Question

Microbiology Final Assessment Preparation

Highlight the important concepts of microbe-human interaction in health and in infection and disease.

Outline and discuss the body’s immune system: 1st Line of Immunity, 2nd Line of Immunity and 3rd Line of Immunity (specific or acquired immunity).

Explain the phenotypic, genotypic, and immunologic methods to identify pathogens and diagnose infections.

Discuss in detail the structure and disease process of the pathogens associated with human disease including Gram (+) and Gram (-) cocci, Gram (+) and Gram (-) bacilli and miscellaneous bacterial pathogens.

Discuss in detail the structure and disease process of the pathogens associated with human disease including fungi, parasites, and viruses.

Discuss at least 3 important topics related to the course content for Modules 6-9 as a tool to prepare for the final assessment.

Answer 1

Immune system of body

1st line of defence:

a) Skin: The thick dead layer of epidermis acts as a physical barrier for pathogens.

b) Hair : Within nostril hairs prevent dust, pollutants and microbes to enter.

c) Mucous membrane and Cilia : Present in respiratory tract and trap foreign particles and propel those debrises out via throat.

d) Urine: Flush out microbes.

e)Acidic ph of stomach: Doesn't allow pathogens to survive.

f) Presence of good bacteria in intestine.

Second line of defence:

If pathogens enter within body nonspecific response is mediated. Often called in born or untrained immune response mechanism, proceed by phagocytotic cells: macrophages, neutrophils, dendritic cells, mast cells etc. They have patter recognising receptors(prr) that recognise certain molecular pattern associated with pathogenesis.

3rd line of defence:

This is a trained and specific response also called aquired or adapted, carried out by B-lymphocyte and T-lymphocyte. B and T cells are produced from bone marrow and thymus respectively and when encounter with antigens that particular B cell produce it's clones: called clonal selection and produce antibody that destroy antigens. T cells dont interact with antigens directly. Once antigen is processed and delived via MHC they activate cell mediated branch as well as humoral branch. Some B and T cell produce memory cells. If pathogens invade next time they recognise and attack within very short time duration.