Unveiling the early life core microbiome of the sea cucumber Apostichopus japonicus and the unexpected abundance of the growth-promoting Sulfitobacter.

BACKGROUND: Microbiome in early life has long-term effects on the host's immunological and physiological development and its disturbance is known to trigger various diseases in host Deuterostome animals. The sea cucumber Apostichopus japonicus is one of the most valuable marine Deuterostome invertebrates in Asia and a model animal in regeneration studies. To understand factors that impact on host development and holobiont maintenance, host-microbiome association has been actively studied in the last decade. However, we currently lack knowledge of early life core microbiome during its ontogenesis and how it benefits the host's growth. RESULTS: We analyzed the microbial community in 28 sea cucumber samples from a laboratory breeding system, designed to replicate aquaculture environments, across six developmental stages (fertilized eggs to the juvenile stage) over a three years-period to examine the microbiomes' dynamics and stability. Microbiome shifts occurred during sea cucumber larval ontogenesis in every case. Application of the most sophisticated core microbiome extraction methodology, a hybrid approach with abundance-occupancy core microbiome analyses (top 75% of total reads and > 70% occupation) and core index calculation, first revealed early life core microbiome consisted of Alteromonadaceae and Rhodobacteraceae, as well as a stage core microbiome consisting of pioneer core microbe Pseudoalteromonadaceae in A. japonicus, suggesting a stepwise establishment of microbiome related to ontogenesis and feeding behavior in A. japonicus. More interestingly, four ASVs affiliated to Alteromonadaceae and Rhodobacteraceae were extracted as early life core microbiome. One of the ASV (ASV0007) was affiliated to the Sulfitobactor strain BL28 (Rhodobacteraceae), isolated from blastula larvae in the 2019 raring batch. Unexpectedly, a bioassay revealed the BL28 strain retains a host growth-promoting ability. Further meta-pangenomics approach revealed the BL28 genome reads were abundant in the metagenomic sequence pool, in particular, in that of post-gut development in early life stages of A. japonicus. CONCLUSION: Repeated rearing efforts of A. japonicus using laboratory aquaculture replicating aquaculture environments and hybrid core microbiome extraction approach first revealed particular ASVs affiliated to Alteromonadaceae and Rhodobacteraceae as the A. japonicus early life core microbiome. Further bioassay revealed the growth promoting ability to the host sea cucumber in one of the core microbes, the Sulfitobactor strain BL28 identified as ASV0007. Genome reads of the BL28 were abundant in post-gut development of A. japonicus, which makes us consider effective probiotic uses of those core microbiome for sea cucumber resource production and conservation. The study also emphasizes the importance of the core microbiome in influencing early life stages in marine invertebrates. Understanding these dynamics could offer pathways to improve growth, immunity, and disease resistance in marine invertebrates.

Genome taxonomy of the genus Neptuniibacter and proposal of Neptuniibacter victor sp. nov. isolated from sea cucumber larvae.

A Gram-staining-negative, oxidase-positive, strictly aerobic rod-shaped bacterium, designated strain PT1T, was isolated from the laboratory-reared larvae of the sea cucumber Apostichopus japonicus. A phylogenetic analysis based on the 16S rRNA gene nucleotide sequences revealed that PT1T was closely related to Neptuniibacter marinus ATR 1.1T (= CECT 8938T = DSM 100783T) and Neptuniibacter caesariensis MED92T (= CECT 7075T = CCUG 52065T) showing 98.2% and 98.1% sequence similarity, respectively. However, the average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) values among these three strains were 72.0%-74.8% and 18.3%-19.5% among related Neptuniibacter species, which were below 95% and 70%, respectively, confirming the novel status of PT1T. The average amino acid identity (AAI) values of PT1T showing 74-77% among those strains indicated PT1T is a new species in the genus Neptuniibacter. Based on the genome-based taxonomic approach, Neptuniibacter victor sp. nov. is proposed for PT1T. The type strain is PT1T (JCM 35563T = LMG 32868T).

Accuracy of the Data of Biochemical Parameters in Blood Collected Above the Infusion Insertion Site.

The authors aimed to investigate the possibility of collecting blood samples from above patient intravenous infusion sites by temporarily stopping the infusions while collecting the blood. A hypotonic infusion solution was administered to 5 male patients through the cephalic veins in the forearms of their left upper limbs. The biochemical data of blood collected from the median cubital veins of both patients' arms were compared. The results showed that infusions could change some biochemical test parameters, such as potassium and glucose, to higher levels, even if the infusion was interrupted temporarily during the blood collection from above the insertion site. Blood counts remained unchanged under the same conditions. If the evaluation is performed solely to assess blood counts, using a blood collection site above the insertion site by temporarily interrupting the infusion is feasible.

Evaluation of Blood Collection From the Proximal Side of a Fluid Infusion Site.

BACKGROUND: We aimed to determine if blood data are unaffected by transfusion method when the blood is sampled from the proximal side of the infusion site under temporary suspension of transfusion. METHODS: In five 30-week-old Japanese white male rabbits, fluid infusion routes were secured via left auricular veins with a disposable plastic indwelling cannula (24-G needle). Solita T3 (22 mL/h) was administered to each animal using a syringe pump. Ten minutes after starting infusion, 2 mL blood was sampled from a distance of 2 cm on the central side of the infusion site with ongoing fluid infusion, from the opposite side (the right auricular vein), and from the central side of the infusion site with suspended fluid infusion. We cross-verified and compared results of 41 biochemical and blood cell examination items for samples collected from the central side with ongoing fluid infusion, from the central side with suspended fluid infusion, and from the opposite sides by comparison with Tukey's test. RESULTS: A significant difference was noted in tested items between blood samples collected from the proximal side with ongoing fluid infusion and those collected from the proximal side and from the contralateral side with suspended fluid infusion. Conversely, for all test items, no significant difference was noted in the test item data between blood samples collected from the proximal side with suspended fluid infusion and those collected from the contralateral side. CONCLUSIONS: We successfully verified and demonstrated that blood samples collected from the proximal side of the infusion site remain unaffected by fluid infusion when drawn under the conditions of suspended fluid infusion.

Experimental Research of Blood Collected From the Peripheral Side of the Fluid Infusion Site That Is Not Affected by Fluid Infusion.

BACKGROUND: The objective of this study was to determine a safe blood sample collection site for clinical investigations, in patients with an in situ intravenous line, which would minimize distress to the patient and provide accurate blood data. METHODS: An intravenous line was established in the left upper limb for administration of Solita T3G (84 mL/h). After 5 min of infusion, two nurses simultaneously collected venous blood samples (vacuum blood collection method) from a site on dorsum of the left hand located 15 cm distal to the site of fluid infusion (the peripheral side), and the cubital fossa of the contralateral upper limb (the opposite side). The results obtained from the blood samples of the contralateral side served as the standard reference. Testing of 41 blood-cell tests and biochemical parameters were outsourced to a specialized company. Between-group differences in test results for the two locations were assessed using the paired t-test, with a significance level of < 5%. RESULTS: No significant differences in mean values (± standard deviation) of blood parameters were observed between the distal site and the contralateral side. CONCLUSION: Blood samples collected from a venous site located 15 cm distal to the fluid-infusion site did not show any effect of fluid infusion on the results.

Dietary Intake in Body Mass Index Differences in Community-Based Japanese Patients with Schizophrenia.

BACKGROUND: Patients with schizophrenia reportedly have a high prevalence of obesity. One of the reasons is a poor choice of diet. The goal of this study was to clarify characteristics of the dietary intake across the strata of the body mass index (BMI) and to compare the general population and patients with schizophrenia in Japan. METHODS: This is a cross-sectional study of 51 patients with schizophrenia residing in rural areas in 2011. Anthropometric indices (of height, weight, body mass index) were measured at the commencement of the survey. Intakes of energy, protein, fat, carbohydrate, calcium, phosphorus, vitamins, total fiber, and salt were noted through a 3-day dietary recording. The nutrient intake was estimated using Excel add-in software (Excel Eiyou-kun Ver. 6.0, Kenpakusha Co., Ltd.). Patients were divided into two groups: those with a BMI ≥25 kg/m(2) and with a BMI <25 kg/m(2), and the differences in their nutrition intake were analyzed. To compare these patients with the general population, the results of the National Health and Nutrition Survey, 2010 (NHNS) were used (the NHNS group). For statistical analysis, an unpaired t-test was performed with P < 0.05. RESULTS: Patients with a BMI ≥25 kg/m(2) had the higher intakes than those with a BMI <25 kg/m(2) of energy, fat and phosphorus and salt. Patients with schizophrenia showed higher intakes of energy, carbohydrate, fat, calcium, phosphorus and salt than the NHNS group. CONCLUSION: The characteristics of the dietary intake in patients with schizophrenia were suggested the food constitution that is likely to increase the body weight.