Exam 1

Figures and Tables

Fig. 1.4 Pasteur’s Experiment Disproving the Theory of Spontaneous Generation p. 9

Vigorous heat is applied to producebroth free of live cells (sterile).

Intact: Microbe Growth Does Not Occur

Neck intact; airbornemicrobes are

trapped at base,and broth is sterile.

Exposed: Microbe Growth Occurs

Neck on secondsterile flaskis broken;

growth occurs.

Fig. 3.1 Structure of a Bacterial Cell

p. 63Cell (cytoplasmic) membrane—A thin sheet of lipidand protein that surrounds the cytoplasm and controls the flow of materials into and out of the cell pool.

In All Bacteria

Cytoplasm—Water-basedsolution filling the entire cell.

Ribosomes—Tiny particlescomposed of protein and RNAthat are the sites of proteinsynthesis.

Actin cytoskeleton—Long fibersof proteins that encircle the celljust inside the cell membrane andcontribute to the shape of the cell.

Bacterial chromosome or nucleoid—Composed ofcondensed DNA molecules. DNA directs all geneticsand heredity of the cell and codes for all proteins. Fimbriae—Fine, hairlike

bristles extending from thecell surface that help inadhesion to othercells and surfaces.

Cell wall—A semirigid casingthat provides structural supportand shape for the cell.

Outer membrane—Extramembrane similar to cellmembrane but alsocontaining popolysaccharide. Controls flow of materials,and portions of it are toxicto mammals when released.

In Some Bacteria

Inclusion/Granule—Stored nutrients suchas fat, phosphate, or glycogen deposited indense crystals or particles that can betapped into when needed.

Flagellum—Specialized appendage attachedto the cell by a basal body that holds a long,rotating filament. The movement pushes thecell forward and provides motility.

Pilus—An elongated, hollowappendage used in the transferof DNA to other cells.

Plasmid—Double-stranded DNA circlecontaining extra genes.

Capsule (tan coating)—A coating or layer ofmolecules external to the cell wall. It servesprotective, adhesive, and receptor functions.It may fit tightly or be very loose and diffuse.Also called slime layer and glycocalyx.

Endospore (not shown)—Dormant body formed withinsome bacteria that allows for their survival in adverse conditions.

Intracellular membranes(not shown)

In Some Bacteria (not shown)

Fig. 5.3 Generalized structure of a virus p. 119

Spike

Capsid

Nucleicacid

(a) Naked Virus (b) Enveloped Virus

Spike

Envelope

Capsid

Nucleicacid

p. 291

Fig. 11.3a 3 ways microbes damage a host p. 297

Secreted enzymes destroy tissue.

Epithelial cell

Enzymes

EnzymesBacteria

Celljunction

(a)

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Specific secreted protein binds to specific tissue target. Outer membrane component causes fever, malaise, aches, and shock.

Clostridium tetaniexotoxin travels toneurons in spinalcolumn

(b)

Exotoxins Endotoxin

Toxins

Tetanospasmin

Fig. 11.3b 3 ways microbes damage a host p. 297

Inducing Host Defenses

Inflammatory exudateCapsule of Streptococcus pneumoniae keepsit from being phagocytosed; continued bacterialpresence causes continued inflammation,especially fluid release into lungs.

(c)

Capsule

Cell

Alveoli

Pneumococci

BronchusBronchiole

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Fig. 11.3c 3 ways microbes damage a host p. 297

p. 299

Fig. 11.5 Steps involved when a microbe causes disease in a host p. 299

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Attaching Firmly

FimbriaeCapsulesSurface proteinsViral spikes

Surviving Host Defenses

Avoiding phagocytosisAvoiding death inside phagocyteAbsence of specific immunity

Causing Damage(disease)

Direct damageToxins and/orenzymes

Indirect damageInducinginappropriate,excessive hostresponse

Portals of exitRespiratory tract,salivary glandsSkin cellsFecal matterUrogenital tractBlood

SkinGI tractRespiratory tractUrogenital tractEndogenous biota

Finding a Portalof Entry

Exiting Host

Table 11.7 Carrier States p. 304

Carrier State Explanation Example

Asymptomatic carriers Infected but show no symptoms of disease

Genital herpes with no lesions

Incubating carriers Spread the infectiousagent during the incubationperiod

Infectious mononucleosis

Convalescent carriers Recuperating patients without symptoms; theycontinue to shed viable microbes and convey the infection to others

Hepatitis A

Passive carriers

Medical and dental personnel who handle patient materials that are contaminated with patient secretions and blood risk accidentally transferring them to other patients

Various healthcare-associated infections

Chronic carriers Individuals who shelter the infectious agent for along period after recovery because of the latency of the infectious agent

Tuberculosis

p. 307

Fig. 11.7 p. 308

Urinary tract40%

Surgical sites19%

Respiratory15%

Skin8%

Septicemia6%

Other (meningitis,gastroenteritis)

12%

Koch’s Postulates p. 310-311

Reisolate the same agentfrom this subject.

Inoculate a susceptible healthy subjectwith the laboratory isolate and observethe same resultant disease.

Postulate #3 Postulate #4

Table 11.10 Koch’s Postulates

Postulate #1

Find evidence ofa particular microbein every case of a disease.

Isolate that microbe from an infectedsubject and cultivate it in pureculture in the laboratory; perform fullmicroscopic and biologicalcharacterization.

Postulate #2