GIARDIA LAMBLIATRICHOMONAS VAGINALIS

PLASMODIUM SP. (P. VIVAX, P. FALCIPARUM)

Laboratory class #2

PHYLUM: METAMONADA (OLD NAME FLAGELLATES)- GIARDIA LAMBLIA DISEASE: GIARDIASIS

▪Giardia lamblia (or G. duodenalis, or G. intestinalis)

▪Microscopic parasite (protozoan)

▪Giardia infection is an intestinal infection marked by stomach cramps, abdominal pain, bloating, nausea and bouts of watery diarrhea

▪Giardia usually spreads when G. lamblia cysts within feces contaminate food or water, which is later consumed orally. The disease can also spread between people and through other animals. Factors that increase possible contamination include travelling in the developing world, changing diapers, consuming raw food, and owning a dog. Cysts may survive for nearly three months in cold water.

▪Giardia is diagnosed via stool tests

THE LIFE CYCLE IS COMPOSED OF 2 STAGES:

1. Trophozoite which exists freely in the human small intestine

2. The cyst which is passed into the environment

• No intermediate hosts are required

GIARDIA LAMBLIA

G. duodenalis trophozoites are pear-shaped cells, 10 to 20 micrometers long, 7 to 10 micrometers across, and 2 to 4 micrometers thick. They are motile by way of four pairs of flagella, which propel the trophozoites through the intestine. Notably, each G. duodenalis cell has two nuclei, both of which actively transcribe genes. Each cell also contains a pair of rigid structures called median bodies which make up part of the G. lamblia cytoskeleton. Trophozoites adhere to host epithelial cells via a specialized disk-shaped organelle called the ventral disk.

Cysts are oval-shaped cells slightly smaller than trophozoites. They lack flagella, and are covered by a smooth, clear cyst wall. Each cyst contains the organelles for two trophzoites: four nuclei, two ventral disks, etc.

LIFE CYCLE OF GIARDIA LAMBLIA

Task #1. To study and sketch a Trophozoite

and a cyst of Giardia lamblia

PHYLUM: METAMONADA (OLD NAME FLAGELLATES) -TRICHOMONAS VAGINALIS

Trichomoniasis (trich) is an infectious disease caused by the parasitic protozoan Trichomonas vaginalis. Trichomoniasis is a sexually transmitted infection

Symptoms: itching in the genital area, a bad smelling thin vaginal discharge, burning with urination, and pain with sex

Diagnosis is by finding the parasite in the vaginal fluid using a microscope, culturing the vagina or urine, or testing for the parasite's DNA

The human genital tract is the only reservoir for this species. Only trophozoite stage, no cysts.

The single-celled protozoan produces mechanical stress on host cells and then ingests cell fragments after cell death

DISEASE: TRICHOMONIASIS

TRICHOMONAS VAGINALIS

Unlike other parasitic protozoa (Giardia lamblia, Entamoeba histolytica etc.), Trichomonas vaginalis exists in only one morphological stage, a trophozoite, and cannot encyst. The T. vaginalis trophozoite is oval as well as flagellated, or "pear" shaped as seen on a wet-mount. It is slightly larger than a white blood cell, measuring 9 × 7 μm. Five flagella arise near the cytostome; four of these immediately extend outside the cell together. Another distinguishing feature of Trichomonas is the presence of an undulating membrane. The undulating membrane is a fin-like extension of the plasma membrane located on the side of the organism. A flagellum that extends to the posterior end of the organism is attached to the outer edge of the undulating membrane.

In addition, a conspicuous barb-like axostyle projects opposite the four-flagella bundle. The axostyle may be used for attachment to surfaces and may also cause the tissue damage seen in trichomoniasis infections. The nucleus is usually elongated, and the cytoplasm contains many hydrogenosomes.

LIFE CYCLE OFTRICHOMONAS VAGINALIS

TRICHOMONAS VAGINALIS

Task #2. To study and sketch a trophozoite of Trichomonas vaginalis

PHYLUM: APICOMPLEXA DISEASE: MALARIA- PLASMODIUM SP. (P. VIVAX, P. FALCIPARUM)

▪Protozoal parasite and a human pathogen

▪Infects red blood cells in mammals (including humans), birds, and reptiles, occurs worldwide, especially in tropical and temperate zones

▪The organism is transmitted by the bite of the female Anopheles mosquito

▪Plasmodium species exhibit three life-cycle stages - gametocytes, sporozoites, and merozoites

PLASMODIUM VIVAXLIFE CYCLE [1]

Plasmodium parasites are spread by the bite of infected female Anophelesmosquitoes, which feed on human blood in order to nourish their own eggs. While taking its meal (usually between dusk and dawn), an infected mosquito injects immature forms of the parasite, called sporozoites, into the person’s bloodstream. The sporozoites are carried by the blood to the liver, where they mature into forms known as schizonts. Over the next one to two weeks each schizont multiplies into thousands of other forms known as merozoites.

PLASMODIUM VIVAXLIFE CYCLE [2]

The merozoites break out of the liver and reenter the bloodstream, where they invade red blood cells, grow and divide further, and destroy the blood cells in the process. The interval between invasion of a blood cell and rupture of that cell by the next generation of merozoites is about 48 hours for P. falciparum, P. vivax, and P. ovale. In P. malariae the cycle is 72 hours long. Most merozoites reproduce asexually - that is, by making identical copies of themselves rather than by mixing the genetic material of their parents.

PLASMODIUM VIVAXLIFE CYCLE [3]

A few, however, develop into a sexual stage known as a gametocyte. These will mate only when they enter the gut of another mosquito that bites the infected person. Mating between gametocytes produces embryonic forms called ookinetes; these embed themselves in the mosquito’s gut, where they mature after 9 to 14 days into oocysts, which in turn break open and release thousands of sporozoites that migrate to the insect’s salivary glands, ready to infect the next person in the cycle.

Ring stage

Schizont

Task #3. To study

and sketch three

stages of

Plasmodium vivax’

life cycle: ring stage,

sporozoite and

schizont

Sporozoite