Microbiology: Flagella and Motility

Questions and Answers

What is one function of flagella in bacteria?

DNA replication

Going toward specific nutrients (correct)

Protein synthesis

Energy production

How can flagella contribute to bacterial pathogenicity?

By helping bacteria escape their normal niche (correct)

By increasing nutrient absorption

By enhancing cell division

By facilitating DNA transfer

In what way are flagella categorized concerning virulence?

They are metabolic enzymes

They are antigenic (antigen H) (correct)

They serve as storage structures

They are crucial cell wall components

What role do flagella play in the context of a bacterium's environment?

Escape dangerous structures Signup and view all the answers

Which statement about flagella is incorrect?

They are only found in pathogenic bacteria Signup and view all the answers

What can super-antigens lead to as a significant health issue?

Shock and organ failure Signup and view all the answers

What is the primary function of the mediator protein in relation to endotoxins?

To help attach endotoxins to immune cells Signup and view all the answers

Which type of toxin is identified as Toxic Shock Syndrome Toxin (TSST)?

Super-antigen Signup and view all the answers

Which immune cells are primarily targeted by endotoxins when binding occurs?

Monocytes and macrophages Signup and view all the answers

What role does interleukin-1 (IL1) play in the immune response to endotoxins?

It induces cytokine production Signup and view all the answers

What type of bacteria do first generation cephalosporins primarily target?

Gram + cocci Signup and view all the answers

Which of the following is NOT effectively targeted by first generation cephalosporins?

Enterococcus Signup and view all the answers

What is a characteristic of a composite transposon?

It includes genes for antimicrobial resistance. Signup and view all the answers

What is the activity level of first generation cephalosporins against gram - bacteria?

Moderate activity Signup and view all the answers

Which of the following features differentiates a composite transposon from a simple transposon?

Presence of extra genes coding for antimicrobial resistance. Signup and view all the answers

Which statement about first generation cephalosporins is correct?

They target MRSA effectively. Signup and view all the answers

What additional element is found in a composite transposon compared to a simple transposon?

Antimicrobial resistance genes. Signup and view all the answers

Among the following, which type of bacteria are first generation cephalosporins least effective against?

Gram - bacilli Signup and view all the answers

What term describes the extra genes found in composite transposons?

Antimicrobial resistance genes. Signup and view all the answers

Which statement is true regarding the structure of a composite transposon?

It shares the same structure as a simple transposon. Signup and view all the answers

Which types of bacteria does streptomycin primarily target?

Enterococci and tuberculosis Signup and view all the answers

What is the mechanism of action of streptomycin?

Binds to the 30S subunit and causes mRNA misreading Signup and view all the answers

Which of the following statements about streptomycin is incorrect?

It is effective against Gram-positive bacteria only. Signup and view all the answers

Which ribosomal subunit does streptomycin target to inhibit protein synthesis?

30S subunit Signup and view all the answers

What effect does streptomycin have on mRNA during protein synthesis?

It causes misreading of the mRNA. Signup and view all the answers

Study Notes

Flagella

Enable bacteria to swim toward nutrients and escape harmful environments.
Serve as an important virulence factor, allowing certain motile normal flora to transition into pathogenic forms.
Possess antigenic properties, identified as antigen H.
Composite transposons include extra genes for antimicrobial resistance along with those coding for transposon properties and their flanking sequences.
Super-antigens, like TSS toxin, can provoke severe immune responses, resulting in shock, organ failure, and circulatory collapse.

Endotoxins: LPS

LPS does not directly bind to cell receptors; instead, it requires a mediator protein for attachment to immune cells (monocytes and macrophages).
Mediated interactions induce the release of cytokines and interleukin-1 (IL-1).

First Generation Cephalosporin

Exhibits high activity against gram-positive cocci, effective against MRSA but not enterococci.
Displays moderate activity against gram-negative bacteria.

Streptomycin

Does not require a specific structure for its function.
Targets bacteria such as enterococci and Mycobacterium tuberculosis.
Works by binding to the 30S ribosomal subunit, disrupting initiation of protein synthesis and causing misreading of mRNA.

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Description

This quiz explores the role of flagella in bacteria, focusing on their function in nutrient acquisition and evading harmful environments. It covers the significance of motility in pathogenicity and the antigenic properties of flagella. Test your understanding of how flagella contribute to bacterial survival and virulence.