Microbial Infections and Antimicrobial Use in Neonates and Infants

Microbiota plays a crucial role in intestinal maturation in preterm newborns. The clinical manifestation of the immaturity of the gastro-intestinal tract is called feeding intolerance (FI). This condition may resolve spontaneously or dramatically evolve into necrotizing enterocolitis. One of the most challenging tasks for the neonatologist is to identify those neonates that will develop the disease early in order to adequately provide nutrition to these patients, from the very first hours of life. A close interplay between the maturity of the gastro-intestinal tract and gut microbiota has been described; however, in preterm neonates, this relationship is still undefined. We analyzed the bacterial composition of stool samples, collected early in life, from 30 preterm newborns classified as intolerant or tolerant according to the degree of readiness of the gastro-intestinal tract to receive enteral nutrition. The Pielou evenness index was significantly increased in intolerant compared with tolerant newborns. Data corrected for confounding variables confirmed that the occurrence of gut maturation was independently influenced by Pielou evenness at birth. A lower bacterial diversity very early in life is associated with improved feeding tolerance in preterm newborns. The abundance analysis showed that neonates not ready to receive enteral nutrition for feeding intolerance show, after birth, an increased abundance of Proteobacteria, Lachnospiracae, Enterobacter and Acinetobacter. We can argue that those are the taxa that prevent the establishment of pioneer bacteria. A lower alpha-diversity, in the first days of life, may facilitate the seeding of beneficial pioneer bacteria that, in turn, drive healthy microbial colonization during neonatal life. Full article

Background: The high prevalence of suspected early-onset neonatal sepsis among preterm infants leads to immediate antibiotic administration upon admission. Notably, most blood cultures for suspected early-onset neonatal sepsis do not yield a causative pathogen. This study aimed to assess polymerase chain reaction (PCR) targeting the variable region V4 of the 16S ribosomal gene (16S rDNA) and Sanger sequencing for bacterial identification in preterm infants with suspected early-onset neonatal sepsis. Methods: Therefore, this prospective study was conducted. Preterm infants with suspected early-onset neonatal sepsis were included in this study. The three groups were formed based on the risk of infection and clinical sepsis. Blood samples were collected upon admission to the neonatal unit for culture and molecular analysis. PCR amplification and subsequent Sanger sequencing of the V4 region of the 16S rDNA were performed. Results: Twenty-eight patients were included in this study. Blood cultures were negative in 100% of the patients. Amplification and sequencing of the V4 region identified bacterial genera in 19 patients across distinct groups. The predominant taxonomically identified genus was Pseudomonas. Conclusions: Amplifying the 16S rDNA variable region through PCR and subsequent Sanger sequencing in preterm neonates with suspected early-onset neonatal sepsis can enhance the identification of microbial species that cause infection, especially in negative cultures. Full article

Background: The birthrate of Black preterm (BPT) infants is 65% higher than White preterm (WPT) infants with a BPT mortality that is 2.3 times higher. The incidence of culture-positive late-onset sepsis is as high as 41% in very-preterm infants. The main purpose of this study was to examine thermal gradients and the heart rate in relation to the onset of infection. This report presents disparities in very-preterm infection incidence, bacteria, and mortality data amongst BPT and WPT infants. Methods: 367 preterms born at <32 weeks gestational age (GA) between 2019–2023 in five neonatal intensive care units (NICUs) were enrolled to study the onset of infections and dispositions; REDCap data were analyzed for descriptive statistics. Results: The 362 infants for analyses included 227 BPTs (63.7%) and 107 WPTs (29.6%), with 28 infants of other races/ethnicities (Hispanic, Asian, and other), 50.6% female, mean GA of 27.66 weeks, and 985.24 g birthweight. BPT infants averaged 968.56 g at birth (SD 257.50), and 27.68 (SD 2.07) weeks GA, compared to WPT infants with a mean birthweight of 1006.25 g (SD 257.77, p = 0.2313) and 27.67 (SD 2.00, p = 0.982) weeks GA. Of the 426 episodes of suspected infections evaluated across all the enrolled infants, the incidence of early-onset sepsis (EOS) was 1.9%, with BPT infants having 2.50 times higher odds of EOS than WPT infants (p = 0.4130, OR (odds ratio) = 2.50, p_or = 0.408). The overall incidence of late-onset sepsis (LOS) was 10.8%, with LOS in 11.9% of BPT infants versus 9.3% (p = 0.489, OR = 1.21, p_or = 0.637) of WPT infants. BPT infants made up 69.2% of the 39 infants with Gram-positive infections vs. 25.6% for WPT infants; 16 infants had Gram-negative culture-positive infections, with 81.2% being BPT infants versus 18.8% being WPT infants. Of the 27 urinary tract infections, 78% were in BPTs. The necrotizing enterocolitis incidence was 6.9%; the incidence in BPT infants was 7.5% vs. 6.5% in WPT infants. The overall mortality was 8.3%, with BPTs at 8.4% vs. WPT infants at 9.3%, (p = 0.6715). Conclusions: BPTs had a higher rate of positive cultures, double the Gram-negative infections, a much higher rate of urinary tract infections, and a higher rate of mortality than their WPT counterparts. This study emphasizes the higher risk of morbidity and mortality for BPTs. Full article

Background: There are wide variations in antibiotic use in neonatal intensive care units (NICUs). Limited data are available on antimicrobial stewardship (AS) programs and long-term maintenance of AS interventions in preterm very-low-birth-weight (VLBW) infants. Methods: We extended a single-centre observational study carried out in an Italian NICU. Three periods were compared: I. “baseline” (2011–2012), II. “intervention” (2016–2017), and III. “maintenance” (2020–2021). Intensive training of medical and nursing staff on AS occurred between periods I and II. AS protocols and algorithms were maintained and implemented between periods II and III. Results: There were 111, 119, and 100 VLBW infants in periods I, II, and III, respectively. In the “intervention period”, there was a reduction in antibiotic use, reported as days of antibiotic therapy per 1000 patient days (215 vs. 302, p < 0.01). In the “maintenance period”, the number of culture-proven sepsis increased. Nevertheless, antibiotic exposure of uninfected VLBW infants was lower, while no sepsis-related deaths occurred. Our restriction was mostly directed at shortening antibiotic regimens with a policy of 48 h rule-out sepsis (median days of early empiric antibiotics: 6 vs. 3 vs. 2 in periods I, II, and III, respectively, p < 0.001). Moreover, antibiotics administered for so-called culture-negative sepsis were reduced (22% vs. 11% vs. 6%, p = 0.002), especially in infants with a birth weight between 1000 and 1499 g. Conclusions: AS is feasible in preterm VLBW infants, and antibiotic use can be safely reduced. AS interventions, namely, the shortening of antibiotic courses in uninfected infants, can be sustained over time with periodic clinical audits and daily discussion of antimicrobial therapies among staff members. Full article

Healthcare settings, especially intensive care units, can provide an ideal environment for the transmission of pathogens and the onset of outbreaks. Many factors can contribute to the onset of an epidemic in a neonatal intensive care unit (NICU), including neonates’ vulnerability to healthcare-associated infections, especially for those born preterm; facility design; frequent invasive procedures; and frequent contact with healthcare personnel. Outbreaks in NICUs are one of the most relevant problems because they are often caused by multidrug-resistant organisms associated with increased mortality and morbidity. The prompt identification of an outbreak, the subsequent investigation to identify the source of infection, the risk factors, the reinforcement of routine infection control measures, and the implementation of additional control measures are essential elements to contain an epidemic. Full article

Sepsis remains the second cause of death among neonates after the pathological consequences of extreme prematurity. In this review we summarized knowledge about pathogens causing early-onset sepsis (EOS) and late-onset sepsis (LOS), the role of perinatal risk factors in determining the EOS risk, and the tools used to reduce unnecessary antibiotics. New molecular assays could improve the accuracy of standard blood cultures, providing the opportunity for a quick and sensitive tool. Different sepsis criteria and biomarkers are available to date, but further research is needed to guide the use of antibiotics according to these tools. Beyond the historical antibiotic regimens in EOS and LOS episodes, antibiotics should be based on the local flora and promptly modulated if specific pathogens are identified. The possibility of an antibiotic lock therapy for central venous catheters should be further investigated. In the near future, artificial intelligence could help us to personalize treatments and reduce the increasing trend of multidrug-resistant bacteria. Full article

Vulvovaginal candidiasis (VVC) is a common condition that can lead to significant discomfort, affecting approximately 70–75% of women at least once in their lives. During pregnancy, the prevalence of VVC is estimated to be around 20%, peaking at about 30% in the third trimester, with a number of specific risk factors predisposing to yeast infection being identified and needing elucidation. This review aims to provide updated knowledge on candidiasis during pregnancy, addressing risk factors and maternal and neonatal outcomes, as well as discussing optimal therapeutic strategies to safeguard mothers and newborns. The bibliographic search involved two biomedical databases, PubMed and Embase, without imposing time limits. Among all Candida spp., Candida albicans remains the most frequent causative species. The hyperestrogenic environment of the vaginal mucosa and reduced immune defenses, physiological effects of pregnancy, create conditions favorable for Candida spp. vaginal colonization and hence VVC. Recent evidence shows an association between VVC and adverse obstetric outcomes, including premature membrane rupture (PROM), chorioamnionitis, preterm birth, and puerperal infections. Prompt and effective management of this condition is therefore crucial to prevent adverse obstetric outcomes, maternal–fetal transmission, and neonatal disease. Additional studies are required to confirm the benefits of systemic treatment for maternal candida infection or colonization in preventing premature birth or neonatal systemic candidiasis. Full article

The fear of missing sepsis episodes in neonates frequently leads to indiscriminate use of antibiotics, and prescription program optimization is suggested for reducing this inappropriate usage. While different authors have studied how to reduce antibiotic overprescription in the case of early onset sepsis episodes, with different approaches being available, less is known about late-onset sepsis episodes. Biomarkers (such as C-reactive protein, procalcitonin, interleukin-6 and 8, and presepsin) can play a crucial role in the prompt diagnosis of late-onset sepsis, but their role in antimicrobial stewardship should be further studied, given that different factors can influence their levels and newborns can be subjected to prolonged therapy if their levels are expected to return to zero. To date, procalcitonin has the best evidence of performance in this sense, as extrapolated from research on early onset cases, but more studies and protocols for biomarker-guided antibiotic stewardship are needed. Blood cultures (BCs) are considered the gold standard for the diagnosis of sepsis: positive BC rates in neonatal sepsis workups have been reported as low, implying that the majority of treated neonates may receive unneeded drugs. New identification methods can increase the accuracy of BCs and guide antibiotic de-escalation. To date, after 36–48 h, if BCs are negative and the baby is clinically stable, antibiotics should be stopped. In this narrative review, we provide a summary of current knowledge on the optimum approach to reduce antibiotic pressure in late-onset sepsis in neonates. Full article