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Vibrio vulnificus is an important foodborne pathogenic bacterium that mainly contaminates seafood. Rapid and accurate technologies that suitable for on-site detection are critical for effective control of its spreading. Conventional detection methods and polymerase chain reaction (PCR)-based and qPCR-based approaches have application limitations in on-site scenarios. Application of loop-mediated isothermal amplification (LAMP) technology was a good step towards the on-site detection. In this study, a recombinase polymerase amplification (RPA)-based detection method for V. vulnificus was developed combining with lateral flow strip (LFS) for visualized signal. The method targeted the conservative empV gene encoding the extracellular metalloproteinase, and finished detection in 35 min at a conveniently low temperature of 37 °C. It showed good specificity and an excellent sensitivity of 2 copies of the genome or 10−1 colony forming unit (CFU) per reaction, or 1 CFU/10 g in spiked food samples with enrichment. The method tolerated unpurified templates directly from sample boiling, which added the convenience of the overall procedure. Application of the RPA-LFS method for clinical samples showed accurate and consistent detection results compared to bioassay and quantitative PCR. This RPA-LFS combined method is well suited for on-site detection of V. vulnificus. • A recombinase polymerase amplification-based detection method for Vibrio vulnificus. • Detection finishes in 35 min at a conveniently low temperature of 37 °C. • The method exhibited good specificity and sensitivity. • A rapid, simple and reliable method well suited for on-site detection. [ABSTRACT FROM AUTHOR]

Abstract Baseflow is the portion of streamflow that originates from groundwater. It is pivotal to groundwater supply as well as the interactions between groundwater and surface water. In the Loess Plateau of China, the baseflow plays a fundamental role in sustaining the aquatic ecosystem. Rational estimation of baseflow is of critical importance for understanding the functioning of the groundwater system and informing management of regional water resources. In this study, a two-well parameterised digital filter was used to separate baseflow from observed daily total streamflow on the Weihe River Basin. Two parameters (maximum baseflow index (BFI max) and the recession constant) of this filter were estimated using UKIH and a recession analysis with physical meaning, respectively. The results show that the baseflow index increased from the upstream to downstream (0.27–0.32) of the Weihe River, and the baseflow of the river is summer dominant. In general, the baseflow has been increasing gradually owing to the implementation of soil conservation measures. This study provides an understanding of baseflow response to seasonal variability and water environmental management in basin scale. Highlights • The baseflow in the loess regional catchment with the spatial attributes. • Baseflow shows a gradually increasing trend from upstream to downstream in the Weihe River Basin. • The baseflow of this river is dominated by summer baseflow. [ABSTRACT FROM AUTHOR]

Vibrio alginolyticus is an important zoonotic marine pathogenic bacterium. Previous studies on the mechanism of innate immune against V. alginolyticus infection have been limited to aquatic animals, however, how V. alginolyticus activates mammalian immune cells has not been fully clarified. Here, ELISA combined RT-qPCR assays were used to detect the secretion and transcription level of pro-inflammatory cytokines and TLRs during V. alginolyticus infection of mice peritoneal macrophages (PMϕs). Western blotting was used to explore the phosphorylation levels of p38, JNK, ERK, AKT and NF-κB protein. Immunofluorescence assay was used to determine the location of NF-κB protein. Inhibition assay was used to study the role of up-regulated TLR in activated signaling pathways and the role of these pathways in the release of pro-inflammatory cytokines. Our data showed that V. alginolyticus can up-regulate the expression levels of IL-1β, IL-6, IL-12 and TNF-α in PMϕs. In addition, V. alginolyticus stimulation activated the phosphorylation of p38, JNK and ERK were TLR2 heterodimers-dependent, whereas inhibitors of SB203580 (p38), SCH772984 (ERK) and SP600125 (JNK) significantly reduced IL-1β, IL-6, IL-12 and TNF-α production. We further revealed that V. alginolyticus activated the signaling pathways of AKT via TLR2 heterodimers. The inhibitor of MK-2206 2HCl (AKT) negatively regulated the IL-1β, IL-6 and TNF-α release levels. Moreover, V. alginolyticus infection of PMϕs resulted in TLR2 heterodimers-mediated activation of NF-κB and induced translocation of phosphorylated NF-κB protein from the cytoplasm into the nucleus via IκBα degradation. V. alginolyticus induced IL-1β, IL-6, IL-12 and TNF-α release were blocked by the specific NF-κB inhibitor, BAY 11–7082. Taken together, our results suggested that activation of the TLR2 heterodimers-mediated downstream signaling pathways NF-κB, MAPK and AKT is responsible for inflammatory response during Vibrio alginolyticus infection in vitro. • V. alginolyticus activate TLR2-mediated MAPK, AKT and NF-κB pathways in mouse PMϕs. • V. alginolyticus activate MAPK and NF-κB pathways to enhance inflammatory response. • Cytokines levels are negatively regulated by AKT pathway in infected PMϕs. [ABSTRACT FROM AUTHOR]

Crabs are among the most important benthos in intertidal marshes. Numerous studies have shown that they can influence soil properties and soil-surface water exchange through bioturbation. However, little is still known about the effects of crab burrows on sediment microbes. In this study, we examined the effects of crab burrows on the community structure and interaction pattern of soil microbes in sediments in an intertidal marsh of the Yellow River Delta, north China using high-throughput sequencing and co-occurrence network analyses. Results showed that crab bioturbations altered soil microbial community composition both within the fungal and bacterial communities. Network analyses results indicated that the modularity of fungal networks decreased after crab bioturbation. Further, bacterial and fungal functional predictions indicated the relative abundances were significantly lower for fungal saprotrophs and saprotroph-pathotrophs in the soil mound sediment, while significantly higher for bacterial chemoheterotrophs and aerobic chemoheterotrophic in the burrow wall sediment. Our results demonstrate that crab bioturbation can modify the microbial community structure and function, and thus nutrient cycling through degradation of organic matter, a key ecosystem processes in intertidal marsh. • Crab bioturbations altered soil fungal and bacterial communities. • The modularity of soil fungal networks decreased after crab bioturbations. • Crab bioturbations changed abundance of soil bacterial and fungal functional group. [ABSTRACT FROM AUTHOR]