Aaamicrobiology 1st Disscussion

Microbiology

Introduction to Microbiology

Microbiology: The science  The study of minute organism or microbes  It concern with its form, structure, reproduction,

physiology, metabolism and identification  It also includes the study of their distribution in nature, their relationship to one another as well to other organism, their benefits , and detrimental effects on man, and chemical changes they make in their environment

Defferent types of micro organism  Bacteria  Fungi  Virus  Protozoa  Algae  parasites

Applied areas of microbiology  Bacteriology  Mycology  Phycology  Protozoology  Virology

Occupation of professional microbiologist  Medical microbiologist  Public health microbiologist  Immunologist  Agricultural microbiologist  Microbial ecologist  Industrial microbiologist

Biological importance  Photosynthesis  Decomposers  Nitrogen fixation  Digestion  Drugs

- antibiotic- penicillin, polymyxin, bacitracin - vaccine- anti-polio, hepa, BCG,

Microbes Found in Food  Grains

 Produce

 Meats/Poultry

Microbes Found in Food (cont.)  Fish/Shellfish

 Milk

 Other

Preventing Disease and Food Spoilage  Canning

 Refrigeration/ Freezing

 Drying

Preventing Disease and Food Spoilage  Irradiation

 Chemical Preservatives

 Pasteurization

Microbes as Food  Fungi

 Algae

 Bacteria

Microbes in Food Production  Bread

 Dairy/Cheese

 Other Fermented foods

Alcoholic Beverages — Beer  Beer/Ales

Alcoholic Beverages — Beer

Alcoholic Beverages — Wine  Wine

 Spirits

Industrial and Pharmaceutical Microbiology  Metabolic Processes

 Challenges

 Reactor Types

Useful Organic Products  Simple

Organics

 Antibiotics

 Enzymes

Useful Organic Products (cont.)  Amino Acids

 Other

Biologicals

Microbial Mining/Waste Disposal  Mining

 Wastes

Detrimental effects on humans

 Biochemical weapons

Microbial diseases  plague or black death  Tuberculosis ( mycobacterium )  Anthrax (cutaneous, gastrointestinal, pulmonary )  Pox virus ( small pox ) variola major, varicella virus     

( chicken pox ) hepatitis virus Dengue AIDS ( other STD e.g. syphyllis, herpes ) Chicken flu Gastointestinal infection( salmonella, shigella, e.coli )

Pioneers in the Science of Microbiology

Robert Koch  1876- identification of

bacillus anthracis  1878- differentiation of staphylococci  1882- identification mycobacterium tuberculosis  1883- identification of vibrio cholerae

 He develop the methods of fixing, staining

and photographing bacteria  He develop the method of cultivating bacteria on solid media.

Koch’s postulates  a particular microorganism must be found in all cases of

disease and must not be present in healthy animals or humans  the microorganism must be isolated from the diseased animal or human and grown in pure culture in the laboratory.  the same disease must be produced when microorganism from the pure culture are inoculated into healthy susceptible laboratory animal  the same microorganism must be recovered from the experimentaly infected animal and grown again in pure culture

Exceptions to Koch’s postulates  Koch’s postulate the growth of pathogen using culture

media but some pathogen will not grow on artificial culture media e.g. virus, rickettsiae, treponema pallidum  Koch’s postulate it is necessary to infect laboratory animals with the pathogen being studied but many pathogen infect only one specie of animal  Certain diseases called synergistic infection are caused by more than one microorganism or pathogen  Some pathogen when cultured artificially becomes less pathogenic and no longer infect animal after being cultured.

Anton van Leeuwenhoek (1632-1723)  First person to see

bacteria and protozoans  Referred as father of microbiology or bacteriology

Louis Pasteur (1822-1895)  Different organism produce

different fermentation products e.g. glucose in grapes produces ethyl alcohol. Acinetobacter convert glucose to acetic acid producing vinegar.  Postulated the theory of spontaneous generationidea that life arise from non living material

 Championed changes in hospital practices to

minimize the spread of disease by pathogens  Develop vaccine to prevent chicken pox, cholera, anthrax and swine erysipelas  Develop vaccine that prevent rabies in dog and in humans  Introduced the terms aerobes and anaerobes  Develop the process of pasteurization. 55C for several minutes, today we use 73-75 C for 15 seconds or 63-65 C for 30 min.

 Gerard Armauer

Hansen- discovery of mycobactrium leprae

 Albert Neisser- discovery

of neisseria gonorrhrea

 Arnold karl Klebs-

discovery of corynebactrium diptheriae

 David Bruce- identification

of brucella melitensis

 Shiga kiyoshi- shigella

dysenteriae

 Emile Roux and

shibasabuso kitasatodiscovery of yersinia pestis

 1867- Joseph Lister-

publishes his work on antiseptic surgery

 Karl joseph Eberth –

discovery of salmonella typhi

 Jules Bordet and

gengou- bordetella pertussis

 1921- alexander

Flemming discovers penicillin

Other contribution in microbiology  Shaudinn and Hoffman- discovery of

treponema pallidum  Ashburn and Craig- identification of dengue fever virus  Flexner ad Lewis- identification of poliomyelitis virus  Petri- petri dish  Pfeiffer- haemophilus influenzae

 1546- Giloramo Fracastoro suggests that

invisible organism cause disease  1590- Jansen developed the 1st compound microscope  1786- Muller produce the 1st classification of bacteria  1798- Jenner introduced cowpox vaccine for small pox  1838- schwann and scleiden documented the cell theory

 1869- Mischer discovered nucleic acid  1933- Ruska developed electron microscope  1937- Charlton divides organism to

eukaryotes and prokaryotes  1983-1984- isolation and identification of HIV by Gallo and Montagnier

Microbial classification

Prokaryota or lower protist or monera  with primitive type of nucleus  lacks nuclear membrane  rudimentary nucleus with single chromosome  no mitotic apparatus  schizophyceae- blue green algae  schizomycetes- bacteria, PPLO  microtatobiota- rickettsiae, chlamydiae, virus

Eukaryotes  with well defined nuclear membrane,

chromosomes  exhibit mitotic cell division  kingdom fungi  kingdom plantae  kingdom animalia

Diversity of Microorganism

Algae  Photosynthetic  With pellicle ( thickened cell membrane)  With stigma ( light sensing organelle )  Not plants but more plant like than protozoa

Bacillariophyta ( diatoms )  unicellular algae  silicon dioxide in their cell wall  used to make diatomaceous earth used in

abrasives and insulations

Dinoflagellates  microscopic, flagelated, photosynthetic  referred as fire algae  responsible for red tide

Green algae  spirogyra- filamentous algae and producing

long green strands  chlamydomonas- unicellular, biflagellated with chloroplast and stigma  volvox- multicelluar algae, biflagellated cells  euglena- contains chloroplast, photosynthetic - with stigma and single flagellum

spirogyra

chlamydomonas

volvox

euglena

Rhodophyta ( red algae )

Phaeophyta ( brown algae )

Protozoa  Most are single celled and free living in soil, and    

water They posses pellicles, cytostomes, contractile vacoules, pseudopodia, cilia or flagella Without chlorophyll Some are flagellates others are ciliates With 2 stage: - trophozoite- feeding state, motile, dividing - cyst- dormant survival stage

Phylum of Protozoans

Ciliophora- ciliates  Balantidium coli- dysentery  Paramecium  Stentor  Tetrahymena  vorticella

Balantidium coli

Paramecium

Stentor

Tetrahymena

vorticella

Mastigophora- flagellates  Trypanosoma brucei- african sleeping

sickness caused by tsetse fly  Trypanosoma cruzi- american trypanosomiasis ( chaga’s dse )  Giardia lamblia- diarrheal disease  Chlamydomonas  trichomonas

Sarcodina( pseudopodia )  Amoeba  Naegleria fowleri- amoebic

meningoencephalitis  Entamoeba histolytica- amoebic dysentery

Sporozoea  Plasmodium  Crytosporidium parvum- diarrheal disease  Toxoplasma gondii

Microbial Taxonomy and Nomenclature

 Taxonomy:  Classification of living organisms into groups  Phylogenetic Classification System: 

Groups reflect genetic similarity and evolutionary relatedness

 Phenetic Classification System:  Groups do not necessarily reflect genetic similarity or evolutionary relatedness. Instead, groups are based on convenient, observable characteristics.

Levels of Classification  Taxon:  A group or “level” of classification  Hierarchical; broad divisions are divided up into smaller divisions:       

Kingdom (Not used by most bacteriologists) Phylum (Called “Division” by botanists) Class Order Family Genus (plural: Genera) Species (Both singular & plural)

Nomenclature  Scientific name (Systematic Name)

Binomial System of Nomenclature 

Genus name + species name    



Italicized or underlined Genus name is capitalized and may be abbreviated Species name is never abbreviated A genus name may be used alone to indicate a genus group; a species name is never used alone eg: Bacillus subtilis B. subtilis

Nomenclature  Common or descriptive names

(trivial names) 

Names for organisms that may be in common usage, but are not taxonomic names 





eg: tubercle bacillus (Mycobacterium tuberculosis) meningococcus (Neiserria meningitidis) Group A streptococcus (Streptococcus pyogenes)

Useful Properties in Classification  Colony morphology  Cell shape & arrangement  Cell wall structure (Gram staining)  Special cellular structures  Biochemical characteristics