Agents In Cerebrospinal Fluid Research Articles

Viral aetiology of acute central nervous system infections in children, Iran.

Introduction. Viral infections are increasingly an important cause of central nervous system (CNS) complications.Hypothesis/Gap Statement. There is no comprehensive insight about CNS infections due to viral agents among Iranian children.Aim. This study aimed to investigate the viral aetiology, clinical and epidemiological profile of children with acute infections of the CNS.Methodology. A prospective study was conducted on children at the referral hospital in Isfahan, Iran, from June 2019 to June 2020. A multiplex PCR assay was used to detect the viral causative agent in cerebrospinal fluid and throat/rectal swab samples.Results. Among 103 patients with eligible criteria, a confirmed or probable viral aetiology was detected in 41 (39.8 %) patients, including enteroviruses - 56.1 %, herpes simplex virus 1/2 (HSV-1/2) - 31.7 %, Epstein-Barr virus - 17.1 %, varicella-zoster virus (VZV) - 9.7 %, influenza A virus (H1N1) -4.9 % and mumps - 2.4 %. There was a higher proportion of PCR-positive samples in infants than in other age groups. Encephalitis and meningoencephalitis were diagnosed in 68.3 % (28/41) and 22 % (9/41) PCR-positive cases, respectively.Conclusion. The findings of this research provide insights into the clinical and viral aetiological patterns of acute CNS infections in Iran, and the importance of molecular methods to identify CNS viruses. HSV and VZV were identified as important causes of encephalitis in young children.

Molecular detection of Sarcocystis neurona in cerebrospinal fluid from 210 horses with suspected neurologic disease

An ante-mortem diagnosis of equine protozoal myeloencephalitis (EPM) is presently based on clinical presentation, immunodiagnostics performed on serum and cerebrospinal fluid (CSF), and ruling out other neurological disorders. Molecular techniques introduce a novel and promising approach for the detection of protozoal agents in CSF. Hypothesizing that real-time PCR (rtPCR) can be a useful complement to EPM diagnostics, 210 CSF samples from horses suspected of neurological disease with EPM included as a differential diagnosis were tested using rtPCR to detect Sarcocystis neurona DNA and immunodiagnostics targeting antibodies against the same pathogen, performed on serum and CSF samples. Molecular and immunological results were compared with respect to origin of the horse, time of the year, signalment, clinical signs and treatment history. Twenty-five horses tested positive in CSF for S. neurona by rtPCR only, while 30 horses had intrathecally-derived antibodies to S. neurona only (serum to CSF ratio ≤ 64 by indirect fluorescent antibody test - IFAT), and 13 horses tested rtPCR-positive in CSF with evidence of intrathecally-derived antibodies to S. neurona. Previous treatment for EPM was the only variable presenting statistical difference between the two testing modalities, highlighting that animals with history of anti-protozoal treatment were more likely to test positive solely in IFAT, while horses without treatment were more likely to test positive by rtPCR only. The results support the use of molecular diagnosis for EPM caused by S. neurona as a complement to immunodiagnostics. The use of rtPCR in CSF for the detection of S. neurona may improve the diagnostic work-up of neurologic disease suspected horses, especially in animals without previous anti-protozoal treatment.

Search for viral agents in cerebrospinal fluid in patients with multiple sclerosis using real-time PCR and metagenomics.

Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease of the central nervous system of unclear etiology, but there is some evidence that viral infections could be responsible for triggering autoimmune mechanisms against myelin. We searched for viral RNA and DNA in cerebrospinal fluid (CSF) of 34 MS patients and 13 controls using RT-PCR/PCR against common neurotropic viruses. In addition, shotgun DNA- and RNA-based metagenomics were done in 13 MS patients and 4 controls. Specific quantitative real-time RT-PCR/PCR testing revealed the presence of viral nucleic acid in seven (20.59%) MS patients and in one (7.69%) control patient. In MS patients the most frequently detected was human herpesvirus type 6 (HHV-6; 3 cases; 8.82%); followed by Epstein-Barr virus (EBV; 2 cases; 5.88%), varicella zoster virus (VZV; 1 case; 2.94%) and Enterovirus (EV; 1 case; 2.94%). The single identified virus among controls was EBV (7.69%). DNA and RNA metagenomic assays did not identify any known eukaryotic viruses even though three of the analyzed samples were low-level positive by specific quantitative real-time PCR. In conclusion, we detected the presence of Herpesviridae and occasionally Enteroviridae in CSF from patients with MS but their prevalence was not significantly higher than among controls. Metagenomic analysis seems to be less sensitive than real-time RT-PCR/PCR and it did not detect any potential viral pathogens.

In vitro activity of voriconazole and amphotericin B against Candida albicans, Candida krusei, and Cryptococcus neoformans in human cerebrospinal fluid

PurposeFungal central nervous system (CNS) infections show a high mortality rate and only a few antifungal agents are available to treat these infections. We hypothesize that the different biochemical properties of human cerebrospinal fluid (CSF) compared to the standard growth medium lead to the altered activity of antifungal agents in CSF. We investigated the in vitro activity of two of these agents, i.e., amphotericin B (AmB) and voriconazole (VOR), against three different fungi in CSF in comparison to sabouraud-dextrose broth (SDB).MethodsCSF samples from patients who did not receive any antibiotics were collected. Time-kill curves were performed in CSF and SDB using static antibiotic concentrations of AmB and VOR against ATCC strains of Candida albicans, Candida krusei, and Cryptococcus neoformans.ResultsIn our experiments, both AmB and VOR showed superior activity in SDB compared to CSF. Nevertheless, AmB achieved fungicidal activity in CSF after 24 h against all test strains. Voriconazole only achieved fungistatic activity against C. albicans and C. neoformans in CSF.ConclusionsIn summary, our data demonstrate that growth of fungal pathogens but even more importantly activity of antifungal agents against Candida and Cryptococcus species can differ significantly in CSF compared to the standard growth medium. Both findings should be taken into consideration when applying PK/PD simulations to fungal infections of the CNS.

Stroke-like migraine attacks after radiation therapy: A misnomer?

To understand the frequency of electrographic and clinical seizures in patients with stroke-like migraine attacks after radiation therapy (SMART), and determine whether SMART warrants comprehensive electroencephalographic (EEG) monitoring and aggressive seizure management. We searched our magnetic resonance brain imaging report database for all patients between January 2013 and December 2015 for suspected SMART syndrome. Clinical inclusion criteria were further applied as follows: inpatient adults (>18 years of age) with history of cranial radiation presenting with acute neurologic deficits as primary admission reason who lacked evidence of recurrent or new brain malignancy, stroke, or infectious agents in cerebrospinal fluid. Six patients were identified. All 6 patients underwent prolonged video EEG monitoring as part of our standard protocol. All patients but 1 were found to have multiple or prolonged electrographic seizures consistent with status epilepticus during video EEG monitoring. Their neurological deficit and/or mental status change improved in parallel with resolution of the seizure activity. SMART is likely a misnomer that underestimates the significance of seizures and status epilepticus in the pathophysiology and clinical presentation of the syndrome. Systematic continuous EEG monitoring and appropriate seizure management is warranted to reduce symptom duration and optimize clinical outcome.

Determination of vancomycin trough level in serum and cerebrospinal fluid of patients with acute community-acquired meningitis: A prospective study

Penetration and concentration of vancomycin is still an elusive and complex issue particularly in Cerebrospinal Fluid (CSF). The aim of this study was to clarify the penetration of this antimicrobial agent in CSF during meningeal inflammation. In a prospective study, adult patients, with clinical and CSF analysis compatible with acute meningitis, who received vancomycin (15 mg/kg loading and 30 mg/kg daily maintenance dose) with ceftriaxone (4 gr/daily) were enrolled. CSF analysis including vancomycin trough levels before the fourth maintenance dose and during the 8-10th days of treatment, and simultaneous serum levels were performed by High-Pressure Liquid Chromatography (HPLC). Twenty-seven patients (18 men, 9 women; mean age of 39.4 ± 14.7) were enrolled. The first serum trough level of vancomycin was 13.82 ± 1.28 mg/l. The mean of corresponding trough level in CSF was 11.2 ± 1.41 mg/l. The serum and CSF trough levels revealed positive linear correlation (r: 0.60) and was significant at the 0.01 level (P: 0.004). The penetration CSF/serum ratio was 0.811 ± 0.082 (coefficient of variation: 10.1%). The second trough levels of serum and CSF in (14 patients) vancomycin were 13.32 ± 1.02 and 10.64 ± 1.21, respectively. The serum and CSF trough levels revealed positive linear correlation (r: 0.71). The serum and CSF concentrations revealed no variation compared to the first trough levels. Vancomycin has appropriate concentration in CSF during the treatment of meningitis and do not decrease along with the alleviation of meningeal inflammation in spite of concerns in this regard.

Enteroviruses in Patients with Acute Encephalitis, Uttar Pradesh, India

An outbreak of viral encephalitis occurred in northern India in 2006. Attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcription–PCR showed positivity to enterovirus (EV) in 66 (21.6%) of 306 patients. Sequencing and phylogenetic analyses of PCR products from 59 (89.3%) of 66 specimens showed similarity with EV-89 and EV-76 sequences.

Cerebral aspergillosis: tissue penetration is the key

Cerebral aspergillosis is increasingly recognized in severely immunocompromised patients and, until recently, this type of fungal infection was associated with a mortality approaching 100%. The central nervous system is a protected environment and penetration of drugs across the blood-brain barrier is mainly limited by their molecular size and physicochemical properties, as well as drug interaction with transporter systems (e.g., P-glycoprotein) at the blood-brain barrier. Most antifungal agents are large molecules (>700 Da), which makes sufficient penetration into the central nervous system unlikely. In fact, the available data indicate low levels of most antifungal agents in cerebrospinal fluid and brain tissue, except for fluconazole and voriconazole. Concentrations of voriconazole exceeding inhibitory concentrations for Aspergillus species were found repeatedly in cerebrospinal fluid and brain tissue, including brain abscess material. A recent retrospective study confirmed that voriconazole treatment resulted in improved response and survival rates in patients with cerebral aspergillosis. Data from animal models, which explored escalated doses or combinations of antifungal agents in experimental neuroaspergillosis, suggest that selected combination or dose-escalated therapies might further improve the still unsatisfactory prognosis in this particular type of Aspergillus infection.

Anesthesia in the HIV positive or AIDS patient

To analyze the current anaesthetic management of HIV/AIDS patients. References were obtained from computerized bibliographic research (Medline), recent review articles, the library of the service, personal files. Original articles, reviews, cases reports, letters to the editor in French and English were analyzed and selected. Current data on HIV infection, perioperative clinical and biological symptoms, arguments for choice of the type of anaesthesia, risks of transmitting HIV to health care workers and protective measures were extracted. Twenty per cent of HIV-positive patients require surgery during their illness. Anaesthesia and surgery decrease cell mediated immunity and modify the activity of immune mediators. These changes are more pronounced under general anaesthesia compared to regional anaesthesia. They are transient and not clinically significant. Poor information is available concerning the perioperative management of HIV-positive patients and the effects of anesthesia on their immune status. Preoperative evaluation focuses on the following three important data: patient's status, surgery, and anaesthesia. In patients in good clinical conditions who comply with treatment, the anesthetist assesses the effects of the antiretroviral treatment and the risk of interactions between anaesthetic and antiretroviral agents. Etomidate, atracurium, cisatracurium, remifentanil and desflurane are not dependent on hepatic metabolism by the cytochrome P450 system. In patients in bad clinical conditions or in patients who do not comply with treatment, attention focuses on cardiovascular, pulmonary, neurologic and nutritional status. The specific antiretroviral treatment is not discontinued in the perioperative period, as far as compatible with the type of surgery and associated dysfunction of the digestive tract. Regional anaesthesia offers the benefits of not interfering with the immune system and antiretroviral agents. However, the viral infection can be enhanced by regional anaesthesia due to the cofactors' effect of local anaesthetic agents in cerebrospinal fluid. Homologous blood transfusion is not recommended as it increases postoperative infection and viral activation. Erythropoietin can be of benefit in selected cases. In the future, supportive immunotherapy will probably be the main tool for perioperative management of HIV and AIDS patients.

Polymerase chain reaction with the 30-kb circular plasmid of Borrelia burgdorferi B31 as a target for detection of the Lyme borreliosis agents in cerebrospinal fluid

The polymerase chain reaction (PCR) was developed for use in the detection of Borrelia burgdorferi sensu lato, the Lyme disease agent. A 333-bp fragment of the 30-kbp circular plasmid from Borrelia burgdorferi B31 was amplified and PCR products were analysed by DNA-DNA hybridization. Sensitivity was enhanced by addition of a carrier to the samples before treatment and enabled detection of as few as 1 to 10 bacteria. Specific products were obtained only with the lyme disease agents, but not with other spirochetes or unrelated bacteria. B. burgdorferi sensu lato was detected in cerebrospinal fluid (CSF) from 11 out of 45 patients with confirmed Lyme neuroborreliosis. In a prospective study, 20 out of 315 CSF samples from potential patients were PCR-positive. Forty uninfected patients were PCR-negative.

Vergleichsuntersuchungen mit 2 neuen und 8 bekannten Nährmedien zur Anzüchtung anspruchsvoller und anspruchsloser Erreger aus Liquor und anderen Körperflüssigkeiten

Rapid physical, biochemical and immunological methods may be useful in the detection of microbial agents in cerebrospinal fluid and in other body fluids. However, these methods are no substitution for the cultivation of the microbial agents. Microorganisms which are most frequently responsible for meningitis are fastidious in their growth requirements. Their detection with the help of conventional blood culture media which are not supplemented with blood or its components, leads to a high quota of false-negative results. Taking this problem into consideration, the authors developed the following two new media: “MOPS Electrolyte Broth A” for culturing obligate aerobic and facultative anaerobic microorganisms, and “MOPS Electrolyte Broth AN” for culturing facultative anaerobic and obligate anaerobic bacteria.Performance tests have been carried out with the two above mentioned media and eight commercially manufactured blood culture media in original bottles. Twenty representative test strains including the most important and fastidious microbial agents of meningitis have been considered in this study. The inoculum size was about 102 CFU per culture bottle. The two new media, which were not supplemented with blood or body fluids, proved to be more effective than the conventional blood culture media supplemented with 10% fresh human blood for culturing the considered spectrum of microorganisms.

Fibrinolytic activity in CSF of patients with SAH in the acute phase measured by a rapid method (correlation with t-AMCA concentration in CSF.

To decide the minimum dose of antifibrinolytic agent for the conservative treatment of subarachnoid hemorrhage (SAH) in the acute phase, we developed a method to measure reduction in fibrinolytic activity of the cerebrospinal fluid (CSF) within a short period of time. It was reproducible and the result was expressed by the t-AMCA score. CSF was collected every 30 minutes or six hours in nine cases of SAH who were treated with an antifibrinolytic agent (t-AMCA) at a daily dose of 4-6 grams and the t-AMCA score obtained was compared with the dosage, t-AMCA concentration in CSF and daily excretion volume of CSF through drainage. The results showed that the concentration of antifibrinolytic agent in CSF was negatively correlated with the daily excretion volume of CSF, and correlated with the dosage when the excretion volume was under 150 ml/day. The t-AMCA score usually changed in a constant pattern which was not related to the concentration of antifibrinolytic agent in CSF. In cases in which treatment was initiated within 48 hours after the hemorrhage, rapid reduction of the fibrinolytic activity in CSF was obtainted within 24 hours after administration, while in one case in which treatment was performed on the 6th day after hemorrhage, a favorable reduction in the fibrinolytic activity could not be obtained until the third day after administration. In a case in which repeated assays were performed in a short period, rebound fibrinolysis was observed two hours after administration and three days after withdrawal.