Trematodes Developmental Stages PDF

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Warning: TT: undefined function: 32TrematodesGio Treb V. Rivera1. Paragonimus westermaniA. What are the developmental stages of trematodes? Eggs become embryonated Miracidia hatch and seek the first intermediate host (snail) Sporocyst ➔ rediae ➔ cercariae (developmental stage of miracidia) Cercariae...

Description

Trematodes Gio Treb V. Rivera

1. Paragonimus westermani A. What are the developmental stages of trematodes? Eggs become embryonated Miracidia hatch and seek the first intermediate host (snail) Sporocyst ➔ rediae ➔ cercariae (developmental stage of miracidia) Cercariae invades second intermediate host (fresh water crabs) Encysts into metacercariae and matures to adult worms in pairs in diaphagm or lung. B. Submit pictures of trematodes (ova, larvae, adult). 1. 2. 3. 4. 5.

OVA

Miracidium

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Eggs are operculated with wide operculum, contains undeveloped miracidum Eggs are with abopercular thickening Eggs are similar to those produced by Diphyllobothrium latum

The typical oval, red- to brown-colored adult P. westermani measures 1 by 0.7 cm. The cuticle possesses spines, similar to the other adult trematodes. Bean-shaped equipped with oral and ventral suckers. They have two large branching testes in the posterior half of the body and an ovary.

2. Fasciolopsis buski A. What are the developmental stages of trematodes? 1. 2. 3. 4. 5. 6.

Eggs become embryonated in water Eggs release miracidia which invades a suitable snail intermediate host Sporocyst ➔ rediae ➔ cercariae (developmental stage of the snail parasite) Cercariae are then released from snail Encysts as metacercariae Then developed into adult worm on the intestinal wall if ingested from aquatic plants by mammalian host.

B. Submit pictures of trematodes (ova, larvae, adult). OVA

LARVAE

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

The typical F. buski egg measures 128 to 140 µm by 78 to 85 µm.

The adult F. buski measures approximately 5 by 1.5 cm.

They consist of an oblong undeveloped miracidium equipped with a distinct operculum.

Without cephalic cone & intestinal ceca is unbranched. Have poorly-developed oral and ventral suckers.

3. Fasciola hepatica A. What are the developmental stages of trematodes? 1. Eggs become embryonated in freshwater over ~2 weeks. 2. embryonated eggs release miracidia, which invade a suitable snail intermediate host 3. In the snail, the parasites undergo several developmental stages (sporocysts ➔ rediae ➔ cercariae). 4. The cercariae are released from the snail and encyst as metacercariae on aquatic vegetation or other substrates. 5. Humans and other mammals become infected by ingesting metacercariae-contaminated vegetation. 6. Metacercariae excyst in the duodenum and matures into adult worm and produce eggs through the liver parenchyma into biliary ducts.

B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Miracidium

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult.

OVA

F. hepatica egg measures 128 to 150 µm by 60 to 90 µm. They consist of an oblong undeveloped miracidium equipped with a distinct operculum.

ADULT

The adult F. hepatica measures approximately 3 by 1 cm. F. hepatica is equipped with so-called shoulders. With cephalic cone & branched intestinal ceca. 2 suckers: oral and ventral.

4. Fasciola gigantica A. What are the developmental stages of trematodes? 1. Eggs become embryonated in freshwater over ~2 weeks. 2. embryonated eggs release miracidia, which invade a suitable snail intermediate host 3. In the snail, the parasites undergo several developmental stages (sporocysts ➔ rediae ➔ cercariae). 4. The cercariae are released from the snail and encyst as metacercariae on aquatic vegetation or other substrates. 5. Humans and other mammals become infected by ingesting metacercariae-contaminated vegetation. 6. Metacercariae excyst in the duodenum and matures into adult worm and produce eggs through the liver parenchyma into biliary ducts. B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Miracidium

LARVAE

ADULT

Cercaria

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Larger than F. hepatica egg They consist of an oblong undeveloped miracidium equipped with a distinct operculum.

The adult F. gigantica measures approximately 75 mm by 15 mm Leaf shape with less prominent shoulders and with parallel margins 2 suckers: oral and ventral.

5. Echinostoma ilocanum A. What are the developmental stages of trematodes? 1. Eggs are passed in feces of infected definitive hosts and develop in water. 2. Miracidia usually hatched after 3 weeks of maturation, in which they swim freely and penetrate the first intermediate host, a snail 3. Then develops into: sporocyst stage ➔ one or two generations of rediae ➔ cercariae a. ****The cercariae may encyst as metacercariae within the same first intermediate host or leave the host and penetrate a new second intermediate host*** 4. The definitive host becomes infected after eating metacercariae in infected second intermediate hosts 5. Metacercariae excyst in the duodenum and matures into adult worm in small intestine. B. Submit pictures of trematodes (ova, larvae, adult). OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Eggs are operculated, contains undeveloped miracidium.

Oral sucker is equipped with CIRCUM ORAL DISK with spine

Straw-colored

Reddish gray

Similar to Fasciola and Fasciolopsis buski ova

49-51 collar spines Integument is covered by plaque like scales Simple intestinal caeca

6. Heterophyes heterophyes A. What are the developmental stages of trematodes? 1. Adults release embryonated eggs each with a fully-developed miracidium, and eggs are passed in the host’s feces 2. After ingestion by a suitable snail (Genera Cerithidia and Pironella), the eggs hatch and release miracidia which penetrate the snail’s intestine. 3. Miracidium undergo developmental stages (sporocysts ➔ rediae ➔ cercariae) 4. The cercariae are released from the snail and encyst as metacercariae. 5. Cercariae encysts as metacercariae in tissues of suitable brackish fish. 6. If ingested, the metacercariae excyst, attach to the mucosa of the small intestine and mature into adult worms. B. Submit pictures of trematodes (ova, larvae, adult). OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Their eggs are operculated, with narrow operculum, contains developed miracidium NO abopercular knob opposite the operculum H. heterophyes eggs are thick shelled

The adult Heterophyes worm is small, measuring just over 1.0 by 0.5 mm in size. The pyriform organism is grayish in color and is protected by an outer layer of fine spines that are scaly in appearance. The tests are large and paired, and are situated near a small ovary With central THIRD SUCKER/GENITAL SUCKER

7. Metagonimus yokogawai A. What are the developmental stages of trematodes? 1. Adults release fully embryonated eggs each with a fully-developed miracidium, and eggs are passed in the host’s feces 2. After ingestion by a suitable snail (genus Semisulcospira), the eggs hatch and release miracidia which penetrate the snail’s intestine 3. Miracida undergoes developmental stage (sporocysts ➔ rediae ➔ cercariae) 4. The cercariae are released from the snail 5. Cercarciae encyst as metacercariae in the tissues of a suitable fresh/brackish water fish. 6. If ingested, the metacercariae excyst, attach to the mucosa of the small intestine and mature into adult worms. B. Submit pictures of trematodes (ova, larvae, adult). OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Their eggs are operculated, with narrow operculum, contains developed miracidium. NO abopercular knob opposite the operculum Thin shelled

The adult Metagonimus measurres approximately 1.5 by 0.5 mm. The worm is also pyriform in shape, with tapering at the anterior end and rounding at the posterior end. A tiny layer of scaly spines covers the organism, which is heavily distributed over the anterior end. Metagonimus yokogawai – without central third sucker

8. Clonorchis sinensis A. What are the developmental stages of trematodes?

1. 2. 3. 4. 5. 6.

Eggs are ingested by intermediate host (snail) Eggs release miracidia Miracidia undergoes several developmental stage (sporocysts➔ rediae ➔cercariae) Cercariae are released from snail Cercariae encyst as metacercariae in flesh of the freshwater fish. After ingestion by humans, the metacercariae excyst in the duodenum and matures to adult worms in biliary ducts.

B. Submit pictures of trematodes (ova, larvae, adult).

OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

ADULT

Their eggs are operculated, with wide operculum, contains developed miracidium Opposite the operculum is the abopercular knob Broadly ovoidal Resemble an old fashioned electric bulb

with granular vitellaria & dendritic testes The average adult C. sinensis measures 2 by 0.5 cm. Each end of the adult worm is narrower than the midportion of the body

9. Fasciola lanceolata or Dicrocoelium dendriticum A. What are the developmental stages of trematodes?

1. Embryonated eggs containing miracidia are shed in feces 2. When the miracidia hatch in the first intermediate host (snail) 3. Miracidia migrates to gut wall and settle into the adjacent vascular connective tissue (following development of: Miracidia ➔ Sporocyst ➔ daughter Sporocyst ➔cercaria) 4. Cercariae shed in slime ball from snail and ingested by 2nd intermediate host (ant) and become metacercariae. 5. When the infected ant is eaten by suitable definitive host, metacercariae excyst in the small intestine and mature into adult worms in bile duct. B. Submit pictures of trematodes (ova, larvae, adult).

OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult.

OVA

ADULT

Eggs are operculated and measure 3545 µm long by 20-30 µm wide. The eggs are thick-shelled and usually dark brown in color. Eggs are fully embryonated when shed in feces.

Adults of are flattened and taper at both the anterior and posterior ends. The paired testes lie just behind the anteriorly-located ventral sucker (acetabulum). The ovary is small and located behind the testes.

10. Opistorchis felineus & Opistorchis viverrini A. What are the developmental stages of trematodes? 1. The eggs passed from feces release miracidia 2. Miracidia, ingested by snail undergo several developmental stages (sporocysts ➔ rediae ➔ cercariae) 3. Cercariae are released from the snail and penetrate freshwater fish (second intermediate host), encysting as metacercariae in the muscles or under the scales. 4. If ingested by definitive host, metacercariae excyst in the duodenum and mature into adult worms in the ampulla of vater into the biliary ducts. B. Submit pictures of trematodes (ova, larvae, adult). LARVAE

O. felineus

OVA

Cercaria

ADULT

LARVAE

OVA

ADULT

O. viverrini

`

Cercaria

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

Their eggs are operculated, with wide operculum, contains developed miracidium Oopposite the operculum is the abopercular knob Elongately ovoid

ADULT

Adults measure approximately 7 mm long by 1.5 mm wide in the human host (adults are slightly smaller in feline hosts) Transverse vitellaria & lobed testes

11. Schistosoma japonicum A. What are the developmental stages of trematodes? 1. Eggs are eliminated in feces 2. The contained embryo develops into MIRACIDIUM 3. Ciliated MIRACIDIUM hatches from the egg in water 4. Miracidium penetrates Oncomelania hupensis quadrasi 5. SPOROCYST develops from miracidium. 6. From Sporocyst, CERCARIA develops 7. Cercaria escape from snail, penetrates unbroken skin of man 8. Enters circulatory system, pass through heart and lungs 9. Enters liver develops into adult worms and mate 10. Migration to mesenteric venules of bowel/rectum and lay eggs

B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Miracidium

LARVAE

ADULT

Cercaria

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

Non-operculated, pale yellow With MINUTE LATERAL KNOB/SPINE Tissue or cells maybe adherent. Size is 55-65 x 70-100 um

ADULT Adult Skin

smooth

Number of testes in adult male

6 – 7 (males have gynecophoral canal)

Egg output of adult female

50 – 100

Uterus in adult female

Long and well developed

Location of ovary in adult female

Median/ Central

12. Schistosoma haematobium A. What are the developmental stages of trematodes? 1. Eggs are eliminated in urine 2. The contained embryo develops into MIRACIDIUM 3. Ciliated MIRACIDIUM hatches from the egg in water 4. Miracidium penetrates Bulinus, Physopsis spp. 5. SPOROCYST develops from miracidium. 6. From Sporocyst, CERCARIA develops 7. Cercaria escape from snail, penetrates unbroken skin of man 8. Enters circulatory system, pass through heart and lungs 9. Enters liver develops into adult worms and mate 10. Migration to venous plexus of bladder and lay eggs. B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Cercaria

Miracidium

LARVAE

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

Non-operculated with TERMINAL SPINE Measures 55-65 x 110-170 um

ADULT Adult Skin

With fine tuberculations

Number of testes in adult male

8 – 9 (males have gynecophoral canal)

Egg output of adult female

1–4

Uterus in adult female

long

Location of ovary in adult female

13. Schistosoma mansoni A. What are the developmental stages of trematodes? 1. Eggs are eliminated in feces 2. The contained embryo develops into MIRACIDIUM 3. Ciliated MIRACIDIUM hatches from the egg in water 4. Miracidium penetrates Biomphalaria, Planorbis, or Tropicorbis spp. 5. SPOROCYST develops from miracidium. 6. From Sporocyst, CERCARIA develops 7. Cercaria escape from snail, penetrates unbroken skin of man 8. Enters circulatory system, pass through heart and lungs 9. Enters liver develops into adult worms and mate 10. Migration to mesenteric venules of bowel/rectum and lay eggs.

B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Posterior

Miracidium

LARVAE

ADULT

Cercaria

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

Non-operculated egg with LATERAL SPINE. Measures 45-70 x 115 –175 um

ADULT Adult Skin

With coarse tuberculations

Number of testes in adult male

4 – 5 (males have gynecophoral canal)

Egg output of adult female

20 – 30

Uterus in adult female

short

Location of ovary in adult female

Anterior half

14. Schistosoma mekongi A. What are the developmental stages of trematodes? (species similar to S. japonicum) 1. 2. 3. 4.

Eggs are eliminated in feces The contained embryo develops into MIRACIDIUM Ciliated MIRACIDIUM hatches from the egg in water Miracidium penetrates Oncomelania hupensis quadrasi (restricted to the Mekong River area of southeast Asia) 5. SPOROCYST develops from miracidium. 6. From Sporocyst, CERCARIA develops 7. Cercaria escape from snail, penetrates unbroken skin of man 8. Enters circulatory system, pass through heart and lungs 9. Enters liver develops into adult worms and mate 10. Migration to mesenteric venules of bowel/rectum and lay eggs

B. Submit pictures of trematodes (ova, larvae, adult). OVA

LARVAE

Cercaria

ADULT

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

Non-operculated, pale yellow With MINUTE LATERAL KNOB/ SMALL INCONSPICUOUS SPINE Tissue or cells maybe adherent. The eggs are similar to S. japonicum, but are generally smaller (50-80 µm by 40-65 µm).

ADULT

Adult worms are dioecious, where males and females are morphologically different. Male worms can grow up to 2.2 cm, while females grow up to 2.6 cm (7). Adults have both an oral and ventral sucker which attaches to the venous wall, preventing blood flow from dislodging the parasite. The worms are an off-white color, and the male possesses a gynecophoric channel; a trough running laterally in which the female rests. This is known as eternal copulation, and is most commonly found in the mesenteric venous plexus.

15. Schistosoma intercalatum A. What are the developmental stages of trematodes? (related to S. haematobium) 1. 2. 3. 4. 5. 6. 7. 8. 9.

Eggs are eliminated in stool The contained embryo develops into MIRACIDIUM Ciliated MIRACIDIUM hatches from the egg in water Miracidium penetrates Bulinus, Physopsis spp. (but restricted to east-central Africa) SPOROCYST develops from miracidium. From Sporocyst, CERCARIA develops Cercaria escape from snail, penetrates unbroken skin of man Enters circulatory system, pass through heart and lungs Enters liver develops into adult worms and mate 10. Migration to mesenteric venules of bowel/rectum and lay eggs.

B. Submit pictures of trematodes (ova, larvae, adult).

OVA

Cercaria

LARVAE

Zaire strain dorsal teguments

ADULT

Ventral teguments

Gabon strain dorsal teguments

Ventral teguments

Cameroon strain dorsal teguments

Ventral teguments

-https://www.parasitejournal.org/articles/parasite/pdf/1987/03/parasite1987623p235.pdf

C. Identify the distinguishing characteristics of each trematodes as to its ova and adult. OVA

The eggs are similar to S. haematobium in general shape Possessing a terminal spine, but are usually longer (140-240 µm) Often have an equatorial (central) bulge and are shed in stool, not urine.

ADULT

The two strains Zaire and Gabon are very similar. Small tubers (6-10 µm long axis) alternate with larger tubers (13-14 µm). They are all spindle shaped. They are covered with short spines, with mossy tips, not very tight, the apex of many tubers remaining glabrous, however. The dorsal integuments differ little from the ventral integuments

The thorns located between the tubers are abundant, particularly on the ventral integuments. They are sli...