Next-generation sequencing combined with serological tests based pathogen analysis for a neurocysticercosis patient with a 20-year history:a case report.

BACKGROUND: Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system (CNS) caused by the larval stage of Taenia solium. Accurate and early diagnosis of NCC remains challenging due to its heterogeneous clinical manifestations, neuroimaging deficits, variable sensitivity, and specificity of serological tests. Next-generation sequencing (NGS)-based pathogen analysis in patient's cerebrospinal fluid (CSF) with NCC infection has recently been reported indicating its diagnostic efficacy. In this case study, we report the diagnosis of a NCC patient with a symptomatic history of over 20 years using NGS analysis and further confirmation of the pathology by immunological tests. CASE PRESENTATION: This study reports the clinical imaging and immunological features of a patient with a recurrent headache for more than 20 years, which worsened gradually with the symptom of fever for more than 7 years and paroxysmal amaurosis for more than 1 year. By utilizing NGS technique, the pathogen was detected in patient's CSF, and the presence of Taenia solium-DNA was confirmed by a positive immunological reaction to cysticercus IgG antibody in CSF and serum samples. The symptoms of the patient were alleviated, and the CSF condition was improved substantially after the anti-helminthic treatment. CONCLUSIONS: This study suggests that combining CSF NGS with cysticercus IgG testing may be a highly promising approach for diagnosing the challenging cases of NCC. Further studies are needed to evaluate the parasitic DNA load in patients' CSF for the diagnosis of disease severity, stage, and monitoring of therapeutic responses.

[Comparison of the methods for extracting and purifying microbial total DNA from an aeolian sandy soil].

In order to select and establish an appropriate method for extracting and purifying the microbial total DNA from an aeolian sandy soil, six extraction methods (five direct methods and one indirect method) and two purification methods were examined, with the quantity and quality of extracted and purified total DNA compared. All the six extraction methods could extract the total DNA with a length of approximately 23 kb, among which, the improved SDS high salt extraction method (using 40% PEG8000 and 4 mol x L(-1) NaCl to precipitate DNA) was the best. This method could have a yield slightly less than that obtained by using kits, and the extracted DNA had the highest purity after purification, being available in 16S rDNA PCR amplification. Among the purification methods, the effect of agarose gel electrophoresis plus minicolumn was satisfactory, with most of the purified total DNA being able to be PCR-amplified and meet the requirements of the purity of DNA in the follow-up molecular operations.