Duration of intrapartum antibiotics for group B streptococcus on the diagnosis of clinical neonatal sepsis

How can we reduce neonatal sepsis after universal group B streptococcus screening?

BACKGROUND

Group B Streptococcus (GBS) infection remains a leading cause of newborn morbidity and mortality. The study aimed to determine the adherence rate to the universal screening policy a decade after its introduction. Secondly, whether the timing of antibiotics given in GBS carriers reduces the incidence of neonatal sepsis.

METHODS

Delivery records at Hong Kong Baptist Hospital in 2022 were examined to retrieve antenatal and intrapartum details regarding maternal GBS carrier status, previous maternal GBS carrier status, antibiotic treatment, timing of treatment, neonatal condition at birth and whether the neonate had sepsis. Univariate statistics was used to assess the relationship between maternal GBS carrier and neonatal sepsis overall. Incidence of neonatal sepsis was stratified according to mode of delivery and timing of antibiotic.

RESULTS

The adherence rate to the universal GBS screening policy was 97%. The risk of neonatal sepsis was 5.45 (95% CI 3.05 to 9.75) times higher in women who were GBS screened positive when compared to non-GBS carriers (p < 0.001). Amongst term neonates from GBS carriers delivered by Caesarean section, the risk of neonatal sepsis significantly decreased by 70% after antenatal antibiotic treatment (p = 0.041) whereas in term neonates delivered vaginally, the risk of neonatal sepsis decreased by 71% (p = 0.022) if intrapartum antibiotic prophylaxis was given 4 or more hours.

CONCLUSION

Giving antenatal antibiotic treatment before Caesarean section or intrapartum antibiotic prophylaxis for 4 or more hours before vaginal delivery may decrease the risk of neonatal sepsis in term neonates delivered from GBS carriers.

Group B Streptococcus and Intraamniotic Inflammation and Infection

Intraamniotic inflammation and infection complicate 2% to 5% of term deliveries. Group B Streptococcus (GBS) is a common cause of intraamniotic infection associated with invasive neonatal disease and maternal morbidity. Universal vaginal-rectal screening for GBS colonization is recommended between 36 and 37 weeks. Intrapartum antibiotic prophylaxis is recommended for individuals with positive GBS screens and other risk factors. Intravenous penicillin is the preferred antimicrobial agent. Individuals with penicillin allergies may receive cefazolin for low-risk allergies and either clindamycin or vancomycin for high-risk allergies, depending on their antimicrobial susceptibilities. Clinical trials are underway to evaluate the safety and immunogenicity of maternal anti-GBS vaccine candidates.

Timing and dosage of intrapartum prophylactic penicillin for preventing early-onset group B streptococcal disease: assessing maternal and umbilical cord blood concentration

OBJECTIVE

Timing of administration of antibiotics and concentrations in maternal blood and the umbilical cord blood are important prerequisites for optimal intrapartum antibiotic prophylaxis (IAP) of neonatal early-onset group B streptococcus (GBS) disease. This cohort study aimed to explore penicillin concentrations in mothers and infants at birth in relation to time elapsed from administration to delivery and to the minimal inhibitory concentration (MIC) for GBS.

MAIN OUTCOME MEASURES

Penicillin G concentrations in maternal and umbilical cord blood in relation to time and dose from administration to time of delivery.

RESULTS

In 44 mother-infant dyads, median maternal penicillin G concentration was 0.2 mg/L (IQR 0-0.8 mg/L; range 0-1.6 mg/L). Median infant penicillin G concentration was 1.2 mg/L (IQR 0.5-5.0 mg/L; range 0-12.7 mg/L). In all infants (N=38) born less than 4 hours after the latest IAP administration, penicillin G concentrations far exceeded MIC (0.125 mg/L), even after short time intervals between IAP administration and birth. The highest plasma concentrations were reached in umbilical cord blood within 1 hour from IAP administration to birth.For 44 mother-infant dyads, maternal concentrations were very low compared with their infants'; particularly, very high concentrations were seen in the 20 infants with only one dose of IAP.

CONCLUSION

High concentrations of penicillin G were found in umbilical cord blood of infants born less than 4 hours after IAP administration, well above the MIC for GBS.

Group B Streptococcus and the risk of perinatal morbidity and mortality following term labor

Streptococcus agalactiae (group B Streptococcus) colonizes the genital tract of approximately 20% of pregnant women. In the absence of intervention, approximately 1% of infants born to colonized mothers exhibit a clinical infection. This has led to implementation of screening and intervention in the form of intrapartum antibiotic prophylaxis in many countries, including the United States. However, screening has not been introduced in a substantial minority of other countries because of the absence of supportive level 1 evidence, the very large number needed to treat to prevent 1 case, and concerns about antimicrobial resistance. Optimal screening would involve rapid turnaround (to facilitate intrapartum testing) and report antibiotic sensitivity, but no such method exists. There is significant scope for a personalized medicine approach, targeting intrapartum antibiotic prophylaxis to cases at greatest risk, but the pathogen and host factors determining the risk of invasive disease are incompletely understood. Epidemiologic data have indicated the potential of prelabor invasion of the uterus by group B Streptococcus, and metagenomic analysis revealed the presence of group B Streptococcus in the placenta in approximately 5% of pregnant women at term before onset of labor and membrane rupture. However, the determinants and consequences of prelabor invasion of the uterus by group B Streptococcus remain to be established. The vast majority (98%) of invasive neonatal disease is caused by 6 serotypes, and hexavalent vaccines against these serotypes have completed phase 2 trials. However, an obstacle to phase 3 studies is conducting an adequately powered trial to demonstrate clinical effectiveness given that early-onset disease affects approximately 1 in 1000 births in the absence of vaccination.

Group B Streptococcus in Pregnancy

To decrease risk of early-onset neonatal sepsis from group B streptococcus (GBS), pregnant patients should undergo screening between 36 0/7 and 37 6/7 weeks' gestation. Patients with a positive vaginal-rectal culture, GBS bacteriuria , or history of newborn with GBS disease should receive intrapartum antibiotic prophylaxis (IAP) with an agent targeting GBS. If GBS status is unknown at time of labor, IAP should be administered in cases of preterm birth, rupture of membranes for >18 hours, or intrapartum fever. The antibiotic of choice is intravenous penicillin; alternatives should be considered in cases of penicillin allergy depending on allergy severity.

What's new in the management of neonatal early-onset sepsis?

The expert guidelines highlighted in this review provide an evidence-based framework for approaching at-risk infants and allow for a more limited and standardised approach to antibiotic use. While these guidelines have significantly reduced antibiotic utilisation worldwide, optimally each unit would individualise their approach to early onset sepsis (EOS) based on the neonatal population they serve and available resources. As advancements in EOS research continue and limitations with sepsis prediction tools are addressed, it is inevitable that our risk stratification and management guidelines will become more precise.

Maternal Origins of Neonatal Infections: What Do Obstetrician-Gynecologist Should/Could Do?

Neonatal infections are responsible for 20% of neonatal deaths yearly. In this review, we focused on the origins of the commoner neonatal infections, and we define the role of obstetricians. Regarding group B Streptococcus, a key measure for the prevention of neonatal infection is the vaginal-rectal culture screening at term pregnancy. Intravenous penicillin is the first-line prophylaxis at the start of labor, with intravenous ampicillin as an alternative. First-generation cephalosporins or clindamycin are recommended in case of penicillin allergy. Concerning urinary tract infections (UTIs), guidelines recommend complete urinalysis and urine culture in the first trimester of pregnancy for the screening of asymptomatic bacteriuria. For lower UTIs, guidelines recommend nitrofurantoin as first-choice antibiotic. Amoxicillin or cefalexin are second-line antibiotics. For upper UTIs, guidelines recommend cephalexin per os as first line. Candida spp. colonization affects 20% of pregnant women; however, congenital fetal candidosis and Candida amnionitis are rare. First-line treatment in case of symptomatic vaginitis during pregnancy or asymptomatic colonization during the third trimester is vaginal clotrimazole. Fluconazole is not approved in pregnancy, especially during the first trimester. Genital mycoplasmas colonization during pregnancy is usually asymptomatic and associated with bacterial vaginosis. Colonization is related to neonatal respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), pneumonia, chorioamnionitis, and sepsis. Macrolides are the first-line treatment along with lactobacillus supplementation. In cases of preterm premature rupture of membranes or preterm labor, ceftriaxone, clarithromycin, and metronidazole are required to prevent intra-amniotic infection. Intra-amniotic infection affects 1 to 5% of deliveries at term and one-third of preterm ones and is associated with perinatal death, early-onset neonatal sepsis, RDS, BPD, pneumonia, meningitis, and prematurity-related diseases. Guidelines recommend a combination of ampicillin and gentamicin, and in case of caesarean section, an additional dose of clindamycin or metronidazole is required. In conclusion, obstetricians should be aware that the treatment of maternal infection during pregnancy can prevent potentially lethal infections in the newborn. KEY POINTS: · Part of neonatal infections starts from maternal infections that must be treated during pregnancy.. · Streptococcus group B and asymptomatic bacteriuria should be investigated in pregnancy and treated.. · Mycoplasma and ureaplasma vaginal colonization during pregnancy is related to negative neonatal outcomes..

Maternal Group B Streptococcal Rectovaginal Colonization after Intrapartum Antibiotic Prophylaxis

Maternal rectovaginal colonization with Group B Streptococcus (GBS) during labor is a prerequisite for neonatal early-onset GBS disease. Intrapartum antibiotic prophylaxis (IAP) has been proven to prevent GBS perinatal infection, while there are few studies on the evaluation of the effectiveness of different antibiotic prophylaxis regimens. This study aimed to assess the maternal rectovaginal GBS colonization status after IAP, antimicrobial susceptibility and maternal and neonatal outcomes among women administered different antibiotic prophylaxis regimens. A prospective study was conducted between June 2018 and June 2022. GBS carriers identified at 35-37 weeks of gestation were provided IAP (penicillin, cefazolin or clindamycin) at delivery based on the local protocol for GBS prevention. Rectovaginal samples were obtained from participants again after delivery. Antimicrobial susceptibility testing in GBS isolates was performed using the broth microdilution method. A total of 295 cases were included in this study. In the postpartum re-examination for GBS, the overall negative rectovaginal culture rate was 90.8% (268/295). Women who received cefazolin prophylaxis had the highest negative culture rate (95.2%, 197/207), which was followed by those who received penicillin (80.7%, 67/83) and clindamycin (80.0%, 4/5) (p = 0.001). All GBS isolates achieved sensitivity to penicillin and cefazolin, whereas resistance to clindamycin was shown in 21.4% of the strains. There were no significant differences in maternal and neonatal outcomes among the IAP groups. The use of IAP is highly effective in reducing the maternal rectovaginal GBS colonization. Cefazolin may offer equivalent efficacy and safety compared to standard penicillin prophylaxis.

Antibiotic treatments to mothers during the perinatal period leaving hidden trouble on infants

Antibiotic application during the perinatal period is unavoidable in the clinic, but the potential effects on mothers and infants remain unknown. Herein, 25 breast milk samples from mothers who received cefuroxime (CXM) or CXM + cefoxitin (CFX) treatments and fecal samples from their infants were collected to investigate the undesirable effects of antibiotics on the microbiota of mothers and neonates. Furthermore, five fecal samples of infants, whose mothers had antibiotic treatments, were collected at a 6-month postpartum follow-up visit to evaluate the long-term effects on infants' gut microbiota. Moreover, the relative abundance of antibiotic resistance genes (ARGs) in fecal samples was compared to investigate the transfer of ARGs in the infant gut microbiota. The results indicated that the antibiotic treatments had no influence on the microbiota of breast milk. The dominant bacterial phyla in the fecal samples changed to Firmicutes and Proteobacteria after antibiotic treatments, while the bacterial community showed a recuperative trend at the follow-up visits. In addition, the abundance of ARGs in the infant gut microbiota demonstrated a declining trend in the CXM- and CXM + CFX-treated groups, while ARG abundance presented a significant increasing trend after a 6-month recovery period.

CONCLUSION

Antibiotic treatments for mothers during the perinatal period disturb the gut microbiota in neonates. The infants' gut microbiota would partly return to their initial state after rehabilitation, but the transfer of ARGs would leave the hidden trouble of antibiotic resistance. Overall, the data presented here can help to guide the scientific use of antibiotics during the perinatal period and provide potential approaches to mitigate the negative consequences.

WHAT IS KNOWN

• Antibiotic application during the perinatal period is unavoidable in the clinic. • Misuse of antibiotics can cause various unintended consequences, especially for antibiotic resistance.

WHAT IS NEW

• Antibiotic treatments had no influence on the microbiota of breast milk but greatly disturbed the gut microbiota composition in infants. • The gut microbiota in infants would partly return to its initial state after rehabilitation but the transfer of ARGs would leave the hidden trouble of antibiotic resistance.

Updates in prevention policies of early-onset group B streptococcal infection in newborns

Invasive disease owing to group B Streptococcus (GBS) is a major cause of illness and death among newborns. Maternal GBS colonization of gastrointestinal tract and/or vagina is the primary risk factor for neonatal GBS early-onset disease (EOD). In Europe and America, there are marked declines in neonatal GBS-EOD through widespread implementation of guidelines for maternal GBS screening and subsequent intrapartum antibiotic prophylaxis (IAP). The key measures necessary for prevention of GBS-EOD include correct specimen collection and processing, nucleic acid amplification testing (NAAT) for GBS identification, regimens for mothers with premature rupture of membranes (PROM), preterm labor or penicillin allergy, and coordination between obstetrics and pediatrics. Antibiotic prophylaxis has some disadvantages, so researchers should develop other preventive measures. Maternal vaccines to prevent perinatal GBS infection are currently under development. However, as large, population-based sampling studies are rarely conducted, the colonization rate and the disease burden of GBS in perinatal period are poorly understood in developing countries. The harm of GBS to newborns has been recognized in recent years in mainland China, but authorized prevention measures are still lacking. In order to enhance the understanding of GBS-EOD prevention, the most recent guidelines updates by the American College of Obstetricians and Gynecologists (ACOG) and American Academy of Pediatrics (AAP) in 2019-2020 are summarized in this article.

Oral probiotics to reduce vaginal group B streptococcal colonization in late pregnancy

This study aimed to evaluate the potential of oral probiotics to eradicate vaginal GBS colonization during the third trimester of pregnancy. We screened 1058 women for GBS colonization at 33–37 gestational weeks using a combination of vaginal-to-rectal swab and culture-based methods. Women who tested GBS positive were randomized to either the verum group, receiving a dietary probiotic supplement of four viable strains of Lactobacillus twice-daily for 14 days, or to the placebo group. Women underwent follow-up smears, whereat GBS colonization upon follow-up was considered the primary endpoint. We found that 215 women (20.3%) were positive for GBS upon screening, of which 82 (38.1%) were eligible for study inclusion; 41 (50%) of these were randomized to the verum and placebo groups each. After treatment, 21/33 (63.6%) members of the verum group, and 21/27 (77.8%) of the placebo group were still GBS positive (p = 0.24). Four (9.8%) women in the verum group and one (2.4%) in the placebo group experienced preterm birth (p = 0.20); smokers showed significantly higher rates of preterm birth (p = 0.03). Hence, the findings did not support the hypothesis that oral probiotics can eradicate GBS during pregnancy, although we observed a trend toward reduced GBS persistence after probiotic intake.

Group B Streptococcal Bacteriuria in Pregnancy: An Evidence-Based, Patient-Centered Approach to Care

Screening and management of group B streptococcus (GBS) bacteriuria in pregnancy aims to reduce the incidence of pyelonephritis and GBS-related neonatal morbidity and mortality. Universal screening and management of GBS bacteriuria in pregnancy are standards of care in the United States; however, some women may decline guideline-based recommendations for screening, treatment, or intrapartum antibiotic prophylaxis. This article uses a case study approach to discuss evidence-based, patient-centered care for GBS bacteriuria in pregnancy as well as ethical incorporation of individual patient preferences and values.

A Retrospective Review of Neonatal Sepsis among GBS-Colonized Women Undergoing Planned Cesarean Section after Labor Onset or Rupture of Membranes

Background

Sepsis is a leading cause of mortality and morbidity in neonates, with group B streptococcus (GBS) remaining the most frequent pathogen isolated from term infants. Surveillance data showed that the majority of cases of early-onset GBS disease were neonates born to women who either received no or suboptimal intrapartum antibiotic prophylaxis with a notable portion of those women having a missed opportunity to receive ≥4 hours of chemoprophylaxis. Women planning delivery by cesarean section who present in labor or rupture of membranes prior to their scheduled surgery are unlikely to receive optimal GBS chemoprophylaxis and thus their neonates are at risk of having sepsis. Materials and Methods. A retrospective cohort study of women-infant dyads was extracted from the Consortium on Safe Labor dataset. Women who had an unlabored cesarean section at ≥37 + 0 week gestation were selected and divided into four groups based on GBS status and timing of cesarean section with respect to onset of labor or rupture of membranes. The rate of neonatal sepsis and the patterns of intrapartum antibiotic chemoprophylaxis were determined.

Results

The sepsis rate (4.5%) among neonates of GBS-colonized women having their unlabored cesarean section after onset of labor or rupture of membranes was significantly higher than that in any other group in this study. In this group, 9.4% of women received chemoprophylaxis for ≥4 hours, while 31% had a missed opportunity to receive ≥4 hours of chemoprophylaxis.

Conclusion

This study suggests that neonates of GBS-colonized women having a planned cesarean section after onset of labor or rupture of membranes are at increased risk of having a sepsis diagnosis. This finding suggest the need for additional studies to assess the risk of sepsis among neonates of women in this group.

Intrapartum beta-lactam antibiotics for preventing group B streptococcal early-onset disease: can we abandon the concept of 'inadequate' intrapartum antibiotic prophylaxis?

Introduction: Neonatal sepsis remains a serious and potentially fatal illness. Intrapartum antibiotic prophylaxis (IAP) prevents group B streptococcal (GBS) early-onset sepsis. The optimal duration of IAP (adequate IAP) to reduce vertical transmission of GBS has been debated. Understanding the mechanism of action of IAP may help in minimizing neonatal evaluation and unnecessary antibiotic use.Areas covered: In recent years, several studies on pharmacokinetics and clinical use of IAP have been published. Although penicillin and ampicillin are the most preferred antibiotics, the clinical efficacy of non-beta-lactam antibiotics, including clindamycin and vancomycin, used in cases of penicillin anaphylaxis-associated allergy, remains debatable. This is a narrative review of the literature regarding the impact of 'inadequate' IAP on the clinical management of women and newborns.Expert opinion: Recent evidence suggests that 'inadequate' IAP with beta-lactams is more effective in preventing vertical transmission of GBS than previously thought. Newborns exposed to intrapartum beta-lactams and who are asymptomatic at birth are likely uninfected, irrespective of IAP duration before delivery. Hence, we may abandon the concept of 'inadequate' IAP with beta-lactams in early-onset GBS sepsis, relying primarily on clinical signs observed at birth for managing IAP-exposed neonates.

The Interaction between Phagocytes and Streptococcus agalactiae (GBS) Mediated by the Activated Complement System is the Key to GBS Inducing Acute Bacterial Meningitis of Tilapia

Simple Summary

Streptococcus agalactiae (GBS) is a serious threat to farmed tilapia, which results in high mortality and seriously hinders tilapia farming development. The pathogenic mechanism of tilapia infected with GBS which die rapidly in production remains unknown. We provided a comprehensive comparative analysis of the tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons YM001 lost its pathogenicity to tilapia. Our study provided a comprehensive cognition of the mechanism of acute bacterial meningitis caused by GBS.

Abstract

Streptococcus agalactiae is an important pathogen for tilapia meningitis. Most of the infected tilapia die rapidly in production, when the way to study the pathogenic mechanism of bacteria on host through chronic infection in laboratory is not comprehensive and accurate enough to elucidate the real pathogenic mechanism. The objective of this study was to investigate the mechanism of acute bacterial meningitis of tilapia caused by Streptococcus agalactiae (GBS), and provide a theoretical basis for its prevention and treatment. Duel RNA-seq, proteome analysis, histopathological analysis, plasma biochemical indexes, and blood routine examination were performed on tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The results showed that the contents of white blood cell (WBC), monocytes (MON), and neutrophil (NEU) were significantly lower in the HN016 group compared to that in the YM001 group (p < 0.05). Histopathological examination showed that there were partially lesions in the examined tissues of tilapia infected by HN016, while no obvious histopathological changes occurred in the YM001 group. The differential expressed genes (DEGs) and differential expressed proteins (DEPs) between YM001 and HN016 were mainly enriched in the beta-lactam resistance pathway (oppA1, oppA2, oppB, oppC, oppD, oppF, and mrcA). The DEGs DEPs between YM001-brain and HN016-brain were mainly enriched in the complement and coagulation cascades signaling pathway (C2a, c4b, c3b, c7, CD59, ITGB2, and ITGAX). The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is the key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons for why YM001 lost its pathogenicity to tilapia.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 782

Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."

Are postnatal ampicillin levels actually related to the duration of intrapartum antibiotic prophylaxis prior to delivery? A pharmacokinetic study in 120 neonates

OBJECTIVE

To assess ampicillin levels according to the duration of intrapartum antibiotic prophylaxis (IAP).

DESIGN

Prospective cohort single-centre study.

SETTING

Tertiary care centre (Modena, Italy).

PATIENTS

120 neonates≥35 weeks' gestation exposed to IAP.

INTERVENTIONS

Neonates were divided into four groups, according to the duration of IAP prior to delivery: group 1 (n=30; <1 hour), group 2 (n=30; ≥1 and <2 hours), group 3 (n=30; ≥2 and <4 hours) and group 4 (n=30; ≥2 doses, ≥4 hours).

MAIN OUTCOME MEASURES

Blood samples were collected at delivery (from the umbilical cord) and at age 4 hours (from a peripheral vessel).

RESULTS

Median duration of IAP was 121 min (range 7-2045 min). Median ampicillin levels in umbilical cord blood were 10.4 µg/mL (IQR 6.4-14.9) and in peripheral blood were 4.7 µg/mL (IQR 2.8-6.4µg/mL). Umbilical cord blood levels reached a peak approximately 30 min after IAP and then declined significantly (p<0.001). Peripheral blood levels did not differ among study groups. Neonates exposed to a full loading dose (n=115) had peripheral blood levels 2.5-70 times higher than the minimal inhibitory concentration for group B streptococcus. There was no relationship between neonatal ampicillin concentrations and the duration of IAP prior to delivery (β=-0.0003, 95% CI -0.02 to 0.001, p=0.680).

CONCLUSIONS

Ampicillin levels reach a peak in the umbilical cord blood within 30 min of intrapartum administration. After a full loading dose, bactericidal levels persist for at least 4 hours after birth and seem independent of the duration of IAP prior to delivery.

C reactive protein in healthy term newborns during the first 48 hours of life

BACKGROUND

Early-onset neonatal sepsis (EOS) is a serious and potentially life-threatening disease in newborns. C reactive protein (CRP) is the most used laboratory biomarker for the detection of EOS. Little is known about normal reference values of CRP during the perinatal period as several factors are able to influence it.

OBJECTIVES

To identify an appropriate range of CRP values in healthy term newborns during the first 48 hours of life.

DESIGN

CRP determination was performed in 859 term newborns at 12, 24 and 48 hours of life. Mode of delivery, maternal vaginal culture results, intrapartum antimicrobial prophylaxis (IAP) and other perinatal variables were recorded.

RESULTS

CRP mean values were significantly higher at 48 hours (4.10 mg/L) than at both 24 (2.30 mg/L) and 12 hours of life (0.80 mg/L). CRP levels were affected by a number of perinatal proinflammatory variables. In particular, CRP mean values were significantly higher in babies born by vaginal delivery (3.80 mg/L) and emergency caesarean section (3.60 mg/L) than in babies born by elective caesarean section (2.10 mg/L). Completed course of IAP led to lower CRP mean values (2.90 mg/L) than IAP not completed (3.80 mg/L) or not performed (4.70 mg/L).

CONCLUSIONS

Postnatal age and mode of delivery significantly influence CRP values. Reliable reference values are crucial in order to obtain an adequate diagnostic accuracy.

Of the Phrensy: an update on the epidemiology and pathogenesis of bacterial meningitis in the pediatric population

In the past century, advances in antibiotics and vaccination have dramatically altered the incidence and clinical outcomes of bacterial meningitis. We review the shifting epidemiology of meningitis in children, including after the implementation of vaccines that target common meningitic pathogens and the introduction of intrapartum antibiotic prophylaxis offered to mothers colonized with Streptococcus agalactiae. We also discuss what is currently known about the pathogenesis of meningitis. Recent studies of the human microbiome have illustrated dynamic relationships of bacterial and viral populations with the host, which may potentiate the risk of bacterial meningitis.

Group B streptococcus infections in neonates admitted to a German NICU: Emphasis on screening and adherence to pre-analytical recommendations

BACKGROUND

Infections by group B streptococci (GBS), e.g. Streptococcus agalactiae, presenting as early-onset disease (EOD) or late-onset disease (LOD), are leading causes of severe infections in newborn and premature patients. Although screening and intra partum antibiotic prophylaxis are frequently performed, vertically transmitted GBS remain a challenge for pediatrics.

AIMS

In order to prevent or reduce potential life-threatening events, this study retrospectively investigated epidemiological, microbiological and clinical aspects of infants admitted to the Division of Neonatology at the Department of Pediatrics at the University Hospital Frankfurt, Germany (UHF).

STUDY DESIGN AND SUBJECTS

Between January 2010 and January 2016, perinatal GBS screening status, clinical presentation of EOD or LOD and therapeutic management of neonates admitted to UHF were retrospective analysed. Infants tested positive for GBS within their first three months of life were included; patient data were obtained from the chart report. Severity of neonatal disease was analysed by using the NEOMOD and CRIB score.

RESULTS

108 GBS infected infants born to 105 mothers were observed. N=101 of them (93.5%) presented with EOD, whereof n=9 (10%) primarily presented with pneumonia or pneumothorax. In 82 (78%) mothers of infected infants GBS status was unknown prior to hospitalization of the neonate. 3/108 (2.8%) infants died from GBS septicemia.

CONCLUSION

Avoidance of GBS transmission sub partu is the key issue in preventing neonatal GBS infection and should be the focus of preventive strategies. Our results highlight the impact of perinatal screening.

Appropriateness of Intrapartum Antibiotic Prophylaxis to Prevent Neonatal Group B Streptococcus Disease

The aims of this study were to describe the adherence to CDC guidelines for intrapartum antibiotic prophylaxis (IAP) and to identify possible factors influencing noncompliance with guidelines. We conducted a retrospective study in Italy. Our cohort included women in whom antenatal Group B Streptococcus (GBS) screening was not performed, was performed, but results were not available at the time of labor or delivery and women who were positive for GBS colonization. The indications for complete execution of IAP according to revised CDC guidelines was evaluated. It was considered adequate when performed with a recommended antibiotic at least four hours prior to delivery. The cohort included 902 women. Among those who had performed rectal and vaginal swabs (or recto-vaginal swabs), results were available in 86.9% of vaginal swabs and in 87.1% of rectal swabs and GBS was detected in 59.8% of vaginal swabs and in 71% of rectal swabs. 49.2% women had indication for GBS prophylaxis. Among these, 91.1% received an antibiotic during labor. Totally appropriate IAP was performed in 36.3% deliveries, an inappropriate antibiotic was administered in 10.4% women, the remaining 45.3% women received partially appropriate IAP; of these, 15.5% had received antibiotics through an inappropriate route of administration, 18.2% an inappropriate dosage regimen. Overall, 27.5% women received intrapartum ampicillin with inappropriate timing. Multivariate analysis showed that totally appropriate prophylaxis was significantly more likely in women who had no previous live birth, who had vaginal delivery, and a positive result at antenatal GBS screening. Despite satisfactory GBS screening implementation, there is still a substantial gap between optimal and actual IAP. We hypothesize that the complexity of the CDC guidelines may partially explain this shortcoming. Future efforts will include initiatives focused at enabling and reinforcing adherence to evidence-based prevention practices.

Assessing Early Life Factors for Eosinophilic Esophagitis: Lessons From Other Allergic Diseases

OPINION STATEMENT

Few studies have been conducted to investigate possible early life determinants for eosinophilic esophagitis. An improved understanding of the etiologic factors implicated in disease development would further elucidate possible disease pathogenesis, inform therapeutic targets for disease treatment, and identify possible modifiable factors for disease prevention in genetically susceptible individuals. Although eosinophilic esophagitis is increasing in incidence and prevalence, the disease remains relatively rare, posing challenges for studying etiologic factors in disease development. Eosinophilic esophagitis is believed to be antigen-mediated, and most patients with EoE have concomitant atopic disease. In recent years, the evolution of our understanding of possible etiologic mechanisms in allergic disease has been informed by our understanding of how early life perturbations can lead to dysbiosis in the colonization of the microflora in the gastrointestinal tract and subsequent dysregulated immune development. Perturbations include factors such as antibiotic use, including prenatal, intra-antepartum, and infancy use of antibiotics, Cesarean delivery, preterm delivery, and neonatal intensive care admission. This article provides a review of these recent developments, as they relate to atopic disease, to inform future directions in the study of early life etiologic factors in the development of eosinophilic esophagitis.

Oral antibiotics increase blood neutrophil maturation and reduce bacteremia and necrotizing enterocolitis in the immediate postnatal period of preterm pigs

Immature immunity may predispose preterm neonates to infections and necrotizing enterocolitis (NEC). Intravenous antibiotics are frequently given to prevent and treat sepsis, while oral antibiotics are seldom used. We hypothesized that oral antibiotics promote maturation of systemic immunity and delay gut bacterial colonization and thereby protect preterm neonates against both NEC and bacteremia in the immediate postnatal period. Preterm pigs were given formula and administered saline (CON) or broad-spectrum antibiotics orally (ORA) or systemically (SYS) for 5 d after birth. Temporal changes in blood parameters and bacterial composition in the intestine, blood and immune organs were analyzed. Newborn preterm pigs had few blood neutrophils and a high frequency of progenitor cells. Neutrophils gradually matured after preterm birth with increasing CD14 and decreasing CD172a expressions. Preterm neutrophil and monocyte TLR2 expression and TLR2-mediated blood cytokine responses were low relative to adults. ORA pigs showed enhanced blood neutrophil maturation with reduced cell size and CD172a expression. Only ORA pigs, but not SYS pigs, were protected from a high density of gut Gram-positive bacteria, high gut permeability, Gram-positive bacteremia and NEC. Neonatal oral antibiotics may benefit mucosal and systemic immunity via delayed gut colonization and enhanced blood neutrophil maturation just after preterm birth.

The impact of early life gut colonization on metabolic and obesogenic outcomes: what have animal models shown us?

The rise in the occurrence of obesity to epidemic proportions has made it a global concern. Great difficulty has been experienced in efforts to control this growing problem with lifestyle interventions. Thus, attention has been directed to understanding the events of one of the most critical periods of development, perinatal life. Early life adversity driven by maternal obesity has been associated with an increased risk of metabolic disease and obesity in the offspring later in life. Although a mechanistic link explaining the relationship between maternal and offspring obesity is still under investigation, the gut microbiota has come forth as a new factor that may play a role modulating metabolic function of both the mother and the offspring. Emerging evidence suggests that the gut microbiota plays a much larger role in mediating the risk of developing non-communicable disease, including obesity and metabolic dysfunction in adulthood. With the observation that the early life colonization of the neonatal and postnatal gut is mediated by the perinatal environment, the number of studies investigating early life gut microbial establishment continues to grow. This paper will review early life gut colonization in experimental animal models, concentrating on the role of the early life environment in offspring gut colonization and the ability of the gut microbiota to dictate risk of disease later in life.

Diagnosis and management of group B streptococcus in pregnancy

Group B streptococcus (GBS) can cause significant maternal and neonatal morbidity. Over the past 30 years, reductions in early-onset GBS neonatal sepsis in the United States have been attributable to the guidelines from the Centers for Disease Control and Prevention for antepartum screening and treating this organism during labor. This article highlights the clinical implications, screening, diagnosis, prophylactic interventions, and future therapies for mothers with GBS during the peripartum period.

Antibiotic treatment of pregnant non-obese diabetic mice leads to altered gut microbiota and intestinal immunological changes in the offspring

The intestinal microbiota is important for tolerance induction through mucosal immunological responses. The composition of the gut microbiota of an infant is affected by environmental factors such as diet, disease and antibiotic treatment. However, already in utero, these environmental factors can affect the immunological development of the foetus and influence the future gut microbiota of the infant. To investigate the effects of antibiotic treatment of pregnant mothers on the offspring's gut microbiome and diabetes development, we treated non-obese diabetic (NOD) mice with a cocktail of antibiotics during gestation and the composition of the gut microbiota, diabetes incidence and major gut-related T lymphocyte populations were investigated in the offspring. We observed a persistent reduction in the general diversity of the gut microbiota in the offspring from NOD mothers treated with antibiotics during gestation compared with offspring from control mothers. In addition, by clustering the present bacterial taxa with principal component analysis, we found a differential clustering of gut microbiota in the offspring from NOD mothers treated with antibiotics during gestation compared with offspring from control mothers. Offspring from NOD mothers treated with antibiotics during gestation also showed some immunological alterations in the gut immune system, which could be related to the diversity of the gut microbiome and influence modulation of diabetes development at 20 weeks. Our data point out maternal derangement of the intestinal microbiota as a potential environmental risk factor for T1D development.

Intrapartum antibiotic prophylaxis for Group B Streptococcus: has the time come to wait more than 4 hours?

Despite progress in preventing infant group B streptococcal disease, group B streptococcus remains the leading cause of early-onset neonatal sepsis in the United States. Fortunately, most women who are colonized with group B streptococcus receive therapy and antibiotic prophylaxis is effective. However, the only factor associated with missed chemoprophylaxis is the short duration of time between hospital admission and delivery. Although antibiotic prophylaxis given for at least 2 hours shows some pharmacological benefit, the most effective method of preventing early-onset group B streptococcus disease is 4 hours of therapy. Intrapartum management strategies might be modified to improve the efficacy of antibiotic exposure. Obstetricians should consider strengthening the beneficial effect of intrapartum antibiotic prophylaxis for infants exposed to group B streptococcus by providing at least 4 hours of treatment coverage.