scholarly journals Effect of Bacterial Infection on the Edibility of Aquatic Products: The Case of Crayfish (Procambarus clarkii) Infected With Citrobacter freundii

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoli Huang ◽  
Minghao Li ◽  
Jincheng Wang ◽  
Lili Ji ◽  
Yi Geng ◽  
...  

Aquatic products are one of the world’s essential protein sources whose quality and safety are threatened by bacterial diseases. This study investigated the possible effects of bacterial infection on the main edible part, the muscle, in the case of crayfish infected with Citrobacter freundii. The histopathological analysis confirmed that crayfish was sensitive to C. freundii and muscle was one of the target organs. The transcriptome results showed impaired intercellular junctions, downregulation of actin expression, and inhibition of metabolic pathways. Furthermore, transcriptomic results suggest that C. freundii mainly affect muscle structure and nutrition. Subsequent validation experiments confirmed structural damage and nutrient loss in C. freundii infected crayfish muscle. Besides, the spoilage tests showed that C. freundii did not accelerate muscle spoilage and the bacteria had a limited impact on food safety. Therefore, although C. freundii may not be a specific spoilage bacterium, it still affects the edible taste and nutritional value of crayfish muscle. The findings of this study might contribute to further research on C. freundii infection and provide a warning about the adverse effects of bacterial infection on aquatic products.

2021 ◽  
Author(s):  
Zhiyuan Meng ◽  
Zhichao Wang ◽  
xiaojun Chen ◽  
Yueyi Song ◽  
Miaomiao Teng ◽  
...  

Abstract As a diamide insecticide, flubendiamide is widely used and has many adverse effects on environmental organisms. In this study, bioaccumulation and toxicity effects of flubendiamide in zebrafish (Danio rerio) were studied. Specifically, the results showed that the concentrations of flubendiamide increased in the early stage and achieved steady stages at 14 days and the bioconcentration factors (BCFs) of flubendiamide in zebrafish were 1.125 - 2.011. Furthermore, flubendiamide had no significant effects on the growth phenotypes of zebrafish. However, zebrafish hepatic somatic index (HSI) of zebrafish had changed significantly with exposure. Histopathological analysis showed that exposure to flubendiamide could cause structural damage to liver tissue of zebrafish. Further physiological and biochemical analysis showed that flubendiamide could significantly change the activity of CAT and the contents of MDA and GSH in liver of zebrafish. In particular, exposure to flubendiamide could also cause significant changes in the mRNA expression levels of cell apoptosis-related genes involving p53, puma, caspase-3, caspase-9, apaf-1 and bax in liver of zebrafish. In general, these results indicated that exposure to flubendiamide could induce liver damage by inducing oxidative stress and apoptosis in liver of zebrafish. The results of this study will help to further comprehensively evaluate the safety of flubendiamide to aquatic organisms.


2019 ◽  
Vol 92 ◽  
pp. 83-90 ◽  
Author(s):  
Zhendong Qin ◽  
V. Sarath Babu ◽  
Hanzuo Lin ◽  
Yunjia Dai ◽  
Hongyan Kou ◽  
...  

1995 ◽  
Vol 16 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Homero Martínez ◽  
Andrew M. Tomkins

Diarrhoeal disease may cause, precipitate, or exacerbate protein-energy and micronutrient malnutrition through five possible mechanisms: 1) reduced food intake-reduction of food intake during diarrhoea may be due to the child's anorexia, maternal food-withholding behaviour, or both; 2) decreased absorption of nutrients-structural damage to the intestine, as well as the physical action of increased intestinal movement and reduced fluid transit time, interact to produce decreased absorption of nutrients; 3) increased catabolic losses-under the influence of the inflammatory process, diarrhoea of infectious origin induces an average daily negative nitrogen balance of 0.9 g/kg/day, as muscle protein is converted to glucose through gluconeogenesis by the liver; this glucose is used as a fuel by tissues to sustain the hypermetabolism associated with fever; 4) nutrient loss from the intestine-in diarrhoea nutrients are lost directly from the intestinal tract; 5) metabolic inefficiency due to micronutrient deficiency-the increased rate of tissue synthesis displayed by children recovering from protein-energy malnutrition may be hampered by a limited supply of nutrients from the body pool, which in turn may not be replenished fast enough by dietary intake. The two main driving forces that determine nutritional care of the sick child in the home are advice from healthcare providers (mainly physicians) and the mothers’ own beliefs; a third determinant of care is the social support network available to mothers or social pressure to act in a determined way. Therefore, health providers should be knowledgeable about appropriate feeding management of illness, and should provide sound advice to mothers. The likelihood that mothers will follow the recommendations given by the health-care system (whether formal or informal) will be greater if these conform to mothers’ cultural norms and their explanatory model of disease. Feeding practices followed in health facilities should be consistent with those advised for the mothers at home. In order to make a successful change in a given practice, culture-sensitive interventions should be used.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xinheng Zhang ◽  
Qiqi Zhao ◽  
Xiaotong Ci ◽  
Sheng Chen ◽  
Liyi Chen ◽  
...  

H9N2 subtype avian influenza virus (H9N2 AIV) is a low pathogenic virus that is widely prevalent all over the world. H9N2 AIV causes immunosuppression in the host and often leads to high rates of mortality due to secondary infection with Escherichia. Due to the drug resistance of bacteria, many antibiotics are not effective in the treatment of secondary bacterial infection. Therefore, the purpose of this study is to find effective nonantibiotic drugs for the treatment of H9N2 AIV infection-induced secondary bacterial infection and inflammation. This study proves, for the first time, that baicalin, a Chinese herbal medicine, can regulate Lactobacillus to replace Escherichia induced by H9N2 AIV, so as to resolve the intestinal flora disorder. In addition, baicalin can effectively prevent intestinal bacterial translocation of SPF chickens’ post-H9N2 AIV infection, thus inhibiting secondary bacterial infection. Furthermore, baicalin can effectively treat H9N2 AIV-induced inflammation by inhibiting intestinal structural damage, inhibiting damage to ileal mucus layer construction and tight junctions, improving antioxidant capacity, affecting blood biochemical indexes, and inhibiting the production of inflammatory cytokines. Taken together, these results provide a new theoretical basis for clinical prevention and control of H9N2 AIV infection-induced secondary bacterial infection and inflammation.


Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.


Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.


Author(s):  
J.S. Ryerse

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.


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