Attenuation of Cerebrospinal Fluid Inflammation by the Nonbacteriolytic Antibiotic Daptomycin versus That by Ceftriaxone in Experimental Pneumococcal Meningitis

Antibiotic-induced bacteriolysis exacerbates inflammation and brain damage in bacterial meningitis. Here the quality and temporal kinetics of cerebrospinal fluid (CSF) inflammation were assessed in an infant rat pneumococcal meningitis model for the nonbacteriolytic antibiotic daptomycin versus ceftriaxone. Daptomycin led to lower CSF concentrations of interleukin 1β (IL-1β), IL-10, IL-18, monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1 alpha (MIP-1α) (P < 0.05). In experimental pneumococcal meningitis, daptomycin treatment resulted in more rapid bacterial killing, lower CSF inflammation, and less brain damage than ceftriaxone treatment.Up to half of the survivors of pneumococcal meningitis are left with neurological sequelae, the rate of which remained unchanged over the last few decades despite continuous improvements in therapy (16). In patients and in corresponding experimental models, brain injury caused by bacterial meningitis has been shown to prominently affect three brain structures, the cortex, the hippocampus, and the inner ear (2, 6). The different forms of tissue damage represent the morphological correlate of the functional deficits observed in survivors, including cerebral palsy, deficits in learning and memory, and hearing loss (9, 12).Inflammation has been shown to play a key role in the pathophysiology leading to the development of brain damage consecutive to bacterial meningitis (11). Anti-inflammatory corticosteroids have been used as adjunctive therapy for bacterial meningitis, but conclusive evidence for a beneficial effect on brain damage, specifically in pediatric pneumococcal meningitis, is lacking (20). Prevention of the inflammatory reaction leads to less brain damage in experimental bacterial meningitis (14). Avoidance of the release of proinflammatory bacterial components upon use of nonbacteriolytic antibiotics is a promising strategic alternative to the use of corticosteroids (7, 14, 17). The nonbacteriolytic lipopeptide daptomycin was at least as efficient as ceftriaxone at eliminating bacteria from the cerebrospinal fluid (CSF) in experimental pneumococcal meningitis. Furthermore, daptomycin significantly lowered the CSF concentration of matrix-metalloproteinase 9 (MMP-9), an enzyme critically involved in the pathophysiology of brain damage, and in consequence caused less brain damage than ceftriaxone (7). Here we extended these observations by investigating the quality and temporal kinetics of CSF inflammation in infant rats with pneumococcal meningitis after treatment with daptomycin versus that with ceftriaxone.All animal studies were approved by the Animal Care and Experimentation Committee of the Canton of Bern, Switzerland, and followed the Swiss national guidelines for performance of animal experiments. Eleven-day-old Wistar rats (n = 28; Charles River, Germany) were injected intracisternally (i.c.) with 10 μl of saline containing 1.5 × 10⁴ CFU of Streptococcus pneumoniae (clinical isolate of a serotype 3 strain) as previously described (7, 10). Eighteen hours later, animals were randomly chosen to receive daptomycin (n = 14) (50 mg/kg body weight, administered subcutaneously [s.c.]; Cubicin, kindly provided by Cubist Pharmaceuticals, Lexington, MA) or ceftriaxone (n = 14) (100 mg/kg body weight given s.c.; Rocephine; Roche Pharma, Basel, Switzerland). The dosages of daptomycin and ceftriaxone used in this study are equal to those used in previously published work (7). Available data on pharmacokinetics/pharmacodynamics (PK/PD) of daptomycin in the CSF during experimental pneumococcal meningitis are derived from the rabbit model (3). For daptomycin, a comparable dosage in adult rats (40 mg/kg, s.c.) resulted in a maximum concentration of drug (C_max) and an area under the concentration-time curve from 0 to 24 h (AUC_0-24) in serum comparable to what is seen in humans with a 6- to 8-mg/kg dose given intravenously (i.v.) (15). More recently, a similar C_max was also obtained in adult mice after a dosage of 25 mg/kg given i.p. (13). Based on a comparable body weight of infant rats and adult mice of approximately 25 to 30 g, a 50-mg/kg dosage, adjusted for an increased metabolism in younger animals, is expected to lead to comparable serum levels of daptomycin. CSF samples were obtained by puncture of the cisterna at defined time points after infection, i.e., 18, 20, and 24 h (n = 7 for each treatment group) and 40 h (n = 7 for daptomycin and n = 8 for ceftriaxone) after infection. A control experiment with untreated animals was not performed, because excessive mortality is observed at these time points without antibiotic treatment. Bacterial killing was significantly more rapid by therapy with daptomycin than by that with ceftriaxone 2 h after the initiation of therapy. Four hours of daptomycin therapy decreased CSF bacterial titers below the detection limit (<10³ CFU/ml), leading to a more rapid sterilization of the CSF (see Fig. ​Fig.2A2A).Open in a separate windowFIG. 2.(A) CSF bacterial titers after antibiotic therapy. Sterilization of CSF was more rapid with therapy with daptomycin (DAP) than with therapy with ceftriaxone (CRO). Six hours after therapy, CSF was sterilized with daptomycin. At 2 and 4 h after therapy, bacterial titers differed significantly (P < 0.05, Mann-Whitney) between treatment groups. (B) Brain damage in experimental pneumococcal meningitis. The extent of cortical damage is significantly reduced (P = 0.02 Mann-Whitney) by daptomycin treatment versus that with ceftriaxone treatment. (C) Histopathology (overview). Cortical injury assessed by Nissl staining is characterized by wedge-shaped areas of decreased neuronal density (arrowheads), suggestive of ischemic necrosis (cresyl violet; original magnification, ×5; scale bar = 1 mm). (D) Histopathology. Focus of cortical neuronal loss (left side; arrowheads) containing neurons with morphological features of necrosis, including pyknotic nuclei, cell swelling, and fading of cytoarchitecture, is sharply demarcated from preserved brain tissue (right side; original magnification, ×200; scale bar, 50 μm; cresyl violet).The CSF concentrations of defined inflammatory mediators (interleukin 1β [IL-1β], IL-2, IL-6, IL-10, IL-18, tumor necrosis factor alpha [TNF-α], gamma interferon [IFN-γ], granulocyte-macrophage colony-stimulating factor [GM-CSF], chemokine [C-X-C motif] ligand 1 [CXCL1], macrophage inflammatory protein 1 alpha [MIP-1α], and monocyte chemoattractant protein 1 [MCP-1]) were assessed, using a microsphere-based multiplex assay (Lincoplex; Millipore Corporation) as described previously (5). The addition of 1, 10, or 100 μg/ml of daptomycin or ceftriaxone to a mixture of cyto- and chemokines at known concentrations had no effect on the performance and the results of immunoassay (data not shown). Statistically significant (P < 0.05) differences in the profiles of IL-1β, IL-10, IL-18, MCP-1, and MIP-1α protein expression were found between the two therapeutic modalities, as determined by two-way analysis of variance ANOVA (Fig. ​(Fig.1).1). Ceftriaxone led to a marked increase in the CSF concentration of the above-detailed cyto- and chemokines at 2 to 6 h after the initiation of therapy, while the reaction to daptomycin treatment was limited to a moderate increase in IL-18 only (Fig. ​(Fig.1).1). It has been shown that daptomycin does not exhibit an immunomodulatory effect in an experimental endotoxin model of human whole blood (19). It is therefore unlikely that the lower CSF levels of cyto- and chemokines with treatment with daptomycin is due to an anti-inflammatory activity of daptomycin by itself.Open in a separate windowFIG. 1.Profile of cyto-/chemokine concentration in the CSF for treatment with daptomycin versus that with ceftriaxone at different time points (2, 6, and 40 h) after initiation of therapy. The concentrations of IL-1β, IL-10, IL-18, MCP-1, and MIP-1α were significantly (P < 0.05, two-way ANOVA) lower in daptomycin-treated animals.For histopathological examination of brain damage, animals were sacrificed at 40 h after infection. Twelve coronal brain sections per animal were evaluated for neuronal injury of the cortex (Fig. 2C and D) and hippocampus, as described previously (5). The area of cortical necrosis was expressed as the percentage of the total area of cortex in each section, and the mean value per animal was calculated. Treatment with daptomycin versus that with ceftriaxone significantly reduced the occurrence (1/14 versus 6/14; P < 0.08, Fischer''s exact test) and severity of cortical damage (0.13% ± 0.5% versus 4.7% ± 8.8% of total cortical volume; n = 14 for each group; P = 0.03, Mann Whitney) (Fig. ​(Fig.2B).2B). Apoptosis in the dentate gyrus was not significantly different between the two treatment groups (data not shown).Daptomycin disrupts membrane functions of Gram-positive bacteria. It has also recently been shown to bind to YycG, interfering with the function of this key sensor kinase, leading to cell death without lysis (1). Accordingly, the release of [³H]choline from the cell wall of labeled bacteria was diminished in daptomycin-treated rabbits in comparison to results with ceftriaxone during experimental pneumococcal meningitis (18). In the present experimental model, treatment with daptomycin compared to that with ceftriaxone led to a more rapid decrease in CSF bacterial titers and a reduction in the occurrence of cortical neuronal injury (7). A decrease in the inflammatory reaction, as suggested by a significant difference in metalloprotease-9 activity 22 h after treatment, was proposed as a factor contributing to the improved outcome with daptomycin (7). In the present study, we extended these observations by focusing on the quality and temporal kinetics of the inflammatory reaction over 22 h after antibiotic therapy, a critical time with respect to the pathophysiological mechanisms leading to neuronal injury. From the 11 cyto- and chemokines measured, significantly lower concentrations of IL-1β, IL-10, IL-18, MCP-1, and MIP-1α were documented in the CSF of daptomycin-treated animals than in that of ceftriaxone-treated animals. Although not significant, CSF levels of IL-6, CXCL1, and TNF-α were also lower in daptomycin-treated animals.In a murine model, it has recently been shown that daptomycin and vancomycin, in combination with dexamethasone, were similarly active for the treatment of pneumococcal meningitis (13). The effect of dexamethasone was shown to only marginally affect the antibactericidal activity of daptomycin alone or in combination with ceftriaxone, although the penetration of daptomycin in the inflamed meninges was reduced (4).Successful treatment of a patient with methicillin-resistant Staphylococcus aureus with daptomycin has recently been reported (8). But because the activity of daptomycin is limited against Gram-positive bacteria, clinical use as an empirical therapy of bacterial meningitis would require combination with a broad-spectrum antibiotic. Sequential therapy with a nonlytic antibiotic, i.e., rifampin with ceftriaxone, has been recently demonstrated to cause less brain injury (17). Important in the context of a prospective clinical application is the recent finding that the combination of daptomycin with ceftriaxone was shown to be more active than vancomycin plus ceftriaxone in experimental rabbit meningitis (4). The present evidence supports further investigations of the use of daptomycin in combination therapy for bacterial meningitis and how it influences the inflammatory reaction and the development of neurological damage.     

Efficacy of Gatifloxacin in Experimental Escherichia coli Meningitis

The effectiveness of gatifloxacin therapy (15 mg/kg every 5 h [q5h]) was compared with that of meropenem (75 mg/kg q5h) and cefotaxime (75 mg/kg q5h) therapy in experimental meningitis caused by a beta-lactamase-producing strain of Escherichia coli. Gatifloxacin therapy was more rapidly bactericidal than cefotaxime but similar to meropenem therapy (bacterial killing rates at 5 h, 0.83 +/- 0.26, 0. 46 +/- 0.3, and 0.73 +/- 0.17 CFU/ml/h, respectively; P = 0.03 for gatifloxacin versus cefotaxime). At 10 h, seven of eight animals treated with gatifloxacin had <10 CFU/ml in their cerebrospinal fluid, compared with one of seven treated with cefotaxime therapy (P = 0.01). Gatifloxacin was at least as effective as currently available antibiotics in this model of E. coli meningitis.     

Moxifloxacin in the Therapy of Experimental Pneumococcal Meningitis

The activity of moxifloxacin (BAY 12-8039) against a Streptococcus pneumoniae type 3 strain (MIC and minimum bactericidal concentration [MBC] of moxifloxacin, 0.06 and 0.25 μg/ml, respectively; MIC and MBC of ceftriaxone, 0.03 and 0.06 μg/ml, respectively) was determined in vitro and in a rabbit model of meningitis. Despite comparable bactericidal activity, 10 μg of moxifloxacin per ml released lipoteichoic and teichoic acids less rapidly than 10 μg of ceftriaxone per ml in vitro. Against experimental meningitis, 10 mg of moxifloxacin per kg of body weight per ml reduced the bacterial titers in cerebrospinal fluid (CSF) almost as rapidly as ceftriaxone did (mean ± standard deviation, −0.32 ± 0.14 versus −0.39 ± 0.11 Δlog CFU/ml/h). The activity of moxifloxacin could be described by a sigmoid dose-response curve with a maximum effect of −0.33 ΔlogCFU/ml/h and with a dosage of 1.4 mg/kg/h producing a half-maximal effect. Maximum tumor necrosis factor activity in CSF was observed later with moxifloxacin than with ceftriaxone (5 versus 2 h after the initiation of treatment). At 10 mg/kg/h, the concentrations of moxifloxacin in CSF were 3.8 ± 1.2 μg/ml. Adjunctive treatment with dexamethasone at 1 mg/kg prior to the initiation of antibiotic treatment only marginally reduced the concentrations of moxifloxacin in CSF (3.3 ± 0.6 μg/ml). In conclusion, moxifloxacin may qualify for use in the treatment of S. pneumoniae meningitis.     

Rosaramicin Versus Penicillin G in Experimental Pneumococcal Meningitis

Rosaramicin, a new macrolide antibiotic, was compared with penicillin G in the treatment of pneumococcal meningitis in rabbits. Animals were infected intracisternally with 10(4) colony-forming units of Streptococcus pneumoniae type III (rosaramicin minimal inhibitory/bactericidal concentrations, 0.25/0.5 mug/ml; penicillin G minimal inhibitory/bactericidal concentrations, 0.03/0.06 mug/ml). Treatment was instituted 96 h later. Infusion of rosaramicin at 25 mg/kg per h intravenously for 8 h produced a peak cerebrospinal fluid (CSF) drug concentration of 1.54 mug/ml (range, 0.87-3.6 mug/ml). During this infusion the numbers of pneumococci in CSF decreased from 6.2 +/- 0.5 to 3.36 +/- 1.12 log(10) colony-forming units per ml. Penicillin G, infused at 30 mg/kg per h for 8 h, reached a similar concentration in CSF but caused a greater reduction (P < 0.01) in CSF bacteria, from 6.4 +/- 0.36 to 1.3 +/- 0.67 log(10) colony-forming units per ml. Penicillin G, at 100 mg/kg per day intramuscularly for 5 days, cured 7 of 10 rabbits with pneumococcal meningitis. A higher dose, 300 mg/kg per day for 5 days, was no more efficacious: 11 of 14 rabbits were cured. Rosaramicin at 100 mg/kg per day intramuscularly for 5 days cured only 5 of 15 rabbits with meningitis, but a higher dosage regimen of that drug (250 mg/kg per day intramuscularly) produced acute, fulminant enterocecitis and death within 48 h in seven of eight rabbits. No cytotoxin was detected in the feces of one rabbit with acute enterocecitis. Thus the efficacy of rosaramicin in experimental pneumococcal meningitis, measured by bacterial clearance from CSF and by treatment outcome, was less than that of penicillin G. In addition, high-dose parenteral rosaramicin caused acute, fulminant enterocecitis in a high proportion of treated rabbits.     

结核性脑膜炎脑脊液检测标志物研究进展

结核(Tuberculosis,TB)是最古老、最具破坏性的传染病之一,全球近三分之一的人感染了结核分枝杆菌(Mycobacterium tuberculosis,Mtb)。结核性脑膜炎是肺外结核的最严重形式,导致高致残率和致死率,约占全部结核病的1%。结核性脑膜炎(tuberculous meningitis,TBM)的早期诊断和治疗对预后至关重要。目前关于TBM实验室检查主要有脑脊液抗酸杆菌(acid‐fast bacillus,AFB)涂片、细菌培养、PCR技术及新型的抗原抗体检测等,本文对TBM脑脊液检测标志物研究进展做一综述。     

Bactericidal versus Bacteriostatic Antibiotic Therapy of Experimental Pneumococcal Meningitis in Rabbits

A rabbit model of pneumococcal meningitis was used to examine the importance of bactericidal vs. bacteriostatic antimicrobial agents in the therapy of meningitis 112 animals were infected with one of two strains of type III Streptococcus pneumoniae. Both strains were exquisitely sensitive to ampicillin, minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC)<0.125 μg/ml. The activity of chloramphenicol against the two strains varied: strain₁—MIC 2 μg/ml, MBC 16 μg/ml; strain₂—MIC 1 μg/ml, MBC 2 μg/ml. Animals were treated with either ampicillin or chloramphenicol in dosages that achieved a peak bactericidal effect in cerebrospinal fluid (CSF) for ampicillin against both strains. Two different dosages were used for chloramphenicol. The first dosage achieved a peak CSF concentration of 4.4±1.1 μg/ml that produced a bacteriostatic effect against strain₁ and bactericidal effect against strain₂. The second dosage achieved a bactericidal effect against both strains (mean peak CSF concentration 30.0 μg/ml). All animals were treated intramuscularly three times a day for 5 d. CSF was sampled daily and 3 d after discontinuation of therapy for quantitative bacterial cultures. Results demonstrate that only antimicrobial therapy that achieved a bactericidal effect in CSF was associated with cure. Over 90% of animals treated with one of the bactericidal regimens (i.e., animals in which the bacterial counts in CSF dropped >5 log₁₀ colony-forming units [cfu]/ ml after 48 h) had sterile CSF after 5 d of treatment. On the other hand, the regimen that achieved bacteriostatic concentrations (CSF drug concentrations between the MIC and MBC) produced a drop of 2.4 log₁₀ cfu/ml by 48 h; however, none of the animals that survived had sterile CSF after 5 d. These studies clearly demonstrate in a strictly controlled manner that maximally effective antimicrobial therapy of experimental pneumococcal meningitis depends on achieving a bactericidal effect in CSF.     

Effect of Experimental Pneumococcal Meningitis on Respiration and Circulation in the Rabbit

Pathophysiological studies in bacterial meningitis in man have been limited by clinical variability and the necessity for immediate therapy. After the development of a reliable animal model of pneumococcal meningitis, we studied respiration and circulation in 25 anesthetized New Zealand white rabbits during untreated pneumococcal meningitis and in 33 healthy controls. In meningitis, we found increased lactic acid in cerebrospinal fluid (CSF). Increased ventilation, perhaps due to CSF lactic acid accumulation, resulted in respiratory alkalosis; the concomitant lowering of Pco₂ acted as a homeostatic mechanism to restore pH toward normality in the CSF. Hyperventilation increased with the duration of the illness. Cardiac output was also increased with decreased peripheral vascular resistance but with only slight reduction in mean systemic and pulmonary arterial pressures. In the final hour of life, peripheral vascular resistance fell further; ventilation declined and then abruptly ceased while cardiac activity continued. Lactic acid accumulation in the CSF, found in both experimental and human pneumococcal meningitis, may cause the hyperventilation found in this disease and may contribute to death.     

The Pathophysiology of Pneumococcal Meningitis

The interactions between pneumoccocal surface components and host defence systems that initiate pneumoccocal meningitis have been studied in considerable molecular detail over the past decade. In this sense, the pneumococcus has served as a prototype for the unravelling of the genesis of inflammation caused by gram-positive bacteria. This review outlines the progression of these early events involving the cytokine cascade, the coagulation cascade, and leukocyte migration, and relates these processes to the production of blood-brain barrier permeability, the hallmark of injury in meningitis. This new understanding has radically altered the therapy of disease with the promise of greatly improved outcome.     

从病人脑脊液中分离出一株C群脑膜炎奈瑟双球菌

目的查明引起流脑流行菌群,为安徽省流脑预防与控制工作提供科学依据。方法采集流脑病人脑脊液用卵黄琼脂培养基直接分离,置37℃含5%～10%CO2条件下培养18～24h。结果分离培养出C群脑膜炎奈瑟双球菌,同时对密切接触者进行预防服药,有效地控制了疫情。结论为一步预防和控制疫情蔓延,应对当地18岁以下儿童进行流脑A+C疫苗接种。     

隐球菌脑膜炎患者脑脊液宏基因组二代测序结果分析

  目的  评价脑脊液宏基因组二代测序(metagenomic next-generation sequencing, mNGS)技术在隐球菌脑膜炎诊断中的潜在应用价值。  方法  回顾性收集北京协和医院2014年1月至2016年12月采用脑脊液mNGS技术辅助确诊的6例隐球菌脑膜炎患者临床资料, 包括脑脊液常规、生化、细胞学、培养、墨汁染色等实验室检测结果, 应用BGISEQ-100测序平台进行脑脊液病原测序, 综合分析患者的临床、实验室和辅助检查结果。  结果  6例患者中, 男性4例, 女性2例, 年龄26~53岁, 中位年龄51岁。6例患者均无免疫缺陷性疾病, 有头痛、脑膜刺激症状及颅内压增高表现, 5例患者出现发热, 2例患者出现复视。脑脊液常规检查示白细胞和蛋白轻度升高, 糖正常或轻度降低; 5例患者脑脊液墨汁染色阳性, 4例患者脑脊液隐球菌抗原检测阳性, 2例患者脑脊液真菌培养阳性。脑脊液mNGS检测隐球菌核酸序数为108~25 361, 基因覆盖率0.19%~29.00%;5例提示新型隐球菌感染, 其中3例经PCR检测证实为新型隐球菌感染; 1例提示格特隐球菌感染, 经生物质谱仪检测证实为格特隐球菌感染。  结论  脑脊液mNGS技术可准确判断隐球菌感染, 并对鉴别格特隐球菌具有一定优势, 有助于降低免疫功能正常人群隐球菌脑膜炎的漏诊率。     

Inhibition of Hippocampal Regeneration by Adjuvant Dexamethasone in Experimental Infant Rat Pneumococcal Meningitis

Pneumococcal meningitis (PM) causes neurological sequelae in up to half of surviving patients. Neuronal damage associated with poor outcome is largely mediated by the inflammatory host response. Dexamethasone (DXM) is used as an adjuvant therapy in adult PM, but its efficacy in the treatment of pneumococcal meningitis in children is controversially discussed. While DXM has previously been shown to enhance hippocampal apoptosis in experimental PM, its impact on hippocampal cell proliferation is not known. This study investigated the impact of DXM on hippocampal proliferation in infant rat PM. Eleven-day-old nursing Wistar rats (n = 90) were intracisternally infected with Streptococcus pneumoniae to induce experimental meningitis. Treatment with DXM or vehicle was started 18 h after infection, concomitantly with antibiotics (ceftriaxone 100 mg/kg of body weight twice a day [b.i.d.]). Clinical parameters were monitored, and the amount of cells with proliferating activity was assessed using in vivo incorporation of bromodeoxyuridine (BrdU) and an in vitro neurosphere culture system at 3 and 4 d postinfection. DXM significantly worsened weight loss and survival. Density of BrdU-positive cells, as an index of cells with proliferating activity, was significantly lower in DXM-treated animals compared to vehicle controls (P < 0.0001). In parallel, DXM reduced neurosphere formation as an index for stem/progenitor cell density compared to vehicle treatment (P = 0.01). Our findings provide clear evidence that DXM exerts an antiproliferative effect on the hippocampus in infant rat PM. We conclude that an impairment of regenerative hippocampal capacity should be taken into account when considering adjuvant DXM in the therapeutic regimen for PM in children.     

Accuracy and Test Characteristics of Ancillary Tests of Cerebrospinal Fluid for Predicting Acute Bacterial Meningitis in Children with Low White Blood Cell Counts in Cerebrospinal Fluid

Objectives: To determine whether ancillary tests of cerebrospinal fluid (CSF), specifically, the total protein concentration, glucose concentration, and percent neutrophils, provide information for diagnosing acute bacterial meningitis among children with low white blood cell (WBC) count in CSF. Methods: The authors retrospectively reviewed CSF from children aged 1 month to 18 years undergoing lumbar puncture at Children's Hospital in Boston from 1993 to 1999. Data were supplemented with CSF test results obtained from children with 0–30 WBCs/mm³ in CSF diagnosed with acute bacterial meningitis at the same institution from 1984 to 1992. For each test, the incremental value of ancillary tests was estimated by calculating indices of performance such as the area under receiver operator characteristic curves (AUC) and interval likelihood ratios that are relatively insensitive to disease prevalence. Results: Among children with 0–30 WBCs/mm³ in CSF who met study criteria, acute bacterial meningitis was identified in ten of 7,701 (0.1%) for the period from 1993 to 1999 and supplemented with 11 additional cases for the period from 1984 to 1992. AUC values for ancillary tests were 0.61 for total protein concentration, 0.69 for glucose concentration, and 0.90 for percent neutrophils. Interval likelihood ratios were unremarkable for mildly abnormal test results. In contrast, interval likelihood ratios for markedly abnormal test results were higher: 22 for total protein concentration >120 mg/dL, 57 for neutrophils >75%, 15 for glucose concentration <20 mg/dL, and 20 for glucose concentration >120 mg/dL. Conclusions: When markedly abnormal, results of CSF total protein concentration, glucose concentration, and percent neutrophils have value for diagnosing acute bacterial meningitis, even among children with a low WBC count in CSF.     

Adjunctive N-Acetyl-l-Cysteine in Treatment of Murine Pneumococcal Meningitis

Despite antibiotic therapy, acute and long-term complications are still frequent in pneumococcal meningitis. One important trigger of these complications is oxidative stress, and adjunctive antioxidant treatment with N-acetyl-l-cysteine was suggested to be protective in experimental pneumococcal meningitis. However, studies of effects on neurological long-term sequelae are limited. Here, we investigated the impact of adjunctive N-acetyl-l-cysteine on long-term neurological deficits in a mouse model of meningitis. C57BL/6 mice were intracisternally infected with Streptococcus pneumoniae. Eighteen hours after infection, mice were treated with a combination of ceftriaxone and placebo or ceftriaxone and N-acetyl-l-cysteine, respectively. Two weeks after infection, neurologic deficits were assessed using a clinical score, an open field test (explorative activity), a t-maze test (memory function), and auditory brain stem responses (hearing loss). Furthermore, cochlear histomorphological correlates of hearing loss were assessed. Adjunctive N-acetyl-l-cysteine reduced hearing loss after pneumococcal meningitis, but the effect was minor. There was no significant benefit of adjunctive N-acetyl-l-cysteine treatment in regard to other long-term complications of pneumococcal meningitis. Cochlear morphological correlates of meningitis-associated hearing loss were not reduced by adjunctive N-acetyl-l-cysteine. In conclusion, adjunctive therapy with N-acetyl-l-cysteine at a dosage of 300 mg/kg of body weight intraperitoneally for 4 days reduced hearing loss but not other neurologic deficits after pneumococcal meningitis in mice. These results make a clinical therapeutic benefit of N-acetyl-l-cysteine in the treatment of patients with pneumococcal meningitis questionable.     

血、脑脊液常规及MRI对脑膜炎鉴别诊断的意义

目的:探索血、脑脊液(CSF)常规及MRI对病毒性、结核性、化脓性及隐球菌性脑膜炎鉴别诊断的意义。方法:回顾性分析病毒性、结核性、化脓性及隐球菌性脑膜炎患者220例的临床资料,筛选出CSF压力、氯化物、蛋白质,血中性粒细胞百分比及有无MRI病灶这5个指标,建立判定函数;比较应用此诊断标准诊断4种脑膜炎的准确性、特异性及敏感性。结果:结核性脑膜炎的约登指数为0.423,敏感性为61.7%,特异性为80.6%,ROC曲线下面积为0.902;病毒性脑膜炎的约登指数为0.425,敏感性为67.5%,特异性为75.0%,ROC曲线下面积为0.855;化脓性脑膜炎的约登指数为0.390,敏感性为65.6%,特异性为73.4%,ROC曲线下面积为0.754;隐球菌性脑膜炎的约登指数为0.194,敏感性为62.5%,特异性为56.9%,曲线下面积为0.705。结论:结合CSF压力、氯化物及蛋白含量,血中性粒细胞百分比及有无MRI病灶建立判别函数可以提高脑膜炎的早期诊断正确率,但确诊仍需病原学检测结果。     

Concentrations of Cefpirome in Cerebrospinal Fluid of Children with Bacterial Meningitis after a Single Intravenous Dose

A single intravenous dose of cefpirome, 50 mg/kg, was administered to 15 children with bacterial meningitis 24 to 48 h after initiation of standard antibiotic and steroid therapy. Cefpirome concentrations in serum and cerebrospinal fluid were determined at selected time intervals. The mean (standard deviation) peak concentration in cerebrospinal fluid (n = 5) was 10.8 (7.8) μg/ml. Drug concentrations in cerebrospinal fluid above the MIC for Streptococcus pneumoniae at which 90% of the isolates were inhibited were found 2, 4, and 8 h after the dose of cefpirome was given. The penetration of cefpirome into cerebrospinal fluid compares favorably with that of other extended-spectrum cephalosporins and suggests that this agent would be useful in the therapy of childhood meningitis, including cases caused by drug-resistant S. pneumoniae.     

结核性脑膜炎患者脑脊液S100B与一氧化氮合酶的相关性研究

目的:探讨结核性脑膜炎患者脑脊液S100B、一氧化氮合酶(iNOS)含量的动态变化及两者的相关性。方法:43例结核性脑膜炎患者(TM组)和无神经系统疾病的患者28例(对照组)均于发病后1-6 d首次采集脑脊液,以后每隔5-7 d采集1次,共5次。采用酶联免疫吸附试验(ELISA)、化学比色法分别测定2组患者不同病程脑脊液S100Bi、NOS含量。结果:发生昏迷(昏迷组)15例,未发生昏迷(无昏迷组)28例。昏迷组和无昏迷组不同病程脑脊液S100Bi、NOS含量均较对照组显著增高(P<0.05);昏迷组脑脊液S100Bi、NOS含量较无昏迷组明显增高(P<0.05);昏迷组和无昏迷组患者脑脊液S100B与iNOS含量均呈高度相关(P=0.0319,0.0337)。结论:脑脊液S100B作为脑损害的标志物,与iNOS高度相关,其含量的高低能够反映结核性脑膜炎患者病情的严重程度。     

地塞米松对脑膜炎家兔脑脊液中可溶性细胞间黏附分子-1质量浓度变化的影响

目的:探讨地塞米松(DEX)对脑膜炎家兔脑脊液(CSF)中可溶性细胞间黏附分子-1(sICAM-1)质量浓度变化的影响,为临床应用DEX辅助治疗脑膜炎提供理论依据。方法:家兔36只,随机分为模型组、地塞米松处理组和对照组;不同时点采集其脑脊液,采用ELISA法检测CSF中sICAM-1质量浓度。结果:模型组CSF sI-CAM-1质量浓度明显高于对照组同时相,差异有统计学意义(P均0.01);脑组织含水量高于对照组,差异有统计学意义(P0.01)。地塞米松处理组CSF sICAM-1质量浓度低于模型组同时相,差异有统计学意义(P均0.05),脑组织含水量低于模型组,差异有统计学意义(P0.05)。结论:细菌性脑膜炎(BM)病程中sICAM-1分泌增多,细胞间黏附分子-1(ICAM-1)参与脑水肿形成;DEX通过抑制ICAM-1表达和(或)分泌,而减轻血脑屏障损害,减轻脑水肿形成。     

Intrathecal Treatment with the Anti-Phosphorylcholine Monoclonal Antibody TEPC-15 Decreases Neuronal Damage in Experimental Pneumococcal Meningitis

Background: Neuronal injury in pneumococcal meningitis is a consequence of microglial activation and direct toxicity by bacterial products and systemic inflammation. Methods: The treatment effect of the TEPC-15 antibody recognizing teichoic and lipoteichoic acids was investigated in murine microglial cells and in a rabbit model of pneumococcal meningitis. Results: In vitro, the TEPC-15 antibody recognizing teichoic and lipoteichoic acids increased Streptococcus pneumoniae phagocytosis by murine microglial cells. In rabbit ceftriaxone-treated S. pneumoniae meningitis, intracisternal TEPC-15 reduced the density of apoptotic neurons in the hippocampal dentate gyrus (116 ± 70 vs. 221 ± 132/mm(2); p = 0.03). Cerebrospinal fluid inflammatory parameters (protein, lactate, leukocytes, prostaglandins) were not reduced in TEPC-15-treated rabbits. Conclusion: Intracisternal treatment with the TEPC-15 antibody reduced neuronal damage probably by promoting rapid phagocytosis of bacterial products.     

一起由A群脑膜炎奈瑟菌引起的流行性脑脊髓膜炎暴发

目的探讨贵州省流脑暴发疫情的流行特征和控制措施。方法对德江县2005年的一起流脑暴发疫情调查资料和实验室结果进行了分析。结果21例病人中5-15岁年龄组占76.19%。全部病例既往无流脑疫苗接种史。病人脑脊液和密切接触者咽拭子标本中分离出7株A群脑膜炎奈瑟菌。菌株对磺胺、头孢曲松和利福平敏感。结论早期明确诊断和报告、将流脑疫苗纳入计划免疫应该是今后贵州省控制流脑疫情的关键。