- •1.The basic properties of microorganisms. Factors ubiquitous of microorganisms
- •3.Major fields of theoretical and applied Microbiology
- •4.Major Characteristics of Eukaryotes and Prokaryotes
- •6.Sphere -haped bacteria. The variety of forms, their arrangement, examples, a brief description
- •7.Curved-haped bacteria. The variety of forms, their arrangement, examples, a brief description.
- •8.Plazma (cytoplasmic) membrane. Structure. Functions. Destruction of the plasma membrane by antimicrobial agents
- •9.Movement of materials across membranes. Simple diffusion. Facilitated diffusion.Osmosis.
- •10)Movement of materials across membranes. Active transport. Group translocation.
- •12.The Golden age of microbiology. The discoveries of Pasteur and Koch. Their significance for microbiology, biotechnology and medicine.
- •15. Bacterial cell envelop. The composition and functions of Bacterial Envelope.
- •17. Cell Wall of Gram negative bacteria. The Outer Membrane of Gram-negative Bacteria
- •Characteristics
- •18. Cell Wall-less Forms. Protoplasts. Spheroplasts. L-forms of the bacterium. Mycoplasma
- •19. Appendages structures of bacterial cell. Pili and fimbriae. Properties and functions of pili and fimbriae.
- •Key Concepts:
- •20. The structure and function of the bacterial flagella and axial filaments
- •21. Different arrangements of bacterial flagella. Flagella movement. Correlation of swimming behavior and flagellar rotation. Taxis
- •22. Glycocalyx structure. Capsules, slime Layers. Their functions
- •Vegetative reproduction. Budding. Multiply fission. The types of grown cycle. Asexual Reproduction of Actinomycetes.
- •Resting cell shape in prokaryotes. Cysts. Endospore. The structure and function.
- •Quorum sensing-social lives of bacteria. Biofilms. Cell-to-cell communication. Signalling molecules.
- •36 The interaction of the virus with the cell. Reproduction of viruses.
Key Concepts:
1)Noncovalent pilus polymerisation is a general mechanism of pilus assembly in Gram-negative bacteria, including the chaperon-usher assembly pathway and type IV pilus pathway, which generates noncovalent pilus polymers.
2)Sortase-mediated pilus assembly is a general mechanism of pilus assembly in Gram-positive bacteria that involves a transpeptidase enzyme named sortase, which cleaves pilin precursors at sorting signals between threonine and glycine and involve the side-chain amino groups of pilin motif sequences to generate covalent links between pilin subunits.
3)The sorting signal is consisted of an LPXTG motif followed by a hydrophobic domain and a positively charged tail.
4)The pilin motif is an 11 amino acid sequence of WxxxVxVYPKN located near the N-terminus of major pilin subunits, in which the electron donating lysine residue forms an isopeptide bond with the threonine residue generated from the cleavage of the LPXTG motif of adjacent pilin subunits.
5)Tissue tropism is referred to as the ability of a pathogen to adhere specifically to some particular epithelial cells.
6)Phase variation involves switching of surface antigens such as pili that allows a pathogen to evade the host immune system.
7)Immunomodulation is a process of changing the host's immune system by certain molecules known as immunomodulators including pili that can activate or suppress immune cells.
8)Dental plaque is one of the most complex bacterial biofilms that is formed by sequential colonisation of initial colonisers such as Actinomyces spp. and oral streptococci and late colonisers; this process involves Actinomyces fimbriae.
9)Twitching motility mediated by pili allows translocation between mucosal surfaces, colonisation of host tissues and establishment of biofilms by a pathogen. Fimbriae and pili are interchangeable terms used to designate short, hair-like structures on the surfaces of procaryotic cells. Like flagella, they are composed of protein. Fimbriae are shorter and stiffer than flagella, and slightly smaller in diameter. Generally, fimbriae have nothing to do with bacterial movement (there are exceptions, e.g. twitching movement on Pseudomonas). Fimbriae are very common in Gram-negative bacteria, but occur in some archaea and Gram-positive bacteria as well. Fimbriae are most often involved in adherence of bacteria to surfaces, substrates and other cells or tissues in nature. In E. coli, a specialized type of pilus, the F or sex pilus, apparently stabilizes mating bacteria during the process of conjugation, but the function of the smaller, more numerous common pili is quite different.
Common pili (almost always called fimbriae) are usually involved in specific adherence (attachment) of procaryotes to surfaces in nature. In medical situations, they are major determinants of bacterial virulence because they allow pathogens to attach to (colonize) tissues and/or to resist attack by phagocytic white blood cells. For example, pathogenic Neisseria gonorrhoeae adheres specifically to the human cervical or urethral epithelium by means of its fimbriae; enterotoxigenic strains of E. coli adhere to the mucosal epithelium of the intestine by means of specific fimbriae; the M-protein and associated fimbriae ofStreptococcus pyogenes (See Figure 2) are involved in adherence and to resistance to engulfment by phagocytes.