Microbiology: Bacterial Cell Wall Components

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What is the role of Lipoteichoic Acid in the attachment process?

Cleaves hyaluronic acid

Blocks the actions of antibodies

Attaches to blood clots and traumatized tissues (correct)

Binds to prothrombins

Which enzyme is responsible for converting fibrinogen to fibrin in the context provided?

Proteases

Lipase

Coagulase (correct)

Hyaluronidase

How do Exoenzymes Lipase and FAME negatively affect the immune system?

By digesting hyaluronic acid

By inhibiting the actions of antibodies

By acting on fatty acids and lipids as surfactants (correct)

By enhancing invasiveness

What is the primary function of Proteases in the context provided?

Block the actions of antibodies Signup and view all the answers

Which factor can V8 protease degrade, leading to bacterial spread after adhesion?

Fibrinogen-binding protein Signup and view all the answers

How do Enterotoxins contribute to illness when ingested?

Lead to diarrhea and vomiting Signup and view all the answers

What is the mechanism by which enterotoxins can cause Toxic Shock Syndrome (TSS)?

By acting as superantigens and stimulating T cells Signup and view all the answers

Which toxin is responsible for causing a spectrum of diseases from bullous impetigo to the scalded skin syndrome in humans?

Exfoliative Toxin (ETA, ETB) Signup and view all the answers

Which toxin is known for causing mastitis in ruminants via infection through the teat?

Beta (β) Toxin Signup and view all the answers

What is the primary function of Delta (δ) Toxin?

Unknown use, being a very small peptide Signup and view all the answers

Which toxin triggers septic shock by inflammatory mediator release?

Alpha (α) Toxin Signup and view all the answers

What is the key characteristic of Exfoliative toxin of S.aureus regarding its effect on different species?

Affects humans and mice but not pigs Signup and view all the answers

Which Lancefield Group is associated with neonatal sepsis and meningitis?

Group B (S.agalactiae) Signup and view all the answers

What is the predominant hemolysis pattern observed in Gamma (γ) hemolysis?

No hemolysis Signup and view all the answers

How is the C-substance antigen extracted in the conventional method for Lancefield Groupings?

Autoclaving Signup and view all the answers

Which agent causes Scarlet fever and toxic-shock-like syndrome in humans?

Group A (S.pyogenes) Signup and view all the answers

What media is commonly used for the isolation of Lancefield Groups?

Blood agar Signup and view all the answers

What type of test is conducted using kits commercially available to identify different Lancefield Groups?

Latex Agglutination Test Signup and view all the answers

What is the motility of Listeria spp.?

Motile by peritrichous flagella Signup and view all the answers

Which agar does Listeria spp. not grow on?

MacConkey agar Signup and view all the answers

What is the hemolytic status of Listeria grayi?

Non-hemolytic Signup and view all the answers

Which species of Listeria is considered non-pathogenic?

L. innocua Signup and view all the answers

What is the natural habitat of Listeria spp.?

Soil and decaying vegetation Signup and view all the answers

What food types are associated with listeriosis in humans?

Soft cheeses and poultry meat Signup and view all the answers

What is a distinguishing characteristic of C.bovis?

Small, white, dry, non-hemolytic Signup and view all the answers

How do the colonies of C.kutscheri typically appear?

Small, whitish, resembling C.pseudotuberculosis Signup and view all the answers

What is a common characteristic of C.pseudotuberculosis colonies after prolonged incubation?

Small, dry, cream in color with a narrow zone of hemolysis Signup and view all the answers

How do the colonies of C.renale evolve over time?

Non-hemolytic and very small initially, becoming opaque and dull yellow as they age Signup and view all the answers

What is a distinguishing characteristic of C.pilosum compared to C.renale?

Dry and cream to yellow in color with time Signup and view all the answers