Principles of Microbiology and Immunology PDF

Principles of Microbiology and Immunology Batch (45) Faculty of Pharmacy - Microbiology University of Gezira– Sudan November 18th / 2024 By: Dr. Sitelban...

Principles of Microbiology and Immunology Batch (45) Faculty of Pharmacy - Microbiology University of Gezira– Sudan November 18th / 2024 By: Dr. Sitelbanat Yassin Elsidig Ehaimir 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 1  Lecture Contents  Bacterial diversity  Bacterial Morphology:  Bacterial Structure  Bacterial internal and external structure 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 2 2  Bacterial Diversity 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 3  Bacterial Diversity Staining Growth Biochemical Host Structure Morphology reactions requirements reactions Simple/ Cell Simple Gram’s Shape stain stain O2 Complex nutrient wall Capsule Arrangemen t G+ve Flagella Size G-ve Spore 0.75- 4μm 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 4  Morphology 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 5  Morphology Arrangemen Shape t Spherical/ Simple Cocci Rod Spiral Simple Simple Oval stain Bacilli stain stain Coccus - Bacillus Sperillum Diplococcus – Vibrio - /Streptococ Bacillus Cocci -Bacilli Spirochetes cus Tetrade Cocco- bacillus Sarcina Strepro bacilli Staphyl Palisades 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd ococcus 6  Bacterial Structure Its important to know how to kill bacterial contaminants Bacterial Internal Bacterial External Structure Structure 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 7  Bacterial Internal Structure Inclusion granules Cytoplasmic Ribosomes membrane Bacterial Cell Wall Cytoplasm Plasmid Nucleiod 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 8  Bacterial External Structure Flagella Capsules & Slime layers Cell Surface Components Pilli Fimbriae 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 9  Structurally, typical Bacterium usually consists of: Cell Wall The bacterial cell wall maintain It is an obvious target for Chemically it is unlike the shape & rigidity of the antibiotics that can structure present in bacterial cell, to withstand attack & kill bacteria eukaryotic cell osmotic pressure without harm to the host 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 10  Murein Bacterial cell wall composed of peptidoglycan Glyco- peptide Mycoplasma Archea spp. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 11  Peptidoglycan It is a large macromolecule contained glycan (polysaccharide) chains cross-linked by short peptide bridges 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 12  The enzyme responsible for the peptide cross-linked of the murein Transpeptidase Inactivated by the β-lactam antibiotics. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 13  Glycan chain act as a backbone of peptidoglycan Composed of alternating (NAM) (NAG) N- acetyle glucoseamine N- acetyle muramic acid Dr. Sitelanat Yassin @ uofg.edu.sd 14 11/11/2024  Based on the cell wall structure Bacteria can be divided into two large groups G +ve G-ve 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 15  Comparison B/W G+ve & G-ve Feature G+ve G-ve Peptidoglycan 60-80% 10-20% Teichoic acid Present Absent Lipotechoic acid Present Absent Lipoprotein Abesnt Present Lipopolysaccharide Absent Present Protein c.15% c.60% Lipid c.2% c.20% Dr. Sitelanat Yassin @ uofg.edu.sd 16 11/11/2024 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 17  Removal of the cell G-ve bacteria with wall in G+ve damaged cell wall Lead to formation of become spheroplast protoplast even in non osmotic media. The G+ve can not maintain integrity when put in hypertonic or hypotonic media 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 18 Cytoplasmic Membrane The bacterial cytoplasmic The cytoplasmic membrane is membrane is a fluid phospholipid semipermeable and determines bilayer that encloses the bacterial what molecules enter and leave cytoplasm. the bacterial cell. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 19 Cytoplasm Cytoplasm or protoplasm Peptidoglycan subunits of a bacterial cell is a gel like matrix composed of Ribosomes The enzymes in the 80% water, enzymes, cytoplasm involved in the nutrients, wastes, gases, synthesis of: inorganic ions, and many DNA genome (nucleoid) low molecular weight compounds and cell Inclusion granules structures such as ribosomes, chromosomes (nucleoid), 11/11/2024 and plasmids. Dr. Sitelanat Yassin @ uofg.edu.sd 20 Nucleoid The nucleoid (meaning The DNA of most bacteria is nucleus-like) is an contained in a single circular irregularly shaped region molecule, called the within the prokaryotic bacterial chromosome. The cell that contains all or most chromosome, along with of the genetic material. The The nucleoid is essential several proteins and RNA chromosome of a prokaryote for controlling the molecules, forms an is circular, and its length is activity of the cell and irregularly shaped structure very large compared to the reproduction. It is called the nucleoid. This sits cell dimensions needing it to where transcription and in the cytoplasm of the be compacted in order to fit replication of DNA take bacterial cell place. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 21 Plasmid A plasmid is a small, often circular DNA Plasmids may transfer from molecule found in bacteria and other cells. one organism to another and Plasmids are separate from the bacterial between spp. there by chromosome and replicate independently of it. increasing the spread of They generally carry only a small number of resistance. genes, notably some associated with antibiotic resistance. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 22 Ribosome The bacterial ribosome is a They function as site ribonucleoprotein complex of about for bacterial protein 2.5 million Daltons, and is composed of synthesis two subunits that are named after their sedimentation values of 30S and 50S. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 23  Inclusion granules Found in the Formed when these material cytoplasm are replete in the environment To act as repositories of these nutrient Sulpher / Carbon Nitrogen phosphorus 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 24 Fagella The bacterial flagellum is a helical filamentous organelle responsible for motility. In bacterial species possessing flagella at the cell exterior, the long helical flagella filament acts as a molecular screw to generate thrust. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 25 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 26 Fimbriae A fimbria (Latin for 'fringe', plural fimbriae), also referred to as an "attachment pilus" by It is a short appendage some scientists, Fimbriae (also known as pili) found on many Gram- are proteinaceous structures that extend from negative and some Gram- the surface of many bacteria. These organelles positive bacteria, and that is mediate diverse functions associated with the thinner and shorter than a colonization of surfaces and virulence, including flagellum. adherence and biofilm 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 27  Pili Sex pili The pilus is a hair-like structure Conjugative pili allow for the associated with bacterial transfer of DNA between adhesion and related to bacteria, in the process of bacterial colonization and bacterial conjugation. infection.... The pilus is found on the surface of many Gram- positive bacteria and some Gram- negative bacteria. It is thinner and shorter than the flagellum. 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 28 Capsules and slime layers A slime layer is loosely associated with the bacterium and can be easily washed off, whereas a capsule is attached tightly to the bacterium and has definite boundaries.... Capsules can protect a bacterial cell from ingestion and destruction by white blood cells (phagocytosis) Slime Capsule It is usually Is an essential composed of virulence factor polysaccharides and it that protects the may serve to trap bacterium from nutrients 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd host defenses 29  II Good Luck 11/11/2024 Dr. Sitelanat Yassin @ uofg.edu.sd 30