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