Neonatal bacterial sepsis

A study of elevated red cell distribution width (RDW) in early-onset neonatal sepsis

Background

Neonatal sepsis is a serious infection occurring within the first 28 days of life. It is a significant cause of mortality and morbidity. Red cell distribution width (RDW) is estimated within the standard CBC profile and considered a simple tool for the diagnosis of neonatal sepsis without additional cost. Our aim in this study is to investigate the potential role of red cell distribution width (RDW) in the diagnosis of early-onset neonatal sepsis (EONS). The aim of our study is to detect the role of red cell distribution width (RDW) in the diagnosis and prognosis of early-onset neonatal sepsis (EONS).

Results

This case-control study was conducted at the NICU of Beni-Suef University Hospital and revealed that RDW% was highly significantly higher among cases than among controls (16.65 ± 4.28, 11.13 ± 0.62, respectively); regarding the severity of neonatal sepsis, we divided our cases into three groups (sepsis group includes 21 neonates, severe sepsis group includes 31 neonates, and septic shock group includes 48 neonates), there were statistically significant differences between the three groups (sepsis, severe sepsis, and septic shock) regarding RDW (15.15 ± 1.65, 16.78 ± 2.01, 17.02 ± 2.02, respectively) as P value (0.027).

Conclusion

This study revealed that RDW is associated with the diagnosis and prognosis of early-onset neonatal sepsis, so further study is needed to prove causation as it is being simple, less expensive, available, and easily repeated as it is routinely done with CBC, so it will be a good indicator for prognosis of neonatal sepsis.

Epidemiology of group B streptococcus in Korean pregnant women

Between January 2006 and May 2008, 2624 pregnant S. Korean women between 35–37 weeks gestation were screened for group B streptococcus (GBS). Resistance to antimicrobials was tested by disk diffusion and serotype determined using co-agglutination assays and microarray methods. Overall, 8% of pregnant women were colonized. Serotype III was the predominant serotype (43·8%), followed by serotypes V (20·3%), Ia (12·1%), and Ib (9·5%). GBS was frequently resistant to clindamycin (54·0%) and erythromycin (25·6%); 3·7% were resistant to cefazolin. More than three-quarters of serotype V were resistant to clindamycin or erythromycin or both, and 71% of serotype III were resistant to clindamycin but only 12% were resistant to erythromycin. GBS prevalence exceeded earlier reports by one-third. This is the first report of cefazolin resistance in Korea. These results underscore the need to establish screening measures and chemoprophylaxis guidelines regarding GBS infections in Korea.

Epidemiology of neonatal sepsis in South Korea

BACKGROUND

Neonatal sepsis is a severe clinical syndrome characterized by systemic signs of infection, shock and system organ failure; diagnosis is confirmed on positive culture from a normally sterile site(s). There are few reports comparing incidence, mortality, and risk factors between clinically diagnosed sepsis and that confirmed by culture.

METHODS

All infants diagnosed with early- (within first 72 h after birth) or late-onset (72 h-4 weeks after birth) neonatal sepsis between 1997 and 1999 from four neonatal centers in South Korea, were investigated.

RESULTS

The estimated incidence rate of neonatal sepsis during the 3 years was 30.5 per 1000 live births for clinical sepsis and 6.1 per 1000 live births for sepsis with positive culture, with case-fatality rates of 4.7% and 2.2%, respectively. When only early-onset sepsis was considered, the incidence and fatality rates were 25.1 per 1000 live births and 6.1% for clinical sepsis, and 4.3 per 1000 live births and 2.5% for culture-confirmed sepsis, respectively. For the 179 patients (185 causative organisms) of proven sepsis, Staphylococcus spp. including S. aureus were the most frequent isolates. In early-onset clinical sepsis, having very low birthweight (<or=1500 g), a low Apgar score at 5 min (<or=7), and being male were related to higher rates of case-fatality (relative risk: 11.3, 6.8 and 2.5, respectively).

CONCLUSIONS

Clinical sepsis was more common than culture-confirmed sepsis and had a higher case-fatality rate. It seems prudent to take rapid and decisive steps toward better management of the high-risk group whether the sepsis is clinically diagnosed or culture confirmed.

Neuroprotective role of minocycline in co-cultures of human fetal neurons and microglia

Bacterial infections during pregnancy often result in premature birth and neonatal white matter damage. During these infections, microglia, the resident immune cells of the CNS, undergo activation and contribute to further neuronal damage of the CNS. Minocycline, a second-generation tetracycline antibiotic, inhibits microglial activation and protects neurons in rodents but data about its effects on human cells are limited. We studied the mechanism of the neuroprotective effect of minocycline in either purified cell cultures or co-cultures of microglia and neurons from human fetal brain during inflammation induced by lipopolysaccharide (LPS). In neuron/microglial co-cultures, minocycline treatment prevented activation and proliferation of microglia and protected neurons as demonstrated by decreased neuronal cell death and a shift of Bcl-2 family proteins toward anti-apoptotic ratio. Notably, neither minocycline nor LPS had an effect on neurons in purified neuronal cultures. The ability of minocycline to regulate activation of human fetal microglia might be relevant in therapies used towards treating neonatal CNS infections.

Sepsis in 2003: are we still in the middle of nowhere?

PURPOSE OF REVIEW

Although enthusiasm of intensivists has been raised during the last 2-3 years due to several successful clinical trials, severe sepsis and septic shock still have an increasing incidence with more or less unchanged mortality. Within the last 12 months, the progress in sepsis research covering definitions, epidemiology, pathophysiology, diagnosis, standard and adjunctive therapy, as well as experimental approaches is encouraging. In this review, state-of-the-art publications of 2003 are presented to elucidate the possible impact on clinical routine.

RECENT FINDINGS

The rationale for using a new definition based on the PIRO system has been widely acknowledged, although it is not yet applicable in clinical practice. This includes genomic information for stratifying subgroups of patients, and a broader field of laboratory diagnostics due to clinical studies and basic research on the cellular mechanisms of inflammation and organ dysfunction. Early diagnosis is important for a fast implementation of specific therapies, and it has been confirmed that the time until the start of therapy has an impact on patient outcome. Thorough data analysis of successful trials with activated protein C has revealed encouraging details on long-term outcome and subgroup effects. Together with new findings on low-dose hydrocortisone, this stresses the relevance of adjunctive therapy in severe sepsis and septic shock.

SUMMARY

Scientific progress in areas of sepsis has been continuing throughout 2003, although the challenges are still enormous. The identification of more specific markers and new therapeutic approaches will hopefully improve the diagnosis, monitoring of therapy, and outcome in the septic patient.

Monocyte toll-like receptor 4 expression and LPS-induced cytokine production increase during gestational aging

Premature newborns are highly susceptible to severe bacterial infections. This is partially due to their immature innate immune system, characterized by decreased neutrophil and monocyte activity as well as by reduced concentrations of complement factors. However, additional mechanisms might be important for innate immunity and are still the subject of considerable debate. The importance of pattern recognition domains such as Toll-like receptors (TLR) has been fully acknowledged within the last few years. Therefore, we investigated age-related monocyte TLR4 expression and lipopolysaccharide-induced cytokine secretion from very low birth weight infants (VLBWI) and from newborns after wk 30 of gestation in comparison to healthy adults. In VLBWI, expression of TLR4 surface protein, detected by flow cytometry, and TLR4-specific mRNA, quantified by real time-PCR, were significantly reduced in comparison to mature infants and to adults. Reduced TLR4 expression was paralleled by significantly diminished ex vivo LPS stimulated IL-1beta, IL-6, and tumor necrosis factor-alpha secretion into whole blood. We conclude that, in VLBWI, the minimized expression of TLR4 contributes to the susceptibility of VLBWI to infections with Gram-negative bacteria due to the lack of cytokines to boost initial immune response.