Lecture Notes Flashcards

Flashcards covering key definitions and concepts from the lecture notes.

Antigenic Variation

Process by which some pathogens alter their antigens to avoid clearance by the immune system.

Factors Impacting Disease Transmission

Seasonality/climate, Presence of Vectors, Sanitation, Behavior, Water supply, Food

Impact of Global Warming on Malaria

Global warming may increase the distribution of the primary malaria agent and extend its possible distribution.

Altitude and Transmission

Malaria transmission varies with altitude (1355-2900 ft)

Malaria and Temperature Increase

Warmer years correlate with an increase in detected malaria parasites.

Environmental Contamination Prevention

Employing antiparasite drugs and sanitation methods.

Destruction of Free-Living Stages

This can be difficult considering Protozoan cysts, helminth eggs and infective larvae are often extremely resistant to toxic chemicals.

Prevention of Infection

Use of safe water supplies, meat inspection prevents taenia. Bednets prevents mosquito bites. Shoes stops hookworm larvae burrowing through the skin.

Malaria Elimination Targets

County (environmental modifications), Household (Indoor Residual Spraying), Couple (bed net), Person (drug treatment), Rare cases (active case management).

Transmission Blocking Vaccine

Vaccinate people so that they cannot transmit a parasite or virus to the mosquito so others cannot be infected

Pilin

A rod-shaped chain of polymerized subunits and is highly immunogenic where some bacteria such as E. coli and Neisseria ghonorrhoeae can change pili types – antigenic variation

Phase Variation

Individual gene switches between on and off states. Slipped-strand mispairing based on repeats can alter antigens presented by the bacteria

Antigenic Shift

Process by which two or more different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.

Trypanosoma Brucei Lifecycle

Transmitted via the Tsetse fly, leading to bloodstream trypomastigotes, which multiply by binary fission in body fluids

Antigenic Variation in Trypanosomes

Changing display of different antigens is called antigenic variation, which is an important form of immune evasion.

VSG

Variant surface glycoprotein presents on the surface as dimers where an outer domain is highly variable, and the only conservation detected is the position of cysteines.

Transcription in Trypanosomes

polycistronic, which means that a number of genes are transcribed at the same time into one long mRNA which further processing is needed.

Active VSG Genes

always at the “ends” of chromosomes (telomeres).

VSG Switching

requires physical transposition of a new VSG gene into the active expression site via intra- or inter- molecular recombination.

One var is expressed at one time

Allelic Exclusion

PfEMP1

P. falciparum Erythrocyte Membrane Protein 1 expressed in Only!

RNAi Machinery

Silences VSPs