Microbiology Chapter 16

What is endotoxin and how does it affect the body?

Endotoxin is released from the LPS (outer membrane) of Gram-negative bacteria, leading to cell death, fever, or shock, and triggers cytokine release.

What is the purpose of the LAL assay?

The LAL assay tests for endotoxins in drugs or medical devices to prevent accidental administration.

What are plasmids?

Plasmids are extrachromosomal, self-replicating DNA in bacteria that can carry genes for antibiotic resistance, toxins, capsules, and fimbriae.

What is lysogenic conversion?

Lysogenic conversion occurs when a lysogenic bacteriophage introduces prophage DNA into a bacterial chromosome, which may carry virulence factors like toxins or capsules.

Give an example of lysogenic conversion.

An example of lysogenic conversion is cholera, where the bacterium acquires a toxin through prophage DNA.

What are cytopathic effects (CPE) in virally infected cells?

Cytopathic effects are visible signs in virally infected cells, including the stopping of mitosis and the release of enzymes that destroy intracellular components.

What are inclusion bodies?

Inclusion bodies are granules containing viral parts, such as Negri bodies associated with rabies.

What is syncytia and which virus is associated with it?

Syncytia is the formation of large cells from neighboring cells merging, commonly seen in respiratory syncytial virus (RSV) infections.

What are the common portals of exit for pathogens?

Common portals of exit include the respiratory tract (sneezing, coughing), gastrointestinal tract (feces), and genitourinary tract (secretion, urine).

How do arthropods and syringes provide exit from the blood

marlaria- mosqitos

What is innate immunity?

nonspecific immunity to carry pathogen

what is susceptibility?

lack of immunity

what is adaptive immunity

specific imunity to a specific pathogen

What are the physical barriers in the first line of defense?

Physical barriers include skin, mucous membranes, tears, saliva, and urine, which help to wash away or trap pathogens.

What role do chemical barriers play in immunity?

Chemical barriers, such as fatty acids in sebum, perspiration, lysozyme, and gastric juices, help to inhibit microbial growth.

What are granulocytes and their types?

Granulocytes are white blood cells with granules; types include neutrophils (fight bacteria), basophils (allergic response), and eosinophils (parasitic infections).

Agranulocytes

momocytes- precursor to macrophages

-lymphocytes

t-lymphocytes (T-cells)

B-lymphocyts (B-cells)

What is phagocytosis?

to swallow and get them out the blood stream

include neutrophils and madcrophages

What is the function of neutrophils?

activated in early stages of infection

wandering macrophages

circulating

fixed macrophages

select tissue

What are the four steps of phagocytosis?

The four steps are chemotaxis (recruitment), adherence (binding to microbes), engulfment (enclosing in a phagosome), and killing (using lysosomal enzymes).

What is the difference between wandering and fixed macrophages?

Wandering macrophages circulate throughout the body, while fixed macrophages are located in specific tissues.

What is the role of T-lymphocytes in adaptive immunity?

T-lymphocytes (T-cells) are crucial for cell-mediated immunity and help in the response against specific pathogens.

What is the role of B-lymphocytes in adaptive immunity?

B-lymphocytes (B-cells) are responsible for producing antibodies against specific antigens.

How do fungi contribute to pathogenicity?

Fungi can form capsules, produce toxins, and trigger allergic responses in the host.

What is the impact of protozoa and helminths on host tissue?

Protozoa and helminths can damage host tissue through parasitic activities and metabolic waste products.

What neurotoxins do algae produce?

Certain algae produce neurotoxins that can affect the nervous system of animals and humans.