Medical Microbiology An Introductionjpkc.hrbmu.edu.cn/weisw/Medical Microbiology... · Department...

Medical Microbiology

An Introduction

Medical Microbiology:

An Introduction

Department of Microbiology

Harbin Medical University

Department of Microbiology, Harbin Medical University

Syllabus

Obligatory

classification of microbes.

Comprehensive

relationship between microbes and

human

development history of microbiology.


Outline

An overview of Medical Microbiology

Classification of microorganisms

Brief history

Challenges we meet now

How to study?

Assessment


Five Characteristics of Life

1. Cells

2. Maintain structure by taking up chemicals

and energy from the environment

3. Respond to stimuli in the external

environment

4. Reproduce and pass on their organization

to their offspring

5. Evolve and adapt to the environment


Prokaryotic vs. Eukaryotic

Prokaryotic Cells Without Nuclei And

Membrane-Bound Organelles

Eukaryotic Cells With Nuclei And

Membrane-Bound Organelles


5 Kingdoms of Living Organisms

www.oum.ox.ac.uk


5 Kingdoms of Living Organisms

1. Animalia [1,000,000 species]

2. Plantae [250,000 species]

3. Fungi [100,000 species]

4. Protista [250,000 species]

5. Monera [10,000 species] - Bacteria and

Cyanobacteria

Eukaryotic vs. Prokaryotic


Classification System

Three Domains 1978 Carl Woese 1. Bacteria

Unicellular prokaryotes with cell wall containing peptidoglycan

2. Archaea Unicellular prokaryotes with no peptidoglycan in cell

wall

3. Eukarya Protista

Fungi

Plantae

Animalia


Taxonomic Classification

Kingdom

Phylum

Class

Order

Family

Genus

Species

Animalia

Chordata

Mammalia

Primate

Hominidae

Homo

Sapien

Human Being


Binomial System of Taxonomic

Classification

Use only the Genus and species Homo sapien Felis domestica Escherichia coli Staphylococcus aureus

Genus and species are either underlined or italicized Genus is always Capitilized species is never capitilized


What is Microbiology?

Micro - too small to be seen with the naked eye

Bio - life

ology - study of

Microbiology – Science about small living things

The morphology and structures

Physiology

Pathogenesis and Immunology (medical microbiology)

Treatment and prevention (medical microbiology)


Biological Principles illustrated by

Microbiology

Microbiology

Biochemistry Molecular

Biology Genetics


Evolution

Microorganisms are the products of

evolution

the biologic consequence of natural selection

operating upon a vast array of genetically

diverse organisms

Mutualism Symbiosis

Parasitism

Ecology

An association between

organisms of two different

species in which each member

benefits

A relationship of mutual

benefit or dependence

The characteristic

behavior or mode of

existence of a parasite or

parasitic population The science of the

relationships between

organisms and their

environments


Organisms included in the study

of Microbiology

1. Bacteria

2. Protozoans

3. Algae

4. Parasites

5. Fungi

Yeasts and Molds

6. Viruses

Bacteriology

Protozoology

Phycology

Parasitology

Mycology

Virology

Microorganisms - Microbes - Germs


Organisms Related To Medical

Microbiology

Acellular microbes

Viruses

Prokaryotic microbes

Bacteria

Eubacteria Chlamydia

Spirochetes Rickettsiae

Mycoplasma Actinomycetes

Eukaryotic microbes

Fungi


Microorganisms

Non-cellular organism

Prokaryotes

Eukaryotes

Others Prions Viroid

Fungi

Bacterium

Virus


Viruses

Viruses lack many of the attributes of cells, including

the ability to replicate. Only when it infects a cell does

a virus acquire the key attribute of a living system:

reproduction

A viral particle consists of a nucleic acid molecule,

either DNA or RNA, enclosed in a protein coat, or

capsid

Viruses are known to infect all cells, including

microbial cells. Host-virus interactions tend to be

highly specific

True nucleus

PROKARYOTES

BACTERIA ARCHAEA

EUKARYOTES Prokaryotes

Cyanobacteria Eubacteria

Intron


Pathogenic Prokaryotes

Mycoplasma

Bacteria

Spirochetes

Rickettsia

Chlamydiae

Actinomyces


Eukaryotes

Algae

Fungi

Protozoa

all organisms that produce O2 as a

product of photosynthesis. One major

subgroup of these organisms—the

bluegreen bacteria, or cyanobacteria—

are prokaryotic and no longer are

termed algae

Protozoa are unicellular nonphoto-

synthetic protists. Belongs to

Parasitology

Mold Yeast


Prion

A kind of infectious protein that can resist the

digestion of proteinase

The cellular form of the prion protein (PrPc) is

encoded by the host’s chromosomal DNA

An abnormal isoform of this protein (PrPres) is the

only known component of the prion and is associated

with transmissibility.

Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-

Sträussler-Scheinker disease, fatal familial insomnia

, and Bovine spongiform encephalopathy (BSE)


Viroid

Small, single-stranded, covalently closed circular RNA

molecules existing as highly base-paired

rod-like structures; they do not possess capsids

They range in size from 246 to 375 nucleotides in length. The

extracellular form of the viroid is naked RNA—there is no

capsid of any kind


Viroid

The RNA molecule contains no protein-encoding genes, and the

viroid is therefore totally dependent on host functions for its

replication

The RNAs of viroids have been shown to contain

inverted repeated base sequences at their 3' and 5' ends, a

characteristic of transposable elements and retroviruses. Thus, it

is likely that they have evolved from transposable elements or

retroviruses by the deletion of internal sequences


Bacteria - what comes to mind?

Diseases

Infections

Epidemics

Food Spoilage

Only 1% of all known bacteria cause human

diseases

About 4% of all known bacteria cause plant

diseases

95% of known bacteria are non-pathogens


Microbes Benefit Humans

1.Bacteria are primary decomposers - recycle

nutrients back into the environment

(sewage treatment plants)

2. Microbes produce various food products

cheese, pickles, sauerkraut, green olives

yogurt, soy sauce, vinegar, bread

Beer, Wine, Alcohol


Microbes are used to produce

Antibiotics

Penicillin

Mold

Penicillium notatum

1928 Alexander Fleming

www.studyblue.com


Bacteria synthesize chemicals that our body

needs, but cannot synthesize

Example: E. coli

B vitamins - for metabolism

Vitamin K - blood clotting

Escherichia coli

Dr. Escherich

Colon (intestine)


Microbial Antagonism

Our normal microbial flora prevents

potential pathogens from gaining access to

our body


Recombinant DNA Technology Gene Therapy

Genetic Engineering

Bacteria can be manipulated to produce enzymes and proteins they normally would not produce

Insulin

Human Growth Hormone

Interferon


Microbes are also capable of

causing many diseases

Pneumonia Whooping Cough

Botulism Typhoid Fever Measles

Cholera Scarlet Fever Mumps

Syphilis Gonorrhea Herpes 1

Chlamydia Tuberculosis Herpes 2

Meningitis Tetanus RMSV

Strep Throat Lyme Disease AIDS

Black Plague Diarrhea Gangrene


Brief History of Microbiology


History of the Study of

Microorganisms

1665 Robert Hooke

“little boxes” - “cells”

Cell Theory - all living things are

made up of cells


Anton van Leeuwenhoek 1674

- 1st person to actually see living microorganisms

“wee animalcules”

荷兰人吕文虎克

（Leeuwenhoek）1632-1723


Spontaneous Generation

Theory that life just “spontaneously”

developed from non-living matter

Example:

toads, snakes and mice - moist soil

flies and maggots - manure and decaying flesh


Germ Theory of Disease

Hard for people to believe that diseases

were caused by tiny invisible “wee

animalcules”

Diseases, they thought, were caused by:

demons

witchcraft

bad luck

the wrath of God

curses

evil spirits


Experiments to disprove

Spontaneous Generation

Francesco Redi 1668

Rudolph Virchow 1858

Theory of Biogenesis

Cells can only arise from preexisting cells

Louis Pasteur 1861


Pasteur designed special “swan-necked

flasks” with a boiled meat infusion

Shape of flask allowed air in (vital force) but trapped

dust particles which may contain microbes


Robert Koch 1st to prove that bacteria actually caused diseases

1876

Microbial Etiology of Infectious Disease etiology - the cause of a disease

Established “scientific rules” to show a cause and effect relationship between a microbe and a disease Koch’s Postulates


Koch’s Postulates

1. The same organisms must be found in all cases of

a given disease.

2. The organism must be isolated and grown in pure

culture.

3. The isolated organism must reproduce the same

disease when inoculated into a healthy

susceptible animal.

4. The original organism must again be isolated from

the experimentally infected animal.


Exceptions to Koch’s Postulates

1. Some organisms have never been

grown in pure culture on artificial media Treponema pallidum - Syphilis


Mycobacterium leprae Leprosy

Never been grown in pure culture on artificial media

Abdominal cavity of the Seven Banded Armadillo




In exclusively human diseases, it is not

morally acceptable to inoculate a deadly

pathogen into a “human guinea pig”

HIV


Koch Postulates related 3

important diseases of his day

1. Cholera (fecal-oral disease)

Vibrio cholerae

2. Tuberculosis (pulmonary infection)

Mycobacterium tuberculosis

3. (sheep and cattle)

Bacillus anthracis


Discovery of Virus

Iwanovski

a Russian chemist, 1892

Tobacco Mosaic Disease

Beijerinck confirmed 1898

Walter Reed, USA 1901

Yellow fever virus

1st human virus

Tobacco mosaic disease, caused by the tobacco mosaic virus


Joseph Lister

Phenol to treat surgical wounds

-1st attempt to control infections

caused by microoganisms


Paul Erlich

1st synthetic drug used to treat infections

Salvarsan - arsenic based chemical to

treat Syphilis

“salvation” from Syphilis


Dicovery of Antibiotics

Alexander Fleming (1881-1955)

Sir Alexander Fleming Ernst Boris Chain Sir Howard Walter Florey


Vaccine and Vaccination

16 century Human pox fluid inoculation for

smallpox prevention in China

Edward Jenner, 1749-1823

Cow pox fluid inoculation for

prevention of smallpox

Smallpox was officially

declared eliminated in 1980

worldwide

Golden Age of Microbiology

1857 - 1914


Nowadays

New pathogens emerged continuously

Hepatitis viruses

HIV

Helicobacter pylori

TTV

Prions

The mutations of traditional pathogens

Drug resistance became more severe

Mycobacterium tuberculosis


Importance

Most frequent diseases are infections

Mycobacterium: tuberculosis

Infectious hepatitis

HIV/AIDS

Coronavirus and SARS

Bird flu


Progress of Hepatitis Viruses

1947, concepts of hepatitis A and serum-transmitted hepatitis

1970, Dane particle was observed (hepatitis B virus)

1973, hepatitis A virus

1978, non-A, non-B hepatitis viruses (NANBV)

1989, hepatitis C virus (HCV), hepatitis E virus (HEV)

1990-1994, non A-E hepatitis viruses

1995, hepatitis G virus (HGV)

1997, TT virus (TTV)


Human Immunodeficiency Virus & AIDS

1981, the first case

report about AIDS

1983, HIV was isolated

1990s, HAART (cocktail

therapy) was employed

So far, no effective

vaccine available

www.health.howstuffworks.com

www.virology-online.com


HIV Genome

www.stanford.edu


Prions

Infectious proteins

Kuru

CJD

Mad cow disease

Scapie

1997 Nobel Prize

Prusiner


zeitgeist777

open your mind

Ebola virus

https://zeitgeist77.wordpress.com/


Transmission Route


http://www.cdc.gov/


Zika Time lines

1947

Scientists identify a new virus in a rhesus monkey in the Zika forest of Uganda - named as the Zika virus.


Pathogenecity

Staphylococcus aureus

Staphylococcus epidermidis

Streptococcus pneumoniae

Vibrio cholerae

Rhodospirillium rubrum

Bacillus subtilis

Micrococcus luteus

Escherichia coli

Bacillus anthrasis

Salmonella enteridis

Streptococcus pyogenes

Steptococcus lactis

Streptococcus faecalis

Erlichia canis

Campylobacter jujuni

Helicobacter pylori

Enterobacter aerogenes


How to Study Medical Microbiology?

Fundamentals of Microbiology

Bacteriology

Virology

Mycology

•Biological Properties

•Morphology, identification,

•Antigenic structure

•Pathogenesis and Pathology

•Clinical findings

•Diagnostic Laboratory Tests

•Immunity

•Treatment & Prevention

•Epidemiology & Control


Assessments

Participation

Quizzes & assignments

Final Examination

5%

10%

85%


Question

Classification of microorganisms

Koch’s Postulates


Web Resources PubMed: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=

PubMed

National Center for Biotechnological Information

http://www.ncbi.nlm.nih.gov

WHO: http://www.who.int/en/

US CDC: http://www.cdc.gov

UNAIDS: http://www.unaids.org/EN/default.asp

NIH：http://www.nih.gov

China CDC:http://www.chinacdc.net.cn

China Ministry of Health: http://www.moh.gov.cn


Some of the figures used in this chapter

have been collected from a variety of

media resources. Because of workload

is heavy, we did not make annotations

of all sources point-by-point.

If you have questions, contact ,e please.

Thank you for your understanding!

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