Section IFundaments of MicrobiologyMacrobial GeneticsSHIHEZI UNIVERSITY
Section I Fundaments of Microbiology Macrobial Genetics SHIHEZI UNIVERSITY
KEY TERMSPhenotypeVirulent pahgeGenotypeTemperate phage PlasmidLysogenyBaceriophageLysogenic bacteriaMutationGeneralized transductionRecombinantSpecialized transductionHfr strainTransformationTransductionConjugationLysogenic conversionSHIHEZI UNIVERSITY
KEY TERMS Phenotype Genotype Plasmid Baceriophage Mutation Recombinant Transformation Transduction Conjugation Lysogenic conversion Virulent pahge Temperate phage Lysogeny Lysogenic bacteria Generalized transduction Specialized transduction Hfr strain SHIHEZI UNIVERSITY
GeneticsGeneticsdefines and analyzes heredity, or constancy and changein the physiologic properties of organisms.GeneThe unit of heredity, a segment of DNA that carriesgenetic information for a specific biochemical orphysiologic property Phenotypethe collective structural and physiologic propertiesofacell or an organism Genotypethe sequence ofDNA within a gene or the organizationof genesSHIHEZIUNIVERSITY
Genetics Genetics defines and analyzes heredity, or constancy and change in the physiologic properties of organisms. Gene The unit of heredity, a segment of DNA that carries genetic information for a specific biochemical or physiologic property Phenotype the collective structural and physiologic properties of a cell or an organism Genotype the sequence of DNA within a gene or the organization of genes SHIHEZI UNIVERSITY
Genetic Material in BatceriaChromosome (genome Plasmid Bactriophage (phage)Insert sequence (IS) / transposon (TnSHIHEZI UNIVERSITY
Genetic Material in Batceria Chromosome (genome) Plasmid Bactriophage (phage) Insert sequence (IS) / transposon (Tn) SHIHEZI UNIVERSITY
bacteriumplasmidbacterialchromosomeProkaryotic Genome Double-stranded, circular DNA1um Size: 580kb (mycoplasma) ~ 4,600kb (E. coli)Semi-conservative replication Pathogenecity island The pathogenic determinant genes are oftenclustered together in the DNA and are referred to aspathogenicity islands+Quite largeup to at least 200 kb+Code for many virulence genes, including adhesinsinvasins, exotoxins, and mobilizationSHIHEZI UNIVERSITY
Prokaryotic Genome Double-stranded, circular DNA Size: 580kb (mycoplasma) ~ 4,600kb (E. coli) Semi-conservative replication Pathogenecity island The pathogenic determinant genes are often clustered together in the DNA and are referred to as pathogenicity islands Quite large— up to at least 200 kb Code for many virulence genes, including adhesins, invasins, exotoxins, and mobilization SHIHEZI UNIVERSITY
Table 7-1. Comparison of genome sizes inseekaathndiruSize(kbp)OrganismProkaryotesArchae1660Methanococusjannaschi2180Archaeoglobus fulgidus580EubacteraMycoplasma genitalium820Mycoplasmapneumonide910Boreliaburgdoreri1040Chiamydia tachomatis1110Ricktsi prowazeki1140Treponema palldum1230Chiamyiapneumoniae1670Heliobacter pyori1830Hdemophilusinfuenzae2180Neiseria meningitidisserogroupA2270Nesria meningidisserogroup B4210Bacils sutlis4410Mycobacterum tuberculosis4640Escherichia oli48LambdaBacteriophageVariola186Viruses192Vaccinia229CytomegalovirusSHIHEZIUNIVERSITY
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Features of Plasmid Circular dsDNA<100kbGenetic infoGenes essential for bacterial growth are carriedon the chromosome, and plasmids carry genesassociated with specialized functionsRemoval / transferred Types: R, F, ViSHIHEZIUNIVERSITY
Features of Plasmid Circular dsDNA <100kb Genetic info Genes essential for bacterial growth are carried on the chromosome, and plasmids carry genes associated with specialized functions Removal / transferred Types: R, F, Vi . . . SHIHEZI UNIVERSITY
Table7-2.Examplesof metabolicactivitiesdetermined by plasmids.ActivityOrganismPseudomonaspeciesDegradation of camphortoluene,octane,salicylic acidBacilsstearothermophilusα-AmylaseAlcaligenes eutrophusUtilizationofHasoxidizabeenergy sourceEscherichia oliSucrose uptake andmetabolism,citrate uptakeKlesiellaspeciesNitrogen fixationStreptococcus (group N)Lactose utilization,galatose phosphotransferasesystem,citrate metabolismRhodosprilum rubrumSynthesis of photosyntheticpigmentFlavobacterium speciesNylon degradationSHIHEZIUNIVERSITY
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Plasmids Definition: Extrachromosomal geneticelements that are capable of autonomousreplication (replicon)Episome - a plasmid that can integrate intothe chromosomeSHIHEZIUNIVERSITY
Plasmids Definition: Extrachromosomal genetic elements that are capable of autonomous replication (replicon) Episome - a plasmid that can integrate into the chromosome SHIHEZI UNIVERSITY
Classification of Plasmids Transfer propertiesConjugativeNonconjugative Phenotypic effectsFertilityBacteriocinogenic plasmidResistance plasmid (R factorsSHIHEZI UNIVERSITY
Classification of Plasmids Transfer properties Conjugative Nonconjugative Phenotypic effects Fertility Bacteriocinogenic plasmid Resistance plasmid (R factors) SHIHEZI UNIVERSITY