01:447:390 Lecture Notes - Lecture 21: Dental Plaque, Virulence Factor, Biofilm
Document Summary
For lab practical, know gel electrophoresis- how to differentiate between selection and differentiation, know how to predict the sizes of the bands. Bacteria (and viruses) that initiate infection often adhere specifically to epithelial cells: mediated by interaction between molecules on the surfaces of the pathogen and the host cell, biofilms. Examples: slime layer (loose network), capsule (dense, well defined, sticky) Bacterial adherence can be: non-specific: extracellular macromolecules. Evasion of host immune system: specific interactions. Fimbriae and pili: fimbriated strains e. coli- urinary tract infections. Look at adherence proteins and lipotechoic acid in table. Streptococcus pyrogenes has m protein on the cell that binds to receptors on respiratory mucosa. Lipotechoic acid facilitates binding to respiratory mucosal receptor, along with m protein (look up at diagram of s. pyrogenes) Tale 23. 7: because of specific interactions, different pathogens have different tissue specificity. Infection requires attachment to surface (and to each other) for growth. Acidic glycoproteins from saliva and form a thin film.
