Terminology

Protozoan – single-celled eukaryote organisms.

Reservoirs – alternate or passive host or carrier harbouring pathogenic organisms, without injury to self. Can act as a source for others to infected.

Trophozoite – feeding stage of a protozoan

Cosmopolitan – having worldwide distribution

Gravid – with child; pregnant

Helminthe – worms

Nematodes – roundworms

Trematodes – flukes, flatworms

Cestodes – tapeworms

Hydatid – membranous sac filled with transparent fluid; formed by parasitic worms especially.

Unilocular – having only one internal cavity

Obligate – without another pathway

Pruritic – itchy

Papule – small, circumscribed elevation of the skin

Schizogony – division of cells (especially protozoans), in non-sexual stages of life history of organism

Tachyzoite – rapidly multiplying state in development of tissue phase of certain coccidial infections

Proglottis – one of the free, or nearly free, segments of a tapeworm. Contains male and female repro organs, can live a brief independent existence.

Hydatid sand – embryos of tapeworms in the fluid within a cyst

Oncosphere – first-stage larva of cestodes; emerging from egg and clawing through intermediate hosts intestine

• Protozoa (single cell eukaryotes)
• Helminths (worms)
• Arthropods (jointed appendages, chitinous exoskeleton)

• Amebae
• Flagellates
• Apicomplexa
• Ciliates
• Microsporidia

• Flatworms (flukes and tapeworms)
• Roundworms

• Insects (lice, flies, mosquitoes etc.)
• Arachnids (mites, ticks, spiders, scorpions).

• Definitive hosts harbor the adult or sexual stages of the parasite
• Intermediate hosts harbor the larval or asexual stages of the parasite
• Reservoir hosts maintain the life cycle of a parasite in the absence of humans.

• Symbiosis refers to organisms living together. Often both organisms benefit from this relationship.
• Commensalism is a symbiosis with one organism benefiting without causing harm to the other.
• Mutualism is a symbiosis where both organism benefit; lichens are an example of such an interaction.
  
• Parasitism is a symbiotic relationship where one organism (the parasite) benefits at the expense of the other (the host).

• Fecal examination for ova and parasites (O & P) performed on fresh material or preserved specimens. This examination must include permanent-stained slides and a concentration technique. Wet preparations may be used, but are not essential.
• Antigen detection systems that use ELISA or fluorescent antibody
• Thick and thin blood films usually stained with Giemsa stain
• Molecular techniques, including the polymerase chain reaction have been developed in experimental laboratories for identifying organisms in tissue, body fluids, and feces.

Category: Microbiology Notes