Shorts

Function of Adhesins

Attachment: Microbial adhesins bind specifically to host cell receptor molecules.

Colonization: This tight binding prevents the bacteria from being washed away by body fluids.

Infection start: Firm attachment is a critical first step that lets germs colonize and start an infection.

1. Coagulase:

• Definition: Coagulase is an enzyme produced by certain bacteria, most notably Staphylococcus aureus. It catalyzes the conversion of fibrinogen (a soluble plasma protein) into fibrin (an insoluble protein), leading to the clotting of blood.
• Function: The production of coagulase is a virulence factor for Staphylococcus aureus, as it helps the bacteria evade the host's immune system by forming a protective clot around the bacterial cells. This clot can shield the bacteria from phagocytosis and other immune responses.
• Clinical Relevance: Coagulase is used in laboratory tests to differentiate between pathogenic Staphylococcus aureus (coagulase-positive) and non-pathogenic staphylococci (coagulase-negative).

2. Proteolytic Enzymes:

• Definition: Proteolytic enzymes, also known as proteases or peptidases, are enzymes that catalyze the breakdown of proteins into smaller peptides or amino acids by cleaving the peptide bonds between amino acids.
• Function: These enzymes play crucial roles in various biological processes, including digestion, protein turnover, cell signaling, and immune responses. They are found in many organisms, including humans, where they are involved in the digestion of dietary proteins in the stomach and small intestine.
• Types: Proteolytic enzymes can be classified based on their mechanism of action (e.g., serine proteases, cysteine proteases, aspartic proteases, and metalloproteases) and their substrate specificity.

Wenmycin is an antibiotic that is derived from the bacterium Streptomyces wenyangensis. It belongs to the class of compounds known as macrolide antibiotics, which are characterized by their large lactone ring structure. Wenmycin has been studied for its antimicrobial properties, particularly against certain types of bacteria.

Bordetella pertussis, a bacterium that infects the airways and causes severe, uncontrollable coughing fits.

Name: Bordetella pertussis

Type: Gram-negative bacterium

Target: The respiratory tract and cilia of the host

Symptoms: Severe coughing spells followed by a high-pitched "whoop" sound

Correct answer: 2) To ensure efficient and synchronous annealing during the reaction

Resistance Mechanisms

Receptor mutation: Altering outer membrane proteins or lipopolysaccharides so the phage cannot bind.

CRISPR-Cas systems: Destroying incoming phage DNA using specialized RNA-guided nucleases.

Restriction-modification: Cutting foreign phage DNA with restriction enzymes while protecting host DNA.

Abortive infection: Triggering cell death or dormancy to stop the spreading of the virus to nearby cells.