examples: stethoscope, bp cuff, pulse ox, sun tan bed surface, stop watch
3 types of heavy metal that have antimicrobial action?
types of food preservation?
sorbic acid, benzoic acid, calcium propionate
why calcium proprionate is used as food preservative ?
inhibit metabolism, control mold and bacteria
contributions of paul erlich?
1910 discovered salvarasan, arsenic compound. came up with using chemicals to tx infection
contribution of alexander fleming?
1928 left lab dirty adn mold grew on open petri dish, lead to discovery of penicillin, which led to first clinical trials
contribution of gerhard domagk?
1932 discovered sulfa drug effective for sex transmitted disease
contribution of ernst chain/howard florey?
1941 penicillin purified and avail after WW 2
any chemical or drug used to treat disease
interfere with growth of microbes within host
substance produced by microorganism that in sm amt inhibit another microorganism
drug that kills harmful microbe without damage of host
drug used to tx protozoa or malaria?
drug used to tx fungi
drug used to tx helminth?
niclosamide (tape worm)
drug used for tx of virus?
drug to tx gram (+) bacteria?
drug to tx mycobacterium ONLY? (TB)
drug to tx mycobacterium AND gram (-) bacteria?
drug to tx gram (-) and gram (+) bacteria AND Chlamydia/Rickettsia?
tetracycline (most broad spectrum)
how penecillin works?
Inhibit cell wall synthesis
how cephalosporin effect microbes?
inhibit cell wall synthesis as penecillin but formed slightly different which makes more effective agains more gram (-) bacteria then penecillin
why vancomycin important?
only tx still works for MRSA
what is MRSA and what is tx?
Methicillin resisistant Staphylococcus Aureus that is resistnat to antibiotic methicillin adn most other antibiotics.
IV vancomycin is only tx left that is still effective
how drug resistance develop?
mutations can lead to resistance
misuse of antibiotic
therapeutic effect of 2 drug given together is greater then if given either drug alone
simultaeous use of 2 drugs has less effect then if either drug taken alone
antibiotic that is bactericidal AND broad spectrum of activity
complementary DNA or peptide nucleic acid that bind to pathogens gens and prevent transcription
virus that infects bacterial cells
submicroscopic, parasitic, filterable agent consist of nucliec acid surround by protien coat
complete fully developed viral particle
2 ways virus attach and infect cells?
lysogenic- cell replicates and host cell remains alive
lytic- ends with lysis and death of host cell
viral taxonomy rules?
family names end in - viridae
genus name end in- virus
common name used for species
subspecies designated by number
2 ways virus grown in lab?
embryonated egg- hole drilled in shell adn virus injected in flud of egg. viral growth seen by death of embryo, embryo cell damage or formation of pocks/lesions on egg membranes
cell culture- treat slice of animal tissue with enzymes that seperate individual cells. these cells suspended in soln adn normal cells will adhere to glass/plastic container adn virus will infect monolayer causing celsl to deteriorate as they multiply.
ways virus are identified?
cytopathic effect- visible effect of viral infection (s/s of pt)
serological tests- virus detected and identified by its reaction with antibiotics by using specific testing
stages of bacteriophage multiplication?
attachment: phage attach by tail fiber
penetration: phage lysozyme opens cell wall and tail fibers contract and force tail core and DNA into cell
biosynthesis: production of DNA and protien
maturation: assembly of phage particle
release: phage lysozyme breaks cell wall (lysis)
stages of animal virus multiplication?
attachment: virus attach to cell membrane
uncoating: viral or host enzyme
biosynthesis: prodution of viral genetic material/protiens
maturation: viral particle assembled
release: budding (enveloped) or cell lysis
Lytic cycle in detail
attachment: chance collision between phage particle and bacteria and attachment site on virus attaches to complementary receptor site on bacteria
penetration: after attachment, bacteriophage injects DNA intio bacteria. the tail releases an enzyme which breaks down a portion of bacterial cell wall. the tail contracts and core is driven through cell wall.
biosynthesis: DNA reaches cytoplasm of host cell and biosynthesis of viral nucliec acid and protien occurs. host protien synthesis stops. Phage uses host cell to make many copies of DNA. biosynthesis of viral protien then begins and RNA transcribed in cell as mRNA.
maturation: bacteria DNA and capsid assembled into complete virion. this happens simultaneously eliminating need for nonstructural genes and gene product. the phage head/tail are seperated from protien subunit and head filled with DNA and attached to tail
release: realease from host cell. plasma membrane breaks open (lysis) and lysozyme causes bacteria cell wall to break down and release from host cell. it infects other susceptible cells and then multiplies with those cells
lysogenic cycle in detail
attachment: phage attaches to host cell and injects DNA
penetration: phage DNA circulizes adn enters lytic cycle or lysogenic cycle. the original linear phage DNA forms circle adn can multiply adn be transcribed leading to production of new phage adn cell lysis (lytic cycle)
in lysogenic cycle: circle can recombine adn become part of circular bacterial DNA (lysogenic cycle) the inserted DNA how are repressed by 2 repressor protien. they stop transcription of all other phage genes by binding to operators.
every time host cells machinery replicates bacteria chromosome also replicates prophage DNA. (remains latent in progeny cells)
in some cases: spontaneous event/action of UV light/chemicals cause popping out of phage DNA and initiation of lytic cycle
latent viral infection
equilibrium virus within host and doesnt' produce disease for long periods of time (herpes virus)
persistant viral infections?
chronic viral infections that occur gradual over time (fatal)
double strand DNA non envelope virus?
masadenovirus (resp infect in hman/tumor in animal)