Micro Term 3 Flashcards
(126 cards)
1
Q
Pox-viridae
A
Replicates in the cytoplasm
Complex, enveloped, dsDNA, icosahedral. Group I
2
Q
Herpes-viridae
A
BV, CMB, VZV, HHV 6,8
dsDNA, Icosahedral capsid, enveloped
Group I
3
Q
Rhabdo-viridae
A
Group V. -ssRNA, helical capsid, envelope, bullet-shaped. Must supply its own RNA pol (group V)
Rabies - raccoons, skunks ,bats are animal reservoirs
Transmission: bite of infected animal, sometimes aerosol by bats
Rabies receptor: ACh receptor on neurons
4
Q
Orthomixo-viridae
A
-ssRNA, helical capsid, enveloped Segmented genome, replicates in nucleus ie influenza Group V Influenza: sialic acid R on epithelial cells (cell tropism det disease)
5
Q
Retro-viridae
A
+ssRNA, icosahedral capsid, enveloped. RT, diploid. RT –>RNA/DNA hybrid. Gropu VI
6
Q
Reo-viridae
A
dsRNA, icosahedral capsid, non-enveloped (but three layers of capsid).
ie Rotavirus is a reovirus
Group III
7
Q
boceprevir
A
Blocks protease activ sit, antiviral, hep C
8
Q
saquinavir
A
blocks proteas, HIV AIDS antiviral
9
Q
Viroids
A
Virus without a capsid or envelope - only genome. small circular nucleic acid. So far only found as pathogens on plants. Replicatd by host RNA pol II. Hep D similar structure.
RNA does not code for protein, but has an enzymatic function -ribozym
ss close circle RNA
transfer via plasmodesmata from cell to cell
likely to interfere with siRNA
10
Q
Satellite viruses
A
(defective) cannot replicat without a helper virus - 100x more defective than normal viruses du to mutation
11
Q
pseudovirions
A
wrong DNA ie host cell instead of viral genome - can infect a new host but cannot replicate
12
Q
corynybacteriumd iphtheriae
A
Produces diptheria toxin encoded by existent lysogenic prophage - bacterial regulator of gene transcription responsible for turning off/on production of toxin, depending on low extracellular iron concentrations. Diphtheria toxin production does not require activation of the bacteriophage, or exiting the lysogenic cycle.
13
Q
Boceprevir
A
Hep C drug, antiviral, blocks protease activ site
14
Q
Saquinavir
A
HIV/AIDS antiviral blocks protease
15
Q
Torque Teno Virus
A
(-) ssDNA - TTV transfusion trasnmitted virus, 100% human prevalence some countries, lifelong viermia but not linked ot human disease. ssDN conv to dsDNA
16
Q
Normally sterile sites
A
Blood, CSF, Pleural fluid (chest fluid), peritoneal and pericardial fluid, bone, joint fluid, Internal body sites (brain, heart, lymph, kidney, etc.)
17
Q
Microbiata composition in disease
A
Psoriasis: Increased firmicutes to actinobacteria
Obesity: reduced bacteroidetes to firmicutes
Childhood-onset asthma: absence of gastric H pylori (esp cytotoxin associated gene A genotype)
Inflamm bowel disease (colitis) : larger populations of enterobacteriacea.
18
Q
Tryptone soy broth, nutrient agar
A
General purpose, cpts include macronutrients, micronutrients, carbon source
19
Q
Enrichment media
A
Blood agar, BCYE agar - general purpose cpts plus blood serum, antibiotics tc.
BYCE - legionella spp enhancement
20
Q
Selection & Differentiation media
A
Cpts: salts, dyes (ie brilliant green), antibiotics, etc as needed for selection or differentiation
eg. MacConkeys - enteric lactate producing bacteria, e. coli
triple sugar iron agar - identify gram negative bacilli
21
Q
Assay ie antibiotic sensitiviy medium
A
carefully defined formula ie mueller hinton agar.
- kirby bauer assay for antibiotic susceptibility profiles
22
Q
Mechanism of gamma rays (ionising radiation) as sterilization
A
Disrupts DNA
23
Q
Microwaves as sterilization
A
non-ionizing radiation, disrupts cell membranes
24
Q
Hydrogen peroxide plasma as sterilization
A
Free radicals interact with cell membranes, enzymes, or nucleic acids
25
Ozone gas for sterilization
Oxidation ie cell membranes
26
Autoclaving
Denatures and coagulates proteins
27
Susceptibility profiles of microorganisms from most to least resistant
Prions, endospores, mycobacteria, small non-enveloped viruses, fungal spores, gram negative bacteria, vegetative fungi, large non-enveloped viruses, gram positive bacteria, enveloped viruses
28
Bactria that does not have a cell wall
Mycoplasma sp.
29
Pellicle
Tough outer membrane of a protoza, replacing cell wall
30
Chitin
Cell wall of fungi. B 1-4 linked homopolymer of N-acetylglucosamine
31
Teichoic Acid
Only found in Gram + bacteria. Acidic polysacchard, polymer of ribitol or glycerol and phosphate. LTA is just TA but attached to a lipid on the cell membrane.
They are cell wall gycopolymers - roles in infection, candidates for vaccine?
32
Mycoplasma sp.
ie. Mycoplasma pneumoniae
| lack cell wall, and have cellular membrane that contains sterols
33
Mycobacterium TB
waxy outer coat (mycolic acids) with high % of lipids - don't gram stain
Results in slow growth (MGT 20-24 hrs), longer incubation times, chronic infxns. Arabinogalactan
Stained by acid fast (Ziehl-Neelsen method)
AFB positive: pink/red
Non acid fast: blue
34
Bacillus anthracis
Causes anthrax. Spores inhaled, ingested or enter wounds.
35
Clostridium tetani
Causes tetanus - spores enter anaerobic wounds
36
Clostridium botulinum
Causes botulism - anaerobic food; toxin ingested
37
Clostridium difficile
Causes PMC (pseudomembranous colitis), present in gut; can germinate when microbiome disrupted.
38
Components of endospore
Core: DNA, energy gnerating, calcium dipicolinate and SASPs for stab and protec
Spore wall: peptido
Cortex: unusual peptido - water removal
Coat: Keratin like, responsible for resistance to chemicals
Exosporium: proteins, lipids, carbs
39
Bacterial structures; capsules
```
Strongly attached, difficult to remove, highly organized, important for virulence - antiphagocytic. . Heavily hydrated, not all bacteria. Hide surface antigens and thus hide bacteria from immune system. Protects from dehydration, facilitates surface attachments.
Mostly sugars (polysaccharides) and water.
```
40
Bacterial structures; slime layer
Loosely attached, easily removed, relatively disorganized. Protect cell against dehydration, facilitates surface attachemnt
41
H. Influenzae
Capsule composition - polyribotol phosphate
| Orthomyxo family. -ssRNA, enveloped, helical. Segmented genome, replicates in nucleus.
42
Streptococcus Pyogenes
Capsule composition: hyaluronic acid (tricks immune system, recognizes)
43
K antigen
Capsular antigen
44
Atrichous
no flagella
45
Lophotrichous
flagella bunch at one end
46
Amphitrichous
Bunched flagella on both ends of bacteria
47
Peritrichous
Flagella all around cell - ie like a spider
48
H antigen
Flagella antigen
49
Borrelia burgdorferi
Lyme disease. Spirochete, build in endoflagellum
50
Treponema pallidum
Syphilis. Spirochte. Bild in endoflagellum
51
Actinomycetales
Order, main species include aerobic mycobacterium TB, mycobacterium leprae (leprosy), mycobacterium marinum (wound infections). Nocardia ie nocardia asteroides complex (nocardiosis)
Anaerobic: actinomyces
52
Mycoplasma spp
atypical bacteria. smallest prokaryotes capable of independent growth. have sterols in membrane. no cell wall
clsas name: molliculites (soft skin)
5 families : mycoplasmatacea most significant
2 key specifies: mycoplasma pneumonia, mycoplasma genitalium. Ureaplasma
53
Chlamydia sp.
Cannot survive out of living host celll, canot be culture on lab media. Small enough to pass thru bacteriological filters. Use tissue culture stains ie Giemsa.
species: chlamydia trachomatis - trachoma, STI
chlamydophila pneumonia - pneumonia
chlamydophila psittaci - ornithosis/psittacosis
Complex life cycle: elementary bodies (infectious) and reticular bodies (replicative)
54
Rickettsia sp.
Cannot survive out of host cell, cannot b cultured in lab, small to pass thru bac filter, gram stain not used - tissue stains ie Giemsa.
Rickettsia rickettsi - rocky mountain spotted fever
55
Zygomycota (fungi)
eg. Rhizopus. Some spp cause disease in humans, important cause of food spoilage
56
Ascomycota (fungi)
eg. Candida albicans. are >90% of pathogenic fungi
57
Basidiomycota
Some produce toxins or hallucigenic compounds.
58
Candida albicans
In ascomycota phylum (division) of fungi
Is dimorphic - in humans is in yeast form
In culture: mycelial
In superficial cutaneous and mucous membrane infections is yeast and pseudohyphae
59
Algae
Unicellular - diatoms, dinoflagellates
mutlicellular - seaweeds
cellulose walls, photosynthtic (chlorophyll and chloroplast)
can be an INDIRECT cause of disease - algal blooms, neurotoxins, resp irritation. bioaccumulate in fish & subsequent ingestion
ie Paralytic shellfish poisoning (PSP)
60
Prepatent period
Period between infection with a parasite and the demonstration of that parasite in the body. esp determined by recovery of an infective form oocysts or eggs from blood or feces) (similar to incubation period of bacteria) - biologically different, parasite is undergoing developmental changes in host.
61
Four groups of protozoa based on movement
Sarcodina (amoeba), mastigophora (flagellates), ciliophora (ciliates), sporozoa (adult stage not motile)
62
Lymphatic Filariasis (nematode)
Vector borne, blood associated pathogen. Endemic in 83 countries, 120 million cases - 25 mill men with hydrocoele. 15 million people with lymphedema
Tropical africa, asia, americas, pacific - 66% clustered in SE asia, remaining in Africa. 2.8 million DALYs
Wucherria bancrofti, worms invade lymph nodes,
63
Schistosomiasis
Trematode ie fluke
Snails are host - cercariae penetrate skin of humans. ie transcutaneous from wading in infected freshwater. dermatitis, Humans are reservoirs (Liver and spleen enlargement, fibrosis, inflammation, portal HTN. Chronic infection can lead to squamous cell carcinoma of bladder nad pulm HTN. )
64
Echinococcus
Hydatid disease. Cestode (tapeworm)
diagnosis: imaging, serologic testing, exam of cyst fluid
cyst formation, rupture can cause anaphylaxis.
Ingestion of eggs in food contaminated with dog feces
sheep - intermediate host.
65
Generalized life cycle of the Nematodes
3 stages: egg, larva, adult
Pre-parasitic; for living or intermediate host
parasitic: definitive host, lara to adult
66
Paralytic Poliomyelitis
Fecal oral path, intial propagation in small intestines, viral reach to mesenteric lymph nodes. Initial viremia, secondary viremia to CNS - paralysis in 1% due to slow cycle time, allowance for IgG buildup.
Poliovirus (PERCH) is a picornavirus. ie +ssRNA, icosahedra, naked. Group IV.
67
Viruses causing perinatal infection transplacentally
CMV, Parvovirus B19, Rubella Virus
68
Viruses causing perinatal infection at time of birth
Hep B, Hep C, HSV 2, HIV, HPV
69
Viruses causing perinatal infection breast feeding
CMV, Human T cell lymphotropic virus
70
Focus-forming Units (FFU)
Quantify viruses that do not lyse the cell to make PFUs. Fluorescently labeled antibodies against viral cell surface proteins.
71
Our microbiata
Actinobacteria (skin nares), Bacteroidetes (mouth, gut), firmicutes (GU, mouth, gut etc), fusobacteria (mouth), protobacteria (mouth, skin)
72
Bacterial genome properties
dsDNA, single chromosome, circular or (sometimes linear), haploid no associated proteins, ribosomes: 70s composed of 50 and 30s, genome in the nucleoid
73
mycoplasma genitalium
chromosome size 0.58 . one of the smalllest bacteria that can still grow on agar - otherwise become obligate intracellular.
74
Mannitol Salt Agar
Selective: staph not inhibited by 7% NaCl. and Differential: S. aureus looks different than S. epidermis (acid production)
75
Bordetella Pertussis
Growth requirement: nicotinamide.
| Bordet genou agar (potato extract)
76
Haemophilus sp
Growth requirement: X (hematin) and V factor (NAD+), chocolate agar contains X and V.
77
Legionella sp
Growth requirement: L-cysteine and iron
| BYCE enhances growth
78
Disinfectants and antiseptics for bacteria
Everything except quat ammonium (disinfect). Antiseptic: everything, but parachlorometaxylenol is least effective
79
Disinfectants and antiseptics for mycobacterium
disinfectants: all except iodophores are less effective, and not quaternary ammonium compounds
80
Disinfectants and antiseptics for bacterial spores
Disinfect: Only formaldehyde and glutaralehyde are completely effective. H2O2 and chlorine are partially effective.
Antiseptic: none
81
Disinfectants and antiseptics for fungi
Disinfect everything except quat ammonium only partially.
| Antiseptic: everything except triclosan less effective
82
Disinfectants for viruses
disinfect: Everything works except alcohol, phenolics, and quat are all only partially effective.
antiseptic: everything except parachorometaxylenol only partially effective
83
Algae cell wall composition
Cellulose, B(1,4) linked D glucose
84
Protozoa membrane
No cell wall - replaced by pellicle, a tough outer membrane
85
Fungi cell wall
Chitin ie B (1,4) linked homopolymer of N-acetylglucosamine (NAG)
86
Example of species with built in endoflagellum, for corkscrew attachment
Borrelia burgdorferi - lyme disease
| treponema pallidum - syphilis.
87
Asexually produced fungal spores
Mitosis only : sporangiospores, conidiospores
88
Sexually produce fungal spores
Meiosis. Ascospores (sac), Basidiospores (club). How spores form is used for phylum classification
89
Tsetse Fly
Lif cycle: only asexual repro, so both in human and in fly.
Infective stage: blood meal
Diagnostic stage: Trypomastigotes in blood, after multiplication by binary fission
90
Clinical presentations of Amoebiasis (Entamoebae histolytica)
Noninvasive intestinal infection, amebic colitis, necrotising colitis, ameboma, liver abscess.
91
Diagnosis of certain blood-borne infections
Blood smeras
Thick: concentrate RBCs, lyse - high density of parasite numbrs
Thin: monolayer, better for structural detail. ie Differentiate between species of plasmodium. See band or ring forms etc.
92
Diagnostic use of Ultrasound for parasites
Dx Echinococcosis, Cysticercosis, Onchocerciasis, Lmymphatic Filariasis (microfilariae).
Info includes abscess/cyst/space occupying lesion
Number, size, location and condition.
93
Giardiasis
G. Lamblia. Group mastigophora (flagellats)
Fecal - oral route - day care, mountain sreams. Symptoms vary with host, asymptomatic --> acute --> chronic diarrheaa
2-3 billion cases world wide, 1-2 million/year in US. Most common.
94
Sporozoa
Group of protoza (adult stage non-motile) Phya: apicomplexa
| Eg. Plasmodium (cause of malaria)
95
Plasmodium
A protoza, group sporozoa,
Cause of malaria
Exception: Protozoa that undergoes multiple fissions with sexual reproduction.
Definitive host is mosquito, not humans. ie sexual repro in mosquito.
96
Multi-stage lifecycle of most protozoa
Most have multi-stage life cycles with cyst and trophozoite forms eg. entamoebae histolytica
Trophozoite: motile, feeding stage, larger
Cyst: non-motile, resistant, smaller, multinucleated survival form.
Some (one or two) only have trophozoite stage.
97
Infective forms of intestinal protozoa transmitted by fecal-oral
Cyst, Trophozoite, oocyst
98
Infective forms of urogenital protozoa transmitted by sexual transmission
Trophozoite (t. vaginalis)
99
Infective forms of blood and tissue protozoa transmitted by insect vectors except for *
* cyst/trophozoite
pyrifiform body
*oocyst
promastigote, trypomastigote
100
Ascaris lumbricoides
Nematode (roundworm) metazoa
Reservoir: moist, warm shaded soil
Infection: ingested fertilized eggs (fecal/oral)
Diagnosis: eggs in faeces (microscope), worms in faeces mouth or nares.
Symptoms: Lungs (larvae) - asthma or pneumonia-like, cough SO wheeze. Intestine (adult worms) - diarrhea or bloody stools, Gen GI, severe: malnutrition, weight loss
101
Schistosomiasis
Trematode infection (fluke) metazoa
Reservoir: various animals ie dogs, cats, rodents, pigs, horse, goats.
Intermediate host: snails
Infection: transcutaenous ie wading in deep water. Infected cercariae swim, penetrate the skin of the human host
Diagnosis: eggs in faeces and urine
102
Echinococcus life cycle
Definitive host: SI of dogs, other canines. Becomes infected by ingesting the cyst-containing organs of infected intermediate host.
Diagnostic: Hyatid cyst in liver, lungs, etc.
Intermediate host: sheep, goats, swine, cattle, horses, camels, humans
103
Infective forms of nematodes (roundworms) metazoa
Egg, filariform larvae, 3rd stage larvae
104
Infective forms of trematodes (flukes) metazoa
Cercaria, Metacercaria
105
Infective forms of cestodes (tapeworms) metazoa
Proglottid, embryonated egg, cysticercus, cystericercoid
106
Trematode generalized life cycle
(1) miracidia - ciliated first stage larva, emerges from egg. Must penetrate intermediate host (ie snail) to continue life cycle. Followed by development of mother sporocyst.
(2) Sporocyst - larval form. Saclike srxr with germinal cells, bud off internally ,dvlp to other larval types
(3) cercariae - free swimming trematode. entry routes include skin penetration, encysting on vegetation or fish, penetrate and encyst arthropod hosts.
107
Cestode (tapeworm) generalized life cycle
Eggs from adults excreted, ingested by intermediate host, larvae develop, enter circulation and encyst, intermediate host consumed by definitive host, encysted form released in intestine; develops into adult.
108
Paratope
Antibody variable (H and L) domains which recognize and bind epitope, binds by non-covalent reversible forces
109
CDR
Complimentary detrmining regions on antibodies - 5-10 aas long, each variable domain has 3 CDRs.
CRD 3 is the most variable, closest to the C domain.
110
Rheumatic Fever
Some infections can trigger autoimmunity against self-antigens -- complication caused by group A streptococcal infections due to cross-reacting antibodies. Antibodies against strep, clear bacteria. but cross react with self antigens and get swelling of joints, and dangerous potential damage to heart.
111
VDRL (Venereal Disease Research Lab) Syphilis Test
Uses cardiolipin extracted from ox heart as antigen. Fives flocculation - precipitation clump, with anti-syphilis antibodies. Identifies early syphilis infetions (treponema pallidum). Positive CSF reaction indicative of neurosyphilis. May give false positive results - ie in drug users, malaria, leprosy, measles, viral pneumonia, SLE, relapsing fever
112
IgG
IgG's are monomers. 4 subclasses, differ in number of disulfide bonds and length of hinge region, aa sequence of constant heavy region
Most versatile Ig, can carry out all functions. Major Ig in serum (75%), major in extravascular spaces, capable of fixing complement (EXCEPT IgG4 does not)
113
IgG functions
Neutralization of microbes nad toxins. Opsonization of Ag for phago by macro and neutrophil. Activation of classical pathway of complement. Ab dependent cell cytotoxicity mediated by NK cells. Neonatal immunity - transfer across placenta and gut. Feedback inhibition of B cell activation.
114
Hepatitis B
Hepadnavirus family. dsDNA, enveloped, icosahedral
| Group VII.
115
HIV receptors
CD4 with either CCR5 or CXCR4 on Th cells, macrophages.
116
Horizontal Gene Transfer
Via defective bacteriophage, partial host genome transferred to a new host
117
Cryptic Virus
Mutation in prophage leads to dysfunctional, embedded genome. Cannot leave
118
Chemoorganotroph
Use chemical energy, organic C as energy and C source. Ie pathogenic bacteria, fungi, and protozoa
119
Action of ethylene oxide gas as a sterilization technique
Alkylates amino acids, nucleic acids, etc
120
Lysozyme targt
Targets B1-4 glycosidic bond between NAM and NAG in PG of bacteria
121
Penicillin target
Interferes with PG crosslinking by transpeptidases
122
Positive stain
Ie basic dye with positive charge. Stains negatively charged molecules, ie cytoplasm of bacteria is negatively chartged
eg crystal violet, safranin, basic fushin, methylene blue
123
negative stain
Ie negative charge acidic dye, Is repelled from negatively charged molecules ie bacterial surface so dyes outside depositing aroudn the organism leaving the microbe clear but its border stained.
124
Fungal reproduction three mechanisms
1. Production of spores (asexual - sporangio and conido) or sexual (ascospores, basidiospores)
2. Budding
3. Hyphal fragmentation
125
Asexual fungal spores (mitosis only)
sporangiospores, conidiospores
126
Sexual fungal spores (meiosis)
Ascospores, basidiospores
