Microbiology sectional 2

What is recombinant DNA technology?

A process that involves combining genetic material from different sources to create new DNA molecules for various applications.

Give an example of recombinant DNA technology application.

Producing therapeutic proteins like insulin in bacteria.

What is the basic structure of a virus?

A virus consists of genetic material (DNA or RNA) enclosed in a protein coat called a capsid, and sometimes an outer envelope.

How does a virus differ from a bacterium in terms of reproduction?

Viruses are obligate intracellular parasites and require a host cell to replicate, whereas bacteria reproduce independently through binary fission.

What is normal microbiota?

Microorganisms that reside on or within the human body without causing disease under normal circumstances.

What is a beneficial function of normal microbiota?

They aid in digestion and compete with potential pathogens for resources and space.

What is pathogenicity?

The ability of a microorganism to cause disease.

What is virulence?

The degree or extent of pathogenicity of a microorganism.

How can a microorganism with low pathogenicity still cause disease?

It might cause disease in immunocompromised individuals or if present in very high numbers.

What is innate immunity?

The body's non-specific, first-line defense against pathogens that is present from birth.

What are two examples of physical barriers in innate immunity?

Skin and mucous membranes.

What are examples of chemical barriers in innate immunity?

Stomach acid and lysozyme in tears.

What is the concept of selective toxicity in antimicrobial drugs?

The ability of an antimicrobial drug to kill or inhibit a target microorganism without significantly harming the host's cells.

Why is selective toxicity important for treating infections?

It allows effective treatment of infections with minimal side effects on the patient.

What are the main steps in the lytic cycle of viral multiplication?

Attachment, penetration, replication of genetic material, assembly of new virions, and lysis of the host cell.

What is the difference between a pandemic and an epidemic?

An epidemic is a sudden increase in disease cases in a specific area; a pandemic spreads over several countries or continents.

What are plasmids?

Small, circular DNA molecules separate from a bacterium's main chromosome.

How do plasmids contribute to bacterial pathogenicity?

They can carry genes that encode toxins or antibiotic resistance, facilitating gene transfer between bacteria.

What is phagocytosis?

The process by which certain cells engulf and digest foreign particles, such as bacteria.

What are the primary types of cells involved in phagocytosis?

Neutrophils and macrophages.

What is the role of plasmids in bacteria?

They carry genes that can confer beneficial traits, such as antibiotic resistance.

How do macrophages remove pathogens?

They engulf pathogens and digest them through phagocytosis.

What defines a pathogen?

A microorganism capable of causing disease.

What is an antimicrobial drug?

A chemical substance that kills or inhibits the growth of microorganisms.

What is antimicrobial resistance?

The ability of microorganisms to withstand antimicrobial drugs they were once susceptible to.

What is an epidemic?

A sudden increase in cases of a disease above what is normally expected in a population.

What is a viroid?

An infectious entity composed only of a small, circular single-stranded RNA molecule.

What is a prion?

An infectious agent composed of misfolded protein that can induce abnormal folding in normal proteins.

What is gene therapy?

The introduction of genetic material into cells to treat or prevent disease.

How does inflammation help combat infections?

It causes the area to become reddened, swollen, and hot, bringing immune cells to the site of infection.

What is a major feature of the lysogenic cycle?

The viral DNA integrates into the host cell's chromosome and remains dormant.

What is the significance of epidemiology?

It studies the distribution and determinants of health-related states to control diseases.

How does adaptive immunity differ from innate immunity?

Adaptive immunity is specific and develops over time in response to specific antigens.

What role does stomach acid play in innate immunity?

It serves as a chemical barrier to kill ingested pathogens.

Define virulence factors.

Properties or traits of a pathogen that enhance its ability to cause disease.

What role do neutrophils play in the immune response?

They are the primary cells involved in phagocytosis and inflammation.

How can changes in normal microbiota increase disease susceptibility?

Disruptions can allow pathogenic microorganisms to flourish and cause disease.

What is the significance of selective pressure in antimicrobial resistance?

It leads to the survival of resistant strains of microorganisms.

What is an example of a physical barrier in innate immunity?

The skin.

What is the role of lysozyme in the immune response?

It breaks down the cell walls of bacteria, acting as a chemical barrier.

What happens during the attachment phase of a viral infection?

The virus binds to specific receptors on the surface of the host cell.

What differentiates the lytic cycle from the lysogenic cycle?

The lytic cycle ends in cell lysis, while the lysogenic cycle involves viral DNA integration into the host genome.

Explain the role of macrophages in the immune system.

Macrophages digest foreign particles and contribute to both innate and adaptive immunity.

What is the importance of antibiotic susceptibility testing?

It determines the effectiveness of specific antibiotics against a particular pathogen.

What defines a pathogen's pathogenicity?

Its ability to cause disease.

How do microorganisms attain genetic diversity?

Through processes like mutation, gene transfer, and lateral gene transfer.

What is the effect of mutations on pathogens?

Mutations can lead to changes in virulence or antibiotic resistance.

Why are recombinant DNA technologies important in medicine?

They enable the production of therapeutic proteins and vaccines.

Describe the relationship between microbiota and pathogen competition.

Normal microbiota compete with pathogens for resources, limiting their growth.