How can the microbiologist help in diagnosing neonatal sepsis?

Pediatric blood cultures-turning up the volume: a before and after intervention study

The major determinant of blood culture (BC) diagnostic performance is blood volume, and pediatric sample volumes are frequently low. We aimed to assess BC volumes in our institution, design an intervention to increase volumes, and assess its impact. All pediatric BCs submitted over a 7-month period to the microbiology laboratory in a university hospital (including emergency department, pediatric ward, and neonatal unit) were included. A pre-intervention period assessed current practice. A multi-faceted intervention (education, guideline introduction, active feedback strategies) was collaboratively designed by all stakeholders. Impact was assessed in a post-intervention period. The main outcome measures included the percentage of samples adequately filled using three measures of sample adequacy (1) manufacturer-recommended minimum validated volume-> 0.5 ml, (2) manufacturer-recommended optimal minimum volume-> 1.0 ml, (3) newly introduced age-specific recommendations. Three hundred ninety-eight pre-intervention and 388 post-intervention samples were included. Initial volumes were low but increased significantly post-intervention (median 0.77 ml vs. 1.52 ml), with multivariable regression analysis estimating volumes increased 89% post-intervention. There were significant increases in all measures of volume adequacy, including an increase in age-appropriate filling (20.4-53.1%), with less improvement in those aged > 3 years. Overall, 68.4% of pathogens were from adequately filled cultures, while 76% of contaminants were from inadequately filled cultures. A pathogen was detected in a higher proportion of adequately filled than inadequately filled cultures (9.4% vs. 2.2%, p < 0.001).  Conclusion: Blood volume impacts BC sensitivity, with lower volumes yielding fewer pathogens and more contaminants. Focused intervention can significantly improve volumes to improve diagnostic performance. What is Known: • Blood volume is the major determinant of blood culture positivity, and yet pediatric blood culture volumes are frequently low, resulting in missed pathogens and increased contamination. What is New: • Adequately filled (for age) blood cultures have a pathogen detection rate three times higher than inadequately filled blood cultures. • This interventional study shows that collaboratively designed multi-modal interventions including focus on accurate volume measurement can lead to significant increases in blood volumes and improve blood culture diagnostic performance.

Late onset neonatal sepsis: Can plasma gelsolin be a promising diagnostic marker?

Plasma gelsolin (pGSN) correlates with clinical improvement in septic patients. We aimed to investigate pGSN levels as a diagnostic and prognostic marker of neonatal late-onset-sepsis (LOS). A case-control study was done on 184 neonates (92 with LOS and 92 controls). All participants were subjected to detailed history taking, full clinical evaluation, sepsis workup, and pGSN enzyme-linked immunosorbent-assay measurement. We detected significantly lower pGSN level among cases compared to controls (90.63 ± 20.64 vs 451.83 ± 209.59). It was significantly related to the severity of sepsis and mortality, with significantly lower values among cases with septic shock and multiorgan failure and non-survivors. Follow-up pGSN significantly increased after sepsis improvement in survivors compared to admission values. pGSN might be a reliable diagnostic and prognostic marker for LOS.

Sepsis Risk Factors in Neonatal Intensive Care Units of Public Hospitals in Southeast Ethiopia, 2020: A Retrospective Unmatched Case-Control Study

Background

Neonatal sepsis is a significant contributor to neonatal morbidity and mortality worldwide. It is more prevalent in developing countries. Thus, understanding the risk factors for neonatal sepsis is critical to minimizing the incidence of infection, particularly in Ethiopia. The purpose of this study was to identify the risk factors for neonatal sepsis in neonates admitted to neonatal intensive care units of public hospitals in Southeast Ethiopia in 2020.

Method

An institution-based, retrospective unmatched case-control study was conducted on 97 cases and 194 controls in neonatal intensive care units of public hospitals in Southeast Ethiopia. A pretested, structured questionnaire was used to collect the data. Data was entered using EpiData 3.1 and analyzed using SPSS version 23. Bivariable and multivariable logistic regression analyses were performed to identify associated factors. An adjusted odds ratio with a 95% confidence interval was used to determine the degree of association, and statistical significance was declared at a p value of < 0.05.

Results

In this study, 97 cases and 194 controls were included. About two-thirds (63.9%) of cases were with early onset neonatal sepsis (<7 days). Mode of delivery with spontaneous vaginal delivery (AOR:5.032; 95% CI (1.887-13.418)), type of birth attendant (traditional birth attendant) (AOR: 4.407 95% CI (1.213,16.004)), history of STI/UTI (AOR:2.543; 95% CI (1.313,4.925)), intrapartum fever (AOR:4.379; 95% CI (2.170,8.835)), APGAR score at the 5thminute < 7 (AOR:4.832; 95% CI (1.862,12.537)), neonate received resuscitation (AOR:3.830; 95% CI (1.753,8.369)), low birth weight (AOR:6.101; 95% CI (2.124,17.525)) were the identified risk factors for neonatal sepsis.

Conclusion

Both maternal and neonatal factors contribute to the risk of neonatal sepsis. Spontaneous vaginal delivery, birth attended by the traditional birth attendant, history of STI/UTI, presence of intrapartum fever, low APGAR score at the 5th minute, neonate receiving resuscitation, and low birth weight were identified as independent risk factors for neonatal sepsis. Prompt identification of the aforementioned factors and management should be sought for all newborns.

Development and internal validation of a Neonatal Healthcare-associated infectiOn Prediction score (NeoHoP score) for very low birthweight infants in low-resource settings: a retrospective case-control study

BACKGROUND AND OBJECTIVES

Early diagnosis of neonatal infection is essential to prevent serious complications and to avoid unnecessary use of antibiotics. The prevalence of healthcare-associated infections (HAIs) among very low birthweight (VLBW; <1500 g) infants is 20%; and the mortality in low-resource settings can be as high as 70%. This study aimed to develop an Infection Prediction Score to diagnose bacterial HAIs.

METHODS

A retrospective cohort of VLBW infants investigated for HAI was randomised into two unmatched cohorts. The first cohort was used for development of the score, and the second cohort was used for the internal validation thereof. Potential predictors included risk factors, clinical features, interventions, and laboratory data. The model was developed based on logistic regression analysis.

RESULTS

The study population of 655 VLBW infants with 1116 episodes of clinically suspected HAIs was used to develop the model. The model had five significant variables: capillary refill time >3 s, lethargy, abdominal distention, presence of a central venous catheter in the previous 48 hours and a C reactive protein ≥10 mg/L. The area below the receiver operating characteristic curve was 0.868. A score of ≥2 had a sensitivity of 54.2% and a specificity of 96.4%.

CONCLUSION

A novel Infection Prediction Score for HAIs among VLBW infants may be an important tool for healthcare providers working in low-resource settings but external validation needs to be performed before widespread use can be recommended.

Coagulase-Negative Staphylococci in Neonatal Blood: How Concerning?

Objective Coagulase-negative staphylococci (CoNS) are being implicated as one of the leading causes of bloodstream infection (BSI). To study the spectrum, prevalence, and antimicrobial susceptibility of CoNS causing BSI in neonates.

Materials and Methods A cross-sectional study was done in level III neonatal intensive care unit (NICU). Blood samples in automated culture bottles were processed as per the standard technique. Previously validated methods were followed for the characterization of CoNS and for AST of standard antibiotics by Kirby Bauer disk diffusion and vancomycin by agar dilution. The prevalence of causative organisms and susceptibility of CoNS were statistically analyzed. Categorical variables were compared by chi-square or Fisher's exact probability tests.

Result In total, 1,365 blood samples (1,365 neonates) were studied, of which 383 (28.05%) were positive and 982 (71.94%) were negative. Gram-positive organisms (GPC) predominated (n = 238; 62.14%) (p < 0.001) with 41.77% (160/383) S. aureus and 13.83% (53/383) CoNS. CoNS included S. epidermidis (19, 38%), S. haemolyticus (7, 14%), S. hominis (6, 12%), S. simulans (6,12%), S. capitis (5,10%), S. cohnii (4, 8%), S. warneri (1, 2%), and S. xylosus (1, 2%). The susceptibility to netilmicin, linezolid, and vancomycin was 100% (p ≤ 0.001), and 54% (n = 27) had vancomycin MIC of 0.125 μg/mL but methicillin-resistant CoNS (MRCoNS) was 70%. Methicillin-susceptible (MS) CoNS had lower MIC of vancomycin (p < 0.05) than MRCoNS.

Conclusion The spectrum of pathogens causing BSI in neonates is changing with predominance of GPC and among CoNS, S. epidermidis. Considerable proportion of MRCoNS with the emergence of MIC creep for vancomycin requires immediate attention.

Double Blood Culture Policy Is More Effective Than Single In Neonatal Intensive Units

Aim: Blood culture (BC) sampling and antibiotic administration are common practices in Neonatal Intensive Care Units(NICUs). However, false positive BC results might affect clinician’s decision and lead to inappropriate antibiotic treatments. The aim of this study was to investigate the effect of double culture on clinical application. Material and Methods: The study was conducted retrospectively. The blood culture results of the patients admitted to the NICU between 2016-2019 were analyzed. Considering sepsis before 2017, we took only one sample from the patient. After this period, we started to take double blood cultures. Time frames of BCs were investigated to two groups as early and late onset sepsis fistly, and then subgroups as; a-) Group 1, BCs in the first 24 hours, b-)Group 2, between 24 to 72 hours, and c-)Group 3, after 72 hours. Results: Total of 1747 BC samples were taken in study. Majority of BCs were in Group 3(62%). Male/female ratio was 1.3:1. Staphylococcus Epidermidis(S. Epi) was major source for the contamination. But, by taking dBCs, we were able to eliminate most S.Epi contamination in Group 2 (11%vs.3%) and in Group 3(41%to14%). We were able to identify some resistant Gr(-) pathogens in one arm although the other arm was negative, by taking dBC. Conclusions: Our study indicates that dBC policy in NICUs could help to clinicians for judicious decision in antibiotic use and decrease unnecessary antibiotic exposure of infants. Also it could be enable to detect some highly pathogen microorganism easily. Key words: Newborn, Septicemia, Blood culture, Coagulase Negative Staphylococci, contamination

Healthcare-associated Infections in Very Low Birth-weight Infants in a South African Neonatal Unit: Disease Burden, Associated Factors and Short-term Outcomes

BACKGROUND

Infection is a leading cause of death among very low birth-weight (VLBW) infants in resource-limited settings.

METHODS

We performed a retrospective review of healthcare-associated infection (HAI) episodes among VLBW infants from January 1, 2016, to December 31, 2017. The epidemiology, causative organisms and short-term outcomes were analyzed. Logistic regression was used to investigate for factors associated with development of HAI.

RESULTS

During the study period, 715 VLBW infants with suspected HAI were investigated, including 162/715 (22.7%) proven and 158/715 (22.1%) presumed HAI. Of the proven infections, 99/162 (61.1%) contained at least one Gram-negative organism per blood culture; 84/162 (51.9%) single Gram-negative organisms and 15/162 (9.3%) polymicrobial growth. Independent factors associated with development of any HAI included low gestational age, small for gestational age, indwelling central venous catheter and invasive ventilation. Compared with infants in whom HAI had been excluded, infants with HAI were more likely to be diagnosed with necrotizing enterocolitis (5.6% vs. 23.1%; P &lt; 0.001) and bronchopulmonary dysplasia (1.0% vs. 4.4%; P = 0.007). Infants with any HAI also had a longer hospital stay [44 (25-65) vs. 38 (26-53) days; P &lt; 0.001] and increased mortality [90/320 (28.1%) vs. 21/395 (5.3%); P &lt; 0.001] compared with infants who did not develop HAI episodes.

CONCLUSIONS

Proven and presumed HAI are a major contributor to neonatal morbidity and mortality; further research is urgently needed to better understand potential targets for prevention and treatment of HAI in resource-limited neonatal units.

Bacteriological profile and antibiogram of blood culture isolates from bloodstream infections in a rural tertiary hospital in Nigeria

Background

Bloodstream infections (BSIs) are a cause of significant morbidity and mortality requiring urgent antibiotic treatment. However, there is widespread antibiotic-resistance from the bacterial causes, necessitating regular surveillance for drug-resistant bacteria and their antibiograms.

Objective

This study isolated and identified various bacterial causes of BSIs, determined their antibiotic susceptibility patterns, and determined the best empirical treatment for cases of BSI in the setting.

Methods

A cross-sectional study was carried out at the Federal Teaching Hospital, Ido-Ekiti, Nigeria between June 2020 and February 2021 on 177 blood culture samples from cases of BSI. Identification of isolated bacteria and antibiotic susceptibility testing of the isolates were carried out following the standard protocol.

Results

Culture positivity in this study was 19.2%. No significant difference was seen in culture positivity between male and female participants (p = 0.97). Gram-negative enteric bacteria were predominantly isolated (67.6%), including Escherichia coli (29.4%) and Klebsiella aerogenes (20.6%). Staphylococcus aureus was the most common Gram-positive bacterium isolated (23.5%). Three (37.5%) S. aureus isolates were methicillin-resistant. All isolates were sensitive to meropenem, and 97.1% were sensitive to imipenem; other sensitivity patterns were: ceftazidime (85.3%), ciprofloxacin (79.4%), ofloxacin (79.4%), and gentamicin (76.5%). There was low sensitivity to ampicillin (32.4%) and cotrimoxazole (38.2%). All Gram-positive isolates, including methicillin-resistant S. aureus, were sensitive to vancomycin.

Conclusion

Regular surveillance of isolate sensitivity patterns, formulation of hospital antibiotic policies based on existing data and compliance with treatment guidelines will promote rational antibiotic use and reduce resistance among bacteria.

Predictors of mortality among neonates hospitalized with neonatal sepsis: a case control study from southern Ethiopia

Background

Neonatal sepsis, which resulted from bacterial, viral, and fungal invasions of the bloodstream, is the major cause of neonatal mortality and neurodevelopmental impairment among neonates. It is responsible for more than one-third of neonatal deaths in Ethiopia. Frequently neonates referred to health facilities are at high risk of death. Hence, assessing and preventing the predictors of mortality in neonatal sepsis helps to reduce the burden of neonatal mortality.

Objectives

To determine predictors of mortality among neonates admitted with sepsis at Durame general hospital, southern Ethiopia, 2020.

Methods

Institution-based unmatched case-control study was carried out from March 8 to 30, 2020, among 219 neonates in Durame general hospital in southern Ethiopia. Neonates admitted with sepsis and died were considered as cases and neonates admitted with sepsis and survived (discharged alive) as controls. Cases were selected by taking the deaths of neonates consecutively among those neonates admitted with the diagnosis of neonatal sepsis. The next immediate three corresponding controls were selected by lottery method from the Neonatal Intensive Care Unit (NICU) case registration book. Data was collected by using structured pretested checklists from neonates’ records and then entered into Epi data version 3.1 and exported to SPSS version 20. Logistic regression was used to identify the predictors of mortality. Statistical significance was declared at P < 0.05.

Results

A total of 55 cases and 164 controls were included in this study. More than three quarters (81.8%) of cases had early onset sepsis. The multivariable logistic regression analysis showed that predictors of mortality in this study were; poor feeding [AOR = 4.15; 95% CI (1.64, 10.49)], respiratory distress [AOR = 2.72; 95% CI (1.31, 5.61)], estimated gestational age less than 37 weeks [AOR = 4.64; 95% CI (2.17, 9.91)], and convulsion [AOR = 3.13; 95% CI (1.12, 8.76)].

Conclusion

This study showed that prematurity, convulsion, poor feeding, and respiratory distress were the predictors of sepsis-related neonatal mortality. It is important to pay attention to septicemic babies with any of the identified predictors to reduce sepsis-related mortality.

Performance Comparison of Infection Prediction Scores in a South African Neonatal Unit: A Retrospective Case-Control Study

BACKGROUND AND OBJECTIVES

Infection prediction scores are useful ancillary tests in determining the likelihood of neonatal hospital-acquired infection (HAI), particularly in very low birth weight (VLBW; <1,500 g) infants who are most vulnerable to HAI and have high antibiotic utilization rates. None of the existing infection prediction scores were developed for or evaluated in South African VLBW neonates.

METHODS

We identified existing infection prediction scores through literature searches and assessed each score for suitability and feasibility of use in resource-limited settings. Performance of suitable scores were compared using a retrospective dataset of VLBW infants (2016-2017) from a tertiary hospital neonatal unit in Cape Town, South Africa. Sensitivity, specificity, predictive values, and likelihood ratios were calculated for each score.

RESULTS

Eleven infection prediction scores were identified, but only five were suitable for use in resource-limited settings (NOSEP1, Singh, Rosenberg, and Bekhof scores). The five selected scores were evaluated using data from 841 episodes of HAI in 659 VLBW infants. The sensitivity for the scores ranged between 3% (NOSEP1 ≥14; proven and presumed infection), to a maximum of 74% (Singh score ≥1; proven infection). The specificity of these scores ranged from 31% (Singh score ≥1; proven and presumed infection) to 100% (NOSEP1 ≥11 and ≥14, NOSEP-NEW-1 ≥11; proven and presumed infection).

CONCLUSION

Existing infection prediction scores did not achieve comparable predictive performance in South African VLBW infants and should therefore only be used as an adjunct to clinical judgment in antimicrobial decision making. Future studies should develop infection prediction scores that have high diagnostic accuracy and are feasible to implement in resource-limited neonatal units.

Clinical Profile of Neonates Admitted with Sepsis to Neonatal Intensive Care Unit of Jimma Medical Center, A Tertiary Hospital in Ethiopia

Background

Globally, over 3 million newborn die each year, one million of these attributed to infections. The objective of this study was to determine the etiologies and clinical characteristics of sepsis in neonates admitted to intensive care unit of a tertiary hospital in Ethiopia.

Methods

A longitudinal hospital based cohort study was conducted from April 1 to October 31, 2018 at the neonatal intensive care unit of Jimma Medical Center, southwest Ethiopia. Diagnosis of sepsis was established using the World Health Organization's case definition. Structured questionnaires and case specific recording formats were used to capture the relevant data. Venous blood and cerebrospinal fluid from neonates suspected to have sepsis were collected.

Results

Out of 304 neonates enrolled in the study, 195 (64.1%) had clinical evidence for sepsis, majority (84.1%; 164/195) of them having early onset neonatal sepsis. The three most frequent presenting signs and symptoms were fast breathing (64.6%; 122/195), fever (48.1%; 91/195) and altered feeding (39.0%; 76/195). Etiologic agents were detected from the blood culture of 61.2% (115/195) neonates. Bacterial pathogens contributed for 94.8% (109/115); the rest being fungal etiologies. Coagulase negative staphylococci (25.7%; 28/109), Staphylococcus aureus (22.1%; 24/109) and Klebsiella species (16.5%; 18/109) were the most commonly isolated bacteria.

Conclusion

Majority of the neonates had early onset neonatal sepsis. The major etiologies isolated in our study markedly deviate from the usual organisms causing neonatal sepsis. Multicentre study and continuous surveillance are essential to tackle the current challenge to reduce neonatal mortality due to sepsis in Ethiopia.

Bacterial Isolates and Resistance Patterns in Preterm Infants with Sepsis in Selected Hospitals in Ethiopia: A Longitudinal Observational Study

Background: Neonatal sepsis is the third leading cause of neonatal mortality, behind prematurity and intrapartum-related complications. The main objectives of this study are to assess the proportion of sepsis in preterm newborns and identify the etiologic agents and their antibiotic sensitivity patterns. Methods: A longitudinal observational study was done from July 2016 to May 2018. Whenever clinical diagnosis of sepsis was made, blood cultures and antibiotic susceptibility tests were done. Result: We did 690 blood cultures, 255 (36.9%) showing bacterial growth. The most commonly isolated bacteria were Klebsiella species 78 (36.6%), Coagulase negative Staphylococcus 42 (19.7%) and Staphylococcus aureus 39 (18.3%). Gram-positive bacteria showed high resistance to penicillin (98.9%) and ceftriaxone (91.3%) whereas Gram-negative bacteria were highly resistant to gentamicin (83.2%) and ceftriaxone (83.2%). Conclusion: Resistance to the more commonly used antibiotics such as ampicillin and gentamycin was very high, necessitating reconsideration of the empiric use of these antibiotics.

Valuable Role of Neutrophil CD64 and Highly Sensitive CRP Biomarkers for Diagnostic, Monitoring, and Prognostic Evaluations of Sepsis Patients in Neonatal ICUs

Background

Neonatal sepsis (NS) is a very critical medical situation associated with high morbidities and mortalities. There is an utmost need for a new tool helping in early diagnosis and proper management of sepsis neonates. Neutrophil CD64 (nCD64) shows a very promising value in this concerning issue.

Aim

Evaluate the diagnostic, monitoring, and prognostic performances of nCD64 and highly sensitive CRP (hs-CRP) in NS as well as the possible best panel of biomarkers that can achieve the most desirable results.

Methods

Patients were enrolled from three neonatal intensive care units (NICUs) (n = 121 patients) and classified according to their initial sepsis evaluation into three groups: disease control group (n = 30), proven sepsis group (n = 17), and clinical sepsis group (n = 74). Laboratory evaluation included hs-CRP, complete blood count (CBC), and blood culture in addition to nCD64 (done by flow cytometry technique). Besides the diagnostic evaluations, follow-up evaluations were done for 40 patients after five days from the first time; patients were reclassified according to their outcome into the improved sepsis neonates' group (n = 26) and sepsis neonates without improvement (n = 14).

Results

Significant increase in nCD64 and hs-CRP results were present in sepsis groups compared to the disease controls (P < 0.001); nCD64 at 43% cutoff value could detect the presence of sepsis with 85.6% sensitivity and 93% specificity. Additionally, delta change percentage (dC%) between improved sepsis neonates and sepsis neonates without improvement showed a significant difference in the levels of both nCD64 (P < 0.001) and hs-CRP (P = 0.001).

Conclusion

Besides the promising diagnostic performance documented by nCD64 which is higher than the other laboratory sepsis biomarkers used routinely in NICUs, nCD64 has a valuable role in sepsis patients' monitoring and prognostic evaluation. hs-CRP was moderate in its diagnostic and monitoring results being less than that achieved by nCD64. Combined measurement of nCD64% and hs-CRP gives better diagnostic and monitoring performance than that achieved by any of them alone.

Distribution of Pathogenic Yeasts in Different Clinical Samples: Their Identification, Antifungal Susceptibility Pattern, and Cell Invasion Assays

Introduction

Species of genus Candida are part of the common microbiota of humans; however, some of the Candida species are known opportunistic pathogens. Formation of biofilms, resistance to antifungal drugs, and increase in asymptomatic infections demands more studies on isolation, identification and characterization of Candida from clinical samples.

Methods

The present manuscript deals with assessment of authentic yeast identification by three methods viz., DNA sequencing of 28S rRNA gene, protein profiles using MALDI-TOF MS, and colony coloration on chromogenic media. Antifungal susceptibility and in vitro cell invasion assays were performed to further characterize these isolates.

Results

Comparison of three methods showed that DNA sequence analysis correctly identified more than 99.4% of the isolates up to species level as compared to 89% by MALDI-TOF MS. In this study, we isolated a total of 176 yeasts from clinical samples and preliminary morphological characters indicated that these yeast isolates belong to the genus Candida. The species distribution of isolates was as follows: 75 isolates of Candida albicans (42.61%), 50 of C. tropicalis (28.40%), 22 of C. glabrata (12.5%), 14 of C. parapsilosis (7.95%) and 4 of Clavispora lusitaniae (2.27%). Other species like Cyberlindnera fabianii, Issatchenkia orientalis, Kluyveromyces marxianus, Kodamaea ohmeri, Lodderomyces sp., and Trichosporon asahii were less than 2%. Antifungal susceptibility assay performed with 157 isolates showed that most of the isolates were resistant to the four azoles viz., clotrimazole, fluconazole, itraconazole, and ketoconazole, and the frequency of resistance was more in non-albicans Candida isolates. The susceptibility to azole drugs ranged from 7% to 48%, while 75% of the tested yeasts were susceptible to nystatin. Moreover, 88 isolates were also tested for their capacity to invade human cells using HeLa cells. In vitro invasion assay showed that most of the C. albicans isolates showed epithelial cell invasion as compared to isolates belonging to C. glabrata, C. parapsilosis and C. tropicalis.

Discussion

The identification of yeasts of clinical origin by sequencing of 28S rRNA gene performed better than MALDI-TOF MS. The present study reiterates the world scenario wherein there is a shift from Candida strains to emerging opportunistic pathogens which were earlier regarded as environmental strains. The present study enlightens the current understanding of identification methods for clinical yeast isolates, increased antifungal drug resistance, epithelial cell invasion as a virulence factor, and diversity of yeasts in Indian clinical samples.

Etiology, clinical findings and laboratory parameters in neonates with acute bacterial meningitis

BACKGROUND AND OBJECTIVES

Neonatal meningitis is one of the most important and serious neonatal infections with a high mortality and morbidity rate. The present study aimed to investigate the causes, clinical signs, laboratory parameters and mortality rates in newborns with bacterial meningitis.

MATERIALS AND METHODS

This cross-sectional study was performed on 468 neonates aged 2-28 days admitted to NICU in Ghaem Hospital Mashhad, Iran by available sampling method during 2009-2018. Meningitis was confirmed according to positive results of CSF culture and clinical feature. By using researcher-made questionnaire, neonate's individual data including cardiopulmonary resuscitation, the Apgar score of the first and fifth minutes, gestational age, birth weight, clinical symptoms and laboratory data such as ESR, WBC and positive culture of CSF were studied.

RESULTS

Among 468 newborn suspected to infection, lumbar Puncture (LP) was performed for 233 cases (50%). Of 233 neonates, 148 neonates (63.5%) had negative results for CSF culture and 85 cases (36.5%) had positive CSF culture. 94% of cases with meningitis were born premature. Blood culture had positive results in 80% of infants with late-onset meningitis and negative in 20%. The most common clinical findings were respiratory symptoms (94%). Klebsiella pneumoniae and Entrobacter aerugenes were the most common microorganisms of meningitis. Gestational disorders were observed in 55.3% of newborns with meningitis. C-Reactive Protein (CRP) of neonates with meningitis was twice higher than normal cases, and leukocytes and proteins in the CSF in neonates with meningitis were higher than healthy ones. Finally, 36% of neonates with meningitis died in our study. For analyzing the relationships between variables, independent t-test was used after controlling the normality, and Chi-square was used for analyzing the relationship of variables with nominal scale.

CONCLUSION

The most common pathogens of meningitis were Klebsiella pneumoniae and Enterobacter aerogenes. Respiratory symptoms were the most common clinical signs, and laboratory symptoms included increased CRP, increased leukocytes and proteins in CSF.

Predictive model for bacterial late-onset neonatal sepsis in a tertiary care hospital in Thailand

Background

Early diagnosis of neonatal sepsis is essential to prevent severe complications and avoid unnecessary use of antibiotics. The mortality of neonatal sepsis is over 18%in many countries. This study aimed to develop a predictive model for the diagnosis of bacterial late-onset neonatal sepsis.

Methods

A case-control study was conducted at Queen Sirikit National Institute of Child Health, Bangkok, Thailand. Data were derived from the medical records of 52 sepsis cases and 156 non-sepsis controls. Only proven bacterial neonatal sepsis cases were included in the sepsis group. The non-sepsis group consisted of neonates without any infection. Potential predictors consisted of risk factors, clinical conditions, laboratory data, and treatment modalities. The model was developed based on multiple logistic regression analysis.

Results

The incidence of late proven neonatal sepsis was 1.46%. The model had 6 significant variables: poor feeding, abnormal heart rate (outside the range 100–180 x/min), abnormal temperature (outside the range 36^o-37.9 °C), abnormal oxygen saturation, abnormal leucocytes (according to Manroe’s criteria by age), and abnormal pH (outside the range 7.27–7.45). The area below the Receiver Operating Characteristics (ROC) curve was 95.5%. The score had a sensitivity of 88.5% and specificity of 90.4%.

Conclusion

A predictive model and a scoring system were developed for proven bacterial late-onset neonatal sepsis. This simpler tool is expected to somewhat replace microbiological culture, especially in resource-limited settings.

Validity of biomarkers in screening for neonatal sepsis - A single center -hospital based study

BACKGROUND

The diagnosis of neonatal sepsis still considered to be a challenge for both clinicians and the laboratory due to the non-specific clinical presentations. The present study aimed to compare and assess the diagnostic & prognostic values of C-reactive protein (CRP), high sensitivity CRP (hsCRP), presepsin, interleukin-6 (IL-6) and procalcitonin (PCT) in neonatal sepsis separately and in combination.

METHODS

This hospital-based cross-sectional study has been conducted on 168 neonates recruited from the neonatal intensive care unit (NICU) of Qena University Hospitals, Upper Egypt. Measurements of CRP using latex agglutination test, hsCRP, presepsin, IL6 and PCT assays using commercially available ELISA assay kits were done to all included neonates.

RESULTS

There were significantly higher serum levels of CRP among late onset versus early onset sepsis group with significantly higher serum levels of hsCRP and presepsin among early onset compared with the late onset sepsis group (p < 0.05 for all). There were significantly higher hsCRP, presepsin and PCT serum levels in proven versus probable sepsis group (p < 0.05 for all). Significantly higher serum levels of presepsin and PCT were noted among survivors versus non survivors sepsis group (p < 0.05 for all). The cutoff value of the serum level of CRP >6 mg/dl showed lower sensitivity and specificity than that of hsCRP at cutoff >140 ng/ml in diagnosing neonatal sepsis. The cutoff value of presepsin >200 ng/ml showed equal sensitivity and specificity to IL-6 at cutoff >22 pg/ml. The cutoff value of PCT at > 389 pg/ml showed sensitivity and specificity approximate to that of hsCRP.

CONCLUSIONS

CRP could be a helpful prognostic marker in late onset neonatal sepsis. hsCRP and PCT have higher diagnostic accuracy in neonatal sepsis in comparison to other studied markers. Both IL-6 and presepsin have equal diagnostic utility in neonatal sepsis, but presepsin could be helpful diagnostic marker in early onset neonatal sepsis.

Clinical Characteristic and Pathogen Spectrum of Neonatal Sepsis in Guangzhou City from June 2011 to June 2017

Background

Preterm and low birth weight (birth weight <2500 g) neonates are vulnerable to sepsis, and the causative pathogens vary in different regions and times. The objective of this study was to identify common organisms leading to neonatal sepsis and identify the characteristic of patients infected with different bacteria, which may help in the selection of antibiotics for empirical treatment.

Material/Methods

We retrospectively collected the clinical and microbiological data of neonates with culture-proven sepsis in our clinical setting from June 2011 to June 2017. The demography, composition, and distribution of the pathogens and the clinical characteristic of the cases infected with different bacteria were analyzed.

Results

Of a total of 1048 bacteria that were isolated from patient samples, detailed clinical and microbiological data of 297 cases were available. Escherichia coli, Klebsiella pneumoniae, and coagulase-negative Staphylococcus (co-NS) were the top 3 isolated pathogens. Streptococcus agalactiae predominantly led to early-onset sepsis, while K. pneumoniae and Staphylococcus aureus mainly led to late-onset sepsis. K. pneumoniae was mainly acquired in the hospital. Leukopenia was more commonly seen than leukocytosis in our study, and patients infected with K. pneumoniae and Candida spp encountered more thrombocytopenia.

Conclusions

The results of our study revealed the composition of the pathogens of neonatal sepsis in our region and the clinical characteristic of sepsis caused by different bacteria; these data may help in the selection of antibiotics for empirical treatment of neonates with high risk of sepsis.

Blood culture indications in critically ill neonates: a multicenter prospective cohort study

Due to potential lethality of healthcare-associated sepsis (HAS), a low threshold for blood culturing and antimicrobial therapy (ABT) initiation is accepted. We assessed variability in the trigger for blood culturing between three neonatal intensive care units. A multicenter prospective cohort study was conducted. In newborns with suspicion of HAS, 10 predefined clinical signs, nosocomial sepsis (NOSEP) score, C-reactive protein, ABT initiation, and risk factors were registered at time of culturing. Outcome was lab-confirmed HAS, defined according to the NeoKISS-criteria. Two hundred ninety-nine suspected HAS episodes were considered in 212 infants, of which 118 had birth-weight ≤ 1500 g; proportion of lab-confirmed HAS per suspected episode was 30/192 (center 1), 28/60 (center 2), and 8/47 (center 3) (p < 0.001). Median C-reactive protein and number of clinical signs at time of culturing differed between centers 1, 2, and 3 (respectively 11 vs. 5 vs. 3 mg/L, p = 0.001; 1 sign [IQR 0-2, center 1] vs. 3 signs [IQR 2-4, centers 2 and 3], p < 0.001). Median NOSEP score at time of culturing was 5 (IQR 3-8, center 1), 5 (IQR 3-9, center 2), and 8 (IQR 5-11, center 3) (p = 0.016). Difference in ABT initiation was noticed (82 vs. 93 vs. 74%, p = 0.05).

CONCLUSION

Center heterogeneity in sampling practice is substantial. Optimizing sampling practice can be recommended. What is Known: • Blood culture test is a common diagnostic procedure in critically-ill newborns. • A low threshold for sampling and antimicrobial therapy initiation is accepted. What is New: • Variability in blood culture practice was assessed between 3 neonatal intensive care units by the registration of sampling frequencies, clinical indications, and antimicrobial therapy initiation.

SslE (YghJ), a Cell-Associated and Secreted Lipoprotein of Neonatal Septicemic Escherichia coli, Induces Toll-Like Receptor 2-Dependent Macrophage Activation and Proinflammation through NF-κB and MAP Kinase Signaling

SslE (YghJ), a cell surface-associated and secreted lipoprotein, was identified as a potential vaccine candidate for extraintestinal pathogenic Escherichia coli, providing nearly complete protection from sepsis in a mouse model. We earlier found that SslE from neonatal septicemic E. coli could trigger the secretion of various proinflammatory cytokines in murine macrophages, the signaling pathway of which is still obscure. In this study, we showed that SslE specifically binds to Toll-like receptor 2 (TLR2)/TLR1 heterodimers and recruits downstream adaptors MyD88, TIRAP, and TRAF6. In addition, SslE stimulates nuclear translocation of NF-κB and activates different mitogen-activated protein (MAP) kinase signaling cascades specific to the secretion of each cytokine in murine macrophages, which becomes impaired in TLR2 small interfering RNA (siRNA)-transfected cells and in cells blocked with a monoclonal antibody (MAb) against TLR2, suggesting the involvement of TLR2 in NF-κB and MAP kinase activation and subsequent cytokine secretion. Furthermore, our study is the first to show that SslE can stimulate TLR2-dependent production of other proinflammatory hallmarks, such as reactive nitrogen and oxygen species as well as type 1 chemokines, which contribute to the anti-infection immune response of the host. Also, the overexpression of major histocompatibility complex class II (MHC II) and other costimulatory molecules (CD80 and CD86) in macrophages essentially indicates that SslE promotes macrophage activation and M1 polarization, which are crucial in framing the host's innate immune response to this protein, and hence, SslE could be a potent immunotherapeutic target against E. coli sepsis.

Examining the utility of the CD64 index compared with other conventional indices for early diagnosis of neonatal infection

As specific clinical manifestations and detection tools for early neonatal infections are lacking, early detection and treatment are ongoing challenges. The present study aimed to investigate the role and clinical significance of the CD64 index in comparison with conventional examination indices (WBC, PCT and CRP) for the early diagnosis of neonatal infection. Of 74 in-patient newborns, non-sepsis (non-specific infection but free of sepsis), sepsis and control [newborns with ABO hemolytic disease of the newborn (ABOHDN) but without infection] groups involved 32, 16 and 26 cases, respectively. Peripheral blood WBC, PCT, CRP and CD64 indices were acquired for all groups. The sepsis group showed significantly higher WBC, PCT and CRP levels than the control group. Compared with the non-sepsis group, the sepsis group demonstrated significant increases in PCT but not in WBC or CRP. Compared with the control group, the non-sepsis and sepsis groups had higher CD64 indices. Combined, compared with the WBC, PCT and CRP indices, the CD64 index is unique in its capacity to diagnose neonatal infections early. The CD64 index combined with other conventional indices may lay a basis for the future early diagnosis and effective treatment of neonatal infections.

Rapid diagnosis of bloodstream infections in the critically ill: Evaluation of the broad-range PCR/ESI-MS technology

Bloodstream infection (BSI) and associated sepsis represent a major source of mortality in industrialized countries. Prompt treatment with targeted antibiotics affects both the financial impact and the clinical outcome of BSI: every hour gained in initiating the correct antimicrobial therapy significantly increases the probability of patient survival. However, the current standard-of-care, which depends on blood culture-based diagnosis, are often unable to provide such a fast response. Fast and sensitive molecular techniques for the detection of sepsis-related pathogens from primary blood samples are strongly needed. The aim of this study was to assess the usefulness of the IRIDICA BAC BSI Assay, a PCR/ESI-MS-based technology for the early diagnosis of bloodstream infections from primary blood samples in critical patients. This evaluation has been performed by comparison with the traditional culture-based methods. The study was performed on a total of 300 prospective whole blood specimens obtained from patients suspected of sepsis, admitted to enrolling ER units from The Greater Romagna Area. The overall concordance between the two techniques was of 86%, with a calculated sensitivity of 76% and an assay specificity of 90%. The clinical significance of discrepant results was evaluated reviewing the patients’ clinical records and the results of additional relevant microbiological tests. The data here obtained support the ability of the IRIDICA BAC BSI Assay to identify a broad range of bacteria directly from primary whole blood samples, within eight hours. This might allow a timely administration of a suitable treatment.

Diagnostic value of urine soluble triggering receptor expressed on myeloid cells (sTREM-1) for late-onset neonatal sepsis in infected preterm neonates

Objective

Sepsis is a complex clinical condition caused by a dysregulated immune response to an infection resulting in a fatal outcome. This study aimed to investigate the value of urine soluble triggering receptor expressed on myeloid cells (sTREM-1) for diagnosing culture-proven sepsis in preterm infants.

Methods

Preterm neonates were evaluated for late-onset sepsis (LOS). Laboratory investigations were performed. Urine sTREM-1 samples and blood cultures were synchronously collected. Using blood culture results, preterm neonates were divided into the culture-proven group and suspected sepsis group.

Results

A total of preterm 62 infants were included in the study; 31 had culture-proven sepsis and 31 were suspected as having sepsis. There were no significant differences in gestational age, sex, birth weight, and delivery mode between the groups. Neonates in the culture-proven group had significantly higher urine sTREM-1 levels than did those in the suspected sepsis group. Using a cut-off point for a urine sTREM-1 level of 78.5 pg/mL, the sensitivity was 0.90, specificity was 0.78, positive predictive value was 0.68, and negative predictive value was 0.94.

Conclusions

The present study highlights the role of urine sTREM-1 levels in LOS. Urine sTREM-1 may be a reliable and sensitive marker in detecting sepsis in preterm infants.

Can neutrophil to lymphocyte ratio predict late-onset sepsis in preterm infants?

BACKGROUND

The neutrophil to lymphocyte ratio (NLR) is an easily accessible biomarker that has been reported to represent disease severity in adult trials. The aim of this study was to evaluate the relationship between culture positiveness and NLR in cases where the reason of sepsis was considered, and to foresight an idea about the active agents.

METHODS

Preterm infants with birth weights ≤1500 g and/or ≤32 gestational weeks were eligible for this study. The postnatal age of all included infants was more than 3 days with clinical and laboratory signs of sepsis. According to the results of blood cultures, all enrolled infants were classified into 2 groups: the culture-proven septic infants and suspected septic infants. The NLR was calculated as the ratio of neutrophil count to lymphocyte count. Initial laboratory investigations included WBC count, platelet count (PLT), C-reactive protein (CRP), and blood cultures.

RESULTS

A total of 127 infants were involved: 57 culture-proven sepsis and 75 suspected sepsis. There were no significant differences between groups regarding gestational age, gender, birth weight, delivery mode, and postnatal age. Receiver operating curve analysis for NLR and CRP was calculated. The area under the curve corresponded to 0.78 ± 0.04 (NLR) vs 0.55 ± 0.05 (CRP). Using a cutoff point of 1.77 for NLR, the sensitivity was 0.73, the specificity was 0.78, and accuracy rate was 0.76.

DISCUSSION

The prediction of NLR, an easy, inexpensive, and rapid method, along with CRP in the neonatal period for diagnosis of sepsis, will be more effective in detecting culture-proven sepsis and in decreasing unnecessary antibiotherapy.

Bacterial etiologic agents causing neonatal sepsis and associated risk factors in Gondar, Northwest Ethiopia

Background

Neonatal sepsis is a blood stream infection which is seen in the first month of life of the neonate. Bacterial profile of neonatal septicemia is constantly changing thus, current knowledge on the patterns of bacterial isolates, its antibiotic resistance profile, and associated factors, are essential to design and implement appropriate interventions. Therefore, the aim of this study was to identify bacterial etiologic agents, their antimicrobial susceptibility pattern and associated risk factors of neonatal sepsis among neonates.

Methods

A cross- sectional study was conducted among neonates suspected to sepsis attending University of Gondar Hospital from September/2015 to May/2016. A total of 251 consecutive neonates with clinical sign and symptoms of sepsis were included in the study. Blood sample was collected and directly inoculated into Trypton soya broth bottle and incubated at 37 °C. After 24 h of incubation it was sub- cultured in to blood agar plate, chocolate agar plate, manitol salt agar and Macconkey. The bacterial pathogens and antimicrobial susceptibility tests were identified using standard microbiological methods. Bivariate and multivariate logistic regressions were used to identify possible associated risk factors. Prior to the study ethical clearance was obtained from the School of Biomedical and Laboratory Sciences, University of Gondar.

Results

Of the 251 study participants suspected of neonatal sepsis, 117 (46.6%) showed bacterial growths, of them 120 bacteria were isolated. Gram positive bacteria were commonly isolated 81 (67.5%).The commonly isolated bacterial species were S. aureus 49 (40.8%) followed by coagulase negative Staphylococci 26 (21.6%) and K. pneumoniae19 (15.8%). The overall rate of multidrug resistance isolates was 78 (65%: CI 95%: 56.7–72.5%). Multidrug resistant (MDR) among Gram positive and negative bacteria were 56 (69.1%) and 22 (56.4%), respectively. Independent risk factors for the occurrence of neonatal sepsis were; Apgar score < 7/5 min (Adjusted odds ratio [AOR] =0.5), birth weight < 1.5 kg (AOR = 12.37), birth weight, 1.5–2.5 kg (AOR = 2.6), gestational week <37 weeks (AOR = 9) and caesarian section delivery (AOR = 5.2).

Conclusion

The isolation rate of bacterial pathogens in neonatal sepsis was considerably high. In addition, nearly 70% of isolates were MDR strains. Low birth weight, low Apgar score, preterm delivery and caesarian section modes of delivery were associated risk factors. Therefore, appropriate antenatal care follow up, and health education should be encouraged, especially on the importance of natural way of delivery.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0892-y) contains supplementary material, which is available to authorized users.

Rapid detection and ruling out of neonatal sepsis by PCR coupled with Electrospray Ionization Mass Spectrometry (PCR/ESI-MS)

BACKGROUND

Sepsis is an important cause of morbidity and mortality in neonates and clinicians are typically required to administer empiric antibiotics while waiting for blood culture results. However, prolonged and inappropriate use of antibiotics is associated with various complications and adverse events. Better tools to rapidly rule out bacterial infections are therefore needed.

AIMS

We aimed to assess the negative predictive value of PCR coupled with Electrospray Ionization Mass Spectrometry (PCR/ESI-MS) compared to conventional blood cultures in neonatal sepsis.

STUDY DESIGN

Prospective observational study.

SUBJECTS

All consecutive neonates (<28days old) with clinical suspicion of sepsis. Samples for PCR/ESI-MS analysis were collected at the same time as samples for the blood culture, before the initiation of antibiotics.

OUTCOME MEASURES

Our primary objective was to evaluate the negative predictive value of PCR/ESI-MS for the detection of bacteria in the bloodstream of newborns with suspected sepsis. Our secondary objective was the evaluation of the sensitivity, specificity and positive predictive value of the PCR/ESI-MS in such a neonatal population.

RESULTS

We analysed 114 samples over 14months. The median age and weight were 32weeks+3days and 1840g, respectively. Two patients had negative PCR/ESI-MS results, but positive blood cultures. Overall, the negative predictive value was 98% (95%CI: 92% to 100%).

CONCLUSIONS

Based on these results, PCR/ESI-MS analysis of blood samples of neonates with suspected sepsis appears to have a very good negative predictive value when compared to blood cultures as gold standard. This novel test might allow for early reassessment of the need for antibiotics.

Cerebral ultrasound abnormalities in preterm infants caused by late-onset sepsis

INTRODUCTION

This study describes cerebral ultrasound abnormalities caused by late-onset sepsis (LOS) in very preterm infants with a gestational age of < 32 weeks and/or birthweight < 1500 grams.

METHODS

The prospective study ("INFANT study") included 117 preterm infants with suspected LOS. Proven LOS was defined as a positive blood culture after 72 hours of life. In case of coagulase-negative staphylococci an elevated C-reactive protein was additionally required to establish proven LOS. Patients were identified as proven LOS and patients with only clinical symptoms of LOS. Cerebral ultrasound images were obtained in the first week after birth, during/after LOS and before discharge. Cerebral findings were divided in no/minor and major abnormalities.

RESULTS

Eighty-six preterm infants had proven LOS and 31 preterm infants had only clinical signs of LOS. Four infants were excluded because pre-existing major brain abnormalities. No significant differences (p = 0.624) for incidence of major brain abnormalities on cerebral ultrasound were found.

CONCLUSION

No differences were revealed in prevalence of major brain abnormalities between the groups with proven LOS and with clinical signs of LOS. Both infants with a gram negative sepsis developed major brain abnormalities, whereas only two of 66 preterm infants coagulase-negative staphylococci sepsis developed major brain abnormalities.

Simultaneous Two-site Blood Culture for Diagnosis of Neonatal Sepsis

OBJECTIVE

To evaluate efficacy of two blood cultures taken simultaneously from two different sites as compared to standard practice of single blood culture in diagnosis of neonatal sepsis.

STUDY DESIGN

Prospective cohort study.

Setting

A tertiary-care center at a public hospital.

PARTICIPANTS

475 neonates admitted to intensive care unit with suspected sepsis, from August 2014-July 2015.

INTERVENTION

Two blood cultures drawn from two different peripheral veins in patients with suspected neonatal sepsis.

MAIN OUTCOME MEASURES

Increase in culture-positivity rate with use of two blood cultures.

RESULTS

475 babies with suspected sepsis were enrolled. 185 patients had only first culture positive (38.9%). When we added second culture positivity, yield increased to 221 (46.5%). Adding on second culture increased the culture yield by 36 (7.6%; 95% CI 2.41 to 12.79; P=0.018). The most common organisms isolated were E. coli, S. aureus and Candida spp. Major morbidities and mortality were more common in blood culture positive patients Contamination was ruled out in 25 babies who grew Coagulase negative Staphylococcus (CONS) (n=10) and Candida spp. (n=15) in either of the two cultures.

CONCLUSION

Two blood cultures taken simultaneously from two different sites improve rate of pathogen detection as compared to routine practice of single blood culture.

Time to Positivity and Antibiotic Sensitivity of Neonatal Blood Cultures

Background:

Sepsis is a commonly encountered and potentially life-threatening problem in neonatal intensive care units, blood culture of neonatal sepsis helps in either optimizing treatment or terminating antibiotics.

Materials and Methods:

We determined the causative agent, time to positivity (TTP), and antibiogram of neonatal blood cultures collected in a tertiary care center, to investigate difference between early- and late-onset neonatal sepsis and to establish the time at which a blood culture could safely be considered negative, using the BacT/ALERT^® 3D 60. A total of 826 clinically suspected neonates suffering from sepsis and admitted to a neonatal intensive care unit of a tertiary care hospital, Alexandria, Egypt were included in this study.

Results:

Eighty-five (10.29%) showed positive results. The overall TTP median was 21.1 h. Out of the 85 positive cultures, 57 (67.06%) were Gram-positive, 15 (17.65%) were Gram-negative, and 13 (15.29%) were fungi (all Candida). Coagulase-negative staphylococci were the predominant organism (41.18%). All the Gram-positive pathogenic isolates were sensitive to vancomycin and tigecycline. Among the Gram-negative isolates, maximum antibiotic sensitivity was observed for levofloxacin.

Conclusion:

We conclude that more than 3 days of incubation may not be required when using the BacT/ALERT^® 3D 60 system.

Clinical and microbiological profile of babies born with risk of neonatal sepsis

The aim of the present study was to evaluate the effects of antibiotics on the condition of babies born with risk of neonatal sepsis. From March, 2014 to February, 2015, 200 neonates born with risk factors of septicemia in the Neonatal Intensive Care Unit at Xuzhou Central Hospital, were enrolled in the present study. Venous blood samples were collected within 6 h of birth using aseptic technique. Part of the blood specimens were cultured using BACTEC PEDS PLUS/F Culture Vials. Subsequently, the subcultures were prepared from each presumptive positive vial and bacterial isolates were identified. The remaining portion was used to measure the level of C-reactive protein (CRP) and total leukocyte count (TLC). The result showed that 32% of neonates were infected, of whom, 21.9% had Staphylococcus aureus, 21.9% had Acinetobacter Baumanni, and 12.5% had Klebsiella pneumoniae. Additionally, Staphylococcus epidermis, Enteroccus spp., Pseudomonas aeruginosa and E. coli was isolated from 9.4, 7.8, 6.3 and 4.7% of neonates, respectively. The neonates enrolled in the present study had ≥1 risk factor for neonatal sepsis, and the average number of risk factors was 1.95 per neonate. Neonates (39.1%) with positive blood culture results, had a CRP level >0.8 mg/dl, and 12.5% was shown to have an abnormal increase in their leukocyte counts. The association between leukocyte counts and blood culture results was not statistically significant. Of the neonates with positive blood cultures 45.3% died within 7 days after birth, while there was no mortality among those with negative culture results. The results indicate that in the presence of risk factors for sepsis, irrespective of clinical features of septicemia, neonatal sepsis screening should be performed. Rational and appropriate use of antibiotics may minimize the emergence of multidrug resistant bacteria in neonatal units.

Role in proinflammatory response of YghJ, a secreted metalloprotease from neonatal septicemic Escherichia coli

Neonatal sepsis is the invasion of microbial pathogens into blood stream and is associated with a systemic inflammatory response with production and release of a wide range of inflammatory mediators. The increased serum levels of cytokines were found to correlate with the severity and mortality in course of sepsis. There have been no reports on the role of microbial proteases in stimulation of proinflammatory response in neonatal sepsis. We have identified YghJ, a secreted metalloprotease from a neonatal septicemic Escherichia coli (NSEC) isolate. The protease was partially purified from culture supernatant by successive anion and gel filtration chromatography. MS/MS peptide sequencing of the protease showed homology with YghJ. YghJ was cloned, expressed and purified in pBAD TOPO expression vector. YghJ was found to be proteolytically active against Methoxysuccinyl Ala-Ala-Pro-Met-p-nitroanilide oligopeptide substrate, but not against casein and gelatin. YghJ showed optimal activity at pH 7-8 and at temperatures 37-40°C. YghJ showed clear changes in cellular morphologies of Int407, HT-29 and HEK293 cells. YghJ stimulated the secretion of cytokines IL-1α, IL-1β and TNF-α in murine macrophages (RAW 264.7) and IL-8 from human intestinal epithelial cells (HT-29). YghJ also down-regulated the production of anti-inflammatory cytokines such as IL-10. YghJ is present in both septicemic (78%) and fecal E. coli isolates (54%). However, expression and secretion of YghJ is significantly higher among the septicemic (89%) than the fecal isolates (33%). This is the first study to show the role of a microbial protease, YghJ in triggering proinflammatory response in NSEC.

Neonatal resuscitation equipment: A hidden risk for our babies?

AIM

Neonatal infections carry a heavy burden of morbidity and mortality. Poor practice can result in unintentional colonisation of medical equipment with potentially pathogenic organisms. This study will determine the prevalence and type of bacterial contamination on exposed neonatal resuscitation equipment in different clinical settings and explore simple measures to reduce contamination risk.

METHODS

A survey determined the rates of resuscitation equipment usage. All environmentally exposed items were identified on resuscitaires hospital-wide and swabbed for bacterial contamination. A new cleaning and storage policy was implemented and the prevalence of environmentally exposed equipment re-measured post-intervention.

RESULTS

Resuscitation equipment was used in 28% of neonatal deliveries. Bacterial colony forming units were present on 44% of the 236 exposed equipment pieces swabbed. There was no significant difference in contamination rates between equipment types. Coagulase negative staphylococcus was the most prevalent species (59 pieces, 25%) followed by Escherichia coli and Enterobacter cloacae (20 pieces, 9% each). Opened items stored inside plastic remained sterile, whilst those in low-use areas had significantly less contamination than those in high-use areas (22% vs. 51%, P < 0.05). Implementing a simple educational programme led to a significant reduction in environmentally exposed equipment (79% reduction, P < 0.01).

CONCLUSIONS

Pathogenic bacteria can colonise commonly used pieces of neonatal resuscitation equipment. Whilst the clinical significance remains uncertain, equipment should be kept packaged until required and discarded once open, even if unused. Standardising cleaning policies results in rapid and significant improvements in equipment storage conditions, reducing microbial colonisation opportunities.

The effect of Indomethacin and Betamethasone on the cytokine response of human neonatal mononuclear cells to gram-positive bacteria

Intrauterine infections with gram-positive bacteria pose a serious threat to neonates since they can result in neonatal sepsis, induce a fetal inflammatory response and also cause preterm birth. Despite intensive care, prematurity remains a leading cause of neonatal death, and is often accompanied by a number of morbidities. In order to prevent premature birth, tocolytic agents like Indomethacin are administered. Betamethasone is used to promote lung maturation and prevent respiratory distress syndrome. A combination of both drugs is assumed to prevent premature delivery while simultaneously facilitating lung maturation. This study investigates the effect of Betamethasone, Indomethacin and a combination of both on the cytokine production of neonatal cord blood mononuclear cells (CBMC) after stimulation with lysates of the gram-positive pathogens Streptococcus agalactiae and Enterococcus faecalis. The aim of the study is to determine the impact of these drugs on the function of the neonatal immune system which should aid clinicians in choosing the optimal therapy in case of preterm birth associated with intrauterine infection. Betamethasone reduced the production of the pro-inflammatory cytokines IL-6, IL-12p40, MIP-1α and TNF and increased the expression of the anti-inflammatory cytokine IL-10, depending on the pathogen used for stimulation. In contrast to Betamethasone, Indomethacin almost exclusively increased IL-10 production. The combination of both drugs decreased the expression of IL-6, IL-12p40, MIP-1α and TNF while increasing IL-10 production, depending on the concentration of Indomethacin and the pathogen used for stimulation. Based on our results, the combination therapy with Indomethacin and Betamethasone has a similar effect on cytokine production as Betamethasone alone, which is generally administered in case of impending preterm birth. However, the combination therapy has the advantage of promoting lung maturation while simultaneously blocking preterm labor effectively.

Epidemiological Evaluation of Blood Culture Patterns among Neonates Receiving Vancomycin

The objective of this study was to assess the frequency of blood culture (BC) collection among neonates who received vancomycin. Demographic, clinical, microbiologic, and pharmacy data were collected for 1275 neonates (postnatal age 0-27 days) who received vancomycin at an Intermountain Healthcare facility between 1/2006 and 9/2011. Neonates treated with vancomycin had a BC collected 94 % (n = 1198) of the time, of which 37 % (n = 448) grew one or more bacterial organisms (BC positive). Of these, 1 % (n = 5) grew methicillin-resistant Staphylococcus aureus (MRSA), 71 % (n = 320) grew coagulase-negative Staphylococci (CoNS), 9 % (n = 40) grew methicillin-sensitive Staphylococcus aureus (MSSA), and 22 % (n = 97) grew other bacterial species (total exceeds 100 % due to co-detection). In patients with negative BC or no BC, vancomycin therapy was extended beyond 72 h 52 % of the time. The median duration of vancomycin therapy for patients with a negative BC was 4 (IQR: 2-10) days. BCs were frequently obtained among neonates who received vancomycin. Vancomycin therapy beyond the conventional 'empiric' treatment window of 48-72 h was common without isolation of resistant gram-positive bacteria.

Neonatal bloodstream infections in a pediatric hospital in Vietnam: a cohort study

Septicemia and bloodstream infections (BSIs) are major causes of neonatal morbidity and mortality in developing countries. We prospectively recorded all positive blood cultures (BSI) among neonates admitted consecutively to a tertiary pediatric hospital in Vietnam during a 12-month period. Among 5763 neonates, 2202 blood cultures were performed, of which 399 were positive in 385 neonates. Among these, 64 died, 62 in relation to septicemia. Of the BSI isolates, 56% was known pathogenic and 48% was gram-negative bacteria, most frequently Klebsiella spp. (n = 78), Acinetobacter spp. (n = 58) and Escherichia coli (n = 21). Only three Streptococcus spp. were identified, none group B. Resistance against antibiotics applied was common. The mortality was highest in neonates with gram-negative BSI compared with no confirmed BSI and gram-positive BSI (P < 0.01). In this setting, the majority of BSI were likely to have been transmitted from the environment. Improvement of hygienic precautions and systematic BSI surveillance are recommended.

116 cases of neonatal early-onset or late-onset sepsis: A single center retrospective analysis on pathogenic bacteria species distribution and antimicrobial susceptibility

PURPOSE

The aim of this study was to explore the risk factors, clinical symptoms, hematological parameters, causative pathogen and antibiotic susceptibility of neonatal sepsis in a Chinese NICU.

METHODS

A retrospective survey was conducted on 116 cases of neonatal sepsis in NICU at the Maternal and Child Care Hospital in Shenzhen, China from January 2009 to December 2012. Patients were divided into early-onset sepsis (EOS) and late-onset sepsis groups according to their positive blood culture occurrence time (in the first 7 days of life or later).

RESULTS

116 cases of neonatal sepsis were divided into early-onset sepsis (EOS) group and late-onset sepsis (LOS) group. There was significant difference for risk factors like peripherally insertion central catheter (PICC) between two groups. The clinical symptoms or laboratory results such as chilly periphery, fever, jaundice, platelet and hemoglobin also had between-group differences. The most common responsible pathogenic bacteria species present in EOS group was Coagulase-negative Staphylococcus (CoNS). Among those CoNS Staphylococcus epidermidis provided 24.24%, and Staphylococcus haemolyticus contributed 13.63%. Both were sensitive to vancomycin, teicoplanin and linezolid. The most common responsible pathogenic bacteria species in LOS group was Staphylococcus epidermidis (16%). Antimicrobial susceptibility in EOS group is higher than in LOS group.

CONCLUSION

PICC is a bigger risk factor for neonatal late-onset sepsis. Staphylococcus epidermidis was the leading pathogen present in neonatal sepsis in a tertiary maternal & child care hospital in southern China. Vancomycin, teicoplanin and linezolid may be the best choice to management of neonatal sepsis.

Neonatal sepsis due to coagulase-negative staphylococci

Neonates, especially those born prematurely, are at high risk of morbidity and mortality from sepsis. Multiple factors, including prematurity, invasive life-saving medical interventions, and immaturity of the innate immune system, put these infants at greater risk of developing infection. Although advanced neonatal care enables us to save even the most preterm neonates, the very interventions sustaining those who are hospitalized concurrently expose them to serious infections due to common nosocomial pathogens, particularly coagulase-negative staphylococci bacteria (CoNS). Moreover, the health burden from infection in these infants remains unacceptably high despite continuing efforts. In this paper, we review the epidemiology, immunological risk factors, diagnosis, prevention, treatment, and outcomes of neonatal infection due to the predominant neonatal pathogen CoNS.

Neonatal immune adaptation of the gut and its role during infections

The intestinal tract is engaged in a relationship with a dense and complex microbial ecosystem, the microbiota. The establishment of this symbiosis is essential for host physiology, metabolism, and immune homeostasis. Because newborns are essentially sterile, the first exposure to microorganisms and environmental endotoxins during the neonatal period is followed by a crucial sequence of active events leading to immune tolerance and homeostasis. Contact with potent immunostimulatory molecules starts immediately at birth, and the discrimination between commensal bacteria and invading pathogens is essential to avoid an inappropriate immune stimulation and/or host infection. The dysregulation of these tight interactions between host and microbiota can be responsible for important health disorders, including inflammation and sepsis. This review summarizes the molecular events leading to the establishment of postnatal immune tolerance and how pathogens can avoid host immunity and induce neonatal infections and sepsis.