L1. Introduction to Bacteriology

Linnaean Taxonomy

A classification system for organisms based on hierarchical ranks.

Bacteriology

The study of single-celled microorganisms that lack a true nucleus.

Domain

Bacteria.

Kingdom

Prokaryotae.

Division or Phylum

Gracilicutes.

Class

Scotobacteria.

Order

Eubacteriales.

Family

Enterobacteriaceae.

Genus

Escherichia.

Species or Epithet

coli.

Subtype

Escherichia coli O157:H7.

Subspecies (subsp)

A further division of species.

Serovarieties (serovar)

Based on serologic test result differences.

Biovarieties (biovar)

Based on biochemical test result differences.

Binomial system

A two-part naming system for species.

Koch's Postulates

A series of criteria to establish a causative relationship between a microbe and a disease.

Phenotypic characteristics

Readily observable traits of an organism.

Genotypic characteristics

Genetic make-up of an organism based on their DNA and RNA structure and homology.

Prokaryotes

Cells that lack a true nucleus and membrane-encased organelles.

Eukaryotes

Cells with a true nucleus and membrane-encased organelles.

Archaebacteria

Bacteria that grow under extreme environmental conditions.

Father of Medicine

Hippocrates.

Father of Microbiology

Antonie van Leeuwenhoek.

Father of Immunology

Edward Jenner.

Aseptic Surgery

Founded by Joseph Lister, important in Bacteriology.

Gram's Staining

A method employed for microscopic bacterial cell differentiation.

Bordetella pertussis

Causative agent for whooping cough discovered by Jules Bordet.

Kleb's Loeffler's bacilli

Cultivated by Friedrich Loeffler.

Penicillin

Discovered from mold 'Penicillum nolatum' by Alexander Flemming.

Genome

Located in the nucleoid at the mesosome.

Taxonomy

Orderly classification and grouping of organisms into 'taxa' or categories.

Taxon

Means 'arrangement'.

Nomos

Means 'law'.

Nomenclature

The naming of microorganisms according to established rules and guidelines set forth in the International Code of Nomenclature of Bacteria.

Reproduction

Can be asexual or sexual and asexual.

Identification

The process by which a microorganism's key features are delineated.

Membrane-bound organelles

Present in all eukaryotic cells; absent in prokaryotic cells.

Lysosomes

Contain hydrolytic enzymes and are absent in all prokaryotic cells.

Endoplasmic Reticulum

Present in all eukaryotic cells; absent in all prokaryotic cells.

Mitochondria

Present in all eukaryotic cells; present in most prokaryotic cells.

Ribosomes

Sites of protein synthesis; present in all cells.

Ribosome Size

70S = 50S and 30S; 80S = 60S and 40S.

Flagella

Made up of a protein called flagellin; classification according to number and arrangement of the flagella on bacterial cell.

Glycocalyx

Present as capsule or slime layer.

Pili

Non-motile, long, hollow protein tubes made up of pilin that connects two bacterial cells.

Fimbriae

Non-flagellar, sticky, proteinaceous, hair-like appendages that aid in adhesion to tissues and surfaces.

Cilia

Present in some eukaryotic cells; absent in prokaryotic cells.

Plasmids

Small circular molecules of DNA commonly found in Gram Negative bacteria.

Cell Wall

Composed of peptidoglycan in bacteria.

Sterols

Absent except in the mycoplasma; present in eukaryotic cells.

NUCLEUS

has chromosomes which contains DNA. They are covered with basic proteins called histones. It is bounded by a bilayered lipoprotein membrane known as the nuclear membrane.

NUCLEOLUS

round, refractile body which is the site of ribosomal RNA synthesis. It is located within the nucleus.

ENDOPLASMIC RETICULUM

A system of membranes that occur throughout the cytoplasm.

ROUGH ENDOPLASMIC RETICULUM

Covered with ribosomes which gives it a "rough" appearance. It is the site of protein synthesis.

SMOOTH ENDOPLASMIC RETICULUM

No ribosomes. It doesn't synthesize proteins but it synthesizes phospholipids.

GOLGI APPARATUS

Modify and package proteins sent by the rough endoplasmic reticulum.

RIBOSOMES

Where protein synthesis occurs.

MITOCHONDRIA

Main site of energy production.

LYSOSOME

Contains hydrolytic enzymes for degradation of macromolecules and microorganisms within the cells.

MESOSOMES

point of attachment of chromosomes.

PEROXISOMES

Break down hydrogen peroxide.

PLASMA MEMBRANE

phospholipid bilayer.

CILIA

Short projections that extend from the cell surface and used for locomotion.

COCCI

Spherical in shape. Singular: Coccus.

CELL WALL (MUREIN LAYER)

Provides rigidity and strength to the exterior of the cell.

DIPLOCOCCI

Cocci in pairs.

STREPTOCOCCI

Cocci in chains.

STAPHYLOCOCCI

Cocci in clusters.

SPIROCHETES

Spiral/helical with a long axis that bends when in motion.

FUSIFORM BACILLI

Bacilli in short rods or ovals.

VIBRIO

Curve rod-shaped, comma shaped.

PLASMOLYSIS

A cell in a saline solution shrinks because water passes out.

PLASMOPTYSIS

A cell in distilled water bursts.

CALCIUM DIPICOLINATE

A composition of their inclusion bodies.

Gaffkya tetragena

Representative organism of Tetrads.

Sarcina lutea

Representative organism of Sarcina.

Cocci

All cocci are gram positive except Neisseria, Veillonella, and Moraxella group.

Bacilli

All bacilli are gram negative except Bacillus, Clostridium, Mycobacterium, Corynebacterium, and Listeria.

Bacillus

Singular form of bacilli; rod shaped.

Nocardia

A type of bacilli.

Erysipelothrix

A type of bacilli.

Lactobacillus

A type of bacilli.

Kurthia

A type of bacilli.

Rothia

A type of bacilli.

Spiral organisms

Very hard to stain but they are gram negative.

Non-sporing snapping diplobacilli

If the organism appears in V-shaped.

Non-sporing slipping diplobacilli

If the organism appears parallel to each other.

Lactobacillus acidophilus

Acid-loving; requires pH 3.0; tomato juice agar is used.

Vibrio

Alkali-loving; requires pH 8-10; use Alkaline Peptone Water as a culture medium.

Bacterial replication

Bacteria multiply by binary fission, producing 2 identical daughter cells.

Lag phase

Involves little or no growth.

Log/Exponential phase

Maximum rate of bacterial multiplication; most susceptible to antimicrobials.

Plateau/Stationary phase

Number of bacteria alive is equal to the number of dead bacteria.

Decline phase

Increase in number of dead bacteria.

Bacterial transformation

Free or naked DNA found in the environment is taken up by a bacterial cell.

Bacterial transduction

A virus injects DNA into the bacterial cell.

Lytic cycle

The replication of the bacterial chromosome is disrupted.

Lysogenic cycle

The bacteriophage DNA is incorporated into the bacterial genetic material.

Bacterial conjugation

DNA is transferred from one cell to another via sex pili.

Lithotroph/Autotroph

Carbon source is from Carbon dioxide.