Question

LO3: Summarize the concept of microbial antagonism (aka competitive exclusion) (BL2) and discuss the effect of antibiotics on the levels of normal microbiota or opportunistic pathogens (BL3)

Answer 1

Concept of microbial antagonism:

1. The inhibition of one bacterial organism by another. Generally normal bacteria flora of the body protect some defense against disease-causing organism.

2. It involves competition among microbes

3. Invasive bacteria growth is inhibition by antimicrobial compounds by native flora or competition for resources

4. For examples:

i. Microbial antagonism occur in large intestine E.coli produces bacteriocins. It closely or same related species such as salmonella shigella.

ii. Prevention of growth of candida at vaginal microbe biota

Effect of antibiotics on the level of microbiota

1. Disruption of existing microbiota it leads to antibiotic to break colonization resistant against clostridium, salmonella

2. Normal microbiota also causes opportunistic infection under certain conditions