Microbiology Flashcards
1
Q
Systemic Mycocies
A
- 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
Q
Amphoteracin B
A
- 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
Q
Azoles
A
- 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
Q
Histoplasmosis
A
- 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
Q
Blastomyces
A
- 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
Q
Coccidiodes
A
- 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
Q
Paracoccidoides
A
- Seen in central america and mexico
- Pneumonia like illness
- Captains wheel
8
Q
Tinea Versicolor
A
- 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
Q
Dermatohytes
A
- Cause tinea of many regions of body
- Ringworm, athletes foot, seborrheic dermatitis, etc
- KOH prep to visualize
10
Q
Sporotrix
A
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
Q
Candida
A
- 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
Q
Aspergillous
A
- 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
Q
Cryptococcus Neoformans
A
- 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
Q
Muccor
A
- 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
Q
Pneumocystsis Carini
A
- 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
Q
Pentamadine
A
-Can be used in a number of fungal and protozoal infections, but is classic for pneumocystsis
17
Q
Giardia
A
- 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
Q
Entaomeba Histolytica
A
- 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
Q
Cryptosporidium
A
- Protozoa transmitted by cyst ingestion in water
- Causes watery diahrrea especially in AIDS patients
- Cysts are acid fast
- Tx netazomanide
20
Q
Toxoplasmosis
A
- 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
Q
Nageria Fowleri
A
-Protozoa in warm freshwater that enters through cribiform plate and causes devastating meningoencephalitis
22
Q
Tryanasomes
A
- Protozoa
- Transmitted by tetse flybite
- Cause african sleeping sickness
- Recurrent fever, fatigue, somnolence and coma
- Tx is suramine and melarsoprol
23
Q
Plasmodium Falciprum
A
- 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
Q
Plasmodium Ovale/Vivax
A
- 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
Q
Quinidine Drugs
A
- 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
Q
Babesia
A
- 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
Q
Trypanasome Cruzi
A
- 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
Q
Leishmaniasis
A
- Transmitted by sandfly bite in middle east and africa
- Cutaneous form has an ulcer
- Visceral form fevers, HSM and pancytopenia
29
Q
Trichamonas
A
- 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
Q
Roundworm Treatments
A
- 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
Q
Enterobus
A
- Fecal oral transmission, consumption of eggs
- Causes perianal pruritis
- Scotch tape test
32
Q
Ascaris
A
- Fecal oral transmission
- Intestinal infection
33
Q
Strongyloides
A
- Enter through penetration of skin in foot
- Intestinal Infection causing microcytic anemia
34
Q
Anclystoma
A
- Enter through penetration of skin in foot
- Intestinal Infection causing microcytic anemia
35
Q
Necator
A
- Enter through penetration of skin in foot
- Intestinal Infection causing microcytic anemia
36
Q
Onchocerra
A
- River Blindness
- Black Fly
37
Q
Wucheria Bacnrofti
A
-Mosquito causing elephantitis
38
Q
Fecal Oral
A
-Enterobus, Asscaris
39
Q
Penetration
A
-Necator, Ancylomata, Strongyloides
40
Q
Tapeworms
A
- Usually contracted by eating cysts or larva in meat
- treat with praziauantal
41
Q
Taniea Soleum
A
- Pork meat cysts
- Can cause neurocystercosis
42
Q
Diphyllobathrium Latum
A
- Fish
- B12 deficency leading to megaloblastic anemia
43
Q
Echinococcus
A
- Dog feces
- Leads to Liver cysts and may cause anyphylaxis
44
Q
Flukes
A
-Tx with praziquantal, have large international burdern
45
Q
Schistosoma
A
- 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
Q
Clonorhis
A
- From undercooked fish
- Causes cholangitis that may lead to pigmented gallstones
- Can lead to cholangiosarcoma
47
Q
Paragoniumus
A
-Ingestion and travel through portal system causing hemoptysis
48
Q
Viral Recombination
A
- Requires significant homology
- Most common in DNA viruses
49
Q
Reassortment
A
- Shuffling of genetic material
- Requires segmented genome
- Commonly seen in influenza
50
Q
Complimentation
A
- 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
Q
Phenotype Mixing
A
- Envelope proteins from one virus are used by another
- Best example is HBV providing envelope proteins for Hep D virus
52
Q
Live Vaccines
A
- MMR
- Sabin
- Yellow Fever
- Smallpox
- Influenza intranasal
- VZV
53
Q
Killed (RIPA)
A
- Salk
- HAV
- Rabies
- Flu subQ
54
Q
Recombinant
A
- HBV
- HPV
55
Q
DNA genomes
A
- 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
Q
RNA genomes
A
- 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
Q
Herpes Viruses Overview
A
- 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
Q
HSV-1
A
- 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
Q
HSV-2
A
- 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
Q
VZV
A
- 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
Q
EBV
A
- 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
Q
CMV
A
- 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
Q
HHV-6 Roseola
A
-High fever (may cause siezures) that resolves and is followed by a diffuse macular rash
64
Q
HHV-8
A
- Gamma virus that lies dormant and does not cause acute infection
- Kaposi Sarcoma in AIDS patients. Tumor of lymphatic endothelium
65
Q
Acyclovir
A
- Activated by viral TK leading to chain termination
- Used for HSV, VZV encephalitis
- Does not kill dormant viruses
- Minimal S/E
66
Q
Ganciclovir
A
- Activated by CMV TK leading to inhibition of DNA pol and chain termination
- Nephrotoxic and pancytopenia
67
Q
Foscarnet
A
- 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
Q
Cidofivir
A
- 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
Q
Hepadenovirus
A
- HBV
- Recombinant vaccine available with HbSAg
- Partially duplexed DS DNA
- Replicates in nucleus and contains a reverse transcriptase
70
Q
Adenovirus
A
- 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
Q
Parvovirus
A
- 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
Q
Papilloma
A
- 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
Q
Polyoma
A
- DS circular DNA virus
- JC virus causes PML demylination and eosinophilic inclusions in AIDS pts
- BK virus causes renal disease in immunosupressed patiets
74
Q
Poxvirus
A
- 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
Q
Negtive Stranded DNA Viruses
A
- 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
Q
Reovirus
A
- 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
Q
Picornovirus
A
SS positive RNA naked, fecal oral route except rhinovirus which is respiratory droplets
78
Q
Poliovirus
A
-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
Q
Echovirus
A
-Can cause GI upset and aeseptic meningitis
80
Q
Coxackie Virus
A
-Causes devils grip, hand foot and mouth disease, and myocarditis that will commonly result in dilated cardiomyopathy
81
Q
Hepatitis A virus
A
- Causes an acute ALT driven jaundice illness, rarely deadly
- Fecal oral transmission
- Commonly assymtomatic if caught in childhood
82
Q
Rhinovirus
A
- Acid labile unlike rest of picornoviruses
- Common cause of the common cold
83
Q
Hepevirus
A
- Hepatitis E virus
- Positive stranded naked (Fecal Oral) RNA
- Causes mild illness in most, and severe illness in pregnant
84
Q
Calicivirus
A
- Norovirus
- + SS RNA fecal oral transmission
85
Q
Flavivirus
A
- Enveloped positive sense RNA
- Hep C
- Yellow Fever: GI hemorrhage and Jaundice
- Dengue: Breakbone fever and then hemorrhagic
- Encephalitis
86
Q
Togavirus
A
- 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
Q
Retrovirus
A
HIV
-HTLV-1: T cell lymphoma in a japanese or carribean man
88
Q
Coronavirus
A
- Common Cold
- SARs
89
Q
Orthomyxoviruse
A
- 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
Q
Paramyxo
A
SS negative sense RNA replicate in nucleus
91
Q
Measles
A
- 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
Q
Mumps
A
Parotiditis, orhitis, Meningitis
-Can cause sterility in men in adolescnets
93
Q
Parainfluenza
A
-Infection characterized by barking cough
94
Q
RSV
A
-Bronhiolitis and severe infection in infants and young children, treat with ribaviran
95
Q
Ribaviran
A
- Can be used for RSV and Croup
- IMP dehrydrogenase inhibitor that leads to decreased GMP levels and stops viral replication
96
Q
Rhabdovirus
A
- 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
Q
Bunyavirus
A
- Hantavirus: Hemorrhagic fever seen in southwest, transmitted by rats
- ss - RNA segmented
98
Q
Delta virus
A
-Lacks proper envelope proteins to infect cells, when infection occurs with HBV then phenotypic mixing occurs and infection can take place
99
Q
HBV
A
- Replicates in nucleus, partially duplexed circular, contains reverse transriptase
- Integrates into genome and becomes chronic in 20% often have an acute jaundice phase
100
Q
HCV
A
- 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
Q
HIV genes and proteins
A
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
Q
Testing
A
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
Q
HIV virology
A
Enveloped positive strand RNA that has a diploid genome
-Reverse transcrpitase activity
