Term
| Define Toxigenesis and Toxin |
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Definition
Different to infection(due to cell growth),disease cause specific pathogen's toxin.
Products of a pathogen that destroys host's tissue allowing it to spread. |
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Term
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Definition
| A type of symbiosis where pathogens adversely affects the host. |
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Term
| Entry via Urogenital tract are |
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Definition
Nissera Gonorrhea
All other STDs |
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Term
| Examples of pathogens that can enter the host via the respiratory tract are? |
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Definition
Legionella pneumophilia
Mycobactreum tuberculosis
Both can survrive in the lungs. |
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Term
| Fimbrae is an example of a bacterial Adhesin.What is it exactly and what are the types? |
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Definition
filamentous appendages the extend out of the cell surface of bacterial.
Examples
Type 1 fimbriae in enterobacteria
Type 1 fimbrae |
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Term
| Give an example of how Phenotype types of cell surface receptors depend on genotype of the host. |
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Definition
| Certain groups within a host population may be immune to certain pathogense e.g;some pple r not infected with HIV bcoz they do not express HIV receptor CCR-5 on their cell. |
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Term
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Definition
| abaility of pathogen to spread to other tissues in the body. |
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Term
| Pathoges that use Gastrontestinal tract entry include? |
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Definition
Helicobacter pylori(Stomach ,causes ulcers)
Vibrio cholera(Small intestine,cholera)
Shigella
Salmonella
Can bypass the mucous membrane layer and bind with the epithelial. |
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Term
| T/F fever is a defence mechanism and y? |
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Definition
True.Because;
it stimulates phagocytic cells
triggers the host to decrease the amt of availbale iron.
Enhances B and T cell response. |
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Term
| T/FVirulence genes in bacteria may be encoded on chromosomal DNA,bacterophage DNA,plasmids and transposons |
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Definition
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Term
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Definition
| ability of pathogen to secrete toxins |
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Term
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Definition
| Degree or intensity of pathogenesity |
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Term
| WHat are other types of bacterial adhesin molecules? |
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Definition
Capsules
LPS
Techoic acid
Protein F(Streptococcus pyogenes)
Fibronectin (stapylococcus aureus) |
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Term
| What are invasion factors? |
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Definition
| Factors that enable bacteria to invade host cells and facilitate entry of mucosal surfaces.They are usually extracellular substances. |
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Term
| What are some of the examples of pathogens that can break with Skin to enter the host? |
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Definition
Rabies
Yersinia Pestis(Plague)
Stretptococci
Hepatitis B virus
Pseudomonas(Affects burns)
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Term
| What are the two components of Specific defence system? |
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Definition
Humoral Immune system (Antibody Mediated)
Cell-mediated immune response. |
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Term
| What are the two types of Host's Defence? |
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Definition
| Non specific and Specific host defences. |
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Term
| What are the types of bacterial invasins? |
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Definition
- Hyaluronidase-produced by Gram+ and attack the connective tissue b2n cells which break apart the tissues.
- Collagenase-produced by Clostridium and breaks down collagen.
- Neuramidase-Produces by Gram- and break down intracellular cement(Neuramic acid) of the epithelial cells.
- Coagulase-Produced by staphylococcus and converts fibrinogen to fibrin which cause clotting of the blood.
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Term
| What can receptors be made of? |
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Definition
| Specific carb or peptide residues of the host cell surface. |
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Term
| What consists of non specific defence system? |
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Definition
Exogenous pyrogens-produced by Invading pathogens
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Term
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Definition
They do not kill the host cell.
act on the cell where bacteria is actively growing
damege host cell and enable immediate spread of the pathogens. |
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Term
| What does a pathogen need to cause disease? |
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Definition
- Come into contact and enter the host.
- Attach to the specific host tissues and colonise it.
- Invade the host tissues and cause infection
- Produce toxins and other factors to allow it to produce disease.
- Grow and survive within the host.
- Evade the host immune system.
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Term
| What does adherence to host tissue require? |
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Definition
| Receptor of the host and the adhesin of the pathogen. |
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Term
| What does adhesins being specific mean? |
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Definition
That bacteria will only;
Infect certain tissue types
infect certain hosts
infect certain subspecies of the host. |
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Term
| What is a bacteria adhesin? |
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Definition
| A protein or glycoprotein found on the cell surface which interacts with the host cell receptor. |
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Term
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Definition
| a process in which there is an intense contest b2n pathogens and host's immune defenses. |
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Term
| What makes a host susceptible? |
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Definition
Nutrition status
Age
Hyperferremia(Too much iron)
Abnomalities of the immune system.
Prior infections
Genetic disorders. |
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Term
| What makes up the exogenous pyrogens? |
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Definition
| LPS,parts od the peptigoglycan layer,soluble enterotoxins,other proteins or carb molecules. |
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Term
| What r the 3 types of toxins? |
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Definition
Endotoxin-components of the LPS especially the Lipid A.
Exotoxins-proteins secreted from the bacterial cell into the extracellular envt.R soluble protein thus they can be carries to all parts of the body.
They are often cytotoxic(Cna kill cells)E.g
Diphtheria toxin.
Botulism toxin
tetanus toxin
Hemolysins-are enzymes that act on anilmal's cell membranes.they lyse the red blood cells.e.g Staphylococci and Ecoli. |
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Term
| What r the factors that are involved in disease? |
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Definition
Virulence of the pathogen
Number of pathogens
Heath&age ot the host. |
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Term
| Y can pathogens only infect certains cells? |
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Definition
| bcoz different cells have have different cell receptors.E.g only humans can be infected by haemophillus influenzae. |
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Term
| how do pathogens transmit disease? |
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Definition
Direct contact(Sneezing,caughing)
Pathogens are airborne
Some pathogens are on various surfaces
Pathogens are within soil
Some pathogens can be transmitte via vectors(e.g Insects) |
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Term
| what does ID50 stand for and what is its significance? |
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Definition
| IInfectious Dose 50.The lower the ID50 the more virulent/pathogenic the pathogen. |
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Term
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Definition
| Pathogen's abolity to cause disease. |
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