This document provides information about flagellates that can cause intestinal infections in humans. It describes the key characteristics and life cycles of two important intestinal flagellates: Giardia intestinalis and Dientamoeba fragilis. Giardia intestinalis exists as pear-shaped trophozoites that attach to the small intestine and cysts that are transmitted between hosts. Dientamoeba fragilis exists only as trophozoites in the large intestine without invading tissues. Both can cause intermittent diarrhea but often result in asymptomatic infections. Diagnosis involves microscopic examination of stool samples to identify the organisms. Treatment involves antibiotics like metronidazole or paromomycin.
This document summarizes information about various intestinal flagellates and ciliates that can infect humans. It discusses the taxonomy, morphology, life cycles, transmission routes, pathogenesis and treatment of several important species, including Giardia lamblia, Chilomastix mesnili, Trichomonas species, Balantidium coli, and Ichthyopthirius multifiliis. Key points covered include the stages, structures and habitats of these parasites as well as how they are transmitted and can cause disease in humans or other hosts.
Cryptosporidium parvum is a protozoan parasite that causes cryptosporidiosis. It infects the intestinal epithelial cells and is transmitted through the fecal-oral route, often through contaminated water. The parasite undergoes both asexual and sexual reproduction in the small intestine, forming oocysts that are shed in feces and are immediately infectious. Infection causes watery diarrhea that can last for weeks and lead to dehydration, especially in young children and immunocompromised individuals. Diagnosis is through microscopic identification of oocysts in stool samples and treatment options are limited. Prevention involves proper hygiene, water treatment, and food safety practices.
This document discusses Balantidium coli, a ciliated protozoan parasite that causes the disease balantidiasis in humans. It has two life stages, a motile trophozoite stage that inhabits the large intestine and reproduces, and an infective cyst stage that is transmitted through fecal contamination. Symptoms include diarrhea, dysentery, abdominal pain and ulceration of the intestinal wall. Diagnosis is made by examining stool samples under a microscope. Treatment involves oral antibiotics such as tetracycline or metronidazole.
Fasciola hepatica, commonly known as the sheep liver fluke, is a parasitic flatworm that infects the livers of sheep and cattle. It can also infect humans. The adult fluke lives in the bile ducts of the liver and lays eggs that pass in the feces. The life cycle requires an intermediate snail host to continue development. People become infected by ingesting metacercariae encysted on aquatic plants like watercress. Clinical symptoms in humans range from fever and abdominal pain during migration to liver damage and obstruction of the bile ducts in chronic infections. Diagnosis is confirmed by finding characteristic eggs in stool or biopsy samples. Treatment involves medications like triclabendazole.
- Clostridium tetani is the causative organism of tetanus. It is a gram-positive, spore-forming bacillus found in soil and the intestines of humans and animals.
- The organism produces a powerful neurotoxin called tetanospasmin which causes the symptoms of tetanus by blocking inhibitory neurotransmission in the spinal cord, resulting in muscular rigidity and spasms.
- Tetanus is diagnosed clinically and confirmed by culturing C. tetani from a wound. Treatment involves controlling spasms, maintaining airway, administering human tetanus immunoglobulin and antibiotics while actively immunizing to prevent future illness.
Rickettsia are tiny, obligate intracellular bacteria that can cause diseases like Rocky Mountain spotted fever when transmitted to humans via arthropod vectors like ticks and mites. They grow within the cells of vertebrates and can be cultured in embryonated eggs or tissue cell culture. Rickettsia have cell walls, undergo binary fission, and are sensitive to antibiotics unlike viruses. Chlamydia are also obligate intracellular bacteria with two forms - the infectious elementary body and reproductive reticulate body. They have a characteristic developmental cycle but are unable to produce their own ATP. Mycoplasmas are the smallest bacteria that can be grown on artificial media and lack cell walls, taking on various shapes. Their colonies in
- Ancylostoma duodenale, commonly known as the old world hookworm, infects humans in tropical and subtropical regions. It lives in the small intestine and feeds on host blood, causing iron-deficiency anemia.
- The adult worm lays eggs that pass in feces and hatch as larvae in soil. These larvae penetrate the skin, migrate through lungs, are swallowed and mature in the small intestine.
- Infection causes ground itch, creeping eruption, and iron-deficiency anemia marked by pallor and weakness. Diagnosis involves finding eggs in feces or larvae in sputum. Treatment includes albendazole and iron supplements.
This document summarizes information about various intestinal flagellates and ciliates that can infect humans. It discusses the taxonomy, morphology, life cycles, transmission routes, pathogenesis and treatment of several important species, including Giardia lamblia, Chilomastix mesnili, Trichomonas species, Balantidium coli, and Ichthyopthirius multifiliis. Key points covered include the stages, structures and habitats of these parasites as well as how they are transmitted and can cause disease in humans or other hosts.
Cryptosporidium parvum is a protozoan parasite that causes cryptosporidiosis. It infects the intestinal epithelial cells and is transmitted through the fecal-oral route, often through contaminated water. The parasite undergoes both asexual and sexual reproduction in the small intestine, forming oocysts that are shed in feces and are immediately infectious. Infection causes watery diarrhea that can last for weeks and lead to dehydration, especially in young children and immunocompromised individuals. Diagnosis is through microscopic identification of oocysts in stool samples and treatment options are limited. Prevention involves proper hygiene, water treatment, and food safety practices.
This document discusses Balantidium coli, a ciliated protozoan parasite that causes the disease balantidiasis in humans. It has two life stages, a motile trophozoite stage that inhabits the large intestine and reproduces, and an infective cyst stage that is transmitted through fecal contamination. Symptoms include diarrhea, dysentery, abdominal pain and ulceration of the intestinal wall. Diagnosis is made by examining stool samples under a microscope. Treatment involves oral antibiotics such as tetracycline or metronidazole.
Fasciola hepatica, commonly known as the sheep liver fluke, is a parasitic flatworm that infects the livers of sheep and cattle. It can also infect humans. The adult fluke lives in the bile ducts of the liver and lays eggs that pass in the feces. The life cycle requires an intermediate snail host to continue development. People become infected by ingesting metacercariae encysted on aquatic plants like watercress. Clinical symptoms in humans range from fever and abdominal pain during migration to liver damage and obstruction of the bile ducts in chronic infections. Diagnosis is confirmed by finding characteristic eggs in stool or biopsy samples. Treatment involves medications like triclabendazole.
- Clostridium tetani is the causative organism of tetanus. It is a gram-positive, spore-forming bacillus found in soil and the intestines of humans and animals.
- The organism produces a powerful neurotoxin called tetanospasmin which causes the symptoms of tetanus by blocking inhibitory neurotransmission in the spinal cord, resulting in muscular rigidity and spasms.
- Tetanus is diagnosed clinically and confirmed by culturing C. tetani from a wound. Treatment involves controlling spasms, maintaining airway, administering human tetanus immunoglobulin and antibiotics while actively immunizing to prevent future illness.
Rickettsia are tiny, obligate intracellular bacteria that can cause diseases like Rocky Mountain spotted fever when transmitted to humans via arthropod vectors like ticks and mites. They grow within the cells of vertebrates and can be cultured in embryonated eggs or tissue cell culture. Rickettsia have cell walls, undergo binary fission, and are sensitive to antibiotics unlike viruses. Chlamydia are also obligate intracellular bacteria with two forms - the infectious elementary body and reproductive reticulate body. They have a characteristic developmental cycle but are unable to produce their own ATP. Mycoplasmas are the smallest bacteria that can be grown on artificial media and lack cell walls, taking on various shapes. Their colonies in
- Ancylostoma duodenale, commonly known as the old world hookworm, infects humans in tropical and subtropical regions. It lives in the small intestine and feeds on host blood, causing iron-deficiency anemia.
- The adult worm lays eggs that pass in feces and hatch as larvae in soil. These larvae penetrate the skin, migrate through lungs, are swallowed and mature in the small intestine.
- Infection causes ground itch, creeping eruption, and iron-deficiency anemia marked by pallor and weakness. Diagnosis involves finding eggs in feces or larvae in sputum. Treatment includes albendazole and iron supplements.
- Escherichia coli (E. coli) is a common bacteria that normally lives in the intestines of humans and animals. However, some strains of E. coli can cause illness, including diarrhea.
- E. coli that causes diarrhea is divided into six groups that produce diarrhea through different pathogenic mechanisms, such as the production of heat-stable or heat-labile toxins. One group, enterotoxigenic E. coli (ETEC), commonly causes travelers' diarrhea.
- In addition to diarrhea, E. coli can cause other illnesses like urinary tract infections, wound or blood infections, and even sepsis. The type of specimen collected for testing depends on the suspected infection.
LUMEN DWELLING FLAGELLATES - GIARDIA
REFS:
INTERNATIONALLY ACCEPTED BOOK OF MEDICAL PARASITOLOGY BY K. D. CHATTERJEE
TEXT BOOK OF MEDICAL PARASITOLOGY BY PANIKER
IMAGE SOURCES : FROM INTERNET
This document provides information on nematodes (roundworms). It discusses key characteristics of nematodes such as their elongated shape and presence of a cuticle. It also describes the classification and life cycles of several medically important nematodes that infect humans, including Ascaris lumbricoides (roundworm), Ancylostoma duodenale (hookworm), Strongyloides stercoralis, Trichinella spiralis (trichina worm), Enterobius vermicularis (pinworm), and Trichuris trichiura (whipworm). For each nematode, it covers features such as the adult worm morphology, eggs, life cycle, pathogenicity, clinical signs, and methods for laboratory
Contributions of Edward jenner, Robert koch and Joseph ListerShruthi Krishnaswamy
The document provides biographical information on four important scientists in microbiology - Joseph Lister, Robert Koch, Edward Jenner, and Louis Pasteur. It describes their backgrounds and key contributions, such as Lister's pioneering work in antiseptic surgery, Koch's studies identifying the specific bacteria that cause anthrax, tuberculosis, and cholera and developing techniques to grow pure cultures, Jenner developing the world's first vaccine for smallpox using cowpox, and Pasteur's discoveries debunking spontaneous generation and demonstrating that microorganisms cause fermentation and disease.
PowerPoint about laboratory diagnosis of Taenia species (T.saginata and T. solium ) .Contain information about diagnosis with picture to simplify understanding .
The document discusses hemoflagellates, single-celled flagellated parasites that infect the blood and tissues of humans and animals. It describes the structure, life cycles, transmission, geographic distribution, pathogenesis, diagnosis, treatment, and prevention of two important genera of hemoflagellates: Trypanosoma brucei, which causes African sleeping sickness, and Trypanosoma cruzi, which causes Chagas disease in South and Central America. Key aspects of the parasites, diseases they cause, and approaches to control are summarized.
Clostridium tetani, botulinum, and difficile, by Dr. Himanshu KhatriDrHimanshuKhatri
- Clostridium tetani causes tetanus and enters the body through cuts or wounds in the skin. It produces a neurotoxin that causes painful muscle spasms. C. botulinum causes botulism by ingesting its toxin in contaminated food which causes paralysis. C. difficile causes diarrhea and colitis when normal gut flora is disrupted by antibiotics allowing it to overgrow and produce toxins.
This document summarizes key information about Taenia species, including T. saginata, T. solium, T. asiatica, and T. multiceps. It describes the medically important species, diseases they cause, hosts, morphology, life cycles, transmission, diagnosis and treatment. T. saginata and T. solium cause taeniasis in humans. T. solium can also cause cysticercosis, which can lead to seizures. T. saginata uses cattle as an intermediate host while T. solium uses pigs. Diagnosis involves examining stool for eggs or proglottids. Cysticercosis is diagnosed via imaging, biopsy or serology. Treatment
Helminthology is such an important topic not only in India but worldwide. Here is an introduction to the medically important parasites causing diseases to man.
Helminths are elongated parasitic worms that can infect humans. They are classified into two phyla - Platyhelminths (flatworms like tapeworms and flukes) and Nemathelminths (roundworms). Helminths have complex life cycles involving larval and adult stages and often require more than one host. They can infect various parts of the body including the intestines, liver, lungs, blood and tissues. Common helminth infections in humans include tapeworms, flukes, roundworms and filarial worms.
Parasitology is the study of parasites, which can live internally or externally on a host. This document discusses different types of parasites including parasitic protists like Plasmodium spp. (which causes malaria), helminths like the roundworm Ascaris, and fungi. It defines terms like definitive host, intermediate host, and reservoir host. It also describes the life cycles and transmission of various parasites and the diseases they can cause.
Cryptosporidium parvum is an enteric parasite that is one of the most common causes of diarrhea worldwide. It is transmitted through the fecal-oral route, often through contact with contaminated water. The oocyst stage of its life cycle is very resilient and can survive in water even after treatment. Infection occurs when an oocyst embeds itself in the gut epithelium. There is no cure for immunocompromised individuals who become infected.
The document discusses various sporozoan parasites including Sarcocystis, Cryptosporidium, Toxoplasma, Eimeria, Isospora, and Plasmodium species. It provides details on the parasite biology, life cycles, pathogenesis, clinical manifestations, diagnosis, treatment and prevention of diseases caused by these sporozoans. Key points covered include that sporozoans are obligate parasites with complex life cycles involving sexual and asexual reproduction, and they cause diseases by infecting tissues through ingestion of infective stages such as oocysts or sporocysts.
Trematodes are flatworm parasites that are dorsoventrally flattened and unsegmented. They have two suckers and incomplete digestive tracts. Blood flukes include schistosomes which have complex multi-host life cycles involving snail and human hosts. The three main types that infect humans are Schistosoma japonicum, S. mansoni, and S. haematobium. Lung flukes include Paragonimus westermani which uses crabs as an intermediate host. Intestinal flukes include Fasciolopsis buski, a large fluke found in the intestines, and Echinostoma ilocanum, known as Garrison's fluke, which
This presentation was given at the Delmarva Small Ruminant Conference All Worms All Day on December 8, 2018, in Keedysville, Maryland. The presenter was Susan Schoenian.
This document discusses the Taenia solium parasite, also known as the pork tapeworm. It has an adult stage that lives in the human intestine and a larval stage (cysticercus cellulose) that lives in pigs. The life cycle involves humans ingesting pork contaminated with the larval cysts, which develop into the adult tapeworm in the small intestine. Common symptoms in humans include abdominal pain, diarrhea and nausea. The larval cysts can also spread to other tissues like brain, eyes and muscles, causing neurocysticercosis with symptoms depending on the location of cysts. Diagnosis involves examination of stool samples or imaging tests, while treatment involves antiparasitic medications like albendazole
1. Entamoeba histolytica is one of the most important pathogenic protozoa that infects humans. It causes amebiasis through the transmission of infective cysts from feces to mouth via contaminated food or water.
2. The life cycle involves cyst ingestion, excystation in the small intestine, colonization of the large intestine by trophozoites, and formation of cysts that are passed in feces. Trophozoites can invade the intestinal lining and spread to other organs.
3. Symptoms range from mild abdominal discomfort to severe dysentery. Most infections are asymptomatic but some can cause life-threatening extra-intestinal complications like liver abscesses if left untreated
They have distinct cell nuclei and membrane-bound organelles which allow for compartmentalization and dedication of specific areas of the cell for specific functions.
Plays a very important role in the phylogeny of all eukaryotes.
They serve as the stem group for the fungi, plants, and animals.
Major groups within this kingdom include the algae, euglenoids, ciliates, protozoans and flagellates.
This document provides information about protozoa. It discusses that protozoa are eukaryotic, unicellular organisms that are either autotrophic or heterotrophic. They can reproduce asexually through binary fission or multiple fission, or sexually. The document categorizes protozoa into four major groups: flagellated protozoa, amoeboid protozoa, coccidea, and ciliates. It provides examples and details about different phyla and classes within these groups.
- Escherichia coli (E. coli) is a common bacteria that normally lives in the intestines of humans and animals. However, some strains of E. coli can cause illness, including diarrhea.
- E. coli that causes diarrhea is divided into six groups that produce diarrhea through different pathogenic mechanisms, such as the production of heat-stable or heat-labile toxins. One group, enterotoxigenic E. coli (ETEC), commonly causes travelers' diarrhea.
- In addition to diarrhea, E. coli can cause other illnesses like urinary tract infections, wound or blood infections, and even sepsis. The type of specimen collected for testing depends on the suspected infection.
LUMEN DWELLING FLAGELLATES - GIARDIA
REFS:
INTERNATIONALLY ACCEPTED BOOK OF MEDICAL PARASITOLOGY BY K. D. CHATTERJEE
TEXT BOOK OF MEDICAL PARASITOLOGY BY PANIKER
IMAGE SOURCES : FROM INTERNET
This document provides information on nematodes (roundworms). It discusses key characteristics of nematodes such as their elongated shape and presence of a cuticle. It also describes the classification and life cycles of several medically important nematodes that infect humans, including Ascaris lumbricoides (roundworm), Ancylostoma duodenale (hookworm), Strongyloides stercoralis, Trichinella spiralis (trichina worm), Enterobius vermicularis (pinworm), and Trichuris trichiura (whipworm). For each nematode, it covers features such as the adult worm morphology, eggs, life cycle, pathogenicity, clinical signs, and methods for laboratory
Contributions of Edward jenner, Robert koch and Joseph ListerShruthi Krishnaswamy
The document provides biographical information on four important scientists in microbiology - Joseph Lister, Robert Koch, Edward Jenner, and Louis Pasteur. It describes their backgrounds and key contributions, such as Lister's pioneering work in antiseptic surgery, Koch's studies identifying the specific bacteria that cause anthrax, tuberculosis, and cholera and developing techniques to grow pure cultures, Jenner developing the world's first vaccine for smallpox using cowpox, and Pasteur's discoveries debunking spontaneous generation and demonstrating that microorganisms cause fermentation and disease.
PowerPoint about laboratory diagnosis of Taenia species (T.saginata and T. solium ) .Contain information about diagnosis with picture to simplify understanding .
The document discusses hemoflagellates, single-celled flagellated parasites that infect the blood and tissues of humans and animals. It describes the structure, life cycles, transmission, geographic distribution, pathogenesis, diagnosis, treatment, and prevention of two important genera of hemoflagellates: Trypanosoma brucei, which causes African sleeping sickness, and Trypanosoma cruzi, which causes Chagas disease in South and Central America. Key aspects of the parasites, diseases they cause, and approaches to control are summarized.
Clostridium tetani, botulinum, and difficile, by Dr. Himanshu KhatriDrHimanshuKhatri
- Clostridium tetani causes tetanus and enters the body through cuts or wounds in the skin. It produces a neurotoxin that causes painful muscle spasms. C. botulinum causes botulism by ingesting its toxin in contaminated food which causes paralysis. C. difficile causes diarrhea and colitis when normal gut flora is disrupted by antibiotics allowing it to overgrow and produce toxins.
This document summarizes key information about Taenia species, including T. saginata, T. solium, T. asiatica, and T. multiceps. It describes the medically important species, diseases they cause, hosts, morphology, life cycles, transmission, diagnosis and treatment. T. saginata and T. solium cause taeniasis in humans. T. solium can also cause cysticercosis, which can lead to seizures. T. saginata uses cattle as an intermediate host while T. solium uses pigs. Diagnosis involves examining stool for eggs or proglottids. Cysticercosis is diagnosed via imaging, biopsy or serology. Treatment
Helminthology is such an important topic not only in India but worldwide. Here is an introduction to the medically important parasites causing diseases to man.
Helminths are elongated parasitic worms that can infect humans. They are classified into two phyla - Platyhelminths (flatworms like tapeworms and flukes) and Nemathelminths (roundworms). Helminths have complex life cycles involving larval and adult stages and often require more than one host. They can infect various parts of the body including the intestines, liver, lungs, blood and tissues. Common helminth infections in humans include tapeworms, flukes, roundworms and filarial worms.
Parasitology is the study of parasites, which can live internally or externally on a host. This document discusses different types of parasites including parasitic protists like Plasmodium spp. (which causes malaria), helminths like the roundworm Ascaris, and fungi. It defines terms like definitive host, intermediate host, and reservoir host. It also describes the life cycles and transmission of various parasites and the diseases they can cause.
Cryptosporidium parvum is an enteric parasite that is one of the most common causes of diarrhea worldwide. It is transmitted through the fecal-oral route, often through contact with contaminated water. The oocyst stage of its life cycle is very resilient and can survive in water even after treatment. Infection occurs when an oocyst embeds itself in the gut epithelium. There is no cure for immunocompromised individuals who become infected.
The document discusses various sporozoan parasites including Sarcocystis, Cryptosporidium, Toxoplasma, Eimeria, Isospora, and Plasmodium species. It provides details on the parasite biology, life cycles, pathogenesis, clinical manifestations, diagnosis, treatment and prevention of diseases caused by these sporozoans. Key points covered include that sporozoans are obligate parasites with complex life cycles involving sexual and asexual reproduction, and they cause diseases by infecting tissues through ingestion of infective stages such as oocysts or sporocysts.
Trematodes are flatworm parasites that are dorsoventrally flattened and unsegmented. They have two suckers and incomplete digestive tracts. Blood flukes include schistosomes which have complex multi-host life cycles involving snail and human hosts. The three main types that infect humans are Schistosoma japonicum, S. mansoni, and S. haematobium. Lung flukes include Paragonimus westermani which uses crabs as an intermediate host. Intestinal flukes include Fasciolopsis buski, a large fluke found in the intestines, and Echinostoma ilocanum, known as Garrison's fluke, which
This presentation was given at the Delmarva Small Ruminant Conference All Worms All Day on December 8, 2018, in Keedysville, Maryland. The presenter was Susan Schoenian.
This document discusses the Taenia solium parasite, also known as the pork tapeworm. It has an adult stage that lives in the human intestine and a larval stage (cysticercus cellulose) that lives in pigs. The life cycle involves humans ingesting pork contaminated with the larval cysts, which develop into the adult tapeworm in the small intestine. Common symptoms in humans include abdominal pain, diarrhea and nausea. The larval cysts can also spread to other tissues like brain, eyes and muscles, causing neurocysticercosis with symptoms depending on the location of cysts. Diagnosis involves examination of stool samples or imaging tests, while treatment involves antiparasitic medications like albendazole
1. Entamoeba histolytica is one of the most important pathogenic protozoa that infects humans. It causes amebiasis through the transmission of infective cysts from feces to mouth via contaminated food or water.
2. The life cycle involves cyst ingestion, excystation in the small intestine, colonization of the large intestine by trophozoites, and formation of cysts that are passed in feces. Trophozoites can invade the intestinal lining and spread to other organs.
3. Symptoms range from mild abdominal discomfort to severe dysentery. Most infections are asymptomatic but some can cause life-threatening extra-intestinal complications like liver abscesses if left untreated
They have distinct cell nuclei and membrane-bound organelles which allow for compartmentalization and dedication of specific areas of the cell for specific functions.
Plays a very important role in the phylogeny of all eukaryotes.
They serve as the stem group for the fungi, plants, and animals.
Major groups within this kingdom include the algae, euglenoids, ciliates, protozoans and flagellates.
This document provides information about protozoa. It discusses that protozoa are eukaryotic, unicellular organisms that are either autotrophic or heterotrophic. They can reproduce asexually through binary fission or multiple fission, or sexually. The document categorizes protozoa into four major groups: flagellated protozoa, amoeboid protozoa, coccidea, and ciliates. It provides examples and details about different phyla and classes within these groups.
Parasitology is the study of parasites and parasitism. It explores aspects of parasite biochemistry, physiology, biology, and immunology. Key terms include: parasite, host, endoparasite, ectoparasite, reservoir host, vector, carrier, direct and indirect life cycles.
Helminthes are divided into three phyla: Nematodes (roundworms), Cestodes (tapeworms), and Trematodes (flukes). Important cestodes include Moniezia found in sheep and cattle. Key trematodes are Fasciola hepatica (liver fluke) and Paramphistomum (rumen fluke). Important nematodes are Haemonchus
Here are the answers to the flatworm quiz:
1. Phylum Platyhelminthes
2. Platy means “flat” and helminth means “worm”
3. Nephridium
4. Ecto or endoparasitic and few are free-living (usually aquatic)
5. Bilateral symmetrical
6. Non-parasitic flatworm respire through their body surface while parasitic worms absorb the host’s digested food through body wall.
7. Sexually and asexually
8. Body cavity and acoelomate
PART 2
1. Class Turbellaria - includes non-parasitic and aquatic flatworm (marine flatworm
This document discusses the classification and characteristics of cestodes or tapeworms. It focuses on Taenia saginata, the beef tapeworm. T. saginata has a scolex, neck and strobila segments. It can grow up to 10 meters long and infects humans through eating undercooked beef containing cysticerci larvae. The tapeworm attaches to the small intestine wall and releases proglottid segments containing eggs, completing its life cycle. Diagnosis involves detecting eggs or proglottids in stool and treatment uses praziquantel.
Mesozoa are microscopic worm-like parasites. This document discusses parasite taxonomy and classification. It covers the three major kingdoms that contain parasites: Protista, Metazoa, and Mesozoa. Within these kingdoms are phyla containing parasitic groups like Platyhelminthes (flatworms), Nematoda (roundworms), and Arthropoda. Flatworms are divided into classes like Trematoda (flukes), Cestoidea (tapeworms), and Turbellaria. Flukes have a complex life cycle involving snail intermediate hosts and produce larvae forms like sporocysts, rediae, cercariae and metacercariae. The document provides
1. The document discusses the classification of parasites, beginning with an overview of parasitology and definitions of key terms like parasite, host, and types of parasite-host associations.
2. Parasites are classified into three main phyla - Protozoa, Platyhelminthes, and Nemathelminthes. Protozoa are single-celled parasites while the latter two contain multicellular worms.
3. Key parasitic groups are described in more detail, including characteristics, examples of genera/species, and life cycles. This includes intestinal and tissue protozoa, cestodes, trematodes, and nematodes.
Ls2 afet unit 4 biodiversity of animals invertebratesThabo Bafana
The document discusses early embryonic development and classification of animals. It describes how most animals undergo cleavage and gastrulation after fertilization, forming a zygote, blastula and gastrula. It then classifies animals according to their body plan, including symmetry, tissues, and protostome vs deuterostome development. Major animal phyla are also summarized, such as sponges, cnidarians, platyhelminths, nematodes, arthropods and chordates.
Unit 4 biodiversity of animals invertebratesObey Maduna
The document discusses early embryonic development and classification of animals. It describes that most animals undergo sexual reproduction and embryonic development including cleavage, blastula formation, and gastrulation. It then classifies animals phylogenetically, noting key characteristics used for classification like symmetry, tissues, and protostome versus deuterostome development. Major animal phyla are summarized, including sponges, cnidarians, platyhelminths, nematodes, annelids, arthropods, molluscs, echinoderms, and chordates.
Unit 4 biodiversity of animals invertebrateshlengizwe10
The document discusses early embryonic development and classification of animals. It describes that most animals undergo sexual reproduction and embryonic development including cleavage, blastula formation, and gastrulation. It then classifies animals phylogenetically, grouping them into kingdoms, branches, grades, and phyla based on characteristics like symmetry, tissues, development, and body plan. Some of the major phyla discussed include porifera, cnidaria, platyhelminthes, nematoda, annelida, arthropoda, mollusca, echinodermata, and chordata.
This document provides information on various protozoan parasites that can infect humans, including Blastocystis hominis, Cystoisospora spp., Cryptosporidium spp., Cyclospora spp., Microsporidia, Toxoplasma gonii, Balantidium coli, Sarcocystis spp., and Babesia spp. For each organism, it describes characteristics such as morphology, life cycle, transmission, clinical symptoms, diagnosis, and treatment. It also includes images of organisms like oocysts, tissue cysts, and histopathological findings.
The document discusses early embryonic development and the biodiversity of animals, focusing on invertebrates. It describes how a zygote undergoes cleavage and forms a blastula through gastrulation. It then classifies animals into phyla based on their body plan, discussing characteristics like symmetry, tissues, and protostome vs deuterostome development. Major phyla include porifera, cnidaria, platyhelminthes, nematoda, annelida, arthropoda, mollusca, echinodermata, and chordata.
Parasites of Public Health Importance AAF 2021.pptxFeniksRetails
This document provides an overview of parasites of public health importance. It begins by defining key terms like parasite and parasitism. It then classifies parasites by their location in the host (ecto- or endoparasites) and discusses different types of host relationships. The document covers the taxonomy and classification of important parasite phyla like protozoa and helminthes. It describes modes of acquisition, disease mechanisms, and life cycles of major parasitic infections including malaria, amoebiasis, and African trypanosomiasis.
Classification Of Medically Important Helminths 2020.pptxZGHZ
This document provides an overview of medically important helminths (worms). It defines helminths and identifies their general characteristics such as a cuticle covering and life cycles involving egg, larval, and adult stages. The three main classes of helminths are described - trematodes (flukes), cestodes (tapeworms), and nematodes (roundworms). Examples are given for each class and where they typically infect, such as intestinal or tissue helminths. Key developmental stages like eggs, miracidium, and cercaria are also defined.
This document summarizes key characteristics of animals and describes experiments on invertebrates including sponges, cnidarians, flatworms, and parasitic worms. It discusses that animals are multicellular and heterotrophic, and most have digestive cavities. It also describes animal development including the zygote, blastula, and gastrula stages. Classification is based on characteristics like body plan, symmetry, germ layers, and presence of organs or tissues. Specific phyla discussed include Porifera, Cnidaria, Platyhelminthes, Trematoda, and Cestoda.
Internal parasites live within and feed off hosts, often in the intestinal tract, and can be life-threatening. There are three main types of helminths - nematodes, cestodes, and trematodes. Protozoa like Giardia, Entamoeba histolytica, and Coccidia also commonly infect poultry and other animals, potentially causing disease. Diagnosis requires identification of parasites, while treatment involves medication, hygiene practices, and sometimes surgery.
This document summarizes key patterns in animal development. It describes that animals undergo gastrulation where cells migrate to form germ layers and axes. Animals are categorized into 35 phyla based on features like germ layers, organ formation, and cleavage patterns. It describes that diploblastic animals have two germ layers while most are triploblastic with three germ layers. Triploblastic animals are further divided into protostomes and deuterostomes based on mouth formation. The document also provides examples of cleavage patterns in snails which are spirally arranged in either a dextral or sinistral pattern determined by maternal factors.
Similar to 1. Introduction to parasitology and 2. Flagellates (except hemoflagellates) by Dr. Himanshu Khatri (20)
Coronavirus Disease, officially named as COVID-19, started as an epidemic in a live animal market in Wuhan, China, and spread throughout the world at an alarming rate. It was declared a pandemic by WHO on 11th March, 2020. The virus causing the disease was initially named 2019 Novel Coronavirus (2019-nCoV), but later officially renamed by WHO as Severe Acute Respiratory Syndrome- Coronavirus 2 (SARS-CoV-2). This virus is related to SARS-CoV and MERS-CoV that caused epidemics in China and Saudi Arabia in 2002 and 2012, respectively. The virus primarily affects the lungs, and causes death in a small proportion of patients due to Acute Respiratory Distress Syndrome (ARDS). The data on this new disease is very early, and might change as new data emerges.
Disclaimer: The images used in this presentation do not belong to me.
This document discusses immunity and its types. It describes innate immunity as the first line of defense and includes factors like species, racial, and individual immunity. Innate immunity mechanisms are epithelial surfaces, antimicrobial substances, microbial antagonisms, cellular factors, inflammation, fever, acute phase proteins, and Toll-like receptors. Acquired immunity develops during life through infection or immunization and results in immunological memory and stronger responses. The document also defines key immunity terms and describes the differences between active and passive immunity.
Growth, nutrition, and metabolism of bacteria by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses bacterial growth, nutrition, and metabolism. It covers the bacterial growth curve with its four phases (lag, logarithmic, stationary, decline). Bacterial cell division occurs through binary fission. Generation time is the time for a bacterium to divide. Bacteria require water, carbon, nitrogen, and inorganic salts for nutrition and can be autotrophs or heterotrophs. Temperature, pH, oxygen levels, and other factors affect bacterial growth. Aerobic bacteria use oxygen for metabolism while anaerobic bacteria use fermentation.
Bio-medical waste (BMW) management rules (2016), by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses guidelines for managing biomedical waste according to the Biomedical Waste Management Rules of 2016. It defines biomedical waste as waste generated during diagnosis, treatment, or immunization of humans or animals. The most serious risk is from contaminated sharps. It identifies various sources of biomedical waste and categorizes waste types. The rules require waste segregation, staff training, and use of personal protective equipment. Waste must be segregated into yellow, red, white, and blue containers and then collected, transported, stored, treated, and disposed of properly to minimize health and safety risks.
This document discusses Plasmodium, the causative agent of malaria. It notes that Plasmodium belongs to the phylum Apicomplexa and has a life cycle involving both human and mosquito hosts. The life cycle involves sporozoites infecting the liver to form merozoites, which then infect red blood cells and undergo asexual reproduction to form more merozoites or gametocytes. Gametocytes develop into gametes in mosquitoes and fuse to form ookinetes and then oocysts, which rupture to release sporozoites that can infect new human hosts. The document provides details on the different species of Plasmodium, symptoms, diagnosis, and treatment
Antigen-antibody reactions can be observed in vitro as serological reactions which are used to identify and quantify antigens or antibodies. There are three stages of antigen-antibody reactions - primary, secondary, and tertiary. The sensitivity and specificity of serological tests are inversely proportional, with sensitivity referring to detecting small quantities and specificity only detecting complementary antigens and antibodies. Common serological reactions include precipitation, agglutination, complement fixation, neutralization, and immunoassays. Measurement of antigens and antibodies involves titration of serial dilutions.
Herpes Simplex Virus (HSV) and Varicella Zoster Virus (VZV) by Dr. Himanshu K...DrHimanshuKhatri
This document summarizes properties, types, and clinical features of Herpes Simplex Virus (HSV) and Varicella Zoster Virus (VZV). Both are DNA viruses that can cause latent infections. HSV causes oral and genital lesions and can rarely affect the nervous system, while VZV causes chickenpox and shingles. Laboratory diagnosis involves microscopy, virus isolation, and molecular methods. Treatment focuses on antiviral drugs like acyclovir. Vaccines exist to prevent chickenpox and reduce shingles risk.
General virology 5 - Antiviral agents, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses various types of anti-viral agents that target different stages of the viral lifecycle. It describes how antiviral drugs can inhibit early viral events, viral nucleic acid synthesis, viral integrase, viral protease, viral protein synthesis, and viral release. Specific drugs are outlined that target influenza, HIV, hepatitis B, hepatitis C, herpesviruses, and other viruses. Interferons are mentioned as inhibiting viral protein synthesis. The document provides detailed information on various nucleoside and non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and neuraminidase inhibitors used to treat viral infections.
General virology 4 - Laboratory diagnosis, by Dr. Himanshu KhatriDrHimanshuKhatri
Laboratory diagnosis of viral infections can be performed through several methods: (1) demonstrating characteristic cytopathic effects of viruses in cell cultures, (2) directly detecting viruses in clinical samples through electron or fluorescence microscopy, (3) isolating and culturing viruses in animals, eggs, or various cell culture systems, and (4) detecting viral antibodies through serological tests like ELISA, Western blot, or hemagglutination inhibition tests. Tissue culture using various cell lines is now the most widely used method for virus isolation. Laboratory diagnosis helps confirm viral infections, screen blood donations, and conduct epidemiological and research studies.
General virology 3 - Pathogenesis, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses the pathogenesis of viral infections through several stages:
1. Entry through respiratory tract, skin, eyes, digestive tract or mother-to-child transmission. Viruses breach barriers like mucus or skin.
2. Infection occurs at the primary site where viruses replicate and spread locally or through blood/lymphatics to secondary sites like liver/spleen.
3. Cellular changes include rounding, fusion or death of infected cells. Inclusion bodies containing virus may form inside or outside cells. Host responses fight viruses through immunity and fever.
General virology - Introduction, by Dr. Himanshu KhatriDrHimanshuKhatri
This document provides an overview of general virology. It discusses the properties of viruses including their inability to replicate without host cell machinery and resistance to antibiotics. Viruses have a protein coat called a capsid that protects their nucleic acids. They can be enveloped or non-enveloped. The viral life cycle involves attachment, penetration, uncoating, biosynthesis of proteins and nucleic acids, assembly, and release. Viruses can mutate or undergo recombination. They are classified based on having DNA or RNA and examples of virus families in each category are provided along with their key properties.
Epstein-Barr Virus (EBV) and Cytomegalovirus (CMV) by Dr. Himanshu KhatriDrHimanshuKhatri
This document summarizes Epstein-Barr virus (EBV) and cytomegalovirus (CMV), two herpesviruses that cause infectious mononucleosis. EBV infects B cells and epithelial cells and spreads through kissing or sharing items. It can cause infectious mononucleosis, tumors like Burkitt's lymphoma, or infections in immunocompromised individuals. CMV infects epithelial cells and glands and spreads through secretions, causing congenital infections or mononucleosis. Both viruses are diagnosed through antigen detection, isolation, and serology, with treatment focusing on symptoms.
Culture media and methods by Dr. Himanshu KhatriDrHimanshuKhatri
This document provides information on culture media and methods used to isolate and grow bacteria. It discusses the various constituents of culture media including water, electrolytes, peptones, agar, and extracts. It describes different types of media such as routine laboratory media, defined media, selective media, indicator media, and transport media. Various culture methods are outlined including streak plating, lawn culture, stab culture, and pour plating. Methods for culturing bacteria under anaerobic conditions such as the McIntosh and Filde's anaerobic jar and Gaspak system are also summarized.
1. Borrelia and Leptospira are spirochete bacteria that can cause relapsing fever and Lyme disease.
2. Borrelia is transmitted by ticks and body lice and causes relapsing fever, characterized by recurring fevers. Leptospira is transmitted by contact with contaminated water and causes Weil's disease, affecting the liver and kidneys.
3. Diagnosis involves microscopic examination of blood or urine to detect the spirochetes or serological tests to detect antibodies. Treatment includes antibiotics like doxycycline, penicillin, and tetracycline.
Bordetella is a genus of Gram-negative bacteria that includes the species Bordetella pertussis, which causes whooping cough. B. pertussis infects the ciliated respiratory epithelium and releases toxins like pertussis toxin and adenylate cyclase that damage tissues and cause symptoms. It is transmitted through respiratory droplets. Whooping cough progresses through catarrhal, paroxysmal, and convalescent stages. Diagnosis involves culture, molecular tests like PCR, or serology. Treatment is with erythromycin. Vaccines against pertussis include whole cell and newer acellular vaccines.
Bacterial taxonomy consists of classification, nomenclature, and identification of bacteria. There are two main approaches to bacterial classification - phylogenetic and Adansonian classification. Phylogenetic classification is based on evolutionary relationships while Adansonian classification considers overall similarities between organisms. Identification of bacteria can be done through microscopy, growth characteristics, and biochemical and genetic analysis. Scientific names provide a standardized naming system for bacteria while common names are more casual. A variety of culture and non-culture techniques exist to definitively identify bacterial species.
The document discusses the classification and characteristics of bacteria. It notes that bacteria are prokaryotic cells that lack organelles like the nucleus and Golgi apparatus. Bacteria come in various shapes (cocci, bacilli, spiral) and arrangements (chains, clusters). They have a cell wall containing peptidoglycan and may possess flagella, fimbriae or pili. Bacteria divide via binary fission and some can form spores. Gram-positive and Gram-negative bacteria differ in cell wall structure, with Gram-negatives also having an outer membrane containing lipopolysaccharides.
Bacterial genetics - Clinical applications, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses several topics in bacterial genetics and their clinical applications:
1. It describes mechanisms of inherent and acquired drug resistance in bacteria. Acquired resistance can occur through spontaneous mutation or horizontal gene transfer.
2. Molecular diagnostic methods like nucleic acid probes, PCR, and RFLP can be used to identify and type bacteria. PCR allows detection of small amounts of bacterial nucleic acids.
3. Genetic engineering techniques allow isolation of bacterial genes and production of useful proteins like insulin through recombinant DNA technology.
Bacterial genetics - Basic concepts, by Dr. Himanshu KhatriDrHimanshuKhatri
This document provides an overview of bacterial genetics concepts. It discusses how bacterial DNA differs from eukaryotic DNA in that it is not associated with histones and usually contains a single circular chromosome. It also describes mobile genetic elements like plasmids, transposons, bacteriophages, and pathogenicity islands that allow horizontal transfer of genes. The document outlines three main mechanisms of horizontal gene transfer - transformation, transduction, and conjugation. It also discusses how genetic variations in bacteria can occur through mutation or horizontal gene transfer, providing phenotypic and genotypic diversity.
Antigens are substances that stimulate the immune system to produce antibodies. The smallest part of an antigen that induces an immune response is called an epitope. Antigens can be proteins, polysaccharides, lipids, or nucleic acids. Antigens must be foreign to induce an immune response, as the body develops tolerance to self antigens. Antibody molecules bind specifically to antigens. Antibodies belong to five classes - IgG, IgA, IgM, IgD, and IgE - which have different structures and functions such as neutralizing toxins, activating complement pathways, and aiding phagocytosis. Abnormal immunoglobulins can indicate diseases like multiple myeloma or cryoglobulinemia.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
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5. Commensalism
• One species (usually smaller, called
commensal) derives food and shelter from the
other (usually larger, called host)
• Host is neither harmed or benefited
6. Parasitism
• One species (parasite) derives food and
shelter from another (host)
• But host is harmed
7. Groups of human parasites
• Protozoa
• Helminths
• Arthropods
All belong to eukaryota
8. Types of parasite
Endoparasite
- live inside the body of host
- they infect
- e.g. protozoa and helminths
Ectoparasite
-live on the surface of the body of host
- they infest
- e.g. arthropods
15. Flagella
1. Long thread like filaments
2. Seen in
i. Giardia lamblia,
ii. Trichomonas,
iii. blood flagellates like Leishmania and
Trypanosomes
16. Cilia
1. Short needle like filaments
2. Cover entire surface of the body
3. Seen in Balantidium coli
17. Stages of life cycle in protozoa
1. Trophozoite:
• It is an active form
• It is usually motile
• It can grow
• It can multiply
2. Cyst:
• (the protozoa is enclosed
within a tough wall)
• It is dormant form
• It is non-motile
• It cannot grow
• It cannot multiply
18. • The helminths are divided into 2 main groups:
1. Phylum Platyhelminthes
2. Phylum Nemathelminthes
19. Phylum Platyhelminthes
(Greek: platy=flat, helminth=worm)
• mostly hermaphrodite (monoecious) except
Schistosomes
• alimentary canal is incomplete or entirely lacking
• body cavity is absent
• when they are flattened, leaf like and
unsegmented, they belong to Class Trematoda
(trematodes)
• when they are flattened, tape like and
segmented, they belong to Class Cestoidea
(cestodes)
21. Phylum Nemathelminthes
(Greek: nematos=thread, helminth=worm)
• sexes are separate
(diecious)
• alimentary canal is
complete
• body cavity is present
• Phylum
Nemathelminthes has
only one Class
Nematoda (nematodes)
22. Stages of life cycle in helminths
1. Eggs (also called ova)
• Produced by adult forms
2. Larvae:
• Hatch out from eggs, either inside the host or in
the environment
• Are immature forms mature into adult forms
3. Adult forms:
• Mature from larval forms
• Produce eggs (oviparous) or larvae (viviparous)
23. Reproduction in parasites
Asexual multiplication:
-binary fission: one divides into two
-multiple fission (or schizogony): one divides
into many
Sexual multiplication: union of two cells
-conjugation: temporary union during which
genetic material is exchanged
-syngamy: sexually differentiated cells called
‘gametes’permanent unionform ‘zygote’
25. Type of host
Definitive host:
-for protozoa: in which sexual multiplication
takes place
-for helminths: in which adult form is present
Intermediate host:
-for protozoa: in which asexual multiplication
takes place
-for helminths: in which larval form is present
26. Types of life cycle
• Simple: in which there is only one host
• Complex: in which there is more than one
host
27. Exit forms
• When immune system gains upper hand
parasite transforms into exit forms reach
environment, vector or another host
28. Types of vectors
• Biological: in which the parasites multiply
• Mechanical: in which the parasites do not
multiply
36. Trophozoites
• They are pear shaped
• They are bilaterally symmetrical
• They measure 12-15 microns in length
• They are broad at anterior and taper at posterior end
• They measure 7-9 microns at their widest
• The dorsal surface is convex
• On the ventral surface, a disc is present (ventral disc)
37. Ventral disc
• The disc is bilobed and rigid
• It occupies most of the anterior part of the ventral
surface
• It is useful for attachment of the parasite to the
intestinal mucosa
39. Axostyles
• The trophozoite is supported by axostyles
• They are two in number
• These axostyles run between the two nuclei
longitudinally
• They run upto the posterior end
40. Median bodies
• There are two rod like structures present on
the axostyles posterior to the nucleus
• These are slightly curved
• They are called median or parabasal bodies
41. Flagella
• One pair of specialized ventral flagella for
attachment to the intestinal wall
• Three pairs of flagella which are dorsal
• Thus the organism has four pairs of flagella
• The trophozoites of G. intestinalis exhibit
motility resembling ‘falling leaf’
42.
43. Why G. intestinalis parasitizes the small
intestine?
• G. intestinalis requires phospho-lipids and
sterols for it’s growth
• But it is unable to synthesize them
• These substances are present in abundance in
small intestine
44.
45. Cysts
• The cysts are ellipsoid
• They measure 12 microns x 7 microns
• They have a well defined wall
• The wall is made up of chitin
• The mature cysts contains four nuclei
• It contains the axostyle and parabasal bodies as in
trophozoites
• It however contains only the remnants of flagella
• It does not have the disc
46. Life cycle
• It is simple i.e. it completes it’s life cycle in a single
host
• Mature cysts are infective forms of G. intestinalis
• Infective dose is 10 to 100 cysts
• Transmission is by fecal oral route
(Note: life cycle is very similar to E. histolytica)
47. Life cycle..2
• Excystation occurs in the proximal small intestine
• It is triggered by the action of pancreatic enzymes
• One cyst liberates two trophozoites
• The trophozoites attach to the intestinal mucosa by ventral
disc
• The feed by pinocytosis on the phospholipids and sterols
present in the small intestine
• They reproduce by binary fission
• When survival is threatened, encystations occurs
• Cysts can remain viable in soil and water for several weeks
• Trophozoites may be present in the feces, but they are not
infective
48.
49. Clinical features
• Most of the infections are asymptomatic
• In symptomatic cases, the incubation period is 1-3 weeks
• Symptoms include diarrhea, abdominal pain, bloating,
belching, flatus, nausea and vomiting
• It usually subsides within 10-14 days
• In chronic cases, multiple relapses may occur
• The patients have malabsorption, steatorrohea, and weight
loss
• It can impair growth in children
• It is one of the causes of traveler's diarrhea
50. Laboratory diagnosis
• The gold standard is the microscopic
examination of stool
• It may reveal trophozoites, cysts or both
• Trophozoites exhibit a typical ‘falling leaf’
motility
• The characteristic shape and two nuclei of
trophozoites are seen after staining the thin
fecal smear with Field’s stain
(Note: very similar to E. histolytica)
51. Laboratory diagnosis..2
• Cysts are often shed in feces in ‘showers’
• They may be present on one day and absent on the other
• Hence, it is advisable to examine atleast 6 stool samples
before ruling out giardiasis (In E. histolytica, at least 3 stool
samples are needed)
• The stool should be examined preferably after concentration
techniques
(Note: very similar to E. histolytica)
55. Prevention and treatment
• Not eating or drinking contaminated food and
water
• Adequate cooking
• Treatment is with Metronidazole
• Quinacrine is equally effective
56. Dientamoeba fragilis
• It does not have a flagella
• It uses pseudopodia for motility
• However, electron microscope has revealed
that it has characteristics of flagellates
• Hence, it is considered as a flagellate
57. Organism characteristics
• It exists only as a trophozoite (important!)
• Trophozoites have an average size of 8-12 microns
• They have a pseudopodium
• They have 2 nuclei (important!)
• Each nucleus have 4-8 chromatin granules (important!)
• The granules are centrally placed
• Very rarely, they may show ingested RBCs
62. Life cycle, pathogenicity and clinical
features
• Trophozoites are the infective forms (as they are the only
forms)
• However, it is not known how they survive in the external
environment
• The prevalence of D. fragilis is more in persons suffering from
pinworm (E. vermicularis) infections
• It is possible that eggs or larvae of pinworm facilitate the
transmission of D. fragilis
• The trophozoites live in the mucosal crypts of large intestine
• They do not invade the colonic mucosa
• Multiplication is by binary fission
• Most of the infections are asymptomatic
• When symptoms are present, they include intermittent
diarrhea, abdominal pain and anorexia
63. Laboratory diagnosis
• Stool microscopy reveals characteristic
trophozoites
• Fecal excretion rates vary
• Therefore several samples have to be
obtained
• The samples should be preferably obtained on
alternate days
64. Treatment
• Iodoquinol 650 mg tid for 20 days
• Paromycin 25-30 mg/kg/day in three doses for
7 days
• Paromycin is an aminoglycoside antibiotic
• Tetracycline 500 mg qid for 10 days
67. Organism characteristics
• It exists only as a trophozoite (like D. fragilis)
• Cysts are not formed
• Trophozoite is pear shaped
• It is 10-30 microns x 5-10 microns
• It has a single nucleus (important!)
• It has five flagella
• All arise at the anterior end
• Four flagella are free and one extends along the outer margin
forming an undulating membrane (fin-like extension)
• The undulating membrane reaches upto the middle of the
body
• It is anchored to a flexible rod
• This rod is called the costa
68. Organism characteristics..2
• It has an axostyle
• The axostyle supports the trophozoite
• It originates at the anterior end
• It then curves around the nucleus
• It extends posteriorly
• It extends beyond the body
69. Organism characteristics..3
• In fresh specimens, the trophozoites exhibit a
jerky motility
• They are resistant to changes in environment
• They survive in urine and damp towel for
several hours
• They can survive in water upto 40 minutes
70. Life cycle
• The trophozoite is the infective form (as it is the only
form)
• It lives in vagina and Bartholin glands in females
• In males, it lives in urethra, prostate, seminal vesicles
and edididymis (therefore the term vaginalis can be
misleading)
• The trophozoites divide by binary fission
• It is transmitted by sexual contact and fomites like
shared towels and underclothing
71. Pathogenicity and clinical features
• T. vaginalis produces trichomoniasis
• In females, it presents as vaginitis
• Incubation period is 4-28 days
• Manifestations are vaginal discharge
• Vaginal discharge is yellow and malodorous
• Vulval erythema and itching may be present
• It may also cause cervicitis
• In that case, examination with speculum may reveal
‘strawberry cervix’ (important!)
• In males, the infection is usually asymptomatic
• Some patients develop urethritis
• Rarely prostitis and epididymitis may result
73. Diagnosis
• Direct microscopy of the specimens reveal
motile trophozoites
• Specimens include vaginal or prostatic
secretions
• They may be accidently detected in urine also