1. 3 er Curso Latino Americano
de Cicatrización Avanzada en
Heridas

2. 3 Comunes Invasores
Tammy Luttrell MSPT, PhD, CWS , FACCWS
Profesora Adjunto
Colorado Univerisity, Anschutz Medical Campus
National Jewish Health

3. 3 Comunes invasores
CU DPT Lecture Series Spring 2012

4. Columbia June 2012

5. Innate (First Response) Immune System
• Present from birth (Inbuilt Immunity)
• NOT Antigen specific
• No Memory--(No enhanced response with second
exposure)
• Uses cellular and humoral components
• Decreased effectiveness in the absence of Adaptive
Immunity
• Responsible for Adaptive Immune response
– Initiation
– Amplification
• Cytotoxic T Cells – CTL‟s –
• Generally Th1
Columbia June 2012

6. Basic Humoral/Adaptive Immunology
• AntiGen- Antibody Generator (Ag)
• Recognized by Antibodies (Ab)
• Immunoglobulin (IgA, IgG…)
• Made by B Lymphocytes
• T- Lymphocytes HELP B cells
• T helper cells (Th)
• Dendritic Cells (DC)
• “present” Antigen (Ag)
• Generally Th2
Columbia June 2012

7. Origin of Immune System Cells:
Innate & Adaptive
Columbia June 2012

8. WBC‟s: Who are they?
Columbia June 2012

9. General Strategies for Aversion
• Prevent Recognition
– Alter the charge associated with the outer cell membrane
(from negative to neutral)
• Cationic AMP‟s don‟t bind
– Binding to the Fc (wrong end) of IgG
• Prevents opsonization
• Complement cascade does not initiate
• Protection from HOST defenses
– Secretion of cytotoxic molecules to damage HOST
immune cells
– Secretion of enzymes that disable HOST defenses

10. 3 Virulence Factors/Strategies Used….
CU DPT Lecture Series Spring 2012

11. Streptococci
Classified into Lancefield groups (1938)
• Group A Streptococcus
S. pyogenes
– necrotising fasciitis
– toxic shock syndrome
– 1574 cases in England, Wales & NI (2010)
• Group B Streptococcus
• S. agalactiae
– Wound infections & septicaemia in adults
– 1610 cases in England, Wales & NI (2010)

12. What does group B Strep do?
• Colonisation
– Asymptomatic and intermittent
– Intestinal (<30% of adults)
– Vaginal (<25% of women)
• Infection
– Newborn babies
– Adults: the elderly, pregnant/postpartum
women, others with underlying disease

13. Group A Streptococcus (GAS)
S.pyogenes
Diseases:
•Strep Throat
•Toxic Shock
•Necrotizing Fascitis
Spring 2012
•Endocarditis
•Nephritis
A Few of the Virulence Factors:
•M protein
•Hemolysins
•Extracellular enzymes
CU DPT Lecture Series
•Gene encoding SpyCEP
Jim Henson
Mortality
10% to 15% of people with invasive GAS
25% of those with necrotizing fascitis
35% of those with toxic shock syndrome
L.A. Times:
Dividing streptococci (12,000X). Electron micrograph of Streptococcus pyogenes by Maria
Flesh-eating bacteria: Scientists identify the Fazio and Vincent A. Fischetti, Ph.D. with permission. The Laboratory of Bacterial
perpetrator Pathogenesis and Immunology, Rockefeller University.
August 13, 2008 | 4:39 pm

14. Group A Streptococcus
CU DPT Lecture Series Spring 2012

15. NETS – Neutrophil Extracellular Traps
• Unbound Chromatin (DNA)
• Histones
• Azurophilic granules
– Pore forming peptides
– Proteases
– Cytotoxic AMP‟s (Antimicrobial Peptides)
• Cytosolic proteins

16. Neutrophil “Nets”
DNA based traps for Pathogenic
Bacteria
CU DPT Lecture Series Spring 2012

17. Group A Streptococcus
Sda 1 – Breakdown of NETS
S.Pyogenes RELEASED!
Neutrophil Apoptosis
CU DPT Lecture Series Spring 2012

18. Group A Streptococcus: SLS Cytotoxcity
CU DPT Lecture Series Spring 2012

19. Facilitates penetration of S. corneum =INVASION
Spring 2012 CU DPT Lecture Series

20. Group B Strep – Virulence Factors
[Frontiers in Bioscience 9, 1794-1802, May 1, 2004]

21. Virulence Factor
GBS Surface Polysaccharide Capsule
• Antiphagocytic properties
• Capsule-deficient mutants
diminished virulence in animal
models
• Sialic acid residues on capsule
inhibit the binding of opsonically-
active C3 component of
complement to the cell surface
– blocking activation of the
alternative pathway
• Transplacental passage of type-
specific anticapsular IgG antibody
from mother to infant is an
important protective factor against
invasive disease
http://medicine.ucsd.edu/NizetLab

22. Virulence Factor
GBS β-hemolysin
• Cytotoxic to pulmonary epithelial and
endothelial cells
– Pulmonary injury and alveolar protein exudate in
early-onset pneumonia
• Activity is blocked by surfactant phospholipid
– Increased risk of premature, surfactant-deficient
neonates for severe pneumonia
• Induces cytokine release and nitric oxide
production in macrophages
– Stimulate elements of the sepsis cascade

23. S. Aureus : Pigmentation

24. Dangerous
GOLD Amblyglyphidodon
Aureus = aureus (Cuvier, 1830)
Golden damselfish
Senecio aureus “golden” Latin
Golden Groundsel
Octavian Aureus, 30 BCE
CU DPT Lecture Series Spring 2012

25. Staphlococcus „Aureus‟
Staphyloxanthin = GOLD pigment
Protects against ROS
CU DPT Lecture Series Spring 2012

26. Host
Unsuccessful
Evading
S. Aureus
Semin Immunopathol. 2012 March; 34(2): 237–259.

27. Biofilm

28. Biofilm –
What is it? And why do we care?
• Biofilm – What is it?
– Polysaccharide coating “protective covering”
for bacteria
– Self contained, micro environment for
bacterial colonies
CU DPT Lecture Series Spring 2012

29. Biofilm- Why is it a problem?
• Human phagocytes do not recognize that:
– Biofilm = Bacteria
– Biofilm goes “undetected”
• Impermeable to external Antibiotic therapy
• Bacteria are under the PS coating and
“protected”
• Rapid emergence of AB resistance to even the
very newest AB (CDC 2001)
CU DPT Lecture Series Spring 2012

30. Occurrence of Resistance
CU DPT Lecture Series Spring 2012

31. Biofilm Formation
Biofilms usually occur when one bacterial species attaches
specifically or non specifically to a surface, and then secretes
carbohydrate slime (exopolymer) that imbeds the bacteria and
attracts other microbes to the biofilm for protection or nutritional
advantages.
http://textbookofbacteriology.net/themicrobialworld/NormalFlora.html

32. Biofilm

33. So What???
• Management of wounds • Kick the BUGS OUT!!!
• Contamination versus
Disease and Infection
• Techniques supporting
HOST defense
mechanisms
• Judicious use of
antibiotics

34. Successful Host Immunity
Semin Immunopathol. 2012 March; 34(2): 237–259.

35. Macrophage Ingesting S.pyogenes
CU DPT Lecture Series Spring 2012

36. Neutrophil Ingesting S.pyogenes
CU DPT Lecture Series Spring 2012

37. Accurately Discern and Characterize Bacterial Bioburden
Spring 2012 CU DPT Lecture Series

38. Terminology: Definitions and concepts
Disease - damage caused by presence of
microorganisms or their products (can be
unapparent or without observable symptoms at a
point in time).
Colonization - presence of microorganisms without
disease at that point. This term applies to surfaces
only, i.e., the blood cannot be colonized and host
cells with intracellular infection are not colonized.
Columbia June 2012

39. Contamination vs. Infection
• All wounds are have bacteria
• Clinically infected wounds may or may not have
local and systemic changes
• What you may observe:
– Normal inflammatory response
– Mild erythema
– Cellulitis
– S/S systemic infection
Columbia June 2012

40. Basics of Wound Care
• Cleanse
• Debride
• Maintain moisture
• Assessment and Re-assessment
CU DPT Lecture Series Spring 2012

41. Cleansing of LIVING tissue
• Cautious use of:
– Antiseptics
• Providone iodine
• Sodium Hypochlorite (Dakins)
• Iodophor
• H2O2
• Acetic acid (vinegar)
CU DPT Lecture Series Spring 2012

42. Cleansing of LIVING tissue
• Create a healing environment
– Move beyond chronic inflammatory phase
• Accomplish removal of bacteria –
– IF impeding the normal progression of healing
– Do NOT eradicate bacteria at the expense of
• Fibroblasts
• Keratinocytes
• Neutrophils
CU DPT Lecture Series Spring 2012

43. Reducing Bacterial Bioburden
• Irrigation with Normal Saline
– 19 gauge needle = 4 to 15 psi pressure; 8 psi optimal
– 50+ cc of irrigant
• UVC
– Bacterial cannot replicate or mutate to UVC;
– UVC stimulates vasodilitation
– Not painful
• Ultrasound
– Facilitates liquification of slough/fibrin
– US stimulates vasodilitation
– Not painful
CU DPT Lecture Series Spring 2012

44. Wound Cleansing
• Goal
– Remove bacteria and surface contaminates
• Allow the wound to move more rapidly from
inflammation to proliferation
– Protect the healing wound
• Minimize risk of infection
– Minimize chemical and mechanical trauma
CU DPT Lecture Series Spring 2012

45. Debridement
• Mechanical
• Conservative Sharp
• Enzymatic
• Autolytic
• Surgical
• Biological - Sterile Maggots
CU DPT Lecture Series Spring 2012

46. Dressing Selection
• Thin Film
• Occlusive / Semi permeable
• Hydrocolloid
• Hydrogel
• Foam
• Alginate
• Silver
– Ionic or nanocrystalline
CU DPT Lecture Series Spring 2012

47. Dressing Selection
Based on 5 key Questions
• Is the Wound Healing
• Is the Tissue Viable or Necrotic
• Does the wound have an Optimal amount of
moisture
– (DRY CELL = DEAD CELL)
• Is there dead space
• What does the peri wound tissue look like?
CU DPT Lecture Series Spring 2012

48. Conclusions
• Bacterial Evasion Strategies
– Multiple and complex
– Antibiotic resistance- REAL and present threat
– Gene Sharing
• Share critical survival mechanisms
– Cassettes
– Phage
• Core genes
• Mobile genes (SCCmec)
• Best Defense is a good HOST OFFENSE!
– HOST immune system
• Facilitate and Support!
– Advanced Wound care

49. ¿Preguntas?
Behold the turtle. He makes progress only when he sticks his neck out.
- James B. Conant (1893-1978)