Novosphingobium beihaiensis sp. nov., a novel pesticide-tolerant bacterium isolated from mangrove sediments.

A novel Novosphingobium species, designated strain B2638T, was isolated from mangrove sediments which was collected from Beibu Gulf, Beihai, P. R. China. The isolate could grow in the presence of chlorpyrifos. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the isolate belonged to the genus Novosphingobium, showing 99.9% sequence similarity with N. decloroationis 502str22T and less than 98% similarity with other type strain of species of this genus. Molecular typing by BOX-PCR divided strain B2638T and N. declorationis 502str22T into two clusters and indicated that they were not identical. Genomic comparison referenced by values of the DNA-DNA hybridization (dDDH) and the average nucleotide identity (ANI) between strain B2638T and its close phylogenetic neighbors were 20.0-29.5% and 75.3-85.3%, respectively, that were lower than proposed thresholds for bacterial species delineation. The major fatty acids (> 10%) were identified as C18:1 ω7c, C17:1 iso ω9c and C16:0. The main polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, phosphatidyl glycerol, unidentified lipid and unidentified aminolipid. Results from phenotypic, chemotaxonomic and genotypic analyses proposed that strain B2638T (= MCCC 1K07406T = KCTC 72968 T) is represented a novel species in the genus Novosphingobium, for which the names Novosphingobium beihaiensis sp. nov. is proposed.

Evaluation of the Application Effect of a New Anti-reflux Water Injection Tube Device in the Prevention of the Contamination of Endoscopy Water Injection Bottles.

BACKGROUND: Water delivery tube reflux during gastrointestinal endoscopy examination is widespread and it is the leading cause of water injection bottle pollution. AIM: To evaluate the application effect of a new anti-reflux water injection tube device in preventing the contamination of endoscopy water injection bottles. METHODS: A total of 520 cases received gastrointestinal endoscopy examination were included. Patients were randomly divided into the experimental and control group. The experimental group used the anti-reflux injection tube device to assist with water injection, and the control group used the ordinary delivery tube. After every five cases of gastrointestinal endoscopy, water from the injection bottles was collected. Visual inspection, crystalline violet staining, microbial culture, and microbial species analysis were performed to analyze the contamination state of the water samples. RESULTS: The contamination rate in the experimental group was 5.66%, significantly lower than 76.47% in the control group. Crystalline violet staining confirmed that microorganisms existed in contaminated water samples. Microbiological culture results showed that the experimental group's undetectable rate of bacteria and fungi was 100%, significantly higher than that of the control group (19.61% for bacteria and 25.49% for fungi). The mean values of the total bacterial and fungal colonies of the control samples were 9.80 × 106 cfu/ml and 9.18 × 106 cfu/ml, respectively. The microbial species in the contaminated samples of the control group were Pseudomonas aeruginosa, Escherichia coli, and Proteus mirabilis. CONCLUSION: The anti-reflux water injection tube device can effectively prevent the contamination of the endoscopy water injection bottles caused by the reflux of the ordinary water supply tube.