Chapter 21Q&AStructure and Function of the SkinThe Structure of Human SkinMucous MembranesPowerPoint PresentationNormal Microbiota of the SkinSlide 8Slide 9Slide 10Microbial Diseases of the SkinSkin LesionsBacterial Diseases of the SkinStaphylococcal Skin InfectionsStaphylococcus aureusStaphylococcal BiofilmsSlide 17Nonbullous Lesions of ImpetigoScalded Skin SyndromeLesions of Skin SyndromeStreptococcal Skin InfectionsSlide 22Slide 23Invasive Group A Streptococcal InfectionsStreptococcal Toxic Shock SyndromeInfections by PseudomonadsBuruli UlcerClassifications of AcneComedonal AcneInflammatory AcneNodular Cystic AcneSlide 32Viral Diseases of the SkinWartsPoxvirusesSmallpox LesionsChickenpoxSlide 38ShinglesSlide 40Herpes SimplexCold Sores Caused by Herpes Simplex VirusHSV-1 in the Trigeminal Nerve GanglionSlide 44Measles (Rubeola)Slide 46Reported U.S. Cases of Measles, 1960–2007Rubella (German Measles)Fifth DiseaseRoseolaSlide 51Diseases in Focus: Macular RashesDiseases in Focus: Vesicular and Pustular RashesFungal Diseases of the Skin and NailsCutaneous MycosesDermatomycosesSlide 57Slide 58Subcutaneous MycosesCandidiasisCandida albicansCase of Oral CandidiasisSystemic CandidiasisSlide 64Slide 65Parasitic Infestation of the SkinScabiesPediculosis (Lice)Slide 69Diseases in Focus: Patchy Redness and Pimple-Like ConditionsMicrobial Diseases of the EyeBacterial Diseases of the EyeSlide 73Slide 74Slide 75TrachomaSlide 77Other Infectious Diseases of the EyeSlide 79Slide 80Slide 81Diseases in Focus: Microbial Diseases of the EyeCopyright © 2010 Pearson Education, Inc.Lectures prepared by Christine L. CaseChapter 21Microbial Diseases of the Skin and EyesCopyright © 2010 Pearson Education, Inc.Q&AHow does the morphology of Candida albicans contribute to the microbe’s pathogenicity?Copyright © 2010 Pearson Education, Inc.Structure and Function of the Skin21-1 Describe the structure of the skin and mucous membranes and the ways pathogens can invade the skin.Learning ObjectiveCopyright © 2010 Pearson Education, Inc.Perspiration and sebum contain nutrientsSalt inhibits microbesLysozyme hydrolyzes peptidoglycanFatty acids inhibit some pathogensFigure 21.1The Structure of Human SkinCopyright © 2010 Pearson Education, Inc.Mucous MembranesLine body cavitiesThe epithelial cells are attached to an extracellular matrixCells secrete mucusOften acidicSome cells have ciliaIn eyes, washed by tears with lysozymeCopyright © 2010 Pearson Education, Inc.Check Your UnderstandingThe moisture provided by perspiration encourages microbial growth on the skin. What factors in perspiration discourage microbial growth? 21-1Copyright © 2010 Pearson Education, Inc.Normal Microbiota of the Skin21-2 Provide examples of normal skin microbiota, and state the general locations and ecological roles of its members.Learning ObjectiveCopyright © 2010 Pearson Education, Inc.Normal Microbiota of the SkinGram-positive, salt-tolerant bacteriaStaphylococciMicrococciDiphtheroidsFigure 14.1aCopyright © 2010 Pearson Education, Inc.Normal Microbiota of the SkinGrow on oilsAerobes on surfaceCorynebacterium xerosisAnaerobes in hair folliclesPropionibacterium acnesYeastMalassezia furfurCopyright © 2010 Pearson Education, Inc.Check Your UnderstandingAre skin bacteria more likely to be gram-positive or gram-negative? 21-2Copyright © 2010 Pearson Education, Inc.Microbial Diseases of the SkinExanthem: Skin rash arising from another focus of the infectionEnanthem: Mucous membrane rash arising from another focus of the infectionCopyright © 2010 Pearson Education, Inc.Skin LesionsFigure 21.2Copyright © 2010 Pearson Education, Inc.21-3 Differentiate staphylococci from streptococci, and name several skin infections caused by each.21-4 List the causative agent, mode of transmission, and clinical symptoms of Pseudomonas dermatitis, otitis externa, acne, and Buruli ulcer.Bacterial Diseases of the SkinLearning ObjectivesCopyright © 2010 Pearson Education, Inc.Staphylococcal Skin InfectionsStaphylococcus epidermidisGram-positive cocci, coagulase-negativeStaphylococcus aureusGram-positive cocci, coagulase-positiveClinical Focus, p. 593Copyright © 2010 Pearson Education, Inc.Staphylococcus aureusAntibiotic resistantLeukocidinResists opsonizationSurvives in phagolysosomeLysozyme resistantExfoliative toxinSuperantigenClinical Focus, p. 593Copyright © 2010 Pearson Education, Inc.Staphylococcal BiofilmsFigure 21.3Copyright © 2010 Pearson Education, Inc.Staphylococcal Skin InfectionsFolliculitis: Infections of the hair folliclesSty: Folliculitis of an eyelashFuruncle: Abscess; pus surrounded by inflamed tissueCarbuncle: Inflammation of tissue under the skinImpetigo: crusting (nonbullous) sores, spread by autoinoculationCopyright © 2010 Pearson Education, Inc.Nonbullous Lesions of ImpetigoFigure 21.4Copyright © 2010 Pearson Education, Inc.Scalded Skin SyndromeToxic shock syndrome (TSS)Toxic shock syndrome toxin 1Scalded skin syndromeBullous impetigoImpetigo of the newbornCopyright © 2010 Pearson Education, Inc.Lesions of Skin SyndromeFigure 21.5Copyright © 2010 Pearson Education, Inc.Streptococcal Skin InfectionsStreptococcus pyogenesGroup A beta-hemolytic streptococciHemolysinsHyaluronidaseStretolysinsM proteinsCopyright © 2010 Pearson Education, Inc.Figure 21.6Group A Beta-Hemolytic StreptococciCopyright © 2010 Pearson Education, Inc.Streptococcal Skin InfectionsNecrotizing fasciitis ErysipelasFigure 21.7Copyright © 2010 Pearson Education, Inc.Invasive Group A Streptococcal InfectionsExotoxin A, superantigenFigure 21.8Copyright © 2010 Pearson Education, Inc.Streptococcal Toxic Shock SyndromeM proteins Complex with fibrinogen Binds to neutrophilsActivates neutrophilsRelease of damaging enzymes Shock and organ damageCopyright © 2010 Pearson Education, Inc.Infections by PseudomonadsPseudomonas aeruginosaGram-negative, aerobic rodPyocyanin produces a blue-green pusPseudomonas dermatitisOtitis externa, or “swimmer’s ear”Post-burn infectionsOpportunisticCopyright © 2010 Pearson Education, Inc.Buruli UlcerCaused by Mycobacterium ulceransDeep, damaging ulcersExceeds incidence of leprosyCopyright © 2010 Pearson Education, Inc.Classifications of AcneComedonal (mild) acne Inflammatory (moderate) acneNodular