Aim
To observe the disease-causing organisms like Ascaris, Entamoeba, Plasmodium and Ringworm through permanent slides.
Materials Required
Preserved slides or specimens of disease-causing organisms like Ascaris, Entamoeba, Plasmodium and Ringworm.
Procedure
Observe the specimens or slides and identify the organism on the basis of its features.
Observations
Ascaris
Phylum: Aschelminthes
Class: Nematoda
Type: Ascaris lumbricoides
Ascaris exhibits the following characteristic features:
• It has a long, cylindrical and unsegmented body.
• The male and female organisms are separate.
• It bears a mouth at the anterior end surrounded by three lips.
• There is an excretory pore on the ventral surface slightly behind the anterior end.
• A pair of penial spicules are present in the male worms close to the cloacal opening.
• The female genitals are present at about one-third distance from the anterior end.
Ascariasis is the disease caused by Ascaris lumbricoides or roundworm.
Symptoms:
• Abdominal cramping
• Abdominal swelling
• Nausea
• Vomiting
• Fever
Entamoeba
Phylum: Protozoa
Class: Rhizopoda
Type: Entamoeba hystolytica
Following are the characteristic features of Entamoeba:
• It is a unicellular organism with an irregular shape.
• It consists of a few food vacuoles. The contractile vacuole is absent.
• Cysts with four nuclei are present.
• It consists of a nucleus located eccentrically in the cell.
Entamoeba histolytica is an organism found in the intestines of humans that is responsible for causing amoebic dysentery.
Symptoms:
• Abdominal pain
• Watery diarrhoea with mucus, blood and pus
• Fatigue
• Fever
• Nausea
• Vomiting
Plasmodium
Phylum: Protozoa
Class: Sporozoa
Type: Plasmodium vivax
Plasmodium can be identified by the following characteristic features:
• It is a unicellular endoparasite found within the red blood cells of the diseased person.
• The parasite is mostly diagnosed at the “signet ring” stage where the parasite appears as a round body.
• There is a big vacuole present inside the cell. The cytoplasm is accumulated at one place and contains the nucleus.
Plasmodium vivax is a protozoan parasite that causes malaria in humans. The infected female anopheles bites a healthy person and transmits the sporozoite into the peripheral blood vessels of humans, thereby, causing malaria.
Symptoms:
• High fever
• Shaking chills from moderate to severe.
• Headache
• Vomiting
• Nausea
Ringworm
Kingdom: Fungi
Class: Deuteromycetes
Type: Trichophyton rubrum
Trichophyton or ringworm fungus has the following characteristic features:
• This fungus feeds on the keratin of the skin of human beings.
• The hyphae are waxy and can be smooth or cotton-like.
• Hyphae that are not stained are yellowish-brown, reddish-brown or white in colour.
Ringworm is a communicable fungal infection of the skin.
Symptoms:
• Scaly, itchy skin
• Red and raised patches
• They are redder at the periphery than at the centre and forms a ring-like appearance.
