1. PENDAHULUAN
2. PENGGOLONGAN MIKROORGANISME
3. STRUKTUR DAN FUNGSI SEL MIKROORGANISME
4. PERTUMBUHAN MIKROORGANISME
5. GENETIKA MIKROORGANISME
6. BIOENERGETIKA MIKROORGANISME
7. PENGENDALIAN PERTUMBUHAN MIKROORGANISME
8. INTERAKSI DAN PENYEBARAN MIKROORGANISME
9. PERANAN MIKROORGANISME
MIKROBIOLOGI
MIKROBIOLOGI
DASAR
I.
PENDAHULUAN
II.
EVOLUSI DAN KERAGAMAN MIKROBA
III.
TINGKATAN TAKSONOMI
IV. SISTEM KLASIFIKASI
V.
KARAKTERISTIK UTAMA YANG DIGUNAKAN DALAM
TAKSONOMI
VI. PERKIRAAN (
ASSESSING)
FILOGENI MIKROBA
VII. DIVISI UTAMA ORGANISME
VIII. BERGEY’S MANUAL OF SYSTEMATIC BACTERIOLOGY
IX. GARIS BESAR FILOGENI DAN KERAGAMAN PROKARIOT
X.
MENGENAL LEBIH DEKAT ANGGOTA DUNIA MIKROBA
A. ARCHAEA
B. BACTERIA
C. FUNGI
D. ALGAE
E. PROTOZOA
F. VIRUS
1. PERKEMBANGAN AWAL VIROLOGI
2. GENERAL PROPERTIES OF VIRUSES
3. THE CULTIVATION OF VIRUSES
4. VIRUS PURIFICATION AND ASSAYS
5. THE STRUCTURE OF VIRUSES
6. PRINCIPLES OF VIRUS TAXONOMY
7. BACTERIOPHAGES
8. VIRUSES OF EUCARYOTES
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
1) Morphology - most important characteristic for classification
2) Physical and chemical nature of virion, especially nucleic acids, are also
important for classification
8. VIRUSES OF EUCARYOTES
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
b. Reproduction of Animal Viruses
1) Adsorption of virions
2) Penetration and uncoating
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
c. Cytocidal Infections and Cell Damage
1) Viruses often damage their host cells, in some cases causing cell death; if
death occurs the infection is cytocidal
2) Seven mechanisms for causing cell damage have been identified
i. Inhibition of host DNA, RNA, and protein synthesis
ii. Lysosome damage, leading to release of hydrolytic enzymes into the cell
iii. Plasma membrane alteration, leading to host immune system attack on the cell or to cell fusion
iv. Toxicity from high viral protein concentrations
v. Formation of inclusion bodies that may cause direct physical disruption of cell structure
vi. Chromosomal disruptions
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
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8. VIRUSES OF EUCARYOTES
d. Virus Infections
1) Persistent infections-long lasting infections
i. Chronic infection-virus is usually detectable, but clinical symptoms are mild or absent for long periods
ii. Latent infections-virus stops reproducing and remains dormant for a period before becoming active again; during latency, no symptoms, antibodies or viruses are detectable
2) Causes of persistence and latency are probably multiple
i. Viral genome integrates into host chromosome ii. Virus becomes less antigenic
iii. Virus mutates to less virulent and slower reproducing form
iv. Deletion mutation produces defective interfering (DI) particles, which cannot reproduce but slow normal virus reproduction and thereby reduce host damage and establish a chronic infection
3) Slow virus infections
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
e. Viruses and Cancer
1) Cancer
a disease where there is abnormal cell growth (neoplasia) and the
spread of the abnormal cells throughout the body (metastasis)
i. Tumor - a growth or lump of tissue; can be benign (nonspreading)
or malignant (cancerous)
ii. Carcinogenesis is a complex, multistep process that involves a
triggering event and the activity of oncogenes
2) Viral etiology of human cancers
is difficult to establish because Koch’s postulates can only be satisfied
8. VIRUSES OF EUCARYOTES
e. Viruses and Cancer
3) Viruses and human cancers
i. Epstein-Barr virus (EBV)-a herpesvirus that may cause:
Burkitt’s lymphoma; found mostly in central and western Africa
Nasopharyngeal carcinoma; found in Southeast Asia
Infectious mononucleosis; found in the rest of the world
Evidence suggests that host infection with malaria is necessary for
EBV to cause Burkittís lymphoma; this is supported by the low
incidence of Burkittís lymphoma in the U.S. where there is almost
no malaria
ii. Hepatitis B virus may be associated with one form of liver cancer
iii. Human papillomavirus has been linked to cervical cancer
8. VIRUSES OF EUCARYOTES
e. Viruses and Cancer
4) Viruses may cause cancer by a variety of mechanisms
i. Virus may carry one or more cancer-causing genes (oncogenes)
ii. Viruses may produce a regulatory protein, which activates cell division
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
f. Plant Viruses
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
f. Plant Viruses
1) Have not been well studied, primarily because they are difficult to cultivate
and purify
2) Virion morphology does not differ significantly from that of animal viruses or
bacteriophages; most are RNA viruses
3) Plant virus taxonomy - classified on the basis of nucleic acid type,
strandedness, capsid symmetry, size, and the presence or absence of an
envelope
4) Plant virus reproduction (using tobacco mosaic virus as an example)
i. The virus uses either a cellular or a virus-specific RNA-dependent RNA polymerase
ii. The virus produces proteins, which then spontaneously assemble iii. Viral spread is through the plant vascular system
8. VIRUSES OF EUCARYOTES
f. Plant Viruses
5) Transmission of plant viruses-process is complicated by the tough walls that
cover plant cells
i. Some may enter only cells that have been mechanically damaged
ii. Some are transmitted through contaminated seeds, tubers, or pollen
iii. Soil nematodes can transmit viruses while feeding on roots
iv. Some may be transmitted by parasitic fungi
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
g. Viruses of Fungi and Algae
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
g. Viruses of Fungi and Algae
1) Most viruses of higher fungi (mycoviruses) are dsRNA viruses that cause
latent infections
2) Viruses of lower fungi are dsRNA or dsDNA viruses that cause lysis of
infected cells
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
f. Plant Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
h. Insect Viruses
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
h. Insect Viruses
1) Members of at least seven virus families are known to infect insects
2) Infection is often accompanied by formation of granular or polyhedral
inclusion bodies
3) May persist as latent infections
4) Current interest in most insect viruses focuses on their use for biological
pest control; they have several advantages over chemical toxins:
i. They are invertebrate-specific and, therefore, should be safe
ii. They have a long shelf life and high environmental stability
8. VIRUSES OF EUCARYOTES
a. Classification of Animal Viruses
b. Reproduction of Animal Viruses
c. Cytocidal Infections and Cell Damage
d. Virus Infections
e. Viruses and Cancer
f. Plant Viruses
g. Viruses of Fungi and Algae
i. Viroids and Prions
SUBPOKOK BAHASAN
8. VIRUSES OF EUCARYOTES
i. Viroids and Prions
1) Viroids
i. Circular ssRNA molecules
ii. No capsids
iii. Cause diseases in plants
iv. Do not act as mRNAs
8. VIRUSES OF EUCARYOTES
i. Viroids and Prions
2) Prions
i. Proteinaceous infectious particles (PrP) that are not associated with a nucleic acid
ii. Genes have been identified in normal animal tissue that encode PrP
It is hypothesized that abnormal PrP causes prion diseases by inducing a change from the normal conformation of the cellular PrP to the abnormal form
This new abnormal PrP then causes other normal cellular PrP molecules to change to the abnormal form
iii. Cause progressive, degenerative central nervous system disorders
SCRAPIE in sheep and goats
BOVINE SPONGIFORM ENCEPHALOPATHY (mad cow disease)
KURU (found only in the Fore, an eastern New Guinea tribe that practice ritual cannibalism)
Common Cold web site
(http://www.commoncold.org/)
All the Virology on the WWW
(http://www.tulane.edu/~dmsander/garryfavweb.html)
The Big Picture Book of Viruses
(http://www.tulane.edu/~dmsander/Big_Virology/BVHomePage.html)
Electron microsopic images of Human Viruses
(http://www.uct.ac.za/depts/mmi/stannard/linda.html)
Linda Stannard's "illustrated tutorial on the morphology of most of the clinically significant viruses".
Institute for Molecular Virology
required by the cell for normal cell functioning (e.g., hormone receptors, chemokine receptors)
modes of entry
i. Changes in capsid structure leads to entry of nucleic acid into host
ii. Fusion of viral envelope with the host cytoplasmic membrane results in deposition of the nucleocapsid core within the cell
iii. Engulfment of virus within coated vesicles (endocytosis); lysosomal enzymes and low endosomal pH often trigger the uncoating process
to taking over host cell; this may involve halting synthesis of host DNA, RNA, and protein or in some cases these processes may be stimulated
b) Later, viral DNA replication occurs, usually in the nucleus c) Some examples
i. Parvoviruses (ssDNA)-have a very small genome with overlapping genes; use host enzymes for all biosynthetic process
ii. Herpesviruses (dsDNA)-host RNA polymerase is used to transcribe early genes; DNA replication is catalyzed by viral DNA polymerase
iii. Poxviruses (dsDNA)-viral RNA polymerase synthesizes early mRNA; one of the early gene products is viral DNA polymerase, which replicates the viral genome
i. +strand RNA viruses use their genome as mRNA
ii. -strand RNA viruses use viral RNA-dependent RNA polymerase (transcriptase) to synthesize mRNA, using the genome as the template
iii. dsRNA viruses use viral RNA-dependent RNA polymerase to synthesize mRNA
b) Replication in RNA viruses (except retroviruses)
i. ssRNA viruses use viral replicase (an RNA-dependent RNA polymerase) to convert ssRNA into dsRNA (replicative form); replicative form serves as template for genome synthesis
ii. dsRNA viruses-viral mRNA molecules associate with special proteins to form a large complex; replicase then uses these mRNA molecules as templates for synthesis of dsRNA genome
c) For dsRNA viruses and -strand RNA viruses, the viral RNA-dependent RNA polymerase functions both as the transcriptase and the replicase; the mode of action depends on associated proteins and other factors
d) Retroviruses make a dsDNA copy (called proviral DNA) using the enzyme reverse transcriptase i. The proviral DNA is integrated into the host chromosome
viral late genes
b) Empty procapsids are produced c) Nucleic acid is inserted
b) Enveloped viruses are usually released by the following mechanisms:
i. Virus-encoded proteins are incorporated into plasma membrane (some viruses use nuclear membrane, endoplasmic reticulum, Golgi apparatus, or other membranes)
ii. Nucleocapsid buds outward, forming the envelope during release
