Group B streptococcal infection causes

Group B Streptococcal Infection Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Group B Streptococcal Infection from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Treatment
Medical Therapy
Primary Prevention
Secondary Prevention
Future or Investigational Therapies
Case Studies
Case #1
Group B streptococcal infection causes On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Group B streptococcal infection causes All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Group B streptococcal infection causes
CDC on Group B streptococcal infection causes
Group B streptococcal infection causes in the news
Blogs on Group B streptococcal infection causes
Directions to Hospitals Treating Group B streptococcal infection
Risk calculators and risk factors for Group B streptococcal infection causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Streptococcus agalactiae also known as Group B Streptococcus is a beta hemolytic gram-positive streptococcus characterized by the presence of group B Lancefield antigen. The species name "agalactiae" meaning "no milk", alludes to this. These bacteria cause Group B streptococcal infection. Streptococcus agalactiae is a species of the normal flora of the gut and female urogenital tract. Early perinatal infection causes pneumonia or septicemia, which are associated with a high mortality. During delivery, a baby can acquire S. agalactiae and develop neonatal sepsis, neonatal meningitis, and/or neonatal pneumonia. Neonates with meningitis do not present with the hallmark sign of adult meningitis, a stiff neck. They display nonspecific symptoms such as fever, vomiting, poor feeding, and irritability. The polysaccharide antiphagocytic capsule is this bacterium's main virulence factor.

S. agalactiae displays beta-hemolysis when cultured on a blood agar plate and produce zones of hemolysis that are only slightly larger than the colonies themselves. Group B streptococci hydrolyze sodium hippurate and give a positive response in the CAMP test. S. agalactiae is also sensitive to bile and will lyse in its presence.

S. galactias

Taxonomy

cellular organisms; Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae; Streptococcus

Identification

The CAMP test is an important test for identification. GBS (group B Streptococcus species) are screened through this test. It is characterized by the presence of group B Lancefield antigen and by its ability to hydrolyze sodium hippurate.

It is also sensitive to bile, and will lyse in its presence.

S. agalactiae's polysaccharide antiphagocytic capsule is its main virulence factor.

References

• Brooks, Geo F., Janet Butel, and Stephen Morse. Jawetz, Melnick, and Adelberg's Medical Microbiology, 22nd edition. 2001.
• Gillespie, Stephen and Kathleen Bamford. Medical Microbiology at a Glance. 2000.

Template:WH Template:WS