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In this study, a new Bacillus velezensis strain Bv-303 was identified and its biocontrol effect against rice bacterial-blight (BB) disease caused by Xanthomonas oryzae pv. oryzae (Xoo) was investigated. Cell-free supernatant (CFS) of strain Bv-303 under different growth conditions were prepared to test the antagonistic activity and stability against Xoo by the Oxford-cup method in vitro. The antibacterial effect of strain Bv-303 to BB disease in rice were further analyzed in vivo by spraying the cell-culture broth (CCB), CFS and cell-suspension water (CSW), respectively, on the rice leaves inoculated with Xoo. Additionally, rice seeds germination rate and seedling growth under the strain Bv-303 CCB treatment were tested. The results showed that the strain Bv-303 CFS significantly inhibited Xoo growth by 85.7%‒88.0% in vitro, which was also stable under extreme environment conditions such as heat, acid, alkali and ultraviolet light. As tested in vivo, spraying the CCB, CFS or CSW of strain Bv-303 on the Xoo-infected leaves enhanced rice plant resistance to BB disease, with CCB showing the highest increase (62.7%) in disease-resistance. Notably, CCB does not have negative effects on rice seed germination and seedling growth. Therefore, strain Bv-303 has great potential for biocontrol of the rice BB disease.
Subject(s)
Oryza , Fatigue Syndrome, Chronic , Bacillus , Xanthomonas , Plant Diseases/microbiologyABSTRACT
Background@#Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. @*Objectives@#We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. @*Methods@#In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. @*Results@#The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. @*Conclusions@#In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.
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Background@#Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. @*Objectives@#We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. @*Methods@#In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. @*Results@#The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. @*Conclusions@#In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.
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Background@#Pseudorabies, also known as Aujeszky's disease, is caused by the pseudorabies virus (PRV) and has been recognized as a critical disease affecting the pig industry and a wide range of animals around the world, resulting in great economic losses each year. Shandong province, one of the most vital food animal-breeding regions in China, has a very dense pig population, within which pseudorabies infections were detected in recent years. The data, however, on PRV epidemiology and coinfection rates of PRV with other major swine diseases is sparse. @*Objectives@#This study aimed to investigate the PRV epidemiology in Shandong and analyze the current control measures. @*Methods@#In this study, a total number of 16,457 serum samples and 1,638 tissue samples, which were collected from 362 intensive pig farms (≥ 300 sows/farm) covered all cities in Shandong, were tested by performing enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). @*Results@#Overall, 52.7% and 91.5% of the serum samples were positive for PRV-gE and -gB, respectively, based on ELISA results. In addition, 15.7% of the tissue samples were PCR positive for PRV. The coinfection rates of PRV with porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus, and classical swine fever virus were measured; coinfection with PCV2 was 35.0%, higher than those of the other two viruses. Macroscopic and microscopic lesions were observed in various tissues during histopathological examination. @*Conclusions@#The results demonstrate the PRV prevalence and its coinfection rates in Shandong province and indicate that pseudorabies is endemic in pig farms in this region. This study provides epidemiological data that can be useful in the prevention and control of pseudorabies in Shandong, China.
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Objective To compare the central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) in healthy pregnant women and patients with pre-eclampsia.Methods A prospective control study.Twenty normal subjects,20 healthy pregnant women and 20 patients with pre-eclampsia were included.The difference of gestational weeks between healthy pregnant women and patients with pre-eclampsia was not significant (x2=0.012,P=0.913).The differences of age and spherical equivalent among normal subjects,healthy pregnant women and patients with pre-eclampsia were not significant (x2=1.760,0.087;P=0.413,0.957).All eyes underwent optical coherence tomography examination to measure the CFT and SFCT.Results The mean CFT of normal subjects,healthy pregnant women and patients with pre-eclampsia were (194.40± 16.17),(201.2±17.33),(199.00±15.46) μm,there was no significant difference among the three groups (x2=0.888,P=0.641).The mean SFCT of normal subjects,healthy pregnant women and patients with pre-eclampsia were (263.45±69.66),(330.00±49.20),(373.40±52.00) μm,there was significant difference among the three groups (x2=22.818,P=0.000).The mean SFCT of healthy pregnant women was increased than that of normal subjects (Z=-2.991,P=0.002).The mean SFCT of patients with pre-eclampsia was increased than that of healthy pregnant women (Z=-2.638,P=0.007).Conclusion The mean SFCT of patients with pre-eclampsia is increased than healthy pregnant women.
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BACKGROUND:The inflammatory cytokines,produced by synovial cells and invaded monocytes/macrophages and lymphocytes in synovial tissues of rheumatoid arthritis(RA),play a major role in rheumatoid synovial pathology.Interleukin(IL)-17,a recently found inflammatory cytokine,associates with many autoimmune diseases.OBJECTIVE:To detect IL-17 level Levels of interleukin-17 in serum of rats with collagen-induced arthritis(CIA),to study the relationships among IL-17 and the arthritis index,IL-1?,tumor n?ecrosis factor?(TNF-?),as well as matrix meralloproteinase 3(MMP-3).DESIGN,TIME AND SETTING:A randomized controlled animal trial was performed in the Immunology Laboratory of Medical College of Dalian University from March to August 2008.MATERIALS:Fifty female,inbred Wistar rats,aged 4-6 weeks,with average weight of(180?15) g.METHODS:Forty out of 50 rats were randomly selected for establishing CIA models.The other 10 rats were regarded as the normal control group.Rats in CIA group were injected intradermally 200 ?L emulsified type-II collagen at the base of the tail after model preparation.At day 7,a second boosted injection of emulsified CII in 100 ?L was administered at the base of the tail.The rats in normal controls were injected with the same dose of saline.MAIN OUTCOME MEASURES:Paw swelling was observed at 24 hours after immunization;The levels of IL-17,IL-1?,?T?NF-? a?nd MMP-3 were examined by ELISA;The inflammatory index of CIA rats was observed.RESULTS:The levels of IL-17,IL-1?,TNF-?,as well as MMP-3 in the CIA group was greater than that of the control group(all P
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To solve the problem of two separating lobes in a child's pulmonary surgery, this paper introduces the design, manufacture and clinical application of the bronchus blocking tube, which can better ensure patients' safety when anaesthetized.