Tag Archives: Neonatal Intensive Care

Identifying what makes some gut bacteria strains life-threatening in pre-term babies

Researchers from the Quadram Institute and University of East Anglia have identified what makes some strains of gut bacteria life-threatening in pre-term babies.

The findings will help identify and track dangerous strains and protect vulnerable neonatal babies.

A major threat to neonatal babies with extremely low birth weight is necrotizing enterocolitis (NEC).

Rare in full-term babies, this microbial infection exploits vulnerabilities destroying gut tissue leading to severe complications. Two out of five cases are fatal.

One bacterial species that causes especially sudden and severe disease is Clostridium perfringens. These are common in the environment and non-disease-causing strains live in healthy human guts.

So what makes certain strains so dangerous in preterm babies?

Prof Lindsay Hall and Dr Raymond Kiu from the Quadram Institute and UEA led the first major study on C. perfringens genomes from preterm babies, including some babies with necrotizing enterocolitis.

if (g_displayableSlots.mobileMiddleMrec) {
pushDisplayAd(function() { googletag.display(‘div-gpt-mobile-middle-mrec’); });
}

The research team analyzed C. perfringens genomes from the faecal samples of 70 babies admitted to five UK Neonatal Intensive Care Units (NICUs).

Based on genomic similarities, they found one set had a lower capacity to cause disease. This allowed a comparison with the more virulent strains.

The less virulent group lacked genes responsible for production of a toxin called PFO and other factors needed for colonization and survival.

This study has begun to construct genomic signatures for C. perfringens associated with healthy preterm babies and those with necrotizing enterocolitis.

Exploring genomic signatures from hundreds of Clostridium perfringens genomes has allowed us potentially to discriminate between ‘good’ bacterial strains that live harmlessly in the preterm gut, and ‘bad’ ones associated with the devastating and deadly disease necrotizing enterocolitis.

We hope the findings will help with ‘tracking’ deadly C. perfringens strains in a very vulnerable group of patients – preterm babies.”

Prof Lindsay Hall, UEA’s Norwich Medical School and the Quadram Institute

Larger studies, across more sites and with more samples may be needed but this research could help identify better ways to control necrotizing enterocolitis.

The team previously worked alongside Prof Paul Clarke and clinical colleagues at the Norfolk and Norwich University Hospital NICU. And they demonstrated the benefits of providing neonatal babies with probiotic supplements.

The enterocolitis gut microbiome of neonatal infants is significantly disrupted, making it susceptible to C. perfringens overgrowth.

Prof Hall said: “Our genomic study gives us more data that we can use in the fight against bacteria that cause disease in babies – where we are harnessing the benefits of another microbial resident, Bifidobacterium, to provide at-risk babies with the best possible start in life.”

Dr Raymond Kiu, from the Quadram Institute, said: “Importantly, this study highlights Whole Genome Sequencing as a powerful tool for identifying new bacterial lineages and determining bacterial virulence factors at strain level which enables us to better understand disease.”

This research was supported by the Biotechnology and Biological Sciences Research Council, part of UKRI, and the Wellcome Trust.

The study was led by researchers at Quadram Institute and the University of East Anglia, in collaboration with colleagues at Imperial College, London, the University of Glasgow, the University of Cambridge, Newcastle University and Northumbria University.

‘Particular genomic and virulence traits associated with preterm infant-derived toxigenic Clostridium perfringens strains’ is published in Nature Microbiology.

Source:
Journal reference:

Kiu, R., et al. (2023). Particular genomic and virulence traits associated with preterm infant-derived toxigenic Clostridium perfringens strains. Nature Microbiology. doi.org/10.1038/s41564-023-01385-z.

Maternal and perinatal outcomes of women infected with SARS-CoV-2 during the Omicron wave in Italy

In a recent study published in the Clinical Microbiology and Infection, researchers assessed the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on pregnant women during the Omicron wave.

Study: Vaccination against SARS-CoV-2 in pregnancy during the Omicron wave: the prospective cohort study of the Italian obstetric surveillance system. Image Credit: GolF2532/Shutterstock
Study: Vaccination against SARS-CoV-2 in pregnancy during the Omicron wave: the prospective cohort study of the Italian obstetric surveillance system. Image Credit: GolF2532/Shutterstock

Background

During the coronavirus disease 2019 (COVID-19) pandemic, pregnant women were more likely than the general population to develop severe COVID-19. In utero mother-to-child viral transmission was shown to be uncommon, and infected mothers demonstrated a strong immune response with anti-SARS-CoV-2 antibodies passed on to newborns.

Despite many studies indicating a substantial maternal antibody response to SARS-CoV-2 immunization and the absence of safety issues, the vaccination rate among pregnant women remained lower than that of the general population. Only a few studies have been undertaken to date on the impact of the SARS-CoV-2 Omicron variant on unvaccinated and vaccinated pregnant women.

About the study

In the present study, researchers compared the perinatal and maternal outcomes of SARS-CoV-2-infected women in Italy during the SARS-CoV-2 Omicron variant wave based on their vaccination protection.

The current national prospective cohort research involved pregnant women who tested COVID-19-positive within seven days of hospitalization in any Italian maternity unit between January 1 and May 31 2022. In addition, women reported whether they had received the SARS-CoV-2 vaccine, as well as the when (before and/or at the time of pregnancy) and how many doses were received.

The primary outcome measure was SARS-CoV-2 disease severity, classified as mild, moderate, or severe. The two most severe severity categories, determined by pneumonia diagnosis, were grouped together for statistical analysis as “moderate or severe COVID-19 disease” (MSCD). Secondary outcomes comprised preterm birth, stillbirth, delivery mode, admission to the neonatal intensive care unit (NICU), and early neonatal mortality before hospital release.

MSCD protection was taken into account as an exposure variable. Women vaccinated with a minimum of one vaccine dose at the time of pregnancy, and those vaccinated with the full vaccine schedule and the first booster vaccine were protected against MSCD. On the other hand, unvaccinated women and participants who were vaccinated with either one or two vaccine doses prior to pregnancy and tested positive for SARS-CoV-2 at 22 or more gestational weeks were deemed unprotected. Women with incomplete vaccination information and those who were vaccinated with one or two doses prior to pregnancy and who tested positive for SARS-CoV-2 at less than 22 gestational weeks were deemed “unknown in terms of protective status.”

Results

Between January 1 and May 31, 2022, a total of 2,774 women who tested positive for SARS-CoV-2 within seven days of hospitalization were enrolled. Information was available about the protection status of 2147 women, while no significant clinical or socio-demographic variations were noted between these women and the entire cohort.

According to the study’s definition, almost 1,069 (49.8%) individuals were protected against MSCD. Of them, 74 were vaccinated with one vaccine during pregnancy, while 596 received two, including a minimum of one dose administered during pregnancy, while 327 received their first booster. In contrast, 1,078 women were deemed unprotected, including 989 women who were unvaccinated and 89 who tested positive for SARS-CoV-2 at 22 or more weeks of gestation after receiving one or two doses before pregnancy. All except 26 women were immunized with the conventional vaccinations alone or in conjunction with messenger ribonucleic acid (mRNA) vaccines.

Compared to protected women, unprotected women displayed a higher likelihood of being younger, less educated, of foreign nationality, and symptomatic. Also, 96.4% were hospitalized for childbirth or obstetrical causes, whereas 3.6% were hospitalized due to COVID-19. Eight of the latter acquired severe disease, 12 developed a moderate disease, and 58 developed a mild disease.

MSCD illness was uncommon overall but more prevalent among unprotected women than among protected women. Among the 41 MSCD cases, 27 of 29 unprotected women had not received any vaccine, while two were vaccinated with two doses prior to pregnancy. Three of the 12 protected women received the booster, while nine received two doses, among which the first was received before and the second was received during pregnancy.

Among unprotected women, seven out of eight severe infection cases and one maternal fatality occurred. COVID-19 pneumonia was deemed the cause of death, reported two weeks after delivery. Unprotected women had a greater incidence of MSCD compared to protected women, Asian women, and those with a history of comorbidities.

Sensitivity analysis revealed that unprotected women had considerably higher MSCD risk than protected women. Furthermore, 8.7% of newborns were born preterm, predominantly late preterm, with no significant variations between unprotected and protected women, but C-section was reported in 34.4% and 29.3% of women, respectively. The rate of preterm birth was greater among MSCD-infected women compared to those with milder cases and those with CS. Also, out of 619 CS cases, five were urgent/emergent due to COVID-19, and all involved MSCD-affected women.

Conclusion

Overall, the study findings documented a low prevalence of severe SARS-CoV-2 infection in pregnant women and considerable efficacy of the COVID-19 vaccine in providing protection. These statistics can serve as the foundation for informing pregnant women uncertain about the vaccine’s efficacy and demonstrating the importance of vaccination in protecting their newborns.

Journal reference: