- Influenza virus.

- Influenza virus belongs to Orthomyxoviridae family (single-stranded, negative-sense RNA,enveloped viruses and replicate by nuclear replication).

- Genera which are identified by antigenic differences in their nucleoprotein and matrix protein :-

• Influenza A virus.
• Influenza B virus.
• Influenza C virus.

*Influenza Virus Morphology*

- The particles are mostly spherical, 80-120 nm diameter,its core diameter 9 nm and has helical nucleoprotein.

-Nucleoprotein(RNA + nucleoprotein, NP)is any protein which is structurally associated with nucleic acid.

-Matrix proteins(M1,M2)are structural proteins linking the viral envelope with the virus core.

- The virus has a lipid envelope from which project 500 prominent glycoprotein spikes 10 - 14 nm from the surface and are of two types:-

1. Haemagglutinin (HA or H)"the major" which is a sugar-binding protein that mediates binding of the virus to target cells and entry of the viral genome into the target cell.

2. Neuraminidase (NA or N) which is an enzyme involved in the release of virus progeny from infected cells, by cleaving sugars that bind the mature viral particles.

-Ratio of HA to NA is about 4-5 to 1.

(Simplified cartoon showing structure of influenza virus image from Nature)

*Virus Mutation*

-Every 10 - 15 years a major new pandemic strain appears in man, with a totally new H and sometimes a new N as well (Antigenic Shift) which means complete change in HA and NA.

-This new variant may cause a major epidemic around the world.

- Over the subsequent years this strain undergoes minor changes (Antigenic Drift) every two to three years which means incomplete change in HA and NA.

*serotypes:-

- Influenza A viruses are further classified, based on the viral surface proteins (HA or H) and (NA or N) into 16 H subtypes (or serotypes) and 9 N subtypes giving a large number of subtypes due to different associations.

-Influenza B: Known only in man and seals and is less common than influenza A Undergoes relatively slow change in HA with time,consequently is less genetically diverse, with only one influenza B serotype as a result of this lack of antigenic diversity, a degree of immunity to influenza B is usually acquired at an early age.

-Influenza C: Uncommon strain, known only in man and pigs and can cause severe illness and local epidemics.

-Influenza A viruses have an importance nowadays due to lack of specificity to a single host tissue and genome re-assortment which leaded to a panic in the world as for example human Influenza A H1N1 was causing seasonal flu in man and Swine Influenza A H1N1 was causing endemic flu in pigs,swine H1N1 made re-assortment in pig to be transmitted to man leading to pandemic of swine flu in world.

Dr Ibrahim...

- Non typhoidal salmonella.

-Non typhoidal salmonella are bacteria which cause

salmonellosis in human which is a type of

food poisoning...

- While typhoidal salmonella lead to Typhoid

-Non typhoidal salmonella are collected in word

"sect"

- Salmonella Sonnei.

- Salmonella Enteritidis.

- Salmonella Cholerae suis.

- Salmonella Typhimurium.

See you,

Dr Ibrahim.

- DNA fingerprinting.

- The chemical structure of everyone's DNA is the same.

- The only difference between people (or any animal)

is the order of the base pairs.

- There are so many millions of base pairs in each

person's DNA that every person has a different sequence.

-There are high diversity due to presence of non encoding

areas in the strand either in the genetic area

or outside it see here...

- Using these sequences, every person could

be identified by the sequence of their base pairs.

- Each person has a unique DNA fingerprint,

except monozygous (identical) twins.

- DNA fingerprint is the same for every cell,

tissue, and organ of a person. It cannot be

altered by any known treatment. Consequently,

DNA fingerprinting is rapidly becoming the primary

method for identifying and distinguishing among

individual human beings.

- These patterns do not, however, give an

individual "fingerprint," but they are able to

determine whether two DNA samples are from the

same person, related people, or non-related people.

Scientists use a small number of sequences of DNA

that are known to vary among individuals ,

and analyze those to get a certain probability of a matching.

------------------------------------------------

**Practical Applications of DNA Fingerprinting**

1. Paternity and Maternity :

when a father deny that a certain child is belonging

to him Or tow sets of parents claim on one child.

2. Criminal Identification and Forensics:

- In living (strong evidence of involvement

in assault,rape, disputed paternity)

as DNA isolated from blood,hair, skin cells,

or other genetic evidence left at the scene

of a crime can be compared with the

DNA of a criminal suspect .

- In Dead (DNA survives in bone for many years,

comparison of DNA with family members)

3. Personal Identification .

Enjoy it,see you,

Ibrahim

- DNA strucure and terminology.

Chromosomes are thread-like structures located inside the nucleus of cells. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

see the picture which illustrate that also show the true genetic content & non genetic areas....

Promoters: are DNA sequences adjacent to the beginning of the genes and control gene activation.

 

Introns are sequences inside the gene although they do not code for protein sequence they are necessary for correct coding.

 

Exons are the regions inside the gene between introns that contain the coding DNA sequences. 

 

Most of the harmful mutations occur in exons and as a consequence change the structure of the coded protein.

 

- Microbiology practical 2008 full edition.

This is a good power point show of practical Microbiology

from mansoura university 2008

the pictures of high quality  with some questions

and explanations.....

For download from Mediafire clickhere

file size: 51 MB

enjoy it ....

- Keywords of presentation:-

• Seitz Filter.
• Sterile cotton swab.
• Sterile container.
• Autoclave(uses,principle).
• IMMUNO-FLUOReScence slide.
• Anaerobic jar(uses,principle).
• Sterile syringe.
• Microtetration Plate.
• Tissue Culture flask Disposable(small sized).
• Tissue Culture flask Disposable(large sized).
• Tissue Culture flask Disposable With Tissue culture media.
• Tissue culture Plate.
• Tissue culture Bottle.
• Strept. Pyogens in sputum (Gram stain).
• Strept. Pyogens in culture.
• TB Bacilli In sputum (Ziehl neelsen).
• Pneumococci In sputum-Gram stain-
• G ram – ve in culture.
• Diphteroid G +ve bacilli in culture.
• Anthracoid G +ve bacilli in culture.
• Staph In culture G +ve stain.
• Staph In Pus.
• Candida In G stain
• Candida (lacto phenol blue).
• Aspergillus (lacto phenol blue).
• Staph, G- Ve in culture(Gram stain).
• Candida , G- Ve in culture (Gram stain).
• Candida , Anthracoid.
• Candida , Staph.
• Macconkey Agar plate.
• Non Lactose frementer On macconkys agar.
• Dorset Egg medium.
• Lofflers serum.
• Endopig .Staph on N. Agar .
• Exopig. Of pseudomonas aeruginosa.
• Nutrient Deep Agar.
• Nutrient Agar slope.
• Nutrient Agar plate.
• Aspergillus Niger on saberaud s dextrose agar.
• Litmus milk.
• Cooked meat medium.
• Lowenstein Jensen medium.
• Non lactose frementer on CLED agar.
• lactose fermenter on CLED agar.
• Blood Agar plate (uninoculated).
• Chocolate agar plate.
• Alpha hemolysis on blood agar.
• B hemolysis on blood agar.
• Antibiotic sensitivity Test.
• Widal test.
• Wassermann test.
• Biochemical reaction for salmonella.
• Biochemical reaction for shigella.
• Biochemical reaction of IMVC.

- Cells Of Immune response

Cells Of Immune response are classified Into five classes according to
A- Presence of specific structures on their surface.
B- Their Functions.
 
The cells Of Immune response are:-

1- B lymphocytes.
2- T lymphocytes.
3- Accessory cells :

• Macrophages
• Dendritic cells
• Polymorphnuclear cells

4- Killer cells :

• Natural killer cells ( Nk cells )
• Killer cells ( K cells )

5- Mast cells

Dr Ibrahim