Treating Anthrax-Induced Meningitis in Rabbits.

Treatment of anthrax is challenging, especially during the advanced stages of the disease. Recently, the Centers for Disease Control and Prevention (CDC) updated its recommendations for postexposure prophylaxis and treatment of exposed populations (before and after symptom onset). These recommendations distinguished, for the first time, between systemic disease with and without meningitis, a common and serious complication of anthrax. The CDC considers all systemic cases meningeal unless positively proven otherwise. The treatment of patients suffering from systemic anthrax with suspected or confirmed meningitis includes the combination of three antibiotics, i.e., a fluoroquinolone (levofloxacin or ciprofloxacin), a ß-lactam (meropenem or imipenem), and a protein synthesis inhibitor (linezolid or clindamycin). In addition, treatment with an antitoxin (anti-protective antigen antibodies) and dexamethasone should be applied. Since the efficacy of most of these treatments has not been demonstrated, especially in animal meningitis models, we developed an anthrax meningitis model in rabbits and tested several of these recommendations. We demonstrated that, in this model, ciprofloxacin, linezolid, and meropenem were ineffective as single treatments, while clindamycin was highly effective. Furthermore, combined treatments of ciprofloxacin and linezolid or ciprofloxacin and dexamethasone failed in treating rabbits with meningitis. We demonstrated that dexamethasone actually hindered blood-brain barrier penetration by antibiotics, reducing the effectiveness of antibiotic treatment of anthrax meningitis in this rabbit model.

[Clinical analysis and follow-up of neonatal purulent meningitis caused by group B streptococcus].

OBJECTIVE: To study the clinical characteristics, antibiotics sensitivity and outcome of group B streptococcus (GBS) meningitis in neonates in order to provide the guide for early diagnosis and appropriate treatment. METHOD: A retrospective review was performed and a total of 13 cases of neonatal purulent meningitis caused by GBS were identified in the Neonatal Intensive Care Unit of Yuying Children's Hospital of Wenzhou Medical University from January 1, 2005 to May 31, 2013. The clinical characteristics, antibiotics sensitivity test results and outcome were analyzed. RESULT: Fever, poor feeding, seizure and lethargy were common clinical signs of neonatal purulent meningitis caused by GBS. Three cases of early onset GBS meningitis received prepartum antibiotics. All 13 cases had abnormal C-reactive protein (CRP) level, and 11 cases had increased CRP within hours after admission. Of the 13 patients, 7 were cured, 4 discharged with improvement, 2 patients died during hospitalization after being given up because of serious complication. The average length of stay for recovered patients was (47 ± 21)d. Acute complications mainly included hyponatremia (5 cases), intracranial hemorrhage (3 cases) , ventriculomegaly (3 cases) , subdural collection (2 cases) , hydrocephalus (2 cases), septic shock (2 cases), cerebral hernia (1 case), encephalomalacia (1 case). One preterm patient with early onset GBS meningitis died 1 month after hospital discharge. Among 7 survivors with 10-24 months follow-up, 3 were early onset GBS meningitis, 2 with normal results of neurologic examination, 1 with delayed motor development, 4 were late onset GBS meningitis, 1 with normal results of neurologic examination, 3 were neurologically impaired with manifestations including delayed motor development (2 cases) and seizures (1 case). All the GBS strains were sensitive to penicillin and linezolid (13/13, 10/10), the susceptibility to levofloxacin, ampicillin and vancomycin were 11/12, 9/10, 8/13 respectively. CONCLUSION: The clinical manifestations of neonatal purulent meningitis caused by GBS are usually non-specific. It is associated with long hospitalization, neurological impairments and sequelae. Monitoring of serum CRP level is valuable for early diagnosis. Antepartum prophylaxis, early diagnosis and therapy are vital. Large dose penicillin is the priority choice to treat the neonatal purulent meningitis caused by GBS, linezolid should be used in intractable cases.

Distributed, limbic gray matter atrophy in patients after bacterial meningitis.

BACKGROUND AND PURPOSE: The structural basis of cognitive sequelae after bacterial meningitis in humans is still poorly understood. In animal models and human autopsy cases, neuronal apoptosis of the hippocampal formation in particular seems to play an important role. Here, we aimed to analyze if BM entails MR imaging structural consequences in humans in vivo. MATERIALS AND METHODS: We applied voxel-based morphometry in a cohort of BM survivors with normal conventional MR imaging after resolution of the acute inflammation to assess morphologic differences. RESULTS: We found clear gray matter volume loss in the limbic system including the hippocampal formation, thalamus, and cingulate gyri bilaterally as well as in the temporal lobe. These results were corroborated by an alternative atlas-based method. CONCLUSIONS: Even in patients with normal routine MR imaging results, clear-cut gray matter atrophy with a mesial temporal/limbic pattern was evident. The anatomic distribution is compatible with the neuropsychological deficit commonly observed in patients after BM. The similarity of the observed atrophy may point to causal link between BM and mesial temporal epilepsy.

Neurotrasmisores en niños con meningitis bacteriana / Neurotransmitters in children with bacterial meningitis

La meningitis bacteriana continúa siendo una enfermedad potencialmente fatal, especialmente en países en vías de desarrollo. Los aminoácidos excitatorios están fuertemente implicados en la patogénesis del daño neuronal en meningitis bacteriana. El objetivo fue medir niveles de glutamato, GABA, glicina y taurina en liquido cefalorraquídeo y correlacionarlos con el grado de severidad, complicaciones y secuelas. Estudio prospectivo en 31 pacientes con meningitis bacteriana y 10 pacientes con líquido cefalorraquídeo normal (control), con edades de 1 mes - 13 años de edad. El análisis de aminoácidos se realizó al ingreso y al tercer día mediante cromatografía líquida de alta presión. De los 31 pacientes que ingresaron al estudio 64,5 % fueron de género femenino, 13 lactantes, 8 preescolares y 10 escolares. El promedio de aminoácidos en los niños con meningitis fue más alto que en el grupo control (P<0,01). El glutamato disminuyó significativamente en pacientes con hidrocefalia. El GABA está disminuido en pacientes con parálisis cerebral y la taurina está disminuida en higroma y aumentada en lesión de pares craneales, trastornos de la conducta e hipoacusia. Los cambios en los niveles de aminoácidos en líquido cefalorraquídeo refleja el estado patológico y severidad del daño cerebral. Este estudio provee información del eventual papel de la inmunomodulación y posible uso de antagonistas de aminoácidos excitatorios, con efecto neuroprotector, en el tratamiento de meninigitis bacteriana e indica que esta clase de molécula neurotóxica puede represetar un importante blanco en la terapia adyuvante para meningitis bacteriana.

Bacterial meningitis rmains a potentially fatal disease, especially in developing countries. Exitatory amino acids are strongly implicated in the pathogenesis of neuronal damage in bacterial meningitis. To measure levels of glutamate, GABA, glycine and taurine in cerebroespinal fluid and correlate with the degree of severity, complications and sequelae. Prospective study in 31 patients with bacterial meningitis and 10 patients with normal cerebrospinal fluid (control), aged 1 month - 13 years old. Amino acid analysis was performed on admission and on the third day using high pressure liquid chromatography. Of the 31 patients entering the study 64.5 % were females, 13 infants, 8 preschoolers and 10 elementary school students. The average number of amino acids in children with meningitis was higher than in the control group (P<0.01). Glutamate levels significantly decreased in patients with hydrocephalus. GABA levels decreased in patients with cerebral pasly, and taurine diminished in hygroma, and increased in cranial nerve injury, eating disorders and hearing loss. Changes in amino acid levels in cerebrospinal fluid reflect pathological state and severity of brain damage. This study provides information on the possible role of immunomudulation and possible use of excitatory amino acid antogonists with neuroprotective effects in the treatment of bacterial meningitis, indicating that this class of neurotoxic molecules may represent important target in adjuvant therapy for bacterial meningitis.