Lecture 1 Flashcards
Factors influencing the extent and severity of an infection:
-Host factors:
1- integrity of non-specific defences 2- competence of the immune system 3- genetic capacity of the responds effectively to as specific organism 4- evidence of previous exposure 5- existence of co-infection
Factors influencing the extent and severity of an infection:
Pathogen factors:
Dose
Virulence of organism
Route of entry
Define the infection
When organism enter the body and increase in number and cause the damage to the host
Is a measure of a microbe’s ability to cause disease—————
Virulence
❌✅
Virulence It is a qualitative measure of pathogenicity and
is measured by the number of organisms
required to cause disease
False -Quantitative
The virulence of microbe determined by virulence factor like?
Capsule
Endotoxins
Exotoxins
Normal resistance to infection divided into?
Non-specific resistance
Specific resistance
Non-specific resistance Refers to?
1-Barriers (mechanical,physical,chemical)
2-Phagocytic cell
(*Neutrophil; first cell will be recruited and it is short live but produce in large number/
*Macrophage)
Monocytes/macrophage express receptor for bacterial lipopolysaccharide mention the name of that receptor?
CD14
CD11b/CD18 , CD11c/CD18 Are?
And recognize what?
- Integrin molecules
- leishmania,Bordetella, Candida and LPS
Mention the Receptor that express on Monocytes/Macrophage?
CD14
CD11b/CD18
CD11c/CD18
Mannose receptor
There are two main sites where pathogens may reside in an infected host ?
Extracellularly in tissue spaces
Intracellularly within host cell
The immune system has different mechanisms of dealing with pathogens mention it?
Extracellularly by Antibodies
Intracellulary by cell-mediated immunity
Mention the typical examples of extracellular pathogenic
bacteria ?
Staphylococcus aureus
Streptococcus pyogenes
Pseudomonas aeruginosa
Escherichia coli
Example of extracellular sites?
Mucosal surfaces Vascular Lymphatic Body cavity fluids Interstitial spaces
✅❌
The biochemical, structural, and genetic factors
(virulence factors) play important roles in bacterial
immunity.
False - pathogenesis
Characteristics of bacteria that are pathogens and
can serve as antigens for detection include:
1-Pili and Fimbriae that facilitate attachment to host cells
2- elaboration of proteins that facilitate entry
3- Bacterial toxins(exotoxins and component of cell membrane (endotoxins,LPO)
4- tissue-degrading enzymes and anti-phagocytic factor
Serological Identification of Extracellular Bacteria divided to and the meaning of each one
1- direct serological testing (detecting Antigens)by using specific Antibodies, serogrouping or serotyping
2- indirect serological testing
(Detecting Antibodies ) mainly IgG,IgM
By using synthetized bacteria antigens
Types of Serological Tests.
- Agglutination
- precipitation
- ELISA
- complement Fixation Test
- immunofluoresence
Syphilis disease caused by?and how it is transmitted ?
- Spirochete Treponema Pallidum
- By sexual contact with other person or maternal-fetal or blood
The spirochetes are able to spread into various
organs and cause _______?
Gummas
Mention the stages of Syphilis?
✍️Primary/ inflammatory lesions ‘chancers’ appear 2 to 8 weeks after infection and last 1 to 5 weeks + serum test for syphilis are positive in 90% of patients after 3 weeks + antibody IgM
✍️Secondary/ occurs 6 to 8 weeks after chancre, characterized
by a generalized rash. It is highly contagious. Serologic tests
are positive, antibodies are mostly IgG.
✍️Latent/ serological tests are still positive.
• Early latent • Late latent
✍️Late or tertiary/ May involve any organ, but main parts are:
– Neurosyphilis
– Cardiovascular syphilis
– Late benign (gumma)
✅❌
Congenital syphilis is transmitted to a fetus after 16th
weeks of gestation.
False 18th
✅❌
Infected mother before 18th weeks can transmitted the disease to fetus
False can’t
Infection by the bacteria Treponema pallidum induces production of at least three types of antibodies mention them
Cardiolipin antigen
group-specific antigen
species- specific antigen of T.pallidum
✅❌
The cardiolipin antigen is a hapten
✅
What is the mean by hapten?
elicits the production of an antibody
✅❌
cardiolipin”hapten” Known as reagin antribody
✅
mention tests that are empoly cardiolipin antigen
RPR (rapid plasma reagin
VDRL ( venereal disease research laboratory
✅❌
T. pallidumgroup-specific antigen is polysaccharide in nature.
❌ protein
group-specific antigens found in?
T. pallidumas and Reiter’s treponeme
✅❌
Species-specific treponemalantigen is probably polysaccharide in nature
✅
give an example for specific test in Species-specific antigens of T.pallidum?
T. pallidum hemagglutination TPHA
The treponemesrapidly penetrate the intact mucous
membrane or minor skin abrasions and within a few hours
enter the lymphatics and blood to produce?
systemic
infection
Treponemalantigens induce the production of 2 Antibodies mention them
specific treponemal antibodies
nonspecific reaginic antibodies
Appearance of gummes result from?
delayed hypersensitivity
✅❌
direct detection identify the organism visually using fluorescence microscope
❌ dark field
✅❌
direct detection of syphilis use fluid taken from chancre during primary stage
✅
There are 2 types of serological Tests according to the type Of Ag used?
Non-treponemal Treponemal Antigen tests: Non- Antigen tests: specific(ReaginAb) Specific tests tests using cardiolipin Ag(STANDARD TESTS FOR SYPHILIS)
Treponemal Antigen tests: specific test using pathogenic T. pallidum
explain RPR test
1 -non treponemal test
2- contain charcoal particles for macroscopic reading👁
3-measuring IgM ,IgG
4- more sensitive than VDRL for detection primary stages
explain VDRL?
1- Qualtitative and Quantitave screening procedure
2- the Ag composed of cardiolipin , lecithin, cholesterol
3- in this test the serum in activated at 56c for 30m
4- positive result on spinal fluid diagnostic of neurosyphilis
The Special Diagnosis Area?
congenital syphilis
CNS symptoms
