1.

Candida albicans
- A dimorphic fungal parasite from the phylum Ascomycota, it exists as both yeast (unicellular,
budding form) and pseudohyphae/hyphae (filamentous form).
It is an opportunistic commensal parasite of humans, normally present on mucosal surfaces but
becomes invasive under immunosuppression
 Type: Fungus – Yeast (Opportunistic Dimorphic Fungus)
 Transmission: Endogenous (overgrowth of normal flora), direct contact, mucosal
 Infects/Causes: Oral thrush, vaginal yeast infections, systemic candidiasis
 Multiplication: Mucosal surfaces, bloodstream
 Reservoir: Human mucosa, GI tract, vaginal tract
 Source: Overgrowth due to immunosuppression, antibiotic use
 Antibiotic Sensitivity: Antifungals (Fluconazole, Amphotericin B, Echinocandins)
 Virulence Factors: Hyphae formation, adhesins, proteases, biofilm formation
 Symptoms: White patches in mouth, vaginal itching/discharge, fever (systemic)

2. Aspergillosis (Aspergillus spp.)

-A filamentous (mold) fungus in the phylum Ascomycota, forming long septate hyphae and producing
airborne conidia (asexual spores).
It is an opportunistic saprophytic fungus that becomes pathogenic when inhaled, especially in
immunocompromised hosts.
 Type: Fungus – Filamentous Mold (Opportunistic Pathogen)
 Transmission: Inhalation of airborne conidia (spores)
 Infects/Causes: Pulmonary aspergillosis, aspergilloma, invasive disease
 Multiplication: Lungs, paranasal sinuses, bloodstream
 Reservoir: Soil, decaying organic matter
 Source: Airborne spores from the environment
 Antibiotic Sensitivity: Antifungals (Voriconazole, Amphotericin B)
 Virulence Factors: Gliotoxin, proteases, catalases
 Symptoms: Cough, fever, hemoptysis, chest pain

3. Entamoeba histolytica
-A unicellular protozoan parasite in the class Lobosea (Amoebozoa). It uses lobopodia (blunt
pseudopodia) for movement and phagocytosis.
It’s an intestinal endoparasite, with an infective cyst form and a pathogenic trophozoite form,
capable of invading intestinal and hepatic tissue.Type: Protozoa – Amoebozoa (Intestinal Parasite)
 Transmission: Fecal-oral (cyst ingestion)
 Infects/Causes: Amoebic dysentery, liver abscess
 Multiplication: Colon (trophozoite stage), liver
 Reservoir: Infected humans
 Source: Contaminated food/water with cysts
 Antibiotic Sensitivity: Metronidazole, Tinidazole, followed by Paromomycin (luminal agent)
 Virulence Factors: Cysteine proteases, lectins, amoebapores
 Symptoms: Bloody diarrhea, weight loss, liver pain

4.Trichomonas vaginalis
- A flagellated protozoan from the class Parabasalia, it has five flagella and an undulating
membrane for motility.
It is an extracellular urogenital parasite, existing only as a trophozoite and surviving in anaerobic
vaginal or urethral environments.-
 Type: Protozoa – Flagellated (Urogenital Parasite)
 Transmission: Sexual transmission
 Infects/Causes: Trichomoniasis
 Multiplication: Urogenital tract (vagina, urethra)
 Reservoir: Humans
 Source: Infected sexual partners
 Antibiotic Sensitivity: Metronidazole, Tinidazole
 Virulence Factors: Adhesins, cytotoxic enzymes, immune evasion
 Symptoms: Vaginal discharge, itching, irritation, dysuria
5. Naegleria fowleri

- A free-living amoeboflagellate protozoan in the class Heterolobosea, it exhibits three stages: trophozoite
(infective), flagellate (transitional), and cyst.
It is a facultative parasite of the central nervous system, invading via the nasal mucosa and olfactory nerve.
 Transmission: Nasal inhalation of contaminated freshwater
 Infects/Causes: Primary Amoebic Meningoencephalitis (PAM)
 Multiplication: Brain tissue (especially olfactory bulbs)
 Reservoir: Warm freshwater environments
 Source: Lakes, hot springs, unchlorinated pools
 Antibiotic Sensitivity: Amphotericin B, Miltefosine (limited efficacy)
 Virulence Factors: Amoebostome, pore-forming proteins
 Symptoms: Rapid-onset fever, headache, seizures, coma, death

6. Trypanosoma cruzi & Trypanosoma brucei

- Both are blood and tissue protozoan flagellates from the order Kinetoplastida, characterized by
a kinetoplast (mitochondrial DNA granule).Type: Protozoa – Flagellates (Kinetoplastids)
 Transmission:
o T. cruzi: Feces of Triatomine bug (Reduviid bug)
o T. brucei: Bite of infected Tsetse fly
 Infects/Causes:
o T. cruzi: Chagas disease (cardiomegaly, megacolon)
o T. brucei: African trypanosomiasis (sleeping sickness)
 Multiplication:
o T. cruzi: Intracellular (cardiac/smooth muscle)
T. brucei: Bloodstream and CNS
 Reservoir:
o T. cruzi: Humans, wild mammals
o T. brucei: Humans, cattle, wild game
 Source: Infected insect vectors
 Antibiotic Sensitivity:
o T. cruzi: Benznidazole, Nifurtimox
o T. brucei: Suramin, Melarsoprol
 Virulence Factors: Immune evasion (antigenic variation in T. brucei), intracellular survival (T. cruzi)
 Symptoms:
o T. cruzi: Romana's sign, heart failure
o T. brucei: Fever, neurological decline, coma

7. Plasmodium vivax
- An obligate intracellular sporozoan protozoan in the phylum Apicomplexa, it has a specialized apical
complex for red blood cell invasion.
It completes a digenetic life cycle (in mosquito and human) and uniquely forms dormant hypnozoites in the
liver causing relapses.Type: Protozoa – Apicomplexan (Sporozoan, Blood Parasite)

 Transmission: Bite of Anopheles mosquito

 Infects/Causes: Vivax malaria (relapsing form)
 Multiplication: Liver (exoerythrocytic), red blood cells
 Reservoir: Humans
 Source: Mosquito vector
 Antibiotic Sensitivity: Chloroquine, Primaquine
 Virulence Factors: Schizogony, hypnozoite formation (dormant liver stage)
 Symptoms: Intermittent fever (every 48 hrs), chills, anemia

8. Toxoplasma gondii
- A facultative intracellular protozoan parasite also in phylum Apicomplexa. It exists as tachyzoites
(rapidly replicating), bradyzoites (tissue cysts), and sporozoites (from oocysts). It infects nearly all
warm-blooded animals but completes its sexual life cycle only in cats (definitive host).

 Type: Protozoa – Apicomplexan (Obligate Intracellular)

 Transmission: Ingestion of oocysts (cat feces) or tissue cysts (undercooked meat)
 Infects/Causes: Toxoplasmosis
 Multiplication: Intracellular (neurons, retina, muscles)
 Reservoir: Cats (definitive host)
  Source: Cat litter, raw meat
 Antibiotic Sensitivity: Pyrimethamine + Sulfadiazine, Spiramycin (pregnancy)
 Virulence Factors: Dense granule proteins (GRAs), ROP kinases
 Symptoms: Flu-like illness, brain lesions in immunocompromised, fetal damage

9. Trematodes (Flukes)
- Multicellular leaf-shaped flatworms in the class Trematoda (Phylum: Platyhelminthes).
They are hermaphroditic or dioecious endoparasites, with complex three-host life cycles involving snails
and vertebrates. They infect organs like the liver, lungs, intestines, or blood vessels.Type: Helminths –
Flatworms (Class Trematoda)

 Transmission:
o Ingestion of metacercariae (liver/lung flukes)
o Skin penetration (blood flukes – Schistosoma)
 Infects/Causes: Hepatobiliary disease, pulmonary disease, blood vessel inflammation
 Multiplication: Adult worms in human organs, eggs excreted
 Reservoir: Freshwater snails (intermediate), humans, fish, mammals
 Source: Contaminated water/plants/fish
 Antibiotic Sensitivity: Praziquantel
 Virulence Factors: Tegument enzymes, immune modulation
 Symptoms: Diarrhea, hematuria, hepatomegaly, eosinophilia

10: Taenia saginata & Taenia solium

-Segmented cestodes (tapeworms) in the class Cestoda, phylum Platyhelminthes. They have a scolex
(head) with suckers/hooks, and proglottids (segments) that mature and release eggs. T. saginata uses
cattle, while T. solium uses pigs as intermediate hosts. T. solium is also dangerous due to cysticercosis when
humans ingest eggs.Type: Helminths – Cestodes (Tapeworms)

 Transmission: Ingestion of larvae in undercooked beef/pork

 Infects/Causes:
o T. saginata: Intestinal taeniasis
o T. solium: Taeniasis and cysticercosis
 Multiplication: Adult worm in intestines; cysts in tissues (solium)
 Reservoir: Cattle (saginata), pigs (solium)
 Source: Infected meat
 Antibiotic Sensitivity: Praziquantel, Albendazole
 Virulence Factors: Scolex hooks/suckers, cyst formation
 Symptoms: GI discomfort, seizures (neurocysticercosis)

11. Ascaris lumbricoides

- A large cylindrical nematode (roundworm) in the phylum Nematoda, it is dioecious and exhibits
intestinal and pulmonary migration phases.
It is a soil-transmitted helminth, with infective eggs that become embryonated in the environment and are
ingested.
 Type: Helminth – Nematode (Roundworm)
 Transmission: Fecal-oral (ingestion of eggs)
 Infects/Causes: Intestinal ascariasis, lung migration
 Multiplication: Larvae migrate through lungs, adults in intestines
 Reservoir: Humans
 Source: Contaminated food/soil
 Antibiotic Sensitivity: Albendazole, Mebendazole
 Virulence Factors: Large size, immune evasion
 Symptoms: Abdominal pain, wheezing (Loeffler’s syndrome), malnutrition

12. Schistosomes (S. mansoni, S. haematobium, S. japonicum)

- Dioecious blood-dwelling trematodes (flukes) in the class Trematoda. Unlike most flukes, they have
separate sexes, and the female resides in the gynecophoric canal of the male. They infect mesenteric or
pelvic veins, and their eggs cause pathology due to tissue penetration and inflammation.

 Type: Helminths – Trematodes (Blood Flukes)

 Transmission: Skin penetration by cercariae in contaminated water

 Infects/Causes: Schistosomiasis
 Multiplication: No multiplication in human; adults in blood vessels, eggs cause pathology
 Reservoir: Humans, freshwater snails
  Source: Contaminated freshwater
 Antibiotic Sensitivity: Praziquantel
 Virulence Factors: Egg-induced inflammation, granuloma formation
 Symptoms: Hematuria (S. haematobium), portal hypertension (S. mansoni, S. japonicum)

13. Echinococcus
Cystic Echinococcus (CE):Known as Hydatid disease or Hydatidosis. It is caused by Echinococcus
Granulosus.. Usually found in liver and lungs but also can found in the other organ of the body
 Transmission: Ingestion of eggs from contaminated food/water (from dogs).
 Disease: Cystic Echinococcosis (Hydatid Disease)
 Symptoms: Abdominal pain, nausea, coughing, difficulty breathing (depending on the organ).
 Reservoir: Livestock (sheep, cattle, goats), wild herbivores.
 Source: Dogs, wolves, other canids (definitive hosts).
Alveolar Echinococcus (AE): Is it caused by Echinococcus Multilocularis. Often present as tumor-like
growths or cysts in the liver.
 Transmission: Ingestion of eggs from contaminated food/water (from foxes, wolves).
 Disease: Alveolar Echinococcosis
 Symptoms: Abdominal pain, jaundice, weight loss, cough, seizures (if brain is affected).
 Reservoir: Small rodents (e.g., voles, mice).
 Source: Foxes, wolves, other wild canids (definitive hosts).
Neotropical Echinococcus: It caused by two tapeworm species Echinococcus Vogeli (polycystic) and
Echinococcus Oligarthrus (unicystic)
 Transmission: Ingestion of eggs from contaminated food/water (from bush dogs).
 Disease: Polycystic Echinococcosis
 Symptoms: Abdominal pain, nausea, jaundice, liver enlargement.
 Reservoir: Rodents (e.g., capybaras, opossums).
 Source: Bush dogs, wild canids (definitive hosts).
 (all) Antibiotic Sensitivity: Albendazole; surgery needed for large cysts
 Virulence Factors: Cyst wall resistance, immune suppression
 Multiplication: Larval cysts enlarge in human tissue