Related Experiment Video
Updated: Apr 18, 2026
10:19
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
15.3K
Vaginal group B streptococcus status during intrapartum antibiotic prophylaxis
Santiago Scasso1, Joel Laufer1, Grisel Rodriguez2
1Department of Obstetrics and Gynecology, Pereira Rossell Hospital, University of Uruguay, Montevideo, Uruguay.
Summary
Four hours of intrapartum antibiotic prophylaxis (IAP) with penicillin G is necessary to significantly reduce maternal group B streptococcus (GBS) colonization. This duration ensures effective treatment and optimal pharmacokinetic profiles in cord blood and amniotic fluid.
Area of Science:
- Obstetrics and Gynecology
- Infectious Diseases
- Pharmacokinetics
Background:
- Group B Streptococcus (GBS) is a leading cause of neonatal infections.
- Intrapartum antibiotic prophylaxis (IAP) is crucial for preventing vertical GBS transmission.
- Understanding the optimal duration and pharmacokinetic profile of IAP is essential for effective GBS prevention.
Purpose of the Study:
- To evaluate maternal GBS colonization status during intrapartum antibiotic prophylaxis (IAP).
- To determine the pharmacokinetic profile of penicillin G in umbilical cord blood and amniotic fluid.
- To assess the effectiveness of 4-hour IAP in reducing GBS colonization.
Main Methods:
- Prospective study involving 60 GBS-colonized pregnant women in active labor.
- Administration of intravenous penicillin G according to a standard regimen.
- Collection of rectovaginal, cord blood, and amniotic fluid samples at specified intervals for GBS culture and penicillin G concentration analysis via high-performance liquid chromatography.
Main Results:
- 72% of women were GBS carriers before IAP initiation.
- After 4 hours of IAP, GBS colonization was reduced to 12% (from 53% at 2 hours).
- Penicillin G concentrations in cord blood and amniotic fluid remained above the minimum inhibitory concentration (0.12 μg/mL) throughout the study period.
Conclusions:
- A 4-hour duration of intrapartum antibiotic prophylaxis (IAP) is required to achieve a significant reduction in GBS colonization.
- The pharmacokinetic profile of penicillin G supports its efficacy during a 4-hour IAP regimen.
- Optimizing IAP duration is critical for enhancing its effectiveness in preventing GBS-related neonatal infections.
Related Concept Videos
01:28Development of the Oral Microbiota
46
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
46
01:25Clinical Significance of Antibiotic Resistance
61
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within...
61
01:30Development of Human Microbiota
50
The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from...
50
01:28Microbiota of the Urogenital Tract
49
The human urogenital system, once thought to be sterile in healthy individuals, is now recognized as a complex microbial habitat. Advancements in molecular sequencing techniques have revealed that even in healthy adults, the kidneys and bladder harbor microbial populations similar to those found in the distal urethra, albeit in much lower abundance. These resident microorganisms, while generally innocuous, can become opportunistic pathogens under conditions that alter the urogenital...
49
01:28Acute Pyelonephritis II: Diagnostic Studies and Management
750
Introduction:For diagnosing acute pyelonephritis, a comprehensive patient history is collected to identify symptoms such as dysuria, frequent or urgent urination, flank pain, or costovertebral angle (CVA) tenderness that may suggest a kidney infection.Physical ExaminationDuring the physical examination, CVA tenderness is assessed. This involves gentle percussion over the costovertebral angle, where tenderness often indicates a kidney infection.Diagnostic TestsUrinalysis: Used to identify white...
750
01:22Bacterial Meningitis I: Introduction
3
Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...
3