Community Structure and Predicted Functions of Actively Growing Bacteria Responsive to Released Coral Mucus in Surrounding Seawater.

A direct relationship exists between diverse corals and fish farming in Keten Bay, Amami-Oshima, Japan. The release of coral mucus has a significant impact on the microbial activity of surrounding seawater. To obtain a more detailed understanding of biogeochemical cycles in this environment, the effects of coral mucus on the community structure and function of bacteria in surrounding seawater need to be elucidated. We herein used a bromodeoxyuridine approach to investigate the structures and functions of bacterial communities growing close to mucus derived from two different Acropora corals, AC1 and AC2. The alpha diversities of actively growing bacteria (AGB) were lower in mucus-containing seawater than in control seawater and their community structures significantly differed, suggesting that the growth of specific bacteria was modulated by coral mucus. Rhodobacteraceae and Cryomorphaceae species were the most dominant AGB in response to the mucus of Acropora AC1 and AC2, respectively. In contrast, the growth of Actinomarinaceae, Alteromonadaceae, Flavobacteriaceae, and SAR86 clade bacteria was inhibited by coral mucus. The results of a Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) ana-lysis suggested that the predicted functions of AGB in mucus-containing seawater differed from those in seawater. These functions were related to the biosynthesis and degradation of the constituents of coral mucus, such as polysaccharides, sugar acids, and aromatic compounds. The present study demonstrated that complex bacterial community structures and functions may be shaped by coral mucus, suggesting that corals foster diverse bacterial communities that enhance the ecological resilience of this fish farming area.

Galactose-deficient IgA1 Is Involved in IgA Deposition in Renal Grafts Biopsied One Hour after Kidney Transplantation.

Objective Asymptomatic renal immunoglobulin A (IgA) deposition occurs in healthy subjects, but its etiologic role in disease is unclear. Galactose-deficient IgA1 (Gd-IgA1) is involved in the pathogenesis of IgA nephropathy. We investigated Gd-IgA1 deposition in transplanted kidneys that were considered healthy showing subclinical latent IgA deposition one hour after transplantation. Methods A total of 723 transplanted kidney specimens biopsied 1 h after kidney transplantation from 2009 to 2016 at Nagoya Red Cross Hospital were examined. A total of 81 cases of IgA deposition were extracted, and 41 were ultimately studied. Double immunofluorescence staining for Gd-IgA1 and IgA was conducted to investigate the role of Gd-IgA1 in subclinical IgA deposition. Results Light microscopy findings for the 41 cases indicated only minor glomerular abnormalities. Immunofluorescence analyses revealed that all cases were positive for IgA. C3, IgG, and IgM positivity rates were 78.0%, 7.3%, and 60.9%, respectively. All 41 cases were positive for Gd-IgA1, which merged with IgA deposition in immunofluorescence double staining. IgA disappeared in 26 of 40 cases (65.0%) 1 year after kidney transplantation. In contrast, IgA redeposition was observed in three cases. Conclusion Gd-IgA1 was demonstrated in all transplanted kidneys, with latent IgA deposition noted in otherwise healthy kidneys. Deposition of Gd-IgA1 might indicate the initial stage of IgA nephropathy; however, additional factors, such as IgG deposition, are required for the ultimate development of IgA nephropathy.

Safety and utility of the alpha-replacer for treatment of intraluminal obstruction of peritoneal catheters by fibrin clots.

BACKGROUND: The Moncrief-Popovich technique of peritoneal catheter implantation has beneficial effects for peritoneal dialysis (PD) initiation. However, it might increase the risk of peritoneal catheter obstruction by fibrin clots, because the catheter is buried under the skin for several weeks to months. Effects of treatment of intraluminal occlusion of PD catheters with tissue plasminogen activator, recommended by the International Society for Peritoneal Dialysis guidelines/recommendations are reportedly limited. We investigated the effectiveness of the 'alpha-replacer' (JMS, Tokyo, Japan) for PD catheter obstruction. METHODS: We retrospectively analyzed a total of 193 patients in whom PD was initiated. PD catheters were embedded using the Moncrief-Popovich technique in 130 of these patients. We assessed the occurrence rates of peritoneal catheter obstruction and the utility of the alpha-replacer for treating intraluminal catheter occlusion by fibrin clots. RESULTS: Catheter obstruction occurred in eight cases with embedded catheters, one due to omental wrapping and the others due to fibrin clots, in which median catheter burial durations were 477 (interquartile range [IQR], 226-510) days. All catheter obstructions due to fibrin clots were successfully treated with the alpha-replacer, leading to improved catheter drainage. The median amount of contrast agent used in catheterography was 10 (IQR 9-10) mL, which did not adversely affect residual renal function. There were no complications. No recurrence occurred during the observation period (median 111, IQR 55.5-141 months). CONCLUSION: Our results suggest that treatment with the alpha-replacer is a safe and effective treatment option for intraluminal obstruction of PD catheters by fibrin clots.