Microbes and Disease Name:_________

List 6 methods by which pathogens are transmitted and gain entry to the body

How are some of these diseases transmitted?

Athlete´s Foot:

Cholera:

Measles:

Malaria:

Syphilis:

Tetnus:

Case Study: Streptecoccus

Extracellular bacteria

damages tissues form outside cells

• Presence produces antibodies known as opsonins

• Produce acute diseases

-begin rapidly

-last a short time

-distinct symptoms

Virulence of Streptococcus

G +ve Strep-throat, tonsilitis, rheumatic fever, scarlet fever Produces virulence factors

-producd by plasmids

-cause pathogenicity

Case Study: Chlamydia

• Intracellular bacteria

-replicate in phagocytes or epithelial cells

• Causes chronic disease

-persists for a long time

• Developmental lifecycle of Chlamydia

Toxins

• Chemicals released by pathogen especially bacteria

• 2 types

-exotoxins e.g. Salmonella

-enterotoxins e.g. Clostridium tetani

More about exotoxins

3 main types

1. Toxins that act upon connective tissue

-allows further spread of bacteria and therefore infection of underlying tissues

-Staphylococcus aureus produces hyaluronidase

2. Toxins that act as enzymes

-enter cells and affect their metabolism

-Diptheria exotoxin

3. Membrane damaging toxins

-puncture cell membrane killing cells

-C. perfringens produces phospholipase that digests the plasma membrane