Bacterial Classification, Structure, and Replication PDF

Bacterial Classification, Structure, and Replication Chapter 12 Differences Between Eukaryotes and Prokaryotes Three domains of life: * – Bacteria * – Archaea Prokaryotes * * – Eukarya animals pla...

Bacterial Classification, Structure, and Replication Chapter 12 Differences Between Eukaryotes and Prokaryotes Three domains of life: * – Bacteria * – Archaea Prokaryotes * * – Eukarya animals plants eukaryotes X fungi 1 Important to know Differences Between Eukaryotes and differences so that we the differences Prokaryotes can exploit for therapeutic benefits Major differences – bacterial chromosome single, double-stranded, ________ Circular molecule of DNA ~ 5 million base pairs – bacteria use a smaller ribosome 70S Louis is sos) – most bacteria have a cell wall I we do not have surrounding the plasma membrane to protect them against the environment – Gram + and Gram – Peptidoglycan _______________________ > We don't make peptidoglycan , - beta lactan drugs do Differences Between Eukaryotes and Prokaryotes 2  Characteristic Eukaryote Prokaryote Major groups Algae, fungi, protozoa, Bacteria plants, animals Size (approximate) >5 μm 0.5-3.0 μm Nuclear Structures Nucleus Classic membrane No nuclear membrane Chromosomes Strands of DNA diploid Single, circular DNA genome haploid genome Cytoplasmic Structures Mitochondria Present Absent Golgi bodies Present Absent Endoplasmic reticulum Present Absent Ribosomes 80S (60S + 40S) 70S (50S + 30S) (sedimentation coefficient) Cytoplasmic membrane Contains sterols Does not contain sterols Cell wall Present for fungi; Is a complex structure otherwise absent containing protein, lipids, and peptidoglycans Reproduction Sexual and asexual Asexual (binary fission) Movement Complex flagellum, if Simple flagellum, if present present Respiration Via mitochondria Via cytoplasmic membrane Bacterial Classification M. tuberculosis B. anthracis Macroscopic appearance colonial growth – ____________ color, size, shape, & smell – antibiotic resistance E. sakazakii Y. enterocolitica – fermentation – _____________ Hemolytic properties – hydrolyze lipids shadint Streptococcus spp. C. botulinum ↓ a CDC backnap is Group I dangerous for pregnant 3 women (can cause meningitis for babies)  Bacterial Classification Microscopic appearance – size – morphology __________ cocci __________ Dacilli (rods) spirillum spirochete – configuration -strep chonored -... clumps, chains, diplococci, ↓ d tetrads, etc. a – ability to retain the Gram stain Sarge Ge (+/-) ↓ Positive purple = retaining Iodine Bacterial Classification N. gonorrhoeae Streptococcus spp. V. cholerae T. pallidum chains/streptococci spirochete diplococci chain comma Vibrio Nocardia asteroides Actinomyces odontolyticus found in mouth branched/filamentous usually found - Immuno- regularly in compromised individuals X Y CDC 4  thidogma Bacterial Classification ↑ The Gram stain – rapid, powerful test that allows clinicians to distinguish between 2 : major classes of bacteria step and – diagnose and treat AlcoholAOnePTermembran ,Hans Christian Gram in Phol out Step : colores micropacteria CDC anything TB - saf Leporsy - E Coli -. How w & das a Bacterial Classification ambodies Metabolic, antigenic, and genetic distinction – metabolic signature: aerobic vs. anaerobic, E. coli O157:H7 nutrient requirements & biproducts, specific T enzymes usinga stomping automated Angen- – ____________: serotyping use of antibodies to detect antigens characteristic of a particular strain of bacteria organisms difficult to grow in the lab associated with specific disease syndromes (E. coli O157:H7) Food posioning - – analysis of genetic material (does not require living or growing organisms) & DNA hybridization PCR 3 just requires primer. Allows you to amplify CDC and study bacterial and 5  Bacterial Structure Cytoplasmic structures Yersinia pestis (the plague) – bacterial chromosome nucleoid transcription and translation coupled – _________: plasmids small circular, extrachromosomal DNA most commonly found in G- not usually essential for survival & _____________________ selective advantage – bacterial ribosome antimicrobial 305 + 50S 70S (_______________) resistence or – major drug target – cytoplasmic membrane electron transport & energy production membrane transport & secretion -attenuated notabanormally , to blood Reported Cases of Human Plague, United States 1970-2018 love hae his researcher - in smitted - Fran nig lab ↑ 9 CDC generalahuman 12 6  Human Plague Cases and Deaths, United States 2000-2018 CDC Bacterial Structure Cell wall Gram - Gram + – distinguishes G-/G+ – unique to bacteria – repetitive structures elicit innate protective immune responses – ______________ Peptidoglycan (PTG) 7  Bacterial Structure Gram + bacteria – thick, multilayered cell wall consisting mainly of PTG surrounding the cytoplasmic membrane ______________ protective porous – allows diffusion of metabolites essential for structure, replication, and survival degrades PTG lysozyme: enzyme in human secretions that _______________ ↓ – without PTG, bacteria succumb to osmotic pressure differences we contain in our secretions Bacterial Structure Gram + bacteria – teichoic acids s S water soluble, anionic polymers of polyol (polyribitol or glycerol) phosphates PTG Anchor covalently linked to the PTG to backnal essential for cell viability wall fatty acid – lipoteichoic acids – contain a _________________ cell anchored to the cytoplasmic membrane common surface antigens that distinguish bacterial serotypes and promote attachment act as a virulence factor 8  Bacterial Structure Gram + bacteria Listeria monocytogenes in forms a non-PTG sepirm form middle ↑ > - found in processed meats > - can naturally pass placenta CDC Bacterial Structure Gram – bacteria – structurally and chemically complex cell wall – 2 layers external to the cytoplasmic membrane thin layer of PTG ______________________ outer membrane – maintain bacterial structure – permeability barrier > difficulty - of antibiotic remedies – asymmetrical bilayer » outer leaflet composed of lipopolysaccharide (LPS) Periplasmic Space – __________________________ area between the external surface of the cytoplasmic membrane and the internal surface of the outer membrane contains components of transport systems and a variety of hydrolytic enzymes 9  honored 9 n. at HS ame -baramie Bacterial Structure genus A Gram – bacteria Neisseria meningitidis Bacterial Structure LPS: also known as _____________ endotoxin is a powerful stimulator of the immune system – activates B-cells (only cell in body that produces ? Immunity) – triggers release of cytokines from macrophages and dendritic cells IL-1, IL-6, TNF – induces fever want incr blood flow locally , but systemicly problemat – potentially shock we - Dic of BP – Shwartzman reaction disseminated intravascular coagulation (___________) Lipooligosaccharide (LOS) – shed from Neisseria spp. resulting in severe symptoms 10  Bacterial Structure Disseminated Intravascular Coagulation 11  Bacterial Structure Variety of proteins found in the G – outer membrane is limited Trimeric porin protein porins – ____________ allow the diffusion of hydrophilic molecules less than 700 Da through the membrane passage of metabolites and small hydrophilic antibiotics Bacterial Structure Gram – cell wall traversed by different Surface rendering of a Type III transport systems secretion system – Type I-V Gram provide mechanisms for the uptake and peptidog porousam release of different metabolites and other compounds thtransports Type III secretion system is a major virulence factor for some bacteria – acts as a syringe to inject proteins into other cells 12  Salmonella Has ispel us as sens Bacterial Structure phaco g g Bacterial Structure Streptococcus mutans External structures – capsules glyocalyx – slime layers ~ usually unnecessary for growth of excretion au poorly antigenic ju9 ______________________ anziphagocytic barrier promote adherence biofilm polysaccharide encased – ________: community of microorganisms " resistance to antimicrobials public health threat 13  internal devices medica substrator - Bacterial Structure Biofilm formation – Pseudomonas aeruginosa O a uprobleman d causes sepsis helps only and until WI antibiotic again ruptures device Bacterial Structure External structures Helicobacter pylori > - peptic vicers – flagella limed provide motility ______________ express antigenic and strain determinants ↓ O specific – E. coli O157H7 It from flagella - , – fimbriae (pili) C smaller numerous, hundreds Conjugation linsities promote adherence _______________ – adhesins specialized – conjugation IV type 14  bacter o my l ygram s Bacterial Structure cremures a runnin e Bacterial exceptions – Mycobacteria (acid-fast) Chlamydia trachomatis peptidoglycan arabinogalactan socan Stain mycolic acid ___________________ does – Chlamydia and mycoplasmas 9 > - no peptidoglycan cell wall Not ingobactera - plasms : no cell wall , Ihylmdia : No peptidog Bacterial Structure D 15  * Structure Chemical Constituents Plasma Phospholipids, proteins, and enzymes involved in membrane generation of energy, membrane potential, and transport Cell Wall Gram-positive bacteria Peptidoglycan Glycan chains of GlcNAc and MurNAc cross-linked by peptide bridge & Teichoic acid Polyribitol phosphate or glycerol phosphate cross-linked to peptidoglycan -Parallel Lipoteichoic Lipid-linked teichoic acid -attached acid to lipo Gram-negative bacteria Peptidoglycan Thinner version of that found in gram-positive bacteria Periplasmic Enzymes involved in transport, degradation, and space synthesis Outer Phospholipids with saturated fatty acids membrane Proteins Porins, lipoprotein, transport proteins LPS Lipid A, core polysaccharide, O antigen Other structures Capsule Polysaccharides (disaccharides and trisaccharides) and polypeptides Pili Pilin, adhesins Flagellum Motor proteins, flagellin Proteins M protein of streptococci (as an example) X Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Synthesis of PTG, LPS, teichoic acid, and glycocalyx occurs on the outside of the bacteria – away from synthetic machinery and energy sources of the cytoplasm and in an inhospitable environment – prefabricated precursors and subunits of the final structure are assembled on the inside and transported to the exterior bactopreno ____________________ (undecaprenol) for G – bacteria, outer membrane components are delivered through adhesion sites 16  Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Peptidoglycan (mucopeptide, murein) – rigid mesh made up of ropelike linear polysaccharide chains cross-linked by peptides – alternating series of two subunits N-acetylglucosamin (______) NAm joined subunits form glycan chain N-acetylmuramic acid (____) NAG Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall O Namarachech 17  Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Glycan chains held together by string of four amino acids – tetrapeptide chain attached to NAM L-alanine, D-glutamic acid, D-diaminopimelic acid, D-alanine generated ________________________________ D isomers not found in protein – protection against peptidases Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall * NAm has peplide chain attached * peptide bridge =gram positive (blu diamino- plmelic and D-Alanine) sunfresied * two D-alanine at the wir , a est W in end Glycine 18 Peptidogly can coils and cals cross link one another Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Peptidoglycan synthesis (1) glucosamine into Nam , then – glucosamine enzymatically converted to NAM, energetically activated need to "charge" via rxn col inco UTP Produces UDP-NAm by a reaction with UTP to produce UDP-NAM. bactoprenol (1) Pentapeptide is attached to – UDP-NAM-pentapeptide precursor assembled through a pyrophosphate link – UDP-NAM-pentapeptide is attached to bactoprenol through a pyrophosphate linkage, UMP is released NAG is added pentaglycine may be added – _____________________ bactopreno transa a the disaccharide:peptide precursor outside vova) the cell – NAM-NAG disaccharide is attached to the PTG chain 1 phosphate > 2 Phosphatss are too polar –ephosphates - pyrophosphobactoprenol is converted to phosphobactoprenol and to reenter the cell recycled – peptide chains from adjacent glycan chains are __________________ cross-linked 19  Peptidoglycan Synthesis aver gran crosslink a bastoprend-major · Swigglydois/ bactopreno NAG Spentaglycine Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Antimicrobial targets of PTG synthesis – MurA-F, Y, G Carrying charges out inside cell – transglycosylases ? – pyrophosphatases Inzumes – tanspeptidases (cross linking agent ⑤ for runs extracelicia D-carboxypeptidases penicillin binding proteins also known as) A PBPs f there medication are any D-Ala-D-Ala left Penicilian Dinds to these enzymes and breakdown => Inhibits cell wall production 20  Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall > - B-lactam drugs · penicillian · resembles D-Ala-D-Ala , aka Inhibit D- carboxy - peptidases Vancomycin > - · treats MrsA (resistant to Blactam · binds D-Ala-D-Ald so it doesn't allow for sell wall formation > - Bacitracin · too toxic for ingestion on the outside · traps pactoprene of > - thus it stops the recycling thus it inhibits bactoprenos is cell wall formation Structure and Biosynthesis of the Major Components of the Bacterial Cell Wall Lipopolysaccharide A – _________________ Lipid A · Lps endotoxn = responsible for endotoxin activity basic structure identical for related bacteria – core polysaccharide branched 9-12 sugars the same for a given species O-specific Antigen – _________________ long linear, 50-100 repeating units with 4-7 sugars/unit distinguishes serotype => serotyping for Ecoli 01570-speciac' 21  are the ps ? what LPS components ③ ② ① Cell Division Binary Fission __________________ – replication of bacterial chromosome – formation of a septum 22  spores can form positive only gram Spores Conversion from a vegetative state to a dormant state (_____) Spore – complete copy of the chromosome – high concentration of calcium bound to dipicolinic acid (keeps cell dehydrated) – protection heat, radiation, desiccation, enzymes, chemical agents Bacillus, Clostridium * Genu that can form spores Spores Neaed not Bacillus subtilis Neede go jo Clostridium botulinum weeda CDC &Diff : spores , resistant to antibiotics 23  Case Study The patient is a 20-year-old college student who presented to the emergency room at an outside hospital with general malaise, low-grade fever, and purplish discoloration on his face. The facial discoloration developed rapidly during the time from when he left his house to the time he arrived at the emergency room. Blood cultures were drawn and he was admitted to the intensive care unit. He was transferred to the University of Pittsburgh Medical Center with fever, disseminated intravascular coagulation and hypotension. Case Study The patient was given penicillin G, ceftriaxone, and rifampin. Despite maximum support the patient went into electromechanical disassociation and expired approximately 18 hours after initial presentation to the outside hospital. Diagnosis: Meningococcemia Nisseria Meningitidis (meningococcemial bacterial CSF menin ). diplococci CDC 24  Chapter 12 Bacteria : 1. Three domains of life Bacteria Archaea Eukary : , , a T IM prokaryotes m Planningi bactria categorized by small, Shape , Size-metabolic profile ability , to lyse enythrocytes, ability to hydroly lipids ferment sugars, resist antibiotics Eukaryote v Prokaryotes 3 major dassifications: Morphology Colony Configuration Gram vs Gram- nucleus Gagella - - ,. , Isozymes Nuclead/sing chi - - arc Gram staining Mitochondra cell wall - Heat x-> lodine - Crystal Violet- > acctone/alcohol : > > - Satin counter stain - Sor cell res -Deptidoglcad Gram ( ) + Gram)-( · 70s ribo (50s + 30.) > - thick DTG thin peptido , Outer membrane - cutoplasmic memb- ↓ Type I-U (Induced phagocytosis for cell respiration - techolanionic - Salmond es porins hydrolytic - , polymers of polyol phon) or) Incymes transport Type III /syringe + ~ In sten /lipotchoic Virulence factor major vivolence factor - Acid polsach LPS : - anchored to cell wall O-Anti [10 units I and Bacterial Community : Flagella antigen/strain determinants : 11) Glycocalyx (Capsule + Shime layers - E Coli. 0157 167 : poorly antigens Specific recognized - Hagallar type and phagocytic - by (2) Blohio-polysacchide encasedin (LPs) Immune sust ↓ resistant to anllmisco -. preudomonas aeruginosa Myobacteria-momotes , rather + or - Chancha = no Pta but contain arucolic acd= acid fast Mycoplasms - no cellmall purple - Arabinogglactan (strengthen, ex wall > -  mesh-like polymer system NAM-NAG Units connected by B1 4 glycosidic linkages Peptidoglycan of alter : , NAM-NAG I L-Alanine I D-glutamic add I diaminopimenc and 7 Dala