Gram-Positive Pathogens PDF
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Uploaded by JovialStarfish
De Montfort University Leicester
Dr Rahmi Yusuf
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This document details lecture notes on Gram-Positive Pathogens. It covers learning outcomes, key features, and contents. The author is Dr Rahmi Yusuf, from De Montfort University, Leicester.
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Gram-Positive Pathogens Dr Rahmi Yusuf [email protected] HB1.03 Learning Outcomes Understand the structure of the Gram-positive cell wall - Key features of Gram positive cell wall - Difference with Gram negative - Appearance of cells upon Gr...
Gram-Positive Pathogens Dr Rahmi Yusuf [email protected] HB1.03 Learning Outcomes Understand the structure of the Gram-positive cell wall - Key features of Gram positive cell wall - Difference with Gram negative - Appearance of cells upon Gram staining Understand how Gram-positive bacteria are classified based on their ability to form spores (endo- and exo-) Understand features of bacteria that do not possess a cell wall [email protected] HB 1.03 Contents 1. Gram-positive cell wall 3. Non-sporulating Gram-positive 1.1 Bacterial cell envelope bacteria 1.2 Gram positive cell wall 3.1 Staphylococci 1.3 Peptidoglycan layer 3.2 Streptococci 1.4 Gram staining 3.3 Corynebacterium diphtheriae 1.5 Types of Gram positives 3.4 Listeria 2. Sporulating Gram-positive bacteria 3.5 Mycobacterium tuberculosis 2.1 Bacillus 4. Gram-positive bacteria without cell 2.2 Clostridiae wall 2.3 Streptomyces 4.1 Mycoplasmas: Mycoplasma & Spiroplasma 5. Gram-negative bacteria without cell wall 5.1 Chlamydia 5.2 Spirochetes [email protected] HB 1.03 1. Gram-positive cell wall [email protected] HB 1.03 1.1 Bacterial cell envelope [email protected] HB 1.03 1.2 Gram-positive cell wall Key features: Peptidoglycan layer (PepG) Teichoic acid Lipoteichoic acid (LTA) Proteins [email protected] HB 1.03 1.3 Peptidoglycan layer Unique to Bacteria 15 layers or more for G+ Strands of parallel glycan tetrapeptide (“peptidoglycan”) connected by peptide side chain [email protected] HB 1.03 1.4 Gram staining A method of differential staining invented by Hans Christian Gram in 1884 Primary stain is fixed within the peptidoglycan layer S. aureus (G+) B. cereus (G+, orange) E. coli (G-) P. aeruginosa (G-, green) [email protected] HB 1.03 1.5 Types of Gram-positives Based on biochemistry of nucleic acid, i.e., guanine to cytosine ratio: - High G+C (>50%) → Actinomyces, Bifidobacterium, Streptomyces, etc. - Low G+C (
