Presented by:

Group 3 (Fantastic Amoeba)

PHYLUM NEMATODA

Phylum Nematoda (Greek: thread)

Defining Characteristics:

Paired amphids ( anterior chemosensory organs) Vermiform with circular cross

section(roundworms) No Circulatory System Excretory system: renette Linear Digestive System Syncytial Undergo ensheathment Undergo chromosome diminution

Trichuris trichiura Defining Charactristics:

“ Whip worm” Most common gastrointestinal parasites of

human Lack lips Have stichosome esophagus Eggs possess plugs Male have coiled posterior endPathogenesis:

TrichuriasisRectal prolapse IH: none

Trichuris trichiura Taxonomic Key:

Phylum: Nematoda

Class: Aphamida

Order: Trichurida

Family: Trichuridae

Genus:Trichuris

Species: Trichuris

trichiura

Trichuris trichiura Female

MouthStichosome

Trichuris trichiura MaleMouthStichosomeTestesCopulatory spicule

Trichinella spiralis

Defining Characteristics:

“ Trichina Worms” One of the smallest nematode Have calcified cystic wall Pathogenesis:

TrichinosisIH and DH: the sameDiagnosis: Xenodiagnosis

Trichinella spiralis

Taxonomic Key:

Phylum: Nematoda

Class: Aphasmida

Order: Trichurida

Family: Trichinellidae

Genus: Trichinella

Species: Trichinella spiralis

Trichinella spiralis Encysted Larva

Capillaria

Defining Characteristics:

Gradual caudal and cephalic transition Eggs have two plugs with pitsPathogenesis:

CapillariasisIH: fishCapillaria philippinensis

Capillaria

Taxonomic Key:

Phylum: Nematoda

Class: Aphasmida

Order: Trichurida

Family: Capillariidae

Genus: Capillaria

Species: Capillaria

Capillaria

plugs pits

Ascaris lumbricoides

Defining Characteristics:

“Intestinal Roundworm” Chromosome diminution Have three lips Coelomocytes (cells found in pseudocoel)Pathogenesis: Ascariasis Pneumonitis Transplacental migration

Ascaris lumbricoides

Taxonomis Key:

Phylum: Nematoda

Class: Phasmida

Order: Ascaridida

Family: Ascaridoidea

Genus: Ascaris

Species: Ascaris

lumbricoides

Ascaris lumbricoides Female c.s.

CuticleHypodermisMuscular layerOvaries IntestineUterusPseudocoel

Ascaris lumbricoides

Male c.s.

CuticleHypodermisMuscular layerTestesIntestinePseudocoel

Ascaris suum (Pig Ascaris)

Taxonomic Key:

Phylum: Nematoda

Class: Phasmida

Order: Ascaridida

Family: Ascaridoidea

Genus: Ascaris

Species: Ascaris suum

Enterobius vermicularis

Defining Characteritics:

“Pinworms” Cuticle is transparent Have 3 small lips Male is minute Family affairPathogenesis: Itchiness and retrofection

Enterobius vermicularis

Taxonomic Key:

Phylum: Nematoda

Class: Phasmida

Order: Oxyurata

Family: Oxyuroidea

Genus: Enterobius

Species: Enterobius

vermicularis

Wuchereria bancrofti

Defining Characteristics:

Invade lymphatic system and may cause abstruction of lymph passages.

Pathogenesis Elephantiasis or filariasis

IH: Anopheles mosquito

Wuchereria bancrofti

Taxonomic Key:

Phylum: Nematoda

Class: Phasmida

Order: Ascaridida

Family: Filarioidea

Genus: Wuchereria

Species: Wuchereria

bancrofti

Wuchereria bancrofti

Ancylostoma caninum

Defining Characteristics:

“Hookworm” Dentin in buccal capsule Male has copulatory bursaPathogenesis

Creeping eruptionFilariform: infective larvaRhabditiform: juvenile stage

Ancylostoma caninum

Taxonomic Key:

Phylum: Nematoda

Class: Phasmida

Order: Stongylida

Family: Ancylostomatidae

Genus: Ancylostoma

Species:

Ancylostoma caninum

Ancylostoma caninum Rhabditiform

Ancylostoma caninum Filariform

Ancylostoma caninum FemaleDentin/ teethBuccal capsuleOvaries

Ancylostoma caninum Male

Dentin/ teethBuccal capsuleCopulatory bursa

How do you differentiate morphologically the adult forms and eggs of T. trichiura and Capillaria?

What is the characteristic of E. vermicularis eggs making it easily transmissible?

How do you differentiate morphologically the adult forms of Ascaris suum from A. lumbricoides

Differentiate: rhabditiform, filariform and microfilaria

Describe and give the function:a. phasmidsb. amphidsc. renetted. meromyarial musclese. polymyarial muscles

Describe the molting pattern of Nematodes. Which stage is usually infective to the host?

Why do eggs of Ascaris suum do not readily infect humans and vice versa?