1. Microbiology lab review
Made by: Khaled

2. Specimens Stool Blood Serum and plasma
Others (anal swab, duodenal aspirate, sputum, urine, urogenital specimen)
Tissues and aspirates

3. What kinds of tests are used to diagnose parasitic diseases?
A fecal (stool) exam
Also called an ova and parasite test (O&P).
This test is used to find parasites that cause diarrhea, loose or watery stools, cramping, flatulence (gas) and other abdominal illness.
CDC recommends that three or more stool samples, collected on separate days, be examined.
This test looks for ova (eggs) or the parasite.

4. 2. Endoscopy/Colonoscopy
Endoscopy is used to find parasites that cause diarrhea, loose or watery stools, cramping, flatulence (gas) and other abdominal illness.
This test is used when stool exams do not reveal the cause of your diarrhea.
This test is a procedure in which a tube is inserted into the mouth (endoscopy) or rectum (colonoscopy) so that the doctor, usually a gastroenterologist, can examine the intestine.
This test looks for the parasite or other abnormalities that may be causing your signs and symptoms.

5. 3. Blood tests :Some, but not all, parasitic infections can be detected by testing your blood. Blood tests look for a specific parasite infection.
There are two general kinds of blood tests:
Serology :This test is used to look for antibodies or for parasite antigens produced when the body is infected with a parasite and the immune system is trying to fight off the invader.
Blood smear :This test is used to look for parasites that are found in the blood. By looking at a blood smear under a microscope, parasitic diseases such as filariasis, malaria, or babesiosis, can be diagnosed.
This test is done by placing a drop of blood on a microscope slide. The slide is then stained and examined under a microscope

6. Cyst of E. histolytica stained with trichrome
Cyst of E. histolytica stained with trichrome. Note the chromatoid body with blunt ends (red arrow)
Trophozoites of E. histolytica with ingested erythrocytes stained with trichrome.

7. T. cruzi trypomastigote in a thin blood smear stained with Giemsa.
Leishmania sp. amastigotes in a Giemsa-stained tissue scraping

8. Toxoplasma gondii – tachzoite. Arrow points to a tachzoite of T
Toxoplasma gondii – tachzoite. Arrow points to a tachzoite of T.gondii in cardiac muscle.
Plasmodium falciparum- gametocyte. Arrow points to a ‘’banana-shaped’’ gametocyte of Plasmodium falciparum.

9. Fertilized egg
Adult female A. lumbricoides
Unfertilized egg of A. lumbricoides

10. Microfilaria of W. bancrofti in a thick blood smear stained with Giemsa
Egg of S. mansoni in unstained wet mounts.
Proglottid of T. saginata injected with India Ink

11. Fungi

12. Dermatophtosis (ringworm)

13. Tinea versicolor

14. Sporotrichosis

15. Mycetoma

16. Histoplasma capsulatum Yeasts within macrophages
Histoplasma capsulatum Yeasts within macrophages. Arrow points to a macrophage continaning several purple stained yeastes in the cytoplasm.

17. Candida albicans – yeast. Long arrow points to a budding yeast
Candida albicans – yeast. Long arrow points to a budding yeast. Short arrow points to the outer membrane of a vaginal epithelial cell.
Candia albicans- pseudohyphae. Two arrows point to pseudohyphae of candida albicans.

18. Aspergillus
Disease: Aspergillus species, especially Aspergillus fumigatus, cause infections of the skin, eyes, ears and other organs. “fungus ball” in the lungs. And allergic bronchopulmonary aspergillosis.
Form in tissue seen by microscopy: Mold with septate hyphae.
Important Clinical Findings : Fungus ball in lung, wound and burn infection, indwelling catheter infections, sinusitis.
Laboratory Diagnosis: Culture grows mold with green spores, candidia in radiating chains.

19. Viruses

20. These are electron micrographs of a virus
َ Q2: Describe its structure. This is an electron micrograph of a virus Q: Name this virus, Answer: Herpes virus.
Herpes virus
Q1: Name this virus
Enveloped virus ,
Icosahedral capsid,
d.s DNA genome
Q2: Describe its structure.

21. This is an electron micrograph of a virus
َ Q2: Describe its structure. This is an electron micrograph of a virus Q: Name this virus, Answer: Herpes virus.
Adenovirus
Q1: Name this virus
Nonenveloped virus,
Icosahedral capsid & d.s DNA genome
Q2: Describe its structure.

22. This is an electron micrograph of a virus
َ Q2: Describe its structure. This is an electron micrograph of a virus Q: Name this virus, Answer: Herpes virus.
Rabies virus
Q1: Name this virus
Enveloped virus , Helical capsid
& s.s RNA genome
Q2: Describe its structure.

23. This is an electron micrograph of a virus
Q1: Name this virus
Influenza Viruses
Enveloped Virus with spikes ,
Helical capsid ,Segmented s.s RNA
Q2: Describe its structure

24. Block 4

25. Hemolysis 1. Alpha (α) hemolytic streptococci:
Alpha (α) hemolytic streptococci produce a greenish discolouration with partial hemolysis around the colonies.
The zone of lysis is small (1 or 2 mm wide) .
These are known as ‘viridans streptococci’ or Streptococcus viridians (from ‘viridis’ meaning green).
The alpha streptococci are normal commensals in the throat, but may cause opportunist infections rarely.

26. 2. Beta (β) hemolytic
streptococci Beta (β) hemolytic streptococci produce a sharply defined, clear, colourless zone of hemolysis, 2-4mm wide, within which red cells are completely lysed.
The term ‘hemolytic streptococci’ strictly applied only to beta lytic strains.
Most pathogenic streptococci belong to this group.
3. Gamma (γ) or nonhemolytic streptococci
Gamma (γ) or nonhemolytic streptococci produce no change in the medium and so are sometimes referred to as ‘indifferent streptococci’.

27. Alpha-hemolysis on blood agar (Streptococcus pneumoniae)
Beta-hemolysis on blood agar (Streptococcus pyogenes)
Gamma-hemolysis on blood agar (Escherichia coli)

28. Optochin test
Optochin (or ethylhydrocupreine) is a chemical used in cell culture techniques for the presumptive identification of Streptococcus pneumoniae, which is optochin-sensitive, from other alpha-hemolytic streptococci such as Streptococcus viridans, which are resistant.
The growth of bacteria that are optochin-sensitive will be inhibited around an optochin disc, while the growth of bacteria that are optochin-resistant will not be affected.

30. Bacitracin Test
Bacitracin is a bactericidal drug useful in the treatment of superficial skin infections but too toxic for systemic use.
Bacitracin is a polypeptide antibiotic produced by Bacillus subtilis. This drug interferes in the peptidoglycan synthesis of Bacteria. 
The presumptive identification of group A streptococci (GAS) is usually done by testing for sensitivity to bacitracin.
 Bacitracin test is used to determine the effect of a small amount of bacitracin on an organism.

32. Bile solubility test
The bile (sodium deoxycholate) solubility test distinguishes S. pneumoniae from all other alphahemolytic streptococci. S. pneumoniae is bile soluble whereas all other alpha-hemolytic streptococci are bile resistant.
Sodium deoxycholate (2% in water) will lyse the pneumococcal cell wall.
Reading the bile solubility test results
A clearing of the turbidity in the bile tube but not in the saline control tube indicates a positive test.