Group B Streptococcus, also known as GBS, is a type of bacteria that can cause serious infections in pregnant women and newborn babies. It’s estimated that around 25% of pregnant women carry GBS in their vaginal or rectal area, making it a common bacteria that is often harmless. However, when GBS is transmitted from a mother to her baby during delivery, it can cause serious health complications, including sepsis, pneumonia, and meningitis.
The good news is that GBS infections can be prevented by administering antibiotics during labor to mothers who test positive for GBS. However, the effectiveness of antibiotics in treating GBS infections is now under question due to rising antibiotic resistance.
Antibiotic resistance occurs when bacteria develop the ability to resist the effects of antibiotics, making them more resistant to medical treatment. This type of resistance occurs naturally over time, but it has been accelerated by the overuse and misuse of antibiotics. As bacteria become more resistant to antibiotics, new, stronger antibiotics must be developed to treat them.
The CDC has warned that GBS and other bacteria are becoming increasingly resistant to antibiotics, posing a serious threat to public health. A study published in the journal Antimicrobial Agents and Chemotherapy found that 20% of GBS bacteria isolated in the US were resistant to clindamycin, a commonly used antibiotic.
Resistance to Antibiotics in GBS
GBS resistance to antibiotics is a growing problem, with studies showing varying degrees of resistance to different antibiotics used for GBS infection treatment. A study published in the Journal of Antimicrobial Chemotherapy found that GBS resistance to erythromycin and clindamycin had increased by around 30% between 1996 and 2006.
A 2018 study published in the medical journal Infection and Drug Resistance found that the most common resistance mechanism seen in GBS was the presence of the ermB gene. This gene produces an enzyme that can modify the antibiotic, rendering it ineffective. Other resistance mechanisms found in GBS included the presence of the mefA and msrD genes, which have a similar mode of action.
Although antibiotic resistance in GBS hasn’t yet reached epidemic proportions, the emergence of resistant strains is concerning, especially given the potential consequences of GBS infection in newborns.
Treating GBS Infections
Currently, the main treatment for GBS infections in newborns is intravenous administration of antibiotics, usually penicillin or ampicillin. Antibiotic treatment must be started as soon as possible after the onset of symptoms, ideally within the first hour.
Antibiotic resistance can affect the effectiveness of treatment, leading to longer hospital stays, increased morbidity, and higher mortality rates. Therefore, prompt diagnosis and treatment with an appropriate antibiotic is crucial to minimize these risks.
Preventing GBS Infections
Prevention is key when it comes to GBS infections, and the most effective way to prevent transmission of the bacteria from mother to child is through intrapartum antibiotic prophylaxis (IAP). IAP involves administering antibiotics to mothers who test positive for GBS during their pregnancy, usually starting at 36-37 weeks gestation.
The standard antibiotic used for IAP is penicillin, but if the mother is allergic, other antibiotics such as clindamycin, erythromycin, or vancomycin can be used. However, with the rising prevalence of antibiotic resistance in GBS, it’s becoming increasingly important to monitor the effectiveness of these antibiotics and to consider alternative treatment options if necessary.
One alternative treatment that has been increasingly studied for GBS infection prevention is the use of probiotics. Probiotics are live microbes that are believed to promote health in the host by adjusting the balance of microorganisms in the gut microbiome.
Several studies have investigated the use of probiotics for preventing GBS colonization in pregnant women, with varying results. A study published in the journal PLoS One found that administration of Lactobacillus plantarum to women in late pregnancy significantly reduced vaginal colonization with GBS. Similarly, a study published in the Journal of Maternal-Fetal and Neonatal Medicine found that oral administration of Lactobacillus rhamnosus GG reduced the incidence of GBS colonization in pregnant women.
While these studies show promise for the use of probiotics as an alternative treatment for preventing GBS infection, more research is needed to confirm their efficacy.
Group B Streptococcus is a common bacteria that is usually harmless in adults, but can cause serious infections in newborns. The effectiveness of antibiotics in treating GBS infections is now under question due to rising antibiotic resistance, making it increasingly important to monitor antibiotic effectiveness and to consider alternative treatment options.
Prevention through intrapartum antibiotic prophylaxis is currently the most effective way to prevent GBS transmission to newborns. However, as antibiotic resistance continues to rise, alternative treatments such as probiotics may become more important in preventing and treating GBS infections.