Bacterial Virulence Factors

• Some bacteria have certain cell parts that help them to invade other organisms better. These are called virulence factors.

• Some of these features are common to protists and fungi also.

• Can you recognise the ones shown on the next slide?

A

B

DCell Parts

Flagellum - motion

Cell Wall – protection, invasion, evasion

Ribosome – production of toxins/attachment proteins on cell wall

Cilia - motion

Spores

Gram’s Stain

Toxins

• Some bacteria produce toxins which can cause further damage to cells or disruption to cellular activities:– Eg. tetanus disease caused by infection with

Clostridium tetani which produces the tetanus toxin, causing all muscles to remain flexed by binding and blocking neurotransmitter receptors

– Eg. Botulism disease caused by food-borne infection with Clostridium botulinum which produces the botulinum toxin (botox) that relaxes nerves and prevents them from firing

Gram + bacillus

Gram - coccus

Giardia

Colonies

Growth Requirements

• Oxygen:– Aerobic– Anaerobic

• Nutrients– Sugar– Carbon– Minerals– Sulphur– Vitamins

• Moisture• Temperature

Reproduction

Binary Fission

Spores

Pili – genetic transfer/communication