Nucleotide receptors mediate protection against neonatal sepsis and meningitis caused by alpha-hemolysin expressing Escherichia coli K1.

Neonatal meningitis-associated Escherichia coli (NMEC) is among the leading causes of bacterial meningitis and sepsis in newborn infants. Several virulence factors have been identified as common among NMEC, and have been shown to play an important role in the development of bacteremia and/or meningitis. However, there is significant variability in virulence factor expression between NMEC isolates, and relatively little research has been done to assess the impact of variable virulence factor expression on immune cell activation and the outcome of infection. Here, we investigated the role of NMEC strain-dependent P2X receptor (P2XR) signaling on the outcome of infection in neonatal mice. We found that alpha-hemolysin (HlyA)-expressing NMEC (HlyA+ ) induced robust P2XR-dependent macrophage cell death in vitro, while HlyA- NMEC did not. P2XR-dependent cell death was inflammasome independent, suggesting an uncoupling of P2XR and inflammasome activation in the context of NMEC infection. In vivo inhibition of P2XRs was associated with increased mortality in neonatal mice infected with HlyA+ NMEC, but had no effect on the survival of neonatal mice infected with HlyA- NMEC. Furthermore, we found that P2XR-dependent protection against HlyA+ NMEC in vivo required macrophages, but not neutrophils or NLRP3. Taken together, these data suggest that HlyA+ NMEC activates P2XRs which in turn confers macrophage-dependent protection against infection in neonates. In addition, our findings indicate that strain-dependent virulence factor expression should be taken into account when studying the immune response to NMEC.

Whole-genome sequencing-based phylogeny, antibiotic resistance, and invasive phenotype of Escherichia coli strains colonizing the cervix of women in preterm labor.

BACKGROUND: Escherichia coli is a major neonatal pathogen and the leading cause of early-onset sepsis in preterm newborns. Maternal E. coli strains are transmitted to the newborn causing invasive neonatal disease. However, there is a lack of data regarding the phenotypic and genotypic characterization of E. coli strains colonizing pregnant women during labor. METHODS: This prospective study performed at the University of Oklahoma Medical Center (OUHSC) from March 2014 to December 2015, aimed to investigate the colonization rate, and the phylogeny, antibiotic resistance traits, and invasive properties of E. coli strains colonizing the cervix of fifty pregnant women diagnosed with preterm labor (PTL). Molecular analyses including bacterial whole-genome sequencing (WGS), were performed to examine phylogenetic relationships among the colonizing strains and compare them with WGS data of representative invasive neonatal E. coli isolates. Phenotypic and genotypic antibiotic resistance traits were investigated. The bacteria's ability to invade epithelial cells in vitro was determined. RESULTS: We recruited fifty women in PTL. Cervical samples yielded E. coli in 12 % (n=6). The mean gestational age was 32.5 (SD±3.19) weeks. None delivered an infant with E. coli disease. Phenotypic and genotypic antibiotic resistance testing did not overall demonstrate extensive drug resistance traits among the cervical E. coli isolates, however, one isolate was multi-drug resistant. The isolates belonged to five different phylogroups, and WGS analyses assigned each to individual multi-locus sequence types. Single nucleotide polymorphism-based comparisons of cervical E. coli strains with six representative neonatal E. coli bacteremia isolates demonstrated that only half of the cervical E. coli isolates were phylogenetically related to these neonatal invasive strains. Moreover, WGS comparisons showed that each cervical E. coli isolate had distinct genomic regions that were not shared with neonatal E. coli isolates. Cervical and neonatal E. coli isolates that were most closely related at the phylogenetic level had similar invasion capacity into intestinal epithelial cells. In contrast, phylogenetically dissimilar cervical E. coli strains were the least invasive among all isolates. CONCLUSIONS: This pilot study showed that a minority of women in PTL were colonized in the cervix with E. coli, and colonizing strains were not phylogenetically uniformly representative of E. coli strains that commonly cause invasive disease in newborns. Larger studies are needed to determine the molecular characteristics of E. coli strains colonizing pregnant women associated with an increased risk of neonatal septicemia.

Recurrent neonatal sepsis and progressive white matter injury in a premature newborn culture-positive for group B Streptococcus: A case report.

RATIONALE: Group B Streptococcus (GBS) remains a principal pathogen causing neonatal sepsis and meningitis, particularly in premature infants with relatively insufficient immunity. Recurrence may occur uncommonly, largely associated with subclinical mucosal persistence or repetitive exposure to exogenous sources. White matter injury (WMI) including cystic periventricular leukomalacia (PVL) has been associated with intrauterine infection/inflammation, and neonatal infection as a more significant predictor including postnatal sepsis and recurrent infection, even without microbial neuroinvasion. Furthermore, clinical and experimental evidence of WMI by some bacteria other than GBS without central nervous system invasion has been reported. However, there is little evidence of WMI associated with neonatal GBS sepsis in the absence of meningitis in the literature. PATIENT CONCERNS: A newborn at 30+4 weeks' gestation with low birthweight presented with 2 episodes (with a 13-day interval with no antibiotic therapy) of neonatal sepsis culture-proven for GBS with early-onset presentation after clinical chorioamnionitis via vertical GBS transmission and the associated conditions including prematurity-related neonatal immunodeficiency and persistent mucosal GBS carriage after the first antibiotic treatment. The perinatal GBS infection was complicated by progressive WMI presenting with ventriculomegaly and cystic PVL without a definite evidence of meningitis, intraventricular hemorrhage, and documented cerebral hypoxia or hypoperfusion conditions including septic shock. DIAGNOSES: Recurrent group B streptococcal sepsis and cystic PVL with ventriculomegaly. INTERVENTIONS: Two episodes of GBS sepsis were treated with 15-day parenteral antibiotic therapy, respectively. OUTCOMES: Resolution of the recurrent GBS sepsis without further relapses, however, complicated by WMI and subsequent about 6 months delay in motor development at 12 months' corrected age. LESSONS: This case suggests WMI associated with GBS bacteremia without central nervous system entry by viable GBS and also shows that in premature infants, intrauterine GBS infection with no interventions may lead to extensive and persistent GBS colonization, early-onset and recurrent GBS disease, and WMI. Postnatal as well as intrauterine infection/inflammation controls with maternal prophylaxis may be pivotal for prevention and limiting the magnitude of neurologic injury.

Survival and Pulmonary Injury After Neonatal Sepsis: PD1/PDL1's Contributions to Mouse and Human Immunopathology.

Morbidity and mortality associated with neonatal sepsis remains a healthcare crisis. PD1-/- neonatal mice endured experimental sepsis, in the form of cecal slurry (CS), and showed improved rates of survival compared to wildtype (WT) counterparts. End-organ injury, particularly of the lung, contributes to the devastation set forth by neonatal sepsis. PDL1-/- neonatal mice, in contrast to PD1-/- neonatal mice did not have a significant improvement in survival after CS. Because of this, we focused subsequent studies on the impact of PD1 gene deficiency on lung injury. Here, we observed that at 24 h post-CS (but not at 4 or 12 h) there was a marked increase in pulmonary edema (PE), neutrophil influx, myeloperoxidase (MPO) levels, and cytokine expression sham (Sh) WT mice. Regarding pulmonary endothelial cell (EC) adhesion molecule expression, we observed that Zona occludens-1 (ZO-1) within the cell shifted from a membranous location to a peri-nuclear location after CS in WT murine cultured ECs at 24hrs, but remained membranous among PD1-/- lungs. To expand the scope of this inquiry, we investigated human neonatal lung tissue. We observed that the lungs of human newborns exposed to intrauterine infection had significantly higher numbers of PD1+ cells compared to specimens who died from non-infectious causes. Together, these data suggest that PD1/PDL1, a pathway typically thought to govern adaptive immune processes in adult animals, can modulate the largely innate neonatal pulmonary immune response to experimental septic insult. The potential future significance of this area of study includes that PD1/PDL1 checkpoint proteins may be viable therapeutic targets in the septic neonate.

A Novel Surface-Exposed Polypeptide Is Successfully Employed as a Target for Developing a Prototype One-Step Immunochromatographic Strip for Specific and Sensitive Direct Detection of Staphylococcus aureus Causing Neonatal Sepsis.

Neonatal sepsis is a life-threatening condition and Staphylococcus aureus is one of its major causes. However, to date, no rapid and sensitive diagnostic tool has been developed for its direct detection. Bioinformatics analyses identified a surface-exposed 112-amino acid polypeptide of the cell wall protein NWMN_1649, a surface protein involved in cell aggregation and biofilm formation, as being a species-specific and highly conserved moiety. The polypeptide was cloned, purified, and used to immunize mice to raise specific immunoglobulins. The purified antibodies were conjugated to gold nano-particles and used to assemble an immunochromatographic strip (ICS). The developed prototype ICS detected as low as 5 µg purified polypeptide and 102 CFU/mL S. aureus within 15 min. The strip showed superior ability to directly detect S. aureus in neonatal sepsis blood specimens without prior sample processing. Moreover, it showed no cross-reaction in specimens infected with two other major causes of neonatal sepsis; coagulase-negative staphylococci and Klebsiella pneumoniae. The selected NWMN_1649-derived polypeptide demonstrates success as a promising biomolecule upon which a prototype ICS has been developed. This ICS provides a rapid, direct, sensitive, and specific option for the detection of S. aureus causing neonatal sepsis. Such a tool is urgently needed especially in resources-limited countries.

Differences in clinical characteristics of early- and late-onset neonatal sepsis caused by Klebsiella pneumoniae.

To identify differences in the clinical characteristics of early- and late-onset sepsis (EOS and LOS) caused by Klebsiella pneumoniae (K. pneumoniae) and to describe the risk factors for multidrug-resistant K. pneumoniae (MDR-KP) infection. Infants with K. pneumoniae-induced sepsis who were admitted to a children's Hospital between Jan 2000 and Dec 2019 were included. All infants were divided into EOS and LOS groups, as well as MDR-KP and non-MDR-KP groups. Demographics, clinical characteristics, and risk factors were compared between the two groups. One hundred eighty infants (66 with EOS and 114 with LOS) were further analyzed, accounting for 36.8% of sepsis cases caused by MDR-KP. The frequency of respiratory failure, bronchopulmonary dysplasia, and intraventricular hemorrhage were more common in the LOS group and a higher rate of acute respiratory distress syndrome was more common in infants in the EOS group (P < 0.05). K. pneumoniae showed a low sensitivity to penicillin, beta-lactams and cephalosporins, and it showed a high sensitivity to levofloxacin, ciprofloxacin, and amikacin. Prematurity, low birth weight, longer antibiotic exposure time, long duration of peripheral catheter insertion, long mechanical ventilation time, and long parenteral nutrition time were associated with an increased rate of MDR-KP infection by univariate analysis (P < 0.05). The regression analysis identified a long antibiotic exposure time (OR = 1.37, 95% CI: 1.01-1.89) and long parenteral nutrition time (OR = 1.39, 95% CI: 1.01-1.89) as independent risk factors for a MDR-KP infection, and a greater gestational age and birth weight were associated with a lower risk of MDR-KP infection (OR = 0.57, 95% CI: 0.40-0.79). LOS caused by K. pneumoniae may lead to a higher frequency of complications. The risk factors for MDR-KP infection were longer duration of antibiotic exposure and parenteral nutrition. A greater gestational age and larger birth weight may decrease the risk of MDR-KP infection.

Group B streptococcal transmission rates as determined by PCR.

Background Group B Streptococcus (GBS) is a common cause of neonatal sepsis. GBS colonization of the newborn gastrointestinal tract (GIT) may be a critical precursor for late-onset infection. Assessment of the rate of neonatal GBS intestinal colonization has generally relied upon culture-based methods. We used polymerase chain reaction (PCR) and culture to determine the rate of GBS transmission to neonates. We hypothesized that PCR may enhance the detection of neonatal GBS colonization of the GIT, and that the rate will be higher when evaluated with PCR as compared to culture. Methods This was a cross-sectional study, in which mothers who were positive for GBS on routine screening and their healthy infants were eligible for recruitment. Newborn stool was collected after 24 h of life and before hospital discharge, and stored at -80°C for culture and PCR targeting the GBS-specific surface immunogenic protein (sip) gene. Results A total of 94 mother-infant pairs were enrolled; of these pairs, stool was collected from 83 infants. Based on PCR, the overall GBS transmission rate was 3.6% (3/83). The transmission rate was 2.4% (1/41) among vaginal deliveries and 4.8% (2/42) among cesarean deliveries. The results of culture-based transmission detection were identical. Conclusion These results indicate that the rate of GBS transmission is low and that detection may not be enhanced by PCR methods.

The Neonatal Early Onset Sepsis Calculator; in Clinical Practice.

Aims To determine the impact of applying the Neonatal Early Onset Sepsis Calculator (NEOSC) to clinical practice. We evaluated this multivariable risk prediction model, used in the assessment of infants >35 weeks GA, at risk of neonatal sepsis. Methods A retrospective, cohort study comparing the rates of blood culture use in a large maternity hospital before and after the introduction of the NEOSC. Cases were ascertained from the records of the Department of Microbiology. The key variables were the number of blood cultures (all gestational ages, <72 hours old), infant antibiotic use and sepsis rates. Data for three years prior to NEOSC use (January 2015 - December 2017) were compared with 15 months (January 2018 - Q1 2019) after it was implemented. Results Pre- and post- NEOSC use, the total blood cultures taken annually were: 1,312 (2015), 1,149 (2016), 1,319 (2017) and 702 (2018), 192 (Q1 2019) respectively, a statistically significant reduction [p < 0.00001, 95% CI]. There was no significant difference in rates of either: culture-confirmed GBS-sepsis [p value 0.18, 95% CI] or other-pathogen sepsis [p value 0.32, 95%CI] in term infants between the two periods. There was a significant reduction in antibiotic use in the first 24 hours of life (average 11.3% pre-NEOSC and 5.9% after NEOSC was implemented) [p < 0.00001, 95% CI]. Conclusion The introduction of the NEOSC has reduced blood culture and antibiotic use. This has been achieved without any increase in infection rates.

Maternal activation of the EGFR prevents translocation of gut-residing pathogenic Escherichia coli in a model of late-onset neonatal sepsis.

Late-onset sepsis (LOS) is a highly consequential complication of preterm birth and is defined by a positive blood culture obtained after 72 h of age. The causative bacteria can be found in patients' intestinal tracts days before dissemination, and cohort studies suggest reduced LOS risk in breastfed preterm infants through unknown mechanisms. Reduced concentrations of epidermal growth factor (EGF) of maternal origin within the intestinal tract of mice correlated to the translocation of a gut-resident human pathogen Escherichia coli, which spreads systemically and caused a rapid, fatal disease in pups. Translocation of Escherichia coli was associated with the formation of colonic goblet cell-associated antigen passages (GAPs), which translocate enteric bacteria across the intestinal epithelium. Thus, maternally derived EGF, and potentially other EGFR ligands, prevents dissemination of a gut-resident pathogen by inhibiting goblet cell-mediated bacterial translocation. Through manipulation of maternally derived EGF and alteration of the earliest gut defenses, we have developed an animal model of pathogen dissemination which recapitulates gut-origin neonatal LOS.

A novel method to detect bacterial infection in premature infants: Using a combination of inflammatory markers in blood and saliva.

BACKGROUND: Opportunistic infection leads to high morbidity and mortality in premature babies due to their immature immune system. Biomarkers in blood have been reported to detect bacterial infection in neonates. However, serial blood exams pose iatrogenic anemia in premature babies. Thus, this study aimed to identify cytokines in saliva, which can help to diagnose bacterial infection in premature babies via a non-invasive method. METHODS: Premature neonates were enrolled from Aug. 2012 to Feb. 2015 after completing informed consent. Babies with congenital anomalies, bronchopulmonary dysplasia, necrotizing enterocolitis and any surgical indicated diseases were excluded. Salivary samples collection and septic work-up were performed when bacterial infection was clinically suspected, as well as one week after antimicrobial treatment. The level of salivary cytokines was detected by MILLPLEX® MAP and analyzed by Mann-Whitney U test. RESULTS: There were 16 episodes of bacterial infection in 10 cases. Culture-positive group had significantly higher levels of salivary Interleukin (IL) 6, IL-8, macrophage inflammatory protein (MIP)1α, MIP-1ß and tumor necrosis factor (TNF)-α than that in the culture-negative group (p = 0.002, 0.006, 0.001, <0.001, 0.009), and blood C-reactive protein and sugar as well (p < 0.001, 0.026). After adjusting postmenstrual age by logistic regression, blood sugar level was the most significant biomarker (p = 0.019). In combination of blood and salivary biomarkers, blood sugar higher than 67 mg/dL and salivary IL-6 higher than 367.25 pg/mL concurrently, would accurately detect bacterial infection in premature babies. CONCLUSION: This non-invasive method might help us to accurately diagnose bacterial infection in premature babies.

Presepsin and fetuin-A dyad for the diagnosis of proven sepsis in preterm neonates.

BACKGROUND: Diagnosis is the most strenuous step in the evaluation of neonatal sepsis. No gold standard diagnostic method is available except for blood culture. We aimed to investigate the role of positive and negative acute phase reactants, namely presepsin and fetuin-A, in the diagnosis of culture-proven late-onset sepsis. METHODS: A prospective, case-control study with the infants ≤32 weeks of age with a diagnosis of culture-proven late-onset sepsis was designed. Twenty-nine preterm infants with similar gestational and postnatal ages without sepsis constituted the control group. Serum values of presepsin, fetuin-A, C-reactive protein and interleukin-6 were evaluated at the enrollment, third and seventh days of the diagnosis in the infants with positive blood culture results. RESULTS: First-day presepsin values were significantly higher in the culture-positive infants than the control group [1583 ng/L (1023-1731) vs. 426 ng/L (287-589), p = < 0.0001]. Presepsin was found to have an 88.9% sensitivity and 88.9% specificity with a cut-off value of 823 ng/ml for culture-proven LOS in our study, and area under the receiver-operating curve was 0.939. Fetuin-A levels were similar between the study and control groups (p > 0.05). CONCLUSION: Presepsin may be an accurate marker for both diagnosis and monitoring of treatment response for culture-proven late-onset sepsis in preterm infants. However, fetuin-A does not seem to be a useful tool for the diagnosis of sepsis.

Prevalencia de β -lactamasas de espectro extendido en enterobacterias causantes de sepsis neonatal y factores asociados / Prevalence of extended-spectrum beta-lactamases in enterobacteria of neonatal sepsis and associated factors

Resumen Introducción: Las infecciones causadas por enterobacterias productoras de β-talactamasas de espectro extendido (EP-BLEE) tienen implicaciones sobre la morbilidad y mortalidad neonatal. Objetivo: Describir la prevalencia de EP-BLEE en sepsis neonatal y los factores asociados. Métodos: Estudio de cohorte prospectivo, desde agosto del 2016 a agosto del 2017. Se incluyeron recién nacidos (RNs) ingresados en el Hospital Civil de Guadalajara "Dr. Juan I. Menchaca". Mediante prueba de difusión de doble disco se indagó la presencia de EP-BLEE y su asociación con características clínicas y demográficas de los RNs. Resultados: Se estudiaron 1.501 RNs hospitalizados, con edad gestacional promedio de 36,3 semanas. Se diagnosticaron 196 eventos de sepsis neonatal, la etiología más frecuente fueron enterobacterias (45,5%); 88,8% demostraron resistencia a ampicilina y más de 42% a cefalosporinas de amplio espectro. El 22,9% presentó fenotipo BLEE positivo. Tener Apgar ≤ 7 a los cinco minutos de vida (OR 4,6; IC 95% 1,47-14,6) y edad gestacional < 37 semanas (OR 5,4; IC 95%1,04-27,7) incrementaron el riesgo. Conclusión: En las enterobacterias causantes de sepsis neonatal, 22,9% son EP-BLEE; la infección es más probable en pacientes con Apgar ≤ 7 a los cinco minutos de vida y en prematuros.

Background: Infections caused by extended-spectrum beta-lactamases enterobacteria (ESBL-EP) have implications for neonatal morbidity and mortality. Aim: To describe the prevalence of ESBL-EP in neonatal sepsis and associated factors. Methods: A prospective cohort study was conducted from August 2016 to August 2017; newborn babies (NB) hospitalized in the Hospital Civil de Guadalajara "Dr. Juan I. Menchaca" were included. The ESBL-EP were investigated by double-disk synergy test and its association with clinical and demographic characteristics of the NB. Results. A total of 1,501 hospitalized NB were studied, with an average gestational age of 36.3 weeks. They were diagnosed 196 neonatal sepsis events, the most frequent etiologies were enterobacteria (45.5%). Resistance to ampicilin was found in 88.8% and to broad spectrum cephalosporins in more than 42% of the strains; 22.9% of them were ESBL phenotype. Apgar ≤ 7 at five minutes of life (OR 4.6; 95% CI 1.47-14.6) and gestational age < 37 weeks (OR 5.4; 95% CI 1.04-27.) increase the risk. Conclusion: In enterobacteria that cause neonatal sepsis, 22.9% were EP-ESBL; infection was more likely in patients with Apgar ≤ 7 at five minutes of age and in preterm infants.

Cord blood procalcitonin level and early-onset sepsis in extremely preterm infants.

Early-onset neonatal sepsis (EOS) is observed in 1.7% of extremely preterm infants, with high morbidity and mortality rate. Cord blood procalcitonin (PCT) is a sensitive marker of EOS in full-term newborns, but it has been rarely studied in premature infants. The diagnostic value of cord blood PCT by immunofluorescence has been assessed as an early marker of EOS in a prospective cohort of extremely preterm infants, with a threshold at 0.5 µg/L. EOS was defined by a positive bacterial culture or by the association of postnatal biological/clinical signs of EOS and antibiotic treatment for more than 72 h. Correlation between PCT serum concentrations and postnatal morbidities was also analyzed. Among a total of 186 infants, 45 (24%) were classified as EOS. Blood PCT concentration was ≤ 0.5 µg/L in 114 infants, including 11 EOS (9.6%) and PCT was > 0.5 µg/L in 72 babies including 34 EOS (47.2%). PCT concentration > 0.5 µg/L was associated with higher risk of EOS (OR 2.18; CI95% 1.58-3.02; p < 0.0001). The receiver operating characteristic curve determined a cutoff of 0.7 µg/L as the best compromise, with an area under the curve of 0.75 (sensitivity 69%, specificity 70%). In multivariate analysis, clinical chorioamnionitis was associated with PCT concentration > 0.5 µg/L (OR 2.58; CI95% 1.35-4.94; p = 0.004). Cord blood PCT is a marker significantly associated with EOS in extremely preterm infants, but its sensitivity remains low. Its added value in combination with other early marker of EOS needs to be further investigated in this high-risk population.

A Comparative Evaluation of Presepsin with Procalcitonin and CRP in Diagnosing Neonatal Sepsis.

The objectives of this study were to study the clinical and biochemical profile of neonates with sepsis and to evaluate the diagnostic role of presepsin and its comparison with C-reactive protein (CRP) and Procalcitonin (PCT). This study was conducted from March 2015 through October 2016 in Neonatal intensive care unit (NICU) at S N Medical College, Agra. Neonates with ≥1 clinical features of sepsis and/or two risk factors were included. A total of 41 cases and 41 controls were taken. Blood sample was taken for all investigations. ROC curve analysis was performed. Out of 41 cases, 19 were blood culture positive, majority were males (68.3%), low birth weight (LBW: 70.7%) and preterms (53.6%). At chosen cut-off values, sensitivity of CRP, PCT and presepsin was 80.5%, 80.5%, 97.6% and specificity was 97.5%, 80.5%, 95.1% respectively. PCT and CRP were comparable as diagnostic markers of neonatal sepsis. Presepsin, in comparison with CRP and PCT has better sensitivity and negative predictive value (NPV).

Síndrome celulitis-adenitis, una forma infrecuente de presentación de la sepsis neonatal tardía: A propósito de dos casos / Adenitis-cellulitis syndrome, an infrequent form of presentation of the late-onset neonatal septicemia: Report of two cases

La sepsis es la principal causa de mortalidad neonatal. La forma precoz, habitualmente, está relacionada con la colonización recto-vaginal u otros factores de riesgo materno. En la forma tardía, es difícil establecer su origen; por lo general, es nosocomial o de la comunidad. El Streptococcus agalactiae (Streptococcus beta-hemolítico del grupo B) es el germen implicado con más frecuencia en la sepsis neonatal en países desarrollados. La forma tardía, generalmente, se presenta con septicemia y meningitis, y, en ocasiones, pueden detectarse infecciones osteoarticulares o de piel y tejidos blandos. El síndrome celulitis-adenitis en la región cervical, forma poco frecuente de presentación, es causado por Staphylococcus aureus y, ocasionalmente, por Streptococcus agalactiae. Se reportan 2 casos de sepsis neonatal tardía con clínica de celulitis-adenitis cervical causados por Streptococcus beta-hemolítico del grupo B, con una evolución satisfactoria con terapia antibiótica de amplio espectro.

Septicemia is the main cause of neonatal mortality. The early-onset neonatal sepsis is usually related to maternal factor risks including recto-vaginal colonization. In the late-onset neonatal septicemia it is more difficult to establish the etiology because the majority of the cases are nosocomial or community related. The Streptococcus agalactiae (beta-hemolytic Streptococcus) is the most frequent germ associated with neonatal sepsis in developed countries. The late-onset form usually occurs with septic symptoms and meningitis and, in a few cases, with osteoarticular, skin and soft tissue infection. Adenitis-cellulitis syndrome is rarely seen, and its main cause is Staphylococcus aureus, followed by Streptococcus agalactiae. We report two cases of group B Streptococcus late-onset neonatal septicemia, both of them with adenitis-cellulitis syndrome. Patients recovered uneventfully after an adequate antibiotic therapy.

Pentoxifylline Alone or in Combination with Gentamicin or Vancomycin Inhibits Live Microbe-Induced Proinflammatory Cytokine Production in Human Cord Blood and Cord Blood Monocytes In Vitro.

Neonatal sepsis and its accompanying inflammatory response contribute to substantial morbidity and mortality. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses transcription and production of proinflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that PTX decreases live microbe-induced inflammatory cytokine production in newborn blood. Cord blood was stimulated with live microorganisms commonly encountered in newborn sepsis (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, or Candida albicans) and simultaneously treated with antimicrobial agents (gentamicin, vancomycin, or amphotericin B) and/or clinically relevant concentrations of PTX. Microbial colony counts were enumerated by plating, supernatant cytokines were measured by multiplex assay, intracellular cytokines and signaling molecules were measured by flow cytometry, and mRNA levels were measured by quantitative reverse transcription-PCR. PTX inhibited concentration-dependent E. coli-, S. aureus-, S. epidermidis-, and C. albicans-induced tumor necrosis factor (TNF) and E. coli-induced interleukin-1ß (IL-1ß) production in whole blood, with greater suppression of proinflammatory cytokines in combination with antimicrobial agents. Likewise, PTX suppressed E. coli-induced monocytic TNF and IL-1ß, whereby combined PTX and gentamicin led to significantly greater reduction of TNF and IL-1ß. The anti-inflammatory effect of PTX on microbe-induced proinflammatory cytokine production was accompanied by inhibition of TNF mRNA expression and was achieved without suppressing the production of the anti-inflammatory IL-10. Of note, microbial colony counts in newborn blood were not increased by PTX. Our findings demonstrated that PTX inhibited microbe-induced proinflammatory cytokine production, especially when combined with antimicrobial agents, without enhancing microbial proliferation in human cord blood in vitro, thus supporting its utility as candidate adjunctive agent for newborn sepsis.

Selective or universal screening for GBS in pregnancy (review).

Group B streptococcus (GBS) is the most common cause of early-onset neonatal sepsis in many countries and responsible for significant perinatal morbidity and mortality worldwide. Intrapartum antibiotic prophylaxis has been the mainstay of efforts to prevent early-onset GBS disease in recent decades, however it is unclear if women should be targeted based on the presence of clinical risk factors or by screening for GBS colonisation during pregnancy. Universal bacteriological screening of women in late pregnancy has been widely adopted but questions remain regarding its benefits and potential harms. Newer approaches to screening based on rapid point-of-care testing require further evaluation in randomised controlled trials to inform evidence-based practice. Given current preventive strategies do not protect against late onset disease and other sequelae of infection, maternal vaccination against GBS may present the best opportunity to reduce the global burden of invasive GBS disease in the future.

Inadequate use of antibiotics and increase in neonatal sepsis caused by resistant bacteria related to health care assistance: a systematic review

ABSTRACT Background Technologies and life support management have enhanced the survival of preterm infants. The immune system of newborns is immature, which contributes to the occurrence of healthcare-associated infections. The overlap of several conditions with neonatal sepsis and the difficulty of diagnosis and laboratory confirmation during this period result in a tendency to over-treat neonatal sepsis. The use of antimicrobial agents is a risk factor for multidrug-resistant bacterial infections. This work aimed to perform a systematic review of the relationship between inadequate use of antimicrobial agents and increase in neonatal sepsis related to healthcare assistance, due to bacterial resistance. Methods Our population, exposition, comparison, outcome and study type was as follows: P: hospitalized neonates with sepsis diagnosis, E: inappropriate use of antimicrobial agents, C: adequate use of antimicrobial agents or no indication of infection, O: resistant bacterial infection, and S: original studies. We performed searches in the PubMed, Scopus, Virtual Health Library (Scielo, LILACS, and MEDLINE), and Embase without limits on time, language, and the references of the articles found. Fourteen studies were included and assessed using the Grading of Recommendations, Assessment, Development, and Evaluation, Newcastle, and the Strengthening the Reporting of Observacional Studies in Epidemiology methodologies. Results All studies found were observational and started with a low-quality evidence level in the Grading of Recommendations, Assessment, Development, and Evaluation. Conclusions Despite their low-quality evidence, the studies demonstrated the association between inadequate use of antimicrobial agents and increase of neonatal resistant bacterial healthcare-associated infections in neonatal units. However, there is significant difficulty in conducting high-quality studies in this population due to ethical issues tied to randomized trials. Therefore, new studies should be encouraged to recommend adequate treatment of newborns without increasing the risk of healthcare-associated infections by multidrug-resistant bacteria.