Microbiology-2

1% and significant b/c 99% are unknown to biologists and knowlege is limitted

polysacharide derived from marine alga, and used as thickener in foods

• few microbes degrade agar, so it remains solid.
• liquifies at 100 degrees C (boiling point of water) and remains liquid until 40 degrees C.

free of living organisms

procedure to minimize unintentional introduction of microorganism

• -10⁰ celcius to 20⁰ celcius
• optimum 15⁰

• 0⁰ celcius to 30⁰ celcius
• optimum 25⁰

• 10⁰ to 50⁰ celcius
• optimum 25⁰

• 40⁰ celcius to 70⁰ celcius
• optimum 55⁰

• 65⁰ celcius to 110⁰ celcius
• optimum 80⁰

• protien denatures
• membrane fluidity

• amt of pressure in concentration of solute in a soln.
• example---> water goes where increased salt/sugar is so pressure pushes more water in that direction to dilute it.

high salt/sugar draw water out of cells and rpevent growth.

growth- needed for all living cells

protien synthesis

• synthesis of DNA/RNA
• from amino group of amino acids of protiens

• trace elements = cofactors
• cofactor are inorganic particles that are required for the fxn of other elements.

organism require oxygen to live

organism that continue to grow in absence of oxygen

organism unable to use oxygen for reactions needing energy.

organism taht cant use oxygen for growth, but tolerate it

organism that require oxygen (aerobic)

• lag phase- prepare for population growth, but no increase in population (little to no cell division)
• log phase- logarithmic/exponential increase in population as cells begin to divide
• stationary phase- equilibrium (death = # of cells produced)
• death phase- population decrease at logarithmic rate. number of deaths is greater then new cells formed.

mixed results.

communities of microbes reside in matrix made up of polysaccharide that contain DNA adn protien

microbial contamination

absence of significant contamination

destruction of all forms of microbial life, including endospores with possible exeption of prion

heat tx to kill endospores of botulisum in canned food

destruction of vegatative pathogens

destruction of vegatative pathogens on livign tissues

removal of microbes from limitted area, such as skin around injection site

tx intended to lower microbe count on eating utensils

death of microbe

inhibit growth/multiplication of bacteria

hospital acquired infection r/t patient vulnerability/low immune system and invasive procedures done

• aseptic technique
• handle contamination careful
• insist of frequent and good hand washing

• r/t heat resistance adn is the time in minutes in which 90% if bacteria will be killed at given temp.
• measurement---> 1 log decrease = 90% population killed

• critical items puncture tissues
• examples: needle, stitch, scalpel, knife, razor

• come in contact with mucous membranes
• examples: oral thermometer, foley cath, nasal spray, inhaler, speculum

• come into contact with unbroken skin
• examples: stethoscope, bp cuff, pulse ox, sun tan bed surface, stop watch

• silver(Ag)
• copper (Cu)
• mercury (Hg)

• organic acid
• sorbic acid, benzoic acid, calcium propionate
• nitrates
• antibiotics
• aldehyde
• gaseous sterilant
• peroxygens

inhibit metabolism, control mold and bacteria

1910 discovered salvarasan, arsenic compound. came up with using chemicals to tx infection

1928 left lab dirty adn mold grew on open petri dish, lead to discovery of penicillin, which led to first clinical trials

1932 discovered sulfa drug effective for sex transmitted disease

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

Mefloquine

ketoconazole

• niclosamide (tape worm)
• praziquantel (flukes)

acyclovir

penicillin G

isoniazid

streptomycin

tetracycline (most broad spectrum)

Inhibit cell wall synthesis

inhibit cell wall synthesis as penecillin but formed slightly different which makes more effective agains more gram (-) bacteria then penecillin

only tx still works for MRSA

• Methicillin resisistant Staphylococcus Aureus that is resistnat to antibiotic methicillin adn most other antibiotics.
• IV vancomycin is only tx left that is still effective

• 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

• lysogenic- cell replicates and host cell remains alive
• lytic- ends with lysis and death of host cell

• family names end in - viridae
• genus name end in- virus
• common name used for species
• subspecies designated by number

• 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.

• 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

• 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)

• attachment: virus attach to cell membrane
• penetration: endocytosis/fusion
• uncoating: viral or host enzyme
• biosynthesis: prodution of viral genetic material/protiens
• maturation: viral particle assembled
• release: budding (enveloped) or cell lysis

• 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

• 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

equilibrium virus within host and doesnt' produce disease for long periods of time (herpes virus)

chronic viral infections that occur gradual over time (fatal)

• masadenovirus (resp infect in hman/tumor in animal)
• paillomavirus (human warts)

• poxviridae (small poz/vaccinia virus)
• herpesviridae (chicken pox/shingle/fever blister)
• hepadnaviridae (hep B)

• parvoviridae
• human parvovirus

• picornaviridae (enterovirus- polio/coxsackie)(rhinovirus)
• caliciviridea (hep A/norovirus)

• togaviridae- (equine encephalitis/rubella)
• flavaviridae- (west nile/yellow fever)
• coronaviridae- (cold/SARS)

infectious protien inherited adn transmitted by ingestion, transplant adn invasive procedure

• freezing- still can grow/kills sample as ice crystal can rip apart cells d/t water in it
• lyophiliztion- freeze drying is best mode to store pure culture as it takes out water adn results in powder
• slants- dry out if put in incubator

introduce microbe into medium

microbes growing in/on medium

encourage growth of specific microbe by isolation with specific characteristics from heterogenous population

• # of microbes
• environment
• time of exposure
• microbial charateristic

• alter membrane permeability
• damage protiens
• damage nucliec acid

• boiling- fast, cheap reliable (doesnt kill endospores)
• pasterization- decrese number of microbes
• pressureized steam- achieve temp above 100 degrees celcius to destroy endospore (autoclave)
• dry heat (open flame)- high temp for long length

damage DNA

plasmolyusis

prevent metabolism

degerming

sanitizing

• bactericidal
• denature protiens
• disrupt plasma membrane

• chlorine (fair)
• glutaraldehyde (fair)

• phenolic (good)
• chlorine (fair)
• alcohol (good)
• glutaraldehyde (good)

• DNA/or RNA
• protien coat
• some enclosed in envelope
• some spiked
• only infect specific type of cells in 1 host

• virus particle
• capsid is protien coat surround nucleic acid
• capsid made up of individual protien capsomers
• virion particle is protien, nuclieic acid (nucleocapsid)
• non enveloped virus = naked

• helical- long rod looking
• polyhedral- 20 triangle faces with 12 corners
• complex- combination of above

inject RNA to make DNA and back to RNA (backwards)

• CJD
• sheep scrapie
• mad cow disease
• kuru

• chicken pox, human to human, respiratory droplets, skin lesions start on torso and spread to arms/legs
• tx- acyclovir

• Mono, shed in oral secretions of asymtomatic adult
• fever, sore thraot, lymphadenopathy
• tx- rest , fluid NO ANTIBIOTIC

• human infect via aerosolized rodent saliva or urine
• mild fever, follow by acute resp distress syndrome
• to tx

• severe acute resp syndrome
• srpead by aerosolized droplets
• fever, follow by 3-4 days of dry cough, trouble breathing
• chest xray to confirm
• tx- supportive care, prevention

• spread by aerosolized resp secretions
• high fever, head ache, myalgia, rhinorrhea, uncomfortable night sweat, ache,
• infect resp epithelium and kill host cell as it replicates.

• resp secretions from another infect person (inhalation/contact with infect object)
• virus kills resp mucosa cells
• tx- symmetrel, relenza, tamiflu
• 2 forms-( low patho)- undetected with mild s/s (high patho) spread rapid
• jumped species and gone from bird to human
• little to no immune protection
• s/s- fever, cough, sore throat, muscle ache, (serious) eye infection, pneumonia, resp distress

• small group of virus (orthomyxovirus/influenza)
• surface of virus covered with priotien (heamagglutinnin and neuraminidase)
• H protien attaches
• N protien let virus get out of infected cell (cant reproduce without H and N protien)

• influenza A from pig
• pig got 2 pig flu/1 human flu/1 bird flu all at same time
• s/s- regular flu but with GI s/s and more severe----> fatigue, headache, sore throat, nasal congest, vomit, diarrhea, nausea
• transmit from cough/sneeze and by touch
• tx- rest , fluid, manage fever, resistant to antiviral drug

• rhinovirus 50%
• coronovirus 15-20 %
• tx- vaccine ineffective

• spred by contact with infected skin or mucous membrane
• HSV1- oral
• HSV2- genital
• tx- acyclovir
• virus replicate in epithelium adn infect nerve ending

• poliovirus transmited by ingestion
• s/s- sore throat, nausea
• attacks brain stem and cant control body movement
• tx- vaccine prevention

• rhabdovirus
• animal bite transmission
• infect skeletal muslce then brain cell causing encephalitis
• s/s- msucle spasm of mouth/throuat, hydrophobia
• tx- (post) vaccine and immunoglobulin (pre) inject of human diploid cells vaccine
• types- (furious rabies) animal hightly exciteable (paralytic)- animal unaware of surrounding

• severe fatal disease
• animal borne (bats)
• spread by body fluid /body fluid contact
• s/s- fev er, headache, muscle and joint pain, sore throuat, weakness, diarrhea, vomit, stomach pain, rash , red eyes, hiccups, internal /external bleed, (bleed out)
• tx- fluid, electrolyte, oxygen, bp, prevent complications

• human papillovirus
• more then 150 strains
• 30 sexually transmitted
• 15 classified as high risk
• some cause abnormal paps
• transmission- genital contact, carriers unaware, can pass to baby
• link to cervical cancer
• vaccine- gardisiland 98 % effective for male and female