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31 Cards in this Set
- Front
- Back
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size of microbes |
pollen, lymphocytes, rbc, yeast, e.coli, staphylococcus |
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gram positive cell wall |
thick peptidoglycan lipoteichoic acid mycolic acid- waxy (acid fast) |
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gram negative cell wall |
thin peptidoglycan LPS lipid A porins |
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what are cell walls composed of? |
N-acetylmurmic acid and N-acetylglucosamine glycosidic bonds lateral and peptide bonds vertical |
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components of bacteria |
flagella fimbriae-filaments attach to other cells pili- sex pili for conjugation capsule-attached to cell wall, extramural polymer slime layer-loose |
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carbon |
50% of dry weight |
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oxygen |
obligate facultative eg an: e.coli A: lactobacilli microaerophiles eg H pylori |
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nitrogen |
14% dry weight (g) 79% N2 fixation, dinitrogenase, dinitrogenase reductase |
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p s k mg ca na |
synthesis of nucleic acids and phospholipids structural role in aa and vitamins needed by all stability of ribosomes membranes and nucleic ac. cell wall stability growth |
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binary fission |
1. replicate genetic material 2. cell elongation 3. formation of cell wall and membrane 4. cell separates |
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cultures |
defined- know contents complex- roughly know contents transport- buffered liquid, blood urine saliva anaerobic- obligate anaerobes stab/reducing differential- blood agar, B(s. pyogenes) A(s. pnuemonia) Y(e. faecalis) selective- favours one |
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categories |
1. gram -ve eubac with cell walls: 16 groups eg. chlamydia 2. gram +ve eubac with cell walls: 18 groups eg. rods, bacilli, mycobacteria 3. eubac without cell walls: fac. ob. anaerobes
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endogenous and exogenous |
endo: GI, genital and skin exo: direct, food, air, water, vertical |
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immune defence: |
immunocompromised: break host barriers IS fail eg HIV immunosuppress eg anti cancer |
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virulence factors: |
adhesin: gram +ve: MSCRAMM protein A gram -ve: fimbriae |
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exotoxins and endotoxins: |
exo: cytolytic- rbc, ogliomeric rings punch hole AB- protein synthesis inhibitor
endo: when cell lysed, secreted living parts eg toxic shock and haemorrhage |
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physical control |
heat sterilisation: autoclave 121c 15lbin 10-15min filter sterilisation: fluids |
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chemical control: |
cell walls, cell membrane, proteins and DNA alcohols, aldehydes and halogens |
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antibiotic control: |
semi synthetic: post fermentation then chemically modified synthetic: chemically produced ideal- selective toxicity, long shelf life, non toxic to host, slow resistance |
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antivirals: |
nucleoside analogs- AZT NRTI-HIV NNRTI- inhibit RT by direct binding protease inhibitors- bind to AS of viral protease |
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antiflu: |
adamantanes inhibit ion flux in influenza inhibit viral uncoating inhibit viral release from cells
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interferons and antifungals |
prevent viral multiplication egosterols- distrupt cell memb
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characteristics of fungi |
decomposers: digest and recycle saprobes parasites when digest living matter |
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classification of fungi |
zygomycota, ascomycota, basidomycota |
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sexual reproduction of fungi |
hypae (filaments septate, aseptate) fusion of hypaes fusion of nuclei meiosis |
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structure of fungi: |
non reproductive= thallus yeast= bud
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cell wall of fungi |
chitin microfibrillar bundles N-acetylglucosamine 80-90% polysaccharides |
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pathogenic fungi
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fungal infection by inhalation |
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true pathogens |
4- blastomyces dermitidis coccidioides immitis histoplasma capsulatum paracoccidioides brasiliensis
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clinical aspects of fungi |
fungal infections: superficial, cutaneous, subcutaneous, systemic toxicoses: aflotoxins by aspergillus allergies: inhalation of spores |
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ergot alkaloids: |
stimulate labour contractions migrains erogtism: diarrhoea, headaches, vomiting, dry gangrene |
