microbial nutrition, growth, measurement, and control

MICROBIAL NUTRITION,

GROWTH, MEASUREMENT, AND CONTROL

RESOURCES ON LINE• http://www.bact.wisc.edu/Microtextbook/i

ndex

• AN ONLINE TEXTBOOK

• http://www.bact.wisc.edu/bact100/KimballLinks.html

• http://science.nhmccd.edu/Biol/microbio.html

• http://science.nhmccd.edu/BioL/animatio.htm

MICROBIAL NUTRITION

MICROBIAL HABITATS

• OCEANS

• ANTARCTIC ICE CAP

• VERTEBRATE AND INVERTEBRATE GUT

• JAMS, JELLIES, PICKLES

• VIRTUALLY EVERYWHERE

MICROBIAL NUTRITION

• ORGANISMS MUST GET FOOD FROM ENVIRONMENT

• WIDE VARIETY OF NUTRITIONAL STRATEGIES

• http://www.mansfield.ohio-state.edu/~sabedon/campbl27.htm#photoheterotroph

NUTRITIONAL TYPES• PHOTOAUTOTROPHS• CHEMOAUTOTROPHS• PHOTOHETEROTROPHS• CHEMOHETEROTROPHS• http://72.14.203.104/search?

q=cache:EkMmMJD4ZtIJ:rcw.raiuniversity.edu/biotechnology/BTechbiotech/microbesandus/lecture-notes/lecture-10.pdf+microbial+nutrition+chemoheterotroph+photoheterotroph+photoautotroph&hl=en&gl=us&ct=clnk&cd=5

• http://www.sinauer.com/perry/Perry_SG_05.pdf

PHOTOAUTOTROPHS

• LIGHT AS ENERGY SOURCE• CARBON DIOXIDE AS CARBON

SOURCE• H2O, H2, OR H2S AS ELECTRON DONOR• http://72.14.203.104/search?

q=cache:sclpkxyy_VMJ:www.homepage.montana.edu/~umbls/mb301/lecquiz2key.pdf+photoautotroph&hl=en&gl=us&ct=clnk&cd=26

OXYGENIC PHOTOSYNTHESIZERS

• OXYGEN GIVEN OFF• GENERATED FROM WATER• PHOTOSYSTEM II PRESENT• CYANOBACTERIA, ALGAE, AND

GREEN PLANTS• http://72.14.203.104/search?

q=cache:3iUlq0IL7tsJ:meetings.copernicus.org/egu2005/download/EGU05-J-11198-1.pdf+oxygenic+photosynthesizer&hl=en&gl=us&ct=clnk&cd=5

ANOXYGENIC PHOTOSYNTHESIZERS

• DO NOT USE WATER• USE H2S, H2 , SULFUR OR SULFIDE• USE BACTERIOCHLOROPHYLLS• http://72.14.203.104/search?

q=cache:3iUlq0IL7tsJ:meetings.copernicus.org/egu2005/download/EGU05-J-11198-1.pdf+anoxygenic+photosynthesizer&hl=en&gl=us&ct=clnk&cd=2

PHOTOHETEROTROPHS

• LIGHT AS ENERGY SOURCE

• NEED ORGANIC COMPOUNDS OR HYDROGEN GAS AS ELECTRON DONOR

• GREEN NONSULFUR BACTERIA

• PURPLE NONSULFUR BACTERIA

• http://www.sinauer.com/perry/MicrobialLife05.pdf

CHEMOAUTOTROPHS

• REDUCED INORGANIC MOLECULES ACT AS CARBON AND ENERGY SOURCES

• INORGANIC MOLECULE FINAL ELECTRON ACCEPTOR

• CARBON DIOXIDE ACTS AS CARBON SOURCE

• ENERGY OBTAINED FROM H2, NH3, H2S, ELEMENTAL SULFUR, NO2 and Fe+2.

• http://uweb.cas.usf.edu/~kscott/chemoautotrophy.htmhttp://highered.mcgraw-hill.com/sites/0078664276/student_view0/unit1/chapter4/check_challenge_quiz_3.html

CHEMOHETEROTROPHS

• USE PREFORMED CARBON COMPOUNDS AS ENERGY AND CARBON SOURCE

• USUALLY THE SAME ORGANIC COMPOUND

• FUNGI, ANIMALS, PROTOZOA AND MOST BACTERIA

• http://www.bact.wisc.edu/bact100/origins.html

SAPROPHYTE VS PARASITE

• SAPROPHYTE USES DEAD ORGANIC MATTER

• PARASITE USES LIVING HOST

MICROBIAL NUTRITION

• http://www.mansfield.ohio-state.edu/~sabedon//biol2015.htm

• http://www.agen.ufl.edu/~chyn/age4660/lect/lect_02/lect_02.htm

MACRONUTRIENTS

• NEEDED IN LARGE AMOUNTS• CARBON• HYDROGEN• OXYGEN• NITROGEN• PHOSPHORUS• SULFUR• http://www.biologie.uni-hamburg.de/b-online/

library/micro229/terry/229sp00/lectures/nutrition.html

CARBON

• FORMS CARBON SKELETON OF ORGANIC MOLECULES

• CARBON DIOXIDE MOST COMMON SOURCE

OXYGEN

• FOUND IN MOST ORGANIC MOLECULES

• ATMOSPHERIC

• CHEMICALLY BOUND

• OXYGENASES

TOXIC OXYGEN COMPOUNDS

• OXYGEN ITSELF• HYDROGEN PEROXIDE• SUPEROXIDE RADICAL• HYDROXYL RADICAL• http://www.sigmaaldrich.com/

Area_of_Interest/Biochemicals/Enzyme_Explorer/Cell_Signaling_Enzymes/Superoxide_Dismutase.html

ENZYMES THAT DETOXIFY FREE RADICALS

• SUPEROXIDE DISMUTASE

• CATALASE• PEROXIDASE

OXYGEN RELATIONSHIPS

• OBLIGATE AEROBES• FACULATIVE ANAEROBES OR

FACULATIVE AEROBES• MICROAEROPHILES• AEROTOLERANT ANAEROBES• OBLIGATE ANAEROBES• http://www.jlindquist.net/generalmicro/

dfthiognf.html

HYDROGEN

• FOUND IN ORGANIC MOLECULES

• CHEMIOSOMOSIS

• REDUCES CARBON DIOXIDE IN CALVIN CYCLE

PHOSPHORUS

• FOUND IN ATP

• PHOSPHOLIPIDS

NITROGEN

• COMPONENT OF NUCLEIC ACIDS

• COMPONENT OF PROTEINS

• COMPONENT OF COENZYMES

SULFUR

• COMPONENT OF ACETYL COA

• COMPONENT OF PROTEINS

• MOST MICROBES USE SULFATE

OTHER ELEMENTS USED BY MICROBES

• POTASSIUM

• MAGNESIUM

• IRON

• CALCIUM

IRON

• COMPONENT OF HEME GROUPS

• FERRIC AND FERROUS FORMS

• CHELATORS INCREASE ABSORPTION

MICROELEMENTS

• MOLYBEDNUM

• COBALT

• COPPER

• NICKEL

• MANGANESE

OTHER ELEMENTS USED BYA RELATIVE FEW ORGANISMS

• SELENIUM & TUNGSTEN– ARCHAEBACTERIA

• SODIUM AND CHLORIDE IONS– HALOPHILES

ACCESSORY GROWTH FACTORS

• VITAMINS

• FATTY ACIDS

• AMINO ACIDS

• PURINES AND PYRMIDINES

VITAMINS

• DIFFERENT ORGANISMS HAVE DIFFERENT VITAMIN NEEDS

• NEEDS CAN VARY WITH CONDITIONS

FATTY ACIDS

• SOME BACTERIA AND PROTOZOA NEED FATTY ACIDS

• MYCOPLASMAS NEED CHOLESTEROL OR OTHER STEROLS

AMINO ACIDS

• NEEDS VARY

• MUST INCORPORATE INTO MEDIA

PURINES AND PYRIMIDINES

• SOME MICROBES ARE UNABLE TO SYNTHESIZE THEIR OWN

• MUST BE INCLUDED IN MEDIAADENINE THYMINE

EUTROPHIC VS OLIGOTROPHIC ENVIRONMENTS

EUTROPHIC ENVIRONMENTS

• ABUNDANCE OF NUTRIENTS

• NO LIMITING FACTORS

• CULTURAL EUTROPHICATION

• http://www.umanitoba.ca/institutes/fisheries/eutro.html

SOURCES OF CULTURAL EUTROPHICATION

• MAN’S ACTIVITY INCREASES NUTRIENTS IN ENVIRONMENT– FARMING– SEWAGE

• INCREASE BIOLOGICAL OXYGEN DEMAND– BOD

OLIGOTROPHIC ENVIRONMENTS

• FEW NUTRIENTS• STREAMS • RIVERS • SOME SOILS

LABORATORY CULTURE

http://www.bact.wisc.edu/Microtextbook/index.php?

module=Book&func=displayarticle&art_id=26

NUTRIENT UPTAKE

• SPECIFIC• OFTEN MUST MOVE AGAINST

CONCENTRATION GRADIENT• http://users.rcn.com/jkimball.ma.ultranet/Bi

ologyPages/D/Diffusion.html#Facilitated_diffusion

• http://web.mit.edu/esgbio/www/cb/membranes/transport.html

TRANSPORTATION MECHANISMS

• DIFFUSION• OSMOSIS• FACILITATED

DIFFUSION• ACTIVE

TRANSPORT• GROUP

TRANSLOCATION

DIFFUSION

• SMALL NONPOLAR SUBSTANCES

• DOWN CONCENTRATION GRADIENT

• CARBON DIOXIDE• OXYGEN• CARBON DIOXIDE

• MOLECULES SPREAD FROM AREAS OF HIGH CONCENTRATIION, TO AREAS OF LOW CONCENTRATION

• . MOLECULES EVENTUALLY EVENOUT THROUGHOUT A SPACE - EQUILIBRIUM

• CONCENTRATION GRADIENT - A DIFFERENCE BETWEEN CONCENTRATIONS IN A SPACE

FACILITATED DIFFUSION

• PASSIVE PROCESS

• PERMEASES

• DOES NOT HAPPEN MUCH IN PROKARYOTES

• MORE IMPORTANT IN EUKARYOTES

• http://bio.winona.msus.edu/berg/ANIMTNS/FacDiff.htm

ACTIVE TRANSPORT

• MOVE MATERIALS AGAINST CONCENTRATION GRADIENT

• USES ENERGY TO POWER

• CARRIER MOLECULES

• ANTIPORT

• SYMPORT OR COTRANSPORT

SYMPORT OR COTRANSPORT

• http://bio.winona.msus.edu/berg/ANIMTNS/symport.htm

ANTIPORT

• http://bio.winona.msus.edu/berg/ANIMTNS/ANTIport.htm

• http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html

THE PRICE OF ACTIVE TRANSPORT

• ATP OR OTHER PHOSPHATE MOLECULES

• PROTON MOTIVE FORCE

GROUP TRANSLOCATION

• MOLECULES ARE MODIFIED AS THEY CROSS CELL MEMBRANE

• PHOSPHOPHENOLPYRUVATE: SUGAR PHOSPHOTRANSFERASE

• WIDESPREAD IN PROKARYOTES• VARIETY OF FORMS

http://www.cat.cc.md.us/courses/bio141/lecguide/unit1/prostruct/group.html

ENDOCYTOSIS VS EXOCYTOSIS

EUKARYOTIC MECHANISM

ENDOCYTOSIS

• MOVEMENT OF MATERIALS INTO THE CELL– PHAGOCYTOSIS = ‘CELL EATING’

• BY MACROPHAGES & WBCS• PARTICLE BINDS TO RECEPTOR PROTEIN• WHOLE BACTERIA OR VIRUSES ARE ENGULFED & LATER

DIGESTED

– PINOCYTOSIS = CELL DRINKING• NO RECEPTOR PROTEINS

– RECEPTOR-MEDIATED ENDOCYTOSIS = SELECTIVE INPUT

• MECHANISM BY WHICH HIV VIRUS ENTERS CELLS

Pinocytosis and Phagocytosis

• Pseudopods extend to form phagosome

• Lysosome joins it

• No pseudopods form• Nonselective drinking of extracellular

fluid

PINOCYTOSIS

PHAGOCYTOSIS

Receptor-Mediated Endocytosis• Mechanism for uptake of specific

substances -- ligands

• Desired substance binds to receptor protein in clathrin-coated pit region of cell membrane causing membrane to fold inward

• Vesicles become uncoated & combine with endosome

• Receptor proteins separate from ligands and return to surface

• Ligands are digested by lysosomal enzymes or transported across cell -- epithelial cell crossing accomplished

• http://cellbio.utmb.edu/cellbio/recend.htm#Menu

EXOCYTOSIS

• MOVEMENT OF MATERIALS OUT OF CELL

• ‘CELL VOMITING’• Vesicles form inside cell,

fuse to cell membrane

• Release their contents– digestive enzymes,

hormones, neurotransmitters or waste products

• replace cell membrane lost by endocytosis

http://bio.winona.msus.edu/berg/ANIMTNS/Secrtion.htm

IRON UPTAKE

• USED FOR CYTOCHROMES AND ENZYMES

• FERRIC IRON INSOLUBLE

• SIDEROPHORES

MEDIA USED IN LABORATORY CULTURE

http://www.life.umd.edu/classroom/bsci424/BSCI223WebSiteFiles/Chapter6.htm

CLASSIFICATION OF MEDIA

• PHYSICAL FORM

• CHEMICAL CHARACTERISTICS

• FUNCTIONAL TYPES

LIQUID MEDIA

• AQUEOUS FORMULATION• DOES NOT GEL OR

SOLIDIFY AT ROOM TEMP• FLOW FREELY• BROTHS• MILKS• NUTRIENT SOLUTIONS

SEMISOLID MEDIA

• SOLID AT ROOM TEMP• GELATINOUS TEXTURE• 0.3% TO 0.5% AGAR• USED TO RESTRICT

MOVEMENT OF MOTILE MICROBES, GROW MICROAEROPHILES OR ANAEROBES

• SIM AGAR• MOTILITY MEDIA

SOLID MEDIA

• PROVIDES FIRM SURFACE

• LIQUEFIABLE OR NONLIQUEFIABLE

• DISTINCT COLONIES FORM

LIQUEFIABLE SOLID MEDIA

• REVERSIBLE SOLID MEDIA

• THERMOPLASTIC SOLIDIFYING AGENT

• AGAR OR GELATIN

GELATIN WAS FIRST SOLIDIFYING AGENT

• DRAWBACKS• CAN BE LIQUID AT

ROOM TEMP• MANY MICROBES

DIGEST

BENEFITS OF AGAR-AGAR

• COMPLEX POLYSACCHARIDE

• SOLID AT ROOM TEMPERATURE

• LIQUEFIES AT 100 DEGREES C

• DOES NOT RESOLIDIFY UNTIL IT COOLS TO 42 DEGREES C

• CAN BE INOCULATED AND POURED IN LIQUID FORM

• MOLDABLE AND FLEXIBLE FRAMEWORK FOR MOISTURE AND NUTRIENTS

• NOT EASILY DIGESTED

NONLIQUEFIABLE SOLID MEDIA

• NOT THERMOPLASTIC

• RICE• POTATOE• MEAT• EGG MEDIA• SERUM MEDIA• LESS VERSATILE

CHEMICAL CONTENT OF MEDIA

• CHEMICALLY DEFINED OR SYNTHETIC

• NONSYNTHETIC OR EMPIRICAL MEDIA

FUNCTIONAL CATEGORIES

• GENERAL PURPOSE

• ENRICHED

• SELECTIVE

• ENRICHMENT MEDIA

GENERAL PURPOSE MEDIA

• GROW A BROAD SPECTRUM

• USUALLY NONSYNTHETIC

• NUTRIENT BROTH AND AGAR

• TRYPTIC SOY BROTH AND AGAR

• BLOOD AGAR

• BRAIN-HEART INFUSION AGAR

ENRICHED MEDIA

• SIMILAR TO GENERAL PURPOSE MEDIA

• ENRICHED WITH BLOOD, SERUM, HEMOGLOBIN, OR GROWTH FACTORS

• BLOOD AGAR

• THAYER MARTIN AGAR

SELECTIVE METHODS

• SELECTIVE ENRICHMENT

• SELECTIVE REPRESSION

SELECTIVE ENRICHMENT

• VARYING TEMPERATURE

• pH

• CHEMICAL ENVIRONMENT

ENRICHMENT MEDIA

• EXTREMELY SELECTIVE MEDIA

• FAVORS GROWTH OF PATHOGENS FOUND IN LOW NUMBERS

• SELENITE

• BRILLIANT GREEN

• POTASSIUM TELLURITE

SELECTIVE MEDIA

• HAS AGENT/S THAT INHIBITS GROWTH OF CERTAIN MICROBES

• SELECTS FOR GROWTH OF OTHERS

• IMPORTANT FOR IDENTIFICATION FROM SAMPLES

• MANNITOL SALT AGAR

• MacCONKEY AGAR

• EMB AGAR

SELECTIVE REPRESSION

• STOPS OR SLOWS THE THE GROWTH OF INTERFERING ORGANISMS

• TOXIC CHEMICALS

• TEMPERATURE

DIFFERENTIAL MEDIA

• EXPLOITS PHYSIOLOGICAL & OTHER CHARACTERISTICS TO DISTINGUISH COLONIES

• CONTAIN REAGENTS

• DO NOT NECESSARILY ENRICH OR REPRESS

• BLOOD AGAR

• EMB

DIFFERENTIAL MEDIA

• GROW SEVERAL TYPES OF MICROBES

• WILL HAVE VARYING APPEARANCES DUE TO AGENTS

EXAMPLES OF AGARS

EMB AGAR

MacCONKEY AGAR

MANNITOL SALT AGAR

ISOLATING PURE CULTURE

KOCH AND HIS PROCEDURES

KOCH’S POSTULATES

• ORGANISM SHOULD ALWAYS BE PRESENT IN ANIMALS WITH DISEASE

• NOT PRESENT IN ANIMALS THAT ARE HEALTHY

• MUST CULTIVATE ORGANISMS IN PURE CULTURE

• WHEN CULTURE INTRODUCED INTO HEALTHY ANIMAL SHOULD CAUSE DISEASE

• MUST BE REISOLATED FROM EXPERIMENTAL ANIMAL

PURE CULTURE TECHNIQUE

• SUCCESS DEPENDS ON HAVING ONLY ONE MICROBE IN CULTURE

• SOLID MEDIA ALLOWS FOR DEVELOPMENT OF SINGLE COLONIES

PETRI PLATES

STREAK PLATE

• DEVELOPED BY KOCH

• ASEPTIC TECHNIQUE

POUR PLATE METHOD

• SERIAL DILUTIONS INTO LIQUID AGAR

PRESERVATION OF MICROBES

• SUBCULTURING

• REFRIGERATION

• DESSICATION

• LYOPHILIZATION

ENVIRONMENTAL FACTORS AND GROWTH

EFFECTS OF TEMPERATURE

CARDINAL TEMPERATURES

• MINIMUM TEMPERATURE

• MAXIMUM TEMPERATURE

• OPTIMAL TEMPERATURE

MAXIMUM TEMPERATURE

• REFLECTS DENATURING OF PROTEINS AND ENZYMES

MINIMUM TEMPERATURE

• MAYBE DUE TO LOSS OF FLUIDITY IN CELL MEMBRANE

TEMPERATURE

• EFFECTS ALL RELATIONSHIPS IN CELL

• PSYCHROPHILES• MESOPHILES• THERMOPHILES

PSYCHROPHILES• BEST AT 15

DEGREES C OR LOWER

PSYCHROTROPHS

• ARE ALSO MESOTROPHS BEST GROWTH AT 20-30 DEGREES C– CAN GROW SLOWLY

AT LOW TEMPERATURES

– TOLERATE RATHERE THAN BENEFIT FROM THEM

• SPOIL FOOD IN FRIDGE– LISTERIA

MONOCYTOGENES

MESOPHILES

• MOST MICROBES ARE MESOPHILES

• HUMAN PATHOGENS ARE

THERMOPHILES

• HEAT LOVERS• ABOVE 55

DEGREES C• CAN GROW IN

BOILING WATER 100 DEGREE C

HYPERTHERMOPHILES

• GROW AT 90 DEGREES C OR HIGHER

• SOME HAVE MAXIMA ABOVE 100 DEGREES C

• DO NOT GROW WELL BELOW 55

ENVIRONMENTAL FACTORS AND GROWTH

ACIDITY AND ALKALINITY

PH AND MICROBIAL GROWTH

• MOST ORGANIMS HAVE PH RANGE

• MOST FALL WITHIN PH 5 - 9

• ACIDOPHILES• NEUTROPHILES• ALAKALOPHILES

ACIDOPHILES

• LOW PH OPTIMA

• FUNGI TEND TO BE MORE ACID TOLERANT THAN BACTERIA

• OBLIGATE ACIDOPHILIC BACTERIA THIOBACILLUS SULFOLOBUS THERMOPLASMA

IMPORTANCE OF HYDROGEN IONS TO CELL

MEMBRANE STABILITY• IN NEUTRAL PH CELL MEMBRANE

DISINTEGRATES

• CELL LYSES

ALKALIPHILES

• HIGH PH OPTIMA FOR GROWTH

• SODA LAKES & HIGH CARBONATE SOILS

• SOME ARE ALSO HALOPHILES

NEUTROPHILES

• MAJORITY OF MICROBES

• PH 6 - 8

HOW TO LIVE IN HIGH AND LOW PH ENVIRONMENTS

• INSIDE OF CELL MUST BE AT PH NEAR 7

• MEMBRANE MAY BE IMPERMEABLE TO H+ IONS

• MAY EXCHANGE IONS ACROSS MEMBRANE

• CELL WILL MOVE H+ ACROSS MEMBRANE TO KEEP PH STABLE

MAINTAINING PH IN THE LAB

• BUFFERS

• WORK OVER NARROW PH RANGE

ENVIRONMENTAL FACTORS AND GROWTH

WATER AVAILABILTY

OSMOSIS

• HIGH CONCENTRATION TO LOW CONCENTRATION

• ACROSS CELL MEMBRANE

• http://www.colorado.edu/eeb/web_resources/osmosis/

• http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm

POSITIVE WATER BALANCE

• WATER USUALLY DIFFUSES INTO CELLS– CAUSING LYSIS OR TURGOR PRESSURE

NEGATIVE WATER BALANCE

• WATER WILL MOVE OUT OF THE CELL

• CAUSING CRENATION OR PLASMOLYSIS

OSMOTIC EFFECTS IN HIGH SALT ENVIRNOMENTS

• SEA WATER --3% NA CL

HALOPHILES

• MILD HALOPHILES 1-6%

• MODERATE HALOPHILES 6-15%

• EXTREME HALOPHILES 15-30%

• HALOTOLERANT CAN TOLERATE BUT GROW BEST WITHOUT

EFFECTS OF HIGH SUGAR ENVIRONMENTS

• OSMOPHILES

EFFECTS OF LOW WATER (DRY) ENVIRONMENTS

• XEROPHILES

HOW DO MICROBES GROW IN AREAS WITH LOW WATER

• COMPATIBLE SOLUTES

• PROLINE

• BETAINE

• GLYCEROL

ENVIRONMENTAL FACTORS AND GROWTH

OXYGEN

TYPES OF MICROBES

• AEROBES

• MICROAEROPHILES

• FACULATIVE ANAEROBES OR AEROBES

• AEROTOLERANT ANAEROBES

• OBLIGATE ANAEROBES

TOXIC FORMS OF OXYGEN

• SINGLET OXYGEN 1O2

• SUPEROXIDE ANION 1O2-

• HYDROGEN PEROXIDE H2O2

• HYDROXYL RADICAL ·OH

• ALL ARE BYPRODUCTS OF RESPIRATION

SINGLET OXYGEN

• NORMAL MOLECULAR OXYGEN

• AT HIGHER ENERGY STATE• EXTREMELY REACTIVE

SUPEROXIDE ANION

• O2-

• HIGHLY REACTIVE• OXIDIZES ANY ORGANIC MOLECULE

PEROXIDES

• CAN DAMAGE CELL COMPONENTS• NOT AS TOXIC AS OTHERS

HYDROXYL RADICAL

• OXIDIZES ORGANIC SUBSTANCES• TRANSIENT• NOT A LOT MADE UNLESS EXPOSED TO IONIZING

RADIATION• SMALL AMOUNTS CAN BE MADE FROM

HYDROGEN PEROXIDE

ENZYMES THAT DESTROY TOXIC OXYGEN PRODUCTS

• CATALASE

• PEROXIDASE

• SUPEROXIDE DISMUTASE

ANAEROBIC MICROBES

• FREQUENTLY LACK MEANS TO DETOXIFY OXYGEN BY PRODUCTS

ENVIRONMENTAL FACTORS AND GROWTH

PRESSURE

PRESSURE RELATIONSHIPS

• MOST ORGANISMS LIVE AT 1 ATMOSPHERE PRESSURE

• BAROTLERANT• BAROPHILIC

MICROBIALGROWTH

MICROBIAL GROWTH

GROWTH OF POPULATIONS NOT INDIVIDUALS

DOUBLING TIME

• GENERATION TIME

• DEPENDS ON SPECIES

• DEPENDS ON GROWTH CHARACTERISTICS

• TELLS HOW FAST POPULATION IS GROWING

THE WAY WE GROW

• ENLARGE AND DIVIDE WHEN DOUBLED IN SIZE

• BINARY FISSION

• BUDDING

• BINARY FISSION AND MITOSIS

• MITOSIS AND CYTOKINESIS

EUKARYOTIC CELL DIVISION

• GO PHASE

• G1 PHASE

• S PHASE

• G2 PHASE

• M PHASEC PHASE

GO PHASE

• PRIMARY GROWTH PHASE OF CELL

• ENLARGEMENT

G1 PHASE

• CELL PREPARES FOR DNA REPLICATION

• PRODUCES ENZYMES

• PRODUCES NUCLEOTIDES

S PHASE

• SYNTHESIS PHASE• REPLICATION OF

GENOME OCCURS

G2 PHASE

• PRODUCES ORGANELLES FOR M PHASE

• STOCKPILES VITAL CELLULAR PRODUCTS

• CHROMOSOME BEGIN CONDENSING

M PHASE

• MITOSIS PHASE

• DIVIDES THE NUCLEUS INTO TWO DAUGHTER NUCLEI

• PROPHASE

• METAPHASE

• ANAPHASE

• TELOPHASE

PROPHASE

METAPHASE

ANAPHASE

TELOPHASE

C PHASE

• CYTOKINESIS PHASE

• DIVISION OF CYTOPLASM AND ORGANELLES INTO TWO DAUGHTER CELLS

CYTOKINESIS

BACTERIAL CELL DIVISION

BUDDING

BINARY FISSION

BUDDING

• YEAST LIKE PROCESS

• But no mitosis occurs

BINARY FISSION

• CHROMOSOMES DO NOT SHUT DOWN DURING DIVISION

• CELL MEMBRANE REPLACES MITOTIC SPINDLE

• PRODUCES TWO NEARLY EQUAL SIZED CELLS

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_2.html

PROCESSES INVOLVED

• CELL ELONGATION

• DNA REPLICATION

• CELL DIVISION

CELL ELONGATION

GRAM NEGATIVE BACTERIA

GRAM POSITIVE BACTERIA

DNA REPLICATION

• TIME TABLE CAN VARY

• MAY HAVE MULTIPLE REPLICATION FORKS

• MAY LEAD TO MULTIPLE CHROMOSOMES

CELL DIVISION

• USUALLY BEGINS AS INVAGINATION

• USUALLY AUTOLYSIS TO FORM TWO CELLS

• GET VARIETY OF ARRANGEMENTS

GRAM NEGATIVE BACTERIA

PLANES OF CELL DIVISION

VIABLE NONCULTURABLE CELLS

• HAVE ACTIVE METABOLISM

• CAN’T BE GROWN ON CONVENTIAL MEDIA

• VIBRIO CHOLERAE, LEGIONELLA PNEUMONIAE

EXPONENTIAL GROWTH

• POPULATION NUMBERS INCREASE BY A FACTOR OF TWO

TYPES OF GROWTH

SYNCHRONOUS VS ASYNCHRONOUS

GROWTH PHASES

• LAG PHASE• LOG PHASE• STATIONARY

PHASE• DEATH PHASE

HOW DO WE KNOW A CELL IS DEAD

• CANNOT CONTINUE CELLULAR REPAIR

• CANNOT REINITIATE GROWTH WHEN INTRODUCED TO NEW MEDIA

LABORATORY CULTURE METHODS

BATCH VS CONTINUOUS CULTURE

BATCH CULTURE

• USUALLY TYPE OF BACTERIAL GROWTH

• SHOWS NORMAL GROWTH CURVE

CONTINUOUS CULTURE

• CHEMOSTAT

COLONY GROWTH

• FORMS FROM SINGLE CELL

• DIFFERENT PHASES OF GROWTH IN DIFFERENT PARTS OF COLONY

MEASURING MICROBIAL GROWTH

DIRECT VS INDIRECT

VIABLE VS TOTAL

INDIRECT MEASUREMENTS

• MEASURE PROPERTIES OF POPULATION

• TURBIDITY

• DRY WEIGHT

• METABOLIC ACTIVITY

DIRECT MEASUREMENTS

• DIRECT MICROSCOPIC COUNT

• ELECTRONIC COUNT

• PLATE COUNT

• MOST PROBABLE NUMBER

VIABLE COUNT

• COUNTS LIVING CELLS

• PLATE COUNTS

• MOST PROBABLE NUMBER

• METABOLIC ACTIVITY

• FILTRATION

TOTAL COUNT

• TURBIDITY

• DRY WEIGHT

• DIRECT MICROSCOPIC COUNT

• DIRECT ELECTRONIC COUNT

TURBIDITY

• NUMBER IS PROPORTIONAL TO WEIGHT OF A SAMPLE

• SPECTROPHOTOMETER

USE OF THE SPECTROPHOTOMETER

• ESTIMATES MASS OF DENSE CULTURES

• CHARTS GROWTH COMPARED TO STANDARD GROWTH CURVE

• ADVANTAGES|

RAPIDITY

REPRODUCIBLE

• DISADAVANTAGES

CAN BE USED ONLY ON DENSE CULTURES

DOES NOT DISTINGUISH BETWEEN LIVING AND DEAD CELLS

CAN NOT BE USED ON CELLS THAT AGGREGATE

NEED STANDARD CURVE

DRY WEIGHT

• CENTRIFUGATION OR FILTRATION

• DRYING IN OVEN AT 105 DEGREES C FOR 24 HOURS

• ADVANTAGES

USED TO MAKE STANDARD CURVE FOR MEASURING CELL MASS

ACCURATE

REPRODUCIBLE

DISADVANTAGES

TIME CONSUMING

TEDIOUS

SAMPLE MUST CONTAIN MORETHAN 10 MILLION CELLS

METABOLIC ACTIVITY

• RATE OF METABOLITE PRODUCTION

• UTILIZATION OF SUBSTRATE

• REDUCTION OF DYES

ADVANTAGES

CAN BE USED WITH COMPLEX MEDIA SUCH AS MILK OR SOIL

NO INSTRUMENTS REQUIRED

DISADVANTAGES

INDIRECT MEASURMENT

DOES NOT GIVE AN ACCURATE MEASUREMENT

TIME CONSUMING

DIRECT COUNT

• PETROFF HAUSER COUNTING CHAMBER

• COULTER COUNTER

PETROFF HAUSSER COUNTING CHAMBER

COULTER COUNTER

MICROSCOPIC VS ELECTRONIC COUNTS

• USED IN DIFFERENT SITUATIONS

MICROSCOPIC COUNTS

• ADVANTAGES– NO EXPENSIVE

EQUIPMENT

– ONLY WAY TO COUNT IF SAMPLE CONTAINS FOREIGN MATERIALS

• SLOW• TEDIOUS• NOT USEFUL FOR

DILUTE CULTURES

ELECTRONIC COUNT

• ADVANTAGES– RAPID

– ACCURATE IF CELLS ONLY ARE PRESENT

• EXPENSIVE• CAN’T USE IF

FOREIGN PARTICLES ARE PRESENT

PLATE COUNT

• POUR PLATE

• SERIAL DILUTIONS

• COUNT PLATES BETWEEN 3O AND 300 COLONIES

• ADVANTAGES– EXTREMELY

SENSITIVE

– DOES NOT NEED COMPLICATED EQUIPMENT

• DISADVANTAGES– SAMPLING ERRORS

– TIME CONSUMING

– TEDIOUS

– LARGE NUMBERS MUST BE COUNTED TO REDUCE SAMPLING ERROR

MOST PROBABLE NUMBER

• A SINGLE LIVE CELL CAN GIVE RISE TO A TURBID CULTURE

• SERIAL DILUTIONS• USES STATISTICAL

TABLE

• ADVANTAGES– ALLOW COUNTS OF

MICROBES THAT ARE DIFFICULT TO GROW ON SOLID MEDIA

– CAN BE USED TO COUNT CELLS IN MIXED LIQUID CULTURE

• DISADVANTAGE– TIME CONSUMING

– TEDIOUS

FILTRATION

• PREPARATION FOR OTHER METHODS

MICROBIAL DEATH

TERMS

• STERILIZATION

• DISINFECTION

• SANITATION

• DECONTAMINATION

• ANTISEPSIS

• MICROBIOSTATIC

• MICROBIOCIDAL

RATE OF MICROBIAL DEATH

• EXPONENTIAL DEATH

• ASYNCHRONOUS

• CAN BE CALCULATED

DECIMAL REDUCTION TIME

• D VALUE

• TIME IT TAKES TO KILL 90 PERCENT OF POPULATION

FACTORS THAT AFFECT D VALUE

• TEMPERATURE

• TYPE OF MICROBE

• PHASE OF GROWTH

• PRESENCE OF OTHER SUBSTANCES

PROBABILITY OF STERIZATION

• 90 PERCENT OF POPULATION DIES

• EVENTUALLY WE HAVE THE PROBABILITY OF NO MICROBES IN THE POPULATION

DESIGNING A STERILIZATION PROGRAM

• D VALUE OF TREATMENT

• NUMBER OF CELLS PRESENT

• DEGREE OF CERTAINTY OF STERILITY DESIRED

THERMAL DEATH POINT

• TDP

• LOWEST TEMPERATURE NEEDED TO KILL ALL MICROBES IN A LIQUID SUSPENSION IN 10 MINUTES

THERMAL DEATH TIME

• TDT

• MINIMAL TIME TO KILL ALL MICROBES IN A LIQUID SUSPENSION AT A GIVEN TEMPERATURE

PHYSICAL CONTROLS OF MICROBIAL GROWTH

• HEAT

• COLD

• RADIATION

• FILTRATION

• DRYING

• OSMOTIC STRENGTH

HEAT

• INEXPENSIVE

• EFFECTIVE

• DRY HEAT

• MOIST HEAT

AUTOCLAVE

• USES STEAM TO STERILZIE

• MAINTAINS PRESSURE AT 103 kPa (15 PSI)

• KILLS ALL BACTERIA, VIRUSES, FUNGI AND ENDOSPORES– EXCEPT STRAIN 121 AND PRIONS– DOES NOT DESTROY ENDOTOXINS

PASTEURIZATION

• DISINFECTION PROCESS

• MILK, WINES, BEERS……

COLD

• BY ITSELF DOES NOT KILL

• COLD SHOCK ONLY EXCEPTION

• MICROBIOSTATIC

FREEZING

• DOES KILL MOST BACTERIA

• DOES KILL EUKARYOTES

RADIATION

• ELECTROMAGNETIC RADIATION

• ULTRAVIOLET RADIATION

• IONIZING RADIATION

UV RADIATION

• WAVELENGTH OF 10 TO 400 nm

• 265 nm UV LIGHT MOST LETHAL

• GERMICIDAL LIGHTS

• 253.7 nm LIGHT

IONIZING RADIATION

• X-RAYS• GAMMA RAYS• CAUSE CHAIN OF

IONIZATIONS• KILL CELLS

FILTRATION

• MICROBES EXCEPT VIRUSES REMOVED

• NOT STERIZATION

• USED FOR HEAT

• LABILE MEDIA

DRYING

• EVAPORATION

• SUBLIMATION

EVAPORATION

• REMOVAL OF WATER

• USED FOR FOOD

• SELDOM USED IN

• MICRO LAB

LYOPHILIZATION

• SUBLIMATION• DIRECT

CONVERSION FORM SOLID STATE TO GASEOUS STATE

• VACUUM

OSMOTIC STRENGTH

• USED TO PRESERVE FOOD

• SUGAR• SALT

CHEMICAL CONTROL OF MICROBES

TERMS

• CHEMOTHERAPEUTIC AGENTS

• GERMICIDES

• GERMISTATS

• DISINFECTANTS

• ANTISEPTICS

SELECTING A GERMICIDE

• HIGH ACTIVITY GERMICIDE

• INTERMEDIATE ACTIVITY GERMICIDE

• LOW ACTIVITY GERMICIDE

SELECTING A GERMICIDE

• HIGH ACTIVITY GERMICIDE

• INTERMEDIATE ACTIVITY GERMICIDE

• LOW ACTIVITY GERMICIDE

TESTING GERMICIDES

• SERIAL DILUTIONS

• PHENOL COEFFICIENT

• PAPER DISC METHOD

• USE DILUTION TEST

TYPES OF GERMICIDES

• PHENOLS , PHENOLICS & BISPHENOLS

• BIGUANIDES

• ALCOHOLS

• HALOGENS AND PEROXYGENS

• HEAVY METALS

• SURFACTANTS

• ALKYLATING AGENTS

PHENOLS, PHENOLICS & BISPHENOLS

• PHENOL– CARBOLIC ACID

• PHENYLPHENOL• HEXACHLOROPHENE• INACTIVATE VITAL CELLULAR

PROTEINS• PHENOLICS DISRUPT CELL

MEMBRANES

BIGUANIDES

• CHLORHEXIDINE

ALCOHOLS

• DISRUPT LIPIDS IN CELL MEMBRANES

• DISRUPT PROTEINS• ETHANOL• ISOPROPANOL

HALOGENS

• OXIDIZING AGENTS• INACTIVATE ENZYMES• ATTACK SULFHYDRYL

GROUPS• IODINE• CHLORINE

PEROXYGENS

OZONE, HYDROGEN PEROXIDE AND PERACETIC ACID

OZONE

• HIGHLY REACTIVE• SUPPLEMENTS

CHLORINE IN WATER TREATMENT

HYDROGEN PEROXIDE

• OXIDIZING AGENT• WORKS LIKE

HALOGENS• 3% AS ANTISEPTIC

OR DISINFECTANT

PERACETIC ACID

• EFFECTIVE AGAINST SPORES AND VIRUSES

• FOOD AND MEDICAL INSTRUMENT USES

HEAVY METALS

• MERCURY

• SILVER

• MERCURIC CHLORIDE

• MERTHIOLATE AND MERCUROCHROME

• COLLOIDAL SILVER AND SILVER SALTS

SURFACTANTS

• HYROPHILIC AND HYDROPHOBIC PORTIONS

• FORM EMULSIONS

• QUATERNARY AMMONIUM SALTS

• ANIONIC SURFACTANTS

ALKYLATING AGENTS

• FORMALDEHYDE--FORMALIN

• ETHYLENE OXIDE

• GLUTARALDEHYDE

• ATTACH SHORT CARBON CHAINS INTO ENZYMES

• INACTIVATES THEM AND CELL DIES

FORMALDEHYDE

GLUTARALDEHYDE

ETHYLENE OXIDE

Microbial Characteristics and Microbial Control

CHEMOTHERAPEUTIC AGENTS

INTERNET RESOURCES

• http://gsbs.utmb.edu/microbook/ch011.htm

ANTIMICROBIAL CHEMOTHERAPY

THE USE OF CHEMICALS TO CONTROL OR PREVENT

INFECTION

CHEMOTHERAPY

THE USE OF CHEMICALS TO TREAT, RELIEVE OR PREVENT

DISEASE

SOURCES OF ANTIBACTERIAL AGENTS

• http://helios.bto.ed.ac.uk/bto/microbes/penicill.htm

• BACTERIA– STREPTOMYCES– BACILLUS

• FUNGI– PENICILLIUM– CEPHALOSPORIUM

SCOPE OF ANTIMICROBIAL ACTION

• NARROW SPECTRUM

• BROAD SPECTRUM

INTERACTIONS BETWEEN HOST, MICROBE, AND DRUG• DRUG ADMINISTRATION

• DRUG ABSORPTION AND DISTRIBUTION

• DESTRUCTION OR INHIBITION OF MICROBE

• DRUG INACTIVATION BY HOST

DRUG ADMINISTRATION

• PER OS

• INTRAMUSCULAR INJECTION

• INTRAVENOUSLY

• TOPICAL

• INJECTION INTO BODY CAVITY OR SUBCUTANEOUSLY

INTERACTIONS BETWEEN HOST, MICROBE, AND DRUG• DRUG ADMINISTRATION

• DRUG ABSORPTION AND DISTRIBUTION

• DESTRUCTION OR INHIBITION OF MICROBE

• DRUG INACTIVATION BY HOST

DRUG ELIMINATION

• SOME DRUGS METABOLIZED IN LIVER

• MOST ELIMINATED BY KIDNEYS

• PROBENECID SLOWS RATE OF EXCRETION BY KIDNEYS

• SOME DRUGS EXCRETED BY LIVER IN BILE AND IN FECES

MECHANISMS OF DRUG ACTION

INTERACTION BETWEEN DRUG AND MICROBE

SELECTIVE TOXICITY

• INHIBIT OR KILL MICROBES

• HAVE LITTLE IF ANY EFFECT ON HOST TISSUES

MECHANISMS OF DRUG ACTION

• INHIBIT CELL WALL SYNTHESIS

• INHIBIT NUCLEIC ACID SYNTHESIS

• INTERFERE WITH PROTEIN SYNTHESIS

• INTERFERE WITH THE FUNCTION OF THE CELL MEMBRANE

• ANTIMETABOLITE

• INACTIVATE ENZYMES

ANTIMICROBIAL DRUGS THAT AFFECT THE BACTERIAL CELL

WALL

• PEPTIDOGLYCAN TARGET

• CELL WILL LYSE WITHOUT IT

• PENICILLINS

• CEPHALOSPORINS

• VANCOMYCIN

• BACITRACIN

PENICILLIN

CEPHALOSPORIN

VANCOMYCIN

BACITRACIN

ISONIAZID

ETHAMBUTOL

DRUGS THAT DISRUPT THE CELL MEMBRANE

• DIE FROM METABOLIC INSUFFICIENCY

• LYSIS

• POLYMIXINS

• POLYENES

• IMIDAZOLES

• ACTS ON LIPIDS IN MEMBRANES

• NOT AS GOOD SELECTIVE TOXICITY

POLYMIXINS

NYSTATIN

AMPHOTERCIN B

IMIDAZOLES

. .

DRUGS THAT INHIBIT PROTEIN SYNTHESIS

• AFFECT 70s RIBOSOME

• 30s SUBUNIT----ie. AMINOGLYCOSIDES

TETRACYCLINE

• 50s SUBUNIT----ie. CHLORAMPHENICOL

ERYTHROMYCIN

• BACTERICIDAL--AMINOGLYCOSIDES

• BACTERIOSTATIC--ALL OTHER GROUPS

STREPTOMYCIN

ERYTHROMYCIN

TETRACYCLINES

CHLORAMPHENICOL

DRUGS THAT INHIBIT NUCLEIC ACID SYNTHESIS

• LONG METABOLIC PATHWAY

• TOPOISOMERASES--QUINOLONES

• POLYMERASES—RIFAMPIN

• FLUCYTOSINE

RIFAMIPIN

QUNINOLONES

FLUCYTOSINE

DRUGS THAT ARE ANTIMETABOLITES

• ANTIMETABOLITES• INHIBITION OF

FOLIC ACID SYNTHESIS

• SULFONAMIDES• FLUCYTOSINE

ANTIVIRAL DRUGS

• ACYCLOVIR

• AMANTIDINE

DRUGS THAT INACTIVATE ENZYMES

• PENICILLIN & CEPHALOSPORINS

• VANCOMYCIN

EXAMPLES OF SIDEFFECTS

• TOXICITY

• HYPERSENSITIVITIES

• DISRUPTION OF NORMAL FLORA

TOXICITY

SOME DRUGS HAVE TOXIC EFFECTS ON PATIENTS

HYPERSENSITIVITIES

• SOME ALLERGENS

• SOME HAPTENS

• MILD TO SERVERE SKIN RASHES

• ANAPHYLACTIC SHOCK

DISRUPTION OF NORMAL FLORA

• ESPECIALLY BROAD SPECTRUM

• SKIN, DIGESTIVE, UPPER RESPIRATORY, UROGENITAL TRACT

• CANDIDA

• SUPERINFECTION

• LACTINEX IS GIVEN TO COUNTERACT

DRUG RESISTANCE

• ADAPTIVE RESPONSE OF MICROORGANIMS

• RESULT OF DRUG THERAPY, GENETIC VARIABILITY AND NATURAL SELECTION

REASONS FOR SUPERINFECTIONS

• OFTEN PATIENTS ARE DEBILITATED AND HAVE LESS RESISTANCE

• THE CARE ENVIRONMENT OFTEN HAS DRUG RESISTANT ORGANISMS PRESENT

DRUG RESISTANCE• GENETIC MECHANISMS• NONGENETIC MECHANISMS• http://images.google.com/imgres?imgurl=http://

microvet.arizona.edu/Courses/MIC438/decker/AntibioticRes/20-T02_Activity.jpg&imgrefurl=http://microvet.arizona.edu/Courses/MIC438/decker/AntibioticRes/AntibioticResistance.html&h=361&w=800&sz=55&tbnid=GLwmlTgTlJqRoM:&tbnh=64&tbnw=142&hl=en&start=7&prev=/images%3Fq%3Dspectrum%2Bof%2Bantibiotic%2Baction%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG

• http://images.google.com/imgres?imgurl=http://www.wiley.com/college/pratt/0471393878/student/activities/bacterial_drug_resistance/resistance_transfer_web.jpg&imgrefurl=http://www.wiley.com/college/pratt/0471393878/student/activities/bacterial_drug_resistance/&h=285&w=400&sz=27&tbnid=mH0fjM9zuN7zXM:&tbnh=85&tbnw=120&hl=en&start=9&prev=/images%3Fq%3DDRUG%2BRESISTANCE%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG

NONGENETIC MECHANISMS

• EVASION

• L FORMS

GENETIC MECHANISMS

DEVELOPMENT OF DRUG RESISTANCE

• MUTATIONS

• TRANSFORMATION

• TRANSDUCTION

• CONJUGATION

• RESISTANCE FACTORS

• http://www.methylgene.com/images/gestion/BetaLactamase.swf

MUTATIONS

CONJUGATION

TRANSFORMATION

GENERALIZED TRANSDUCTION

SPECIALIZED TRANSDUCTION

SPECIFIC MECHANISMS• SYNTHESIS OF ENZYMES THAT INACTIVATE

DRUG• DECREASE IN CELL MEMBRANE

PERMEABILITY AND UPTAKE• CHANGE IN NUMBER OF AFFINITY OF

RECEPTOR SITES• MODIFICATION OF METABOLIC PATHWAYS• DORMANCY• L FORMS

MECHANISMS OF DRUG INACTIVATION—ENZYMES

• ENZYMES THAT ALTER DRUG STRUCTURE

• BETA-LACTAMASES

• PENICILLINASE

• CEPAHLOSPORINASE

• STAPHYLOCOCCUS AUREUS AND NESSERIA GONORRHOEAE

• SOME GRAM NEGATIVE BACTERIA

MECHANISMS OF DRUG INACTIVATION--ADDITION OF

FUNCTIONAL GROUPS• AMINOGLYCOSIDES

• CHLORAMPHENICOL

• PREVENTION OF ATTACHMENT TO BACTERIAL RIBOSOME

DECREASED PERMEABILITY OF CELL TO DRUG

• GRAM NEGATIVE OUTER MEMBRANE

• PUMP THE DRUG BACK OUT OF CELL

CHANGE DRUG RECEPTORS

• ALTER NATURE OF DRUG’S TARGET

• ALTER PROTEINS --RIFAMPIN AND STREPTOMYCIN

• ALTER 50s RIBOSOME--CLINDAMYCIN, LINCOMYCIN, ERYTHROMYCIN

• CHANGE BINDING SITE IN CELL WALL-PENICILLIN & METHAICILLIN

• DECREASE SYNTHESIS OF ERGOSTEROL IN FUNGAL CELL WALL--AMPHOTERCIN B

CHANGE METABOLIC PATHWAYS

• DEVELOP ALTERNATE PATHWAY OR ENZYME

• SULFONAMIDE AND TRIMETHROPIM RESISTANCE

• SHUT DOWM PATHWAY

• FLUCYTOSINE

THE ROLE OF NATURAL SELECTION IN DRUG RESISTANCE

• OCCURS IN WHOLE POPULATION

• VARIATION IN POPULATION

• RESISTANT STRAINS MAY BE IN LOW NUMBERS

• IN PRESENCE OF ANTIBACTERIAL AGENT NON RESISTANT DIE

• RESISTANT FORMS INCREASE DUE TO REPRODUCTION

• http://www.geocities.com/Heartland/7547/antibios.html

FIRST, SECOND AND THIRD LINE DRUGS

FIRST, SECOND AND THIRD GENERATION DRUGS

• DRUGS THAT ARE DERIVATIVES OF ONE ANOTHER

• MAY BE USED AS LINE DRUGS

CROSS RESISTANCE

• RESISTANCE TO TWO OR MORE DRUGS

• BETA-LACTAMASE

NOSCOMIAL DRUG RESISTANT INFECTIONS

• SULFONAMIDES FIRST ANTIBACTERIAL AGENT

• FIRST TO HAVE RESISTANT SPECIES DEVELOP

• PENICILLIN NEXT ADVANCE

• AT FIRST 95+% OF ALL STAPH. AUREUS WERE SUSCEPTIBLE

• NOW 95+% OF ALL STAPH. AUREUS ARE RESISTANT

EXAMPLES OF RESISTANT SPECIES

• STAPHYLOCOCCI

• GONOCOCCI

• SALMONELLA

• NEISSERIA

• PSEUDOMONAS

NOSOCOMIAL INFECTIONS

• SICK PEOPLE FREQUENT HOSPITALS

• TEND TO BE MORE SEVERELY ILL

• HAVE LOWERED RESISTANCE TO DISEASE

• HOSPITALS USE LOTS OF ANTIBACTERIAL AGENTS

HOW TO REDUCE ANTIBACTERIAL AGENTS THAT ARE RESISTANT NOSOCOMIAL

INFECTIONS• WASH YOUR HANDS

• LIMIT THE USE OF ANTIBACTERIAL AGENTS

• USE SENSITIVITY TESTS

• USE ANTIBACTERIAL AGENTS UNTIL ORGANISM IS COMPLETELY ERADICATED

• USE DRUG COMBINATIONS

DETERMINING MICROBIAL SENSITIVIES TO ANTIMICROBIAL

AGENTS• DISK DIFFUSION METHOD

• DILUTION METHOD

• SERUM KILLING POWER

• AUTOMATED METHODS

• http://www.lancet.co.za/assets/pdf/news/Antimicrobial_Susceptibility_Tests.pdf

DISK DIFFUSION METHOD

• KIRBY BAUER METHOD

• ZONES OF INHIBITION

• 24-48 HOURS• SENSITIVE• MODERATELY

SENSITIVE• RESISTANT

DILUTION METHOD• STANDARDIZED

SHALLOW WELLS• SPECIMEN INTRODUCED

INTO BROTH AND DRUG• 16-20 HOURS• MINIMUM INHIBITORY

CONCENTRATION• MINIMUM

BACTERIOCIDAL CONCENTRATION

SERUM KILLING POWER

• PATIENT’S SERUM• BACTERIAL

SUSPENSION• LOOK FOR

TURBIDITY

INCREASING DRUG EFFECTIVENESS

THE IDEAL CEHMOTHERAPEUTIC AGENT

• SOLUBLE IN BODY FLUIDS

• SELECTIVE TOXICITY

• NOT EASILY ALTERED TO TOXICITY

• NONALLERGENIC

• STABILITY--ABILITY TO MAINTAIN CONSTANT THERAPEUTIC CONCENTRATION

THE IDEAL CHEMOTHERAPEUTIC AGENT

• FEW ORGANISMS ARE RESISTANT

• LONG SHELF LIFE

• REASONABLE COST