bacteria pt 2 Flashcards
carbon source: organic
energy source: oxidation of organic compounds
- heterotrophic
carbon source: CO2
energy source: oxidation of inorganic compounds
- autotrophic/chemolithotrophic
carbon source: CO2
energy source: oxidation of organic compounds
- autotrophic chemoorganotrophic
carbon source:CO2
energy source: sunlight
- photosynthetic/photolithotropic
- cyanobacteria
- photoorganotropic
- bacteria that use glucose, lactose or mannitol
- s. aureus
- enterococcus
- enterobacter
- bacteria that undergo fermentation
- lactobacillus
- candida albicans (ethonal)
- Enterobacter/e. coli (2,3 butanediol)
aerobic respiration, final electron acceptor is..
O2
anaerobic respiration, final electron acceptor is…
NO3, CO2
total net ATP yield of aerobic respiration
36
total net ATP yield of anaerobic respiration
3-34
total net ATP yield of fermentation
2
- grouping of bacteria based on metabolism rxns and carbon sources
biochemical testing
- tests the ability to produce acidic metabolic products by oxidation or fementation, from a range of carbs
- color based
- can identify most groups of bacteria
- uses pyruvate
carbohydrate break down
- test that uses catalase converts H202 to water and oxygen
- produces gas bubbles
- particularly useful to differentiate staphylococci positive from staphylococci neg
- enzyme presence or not
catalase production
- test that uses coagulase to convertfibrinogen to fibrin clot
- media solidifies and formation of a clot
- differentiate s. aureus from less pathogenic staph
coagulase
- tests that uses urease to convert urea to 2 molecules of NH3 and molecule of CO2
- increases in medium pH
- p. vulgaris and entericrods
urease production
- tests for bacteria using different mechanisms for nitrate reduction
- detection of nitrite or N2 gas
- standard urinalysis test to detect presence of UTI
nitrate reduction
- tests the ability of some bacteria to produce H2S from amino acids or other sulfur containing compounds
- black color of the sulfide salts formed w heavy metals such as iron added to the plate
- distinguishes between the gram negative rods
hydrogen sulfide
when using a catalase test, strep tests:
and
staph tests:
- negative
- positive
- biochemical aspects of antibiotic resistance
alters substrates or enzymes
- inactivation (via hydrolysis, group transfer, redox)
- target modification (peptidoglycan alters, protein structure interference, DNA synthesis interference)
efflux pumps and OM permeability changes
- target bypass
- genetic aspects of antibiotic resistance
- mutations
- horizontal gene transfer via plasmind, transposons, integrons
vertical transfer
- transfer to daughter cells
- chromosomal means
horizontal transfer
- 2 adult cells sharing genetic infor w each other
- aka lateral
- by extrachromosomal techniques
- mobile DNA that moves by cell to cell contact w transfer of plasmids or chromosomal genetic material
- conjugation
- mobile DNA that moves by plasmid DNA entering the cell via bacteriophage infection
- transduction
- mobile DNA that movies via uptake of enviromental DNA into bacterial cell and incorporation into genome
transformation
- spontaneous mutations
- rarely leads to complete resitance but if mutationi s stable it results in rapid increase in # of mutants
- chromosomal mediated resitance
- clinical importance, especially for gram neg rods (50%) of GI bacteria
- mediates multi-drug resistance
- high rate of transfer between cells
- plasmid resistance (conjugation)
- transduction where phage mediated transfer of resistance genes, clinically significant for Gram pos staph
- transformation uptake of resistance transposon by a drug sensitive bacterium after lysis of a resistant bacteria, much less clinical significance
- transposon mediated resistance
aminoglycosides inactivate drugs via…
- phosphorylation
- adenylation
- acetylation
macrolides inactive drugs via
- erythromycin esterase
2nd easiest mechanism of resistance to antibiotics involving gram neg porins and transport proteins (tetracyclines, quinolones, aminoglycosides)
- alteration of membrane permeability
1st easiest, most common mechanism of resistance to antibiotics by removal of the drug used by tetracyclines, quinolones and macrolides
- efflux pumps
