Recent advances in management of bacterial meningitis in neonates

Utilization of serologic assays to support efficacy of vaccines in nonclinical and clinical trials: meeting at the crossroads

In May 2009 the National Institute of Allergy and Infectious Diseases hosted a workshop on serologic assays that support vaccine efficacy evaluations. The meeting promoted exchange of ideas among investigators from varying disciplines who are working on anti-infectious agent vaccines at different stages of development. The presentations and discussions at the workshop illustrated the challenges common across various pathogens with recurring themes: (1) A thorough understanding of the science regarding the pathogen and the host response to disease and immunization is fundamental to assay selection. (2) The intended use of the immunoassay data must be clearly defined to ensure appropriate specificity, accuracy, and precision; a laboratory must also commit resources to assure data quality and reliability. (3) During vaccine development, an immunoassay may evolve with respect to quality, purpose, and degree of standardization, and, in some cases, must be changed or replaced as data are accumulated. (4) Collaboration on standardized reagents and methods, harmonization efforts, and multidisciplinary teams facilitate consistent generation of quality data. This report provides guidance for effective development and utilization of immunoassays based on the lessons learned from currently licensed vaccines. Investigators are encouraged to create additional opportunities for scientific exchange, noting that the discussed themes are relevant for immunoassays used for other purposes such as therapeutics and diagnostics.

TRPV4 enhances the cellular uptake of aminoglycoside antibiotics

The cochlea and kidney are susceptible to aminoglycoside-induced toxicity. The non-selective cation channel TRPV4 is expressed in kidney distal tubule cells, and hair cells and the stria vascularis in the inner ear. To determine whether TRPV4 is involved in aminoglycoside trafficking, we generated a murine proximal-tubule cell line (KPT2) and a distal-tubule cell line (KDT3). TRPV4 expression was confirmed in KDT3 cells but not in KPT2 cells. Removal of extracellular Ca(2+) significantly enhanced gentamicin-Texas-Red (GTTR) uptake by KDT3, indicative of permeation through non-selective cation channels. To determine whether TRPV4 is permeable to GTTR, stable cell lines were generated that express TRPV4 in KPT2 (KPT2-TRPV4). KPT2-TRPV4 cells took up more GTTR than control cell lines (KPT2-pBabe) in the absence of extracellular Ca(2+). TRPV4-dependent GTTR uptake was abolished by a point mutation within the crucial pore region of the channel, suggesting that GTTR permeates the TRPV4 channel. In an endolymph-like extracellular environment, clearance of GTTR was attenuated from KPT2-TRPV4 cells in a TRPV4-dependent fashion. We propose that TRPV4 has a role in aminoglycoside uptake and retention in the cochlea.

Clinical immunology and infectious diseases

Without the application of immunology, understanding of the pathogenesis and pathophysiology of infectious diseases would be severely retarded. The development new vaccines for the prevention of infectious diseases has been based on new immunologic findings. Immunodiagnostic modalities have provided for the growth of diagnostic techniques for infectious diseases. Clinical immunology also has laid the groundwork for immunotherapies using the old intravenous immunoglobulin preparations and the new monoclonal antibodies, cytokines, and interferons.

The changing spectrum of neonatal meningitis over a fifteen-year period

One hundred seventy-seven cases of neonatal meningitis treated at the University of Texas Medical Branch at Galveston over a 15-year period (1974-1988) were reviewed. Over this period, the incidence of bacterial meningitis decreased, the incidence of aseptic meningitis remained stable, and the diagnosis of enteroviral meningitis increased in frequency. During 1984-1988, enterovirus was the most common cause of meningitis in neonates older than seven days and accounted for one third of all cases of neonatal meningitis. Half of all neonates with bacterial meningitis had negative blood cultures. We recommend that 1) diagnostic lumbar puncture remain part of the routine assessment of the neonate with suspected sepsis, and 2) CSF be cultured for enterovirus as well as for bacteria when a neonate older than seven days presents with suspected sepsis.

Meningitis in the newborn--a 14 year review

A 14 year review of meningitis in babies showed that overall mortality and survival without handicap has not improved. The failure to improve the prognosis of these babies during a period when overall perinatal mortality fell rapidly is because smaller babies are being affected and different organisms are being cultured.

The outcome of neonatal septicemia during fifteen years

The outcome of neonatal septicemia in 320 infants seen during 1969-83 has been evaluated. Mortality decreased from 27% to 12%. The incidence of moderate to severe handicaps in survivors remained unchanged at around 20%. Sixty percent of these handicapped children had meningitis or osteomyelitis, and many of these were healthy prior to onset. All handicapped infants without osteomyelitis or meningitis had several other risk factors that may have contributed to the final outcome.

Changing pattern of neonatal meningitis in Sweden. A comparative study 1976 vs. 1983

A nationwide retrospective epidemiological survey of neonatal meningitis in Sweden was performed in order to estimate possible changes in incidence, etiology and mortality. The total number of newborns with meningitis was 137 and 40 (29%) were preterm (less than 37 gestational weeks) infants and 27 of these preterm boys (20%). Meningitis from group B streptococci and Escherichia coli, the two major causative organisms in 1976, had decreased markedly in 1983. The identification rate of viral origin was more frequent during 1983 compared to 1976. The total incidence of meningitis was 8.9/10,000 livebirths in 1983 vs. 5.6/10,000 in 1976 but the rate of verified bacterial meningitis had decreased from 3.6/10,000 (1976) to 1.9/10,000 (1983). The total outcome was improved significantly since the combined mortality and handicap rates decreased from 34% in 1976 to 15% in 1983.