Utilization of tissue habitats by Myxobolus wulii Landsberg & Lom, 1991 in different carp hosts and disease resistance in allogynogenetic gibel carp: redescription of M-wulii from China and Japan

Myxobolus wulii (=Myxosoma magna) was first described from the gills of goldfish, Carassius auratus auratus, in China. Subsequently, a myxosporean infecting the hepatopancreas of allogynogenetic gibel carp, C. auratus gibelio, was designated as a different species, Myxobolus guanqiaoensis, although the morphological features were almost identical to those of M. wulii. In Japan, an unidentified Myxobolus sp. was found in the gills and hepatopancreas of goldfish. Morphological and molecular analyses in the present study identified these myxosporeans as M. wulii, which was thus shown to use different habitats in the host fish. Phylogenetic analyses of small subunit ribosomal RNA gene sequences showed that M. wulii is closely related to two gill-infecting Myxobolus species, M. ampullicapsulatus and M. longisporus. Fish infected with M. wulii in the hepatopancreas exhibit swollen abdomens and chronic mortality. Hepatopancreas tissues are virtually destroyed and replaced with plasmodia of M. wulii. A remarkable difference in susceptibility to M. wulii between two clones of allogynogenetic gibel carp was observed, suggesting that resistance to the myxosporean infection was established in a clone of fish bred by allogynogenesis

The suppression of hematopoiesis function in Balb/c mice induced by prolonged exposure of microcystin-LR

Microcystins (MCs) cause normocytic anemia in patients in a hemodialysis unit in Caruaru, Brazil in 1996, but the underlying mechanisms are still unclear. In the present study, Balb/c mice were intraperitoneally injected with microcystin-LR (MC-LR) at the doses of 0.5, 2 and 8 mu/kg body weight (bw) every 48 h for 30d. After the prolonged exposure of MC-LR, significant decreases of red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) were observed in 2 and 8 mu g/kg bw groups, but erythrocyte mean corpuscular volume (MCV) showed no significant changes. Significantly elevated micronucleus frequency was observed in bone marrow cells (BMCs) in all MC-LR treatments. The proliferation of BMCs significantly declined in both 2 and 8 mu g/kg bw groups. Serum levels of some hematopoietic growth factors significantly changed in 8 mu g/kg bw group, mainly including granulocyte-macrophage (GM-CSF), erythropoietin (EPO), interleukin-3 (IL-3) and TNF-alpha. The transcriptional levels of these 4 genes in BMCs were also significantly changed in 8 mu g/kg bw group. MC-LR exposure significantly increased the apoptosis rates in all MC-LR treatments. The present study indicates prolonged exposure of MC-LR induces normocytic anemia, and the disturbed hematopoietic growth factors and BMCs apoptosis are responsible for this normocytic anemia. (C) 2013 Elsevier Ireland Ltd. All rights reserved.Microcystins (MCs) cause normocytic anemia in patients in a hemodialysis unit in Caruaru, Brazil in 1996, but the underlying mechanisms are still unclear. In the present study, Balb/c mice were intraperitoneally injected with microcystin-LR (MC-LR) at the doses of 0.5, 2 and 8 mu/kg body weight (bw) every 48 h for 30d. After the prolonged exposure of MC-LR, significant decreases of red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) were observed in 2 and 8 mu g/kg bw groups, but erythrocyte mean corpuscular volume (MCV) showed no significant changes. Significantly elevated micronucleus frequency was observed in bone marrow cells (BMCs) in all MC-LR treatments. The proliferation of BMCs significantly declined in both 2 and 8 mu g/kg bw groups. Serum levels of some hematopoietic growth factors significantly changed in 8 mu g/kg bw group, mainly including granulocyte-macrophage (GM-CSF), erythropoietin (EPO), interleukin-3 (IL-3) and TNF-alpha. The transcriptional levels of these 4 genes in BMCs were also significantly changed in 8 mu g/kg bw group. MC-LR exposure significantly increased the apoptosis rates in all MC-LR treatments. The present study indicates prolonged exposure of MC-LR induces normocytic anemia, and the disturbed hematopoietic growth factors and BMCs apoptosis are responsible for this normocytic anemia. (C) 2013 Elsevier Ireland Ltd. All rights reserved

Screening for and Identification of an Anti-clam Vibrio Marine Bacterium from an Aquaculture Pond in the Yellow Sea

The identification and use of probiotic bacterial stains is a practical approach to protect clams grown in aquaculture farms from disease. The inhibition of the pathogenic bacterium Vibrio alginolyticus was used as a trait to select a candidate probiotic bacterial strain in this study. An ideal bacterial strain, SW-1, was isolated from seawater from a clam farm. The selected isolate SW-1 was identified based on its physiological, morphological, and biochemical characteristics and its 16S rDNA sequence. The experiments showed that strain SW-1 had a high similarity to Pseudoalteromonas piscicida and could inhibit the growth of V. alginolyticus (V.-MP-1). SW-1 also improved the survival of clams following challenge with the pathogenic V.-MP-1. The mortality of clams was 100% after infection with 10(8) CFU/mL of V. alginolyticus, whereas mortality was only 11% when clams were infected with 10(8) CFU/mL of V.-MP1 while simultaneously exposed to the same concentration of Pseudoalteromonas SW-1, indicating that Pseudoalteromonas SW-1 could be used as a probiotic to protect farmed clams, and thus reduce the effects of antibiotics on aquatic environment

Evaluation of semi-arid arable soil heavy metal pollution by magnetic susceptibility in the Linfen basin of China

The values of magnetic susceptibility and Cu, Zn, Ni, Pb, Cr, Cd concentrations of 70 topsoil samples were analyzed and assessed for soil contamination in the Linfen basin of China. The contamination factor (CF) and pollution load index (PLI) were used to assess the degree of heavy metal pollution. All heavy metal concentrations in the soil were greater than the background values of Shanxi agricultural soils. PLI values ranged from 1.27 to 2.18 indicating significant soil contamination. Principal component analyses and correlation analyses were adopted for data treatment to identify heavy metal sources. Cu, Zn, Ni, and Pb were responsible for 31.2% of the total variance suggesting that these elements mainly originated from agrochemistry and atmospheric deposition. A positive correlation of magnetic susceptibility with Cu and PLI were observed in cultivated soils. This study shows that magnetic susceptibility measurements can be used as a technique in which different types of soil pollution can be distinguished and can also be used to rapidly monitor anomalies in areas that might require expensive and time consuming detailed chemical analyses