Case StudyCase StudyPathogenic BacteriologyPathogenic Bacteriology

20092009

Case #64Case #64

Hien DangHien Dang

Note: Embedded in your PowerPoint, you must address all questions in the case!

Case SummaryCase Summary 30-year-old male exposed to chicken pox30-year-old male exposed to chicken pox

Fluid filled lesions on upper trunkFluid filled lesions on upper trunk– Chicken pox caused skin lesions that opened up the Chicken pox caused skin lesions that opened up the

following week, crusted over, and healed following week, crusted over, and healed allowed pathogen to enterallowed pathogen to enter

Septic Shock Septic Shock

Unresponsive to antibiotics, treated with Unresponsive to antibiotics, treated with vancomysin, Cardiopulmonary arrest.vancomysin, Cardiopulmonary arrest.

Death.Death.

Key Information Pointing to Key Information Pointing to DiagnosisDiagnosis

3 weeks prior to admission:3 weeks prior to admission:– Exposure to daughter infected with chicken poxExposure to daughter infected with chicken pox

Treated with acyclovirTreated with acyclovir

8 days prior to admission:8 days prior to admission:– Developed abdominal painDeveloped abdominal pain– Fluid filled lesions that opened up, crusted over, healedFluid filled lesions that opened up, crusted over, healed– Large, red Vesicle appeared on buttock Large, red Vesicle appeared on buttock

Treated with hydrocortisone creamTreated with hydrocortisone cream

1 day prior to admission:1 day prior to admission:– Shortness of breath, pain and swelling in leg, vomitingShortness of breath, pain and swelling in leg, vomiting

Admission to local hospital:Admission to local hospital:– Treated with antibioticsTreated with antibiotics– Low Respiratory rate, decreased systolic blood pressureLow Respiratory rate, decreased systolic blood pressure– Unresponsive and IntubatedUnresponsive and Intubated

The Diagnosis for Case # The Diagnosis for Case # Admission to a new hospitalAdmission to a new hospital

– Treated with Acyclovir and VancomysinTreated with Acyclovir and Vancomysin

Lab Results:Lab Results:– Liver failure, kidney failure, muscle breakdownLiver failure, kidney failure, muscle breakdown

Operating Room:Operating Room:– Gross purulence in calf towards tracking up to thighGross purulence in calf towards tracking up to thigh– Ischemic dead muscle with viable muscle tissue in thighIschemic dead muscle with viable muscle tissue in thigh

Post Surgery:Post Surgery:– Cardiopulmonary arrestCardiopulmonary arrest– Could not be resuscitatedCould not be resuscitated

Classification Gram Stain Results, and Classification Gram Stain Results, and Microscopic AppearanceMicroscopic Appearance

Family: Family: StreptococcaceaeStreptococcaceae Genus: Genus: StreptococcusStreptococcus Species: Species: pyogenes pyogenes

– Gram (+)Gram (+)– Cocci arranged in chainsCocci arranged in chains– Carbohydrate CapsuleCarbohydrate Capsule– Facultative anaerobeFacultative anaerobe

Pathogen identified as Pathogen identified as Streptococcus Streptococcus pyogenespyogenes

Streptococcus pyogenesStreptococcus pyogenes Diseases Diseases and Pathogenesisand Pathogenesis

PharyngitisPharyngitis

Wound InfectionsWound Infections

ErysipelasErysipelas

Scarlet Fever Scarlet Fever

Streptococcus pyogenes Diseases Streptococcus pyogenes Diseases and Pathogenesisand Pathogenesis

Acute glomerulonephritisAcute glomerulonephritis

Rheumatic FeverRheumatic Fever

Necrotizing fasciitisNecrotizing fasciitis

Streptococcus pyogenesStreptococcus pyogenes PathogenesisPathogenesis

Virulence factors: Virulence factors: – CapsuleCapsule

HyaluronidaseHyaluronidase

– M proteinM protein Major virulence factor, protects S. pyogenes Major virulence factor, protects S. pyogenes

from opsonization and phagocytosisfrom opsonization and phagocytosis AdherenceAdherence Superantigen, causes shock in the affected Superantigen, causes shock in the affected

patient patient – Patient experienced liver and kidney failure, Patient experienced liver and kidney failure,

fever, and Sepsis fever, and Sepsis

Streptococcus pyogenesStreptococcus pyogenes PathogenesisPathogenesis

Virulence Factors Virulence Factors – Erythrogenic ToxinsErythrogenic Toxins

Produces a toxic shock like syndrome similar to that Produces a toxic shock like syndrome similar to that caused by caused by Staphylococcus aureusStaphylococcus aureus

Superantigen:Superantigen:– Superantigen causes non-specific stimulation of T cells, Superantigen causes non-specific stimulation of T cells,

rendering the immune response useless.rendering the immune response useless.– Scarlet Fever is associated with superantigen Scarlet Fever is associated with superantigen

production.production.

– DNAseDNAse– Streptolysin S Streptolysin S – Streptolysin OStreptolysin O

Diagnosis/Isolation/Identification/ of Diagnosis/Isolation/Identification/ of Pathogen XPathogen X

Media Media – Sheep Blood Agar at 37°CSheep Blood Agar at 37°C

With Bacitracin antibiotic diskWith Bacitracin antibiotic disk

Biochemical Testing Biochemical Testing – ββ-Hemolysis-Hemolysis– Catalase (-)Catalase (-)– Oxidase (-)Oxidase (-)– SXT ResistantSXT Resistant– Taxo A Sensitive (susceptible to Bacitracin)Taxo A Sensitive (susceptible to Bacitracin)

Therapy, Prevention and PrognosisTherapy, Prevention and Prognosis

Antimicrobial Therapy:Antimicrobial Therapy:– PenicillinPenicillin– Erythromycin (if allergic to Penicillin)Erythromycin (if allergic to Penicillin)– Hydrocortisone cream is NOT effectiveHydrocortisone cream is NOT effective

Applied at red vesicle, alleviated symptoms, but did Applied at red vesicle, alleviated symptoms, but did not directly treat the bacteria, allowed it to remainnot directly treat the bacteria, allowed it to remain

Vaccine:Vaccine:– Difficult to develop, poorly immunogenic Difficult to develop, poorly immunogenic – Antibodies are protective against a specific Antibodies are protective against a specific

type of M protein type of M protein

Primary Research Article Contributing to the Primary Research Article Contributing to the Understanding of the Disease caused by Understanding of the Disease caused by

Streptococcus pyogenesStreptococcus pyogenes

O’Loughlin, RE, Roberson, A, et al. 2007. The Epidemiology of O’Loughlin, RE, Roberson, A, et al. 2007. The Epidemiology of Invasive Group A Streptococcal Infection and Potential Vaccine Invasive Group A Streptococcal Infection and Potential Vaccine Implications: United States, 2000-2004, Clinical Infectious Implications: United States, 2000-2004, Clinical Infectious Diseases 2007;45:853–862.Diseases 2007;45:853–862.

Purpose: Purpose: – To estimate the potential impact of a multivalent GAS vaccine.To estimate the potential impact of a multivalent GAS vaccine.

Methods: Methods: – Collected data from Jan 2000 to Dec 2004 via CDC at 10 US Collected data from Jan 2000 to Dec 2004 via CDC at 10 US

sites. sites. – Invasive GAS disease determined from patient with necrotizing Invasive GAS disease determined from patient with necrotizing

fasciitis or streptococcal toxic shock syndrome.fasciitis or streptococcal toxic shock syndrome.– All isolates were emm typed.All isolates were emm typed.– Used US census data to calculate rates and to make age and Used US census data to calculate rates and to make age and

race-adjusted national projections. race-adjusted national projections.

Primary Research Article Contributing to the Primary Research Article Contributing to the Understanding of the Disease caused by Understanding of the Disease caused by

Streptococcus pyogenesStreptococcus pyogenes

Results:Results:– Development of GAS vaccine is challenging because of the Development of GAS vaccine is challenging because of the

vast number of emm types (>100) vast number of emm types (>100) – Also difficult due to potential cross-reactivity between epitopes Also difficult due to potential cross-reactivity between epitopes

in the organism’s M protein and human tissuein the organism’s M protein and human tissue

Conclusion:Conclusion:– Introducing a vaccine could Introducing a vaccine could

significantly reduce morbidity significantly reduce morbidity

and mortalityand mortality

This supports my case that This supports my case that

a vaccine is difficult to develop.a vaccine is difficult to develop.

Take Home MessageTake Home Message Sepsis Sepsis Septic Shock Septic Shock Typical symptomsTypical symptoms

– Pus formationPus formation– Liver failureLiver failure– Kidney failureKidney failure

PathogenPathogen– Streptococcus pyogenesStreptococcus pyogenes

DiagnosticsDiagnostics – Antimicrobial testing involving BacitracinAntimicrobial testing involving Bacitracin– Hemolysis test (Beta-hemolytic)Hemolysis test (Beta-hemolytic)

Therapy Therapy – based on Penicillin treatment for ten days immediately following based on Penicillin treatment for ten days immediately following

infection.infection. Prevention Prevention

– Maintain proper hygiene to avoid mild superficial skin infectionsMaintain proper hygiene to avoid mild superficial skin infections– Ensure that open wounds heal properly without contact with unsanitary Ensure that open wounds heal properly without contact with unsanitary

or infectious personsor infectious persons

ReferencesReferences O’Loughlin, RE, Roberson, A, et al. 2007. The Epidemiology O’Loughlin, RE, Roberson, A, et al. 2007. The Epidemiology

of Invasive Group A Streptococcal Infection and Potential of Invasive Group A Streptococcal Infection and Potential Vaccine Implications: United States, 2000-2004, Clinical Vaccine Implications: United States, 2000-2004, Clinical Infectious Diseases 2007;45:853–862.Infectious Diseases 2007;45:853–862.

McQueen, Nancy. 2009. Streptococcus Lecture. California McQueen, Nancy. 2009. Streptococcus Lecture. California State University Los Angeles.State University Los Angeles.

Smoot, LM, McCormick JK, et al. 2002. Characterization of Smoot, LM, McCormick JK, et al. 2002. Characterization of Two novel pyrogenic toxin superantigens made by an acute Two novel pyrogenic toxin superantigens made by an acute rheumatic fever clone of Streptococcus pyogenes rheumatic fever clone of Streptococcus pyogenes associated with multiple disease outbreaks. Infection and associated with multiple disease outbreaks. Infection and Immunity, 70:7095-7104.Immunity, 70:7095-7104.

Norrby-Teglund, A, Thulin, P, et al. 2001. Evidence for Norrby-Teglund, A, Thulin, P, et al. 2001. Evidence for superantigen involvement in severe group A streptococcal superantigen involvement in severe group A streptococcal tissue infections. Jour Infec. Disease 184:853-60.tissue infections. Jour Infec. Disease 184:853-60.