Report of two cases of aseptic meningitis with persistence of pneumococcal cell wall components in cerebrospinal fluid after Pneumococcal meningitis.

We describe two cases of aseptic meningitis occurring some time after pneumococcal meningitis. Both cases may have resulted from an inflammatory response to persistent pneumococcal cell membrane components, as the cerebrospinal fluid samples were positive by the Binax NOW Streptococcus pneumoniae antigen test. Potential mechanisms and diagnostic impact are discussed.

Detecting polysaccharide antigen of Neisseria meningitidis group C in cerebrospinal fluid by dot-ELISA assay.

Cerebrospinal fluid (CSF) samples from 210 patients (200 with clinical evidence of bacterial meningitis, 10 with other clinical neurologic disease) were tested by a Dot-ELISA assay for detection of polysaccharide antigen of N. meningitidis group C. CSF samples were treated with EDTA 0.1 M, at pH 7.5 and heated to 90>C for 10 min. Polyclonal antiserum was purified by use of ethanol fractionation. The results were compared to those using bacterial culture (BC), latex agglutination (LA), counterimmunoelectrophoresis (CIE), and direct microscopy (DM) methods. Test results showed a correlation of 93.3%, 94.3%, 91.0% and 69.5% respectively, and sensitivity of 0.947 and specificity of 0.930. This study suggests that the dot-ELISA assay of CSF is a useful alternative technique for the diagnosis of group C meningitis.

Lower lipoteichoic and teichoic acid CSF concentrations during treatment of pneumococcal meningitis with non-bacteriolytic antibiotics than with ceftriaxone.

In the rabbit model of Streptococcus pneumoniae meningitis, treatment with rifabutin, quinupristin-dalfopristin, moxifloxacin and trovafloxacin led to smaller increases of the CSF concentrations of the pro-inflammatory cell wall components lipoteichoic and teichoic acids (LTA and TA) than did treatment with ceftriaxone. Low doses of moxifloxacin were associated with higher LTA and TA concentrations in CSF than were high doses.

Enhancement of HIV type 1 infectivity in vitro by capsular polysaccharide of Cryptococcus neoformans and Haemophilus influenzae.

High concentrations of the cryptococcal capsular polysaccharide (CCP) are present in the serum, cerebrospinal fluid or both in the majority of AIDS patients infected with Cryptococcus neoformans. Because the prognosis of AIDS patients infected with cryptococcus is poor, we investigated whether the presence of CCP enhanced HIV-1 infection. The presence of CCP markedly increased the infectivity of HIV-1-infected H9 cells and subsequent production of infectious HIV-1 and formation of syncytia. In addition to enhancing the infectivity of H9 cells infected with laboratory isolates of HIV-1, the presence of CCP also increased the infectivity of peripheral blood mononuclear cells (PBMCs) infected with primary field strains of HIV-1. The in vitro infectivity of PBMCs from 20 of 44 HIV-1-infected individuals was significantly increased when cultured with CCP. Furthermore, HIV-1 was isolated from the PBMCs of three of these individuals only when cultured in the presence of CCP. CCP increased the binding of HIV-1 and recombinant gp120 to H9 cells and recombinant CD4, respectively. Thus, it is possible that the enhancement of HIV-1 infectivity by CCP is due to its capacity to increase the adherence of HIV-1 to target cells. Whereas the capsular polysaccharide of Haemophilus influenzae also markedly enhanced the infectivity of HIV-1, the capsular polysaccharides of C. freundii or S. flexneri had minimal effects on the infectivity of HIV-1. This indicated that the capacity to enhance HIV-1 infectivity was a property of polysaccharides from some pathogens and not others.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemophilus influenzae type b lipooligosaccharide induces meningeal inflammation.

We evaluated the ability of two Haemophilus influenzae type b (Hib) components, lipooligosaccharide (LOS) and capsular polysaccharide, to provoke meningeal inflammation in rabbits. Intracisternal inoculation of 2 fg-200 ng of LOS produced a dose-dependent increase in concentrations of white blood cells and protein in cerebrospinal fluid, whereas 4 micrograms of Hib capsular polysaccharide did not provoke meningeal inflammation. Preincubation of LOS with a murine monoclonal antibody to Hib LOS did not reduce the potency of the LOS. Incubation of LOS with polymyxin B (which neutralizes LOS by binding to its lipid A region) and deacylation of the LOS with acyloxyacyl hydrolase (a neutrophil enzyme that removes nonhydroxylated fatty acyl chains from lipid A) reduced meningeal inflammation. We demonstrated that purified Hib LOS induced meningeal inflammation in this model and suggest that the lipid A moiety of Hib LOS is principally responsible for this host response.

Quantitation of Haemophilus influenzae serotype b capsular polysaccharide antigen in body fluids by enzyme immunoassay.

A heterogeneous enzyme immunoassay (EIA) has been developed to quantify capsular polysaccharide antigen of Haemophilus influenzae serotype b (Hib) polyribosyl - polyribitol -phosphate (PRP) in body fluids. Anti-Hib immunoglobulin G form rabbit adsorbed to the solid phase reacts with PRP existing in free soluble form in cerebrospinal fluid, serum or urine during Hib infection. IgG-anti-Hib labelled with horseradish peroxidase then links to PRP; the enzyme activity is measured by oxidation of the chromogenic substrate o-phenylenediamine. PRP concentrations ranged between 2 micrograms/1 to 21 mg/1 detected in acute Hib disease. The applicability of the EIA as a diagnostic aid is limited by cross-reaction of other bacterial antigens. However, quantitative measurements of PRP by enzyme immunoassay should improve studies on Hib disease.

Sensitivity of commercial agglutination and counterimmunoelectrophoresis methods for the detection of Haemophilus influenzae Type b capsular polysaccharide.

Comparison testing of commercial latex agglutination, coagglutination, and counterimmunoelectrophoresis (CIE) reagents for the detection of Haemophilus influenzae Type b capsular antigen in cerebral spinal fluid was performed. Latex agglutination was the most sensitive (0.2 ng/mL), followed by coagglutination (10 ng/mL), and CIE (20 ng/mL). In addition, the commercial antisera for CIE failed to react with high concentrations of capsular antigen, well within the range found during the course of meningitis.

Antigen detection in cerebrospinal fluid--pros and cons.

Over the past decade, rapid diagnostic techniques for detection of bacterial polysaccharide antigens have been developed and successfully applied in the clinical setting. Currently, countercurrent immunoelectrophoresis, latex particle agglutination, and coagglutination are the techniques most used in microbiology laboratories. Enzyme immunoassays may become more practical in the future. Quantitation of antigen concentration in cerebrospinal fluid provides prognostic information at the time of admission. This review summarizes the advantages, disadvantages, and clinical applications of these techniques.

Clinical studies of a new latex particle agglutination test for detection of Haemophilus influenzae type b polyribose phosphate antigen in serum, cerebrospinal fluid, and urine.

A new latex particle agglutination test for direct detection of Haemophilus influenzae type b polyribose phosphate antigen in serum, cerebrospinal fluid, or urine was evaluated from studies at four clinical centers. Although use of a serum buffer significantly reduced inconclusive agglutination of the latex particles, the retesting of serum samples, after heat inactivation and dilution, resolved all serum samples, with one exception, as reactive or nonreactive for the presence of the polyribose phosphate antigen. A clinical accuracy of 100% was obtained for the latex particle agglutination method in respect to its capability for detection of polyribose phosphate antigen in all patients with confirmed infection by H. influenzae type b.

Rapid diagnosis of bacterial meningitis.

The diagnostic value of several investigations which may demonstrate bacteria or bacterial products in cerebrospinal fluid (CSF) samples from patients with meningitis are discussed. Estimation of CSF lactate and lactate dehydrogenase levels was found to be of value in the differential diagnosis of viral, bacterial and fungal meningitis and the detection of endotoxin by the Limulus amoebocyte lysate test was shown to be strongly suggestive of Gram-negative meningitis. The demonstration of bacterial capsular polysaccharides in CSF by counterimmuno-electrophoresis, latex agglutination and ELISA was of value in establishing a precise aetiological diagnosis, but the usefulness of these methods was limited by the lack of general availability of specific high-potency antisera which determine the sensitivity of the procedure. These screening tests do not replace standard analysis of CSF but provide useful ancillary evidence of meningitis. Negative results obtained from screening tests should not exclude a diagnosis of bacterial meningitis and a decision to withhold treatment should only be made after all available CSF results are evaluated in conjunction with the clinical features.

Enzyme immunoassay of the capsular polysaccharide of Streptococcus pneumoniae type III in cerebrospinal fluid in experimental meningitis.

An enzyme immunoassay (EIA) for the capsular polysaccharide of Streptococcus pneumoniae type III was developed and applied to the measurement of this antigen in cerebrospinal fluid (CSF) in an experimental model of pneumococcal meningitis. EIA was performed by a single-antibody sandwich technique in which the globulin fraction of pneumococcal type-specific antiserum (antiserum-globulin) was used to coat the solid phase before antigen attachment and to conjugate with the labelling enzyme, horseradish peroxidase. Under optimum assay conditions EIA detected purified pneumococcal type-III capsular polysaccharide in concentrations as low as 0.15 ng/ml in aqueous buffer. Assayed by EIA, the mean concentration of type-III capsular polysaccharide in CSF of rabbits with pneumococcal meningitis increased exponentially from 24 h to 96nh of infection (range 13.9 ng/ml--62 500 ng/ml). Effective antimicrobial therapy of rabbits with meningitis was associated with a rapid decrease in the CSF concentration of the capsular antigen, although it was still detected in concentration in the range 1--10 ng/ml in 100% of animals treated for 4 days. Thus EIA provides a quantitative and extremely sensitive method of measuring type-III pneumococcal capsular polysaccharide in CSF.