Adherence In Oral Bacteria BMS1-20 PDF

ADHERENCE IN ORAL BACTERIA Adhesion Descriptions p Adhesion n Attachment of an m.o to a host Adherence n Adhesion ability Adhesive Surfaces in Mouth p Surfaces that can bacteria attach in the mouth; n Keratinized epithelial cells n Non keratinized epithelial cells n...

ADHERENCE IN ORAL BACTERIA Adhesion Descriptions p Adhesion n Attachment of an m.o to a host Adherence n Adhesion ability Adhesive Surfaces in Mouth p Surfaces that can bacteria attach in the mouth; n Keratinized epithelial cells n Non keratinized epithelial cells n Hydroxyl apatite surfaces (tooth hard tissues and ceramic restorations) n Metal and acrylic surfaces of prothesis Bacterial Attachment Organelles p Fimbria (Pili) n Tip 1 n Tip 2 p Capsule p Flagella Bacterial Attachment Organelles p Bacteria; n Attachment to the host tissue with fimbriaa (pili) and capsule p Many oral pathogen attach to the mouth tissue with Fimbria p Type-1 fimbria n Inactivated when there is mannose in the environment n Many oral pathogens generaly have Tip-1 fimbria p Ex: Actinomyces and Porphyromonas gingivalis p Type-2 fimbria n Not inactivated with mannose found in the environment Fimbria p Proteus, Escherichia and Neisseria gonorrhoeae n Attach to urinary system multi layer epithelial cells with fimbria p Enteric rods n Intestinal villi and colon mucosa p A group beta hemolytic streptococci and Corynebacterium n Attach to tonsillar mocosa with host receptors that are appropriate for their fimbria Fimbria p Fimbria can bind to the appropriate receptors and/or they can also be attached to the surfaces without receptor Ex: Actinomyces: adhere to the enamel and prosthetic surface, bone tissue and hydroxyl apatite surfaces with their fimbriae C ve D group streptococci attach to tooth hard tissue with their fimbria Capsule p S. pneumoniae, K. pneumoniae, H. influenzae, N. meningitidis L. pneumophila n encapsulated bacteria n single layer cilial epithelial cells in respiratory tract system n Capsule mediated adhesion do not need specific receptor n pH, temperature, ion balance is essential/enough for adhesion Flagella p If bacteria have flagella, - Enhance invasion and spread within tissues Ex. Although Vibrio cholerae has a severe clinic (cholera) Non motile (no flagellum)) mutants can not attach to intestinal epithelium and are avirülant p Flagellum protein - Also enhance adhesion to host tissue n EX. Motile Spirochetes § Bacteria that reach to apical region from damaged periodontal membrane and starts retrograde pulpitis disease Adherence p Bakterial adherence is selective; n Ex: Streptococcus salivarius can not attach to tooth hard tissues n Streptococcus mutans can attach to tooth hard tissues whereas, it can not attach to the tonque surface p Veillonella parvum n İsolated mainly from tonque papillas Leptothrischia n isolated from cheek mucosas Streptococcus miteor, Vibrio, Fusobacteria and Spirochetes attach to spesific regions within mouth İmportant. No bacteria is found by chance in any flora!!! Adhesion p Bacterial adhesion, p Not only determine the bacterial virulance p But also determine which tissue will be infected p EX: Brucella, Salmonella, P. aeruginosa, Proteus and other enteric can not not attach to mouth tissues Porphyromonas gingivalis; n It attaches to keratin binding receptor of gingival epithelium in a short time n This makes bacteria an important oral pathogen S. marcescens, E. coli ve S. albus; n Even inoculate into mouth, can not attach and rapidly goes away (according to the studies) Adhesion Some factors affects bacterial adhesion in the mouth; p Desquamation of oral mucosa - Hundreds of cells lost every day from the surface layers of the epithelium - Bacterial loss with these cells p Bacteria float within saliva (108 CFUs) Generally; -The number of bacteria bind to each gingival epithelial cell (10-15) -The number of bateria on tongue surface 100 Oral Pathogens and Adhesion “The attachment of oral pathogens to oral tissues Attachment Types” 1. Specific Attachment Non Specific attachment Direct Attachment Indirect Attachment Adezin Criptotope Glukan Coaggregation bridge Specific Attachment Attachment of oral pathogens to oral tissues p Attach to oral mocosa epithelial cell surfaces; n Glycoprotein and glycolipid receptors n This receptors are immune meditator/ host attachment to their cells n There are complements on bacterial surfaces that can bind to these receptors p Bakteria use these surfaces molecules and p Attach easily, strongly, quickly, specificly, persistently to epithelium Ex. Attachment of Leptotrichia buccalis to cheek mucosa Attachment of M protein of A group Streptocci to pharynx and tonsils mucosas Non Specific Attachment “If bacteria do not have a specific receptor on tooth or oral mocosa surfaces, 2 phases play a role in adhesion” 1. First phase (adsorption phase): n Poor electrical charges between bacteria and host surface, first contact with van der Waals and surface tension forces n Hydrogen ion concentration (pH), temperature enhance this relation n Ex. Streptococcus miteor attach to tooth in acidic environment (pH