case study pathogenic bacteriology 2009 case #64 hien dang note: embedded in your powerpoint, you...
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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.