A 30-year perspective of low-dose dexamethasone, a single dose of mannitol and antiseizures prophylaxis on the prognosis of pneumococcal meningitis.

OBJECTIVES: This study details the accumulated experience of more than 31 years using a low-dose systematic dexamethasone protocol with mannitol and antiseizure prophylaxis for the treatment of suspected pneumococcal meningitis. METHODS: Data have been prospectively collected for the period1977-2018. From 1987, patients with suspected pneumococcal meningitis received 12 mg dexamethasone followed by 4 mg/6 h for 48 h, started before or with the first antibiotic dose. They also received (1) a single intravenous dose of 0.5-1 g/Kg mannitol, and (2) antiseizure prophylaxis with phenytoin. RESULTS: In total, 363 episodes of pneumococcal meningitis were recorded. Of these, 242 were treated with the dexamethasone protocol after 1987 and 121 were treated without the protocol. Overall mortality was 11.6% (28/242) among patients treated with dexamethasone and 35% (43/121) among those treated without dexamethasone (p = 0.000). Early mortality was significantly lower at 5.8% (14/242) with dexamethasone and 24% (29/121) without dexamethasone (p = 0.000). Finally, neurological mortality was significantly lower at 7.4% (18/242) with dexamethasone and 23% (28/121) without dexamethasone (p = 0.000). CONCLUSIONS: A low dose of dexamethasone along with a single dose of mannitol and antiseizures prophylaxis might be useful for reducing both overall and early mortality in pneumococcal meningitis in adult patients.

Penicillin- and Cephalosporin-Resistant Pneumococcal Meningitis: Treatment in the Real World and in Guidelines.

To report on the therapy used for penicillin- and cephalosporin-resistant pneumococcal meningitis, we conducted an observational cohort study of patients admitted to our hospital with pneumococcal meningitis between 1977 and 2018. According to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations, we defined pneumococci as susceptible and resistant to penicillin with MIC values of ≤0.06 mg/L and > 0.06 mg/L, respectively; the corresponding values for cefotaxime (CTX) were ≤0.5 mg/L and >0.5 mg/L. We treated 363 episodes of pneumococcal meningitis during the study period. Of these, 24 had no viable strain, leaving 339 episodes with a known MIC for inclusion. Penicillin-susceptible strains accounted for 246 episodes (73%), penicillin-resistant strains for 93 (27%), CTX susceptible for 58, and CTX resistant for 35. Nine patients failed or relapsed and 69 died (20%), of whom 22% were among susceptible cases and 17% were among resistant cases. During the dexamethasone period, mortality was equal (12%) in both susceptible and resistant cases. High-dose CTX (300 mg/Kg/day) helped to treat failed or relapsed cases and protected against failure when used as empirical therapy (P = 0.02), even in CTX-resistant cases. High-dose CTX is a good empirical therapy option for pneumococcal meningitis in the presence of a high prevalence of penicillin and cephalosporin resistance, effectively treating pneumococcal strains with MICs up to 2 mg/L for either penicillin or CTX.

Community-acquired bacterial meningitis in elderly patients: experience over 30 years.

Clinical characteristics, etiologies, evolution, and prognostic factors of community-acquired bacterial meningitis in elderly patients are not well known. To improve this knowledge, all episodes of community-acquired bacterial meningitis were prospectively recorded and cases occurring in patients >or=65 years old were selected. During the period 1977-2006, 675 episodes in adults (aged >or=18 yr) were recorded, with 185 (27%) in patients aged >or=65 years old; 76 were male and 109 were female, with a mean age of 73 +/- 6 years (range, 65-93 yr). Causative microorganisms were Streptococcus pneumoniae 74, Neisseria meningitidis 49, Listeria monocytogenes 17, other streptococcal 9, Escherichia coli 6, Haemophilus influenzae 4, Klebsiella pneumoniae and Staphylococcus aureus 2 each, Capnocytophaga canimorsus and Enterococcus faecalis 1 each, and unknown in 20. On admission 91% had had fever, 32% were in a coma (Glasgow Coma Scale or=65 yr), who showed a higher frequency of diabetes and malignancy as underlying disease; pneumonia, otitis, and pericranial fistula as predisposing factors; and S. pneumoniae and L. monocytogenes as etiology. There were also differences in clinical presentation, complications, sequelae, and mortality. Factors independently related with mortality were age, pneumonia as a predisposing factor, coma on admission, and heart failure and seizures after therapy. Dexamethasone therapy was a protective factor. In conclusion, bacterial meningitis in elderly patients is associated with greater diagnostic difficulties and neurologic severity and more complications, as well as with increased mortality. Antiseizure prophylaxis might be useful in these patients.

Evaluation of antimicrobial regimens in a guinea-pig model of meningitis caused by Pseudomonas aeruginosa.

To compare the efficacy of meropenem, ceftazidime, tobramycin and ceftazidime+tobramycin in a guinea-pig model of P. aeruginosa meningitis. After anesthesia, the atlanto-occipital membrane was punctured with a butterfly needle and 100 microl of a solution containing 10(6)CFU/ml of P. aeruginosa were injected directly into the cisterna magna. Four h later, therapy was initiated with saline or antibiotics given im for 48 h in doses that obtained CSF levels as in human meningitis: ceftazidime 200 mg/kg/8h, meropenem 200 mg/kg/8h, tobramycin 30 mg/kg/24h. Tobramycin was also given intracisternally. Animals were sacrificed at different time points. CSF and blood samples were collected and a meningeal swab was performed. Four hours after inoculation, bacterial concentration in CSF was 4 to 5log10CFU and mean WBC was 16,000/-l. All control animals died in 24h with a 12% increase in cerebral edema. All blood-cultures were negative. Ceftazidime, ceftazidime+tobramycin and meropenem reduced the CSF bacterial concentration at 8h by 2.5log10. At 48 h all CSF cultures were sterile but meningeal swab cultures remained positive in 30%. Our results suggest that meropenem may be at least as effective as ceftazidime and that the addition of tobramycin to ceftazidime may improve its efficacy.

West Nile virus in Spain: report of the first diagnosed case (in Spain) in a human with aseptic meningitis.

We report the first case of illness caused by West Nile virus (WNV) so far diagnosed in Spain. A 21-y-old male presented with clinical and biological signs compatible with viral meningitis. Acute and convalescent serum samples showed IgM and IgG positivity for WNV. These results were confirmed by microneutralization assays.

[Experimental meningitis due to a high-level cephalosporin-resistant strain of Streptococcus pneumoniae serotype 23F]. / Meningitis experimental producida por una cepa de Streptococcus pneumoniae serotipo 23F con elevada resistencia a cefalosporinas.

INTRODUCTION: The increasing prevalence of high-level cephalosporin-resistant strains of Streptococcus pneumoniae could complicate the treatment of severe infections such as meningitis. There are still questions as to the characteristics of these strains, their ability to produce severe infection, and the inflammatory response they induce in CSF. METHODS: Using a rabbit model of meningitis, we sought to determine the pathogenicity and differences in inflammatory parameters in two serotype 23F S. pneumoniae strains with different susceptibility to betalactams. Minimal inhibitory concentrations of the two strains were as follows: strain A--PEN 4 micro g/mL, CRO/CTX 2 micro g/mL--and strain B--PEN 0.12 micro g/mL, CRO/CTX 32 micro g/mL. RESULTS: Strain A resulted in a greater incidence of secondary bacteremia and higher inflammatory parameters during the early phases of infection. Strain B caused brain edema, a more severe inflammatory response and significantly higher mortality at the end of the experiment. CONCLUSIONS: Both strains induced meningitis in the animal model. The differences in inflammatory response produced by the two strains could be related to the variations that determine the betalactam resistance level.

Enterococcal meningitis: a clinical study of 39 cases and review of the literature.

To describe the clinical features and outcome of enterococcal meningitis, we retrospectively reviewed the charts of 39 cases seen at 2 tertiary hospitals during a 25 years and collected 101 additional, previously reported cases for review. Among these 140 cases, there were 82 cases (59%) of postoperative meningitis and 58 cases (41%) of spontaneous meningitis. Eighty-six patients (61%) were adults and 54 (39%) were children. Patients with spontaneous meningitis had a higher frequency of community-acquired infection (50% versus 18%; p < 0.01), severe underlying diseases (67% versus 22%; p < 0.01), and associated enterococcal infection (29% versus 8%; p < 0.01) than patients with postoperative meningitis. The clinical presentation was similar in both groups, but patients with spontaneous infection had a higher frequency of bacteremia (58% versus 12%; p < 0.01), and a lower frequency of mixed infection (9% versus 29%; p < 0.01). Spontaneous meningitis in children was associated with a significantly lower frequency of fever, altered mental status, headache, and meningeal signs (p < 0.01), probably explained by the high proportion of neonates in this age-group. Most infections were caused by Enterococcus faecalis, which accounted for 76% of the isolates identified at the species level. Fifteen of the 25 cases due to Enterococcus faecium were produced by vancomycin-resistant strains. Most patients were treated with ampicillin, penicillin, or vancomycin, with or without aminoglycosides, for a median period of 18 days (range, 1-85 d). Overall mortality was 21%. The mortality rate was higher in spontaneous than in postoperative meningitis (33% versus 12%; p < 0.01), but was similar in patients treated with beta-lactams (18%), glycopeptides (14%), or other antibiotics (25%), as well as in patients treated with monotherapy (16%) or combination therapy (22%). An adverse outcome correlated significantly with advanced age, the presence of severe underlying diseases, associated enterococcal infection, bacteremia, septic shock, and the absence of fever at presentation. Shunt removal was associated with a lower mortality. Multivariate analysis showed that the presence of severe underlying diseases was the only prognostic factor associated with mortality (odds ratio = 6.8, 95% confidence intervals = 2.7-17.5, p < 0.01).

Experimental study of LY333328 (oritavancin), alone and in combination, in therapy of cephalosporin-resistant pneumococcal meningitis.

Using a rabbit model of meningitis, we sought to determine the efficacy of LY333328, a semisynthetic glycopeptide, in the treatment of cephalosporin-resistant pneumococcal meningitis. LY333328 was administered at a dose of 10 mg/kg of body weight/day, alone and in combination with ceftriaxone at 100 mg/kg/day with or without dexamethasone at 0.25 mg/kg/day. The therapeutic groups were treated with LY333328 with or without dexamethasone and LY333328-ceftriaxone with or without dexamethasone. Rabbits were inoculated with a cephalosporin-resistant pneumococcal strain (ceftriaxone MIC, 2 microg/ml; penicillin MIC, 4 microg/ml; LY333328 MIC, 0.008 microg/ml) and were treated over a 26-h period beginning 18 h after inoculation. The bacterial counts in cerebrospinal fluid (CSF), the white blood cell count, the lactic acid concentration, the CSF LY333328 concentration, and bactericidal and bacteriostatic activities were determined at different time points. In vitro, LY333328 was highly bactericidal and its use in combination with ceftriaxone at one-half the MIC was synergistic. In the rabbit model, LY333328 alone was an excellent treatment for cephalosporin-resistant pneumococcal meningitis, with a rapid decrease in colony counts and no therapeutic failures. The use of LY333328 in combination with ceftriaxone improved the activity of LY333328, but no synergistic effect was observed. The combination of LY333328 with dexamethasone was also rapidly bactericidal, but two therapeutic failures were observed. The combination of LY333328 with ceftriaxone and dexamethasone was effective, without therapeutic failures.