16S rDNA Sequencing for Bacterial Identification in Preterm Infants with Suspected Early-Onset Neonatal Sepsis.

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.

Improved efficiency in the management of newborns with infectious risk factors by the sepsis risk calculator and clinical observation.

OBJECTIVE: To evaluate the efficiency of the sepsis risk calculator and the serial clinical observation in the management of late preterm and term newborns with infectious risk factors. METHOD: Single-center, observational, two-phase cohort study comparing the rates of neonates born ≥35 weeks' gestation, ≥2000 g birthweight, and without major congenital anomalies, who were screened and/or received antibiotics for early-onset neonatal sepsis risk at our center during two periods, before (January/2018-June/2019) and after (July/2019-December/2020) the implementation of the sepsis risk calculator. RESULTS: A total of 1796 (Period 1) and 1867 (Period 2) patients with infectious risk factors were included. During the second period, tests to rule out sepsis were reduced by 34.0 % (RR, 95 %CI): 0.66 (0.61, 0.71), blood cultures by 13.1 %: 0.87 (0.77, 0.98), hospital admissions by 13.5 %: 0.86 (0.76, 0.98) and antibiotic administration by 45.9 %: 0.54 (0.47, 0.63). Three cases of early-onset neonatal sepsis occurred in the first period and two in the second. Clinical serial evaluation would have detected all true cases. CONCLUSIONS: The implementation of a sepsis risk calculator in the management of newborns ≥35 weeks GA, ≥2000 g birthweight, without major congenital anomalies, with infectious risk factors is safe and adequate to reduce laboratory tests, blood cultures, hospital admissions, and antibiotics administration. Serial clinical observation, in addition, could be instrumental to achieve or even improve this goal.

Improved efficiency in the management of newborns with infectious risk factors by the sepsis risk calculator and clinical observation

Abstract Objective To evaluate the efficiency of the sepsis risk calculator and the serial clinical observation in the management of late preterm and term newborns with infectious risk factors. Method Single-center, observational, two-phase cohort study comparing the rates of neonates born ≥35 weeks' gestation, ≥2000 g birthweight, and without major congenital anomalies, who were screened and/or received antibiotics for early-onset neonatal sepsis risk at our center during two periods, before (January/2018-June/2019) and after (July/2019-December/2020) the implementation of the sepsis risk calculator. Results A total of 1796 (Period 1) and 1867 (Period 2) patients with infectious risk factors were included. During the second period, tests to rule out sepsis were reduced by 34.0 % (RR, 95 %CI): 0.66 (0.61, 0.71), blood cultures by 13.1 %: 0.87 (0.77, 0.98), hospital admissions by 13.5 %: 0.86 (0.76, 0.98) and antibiotic administration by 45.9 %: 0.54 (0.47, 0.63). Three cases of early-onset neonatal sepsis occurred in the first period and two in the second. Clinical serial evaluation would have detected all true cases. Conclusions The implementation of a sepsis risk calculator in the management of newborns ≥35 weeks GA, ≥2000 g birthweight, without major congenital anomalies, with infectious risk factors is safe and adequate to reduce laboratory tests, blood cultures, hospital admissions, and antibiotics administration. Serial clinical observation, in addition, could be instrumental to achieve or even improve this goal.

Prevalencia de sepsis neonatal confirmada microbiológicamente en una maternidad de la Ciudad Autó noma de Buenos Aires / Prevalence of microbiologically confirmed neonatal sepsis at a maternity center in the City of Buenos Aires

Introducción. En neonatos internados es frecuente sospechar sepsis neonatal, pero solo en el 25 % al 30 % se confirma con cultivos positivos. La selección del esquema antibiótico basándose en la epidemiología local favorece el uso racional y minimiza sus efectos colaterales. Objetivo primario. Describir la prevalencia de sepsis precoz y tardía con rescate microbiológico y sus características clínicas. Población y método. Estudio transversal retrospectivo, realizado del 1 de enero de 2013 al 31 de diciembre de 2017, en una maternidad pública de Argentina, que incluyó todos los recién nacidos internados en la unidad con diagnóstico de sepsis precoz y tardía con rescate microbiológico, y aquellos reingresados dentro del mes de vida. Resultados. Ingresaron 3322 recién nacidos, 1296 evaluados por sospecha de sepsis precoz, cultivos positivos en 25 (1,9 %; tasa: 0,86 ‰). El 52 % eran menores de 33 semanas de edad gestacional. Microorganismos: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Sepsis tardía (tasa 8,73 ‰), el 68 % ocurridas en menores de 33 semanas. Microorganismos intrahospitalarios: Staphylococcus coagulasa negativos 115, Staphylococcus aureus 47, Escherichia coli 30, Cándida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11 y Streptococcus agalactiae 10. En los reingresos: E. coli 11, S. aureus 12, SGB 3 y Haemophilus influenzae 3. Conclusiones. Se observa en el período estudiado una frecuencia de sepsis precoz similar a los reportes internacionales, con predominio de E. coli y L. monocytogenes. La tasa de sepsis tardía presentó una tendencia descendente en los años analizados, con predominio de los cocos grampositivos

Introduction. Neonatal sepsis is often suspected in hospitalized newborn infants, but only in 25­30% of cases it is confirmed via a positive culture. Selecting the antibiotics based on local epidemiology favors their rational use and minimizes their side effects. Primary objective. To describe the prevalence of early- and late-onset sepsis with microorganism isolation and their clinical characteristics. Population and method. Retrospective, cross-sectional study conducted between 01-01-2013 and 12-31-2017 in a public maternity center of Argentina in all hospitalized newborn infants with a diagnosis of early- and late-onset sepsis with microorganism isolation, and those re-admitted in their first month of life. Results. A total of 3322 newborn infants were admitted; 1296 were assessed for suspected early- onset sepsis; 25 had a positive culture (1.9%; rate: 0.86‰). Of these, 52% were born before 33 weeks of gestation. Microorganisms: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Also, 68% of late-onset sepsis cases (rate: 8.73‰) occurred in infants born before 33 weeks of gestation. Hospital-acquired microorganisms: coagulase-negative Staphylococcus 115, Staphylococcus aureus 47, Escherichia coli 30, Candida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11, and Streptococcus agalactiae 10. In re-admissions: E. coli 11, S. aureus 12, SGB 3, and Haemophilus influenzae 3. Conclusions. During the study period, the frequency of early-onset sepsis was similar to international reports, with a predominance of E. coli and L. monocytogenes. The rate of late-onset sepsis showed a downward trend in the analyzed years, with a predominance of Gram-positive cocci.

Prevalence of microbiologically confirmed neonatal sepsis at a maternity center in the City of Buenos Aires. / Prevalencia de sepsis neonatal confirmada microbiológicamente en una maternidad de la Ciudad Autónoma de Buenos Aires.

Introduction. Neonatal sepsis is often suspected in hospitalized newborn infants, but only in 25-30% of cases it is confirmed via a positive culture. Selecting the antibiotics based on local epidemiology favors their rational use and minimizes their side effects. Primary objective. To describe the prevalence of early- and late-onset sepsis with microorganism isolation and their clinical characteristics. Population and method. Retrospective, cross-sectional study conducted between 01-01-2013 and 12-31-2017 in a public maternity center of Argentina in all hospitalized newborn infants with a diagnosis of early- and late-onset sepsis with microorganism isolation, and those re-admitted in their first month of life. Results. A total of 3322 newborn infants were admitted; 1296 were assessed for suspected early- onset sepsis; 25 had a positive culture (1.9%; rate: 0.86‰). Of these, 52% were born before 33 weeks of gestation. Microorganisms: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Also, 68% of late-onset sepsis cases (rate: 8.73‰) occurred in infants born before 33 weeks of gestation. Hospital-acquired microorganisms: coagulase-negative Staphylococcus 115, Staphylococcus aureus 47, Escherichia coli 30, Candida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11, and Streptococcus agalactiae 10. In re-admissions: E. coli 11, S. aureus 12, SGB 3, and Haemophilus influenzae 3. Conclusions. During the study period, the frequency of early-onset sepsis was similar to international reports, with a predominance of E. coli and L. monocytogenes. The rate of late-onset sepsis showed a downward trend in the analyzed years, with a predominance of Gram-positive cocci.

Introducción. En neonatos internados es frecuente sospechar sepsis neonatal, pero solo en el 25 % al 30 % se confirma con cultivos positivos. La selección del esquema antibiótico basándose en la epidemiología local favorece el uso racional y minimiza sus efectos colaterales. Objetivo primario. Describir la prevalencia de sepsis precoz y tardía con rescate microbiológico y sus características clínicas. Población y método. Estudio transversal retrospectivo, realizado del 1 de enero de 2013 al 31 de diciembre de 2017, en una maternidad pública de Argentina, que incluyó todos los recién nacidos internados en la unidad con diagnóstico de sepsis precoz y tardía con rescate microbiológico, y aquellos reingresados dentro del mes de vida. Resultados. Ingresaron 3322 recién nacidos, 1296 evaluados por sospecha de sepsis precoz, cultivos positivos en 25 (1,9 %; tasa: 0,86 ‰). El 52 % eran menores de 33 semanas de edad gestacional. Microorganismos: Escherichia coli 5, Listeria monocytogenes 4, Streptococcus agalactiae (SGB) 3, Streptococcus pneumoniae 3. Sepsis tardía (tasa 8,73 ‰), el 68 % ocurridas en menores de 33 semanas. Microorganismos intrahospitalarios: Staphylococcus coagulasa negativos 115, Staphylococcus aureus 47, Escherichia coli 30, Cándida spp. 16, Enterococcus faecalis 13, Klebsiella pneumoniae 11 y Streptococcus agalactiae 10. En los reingresos: E. coli 11, S. aureus 12, SGB 3 y Haemophilus influenzae 3. Conclusiones. Se observa en el período estudiado una frecuencia de sepsis precoz similar a los reportes internacionales, con predominio de E. coli y L. monocytogenes. La tasa de sepsis tardía presentó una tendencia descendente en los años analizados, con predominio de los cocos grampositivos.

Prediction of early-onset neonatal sepsis in umbilical cord blood analysis: an integrative review.

OBJECTIVE: The aim of this study was to describe the inflammatory markers studied in umbilical cord blood and to analyze the performance of the three markers most frequently studied for the prediction of early-onset neonatal sepsis. DATA SOURCES: An integrative review from 1995 to 2021 was performed, with a search in the MEDLINE, Embase, Cochrane Library, SciELO, and gray literature databases, using the terms "neonates," "newborns," "neonatal sepsis," "early-onset neonatal sepsis," "neonatal infection," "inflammatory markers," "biomarkers," "cord blood," "fetal blood." STUDY SELECTION AND DATA EXTRACTIONS: Study evaluation was limited to primary studies, prospective, observational or intervention, descriptive or analytical, that assessed the diagnosis of early-onset neonatal sepsis using inflammatory markers in umbilical cord blood, in Portuguese, English, or Spanish. Qualitative studies, reports, review studies, and case series were excluded. Only studies with a punctuation ≥ 6 in the Newcastle-Ottawa scale were included. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Sixteen studies were included in the qualitative synthesis. Procalcitonin, C-reactive protein, and interleukin-6 were the most frequently studied markers. The best performance for C-reactive protein was observed at a 0.2 mg/L cutoff, with a sensitivity of 82% and a negative predictive value of 99%. Procalcitonin presented the best performance at a 0.5 ng/mL cutoff with 87.5% sensitivity and 98.7% negative predictive value. Interleukin-6 presented the best performance at a 108.5 ng/mL cutoff, with 95% sensitivity and 97.4% negative predictive value. CONCLUSION: The evaluation of markers in the umbilical cord for the diagnosis of early-onset neonatal sepsis, could contribute to a more assertive therapy for the neonate and anticipate sepsis screening. Since the cost is less and technically easier, C-reactive protein is recommended for routine use.

Meconium microbiota predicts clinical early-onset neonatal sepsis in preterm neonates.

BACKGROUND: Early-onset neonatal sepsis (EONS) remains one of the leading causes of morbidity and mortality related to premature birth, and its diagnosis remains difficult. Our goal was to evaluate the intestinal microbiota of the first meconium of preterm newborns and ascertain whether it is associated with clinical EONS. METHODS: In a controlled, prospective cohort study, samples of the first meconium of premature infants with a gestational age (GA) ≤32 weeks was obtained at Hospital de Clínicas de Porto Alegre and DNA was isolated from the samples. 16S rDNA based microbiota composition of preterm infants with a clinical diagnosis of EONS was compared to that of a control group. RESULTS: 40 (48%) premature infants with clinical diagnosis of EONS and 44 (52%) without EONS were included in the analysis. The most abundant phylum detected in both groups, Proteobacteria, was more prevalent in the sepsis group (p = .034). 14% of variance among bacterial communities (p = .001) correlated with EONS. The genera most strongly associated with EONS were Paenibacillus, Caulobacter, Dialister, Akkermansia, Phenylobacterium, Propionibacterium, Ruminococcus, Bradyrhizobium, and Alloprevotella. A single genus, Flavobacterium, was most strongly associated with the control group. CONCLUSION: These findings suggest that the first-meconium microbiota is different in preterm neonates with and without clinical EONS.

Utilidad de la proteína C-reactiva en la sepsis neonatal temprana / Utility of C-reactive protein in early neonatal sepsis

INTRODUCCIÓN: La baja sensibilidad y especificidad de las ayudas diagnósticas y el bajo aislamiento en los cultivos dificulta el reconocimiento de la sepsis bacteriana de inicio temprano en neonatos. OBJETIVO: Determinar la validez diagnóstica de la de la proteína C reactiva (PCR) en la sepsis en la sepsis neonatal temprana. MÉTODO: Se evaluó el papel de la PCR en el diagnóstico de sepsis neonatal temprana. Las concentraciones se midieron a las 12 y 48 h de vida en pacientes con sospecha de sepsis. Al evaluar la sensibilidad y especificidad de la PCR, se utilizó el resultado de manera cuantitativa y mediante una curva ROC no paramétrica se estimó sensibilidad y especificidad, razones de verosimilitud y porcentaje de clasificación correcta para cada punto de corte posible. RESULTADOS: El estudio incluyó 198 pacientes. La sensibilidad, especificidad, valor predictor positivo (VPP), valor predictor negativo (VPN), índice de probabilidad positiva e índice de probabilidad negativa de la PCR fue de 72,2 - 82,4 - 45,2 - 93,7 - 4,1 y 0,3, respectivamente con área bajo la curva de 0,78. CONCLUSIONES: La PCR es particularmente útil para descartar una infección. Dos PCR seriadas negativas en ausencia de expresión clínica y de hemocultivos positivos tienen un alto VPN y un índice de probabilidad negativa a favor de excluir la infección con una alta certeza y/o de descontinuar la terapia antibiótica.

BACKGROUND: The low sensitivity and specificity of diagnostic aids and the low isolation in cultures make it difficult to recognize early-onset bacterial sepsis in neonates. AIM: Determine the diagnostic validity of C reactive protein (CRP) in early neonatal sepsis. METHOD: The role of CRP in the diagnosis of early-onset neonatal sepsis was evaluated. Levels were measured at 12 and 48 hours of life in patients with suspected sepsis. When evaluating the sensitivity and specificity of the CRP, the result was used quantitatively, using a non-parametric ROC curve to estimate sensitivity and specificity, likelihood ratios and percentage of correct classification for each possible cut-off point. RESULTS: The study included 198 patients. The sensitivity, specificity, positive predictive value, negative predictive value, positive probability index and negative probability index of CRP, were 72.2 - 82.4 - 45.2 - 93.7 - 4.1, and 0.3, respectively with area under the curve of 0.78. CONCLUSIONS: CRP is particularly useful to rule out infection. Two negative serial CRP in the absence of clinical symptoms and positive blood cultures have a high negative predictive value and a negative probability index in favor of excluding infection with high certainty and/or discontinuing antibiotic therapy.

Riesgo de sepsis neonatal temprana en recién nacidos de madre con corioamnionitis: Estudio de casos y controles / Early-onset neonatal sepsis in newborns to mother with chorioamnionitis: Case-controls study

Introducción: La corioamnionitis es común durante el embarazo y se asocia con diversas complicaciones perinatales; entre los problemas neonatales más frecuentes están: parto pretérmino, sepsis neonatal, enfermedad pulmonar crónica, lesión cerebral secundaria a infección y trastornos del desarrollo neurológico. Es necesario conocer el riesgo de sepsis neonatal temprana en recién nacidos hijos de madres con corioamnionitis, con la intención de plantear estrategias para su prevención y tratamiento. Objetivos: Determinar el grado de asociación entre la corioamnionitis materna y la aparición de sepsis neonatal temprana. Métodos: Se realizó un estudio de casos y controles donde se incluyeron 148 pacientes divididos en dos grupos: grupo I, los casos, hijos de madres con corioamnionitis (n = 74), y grupo II, control, neonatos sin antecedente de corioamnionitis materna (n = 74). Resultados: El grupo de madres con corioamnionitis tuvo menor control prenatal y sus recién nacidos, a pesar de haber recibido antibiótico profiláctico, tuvieron una mayor frecuencia de sepsis y problemas respiratorios. Conclusiones: Los hijos de madres con corioamnionitis tienen un incremento en el riesgo de presentar sepsis neonatal temprana.

Introduction: Chorioamnionitis is common during pregnancy and associated with several perinatal complications, including postpartum infection and sepsis. Among the most frequent neonatal complications associated to chorioamnionitis are: preterm delivery, neonatal sepsis, chronic lung disease, brain injury secondary to infection, and other neurodevelopmental disorders. It is necessary to know what the risk is of early-onset neonatal sepsis in newborns to mothers with chorioamnionitis. Objective: Determine whether maternal chorioamnionitis has an association with early-onset neonatal sepsis. Methods: We performed a case-control study, in which we included 148 patients divided in two groups: group I, cases (n = 74) and group II, controls (n = 74). The sample size was calculated through difference of proportions. Results: The group of mothers with chorioamnionitis had less prenatal care, and their newborns had a larger number of infections and respiratory problems despite the indication of prophylactic antibiotic schemes. Conclusions: Newborn infants to mother with chorioamnionitis have an increased risk of early neonatal sepsis, despite the use of prophylactic antibiotics.

Diagnosis of neonatal group B Streptococcus sepsis by nested-PCR of residual urine samples

Group B streptococcus (GBS) remains the most common cause of early-onset sepsis in newborns. Laboratory gold-standard, broth culture methods are highly specific, but lack sensitivity. The aim of this study was to validate a nested-PCR and to determine whether residue volumes of urine samples obtained by non invasive, non sterile methods could be used to confirm neonatal GBS sepsis. The nested-PCR was performed with primers of the major GBS surface antigen. Unavailability of biological samples to perform life supporting exams, as well as others to elucidate the etiology of infections is a frequent problem concerning newborn patients. Nevertheless, we decided to include cases according to strict criteria: newborns had to present with signs and symptoms compatible with GBS infection; at least one of the following biological samples had to be sent for culture: blood, urine, or cerebrospinal fluid; availability of residue volumes of the samples sent for cultures, or of others collected on the day of hospitalization, prior to antibiotic therapy prescription, to be analyzed by PCR; favorable outcome after GBS empiric treatment. In only one newborn GBS infection was confirmed by cultures, while infection was only presumptive in the other three patients (they fulfilled inclusion criteria but were GBS-culture negative). From a total of 12 biological samples (5 blood, 3 CSF and 4 urine specimen), eight were tested by culture methods (2/8 were positive), and 8 were tested by PCR (7/8 were positive), and only 4 samples were simultaneously tested by both methods (1 positive by culture and 3 by PCR). In conclusion, although based on a restricted number of neonates and samples, our results suggest that the proposed nested-PCR might be used to diagnose GBS sepsis as it has successfully amplified the three types of biological samples analyzed (blood, urine and cerebrospinal fluid), and was more sensitive than culture methods as PCR in urine confirmed diagnosis...

O estreptococo do grupo B (GBS) constitui a causa mais freqüente de sepse neonatal precoce. O teste de referência continua sendo o isolamento em cultura, apesar de apresentar problemas de sensibilidade. O objetivo do presente estudo foi validar uma técnica de dupla amplificação e determinar a possibilidade do uso de amostras residuais de urina colhidas por método não invasivo, não estéril, para a confirmação da sepse por GBS em recém-nascidos. As amostras foram amplificadas com primers do principal gene de superfície do GBS. A insuficiência de volume de material biológico para a realização de exames para suporte de vida, além de outros necessários à identificação do agente etiológico de infecções é muito freqüente em recém-nascidos. Mesmo assim, decidimos definir critérios bastante rigorosos para a inclusão de pacientes na casuística: os recém-nascidos deveriam apresentar sinais e sintomas compatíveis com infecção pelo GBS; deveriam ter tido ao menos uma amostra enviada para cultura, podendo ser sangue, urina ou líquor; disponibilidade de volumes residuais dessas amostras, ou de outras colhidas no dia da hospitalização, antes da introdução da antibioticoterapia, de forma a possibilitar a análise por PCR, e evolução favorável com a antibioticoterapia empírica. Em apenas um dos quatro recém-nascidos a infecção foi confirmada por cultura, enquanto nos outros três casos a infecção foi considerada presuntiva (pacientes preencheram os critérios de inclusão, mas o GBS não foi isolado). De um total de 12 amostras dos quatro pacientes (5 de sangue, 3 de líquor e 4 de urina), 8 foram testadas por cultura (2 foram positivas), 8 foram testadas por PCR (7 foram positivas), e apenas 4 pelos dois métodos simultaneamente (1 positiva por cultura e 3 por PCR). Concluímos que apesar do número restrito de pacientes e de amostras testadas, os resultados apresentados sugerem que a amplificação proposta poderia ser usada para o diagnóstico...

Diagnosis of neonatal group B Streptococcus sepsis by nested-PCR of residual urine samples.

Group B streptococcus (GBS) remains the most common cause of early-onset sepsis in newborns. Laboratory gold-standard, broth culture methods are highly specific, but lack sensitivity. The aim of this study was to validate a nested-PCR and to determine whether residue volumes of urine samples obtained by non invasive, non sterile methods could be used to confirm neonatal GBS sepsis. The nested-PCR was performed with primers of the major GBS surface antigen. Unavailability of biological samples to perform life supporting exams, as well as others to elucidate the etiology of infections is a frequent problem concerning newborn patients. Nevertheless, we decided to include cases according to strict criteria: newborns had to present with signs and symptoms compatible with GBS infection; at least one of the following biological samples had to be sent for culture: blood, urine, or cerebrospinal fluid; availability of residue volumes of the samples sent for cultures, or of others collected on the day of hospitalization, prior to antibiotic therapy prescription, to be analyzed by PCR; favorable outcome after GBS empiric treatment. In only one newborn GBS infection was confirmed by cultures, while infection was only presumptive in the other three patients (they fulfilled inclusion criteria but were GBS-culture negative). From a total of 12 biological samples (5 blood, 3 CSF and 4 urine specimen), eight were tested by culture methods (2/8 were positive), and 8 were tested by PCR (7/8 were positive), and only 4 samples were simultaneously tested by both methods (1 positive by culture and 3 by PCR). In conclusion, although based on a restricted number of neonates and samples, our results suggest that the proposed nested-PCR might be used to diagnose GBS sepsis as it has successfully amplified the three types of biological samples analyzed (blood, urine and cerebrospinal fluid), and was more sensitive than culture methods as PCR in urine confirmed diagnosis in all four patients. Moreover, PCR has enabled us to use residue volumes of urine samples collected by non invasive, non sterile methods, what is technically adequate as GBS is not part of the normal urine flora, thus avoiding invasive procedures such as suprapubic bladder punction or transurethral catheterization. At the same time, the use of urine instead of blood samples could help preventing newborns blood spoliation.

Diagnosis of neonatal group B Streptococcus sepsis by nested-PCR of residual urine samples

Group B streptococcus (GBS) remains the most common cause of early-onset sepsis in newborns. Laboratory gold-standard, broth culture methods are highly specific, but lack sensitivity. The aim of this study was to validate a nested-PCR and to determine whether residue volumes of urine samples obtained by non invasive, non sterile methods could be used to confirm neonatal GBS sepsis. The nested-PCR was performed with primers of the major GBS surface antigen. Unavailability of biological samples to perform life supporting exams, as well as others to elucidate the etiology of infections is a frequent problem concerning newborn patients. Nevertheless, we decided to include cases according to strict criteria: newborns had to present with signs and symptoms compatible with GBS infection; at least one of the following biological samples had to be sent for culture: blood, urine, or cerebrospinal fluid; availability of residue volumes of the samples sent for cultures, or of others collected on the day of hospitalization, prior to antibiotic therapy prescription, to be analyzed by PCR; favorable outcome after GBS empiric treatment. In only one newborn GBS infection was confirmed by cultures, while infection was only presumptive in the other three patients (they fulfilled inclusion criteria but were GBS-culture negative). From a total of 12 biological samples (5 blood, 3 CSF and 4 urine specimen), eight were tested by culture methods (2/8 were positive), and 8 were tested by PCR (7/8 were positive), and only 4 samples were simultaneously tested by both methods (1 positive by culture and 3 by PCR). In conclusion, although based on a restricted number of neonates and samples, our results suggest that the proposed nested-PCR might be used to diagnose GBS sepsis as it has successfully amplified the three types of biological samples analyzed (blood, urine and cerebrospinal fluid), and was more sensitive than culture methods as PCR in urine confirmed diagnosis in all four patients. Moreover, PCR has enabled us to use residue volumes of urine samples collected by non invasive, non sterile methods, what is technically adequate as GBS is not part of the normal urine flora, thus avoiding invasive procedures such as suprapubic bladder punction or transurethral catheterization. At the same time, the use of urine instead of blood samples could help preventing newborns blood spoliation.

O estreptococo do grupo B (GBS) constitui a causa mais freqüente de sepse neonatal precoce. O teste de referência continua sendo o isolamento em cultura, apesar de apresentar problemas de sensibilidade. O objetivo do presente estudo foi validar uma técnica de dupla amplificação e determinar a possibilidade do uso de amostras residuais de urina colhidas por método não invasivo, não estéril, para a confirmação da sepse por GBS em recém-nascidos. As amostras foram amplificadas com primers do principal gene de superfície do GBS. A insuficiência de volume de material biológico para a realização de exames para suporte de vida, além de outros necessários à identificação do agente etiológico de infecções é muito freqüente em recém-nascidos. Mesmo assim, decidimos definir critérios bastante rigorosos para a inclusão de pacientes na casuística: os recém-nascidos deveriam apresentar sinais e sintomas compatíveis com infecção pelo GBS; deveriam ter tido ao menos uma amostra enviada para cultura, podendo ser sangue, urina ou líquor; disponibilidade de volumes residuais dessas amostras, ou de outras colhidas no dia da hospitalização, antes da introdução da antibioticoterapia, de forma a possibilitar a análise por PCR, e evolução favorável com a antibioticoterapia empírica. Em apenas um dos quatro recém-nascidos a infecção foi confirmada por cultura, enquanto nos outros três casos a infecção foi considerada presuntiva (pacientes preencheram os critérios de inclusão, mas o GBS não foi isolado). De um total de 12 amostras dos quatro pacientes (5 de sangue, 3 de líquor e 4 de urina), 8 foram testadas por cultura (2 foram positivas), 8 foram testadas por PCR (7 foram positivas), e apenas 4 pelos dois métodos simultaneamente (1 positiva por cultura e 3 por PCR). Concluímos que apesar do número restrito de pacientes e de amostras testadas, os resultados apresentados sugerem que a amplificação proposta poderia ser usada para o diagnóstico de sepse pelo GBS, uma vez que a amplificação foi possível nos três tipos de materiais biológicos testados (sangue, urina e líquor), e a PCR foi mais sensível que as culturas por ter conseguido confirmar a infecção na urina dos quatro pacientes, usando volumes residuais de amostras colhidas por método não invasivo, não estéril, o que é tecnicamente adequado uma vez que o GBS não faz parte da flora normal da urina, evitando procedimentos invasivos, tais como a punção supra-púbica da bexiga ou a cateterização transuretral. Ao mesmo tempo, o uso de urina em lugar de sangue ajuda a prevenir a espoliação sangüínea dos recém-nascidos.

Fatores de risco para o desenvolvimento de sepse neonatal precoce em hospital da rede pública do Brasil / Risk factors for early-onset neonatal sepsis in Brazilian public hospital short-title: early-onset neonatal sepsis

JUSTIFICATIVA E OBJETIVOS: O conhecimento dos fatores de risco associados à sepse neonatal precoce em unidade de neonatologia, inserida na realidade de nosso sistema de saúde, no sentido de se detectar, prevenir e adotar medidas específicas e reduzir as taxas de mortalidade nessa faixa etária. O objetivo deste estudo foi determinar os fatores de risco associados a sepse neonatal precoce em hospital de referência em neonatologia ligado à rede pública de saúde. MÉTODO: Foi realizado um estudo observacional, prospectivo, tipo caso-controle. Foram incluídos os recém-nascidos com diagnóstico de sepse precoce e como controle, recém-nascidos sem infecção neonatal nascido na mesma data do recém-nascido considerado como caso. Foram incluídos 50 casos e três controles para cada caso, resultando em amostra total de 200 pacientes. Foi considerada estatisticamente significativa a associação quando p < 0,05. RESULTADOS: A freqüência de sepse neonatal precoce no período foi de 50,3 casos para 1000 nascidos vivos. As associações estatisticamente significativas entre os fatores de risco e o desenvolvimento de sepse neonatal precoce foram prematuridade (OR 9,33; p < 0,001), baixo peso ao nascimento (OR 11,74; p < 0,001), presença de infecção materna (OR 2,28; p = 0,009), filho anterior com infecção neonatal (OR 6,43; p = 0,035) e ruptura de membranas mais de 18 horas antes do nascimento (OR 9,33; p = 0,001). CONCLUSÕES: A freqüência de sepse neonatal precoce foi elevada no período do estudo. A prematuridade, o baixo peso ao nascimento, a infecção materna e a ruptura prolongada de membranas são fatores de risco estatisticamente significativos para sepse neonatal precoce.

BACKGROUND AND OBJECTIVES: The determination of the risk factors to early-onset neonatal sepsis in our country is essential to prevent and reduce the mortality associated with this syndrome. Thus, the objective of this study was to determine the frequency and associated risk factors to early-onset neonatal sepsis in public hospital in Southern Brazil. METHODS: Observational, case-control study. Were included neonates with diagnostic of early-onset neonatal sepsis and as controls, neonates without neonatal infection. Were included 50 cases and 3 controls for each case resulting in a total sample of 200 patients. Associations were considered significant when p < 0.05. RESULTS: The sepsis frequency was 50.3 per 1000 born-alive. Risk factors associated to the development of neonatal sepsis were prematurity (OR 9.33; p < 0.001), low birth weight (OR 11.74; p < 0.001), maternal infection (OR 2.28; p = 0.009), mother with history of previous infant with neonatal sepsis (OR 6.43; p = 0.035) and rupture of the membranes more than 18 hours before delivery (OR 9.33; p = 0.001). CONCLUSIONS: Neonatal sepsis was very frequent in the study. Prematurity, low birth weight, maternal infection and motherÆs having had a previous infant with neonatal sepsis are risk factors for early-onset neonatal sepsis.