Download Free Medical Bacterial Genetics PowerPoint Presentation

Bacterial Genetics PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : Check out this medical titled "Bacterial Genetics”.

This medical is about bacterial genetics, the study of genetic material, inheritance patterns, and gene expression in bacteria. Bacteria are single-celled organisms that reproduce through a process called binary fission, which involves the division of one cell into two identical daughter cells. Bacterial genetics is an important area of research because bacteria are responsible for many diseases, as well as being used in many important biotechnological applications.

One of the key features of bacterial genetics is the presence of plasmids, small circular pieces of DNA that can be transferred between bacteria. Plasmids often contain genes that confer antibiotic resistance or other advantageous traits, and their transfer can lead to the spread of these traits among bacterial populations. Bacterial genetics also involves the study of horizontal gene transfer, which is the transfer of genetic material between different bacterial species.

In addition, bacterial genetics involves the study of gene regulation, which refers to the mechanisms by which genes are turned on or off in response to different environmental signals. This is important because bacteria must be able to adapt to changing environments in order to survive. Bacterial genetics also includes the study of bacterial viruses, called bacteriophages, which can infect and replicate within bacterial cells and can play a role in genetic transfer between bacteria.

Overall, bacterial genetics is a broad and important field that encompasses many different aspects of the biology of bacteria. By understanding bacterial genetics, researchers can develop new strategies for treating bacterial infections and can also use bacteria for a wide range of biotechnological applications.

Tags : Bacterial Genetics, genetic material, inheritance patterns, gene expression in bacteria, Medical Genetics, Medical Genetics

Published on : Jun 01, 2023 | Views : 835 | Downloads : 0

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

Bacterial Genetics
Slide 2-

GENETICS-Study of genes their structure & function, heredity & variation Genomics-Study & analysis of nucleotides of DNA Nucleic acid-DNA and RNA
Slide 3-

Bacterial DNA Single Haploid Chromosome Super coiled circular dsDNA=1mm Exception: 2 chromosomes : Vibro cholerae
Slide 4-

Nucleotides-Structural units of Nucleic acids Nitrogenous bases-Purines(A,G) and Pyrimidines(T,U,C) Nucleoside Pentose sugar-Deoxyribose Phosphate group
Slide 5-

ppt slide no 5 content not found
Slide 6-

Bacterial DNA Ratio of A+T to G+C constant for each species Genetic information is stored as a code Codon-unit,triplet(3 bases) 64 codon 61 sense codon code for 20 AA AGA/AGG/CGA-arginine— code is degenerate 3 codon UAA/UAG/UGA- nonsense codons
Slide 7-

Gene or cistron Segment of DNA carrying codons for a particular polypeptide synthesis Locus a large no of genes Genome large no of loci Letter---------word-----sentence—paragraph--- Nucleotide—Codon-----Gene--------Locus--- 1000-3000 Gene 580 -5200 kbp length1-1.3mm
Slide 8-

DNA Replication: Bidirectional replication Rolling circle mechanism
Slide 9-

RNA mRNA rRNA tRNA
Slide 10-

ppt slide no 10 content not found
Slide 11-

Extra chromosomal elements Plasmids Free Circular dsDNA-In Cytoplasm for several generations Replicate independently Episome-integrated form Not essential for life of bacteria Number: up to 40/cell contain 50-100 genes
Slide 12-

Extra chromosomal elements Plasmids Curing: process of eliminating plasmid from bacteria Spontaneous induced Acridine Radiation Thymine starvation High temp
Slide 13-

Classification On the basis of ability to perform conjugation: Conjugative/self transmissible plasmid Non conjugative plasmid Based on compatibility b/w plasmid: Compatible Incompatible
Slide 14-

Classification Based on function: Fertility/F plasmid: contain tra gene: sex pili expression Resistance/R plasmid Col plasmid Virulence plasmid Metabolic plasmid
Slide 15-

Variation Phenotypic Genotypic
Slide 16-

MUTATIONRandom, heritable variation caused by alteration in nucleotide sequence of DNA Frequency 10-2 -10-10/bacterium/division CAUSES Spontaneous Induced (mutagen) – Physical: UV Chemical: alkylating agent, 5-FU, acridine dye
Slide 17-

Functionally affect: Not able to produce Capsule/flagella Antigenic structure alteration Altered sensitivity to Bacteriophage Drug resistance Altered pigment production Altered Biochemical reactions Altered colony morphology
Slide 18-

Types: Forward mutation Substitution Transversion: Transition:
Slide 19-

Types: Forward mutation Substitution Silent: New codon code for same AA Neutral: New codon code for functional equivalent AA Missense: Different AA Non-sense: Stop
Slide 20-

Types: Forward mutation Substitution Silent: New codon codes for same AA Neutral: New codon codes for functionally equivalent AA Missense: Different AA Non-sense: Stop
Slide 21-

Types: Addition or deletion Frame Shift Reverse Mutation True reversion
Slide 22-

Types: Reverse Mutation Equivalent reversion: 2nd Mutation different codon but same AA
Slide 23-

Types: Reverse Mutation Suppressor mutation: 2nd mutation in a different gene that revert the phenotypic effects of already existing mutation
Slide 24-

Demonstration of Mutation Gene sequencing Phenotypic changes Fluctuation test Replica plating
Slide 25-

Fluctuation test Luria and Delbruck-Mutation is SPONTANEOUS and RANDOM- Growth in presence of selective inhibitory pressure Bacteriophage and E. coli
Slide 26-

Replica plating-Auxotrophic mutant
Slide 27-

Ames Test (carcinogenicity testing) Mutational reversion assay Estimate Mutagenicity of mutant
Slide 28-

GENETIC TRANSFER Vertical Horizontal Transformation Transduction Lysogenic conversion Conjugation
Slide 29-

Transformation- Random uptake of free / naked DNA incorporation into chromosome Natural – S. pneumoniae express DNA-binding proteins on cell surface natural competent state allows uptake of "naked DNA"
Slide 30-

Transformation- random uptake of free / naked DNA incorporation into chromosome
Slide 31-

1928: Frederick Griffith (London): First demonstrated bacterial transformation
Slide 32-

An "S" or SMOOTH coat strain, which is lethal to mice.
Slide 33-

An “R" or rough coat strain, which is NOT lethal to mice.
Slide 34-

Griffith found that he could heat inactivate the smooth strain.
Slide 35-

heat-inactivated S strain, mixed with the R strain, the mouse would die. Thus there was some Material in the heat-killed S strain that was responsible for "transforming" the R strain into a lethal form.
Slide 36-

GENETIC TRANSFER Vertical Horizontal Transformation Transduction Lysogenic conversion Conjugation
Slide 37-

Transduction- Transfer of genetic material through bacteriophage
Slide 38-

ppt slide no 38 content not found
Slide 39-

Transduction 2 types: Generalized: Packaging error 3 outcome on transduction: Abortive transduction: 70-90% Stable gene transfer Unstable gene transfer
Slide 40-

Transduction 2 types:
Slide 41-

Transduction 2 types: Restricted/specialized Defect in disintegration of lysogenic phage 2 outcome when transduced to new bacteria Cross over Integrated as prophage
Slide 42-

Transduction 2 types:
Slide 43-

Importance of transduction Drug resistance: Pn resistance in Staphylococci Treatment: Genetic mapping, inborn error of metabolism Phage vectors used in molecular transformation of bacteria
Slide 44-

Lysogenic Conversion In Lysogenic bact prophage acts as additional segment of bact chromosome-new characters-lysogenic conversion eg. C.diphtheriae and its bacteriophage Phage coded Toxins: Diphtheria toxin cholera toxin Verocytotoxin of E. coli Streptococcus pyrogenic exotoxin A & C Botulism toxin C & D
Slide 45-

Lysogenic conversion: Phage DNA itself behave as new genetic element Transduction: Phage act as vehicle carrying bacterial gene
Slide 46-

GENETIC TRANSFER Vertical Horizontal Transformation Transduction Lysogenic conversion Conjugation
Slide 47-

Bacterial Conjugation Transfer of genetic information from one bacterium (donor or male) to another bacterium (recipient or female) bacterium by mating or contact with each other & forming conjunction tube
Slide 48-

ppt slide no 48 content not found
Slide 49-

F+ F- Mating HFR conjugation F’ Conjugation Col factor R factor-RTF + r determinants
Slide 50-

ppt slide no 50 content not found
Slide 51-

Colicinogenic (col) factor Bacteriocins are the antibiotic like substances produced by one bacterium that inhibit other bacteria Bacteriocins produced by coliform bacteria are called as colicin Bacteria other than coliforms also produce similar kind of substances e.g. pyocin, diphthericin
Slide 52-

ppt slide no 52 content not found
Slide 53-

FATE OF DONOR DNA:
Slide 54-

Bacterial Recombination Integration of Donor DNA to recipient chromosome General or Homologous Site specific
Slide 55-

General or Homologous Recombination b/w similar DNA sequences Reciprocal: Exchange of pair of Homologous DNA sequence b/w donor & recipient Non Reciprocal: Bacterial transformation Donor ssDNA is inserted into host chromosome & replace piece of host DNA
Slide 56-

Site specific Integration of bacteriophage DNA into Bacterial DNA is site specific Donor DNA not homologous with chromosome it joins
Slide 57-

TRANSPOSONS
Slide 58-

Genetic engineering Deliberate modification of organism genetic information by directly altering its genome Done using recombinant DNA technology Gene coding for desired property (protein) ---isolated from organism-----inserted to vector----cloned---desired property express
Slide 59-

ppt slide no 59 content not found
Slide 60-

POLYMERASE CHAIN REACTION Kary Mullis-1983 PCR is a DNA amplification system that produces a large amount of DNA in vitro from small amounts of starting material. It amplifies a specific DNA sequence (or gene) or interest. Primer mediated , temp dependant enzymatic amplification of specific target sequence to detectable levels
Slide 61-

Target DNA Primers Polymerase Enzyme- Thermus aquaticus Nucleotide Thermocycler
Slide 62-

Denaturation-940C Annealing of primers-50-600C Extension of primers 30-40 cycles for 3 hrs- 106 copies Detection-gel electrophoresis and ethidium bromide staining.
Slide 63-

ppt slide no 63 content not found
Slide 64-

PCR in Diagnosis Bacteria Viruses Fungi
Slide 65-

DNA PROBES Radiolabelled or chromogenically labelled pieces of ss DNA which can be used for the detection of homologous DNA by hybridization. Hybridisation is the technique in which two single-strands of nucleic acid come together to form a stable double-stranded molecule.
Slide 66-

Applications of DNA Probes In clinical microbiology : Direct detection of microbes in specimens To detect microbes which are difficult or impossible to culture Identification of culture isolates Strain identification To identify toxins, virulence factors Identification of resistant markers
Slide 67-

BLOTTING TECHNIQUES SOUTHERN BLOT WESTERN BLOT NORTHERN BLOT EASTERN BLOT
Slide 68-

Thank you Thank you
Slide 69-

Operons- An operon is a group of genes that are transcribed at the same time. Jacob, Monod & Lwoff They usually control an important biochemical process. They are only found in prokaryotes.
Slide 70-

Lac Operon The lac operon consists of three genes each involved in processing the sugar lactose One of them is the gene for the enzyme β-galactosidase (galactoside permease,transacetylase) This enzyme hydrolyses lactose into glucose and galactose
Slide 71-

E. coli can use either glucose, which is a monosaccharide, or lactose, which is a disaccharide However, lactose needs to be hydrolysed (digested) first So the bacterium prefers to use glucose when it can
Slide 72-

When glucose is present and lactose is absent the E. coli does not produce β-galactosidase. When glucose is present and lactose is present the E. coli does not produce β-galactosidase. When glucose is absent and lactose is absent the E. coli does not produce β-galactosidase. When glucose is absent and lactose is present the E. coli does produce β-galactosidase
Slide 73-

ppt slide no 73 content not found
Slide 74-

ppt slide no 74 content not found
Slide 75-

Sexduction Hfr F+
Slide 76-

Antibiotic: A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks.
Slide 77-

In 1926, Alexander Fleming discovered penicillin produced by fungi that inhibited bacterial growth. In 1939, Edward Chain and Howard Florey further studied penicillin and later carried out trials of penicillin on humans (with what were deemed fatal bacterial infections). Fleming, Florey and Chain shared the Nobel Prize in 1945 for their work which ushered in the era of antibiotic
Slide 78-

An antimicrobial is a substance that kills or inhibits the growth of microbes such as bacteria, fungi, or viruses. microbicidal or microbistatic.
Slide 79-

Chemotherapy Refers to treatment of disease by chemicals that kill cells, specifically those of micro-organisms or cancer
Slide 80-

Mechanism of action Penicillin Cephalosporins Vancomycin Bacitracin Polymyxin Colistin Aminoglycosides Tetracycline Chloramphenicol Macrolide Lincomycin Sulfonamides PAS INNH Trimethoprim Rifampin Quinolones Antimetabolites
Slide 81-

PABA Pteridine Dihydropteroate synthetase Dihydropteroic acid Di hydroFolic Acid Dihydrofolate reductase Tetrahydrofolate acid purines Nucleic Acid synthesis
Slide 82-

PABA Pteridine sulfonamides Dihydropteroate synthetase Dihydropteroic acid Di hydroFolic Acid trimethoprim Dihydrofolate reductase Tetrahydrofolate acid purines Nucleic Acid synthesis
Slide 83-

Selective toxicity An ideal antimicrobial agent should exhibit ST Drug is harmful to parasite without being harmful to host at the particular dose Receptor specific Biochemical event
Slide 84-

Mechanism of Drug Resistance NON GENETIC AND GENETIC NON GENETIC- Metabolically inactive/non multiplying M.orgs lose specific target site Drug unable to penetrate the site of infection
Slide 85-

Antimicrobial Chemotherapy Modern Chemotherapy-Paul Ehrlich(18450-1915)-arsenicals for syphilis and m.blue for malaria Domagk-1935-Prontosil Alexander Fleming-Penicillium notatum-Penicillin Antibiotic- Antimicrobial Chemotherapeutic
Slide 86-

GENETIC Mutation Transfer of genes Conjugation Transduction Transposition Transformation
Slide 87-

Drug Resistance Mutational Transferable Decreased permeability to drug/alt metabolic path/inactivating enzymes Single drug Low degree of resistance Not transferable Metabolically defective Virulence maybe lowered Combination of drugs useful Inactivating enzymes Multidrug High degree of resistance Transferable Metabolically normal No decrease in virulence -----------
Slide 88-

Biochemical mechanism of Drug resistance Production of enzymes that destroy the active drug Beta lactamases Adenylating/phosphorylating/acetylating Acetyl transferase Change of permeability Develop altered structural target Altered metabolic pathway Altered enzyme