Microorganisms and Virulence Figure 27.13 Further exposure at - - PowerPoint PPT Presentation

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Mar 31, 2024 205 likes •431 views

Microorganisms and Virulence Figure 27.13 Further exposure at local sites TOXICITY: COLONIZATION toxin effects are TISSUE and local or systemic EXPOSURE INVASION ADHERENCE GROWTH DAMAGE, through epithelium to pathogens to

SLIDE 1

Microorganisms ¡and ¡Virulence ¡

SLIDE 2

Figure 27.13

EXPOSURE

to pathogens

ADHERENCE

to skin or mucosa

INVASION

through epithelium

COLONIZATION

and

GROWTH

Production of virulence factors

TOXICITY:

toxin effects are local or systemic

INVASIVENESS:

further growth at

riginal and distant sites

TISSUE DAMAGE, DISEASE

Further exposure Further exposure at local sites

SLIDE 3

Table 27.3

SLIDE 4

Figure 27.5

SLIDE 5

Figure 27.16

SLIDE 6

Figure 27.1

Microbial cells Epithelial cell Mucus

SLIDE 7

Figure 27.18

SLIDE 8

Figure 27.9 Major bacteria present Organ Esophagus Stomach Small intestine Large intestine pH 2

Secretion of acid (HCl) Digestion of macromolecules

pH 4–5

Continued digestion Absorption of monosaccharides, amino acids, fatty acids, water

pH 7

Absorption of bile acids, vitamin B12 Duodenum Jejunum Ileum Colon Anus Esophagus Lactobacilli Enterococci Prevotella Streptococcus Veillonella Helicobacter Proteobacteria Bacteroidetes Actinobacteria Fusobacteria Bacteroides Bifidobacterium Clostridium Enterobacteria Enterococcus Escherichia Eubacterium Klebsiella Lactobacillus Methanobrevibacter (Archaea) Peptococcus Peptostreptococcus Proteus Ruminococcus Staphylococcus Streptococcus

Major physiological processes

SLIDE 9

Table 27.2

SLIDE 10

Figure 27.11

Sinuses Nasopharynx Pharynx Oral cavity Larynx Trachea Bronchi Lungs

Upper respiratory tract Lower respiratory tract

SLIDE 11

Figure 27.12

Female Male

Ovary Uterus Bladder Pubis Urethra Vagina Rectum Cervix Bladder Pubis Urethra Penis Testis Rectum Prostate

SLIDE 12

Figure 27.14

Number of cells injected per mouse 101 102 103 104 105 106 107 100 80 60 40 20 Percentage of mice killed Highly virulent

rganism

(Streptococcus pneumoniae) Moderately virulent

rganism

(Salmonella enterica serovar Typhimurium)

SLIDE 13

Table 27.6

SLIDE 14

Table 27.4

SLIDE 15

Figure 27.19

SLIDE 16

Table 27.5

SLIDE 17

Figure 27.22

Excitation signals from the central nervous system Muscle

Normal

Acetylcholine (A) induces contraction of muscle fibers

Botulism

Botulinum toxin, , blocks release of A, inhibiting contraction

SLIDE 18

Figure 27.23

Inhibitory interneuron Inhibition Excitation signals from the central nervous system Tetanus toxin Muscle

Normal

Glycine (G) release from inhibitory interneurons stops acetylcholine (A) release and allows relaxation

f muscle

Tetanus

Tetanus toxin binds to inhibitory interneurons, preventing release

f glycine (G) and relaxation
f muscle

SLIDE 19

Figure 27.24

Blood Intestinal epithelial cells GM1 Lumen of small intestine

Normal ion movement, Na+ from lumen to blood, no net Cl- movement Colonization and toxin production by V. cholerae Activation of epithelial adenylate cyclase by cholera toxin Na+ movement blocked, net Cl- movement to lumen Massive water movement to the lumen; cholera symptoms

Cholera toxin AB form Vibrio cholerae cell GM1 A subunits Adenylate cyclase ATP Cyclic AMP Cholera toxin B subunit

SLIDE 20

Microbial Sidebar 27.2b

Injectosome (inv and prg products form complex) Enterotoxin (diarrhea) Endotoxin in LPS layer (fever) Anti-phagocytic proteins induced by oxyR O antigen (inhibits phagocyte killing) Siderophores Type I fimbriae (adherence) Cytotoxin (inhibits host cell protein synthesis; calcium efflux from host cell; adherence) Vi capsule antigen; inhibits complement binding Flagellum (motility) H antigen (adherence; inhibits phagocyte killing) Virulence plasmid

SLIDE 21

Figure 27.10