MIMG 100L #9 - The cell wall structure can be degraded by...

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The cell wall structure can be degraded by lysozyme secretions - present in tears & other secretions (part of the innate immune response). Cleaves backbone of peptidoglycan. The cell cannot resist osmotic pressure changes. Without intact cell wall, rod shape lost (protoplast). Subject to these changes Staphylococcus simulans: secretes Lysostaphin , which degrades cell wall structure. Breaks backbone link of peptidoglycan too. These species of staph attacks another species of staph. Penicillin : as bacteria is creating its cell wall, as peptidoglycan is forming, they need to be linked. Pen inhibits the cross chains from forming. Bacteria that divides and makes all of the proteins, attempts to make these cross chains and prevents that from happening. Compromises the integrity of the cell wall. whole thing falls apart. Bacteria dies. Affects gram positives, doesn’t work on gram negatives Griffith : Smooth strains vs Rough strains: Capsulated vs uncapsulated! Streptococcus pneumoniae: Smooth strain virulent. Inject into mouse, mouse dies. Rough strain nonvirulent, inject into mouse and mouse doesn’t die. Heat killed smooth strain injected, mouse lives. BUT heat killed smooth strain and rough strain, kills mouse because HGT of DNA material. Transfer of DNA from plasmid, gene encoding for capsule. Julius Adler: Led to understanding bacterial chemotaxis motility test medium demonstrates if cells can swim in a semisolid medium. A semisolid medium is inoculated with the bacteria in a straight-line stab with a needle. After incubation, if

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