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130 Cards in this Set
- Front
- Back
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6a Human - Bacteria interactions |
Namaste |
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What is the metagenome and why is it important? |
Genome of us and our microbiota important cause since they dig stuff ... |
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what are gnotobiotic animals good for? |
these animals we know they're entire flora, so can deduce effects of diff microbes on an org |
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What sort of conditions does the skin provide? |
Varies, dry, moist, sebaceous (oily) but generally slightly acidic, low water activity, salt and may contain antimicrobials |
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Certain Betaproteobacteria are used in a dry wash agent? Explain |
oxidizes ammonium |
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What's the pH of the mouth? |
neutral |
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What are the two main difficulties for microbes living in mouth? |
Must resist mechanical removal and saliva enzymes - lysozyme and ROS producing lactoperoxidase |
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Mouth microbes are mostly ___ robic, and mostly what phylum ? |
fac aerobic firmicutes |
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ileum, which is more alkaline last part of small intestine, has more microbes |
sure does |
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Large intestine mostly what type ? |
bacteroidetes and gram+ |
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Why was it hard to find probiotic linked to benefit org? |
Hard to sample small intestine, where most absoption occurs |
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Why does pH decrease again after start of large intestine? |
ferm products |
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What do bact in small intestine digest? |
simple sugars |
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Why is there less microbiots near intestinal lamina? |
Muscous layer contains many host secrecetion enz and defesnse enz Planeth cell release IgA ox and ROS |
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What Crohn's disease? |
microbes imbalance, |
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Is it true that the nose, nasopharynx or oropharynx harbours potenially pathogenic bact? |
yessim |
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Any flroa in lower resp tract? |
no, should be stable |
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What contributes to unique vaginal microbe community? |
Firmicutes org releases lactic acid and inhibs certian |
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What is infection defined as ? |
when a host is supporting a parasite |
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Virulence is a measure of ? |
pathogenicity |
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What is the str or method of non specific adherence? |
glycocalyx, slime layer surrounds host cells |
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What does covalent adherence differ from non-specific? |
covlent involves pili or fimbria for specific tighter binding |
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When does invasion and occur and where is it often asc? |
after colonization, in wounds or mucous membranes of diff tracts |
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septicimia results in? |
massive inflammation and death |
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How can Neissieria sp downregulate immune respone? |
If bound to T cells, they bind, then trigger cytoskeletal rearrangement to phagocytis |
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What is that system known as ? |
Type III secretion - injects proteins |
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What are pathogenic islands |
genes that encode virulence factors. spreadable by horizontal gene transfer G+C content differs |
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Can a host protect itself from exotoxins? |
yes, it may release antibodies |
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Type I toxins - |
act from cell surface |
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Type II toxins - |
are membrane damaging or cytolytic |
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Type III |
intracellular |
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What type of toxins are AB? |
III |
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Generally what are exotoxins? |
heat-labile proteins released into surrounding by mostly gram + |
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What type of tox is a superantigen and what can it result in? |
I, toxic shock, acitvated way too much immune resp |
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where do endotoxins come from? |
LPS portion of gram- when lysed |
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what are zoonoses? |
pathogens that can be transmitted to humey from animales |
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What did Semmelweis realize in the mid 1800s? |
That pathogens can be transmitted, based on obs that woman were 4x likely to contract disease when laboured by physicians, who were also handling sick or dying ppl |
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What 3 ways can vectors be transmitted? |
external (mechanical) internal (harbourage) internal (biological) |
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What is necessary for direct detection sample |
taken from site of infection, sufficient sample size, and metabolic cond must be maintianed |
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What are pro/cons of direct detection |
pro - no incubation time con - sensitivity low, e.g. TB hard to get sample |
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What is the difference b/w direct and indirect immunofluorescence ? |
direct, bacteria specific AB are flur labelled indirect bact AB bind, then flur labelled AB bind to bact AB |
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Describe a direct detection enzyme immunassay |
Assay kit colour-antibodies bind antigen from patient sample AB bound to an area also bind antigen colour consdenses in said area |
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How does indirect vary ^ ? |
assay AB bind patien AB |
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Breifly how does an pregnancy test work? |
assay AB bind patient antigen and can then bind to first set of bound ABs as they progress along the stick. On binding colour change otherwise AB will cont and bind diff AB and colour chagne |
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What is a CT, cut off threshold? why is a lower Ct better for master mix? |
min # cycles in qPCR to obs fluresnce from sample measn less DNA req |
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What is strep pyogenes ? |
throat infection, B-hemly can lead to further disesae - scarlett fever |
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What about strep pneumonnia is the prob? |
capsule, which can also change itself to be inantigenic A-hem |
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how can diptheria toxin be transmitted and what does it do? |
airborn affects EF-2 - translation |
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treatment ? |
formaldehyde - xlinks prots |
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What does pertussis cause ? how ? |
whooping cough 2 toxins - endo and exo exo - induces cAMP synth |
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How is TB toxic and why is a hard to treat? |
macrophaged by immune cells cell memrbane has toxic bits but also forms hydrophobic layer that is hard to pen treatment v long |
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What are tubercles? Are they bad? |
macrophage and TB aggregate in lower lungs, 1' infection. Not disease state |
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What are granulomas? |
progression of tubercles if disease is not controlled |
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What do they result in? |
extensive lung dmg |
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What's a challenge in IDing TB in lab? |
grows v slowly |
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How does Leprosy treatment vary from TB? |
Easier to treat once detected |
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Is leprosry sim to TB, how so ? |
acid fast hard to kill slow grow |
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What is meningites ? |
inflammation of brain and spinal membranes |
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what is meningococcemia |
intravascular coagulation, tissue desctruction |
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What's unique in mening treatment? |
Usually respond to clinical symptoms b4 clinical ID |
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What does mening ID constist of? |
lumbar puncture to collect cerebrospinal fluid |
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What is growth med? and gram ? |
gram- dipplococci on Thayer-martin |
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What components of staphylococci contribute to pathogenicity? |
techoic acids and PPG layer |
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What do coagulase + staphy protect themselves from immune response? |
convert fibrinogen to fibrin which forms a clot |
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Where does the puss come from? |
destroyed white blood cells |
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tatoo staphy infecct requires lengthy treatment |
neato |
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Where do peptic ulcer bact live? |
in mucous layer right near stomach |
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urease secretion leads to what product? purpose? |
ammonia neutralizes stomach acids near bact |
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what does the H. pylori ulcer breath test utilize? how does it work?* |
laballed urea, + urease ---> CO2 (13) + ammonia |
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Gonorrhea are gram ____, betaproteobacteria and cannot survive _______ |
- away from mucoid membranes |
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M and F symptoms of gonorrhea? |
F may be asympto --> lead to pelvic infalmm M pussy discharge |
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Thayer-Martin is used to detect? |
gram - dipplococci |
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What's neat about cell morphology of gonorrhea? |
polymorphic nucleated leukocytes |
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Can chlamydia survive well on surfaces? |
No, obligate intracell parasite |
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Gram- non-proteobact spirochete obligate intracell parastie Sounds like? |
syphilis |
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Why must syphilis import ATP? |
has glycolytic enz lacks TCA |
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what's nice about syphilis treatment? |
penicilin highly effective, no AB rest |
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What does syph do to body? |
produces chancres, can progess to attack CNS and cardiovasc |
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what do "safety pins" have to do with yersinia pestis? |
staining descr |
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How can plague be spread? |
infected flea, or direct contact with inf ani or hum or inhalation |
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What are buboes? |
enlarged lymph nodes |
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What does tetanus cause? how? |
paralysis release neurotoxin that prevents release of neurotrans into synaptic cleft. interferes with synaptic vessel fusion |
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How does cholera infection begin? |
adheres to intestin cells and releases AB exotoxin |
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food inf vs food poision? |
bact vs toxin |
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This type of E.Coli uses a type III secre sys to form pedastil for adheres, (2 types ) |
EHEC and EPEC |
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What is EIHC equiv to? |
shigella |
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What does EHEC do to intest epi cells? |
can break them down |
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are penicilins toxic to host? |
nope |
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How does penicilin inhib PPG synth? |
inhibs PPGase active site suicide inhib |
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What spectrum are cephalosporins? mech? |
Broad spec same as pencilins |
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which drug used to be drug of last resort? |
vancomycin |
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aminoglycoside mode of actin? |
protein synth inhib. binds ribo 30S |
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macrolides mech? |
block path of nascent peptide |
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tetracyclines |
prevent tRNA from bindinf ribo |
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how do sulfa drugs work? |
analog to precursor of folic acid synth |
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______ inhibs DNA dygrase and DNA topoisomerase ? |
quinolones |
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blocks channel wich DNA-RNA duplex must pass = ? |
rifamycins |
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tightly binds dsDNA, inhib transcr = ? |
actinomycin D |
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are natural killer cells phagocytitic? |
yes |
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What is pH of colon? |
near phys |
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What is the function for hematopoetic stem cells? |
progenitor for all blood cells |
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Topic 7 immunology |
>>>>>>>>> |
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_____ cells function in innate and adaptive immune resp |
white blood |
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what is the role of cytokines and chemokines on stem cells? |
influences differentiation |
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these cells develop into antigen presenting cells? |
monocytes |
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these cells release toxins to kill target cells? |
granulocytes |
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what type of immune resp are lymphocytes involved with? |
adaptive |
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What do T cells do? |
the recognize (with TC recept) MHC1 and MHCII peptides being presented by monocytes |
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What cell produces AB ? |
B cell and plasma cells |
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what is main def mech of innate response? |
phagocytosis |
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what are the 3 main functions of adaptive immun? |
recog non self respond non self remember |
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humoral mediated refers to? |
AB |
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what are immunogens? |
substances that induce immune resp |
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What is purpose of MHC? |
MHC AB bind antigen and present for TCR |
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what two things do natural killer NK, cells bind? |
MHC I on healthy cells - no resp Stress protein on diseased cell - resp |
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What is resp of NK-Stress prot- Cell intrxn? |
release granules containing Enz that induce apoptosis granzymes and perforins |
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What doe Th1-Antigen-MHCII-Macrophage intrxn result in? |
cytokine release, increas phagocytosis, increase inflamm |
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What does Th2 -B cell result in? |
Memory formation - ABs |
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Can B cell change which AB are expressed? |
yes |
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what are epitopes |
distinct portiion that binds AB of TCR |
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what gets elim during clonal selection? |
self-recog B cells |
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what does the complement refer to and what does it do? |
collection of heat-labile proteins in blood plasma, immune resp - differs e.g. inflam, incr phago ==death of foreign invader |
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what does opsonization allow? |
take up of cells that have been activated |
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in classical pathway, ______ activates complement |
specific binding AB-Ag |
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why Mannose binding - lectin pathway? MB -lectin |
b/c mannose major comp of bact cell wall and some virus envelopes |
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what activates alternative pathway? |
some and fungi with repetitive str e.g. LPS, PAMPS |
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What does MAC do ? |
forms pores in plasma membrane or outer membrane |
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What type microbe does MAC effect? |
not gram+ and fungi - no target membrane so gram - |
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interleukines are produced by ____ ? |
one leuk to act on another |
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interferons are produced in resp to ___ |
viral inf |
