Genes affecting acetylcholine (ACh) levels without influencing choline acetyltransferase activity have been identified in Caenorhabditis elegans. We have examined one such gene, unc-18. We isolated a transposon-insertion allele for unc-18 and used it to clone a genomic region containing the unc-18 locus. The unc-18 location within this region was determined by rescuing the unc-18 mutant phenotype in a germ-line transformation experiment and identifying transcripts affected by four independent unc-18 mutations. A single-sized poly(A)+ RNA was synthesized from the gene. Expression of the transcript appears to be stage specific: The transcript is found in abundance at the early larval stage but in decreased amounts at the fourth larval and the adult stages. These results show that the unc-18 gene plays a role in development as well as in the kinetics of ACh metabolism.

No abstract

Bloodstream infection (BSI) is a severe complication in immunocompromised patients. Next-generation sequencing (NGS) allows us to analyze comprehensively and quantitatively all microorganisms present in a clinical sample. Thirty-five pediatric patients (12 with BSI and 23 with suspected BSI/negative blood culture) were enrolled. Plasma/serum samples were used for sequencing and the results were compared with those from blood culture. Sequencing reads of bacteria isolated in blood culture were identified by NGS in all plasma/serum samples at disease onset. Bacteria isolated in blood culture were identical to the dominant bacteria by NGS in 8 of 12 patients. Bacterial reads per million reads of the sequence depth (BR) > 200 and relative importance values of the dominant bacteria (P1) > 0.5 were employed to determine causative pathogens. Causative pathogens were detected using these criteria in 7 of 12 patients with BSI. Additionally, causative bacteria were detected in the plasma/serum at 7 days before disease onset in two patients with catheter-related BSI. Causative pathogens, including virus, were identified in three patients with suspected BSI. Lastly, a total of 62 resistance genes were detected by NGS. In conclusion, NGS is a new method to identify causative microorganisms in BSI and may predict BSI in some patients.

Acute encephalitis/encephalopathy is a severe neurological syndrome that is occasionally associated with viral infection. Comprehensive virus detection assays are desirable because viral pathogens have not been identified in many cases. We evaluated the utility of next-generation sequencing (NGS) for detecting viruses in clinical samples of encephalitis/encephalopathy patients. We first determined the sensitivity and quantitative performance of NGS by comparing the NGS-determined number of sequences of human herpesvirus-6 (HHV-6) in clinical serum samples with the HHV-6 load measured using real-time PCR. HHV-6 was measured as it occasionally causes neurologic disorders in children. The sensitivity of NGS for detection of HHV-6 sequences was equivalent to that of real-time PCR, and the number of HHV-6 reads was significantly correlated with HHV-6 load. Next, we investigated the ability of NGS to detect viral sequences in 18 pediatric patients with acute encephalitis/encephalopathy of unknown etiology. A large number of Coxsackievirus A9 and mumps viral sequences were detected in the cerebrospinal fluid of 2 and 1 patients, respectively. In addition, Torque teno virus and Pepper mild mottle viral sequences were detected in the sera of one patient each. These data indicate that NGS is useful for detection of causative viruses in patients with pediatric encephalitis/encephalopathy.

No abstract