Intro to Bacteriology

Nucleoid, bound, cytoplasm, membrane, wall, capsule, pili, flagella

Bacteria general characteristics

• do NOT have a nucleus but instead have a “__ region”

• No membrane-__ organelles, do have __, have cell __

• External structures - cell __, __, __, __

1, Chromosome, separation, synthesis

Bacterial cell/plasma membrane

• There is _ (#) bacterial __ attached and plays role in chromosomal __ during division

• DNA __ occurs at bacterial chromosome

No, exotoxins, purple

Gram (+) Bacterial cell wall

• __ (has/no) lipopolysaccharide

• May produce wide variety of __ but NO endotoxin

• __ (color) stain

Has, endo, pink

Gram (-) Bacterial cell wall

• __ (has/no) lipopolysaccharide

• Only produces __toxins

• __ (color) stain

Peptidoglycan, lysosome, transpeptidase

Both gram + and - have structural component __

• Carbohydrate chains composed of N-acetyl glycosamine and N-acetyl muraminic acid

  • Can be broken down by organelle __

• Cross linked by short peptides, named __

Thick, osmotic lysis, teichoic

Structure of Gram (+) cell walls

• Has __ (thin/thick) peptidoglycan layer outside bacterial cell membrane

  • Fairly rigid matrix protects cell from __ __

• Also contains __ acid

Thin, second, LPS, endotoxin, O

Structure of Gram (-) cell walls

• Has __ (thick/thin) peptidoglycan layer

• Outside structure is a __ membrane

  • Contains __ lipids

  • Toxic to humans (as an __)

  • _ antigen side chain on LPS is major surface antigen

Periplasmic Space

Space between thin peptidoglycan layer and outer membrane (in gram - bacteria)

Lipid A, polysaccharide, O antigen

3 components of LPS

• __ _ - Phospholipid

• Core __

• _ __ polysaccharide - facing outermost surface

TLR4

Lipid A is recognized by __ (Receptor) and stimulates innate immune system “over response” ; in gram (-)

Flagella

Provide motility, protein structure, and found in many bacteria (not all)

Pili (fimbriae)

Protein structure forming hollow tube

Common pili

Allow bacteria to attach to cell surfaces during infection and are important virulence factor

F pili

Involved in bacterial conjugation in gram - bacteria “sex pili”

Hydrophilic, slime, wall

Bacterial capsules

• Not in all bacteria

• __ (hydrophilic/hydrophobic) gel (thick); called “__ layer”

• External to cell __ and composed primarily of polysaccharide

Antigens, phagocytosis

Bacterial capsules help bacteria evade immune responses by:

• Masking __

• Inhibiting __ by macrophages/neutrophils

Coccus, bacillus, coccobacillus, spirochete

Bacterial Shapes

__ = round

__ = rod/log

__ = oval

__ = spiral or corkscrew

Sporulation, dormant, hostile, reproductive

__ are bacterial production of spores that are environmentally stable

• __ protective structures produced in a “__” environment to allow survival of individual bacterium

• These are NOT __ structures

Speed, versatility, ATP

Bacteria utilize metabolic pathways for: 

• __ - Metabolize nutrients much more quickly than eukaryotic cells

• __ - Different species have evolved ability to use varied array of compounds as energy source and nutrition

• Bacteria may use fermentation and/or respiration pathways to generate __

O2, greater

Respiration metabolic pathway with bacteria

Glucose → Glycolysis to pyruvate → Electron acceptor __ → __ ATP formed

Organic molecule, less

Fermentation metabolic pathway with bacteria

Glucose → Glycolysis to pyruvate → Electron acceptor __ __ → __ ATP formed

Facultative anaerobe

Bacteria that can grow either with or without oxygen

Nutrient media

Culture is combination of nutrients for bacterial metabolism

Selective media

Culture contains chemical additives, anti-microbials to inhibit growth of contaminants

Indicator media

Culture contains ingredients to demonstrate biochemical or other characteristic features of pathogen (Carbs, pH indicators, RBCs)

metabolism, fermentation, pyruvate

Products of __ are especially useful in bacteria identification if unusual __ pathways are involved

• Fermentation of __ by different microorganisms results in different end products

Lag phase, exponential phase

Bacterial growth stages

The __ __ is adjustment to new environment

The __ __ is rapid logarithmic growth

Stationary phase, death phase

Bacterial growth stages

The __ __ is when nutrients are decreased

The __ __ is when nutrients depleted and toxic waste accumulation

Toxins, enzymes

Production of certain __ (product) and __ (proteins) by species of bacteria can be useful for identification in the lab

Hemolysis

Lysis of red blood cells noted when bacteria are cultured on blood agar

hemolysin, streptococcus

In hemolysis

• Result of __ (pore-forming toxin) produced by bacteria

• Can aid in identifying ___ species (bacteria type)

Alpha, greenish, methemoglobin, beta, clear

• __ hemolysis: Incomplete hemolysis (area around colony is __-color)

  • Result of bacterial H2O2 converting hemoglobin to __

• __ hemolysis: Complete lysis of RBCs (__ zone around colony)

Catalase, bubbles

__ enzyme breaks down H2O2 to produce water and O2 → forms __ (reaction)

Coagulase, clotting

__ enzyme converts fibrinogen in blood plasma to fibrin; activates __

Staph, strep, virulence

Both of catalase and coagulase are important in identification of __ and __ species of bacteria

• Both are __ factors that benefit bacteria

Staphyloc, streotoc, microbiota

Catalase and coagulase tests are useful for:

• Distinguishing __ and __ strains from a skin or throat sample

• All round and purple on gram stain

• These are very common bacterial strains, some part of the __