Investigation of a Legionella pneumophila Outbreak at a Bath Facility in Japan Using Whole-Genome Sequencing of Isolates from Clinical and Environmental Samples.

Exposure to aerosols containing Legionella from artificially made water systems has been established as a primary cause of Legionnaires' disease. In this study, we investigated an outbreak of L. pneumophila serogroup 1 sequence type 138 which occurred at a bath facility in 2022. The whole-genome sequencing of isolates revealed that the colonization of L. pneumophila at the bath facility had occurred before 2013, and the patients had been exposed to multiple genetic lineages of the strain. Our study demonstrates the importance of performing a careful comparative genetic analysis of clinical and environmental isolates from LD outbreaks in order to effectively investigate and prevent future LD outbreaks.

[Evaluation of an Analytical Method Using GC-MS/MS and a 3-Layer Solid Phase Extraction Mini-Column for Pesticide Residues in Agricultural Products].

We developed a simple rapid analysis of multi-pesticide residues in agricultural products. In this study, we attempted to simplify the purification process, and reduce the amount and type of solvent used. The test solution was prepared by clean-up, a 0.5 mL aliquot of QuEChERS extract solution of agricultural products using a 3-layer solid-phase (C18/SAX/PSA) extraction mini-column, and the test solution was subjected to GC-MS/MS analysis, modified with a large volume injection and a stomach-type glass-lined injector. This method met the acceptability criteria of recovery (70-120%) and standard deviation of repeatability (RSD<25%) in 241-331 pesticides in 8 types of agricultural products.