cutaneous
-Generally cause a granulomatous response, can look like TB
-Person to person transmission does not occur (unlike TB)
-Can occur in healthy people in contrast to more opportunistc infections

2

Amphoteracin B

-Very strong antifungal reserved for systemic infections
-Binds ergosterol in membrane and makes membrane leaky leading to death
-Must supplement K and Mg
-Causes serious and common nephrotoxicitiy, also causes very common hypersensitivity and chills, arrythmia, etc
-Does not cross BBB and so given intrathecally if intended for brain infections

3

Azoles

-Given topically for cutaneous fungal infections
-Inhibit the production of ergosterol by inhibiting P450 like enzyme
-Main S/E relate to inhibition of CYP
-Decrease all steroid synthesis leading to gynecomastia and hypoglycemia (cortisol)
-Fluconazole can be given as prophylaxis in AIDS patients against systemic candida and cryptoccal meningitis

4

Histoplasmosis

-Dimorphic fungi
-Most common in the midwest
-Causes pneumonia with casseating granulomas in lung
-Most commonly contracted from bird and bat droppings (Splunkers disease)
-Histo oganisms will be inside macrophages

5

Blastomyces

-Dimporphic fungi
-Occurs along mississippi river area
-Broad based budding yeast not in macrophages
-Generally starts as pulmonary infection and can spread to skin and bone

6

Coccidiodes

-Dimorphic fungi
-Exists as spherule and then makes endosproes (large)
-Contracted in southwest USA
-San Jouaqin Fever: COmonly get a influenza like illness with rash
-Incidence increases after earthquakes

7

Paracoccidoides

-Seen in central america and mexico
-Pneumonia like illness
-Captains wheel

8

Tinea Versicolor

-Maleszia Furfur infection
-Causes breakdown of lipids which leads to melanocyte toxicity and caues hyper or hypopigmentation
-COmmonly seen in hot and sweat
-KOH prep to visualize
-Treat with topical drugs

9

Dermatohytes

-Cause tinea of many regions of body
-Ringworm, athletes foot, seborrheic dermatitis, etc
-KOH prep to visualize

10

Sporotrix

Dimorphic Fungi
-Cigar shaped and lives on vegetation, infection when stuck with thorn
-Local pustule with ascending lymphangittis that follows lymphatics
-Tx: Itraconazole and KI

11

Candida

-Normal Commensal
-Yeast that buds with germ tubes (Pseudohyphae), infectous form is mold form
-Causes most infections in immunocompromised
-Vaginitis (especially in diabetics)
-Esophagitis and thrush in immunocompromised and steroid inhalers
-Diaper rash
-Can cause endocarditis in IV drug users
-Chronic Mucocutaneous Candidiasis is indicaative of T cell disorder
-Systemic in AIDS patients (Neutrophils stop)
-Treatment is Azoles for cutaneous
-Systemic give amphoteracin B or caspofungin (inhibits B glucan synthesis of cell wall) Caspofungin has less systemic side effects and is mainly histamine mediated flushing and GI upset

12

Aspergillous

-Non dimorphic, only exists as mold form
-Branches at 45 degree hyphae
-Higher risk in patients with CGD
-Allergic Bronchopulmonary Aspergillosus: Type I and type 3 hypersensitivity seen in patients with asthma, CF, and CGD. Can lead to bronchiectasis. (Tx is steroids and antifungals)
-Fungus ball can infect lungs in an old TB cavitary lesion.
-Aflatoxins cause HCC

13

Cryptococcus Neoformans

-Non dimorphic fungi that has a large capsule and can be detected by india ink and latex agglutination
-Enters through lungs and spreads hematogenously to the meninges
-Pigeon droppings is the most likely source
-Causes meningitis in AIDS pts
-May also cause penumonia in AIDS patients
-Prophylax with ketocolanazole
-Tx: Intrathecal amphoteracin B

14

Muccor

-Mold monomorphic fungi
-RIbbon like with branches at 90 degrees
-Only infects DKA and leukemia patients
-Requires elevated glucose and ketonse to invade vascular walls
-Starts as black eschar that enters through cribiform plate causing a frontal lobe abcess
-TX: surgical

15

Pneumocystsis Carini

-Yeast that stains with methamine silver stain
-Common in AIDS patients and need to prophylax with TMP/SMX when get below 200
-Causes a diffuse interstitial type of pneumonia that can be rapidly fatal
-Tx: Dapsone (PABA analog),, Pentamadine, and TMP/SMX

16

Pentamadine

-Can be used in a number of fungal and protozoal infections, but is classic for pneumocystsis

17

Giardia

-Protozoa
-Mobile trophozite contracted from consuming cysts in water
-Causes a foul smelling greasy diahrrea because of adherence to wall.
-Treat with metronidazole
-Dx with cysts and trophozites in stool

18

Entaomeba Histolytica

-Protozoa
-Causes ameobic Dystentery with bloody stool
-Also causes liver abcess (RUQ pain) and can cause duodenal ulcers
-Cysts ingested in water
-Trophozites may have RBC in cytoplasm, multinucleated
-Tx: Metronidazole

19

Cryptosporidium

-Protozoa transmitted by cyst ingestion in water
-Causes watery diahrrea especially in AIDS patients
-Cysts are acid fast
-Tx netazomanide

20

Toxoplasmosis

-Protozoa
-Can cause ring enhancing lesions in AIDS patients with focal neurologic signs.
-Most commonly transmitted by ingesion of meat containing cysts, can also be caught from cat feces
-Causes mild disease with cervical lymphadenopathy in female
-Can cross placenta and cause: Chorioreitinits (may lead to blindness), Hydropcephalus, Calcifciatoins
-Tx: Sulfazadine and pyramethamine

21

Nageria Fowleri

-Protozoa in warm freshwater that enters through cribiform plate and causes devastating meningoencephalitis

22

Tryanasomes

-Protozoa
-Transmitted by tetse flybite
-Cause african sleeping sickness
-Recurrent fever, fatigue, somnolence and coma
-Tx is suramine and melarsoprol

23

Plasmodium Falciprum

-Transmited by anopheles mosquito
-Causes devastating cerebral malaria caused by blockage of brain, lung, kidney vasculature by RBC fragments
-24 hour or irregular hemolysis
-Fever, anemia, aches
-Tx is chloroquine and mefloquine if resistant

24

Plasmodium Ovale/Vivax

-Malaria with 48 hour cycle
-Anemia and fever that is less severe
-Can be dormant as hypnozite in liver, must add primaquine to rigemin

25

Quinidine Drugs

-Prevent heme polymerase in RBC and prevent destruction
-Choloroquine is strong and standard, mefloquine added for resistant strains and primaquine added for liver hypnozites
-Commonly cause hemolysis in G6PD patients

26

Babesia

-Protozoa that causes north american malira like illness
-Transmitted by Ixodes tick along with lyme disease
-Maltese cross appearance in RBC
-Worse in patients who are asplenic
-Tx: Aithromcin and atovaquone

27

Trypanasome Cruzi

-Causes chagas disease
-Transmitted by the reduviid bug in central america causes romana sign or unilateral swelling of eye
-Causes esophageal dysmotility and megacolon due to invasion of neural plexus
-Causes DCM
-Nifurtimox

28

Leishmaniasis

-Transmitted by sandfly bite in middle east and africa
-Cutaneous form has an ulcer
-Visceral form fevers, HSM and pancytopenia

29

Trichamonas

-Green foul smelling vaginal discharge, frothy
-Wet mount will show mobile trophozites in contrast to the clue cells of gram negative bacteria in gardenella vaginalis
-Tx: Metronidazole

30

Roundworm Treatments

-Bednazoles: Iinhibit tubulin synthesis and prevent MT driven consumption
-Praziquanal: Ca influx paralyzes and causes worms to fall off intestinal tract
-Ivermectin: Inhibits Neurotransmission and makes them fall off
-Diethylcarbamazine: Causes AA dysfunction leading to increased inflammation

31

Enterobus

-Fecal oral transmission, consumption of eggs
-Causes perianal pruritis
-Scotch tape test

32

Ascaris

-Fecal oral transmission
-Intestinal infection

33

Strongyloides

-Enter through penetration of skin in foot
-Intestinal Infection causing microcytic anemia

34

Anclystoma

-Enter through penetration of skin in foot
-Intestinal Infection causing microcytic anemia

35

Necator

-Enter through penetration of skin in foot
-Intestinal Infection causing microcytic anemia

36

Onchocerra

-River Blindness
-Black Fly

37

Wucheria Bacnrofti

-Mosquito causing elephantitis

38

Fecal Oral

-Enterobus, Asscaris

39

Penetration

-Necator, Ancylomata, Strongyloides

40

Tapeworms

-Usually contracted by eating cysts or larva in meat
-treat with praziauantal

41

Taniea Soleum

-Pork meat cysts
-Can cause neurocystercosis

42

Diphyllobathrium Latum

-Fish
-B12 deficency leading to megaloblastic anemia

43

Echinococcus

-Dog feces
-Leads to Liver cysts and may cause anyphylaxis

44

Flukes

-Tx with praziquantal, have large international burdern

45

Schistosoma

-From Snails
-Penetrates skin
-Causes LIver and spleen Granulomas
-S Heamatobium can cause squamous cell bladder cancer (Different from transitional which is commonly seen)

46

Clonorhis

-From undercooked fish
-Causes cholangitis that may lead to pigmented gallstones
-Can lead to cholangiosarcoma

47

Paragoniumus

-Ingestion and travel through portal system causing hemoptysis

48

Viral Recombination

-Requires significant homology
-Most common in DNA viruses

49

Reassortment

-Shuffling of genetic material
-Requires segmented genome
-Commonly seen in influenza

50

Complimentation

-Two similair viruses complement each other with a functional protein
-Defectiv protein in one virus is replaced by another.
-Not an exchange of genetic material

51

Phenotype Mixing

-Envelope proteins from one virus are used by another
-Best example is HBV providing envelope proteins for Hep D virus

52

Live Vaccines

-MMR
-Sabin
-Yellow Fever
-Smallpox
-Influenza intranasal
-VZV

53

Killed (RIPA)

-Salk
-HAV
-Rabies
-Flu subQ

54

Recombinant

-HBV
-HPV

55

DNA genomes

-All are double standed except for picorno (requires S phase)
-All replicate in nucleus except Pox
-All are infective on own except for pox and HBV
-All are haploid

56

RNA genomes

-All are single stranded except for reovirus
-POsitive sense is same as mRNA and is infectous on its own
-Negative requires virus to bring own transcription and translation machinery
-All replicate in cytoplasm except for retroviruses and influenza
-All are haploid except for retroviruses

57

Herpes Viruses Overview

-DS DNA that replicates in the nucleus and is enveloped with the nuclear membrane
-Tzank smear will be positive
-Alpha infect epithelial and lie dormant in sensory ganglia
-Gamma transform cells and can cause cancer (EBV and 8)
-Beta multitropic and lie dormant in other cels (CMV, HHV-6)
-Multinucleated giant cells
-Cowdry A- nuclear incluions

58

HSV-1

-Alpha infects mouth and lies dormant in trigeminal ganglia
-Causes gingivostomatitis, cold sores
-Number one cause of retinitis that leads to blindness
-Temporal Lobe Encephalitis

59

HSV-2

-Infection through sexual contact and lies dormant in sacral ganglia
-Causes painful vesicular rash on genitals
-Can be transitted to babies, recomneded to do C section
-Congential will either be limited to the skin, or also the viscera, or also the CNS. VIsceral and CNS involvment carry poor prognosis

60

VZV

-Alpha virus, Infection through respoiratory route
-Chicken pox as a kid will be asynchronous rash, do not give aspirin as this could precipitate Reye's Syndrome
-Dormant in dorsal root ganglia
-Can reactivate and cause shingles.
-Can also cause encephalitis and pneumonia although not prototypical
-Live attenuated Vaccine

61

EBV

-Gamma virus that infects B cells through CD21 (cd3 receptor)
-Heterophile positive mono with atypical CD8 cells. Increased CD8 to CD4 ratio. Posterior cervical lymphadenopathy, HSM that can rupture. If given penicilin can get a rash, does not mean allergic to penicilin
-Causes nasopharyngeal carcinoma, Hodgkins Lymphoma, Burkitts lymphoma
-Hairy Leukoplakia

62

CMV

-Beta virus that can infect a number of cella
-Lies dormant in mononuclear cells
-Monospot negative mono
-Congenital infection: Micropcephaly, rash, thrombocytopenia, siezures, HSM. Can cause long term hearing or vision loss and retardation
-Common cause of pneumonia in transplant patients and AIDS
-Also can cause blindness in AIDS patients
-Most commonly transfered infection from blood and organs
-Owls eye inclusions

63

HHV-6 Roseola

-High fever (may cause siezures) that resolves and is followed by a diffuse macular rash

64

HHV-8

-Gamma virus that lies dormant and does not cause acute infection
-Kaposi Sarcoma in AIDS patients. Tumor of lymphatic endothelium

65

Acyclovir

-Activated by viral TK leading to chain termination
-Used for HSV, VZV encephalitis
-Does not kill dormant viruses
-Minimal S/E

66

Ganciclovir

-Activated by CMV TK leading to inhibition of DNA pol and chain termination
-Nephrotoxic and pancytopenia

67

Foscarnet

-Does not need to be activated by TK and causes inhibtion of viral DNA pol
-Used in patients refractory to Acyclovir or gancylovir
-Causes increased risk of nephrotoxicity

68

Cidofivir

-Similar to foscarnet, does not require TK activation and inhibits DNA pol
-For resistant strains
-Serious nephrotoxicity, given with probenacid and saline to minimize damage

69

Hepadenovirus

-HBV
-Recombinant vaccine available with HbSAg
-Partially duplexed DS DNA
-Replicates in nucleus and contains a reverse transcriptase

70

Adenovirus

-Naked DS DNA
-Pneumonia in military recruits, often given adenovirus orally that is virulent to prevent infection in baracks
-Febrile pharyngitis that is often accompanied by conjunctivits (Swimming Pool Pink Eye)
-Can cause hemorrhagic Cytitis in Kids

71

Parvovirus

-SS naked DNA virus
-Causes fifths disease, children get slapped cheek appearnace
-Caused by immun complex deposition
-Asplenics can cause an aplastic crisis
-ADults can cause arthritis like symptoms that are caused by immune complex deposition

72

Papilloma

-DS circular DNA
-HPV6,11 cause condyloma accumunata most commonly on the genitals and can be on larynx
-HPV 16,18 cause CIN from koilocytic dysplasia. E6 causes an inhibition of P53 and E7 causes an inhibition of Rb
-Recombinant Vaccine Available

73

Polyoma

-DS circular DNA virus
-JC virus causes PML demylination and eosinophilic inclusions in AIDS pts
-BK virus causes renal disease in immunosupressed patiets

74

Poxvirus

-DS linear DNA that replicates in the cytoplasm
-Brings own DNA and RNA polymerase
-Smallpox
-Molluscum Contagiousum: Umbilicated skin infection seen in kids and as an STD

75

Negtive Stranded DNA Viruses

-Must transcribe to positive sense, like mRNA, negative must cary own polymerase
-Segmented can undergo reassortment
-General rule is that envelopes are less hardy and tend to be parenteral or respiratory infection

76

Reovirus

-DS linear segmented RNA, non enveloped
-Rotavirus: most common cause of diahrrea worldwide. Vaccine of components exists. Infection causes villus atrophy and watery diahrea that leads to decreased K and Na leading to dehydration
-Coltivirus: Colorado Tick Fever

77

Picornovirus

SS positive RNA naked, fecal oral route except rhinovirus which is respiratory droplets

78

Poliovirus

-Fecal oral transmission, majority confined to mild cold like or GI illness, but a small percentage go on to involve anterior horn cells and cause lower motor neuron weakness and asiculations

79

Echovirus

-Can cause GI upset and aeseptic meningitis

80

Coxackie Virus

-Causes devils grip, hand foot and mouth disease, and myocarditis that will commonly result in dilated cardiomyopathy

81

Hepatitis A virus

-Causes an acute ALT driven jaundice illness, rarely deadly
-Fecal oral transmission
-Commonly assymtomatic if caught in childhood

82

Rhinovirus

-Acid labile unlike rest of picornoviruses
-Common cause of the common cold

83

Hepevirus

-Hepatitis E virus
-Positive stranded naked (Fecal Oral) RNA
-Causes mild illness in most, and severe illness in pregnant

84

Calicivirus

-Norovirus
-+ SS RNA fecal oral transmission

85

Flavivirus

-Enveloped positive sense RNA
-Hep C
-Yellow Fever: GI hemorrhage and Jaundice
-Dengue: Breakbone fever and then hemorrhagic
-Encephalitis

86

Togavirus

-Rubella
-Positive ssmRNA enveloped
-Infection that has rash as a hallmark that spreads from head but does not involve hands and feet. Post auricular lymphadenopathy and arthalgias. Ususally less severe than measles, and not preceeded by high fever like roseolla (HHV-6)
-Congenital: Deafness, blindness, PDA and Pulmonary stenosis, can also have a rash. Worse if infection in the first trimester (embryonic period)

87

Retrovirus

HIV
-HTLV-1: T cell lymphoma in a japanese or carribean man

88

Coronavirus

-Common Cold
-SARs

89

Orthomyxoviruse

-Influenza is segmented negative strand RNA that replicates in the nucleus (only RNA to do so)
-Hemaglutinin attaches to sialic acid and neuraminidase cleaves the bond allowing for infection
-Most common cause of death is a bacterial superinfection on top (H flu and S aureaus)
-Antigenic drift is from point mutations and antigenic shift is from reassortment
-Vaccine is killed if subQ and live attenuated if intranasal

90

Paramyxo

SS negative sense RNA replicate in nucleus

91

Measles

-Severe Coryza(cold), symtptoms, conjunctivitis and rash that starts in face and moves to body, involves hands and feet and no postauricular lymphadenopathy as seen in rubella (toga)
-SPSE: Defective virus that leads to death 10 years after infection
-Can cause giant cell pneumonia in immunocompromised
-Koplick spots, lacks nueraminidasae

92

Mumps

Parotiditis, orhitis, Meningitis
-Can cause sterility in men in adolescnets

93

Parainfluenza

-Infection characterized by barking cough

94

RSV

-Bronhiolitis and severe infection in infants and young children, treat with ribaviran

95

Ribaviran

-Can be used for RSV and Croup
-IMP dehrydrogenase inhibitor that leads to decreased GMP levels and stops viral replication

96

Rhabdovirus

-Rabies, ss enveloped negative strand
-Most commonly by bats, foxes, etc
-Bite infection leads to retrograde transport until it reaches CNS. Uses AchR to attach
-Negri bodies in purkinje cells of cerebellum
-Photophobia, hydrophobia, somnolence, coma and death
-Treat with intrabdominal vaccination and antibodies Ig
-Further away the better the prognosis

97

Bunyavirus

-Hantavirus: Hemorrhagic fever seen in southwest, transmitted by rats
-ss - RNA segmented

98

Delta virus

-Lacks proper envelope proteins to infect cells, when infection occurs with HBV then phenotypic mixing occurs and infection can take place

99

HBV

-Replicates in nucleus, partially duplexed circular, contains reverse transriptase
-Integrates into genome and becomes chronic in 20% often have an acute jaundice phase

100

HCV

-Postive ssRNA enveloped
-IV drug users
-80 percent chronic, no retrovirus but chronic inflamation leads to cirrhosis and cancer
-cryoglobulins can cause serum sickness and renal disease, also associated with lichen planus

101

HIV genes and proteins

Env: GP160 cleaved into gp120 and gp41. gp120 binds to CCR5/CXCR4 and CD4 and allows gp41 to assist in fusion
gag: Structural genes, gp24 is nuclear capsid, p17 is associated with envelope
pol: polymerase, protease, integrase
-CCR5 mutations can provide protection

102

Testing

ELISA is sensitive but not specific
Western blot is specific but not sensitive
-Both test look for antibodies in serum, can lead to false negative in acute stage and false positive in baby born to infected mother

103

HIV virology

Enveloped positive strand RNA that has a diploid genome
-Reverse transcrpitase activity