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Bacterial Pathogens

Bacterial Pathogens. IMEC INC. Quick Learning Technique. WHAT STARTED MICRIOBIOLOGY. Louis Pasteur and MILK They even named this Bacteria after him—NAME IT?. General Bacterium. Reproduction of Bacteria. Most of the time bacteria go through Binary Fission

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Bacterial Pathogens

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  1. Bacterial Pathogens IMEC INC. Quick Learning Technique

  2. WHAT STARTEDMICRIOBIOLOGY • Louis Pasteur and MILK • They even named this Bacteria after him—NAME IT?

  3. General Bacterium

  4. Reproduction of Bacteria • Most of the time bacteria go through Binary Fission • Yet some can transfer genetic material viatransduction, transvection, conjugation and viral phage

  5. FTS Proteins

  6. Transduction

  7. Glycolysis • Most bacteria require energy just like eukaryotic cells via production of ATP • Glycolysis is the make form of ths production • Simple glycolysis is call the Emben-Meyerhof pathway

  8. Pentose Pathway

  9. Other energy forms • Alternative forms with with various common bacteria- The Pentose Pathway, also know as the hexo-monphosphate shunt • THE IS IMPORTANT WITH E-COLI & ENTEROCOCCUS • The next being very important as well, because some are common related NOSCOMIAL infections- The Entner-Dourdoroff pathway • PSEUDOMONAS

  10. BACTERIAL RESISTANCE • Cell Membrane/Cell Wall Structure • Flagella/Pili • Capsule Enzymes • Endospore state

  11. TOXINS • EXOTOXINS • Both Gram +ve/ negative organism • Plasmids, chomosomes, phage DNA • ENDOTOXINS • Gram Negative only • Only by plasmids

  12. Bacterial Pathogens • Small (0.5-3.0 um) size • Have no nuclear membrane • No micro-organelle (except ribosomes) • Small ribosomes with (70s)sub-unit: 50 S & 30S for protein synthesis • Have a single circular dsDNA(haploid) and a smaller circular plasmid

  13. REMINDERS

  14. Metabolism • Bacteria tends to be either aerobic or anaerobic in origin. This helps diagnostically and can sometimes be assimilated via a good history and physical

  15. Normal Flora • Skin---S. Epidermitis • Nose— S. aureus • Oropharnx—Viridans Strep • Colon— Fragilis.>E.coli • Vagina--Lactobacillus

  16. Common Causes of Pneumonia • Children • Viral (RSV) • Mycoplasma • Chlamydia • S. Pneumoniae • Young Adults • Mycoplasma • S. Pneumoniae • Adults over 40 • S.pneumoniae • H.Influenza • Viral

  17. Special Pneumoniae Groups • Aspiration • Anaerobes • Nosocomial • Staphylococcus. / P. Auriginosa/ Klebsiella • Neonatal • Group B Streptococci/ E.coli • Alcoholic • S. Pneumoniae • Immnocomprimised • Staphylococci, Gram (-ve), Pneumocystis in HIV

  18. Causes of Meningitis • Newborn • Group B Streptococci • E.Coli • Listeria • Children • S. pneumoniae • N. Meningitidis • Older than 6YO • N. Menengitidis • Enteroviruses

  19. Causes of UTI’s • Ambulatory • E.coli (50-80%) • Klebsiella (8-10%) • Staphylococcus saprophyticus (10-30% in young ambulatory women • Hospitalized • E-coli • Proteus • Klebseilla • Serratia • Pseudomonas

  20. Bacterial Pathogen Growth Phases • LAG PHASE • Turning on enzymes • LOG PHASE • Exponential Growth Phase • STATIONARY PHASE • Nutrients Used Up/Toxic products form • May also be due to pH • DEATH AND DECLINE

  21. BACTERIAL CLASSIFIED • GRAM STAIN • MORPHOLOGY • Organism, Colony in Culture • METABOLIC CHARACTER • Hemolytic Property, Nutritional requirements • SEROLOGY • Genetic make-up, Phage typing,

  22. BACTERIAL GENETICS • DNA • Purines (Adenine) & (Guanine) • Pyrimidine (Thymine) & (Cytosine) • The bacterial Chromosome is a dsDNA loop without a membrane • Only One Copy (HAPLOID) • Multiplication by Binary Fision

  23. BACTERIAL GENETICS • PLASMIDS • Extra chromosomal genetic material not needed for bacterial growth- • Can replicate by themselves • Mostly Circular dsDNA • Some may be linear • Transmitted via F-Pili by Conjugation • R-plasmid similar to F • Can induce a resistance as in E-Coli

  24. BACTERIAL GENETICS • VIRULENCE PLASMIDS • Transfer Virulence Factors • Example • E-COLI: LT & ST TOXINS • STAPH AUREUS: SSS • STEPTOCOCCI: HEMOLYSIN

  25. BACTERIAL GENETICS • BACTERIOPHAGE • Contains Head • Sheath capsid • Tail Fibers • PHAGE IS SPECIFIC TO BACTERIA, AND BACTERIA MUST BE IN PROPER RATIO

  26. Phage Assembly

  27. BACTERIAL GENETICMATERIAL EXCHANGE • TRANSFORMATION • Only occurs in a few Genera- • Usually between same species • FREES DNA RELEASE • TAKEN UP BY ANOTHER • EXAMPLE: • (Hemophilus, strep.Pneumonia)

  28. BACTERIAL GENETICMATERIAL EXCHANGE • TRANSDUCTION • Specialized via temperate phage • Integrated then spliced out • Generalized via virulent phage • Transfer of DNA through Phage

  29. BACTERIAL GENETICMATERIAL EXCHANGE • CONJUGATION • THIS IS TRANSFER VIA SEX PILI • Donor (F+)/ Recipient (F-)

  30. Sex Pili of E-Coli

  31. Polysaccarhide Information • Bacterial surface or secreted polysaccharides are molecules that can function as barriers to protect bacterial cells against environmental stresses, as well as act as adhesins or recognition molecules. In some cases, these molecules are immunodominant antigens eliciting a vigorous immune response, while in other cases the expression of polysaccharides camouflages the bacteria from the immune system. Until recently, most studies on the enzymatic steps and regulation of these molecules were performed on the enteric gram negative bacteria Escherichia coli and Salmonella typhimurium. With the advent of modern bacterial genetics, techniques such as construction and characterization of polysaccharide mutants, cloning of genes and complementation of these mutations, and expression of polysaccharides in heterologous bacterial hosts has prompted investigations into the roles and functions of these molecules for many different bacteria.

  32. BACTERIAL CLASSIFIED • Other factors for Gram Positive+ • Cocci • Catalase Positive-Staph • Catalase NegativeStrep • Bacillus • Spore forming • Bacillus (aerobic) • Clostridium (anaerobic) • Non Spore forming • Cornyobacterium (non motile) • Listeria (motile)

  33. GRAM-POSITIVE (+) ORGANISMS

  34. GRAM POSITIVE • Contain Cell Envelope with a Rigid Cell Wall and a lipid bilayer cytoplasmic membrane • Cell Wall is made of Petidoglycan layer (Thick) with Teichoic acid • Peptidoglycan is made of polysaccarrides (N-acetyl glucosamine & acetyl muramic acid) • Which is covered interwoven with Lipoteichoic Acid • Thicker and Three dimensional compared Gram (-)

  35. GRAM POSITIVE WALL

  36. PEPTIDOGLYCAN

  37. Staphylococci aureus Staphylococci epidermidis Staphylacoccus sp (coagulase negative) Streptococcus pneumoniae (viridans group) Streptococcus agalactiae Streptococcus pyogenese Enterococcus AerobicGram Positive Cocci

  38. GRAM (+) STAPH

  39. STAPH AUREUSSmall Clusters

  40. Staphylococcus aureus • Illness caused • Food Poisoning • Pneumonia (often nosocomial) • Other possibilities • Skin and integumentary infections , Bacteremia, Toxic Shock Syndrome , Meningitis ,Osteomyelitis ,Renal abscess • Endocarditis ,Septic arthritis ,Impetigo • Description • Gram positive • Cocci (grape-like clusters) • Facultative anaerobes • Non-spore-forming • Non-motile • Normal human flora • When growth occurs in prepared food, enterotoxins are produced that cause food poisoning. • Symptomology • Food Poisoning symptoms (symptoms occur between 2 to 4 hours after ingestion) • Diarrhea ,Nausea ,Vomiting ,Self limiting • CAUSES • Unsanitary food handling by colonized or infected food handlers • Improper refrigeration following contamination • Associated foods • Custards or custard-filled pastries • Dairy products • Meats • Potato salad • Salads • Pneumonia symptoms • Chest pain ,Cough • Severe shaking chill • Sustained fever • Area and seasonality IV DRUG USERS • Inhalation of droplets

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