Micro general info

8/14/2019 Micro general info

1/36

Dr. Rose Elaine D.Tan

INTRODUCTION TO MICROBIOLOGY


2/36

What is Microbiology?

Micro - too small to be seen with the naked eye

Bio life

ology - study

Definition Microbiologybranch of biology which deals with the study of

minute living microorganism usually not visible tothe naked eye


3/36

Scope of Microbiology

Bacteriology study of Bacteria

Phycology study of Algae

Parasitology study of Parasites

Mycology study of Fungi

Virology study of Virus

Immunology study of cells, molecules andmechanisms responsible forimmunity


4/36

Bacteria - what comes to mind?

DiseasesInfections

Epidemics

Food Spoilage

Only 1% of all known bacteria cause humandiseases

About 4% of all known bacteria cause plantdiseases

95% of known bacteria are non-pathogens

Normal microbiota: microorganisms that arenormally found on or in the body and do

not cause disease


5/36

BENEFITS OF MICROORGANISMS

Decompose organic wastes Are producers in the ecosystem by photosynthesis

(algae, cyanobacteria, etc)

Produce industrial chemicals such as ethanol andacetone

Produce fermented foods (vinegar, cheese, bread, beer,wine)

Fermentation also produces useful products such as solventsto dissolve substances

To be probiotic means to add microbes to your diet

Produce products used in manufacturing (e.g.cellulose) and treatment of diseases (e.g. E colican make insulin)

Microbes are used to produce Antibiotics- Penicillin

Microbial Antagonism- our normal microbial flora prevents potential


6/36

Insect Pest Control- Using bacteria to control the growth of insects (Bacillus

thuringiensis)caterpillarsbollwormscorn borers

Recombinant DNA Technology, Gene Therapy, GeneticEngineering

a new technique for biotechnology Bacteria & fungi can be manipulated to produce enzymes

and proteins they normally would not produce Insulin Human Growth Hormone Interferon Vaccines

Bioremediation bacteria degrade organic matter in sewage Bacteria also degrade or detoxify pollutants such as oil and

mercury

Using microbes to clean up pollutants and toxic wastes Exxon Valdez - 1989


7/36


8/36

BRIEF HISTORY

before microorganism were discovered, ancientpeople regarded diseases as a form ofpunishment sent by GOD for the sins of men

disease were not new to man

Biblical disease - Leprosy- Tuberculosis

- Syphilis

- Plague

treatment and prevention of these diseases weresought by sacrifices and lustration to appease theanger of God


9/36

Varro = during the 2nd century B.C. postulated the

concept of contagiondiseases are transmittedby invisible creature

Roger Bacon (13th century) = postulated thatinvisible

living things called germs produced

disease

Fracastorius (1546) = postulated that disease iscaused by invisible living things and can

be


10/36

Anton Van Leewenhoek 1st described bacteria in 1677 with the use of a

simple microscope utilizing crude lenses

1st person to actually see livingmicroorganisms

described the 3 major forms of bacteria (rod,sphere, spiral) fungi, protozoa, spermatozoa

considered as the Father of Bacteriology

It was not until 150 years later that thisinvisible living creatures begin to beassociated with human

diseases Germ theory of diseases


11/36


12/36

Robert Hooke 1665= developed the compound microscope

that used reflected light and was able

to confirm Leeuwenhoeksdiscoveries

= Founded the field ofMicroscopic Biology throughhis published work -"Micrographia

= first person to coin the word

cell to describethe tiniest components ofliving systems


13/36

Spontaneous Generation Theory

many scientist at that time believed that lifecould develop spontaneously from

decomposing non-living material

Supported by appearance of living creatures indecaying meat, stagnating ponds, fermentinggrain, and infected wounds


14/36

Spontaneous GenerationTheory

Francesco Redi 1668This theory was not refuted until the 17th century

when he demonstrated the appearance of maggotsin decomposing meat as a result on the depositionof eggs by flies

Rudolph Virchow 18581st person to propose the Theory of Biogenesis Cells can only arise from preexisting cells

John Tyndallproved that dust carried germsalso found out that bacterial spores could be killed

by successive heatingtyndallization (Fractional sterilization) - heating

with free-flowing steam for 30-60min for 3

consecutive days at 100C


15/36

By 1860, the debate had become so heatedthat the Paris Academy of Sciences offered aprize for any experiments that would helpresolve this conflict

The prize was claimed in 1864 by LouisPasteur, as he published the results of an

experiment he did to disproved spontaneousgeneration in microscopic organisms

Giving rise to the

Theory of Biogenesis


16/36

The Theory of Biogenesis Experiment showed that life did not spontaneously

appeared Meat broth was boiled in a flask to kill microorganismsThe neck of the flask was heated and bent into the shape of

an S Microorganisms could not get into broth because they

would settle in S shaped neck before contact with broth

No growth was in discovered in the broth Broth was tilted into the S component and

microorganisms contaminated broth and grew


17/36

Pasteurization

Introduced by Louis Pasteur

For fresh beverages such as milk, fruit juices, beerand wine w/c are easily contaminated duringcollection and processing

Require special vats and heat exchangers toexpose the liquid to 71.6C 15sec (flashmethod) or to 63-66C for 30min (batchmethod)


18/36

Germ Theory of Diseasedeveloped by Louis Pasteurit states that each specific infectious disease is

caused by a specific microorganism

1860s:Joseph Lister used a chemical disinfectant(aqueous phenol) to prevent surgical woundinfections after looking at Pasteurs work showing

microbes are in the air, can spoil food, and causeanimal diseases- also developed the first pure culture techniqueusing liquid medium which was the key toidentification of bacteria

1876: Robert Koch establish proof of the microbialetiology of 3 important diseases of this day:

Cholera (Vibrio cholerae) Tuberculosis (Mycobacterium tuberculosis)

Anthrax (Bacillus anthracis)provided the Kochs postulates which are experimental


19/36

Kochs Postulate criteria(1) The organism must always

be found in diseased animals

and not in healthy one

(2) Organisms isolated from

the diseased animals must

be grown in pure culture

away from the diseased animals

(3) Organisms grown in pure

culture must initiate and reproduce

the disease when re-inoculated into

susceptible animal

(4) Organisms must be

re-isolated from experimentally

infected animals


20/36

Exceptions to the Kocks Postulate :

1) Carrier person = some individual harbors theorganism but do not manifest the diseaseand can transmit the disease to others

2) Some or certain organisms/bacteria cannot be

cultured in vitro (cannot grow in artificial CM)Ex. Mycobacterium leprae / Treponema pallidum

3) Certain animal not susceptible to certainmicroorganism some animals are by natureimmune

cannot replicate even with the same speciesome bacterial specie are host specific

Ex. Vibrio cholerae cannot cause chicken

cholera or vice versa


21/36

The Golden Age of Microbiology1857-1914

Beginning with Pasteurs work, discoveries included the

relationship between microbes and disease, immunity, andantimicrobial drugs

PasteurPasteurizationFermentation

Joseph ListerPhenol to treat surgical wounds 1st attempt to control

infections caused bymicrooganisms

Robert KochKochs Postulates

Edward Jennervaccination

Paul Erlich1st synthetic drug used to treat infectionsSalvarsan - arsenic based chemical to treat Syphilis salvation from Syphilis


22/36

The Birth of Modern Chemotherapy

1928: Alexander Fleming discovered the firstantibiotic

He observed that Penicillium fungus made anantibiotic, penicillin, that killed S. aureus

1940s: Penicillin was tested clinically and massproduced


23/36

Mi bi l


24/36

MicrobialTaxonomyarea of biologic science comprising of 3 distinct but

highly interrelated disciplines that includeclassification, nomenclature and identification

Taxonomy: the science of the classification oforganisms

Carl Linnaeus, also known asCarl von Linn or Carolus

Linnaeus,is called the Father of Taxonomy

His system for naming, ranking, &

classifying organisms is still in wideuse He established the system ofscientific nomenclature: Genus &specie


25/36

Classification

organization of microorganisms that share similarmorphologic, physiologic and genetic traits intospecific groups or TAXA

Species: most basic taxonomic group and maybe defined as a collection of bacterial strains thatshare many common physiologic and geneticfeatures and as a group differ notably from

other bacterial specie

Genus: comprised of different species that haveseveral important features in common but differ

sufficiently to still maintain their status asindividual s ecie


26/36

Levels of ClassificationTaxon:

A group or level of classification

Hierarchical; broad divisions are divided up intosmaller divisions:

KingdomPhylum

Class

OrderFamily

Genus

Species


27/36

Identificationprocess by which a microorganisms key features are

delineated

the profile is compared with those of other previouslycharacterized microorganisms so that the organism inquestion can be classified within the most appropriate taxaand can be assigned an appropriate Genus and Species name

General categories of identification method:

Genotypic characteristicsRelate to an organisms genetic make-up including the

nature of the organisms genes and constituent nucleic acid

Phenotypic characteristicsBased on features beyond the genetic level and includes

readily observable characteristics and those characteristicsthat require extensive analytic procedures to be detected

Morphology, staining rxn., antigenic properties,environmental & nutritional requirements, resistance profiles


28/36

Nomenclature

naming of microorganisms according toestablished rules and guidelines provide theaccepted labels by which organisms areuniversally recognized

Scientific name (Systematic Name)

Binomial System of NomenclatureThe first letter of the genus name is always capitalized,

but never the first letter of the species name

Genus and species are either underlined or italicized

A genus name may be used alone to indicate a genusgroup; a species name is never used alone

The genus may be abbreviated with the first letter,and the species is written out

Eschericia coli

E. coli

acceptable


29/36

before microorganisms were discovered all livingthings were believed to be either plants and

animals no transition type were thought to exist

after discovery of microorganism

it was clear that microorganism combines bothplant and animal properties


30/36

Haeckel proposed that microorganism be placed inanother kingdom

Kingdom Protista members of this kingdom are distinguished from plants and

animals

Algae

Protozoa

Fungi Molds (multicellular) Yeasts (single-celled)

Kingdom Monera Monera is the only "kingdom" containing prokaryotic

organisms

Bacteria-


31/36

Kingdom Protista

members of this kingdom are distinguished fromplants and animals by their followingcharacteristics

1. Simple organization2. Unicellular or Multicellular

Protist- undifferentiated unicellular organisms that do not form thespecialized tissues and organ systems of higher plants and

animals

2 Distinct Cell types:1) Eucaryote (Higher Protista)

2) Procaryote (Lower Protista)


32/36

EUCARYOTEShigher protists ex: algae (red algae, brown algae, greenalgae) fungi

protozoaslime molds


33/36

characteristics:- possess a well defined nucleus w/c contain the genetic

information of the cell in multiple strands of DNA and proteinscalled chromosomes

- nucleolus w/c exist w/in the nucleus and plays a role inthe production of ribosomal RNA and ribosomes

- contain membrane enclosedorganellesthat have specificcellular functions and site where chemical activities takes

place

- cytoskeleton which provides support for the differentorganelles

- contain complex phospholipids, sphingolipids, histones, sterols- mitochondria are sites of energy production for cellular work- ribosomes are masses of RNA and proteins that function as the

sitefor protein synthesis

- golgi apparatus is where protein is packed for export- endoplasmic reticulum is involved in the transport of newly

synthesized proteins

-lysosomesare vesicles that contain enzymes for cellulardigestive process


34/36

PROKARYOTES

lower protists bacteria,

cyanobacteria (blue-green algae)archaebacteria (methanogens,extreme halophiles,thermoacidophiles)

characteristics:- lack a nucleus or nuclear membrane- has a ribosome- have no organelles, histones and

only in rare cases complex phospholipids,

sphingolipids and sterols- chemical activities takes place in the cytoplasm- have a cell wall composed of peptidoglycan with muramic acid- are haploid with a single chromosome composed solely of DNA

method of cell division: binary fission


35/36

Eucaryote Procaryote

nucleus true nucleus enclosed

in a well-defined

nuclear memb.

Primitive /

Rudimentary not

enclosed in nuclear

memb.

chromosomes multiple Only 1

mitochondria present absent

ribosomes 80s 70s

Mitotic apparatus present absent

Motility organelle multistranded unstranded

size 20um 0.3 2um

examples Red & Brown algae,

Protozoa, slime molds,

fungi

Bacteria,

Blue green algae


36/36

Micro general info

Documents

Transcript of Micro general info