Searching...
Flashcards in this deck (76)
  • Bacteria are organized in a hierarchy: Kingdom, Phylum, Class, Order, Family, Genus, and Species.

    taxonomy bacteria
  • A useful mnemonic for the taxonomic classification of bacteria is: 'King Philip Came Over For Good Spaghetti'.

    mnemonic taxonomy
  • Bacterial names are in Latin, with the Genus capitalized and the species in lowercase.

    naming bacteria
  • The full species name of bacteria is italicized in print, e.g., Staphylococcus aureus.

    naming bacteria
  • Key characteristics used for classification include morphology, metabolic phenotypes, and molecular techniques.

    identification bacteria
  • Morphology includes the bacterium's shape (e.g., cocci, rod, branching), Gram stain result, presence of endospores, and motility.

    morphology bacteria
  • The quickest modern method for bacterial identification is sequencing the 16S rRNA gene.

    molecular_techniques identification
  • The gene is amplified and its sequence is compared to a database like the Ribosomal Database Project for a match.

    molecular_techniques identification
  • Clinically important Gram-Positive Cocci include Staphylococcus aureus (clusters) and Streptococcus pneumoniae (pairs/chains).

    bacteria gram-positive
  • Clinically important Gram-Positive Rods (Bacilli) include Bacillus anthracis (spore-forming), Listeria, and Clostridium (spore-forming).

    bacteria gram-positive
  • Clinically important Gram-Positive Branching Filaments include Actinomyces israelii.

    bacteria gram-positive
  • Clinically important Gram-Negative Cocci include Neisseria meningitidis (diplococci).

    bacteria gram-negative
  • Clinically important Gram-Negative Rods (Bacilli) include Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Klebsiella, and Helicobacter pylori.

    bacteria gram-negative
  • A key way to differentiate bacteria is by their cell wall structure, revealed by the Gram stain.

    bacteria identification
  • Gram-Positive Bacteria have 2 layers: an inner membrane and a thick (60-100%) peptidoglycan layer.

    gram-positive cell-wall
  • Gram-Negative Bacteria have 3 layers: an inner membrane, a thin (5-10%) peptidoglycan layer, and an outer membrane.

    gram-negative cell-wall
  • Endotoxin (LPS) is absent in Gram-Positive Bacteria and present in the outer membrane of Gram-Negative Bacteria.

    endotoxin gram-positive gram-negative
  • The Gram stain helps differentiate bacteria based on their cell wall structure.

    gram-stain identification
  • The Gram stain result indicates whether bacteria are Gram-Positive or Gram-Negative.

    gram-stain identification
  • The thick peptidoglycan layer in Gram-Positive Bacteria contributes to their staining characteristics.

    gram-positive cell-wall
  • Lipoteichoic Acid (LTA) is present in Gram-positive bacteria and absent in Gram-negative bacteria.

    microbiology bacteria lipoteichoic_acid
  • Porin channels are absent in Gram-positive bacteria and present in the outer membrane of Gram-negative bacteria.

    microbiology bacteria porin_channels
  • The periplasm in Gram-positive bacteria is small or absent, while in Gram-negative bacteria it is present and can accumulate enzymes like ẞ-lactamase.

    microbiology bacteria periplasm
  • Staphylococcus aureus is a Gram-positive bacterium characterized by cocci in clusters and is catalase-positive.

    microbiology bacteria staphylococcus_aureus
  • Staphylococcus aureus is a common cause of hospital-acquired infections, skin abscesses, and Toxic Shock Syndrome.

    microbiology bacteria virulence_factors
  • Streptococcus pneumoniae is a Gram-positive bacterium that appears as cocci in pairs or chains.

    microbiology bacteria streptococcus_pneumoniae
  • Streptococcus pneumoniae is catalase-negative and a-hemolytic.

    microbiology bacteria virulence_factors
  • The polysaccharide capsule of Streptococcus pneumoniae is a major virulence factor that impairs phagocytosis.

    microbiology bacteria virulence_factors
  • Bacillus anthracis is a Gram-positive bacterium with large rods that have squared ends.

    microbiology bacteria bacillus_anthracis
  • Bacillus anthracis forms endospores that are centrally located and causes anthrax.

    microbiology bacteria virulence_factors
  • Bacillus anthracis is considered a potential agent of bioterrorism.

    microbiology bacteria bioterrorism
  • The clinical significance of Staphylococcus aureus includes its role in hospital-acquired infections and Toxic Shock Syndrome.

    microbiology bacteria clinical_significance
  • Streptococcus pneumoniae is a leading cause of pneumonia, meningitis, and ear infections.

    microbiology bacteria clinical_significance
  • The distinguishing features of Staphylococcus aureus include golden colonies and being coagulase-positive.

    microbiology bacteria distinguishing_features
  • The virulence factors of Streptococcus pneumoniae include its polysaccharide capsule and being optochin-sensitive.

    microbiology bacteria virulence_factors
  • Bacillus anthracis is characterized by its ability to form endospores and its association with anthrax.

    microbiology bacteria characteristics
  • The Gram stain and shape of Staphylococcus aureus is G+ cocci in clusters.

    microbiology bacteria staphylococcus_aureus
  • The Gram stain and shape of Streptococcus pneumoniae is G+ cocci in pairs or chains.

    microbiology bacteria streptococcus_pneumoniae
  • The Gram stain and shape of Bacillus anthracis is G+ large rods with squared ends.

    microbiology bacteria bacillus_anthracis
  • The bacterium Actinomyces israelii is characterized as G+ branching rods and is anaerobic.

    bacteria actinomyces
  • Actinomyces israelii forms sulfur granules in infections and is part of the normal flora that can cause actinomycosis.

    bacteria infections
  • Neisseria meningitidis is a G- diplococcus that is aerobic and has a capsule.

    bacteria neisseria
  • Neisseria meningitidis can cross the blood-brain barrier to cause meningitis.

    bacteria meningitis
  • The diagnosis of Neisseria meningitidis is made by Gram stain of cerebrospinal fluid (CSF).

    bacteria diagnosis
  • Escherichia coli is a G- rod that is a facultative anaerobe and is positive for lactose fermentation.

    bacteria escherichia
  • Escherichia coli is normal gut flora, but certain serotypes can cause UTIs and diarrhea.

    bacteria infections
  • Pseudomonas aeruginosa is a G- rod that is aerobic and motile.

    bacteria pseudomonas
  • Pseudomonas aeruginosa is known for producing a blue-green pigment called pyocyanin.

    bacteria pigment
  • Pseudomonas aeruginosa is an opportunistic pathogen causing infections in burns, wounds, and the urinary tract.

    bacteria infections
  • Salmonella enterica is a G- rod that is motile with peritrichous flagella.

    bacteria salmonella
  • Salmonella enterica is lactose fermentation-negative and produces H2S.

    bacteria metabolism
  • Salmonella enterica is a common cause of foodborne gastroenteritis from undercooked poultry and eggs.

    bacteria gastroenteritis
  • The Gram stain appearance of Actinomyces israelii is uniform.

    bacteria gram_stain
  • Neisseria meningitidis ferments glucose and maltose.

    bacteria fermentation
  • Pseudomonas aeruginosa is oxidase-positive and is associated with infections in immunocompromised individuals.

    bacteria immunocompromised
  • Escherichia coli can cause traveler's diarrhea and bloody diarrhea in certain serotypes.

    bacteria diarrhea
  • Salmonella enterica forms black colonies on HEK agar due to H2S production.

    bacteria agar
  • Actinomyces israelii is classified as not acid-fast.

    bacteria classification
  • Helicobacter pylori is a G- helical (curved) rod that is microaerophilic and motile with 4-6 flagella.

    bacteria helicobacter microbiology
  • Helicobacter pylori is urease-positive which allows survival in the stomach by producing ammonia to neutralize acid.

    bacteria urease microbiology
  • Helicobacter pylori is found in the stomach and causes chronic gastritis, gastric ulcers, and cancer.

    bacteria diseases microbiology
  • The purpose of the Catalase Test is to detect the enzyme catalase which breaks down hydrogen peroxide (H2O2) into water and oxygen gas.

    tests catalase microbiology
  • In the Catalase Test, the appearance of gas bubbles indicates a positive test.

    tests catalase microbiology
  • The Catalase Test differentiates Staphylococci (catalase-positive) from Streptococci (catalase-negative).

    tests bacteria microbiology
  • The purpose of the Coagulase Test is to detect coagulase, an enzyme that converts fibrinogen to fibrin, causing blood plasma to clot.

    tests coagulase microbiology
  • Bound coagulase causes clumping in a slide test, while free coagulase acts with a plasma factor to form a clot in a tube test.

    tests coagulase microbiology
  • The Coagulase Test distinguishes Staphylococcus aureus (coagulase-positive) from other staphylococci.

    tests bacteria microbiology
  • The purpose of observing Hemolysis on Blood Agar is to observe the effect of hemolysins that lyse red blood cells.

    tests hemolysis microbiology
  • In hemolysis patterns, α-hemolysis indicates partial lysis, creating a dark, greenish zone.

    tests hemolysis microbiology
  • In hemolysis patterns, β-hemolysis indicates complete lysis, creating a clear, yellowish zone.

    tests hemolysis microbiology
  • In hemolysis patterns, γ-hemolysis indicates no lysis or change in the agar.

    tests hemolysis microbiology
  • The purpose of Carbohydrate Fermentation is to determine if a bacterium can ferment a specific sugar, producing acid and/or gas.

    tests fermentation microbiology
  • A color change from red to yellow in the Carbohydrate Fermentation test indicates acid production.

    tests fermentation microbiology
  • The purpose of the Oxidase Test is to detect the presence of cytochrome C oxidase in the electron transport chain.

    tests oxidase microbiology
  • In the Oxidase Test, a redox indicator turns dark-blue when oxidized, signifying a positive test.

    tests oxidase microbiology
  • The Oxidase Test helps differentiate Enterobacteriaceae (most are oxidase-negative) from bacteria like Pseudomonas aeruginosa (oxidase-positive).

    tests oxidase microbiology