streptococci & enterococci david a. wininger, md internal medicine residency program director...
TRANSCRIPT
![Page 1: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/1.jpg)
Streptococci & Enterococci
David A. Wininger, MDInternal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division of Infectious DiseasesThe Ohio State University Wexner Medical Center614-293-3989 [email protected]
![Page 2: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/2.jpg)
Learning Objectives
Recognize the structure and microbial physiology of Streptococci and Enterococci and integrate this information with the human pathophysiologic correlates Define the structure and composition of Streptcocci and Enterococci
Recognize the underlying genetic mechanisms of antibacterial resistance in Streptococci and Enterococci
Describe the nature and mechanisms of action of Streptococcal and Enterococcal virulence factors
Identify the normal human immune response to Streptococcal and Enterococcal infections
![Page 3: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/3.jpg)
Learning Objectives
Recognize the epidemiology and ecology of Streptococcal and Enterococcal infections
Describe and differentiate the principles of laboratory diagnosis for Streptococcal and Enterococcal infections
Define the principles of infection prevention for Streptococcal and Enterococcal infections
Recognize treatment options and accurately evaluate their role in the therapy of infections due to Streptococci and Enterococci
![Page 4: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/4.jpg)
Streptococci
Catalase negative
Gram Stain
![Page 5: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/5.jpg)
Classification of Streptococci
Hemolytic pattern Alpha
Beta
Gamma
(On sheep blood agar)
Lancefield Groups: Cell wall carbohydrates by serologic tests Groups A-H, K-M, O-V
Biochemical properties – see discussion by species
Downloaded from: Principles and Practice of Infectious Diseases (on 17 January 2005 06:10 PM)
![Page 6: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/6.jpg)
Downloaded from: Principles and Practice of Infectious Diseases (on 17 January 2005 06:10 PM) © 2004 Elsevier
Group A Streptococci (S. pyogenes)
Sheep Blood Agar Plate
Beta hemolysis
Bacitracin inhibits growth
PYR positive
![Page 7: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/7.jpg)
Group A Streptococci – Structure & Virulence Factors
• M-protein
• Lipoteichoic acid
• F-protein
• Capsule
![Page 8: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/8.jpg)
Group A Streptococci – Virulence Factors
Toxins Pyrogenic exotoxins (SpeA, SpeB, SpeC, SpeF)
Super-antigens
Streptococcal Toxic Shock Syndrome, Scarlet Fever
Enzymes Streptolysin S Lyses red blood cells
Streptolysin O Basis of ASO test
Streptokinases Lyses clots
DNases Thins out pus
C5a peptidase Block chemotaxis
![Page 9: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/9.jpg)
Group A Streptococci – Clinical Syndromes
Acute Streptococcal Pharyngitis (“Strep Throat”)
![Page 10: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/10.jpg)
Group A Streptococci – Clinical Syndromes
Strawberry Tongue Desquamation(recovery phase)
Scarlet Fever(Group A Strep strains producing SPE)
![Page 11: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/11.jpg)
Group A Streptococci – Clinical Syndromes
Impetigo Erysipelas Cellulitis
CDC/Dr. Thomas F. Sellers/Emory University
![Page 12: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/12.jpg)
Group A Streptococci – Clinical Syndromes
Valvulitis (Mitral valve)
Erythema marginatum
Rheumatic Fever & Rheumatic Carditis(Non-suppurative, post-streptococcal)
![Page 13: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/13.jpg)
Group A Streptococci – Clinical SyndromesAcute Post-Streptococcal
Glomerulonephritis (APSGN)
![Page 14: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/14.jpg)
Post-Streptococcal Non-Suppurative Complications
Rheumatic Fever Mostly strep throat M-types
Acute Post-Streptococcal Glomerulonephritis (APSGN) Some after dermal infection
Rationale for finishing full antibiotic course Penicillin G works in preventing Rheumatic Fever, BUT NOT
APSGN
![Page 15: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/15.jpg)
Group B Streptococci (S. agalactiae)
Laboratory Diagnosis: Culture shows a Beta-hemolytic Streptococci expressing “Group B” cell wall carbohydrate. Requires enriched media for optimal growth.
Main Virulence factor: Capsule that prevents phagocytosis
Epidemiology and Ecology: GI & GU tract colonization
Vulnerable populations: Neonates, colonized women post-partum, older patients with cancer or diabetes
Treatment: Easily treated with penicillins (i.e. Penicillin G, Ampicillin)
Cephalosporins or Vancomycin for penicillin-allergic patients
![Page 16: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/16.jpg)
Group B Streptococci – Clinical Syndromes
Clinical Disease in Peri-partum Period Neonatal sepsis (early and late)
Neonatal meningitis
Post-partum sepsis
Prevention of Peri-partum Infections Pre-partum vaginal screening cultures
Carriers receive antibiotics in labor
Prophylaxis has reduced neonatal sepsis rates
No vaccine is available
![Page 17: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/17.jpg)
Group B Streptococci – Clinical Syndromes
Non-pregnant Adults Urinary tract infections
Bacteremia and sepsis
Soft tissue infections
Musculoskeletal infections
Mainly in patients compromised by: Age
Diabetes mellitus
Cancer
![Page 18: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/18.jpg)
Downloaded from: Principles and Practice of Infectious Diseases (on 17 January 2005 06:09 PM) © 2004 Elsevier
Streptococcus pneumoniae
Gram Stain Laboratory Diagnosis
Gram (+) diplococci “Lancet shaped” Alpha-hemolytic Fastidious nutritional req. Susceptible to optochin Bile soluble
![Page 19: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/19.jpg)
Downloaded from: Principles and Practice of Infectious Diseases (on 17 January 2005 06:11 PM) © 2004 Elsevier
S. pneumoniae – Structure & Virulence Factors
Capsule Key virulence factor Anti-phagocytic For sero-typing Basis for vaccination Rough strains (avirulent)
Other Virulence Factors Surface adhesins Pneumolysin (cytotoxin) sIgA Protease Teichoic Acid H2O2
![Page 20: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/20.jpg)
Downloaded from: Principles and Practice of Infectious Diseases (on 17 January 2005 06:09 PM) © 2004 Elsevier
S. pneumoniae – Clinical Syndromes
Pneumococcal Pneumonia
![Page 21: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/21.jpg)
S. pneumoniae – Clinical SyndromesLung Tissue
Acute Left Maxillary Sinusitis
No Pneumonia Acute Pneumococcal Pneumonia
![Page 22: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/22.jpg)
S. pneumoniae – Clinical Syndromes
Other associated infections Acute Otitis Media
Acute Bacterial Meningitis
Bacteremia (with pneumonia or meningitis)
Pneumococcal sepsis
CDC
![Page 23: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/23.jpg)
S. pneumoniae – Treatment & Antibacterial Resistance Historically highly susceptible to penicillins
Increasing rates of penicillin resistance due to altered penicillin binding proteins (PBPs). Serious disease Need susceptibilities to rule out penicillin resistance
Primary empiric treatment usually consists of a 3rd Generation Cephalosporin (i.e. Ceftriaxone, Cefotaxime)
Alternative treatments include: Vancomycin
“Respiratory” (anti-pneumococcal) Fluroquinolones (i.e. Moxifloxacin, Levofloxacin)
![Page 24: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/24.jpg)
S. Pneumoniae – Normal Human Immune Response & Prevention
Humoral immunity is key
Anticapsular antibodies are protective Basis for vaccination
Asplenics are at increased risk for serious sepsis!!!
Vaccinate patients prior to elective splenectomy
23-valent vs. 13-valent conjugate vaccine
Acute inflammatory response during disease Neutrophils
![Page 25: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/25.jpg)
Viridans Streptococci
A heterogeneous group (not a single species) Often alpha hemolytic (“Viridis” – Green)
S. mitior, S. mutans, and numerous others
S. bovis bloodstream infections occult colon cancer!!
Laboratory Diagnosis Culture “Viridans”- grouping is often enough
Speciation Biochemicals and Mass Spectroscopy
Epidemiology/Ecology Normal flora or colonizers of oral, GI and GU tracts
![Page 26: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/26.jpg)
Viridans streptococci
Clinical Syndromes Endocarditis, bacteremia, dental abscess and intra-abdominal abscess.
(No noteworthy virulence factors)
Normal Human Immune Response/Prevention Ubiquitous organisms that take advantage of breaks in normal mucosal
surfaces, triumphing due to sheer numbers and structural defects of the host (bad teeth, abnormal heart valves, prosthetic materials) but can be cleared with acute inflammation (neutrophils)
Treatment Often penicillin susceptible, but resistance happens; can add
aminoglycoside (for synergy) or use vancomycin while awaiting MIC’s.
![Page 27: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/27.jpg)
Enterococci E. faecalis and E. faecium
Most common pathogenic species
Laboratory Diagnosis Group D “strep”
Usually alpha hemolytic (can vary!)
Hardy: grows in wide temp range, pH range, salt concentrations, bile salts, aerobic and anaerobic conditions
PYR positive
Catalase negative
Gram Stain
![Page 28: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/28.jpg)
Enterococci
Ecology and Epidemiology Fecal flora (GI tract) and can colonize GU tract Overgrow when antibiotics eliminate other endogenous flora Spreads patient to patient
Virulence Factors Adherence and biofilm formation (pili, surface proteins, etc.)
Clinical Syndromes Urinary Tract Infections Bacterial endocarditis and other bacteremias Abdominal wounds and intra-abdominal infections
![Page 29: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/29.jpg)
Enterococci – Antibacterial Resistance & Treatment
Inherent resistance to some classes (i.e. cephalosporins)
Intrinsic decreased susceptibility to others (i.e. penicillins)
Multidrug resistance, including to Vancomycin (VRE)
Most commonly seen in E. faecium strains
Treatment depends on susceptibility
Penicillin G or Ampicillin
Vancomycin
Synergy with aminoglycosides (i.e. Gentamicin, Streptomycin)
![Page 30: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/30.jpg)
VRE – Mechanism of Resistance
![Page 31: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/31.jpg)
Vancomycin Resistant Enterococci (VRE)
Antimicrobial Treatment Options Linezolid Daptomycin Tigecycline Quinupristin/Dalfopristin
Infection Control Precautions Minimize antibiotic “pressure” Contact isolation precautions
![Page 32: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/32.jpg)
Summary – Streptococci & Enterococci
Gram positive cocci in pairs or chains
Targeted sites of infection depending on the species
Pathogenesis merger of the sites of initial contact or colonization and the virulence features of the species
Diagnosis based on Gram stain morphology, hemolysis pattern on Sheep Blood Agar and presence or absence of characteristic cell wall carbohydrates
Penicillin optimal treatment for a subset of the strep species
Enterococci Restricted antimicrobial treatment options
![Page 33: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/33.jpg)
Streptococci and Enterococci Quiz
![Page 34: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/34.jpg)
Thank you for completing this module
• If you have any questions, write to me at [email protected]
• Phone messages can be left at 614-293-3989.
David Wininger, MD
![Page 35: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/35.jpg)
References
Medical Microbiology, 7th Ed. Murray, Rosenthal & Pfaller; Chapter 19, pages 188-204; Chapter 20, pages 205-208.
![Page 36: Streptococci & Enterococci David A. Wininger, MD Internal Medicine Residency Program Director Associate Professor, Clinical Internal Medicine Division](https://reader036.vdocuments.mx/reader036/viewer/2022062308/56649db25503460f94aa1205/html5/thumbnails/36.jpg)
Survey
We would appreciate your feedback on this module. Click on the button below to complete a brief survey. Your responses and comments will be shared with the module’s author, the LSI EdTech team, and LSI curriculum leaders. We will use your feedback to improve future versions of the module.
The survey is both optional and anonymous and should take less than 5 minutes to complete.
Survey