Introduction to Bacteriology

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The study of microscopic organisms (microbes), that are either single celled (unicellar), a cell cluster or no cells at all (acellular)

Microbiology

Microscopic Organisms

Microbes

Single celled

Unicellular

No cells at all

Acellular

• These are misfolded protein particle • It causes Neurodegenerative diseases

Prions

• It can be either a DNA or RNA • A ____ cannot contain both genetic codes • It could be: Double Stranded or Single Stranded • It can be enveloped or non-enveloped type.

Virus

An acellular infectious agents

Prions, Virus

Unicellular o Simple type of structure

Prokaryotic Cells

• Complex • It has the ability to become multi- cellular organism.

Eukaryotic Cells

It has no nucleus, no organelles, cell is made up of peptidoglycan, it makes binary fission

Prokaryotic Cells

It has: Nucleus, has organelles if it has cell wall it contains cellulose and chitin mitosis

Eukaryotic cells

A diverse group of Eukaryotic organisms that includes yeasts, mushrooms and molds.

Fungi

Types of Fungi

Yeast, Molds, Mushrooms

Single celled fungi that reproduces through budding.

Yeast

Example of Yeast

Candida Albicans

Multicellular fungi that grows hyphae, specifically filamentous hyphae, and forms a network called mycelium

Molds, Virus

Example of Molds

Aspergillus sp

The fruiting bodies of certain ,fungi, typically larger and more complex than molds and yeasts.

Mushrooms

A special type of fungi that can exist in two different forms, depending on their environmental

Dimorphic Fungi

Occurs at body temperature (37°C).  Grows in human tissues; as single-celled yeasts inside the hosts  Example: Histoplasma capsulatum inside the body.

Yeast Form

Occurs at cooler temperatures (25°C). They grow as multicellular molds with hyphae in soil or other external environments. Example: Histoplasma capsulatum in the soils.

Mold Form

A single-celled microorganisms that can exists as an independent organism.  1-20 μm or even larger.  Shapes: (Sphere, Rods and Spirals)  Spatial (Single cells, Chains, or even Cluster)  Binary Fission  Bacterial Cell Wall Forms: Gram Positive and Gram negative (+/-)

Bacteria

These are usually the categorization of organisms into taxonomic groups. (eg, based on its biochemical, physiologic, genetic and morphologic properties.)

Classification

Naming of an organism by international rules according to its characteristics.

Nomenclature

Practical use of classification scheme to: Isolate and differentiate the desirable organisms from the undesirable ones.  Isolate and distinguish the causative agents.

Identification

MICROBIAL TAXONOMY It has three distinct areas:

Classification, Nomenclature, Identification

(Usually its abbreviated as sp..., singular, or spp.., plural) o It is the most basic identification of taxonomic groups or the collection of bacterial strains.

Species

A subgroup within a species.  This includes:  Biotype  Serotype  Genotype

Species

(Plural: Genera) It is composed of various species with common characteristics.

Genus

Composed of the similar genera.

Family

GENUS DESIGNATION - First letter is always? Example: (“S”. aureus)

Capital

SPECIES DESIGNATION - First letter is always? Example: (S. “p” neumoniae)

Lowercase

Species Designation: When this is referred to as a group, names are neither capitalized nor underlined.  Example: staphylococci, streptococci

Informal

A group of microorganisms that share the same biochemical properties

Biogroup

A group of microorganism having the similar antigens

Serogroup

The proper word for the name of the species

Epithet

The altered or variant microorganism within the same species.

Strain

The prokaryotic strain that differs morphologically from the other strains.

Morphovar / Morphotype

Modern system of bacterial classification and identification (Phylogenetic, Phenotypic and Genotypic characterization)

Polyphaspic Taxonomy

Three categories to consider in a bacterial structure:

External structures, such as the Appendages (Flagella, Fimbriae, Pili, and Glycocalyx), Cell Envelope, these are the cell walls and its membranes., Internal structures, includes the chromosomes, plasmids, cytoplasmic granules and the inclusions.

These coating are usually made of molecules found on the cell wall. It has glycoprotein and glycolipids.

Glycocalyx

It is tightly attached and organized. The gel is firmly adherent to cell envelope.

Capsule

It is loosely organized and attached. The gel is easily washed off from the cell envelope.

Slime Layer

Flagella, the organ of locomotion in bacterial cell and consists of three parts:

Filament, Hook, Basal Body

The protein that makes up the organ.

Hook

Bacteria with no flagellum.

Atrichous

Bacteria with single polar flagellum

Monotrichous

Bacteria with a bunch of flagella at one pole.

Lophotrichous

Bacteria with flagella at both poles.

Amphitrichous

Bacteria with flagella all over their surface.

Peritrichous

Also known, "Axial Filament " - It is the organ of motility found in periplasmic space of spirochetes.

Endoflagella

These are fine, hair-like bristles made from proteins that are found on the cell’s surfaces. - Its function is to adhere to other cell’s surface.

Fimbriae

A hair like structure composed of protein called Pilin. There are two types based on function: o Common Pili o Sex Pili

Pili

It is the external covering outside the cytoplasm. Maintains cell integrity .

Cell Envelope

A multi-layered structured that is composed of N-acetyl muramic acid and N-Acetyl Glucosamine back bones cross-linked with a peptide chain and pentaglycine bridge.  PEPTIDOGLYCAN = The most primary component

Cell Wall

It accounts for 30 % of the dry weight of the bacterial cell. The phospholipid bilayer is embedded with proteins.  Most components are comprised with: o 60% protein o 20 - 30% lipids o 10 - 20 % carbohydrates

Cell Membrane

Internal Structures

Chromosomes, Plasmids, Ribosomes

An extra chromosomal genetic material . Integrated into the chromosome  Duplicated and passed on to the off springs.

Plasmids

The ________ monomer is 70s with two subunits, (30s and 50s) small and large.

Ribosomes

A resting structure formed on the insides of some bacteria. It is their means of survival when moisture or nutrient supply is low.

Endospores

Bacterial MORPHOLOGY THREE BASICS SHAPES OF BACTERIA:

Coccus, Bacillus, Spirillum

Arrangement of bacteria:

Diplo, Staphylo, Strepto, Coccobacilli, Tetrad, Sarcinae

REQUIREMENTS FOR GROWTH

Nutrients (Carbon; Hydrogen; Oxygen; Nitrogen; Phosphate and Ions), Temperature, pH, Aeration, NaCl requirements

They produce their own food : CO2+ H2O + Inorganic salts Grow using CO2 as its only source of carbon atom. Obtains energy through: Photosynthetically (Phototrophs) Oxidation of inorganic compounds (Chemolithotrophs)

Autotrophs (Litotrophs)

Requires more complex substances for growth .  Organic source of carbon.  Obtain energy via oxidation or fermentation of organic substances.

Heterotrophs

Psychrophilic (Cryophilic) and Psychrotrophs: grow best at 0-20˚C

Listeria monocytogenes and Yersinia Enterocolitica

Grow best at 20-45 ˚C o Most pathogenic bacteria

Mesophiles

Thermophiles: grow best at 50-125 ˚C

Bacillus stearothermophilus and Thermus aquaticus

Capable of surviving in unfavorable conditions (temperature or pressure)

Extremophiles

Extremophiles: capable of surviving in unfavorable conditions (temperature or pressure)

Bacillus infernus

Optimal pH:

7.0-7.5

Carbon Dioxide Requirements: Require increased CO2 Most aerobes and facultative anaerobes require only 0.03% CO2

Capnophiles

Other requirements, such as salt and pressure: Requires increased NaCl concentration

Halophiles

Grow rapidly in high-pressure environment

Barophiles

Some bacteria could with stand heating and boiling. These are called?

Endospores

Endospores, that are commonly observed in the genera such as?

Clostridium, Bacillus

The organ of locomotion

Flagella

It is a process by which living organisms are produced from other living organisms.

Biogenesis

A hair like structure composed of protein called?

Pilin

Pili are typically longer and fewer in number than fimbriae.

True

Cell Envelope: It is composed of two basic layers

Cell Wall, Cell Membrane

Regulates the transport of nutrients and wastes products into the cell.

Cell Membrane

Functions of Cell Membrane:

Synthesis of cell wall components, Assists in DNA replication secretes proteins, Carries on electron transport system, Provides site for energy reactions, nutrient processing and synthesis transport in and out of the cell.

DNA is tightly coiled, aggregated in a dense area called?

Nucleoid

Requires O2 for growth

Aerobes

2- 10% oxygen for growth

Microaerophiles

Obligate/ No oxygen for growth

Anaerobes

Most clinically significant - Generally, do not need O2 but grow best w/ O2

Facultative anaerobes

Survive in the presence of oxygen but will be unable to perform metabolic processes.

Aerotolerant anaerobes

Shapes: Spherical or ovoid bacterium

Coccus

Shapes: Rod-shaped bacterium

Bacillus

Shapes: helical or corkscrew-shaped bacterium

Spirillum

Example: Histoplasma capsulatum inside the body.

Yeast Form

Isolate and distinguish the causative agents.

Identification

It is the most basic identification of taxonomic groups or the collection of bacterial strains.

Species

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