Streptococcal Serology Terry Kotrla

Introduction Gram-positive Beta hemolytic Spherical, ovoid or lancet shaped Pairs or chains

Divided into Serotypes or groups Two major outer proteins M and T Eighteen interior proteins knows as Lancefield grouping Streptococcus pyogenes belong to Lancefield group A M protein chief virulent factor

Numerous Exoantigens Exoantigens are produced and excreted and include: Streptolysin O Dnase Hyaluronidase Nicotinamide Adenine Dinucleotidase Streptokinase Patients react to exoantigens by producing antibodies

Characteristics Two major sites of infection Upper respiratory tract Skin If infections left untreated can lead to post-streptococcal sequelae Acute glomerulonephritis Rheumatic fever

Upper Respiratory Sore Throat Tonsillar exudate Fever Chills 20% school children carriers

Skin Impetigo Lesions on extremities Commonly on face Pustular and crusty

Suppurative Complications Suppurate -To generate pus; as, a boil or abscess suppurates. Erysipelas Necrotizing fasciitis Scarlet fever

Erysipelas Infection involves the dermis and lymphatics and is a more superficial subcutaneous infection of the skin than cellulitis. characterized by intense erythema, induration and a sharply demarcated border.

Necrotizing Fasciitis

Scarlet Fever Strep bacteria produces a toxin that causes a rash Sandpapery Peels

Non-Suppurative Inflammatory response elsewhere in the body. Damaging sequelae to strep infection Rheumatic Fever Post-Streptococcal glomerulonephritis

Rheumatic Fever Delayed consequence of an untreated upper respiratory infection with group A streptococci Causes serious, debilitating damage to the heart. Associated with large amount of M protein and a capsule Due to immune response against Strep antigens similar to heart antigens.

Rheumatic Fever This is the heart of a 44 year old woman who had rheumatic fever and had been treated for congestive heart failure for about one year.

Poststreptococcal glomerulonephritis Follows strep infection of skin or pharynx Characterized by damage to glomeruli of kidneys Deposition of Ag-Ab complexes, activation of complement. Inflammatory response causes damage.

Poststreptococcal glomerulonephritis Most common in children 2-12 Symptoms: Hematuria Proteinuria Edema hypertension

Poststreptococcal glomerulonephritis The scattered capillary wall granular deposits in acute poststreptococcal glomerulonephritis also stain for complement (immunofluorescence with antibody to C3)

Laboratory Testing Culture and identification Rapid Strep Tests from throat swab Detection of Streptococcal antibodies Anti-Streptolysin O (ASO) titer