Antibiotics and Germ Invasiveness Quiz

Microbiology Lectures Semester 1

• Bacterial Cell Structure
• Bacterial physiology
• Action of physical and chemical agents on bacteria
• Antibiotics and chemotherapy
• Bacterial genetics
• Microbial resistance
• Microorganism host relationship
• Pathogenicity and virulence
• Complement system
• Inflammation
• Immune Response
• Immunoglobulins
• Hypersensitivity
• Cells involved in Immune Response
• Study lecture notes as well as LP material

Bacterial Cell Structure - Lecture 1

• Bacteria are classified by cell wall type: rigid, flexible, or without a cell wall.
• Rigid bacteria have a thick cell wall and can form mycelia.
• Flexible bacteria have a thin cell wall.
• Bacteria without cell walls, such as Mycoplasma, lack cell walls.
• Bacterial shapes and sizes include cocci (spherical), streptococci (chains of cocci), staphylococci (clusters of cocci), enterococci (oval), pneumococci (lance-shaped), and diplococci (pairs of cocci).
• Rod-shaped bacteria include Enterobacteria and Bacillus Anthracis.
• Bacterial arrangement can be characteristic of some types of bacteria, such as staphylococci in clusters, streptococci in chains, and pneumococci in pairs.
• Some species are surrounded by a common capsule.
• Structure of a bacterial cell: capsule, cell wall, cytoplasmic membrane, cytoplasm, ribosomes, nucleoid (DNA), pili, plasmids, inclusion bodies, flagellum.

Structural Components of Bacterial Cells

• Constant Structures: cell wall, cytoplasmic membrane, cytoplasm (containing ribosomes, inclusions, vacuoles, plasmids, and possibly a nucleus).
• Facultative Structures: capsule, cilia (flagella), fimbriae (pili), spores.

Gram-Positive Bacteria

• Thick peptidoglycan layer.
• Teichoic acid/lipoteichoic acid present.
• Retain the crystal violet stain during Gram staining.

Gram-Negative Bacteria

• Thin peptidoglycan layer.
• Outer membrane containing lipopolysaccharides (LPS), proteins, and porins.
• Do not retain the crystal violet stain during Gram staining.

Roles of Bacterial Cell Wall

• Provides rigidity and shape.
• Aids in resistance to osmotic pressure.
• Involved in antigenicity and other roles in bacterial cell division.
• Target of some antibiotics.

Bacterial Physiology - Lecture 2

• Chemical constitution of bacteria
• Water: free water and water bound to other structures.
• Vacuoles: storage of water.
• Mineral substances: participate in regulation of osmotic pressure, contribute to enzymatic activity, and regulate pH and redox potential.
• Carbohydrates: simple carbohydrates for metabolism, complex carbohydrates for cell wall/capsule structure. (Biochemical tests are used for identification).

Bacterial Proteins, Lipids, and Pigments

• Proteins: simple and complex proteins (mucoproteins, chromoproteins, nucleoproteins).
• Lipids: less than 10%, can be free in vacuoles or combined as part of structures. Specific fatty acids (mycolic acids) are found in mycobacteria. Types of lipids include waxes and phospholipids.
• Pigments: found in cytoplasm, cell wall, or mucous layer. Can be chromophores (cytoplasmic pigments), parachromophores (cell wall pigments), and pigments found in the media. Pigments play important roles, including roles in antibiotic production and as enzymatic components, as well as roles in the protection from UV radiation.

Bacterial Enzymes

• Extracellular enzymes (exoenzymes) are hydrolytic enzymes.
• Intracellular enzymes are produced within the cell.
• Constitutive enzymes are always present.
• Inducible enzymes are synthesized only in response to specific compounds.

Bacterial Vitamins

• Some bacteria produce vitamins.
• Biotin, thiamine, riboflavin, vitamin B12, and B6 are some types.

Bacterial Growth Factors

• Some bacteria need certain factors for growth. Specific examples and their actions are identified.

Bacterial Metabolism - Lecture 14

• Bacterial nutrition: relation to energy sources (photobacteria, scotobacteria)
• Role of the sources used as synthesising materials- Autotrophic bacteria and heterotrophic bacteria.
• Parotrophic bacteria need energy from a host.

Bacterial Respiration - Lecture 15

• Aerobic respiration occurs in the presence of oxygen.
• Anaerobic respiration takes place in the absence of oxygen.
• Bacteria can be categorized as strictly aerobic, strictly anaerobic, or facultative anaerobic. A few are microaerophilic.

Bacterial Metabolic Pathways

• Carbohydrate metabolism
• Lipid metabolism
• Protein metabolism

Cultivation of Bacteria

• Clones: populations resulting from a single cell
• Strains: descendants of a single isolate
• Growth temperatures and requirements of bacteria

Culture Media

• Requirements for artificial media: nutritious, sterile, appropriate pH, osmotic pressure, and humidity.
• Different types of media: elective, enrichment, selective, differential

Isolated Colony - Lecture 18

• Method of obtaining isolated colonies through the streak plate method
• Stages of bacterial growth (lag, log, stationary, death)

Bacterial Morphology - Lecture 19

• Bacterial morphology
• Smooth and rough colony morphology

Microbial Action of Physical, Chemical, and Biological Factors - Lecture 20

• Sterilization: complete destruction
• Antisepsis: reduction of microbes
• Disinfection: reduction of microbes on surfaces
• Inhibition of growth or destruction of bacteria/microbes
• Physical factors: High/low temperature, filtration, non-ionizing and ionizing radiation, ultrasound, and osmotic pressure.

High/Low Temperature Sterilization

• Dry heat: incineration, oven
• Moist heat: boiling, autoclaving, tyndallization, pasteurization
• Low temperature: slow freezing, sudden freezing, lyophilization

Chemical Factors

• Antiseptics and disinfectants

Bacteriophages

• Structure: head, sheath, tail fibers, and basal plate.
• Types of relationships: lytic and lysogenic cycles.

Antibiotics - Lec 4

• Classification of antibiotics based on their modes of action (cell wall, cell membrane, protein synthesis, and nucleic acids)

Bacterial Genetics - Lec 5

• Mechanisms of genetic variation: mutation, genetic transfer, and recombination.
• Bacterial DNA structure and stability.

Bacterial Genome - Lec 6

• Essential and extrachromosomal genes.
• Replicons: plasmids, transposons, and bacteriophages and their functions.

Plasmids - Lec 7

• extrachromosomal genetic elements- replication mechanism- modes of transmission

Transposable Genetic Elements-Lec 8

• insertion sequence (IS)
• transposons (Tn)
• bacteriophages

Mechanisms of Bacterial Variability - Lec 9

• phenotypic and genotypic variations- mutation and genetic transfer

Antimicrobial Resistance - Lec 10

• definitions and mechanisms of resistance- types of resistance

Pathogenicity - Lec 11

• definition and factors affecting pathogenicity and virulence
• Multiplication and invasiveness
• Toxin production

Somatic Factors - Lec 12

• factors that allow germ multiplication and invasivness

Toxigenesis - Lec 13

• exotoxins, endotoxins

Organism Defense Against Infections- Lec 14

• Anatomical barriers, organ barriers, cells and components of inflammatory responses

Complement System - Lec 15-16

• System components in the classical, alternate, and lectin pathways
• Mechanisms of activation and action
• Role in different immune responses
• Cellular and chemical components

Immunity, Humoral Immune Response and Cellular Immune Response - Lec 17-18

• Innate and adaptive immunity
• Components and functions of both responses.

Hypersensitivity - Lec 19-20

• Types of hypersensitivity reactions
• Mechanisms, characteristics, and significance of each

Vaccines - Lec 21

• Active and passive immunity
• Classification of vaccines: monovalent, multivalent, and types based on preparation and components

Test your knowledge on antibiotics and their effects on bacterial growth and invasiveness. This quiz covers factors involved in germ multiplication, the action of antibiotics on ribosomal subunits, and the classifications of various antibiotics. Challenge yourself with questions about how different substances interact with bacterial protein synthesis.