Microbial Community Changes in Silkworms Suspected of Septicemia and Identification of Serratia sp.

Diseases that occur in silkworms include soft rot, hardening disease, digestive diseases, and sepsis. However, research on the causes of bacterial diseases occurring in silkworms and the resulting changes in the microbial community is lacking. Therefore, we examined the morphological characteristics of sepsis and changes in the microbial community between silkworms that exhibit a unique odor and healthy silkworms; thus, we established a relationship between disease-causing microorganisms and sepsis. After producing a 16S rRNA amplicon library for samples showing sepsis, we obtained information on the microbial community present in silkworms using next-generation sequencing. Compared to that in healthy silkworms, in silkworms with sepsis, the abundance of the Firmicutes phylum was significantly reduced, while that of Proteobacteria was increased. Serratia sp. was dominant in silkworms with sepsis. After bacterial isolation, identification, and reinfection through the oral cavity, we confirmed this organism as the disease-causing agent; its mortality rate was 1.8 times higher than that caused by Serratia marcescens. In summary, we identified a new causative bacterium of silkworm sepsis through microbial community analysis and confirmed that the microbial community balance was disrupted by the aberrant proliferation of certain bacteria.

Antioxidant and cholesterol regulatory effect of flavonoid-rich silk sericin.

Cholesterol is a component of cell membranes and a precursor of hormones, and excess levels are associated with disease development; therefore, it must be maintained within the normal range. Silkworm cocoons are known to contain bioactive substances. Therefore, we compared the bioactivities of pigmented and white silkworm cocoons. Sericin extract of the Yeonnokjam (YN) variety, which contained a high flavonoid content, showed the highest antioxidant activity and inhibited cholesterol biosynthetic enzyme activity. YN-fed mice showed a 26% reduction in serum low-density lipoprotein cholesterol level. In addition, a 27% decrease in cholesterol accumulation in the liver was observed. Mechanistically, YN reduced the expression of 3-hydroxy-3-methylglutaryl-CoA reductase and acetyl-CoA acetyltransferase 2 proteins by 34 and 13%, respectively. In conclusion, YN suppresses cholesterol synthesis in the liver and stimulates bile acid secretion, which contributes to reduction in cholesterol levels, suggesting its potential as a cholesterol-lowering agent.

Modulatory Effects of the Kuwanon-Rich Fraction from Mulberry Root Bark on the Renin-Angiotensin System.

In this study, we investigated the anti-hypertensive properties of mulberry products by modulating the renin-angiotensin system (RAS). Comparative analysis showed that the ethyl acetate fractions, particularly from the Cheongil and Daeshim cultivars, contained the highest levels of polyphenols and flavonoids, with concentrations reaching 110 mg gallic acid equivalent (GE)/g and 471 mg catechin equivalent (CE)/g of extract, respectively. The ethyl acetate fraction showed superior angiotensin-converting enzyme (ACE) inhibitory activity, mainly because of the presence of the prenylated flavonoids kuwanon G and H. UPLC/Q-TOF-MS analysis identified kuwanon G and H as the primary active components, which significantly contributed to the pharmacological efficacy of the extract. In vivo testing of mice fed a high-salt diet showed that the ethyl acetate fraction substantially reduced the heart weight and lowered the serum renin and angiotensinogen levels by 34% and 25%, respectively, highlighting its potential to modulate the RAS. These results suggested that the ethyl acetate fraction of mulberry root bark is a promising candidate for the development of natural ACE inhibitors. This finding has significant implications for the management of hypertension through RAS regulation and the promotion of cardiovascular health in the functional food industry.

Bombyx mori kynurenine 3-monooxygenase gene editing and insect molecular breeding using the clustered regularly interspaced short palindromic repeat/CRISPR associated protein 9 system.

Genome editing by clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR associated protein (Cas)9, a third-generation gene scissors, and molecular breeding at the genome level are attracting considerable attention as future breeding techniques. In the present study, genetic and phenotypic analyses were conducted to examine the molecular breeding of Bombyx mori through CRISPR/Cas9-mediated editing of the kynurenine 3-monooxygenase (KMO) gene. The synthesized guide RNAs (gRNAs) were analyzed using T7 endonuclease I after introduction into the BM-N silkworm cell line. To edit the silkworm gene, K1P gRNA, and Cas9 complexes were microinjected into silkworm embryos. After microinjection, the hatching rate and the incidence of mutation were determined as 18.1% and 60%, respectively. Gene mutation was verified in the heterozygous G0 generation, but no phenotypic change was observed; however, certain embryos and moths produced through sib-mating had significant differences compared to the wild-type. In successive generations, a distinct phenotypic change was also observed by continuous mating. Thus, although there are limitations in the phenotypic expression in breeding through the induction of deletion mutations, as in the present study, the process is believed to yield successful results within a shorter period compared to traditional breeding and is safer than transgenic technology.

Asymptomatic cervical isthmic spondylolisthesis and associated occult spinal bifida: a case report.

We report a case of rare cervical isthmic spondylolisthesis of C6-7 combined occult spinal bifida at C6, and review the radiologic finding, different diagnosis and treatment. A 23-year old female presented nuchal, back pain after traffic accident. Radiologic finding showed the 6(th) cervical isthmic defect, spondylolisthesis and dysplasia. The patient was conservatively treated about 8 weeks, and 10 months after injury, she was symptom free with full range of motion of cervical spine and she was followed up. Cervical spondylolysis is a very rare condition. This clinical importance is vulnerable to trauma. For whatever reasons, symptomatic patients need to be treated by conservative or surgical option.

Predictive risk factors for refracture after percutaneous vertebroplasty.

OBJECTIVE: To identify risk factors for developing a vertebral refracture after percutaneous vertebroplasty. METHOD: A retrospective analysis of 60 patients who had undergone percutaneous vertebroplasty between January 2008 and April 2010 was conducted. All patients were observed for a 1 year follow-up period, and fracture was defined when it was both clinically reported and radiographically confirmed. Twenty-seven patients with a refractured vertebra and 33 patients without a refracture were included. Of the 60 patients, 20 presented with a refracture from a cemented vertebra, whereas the remaining 40 patients did not. Clinical, imaging and procedure-related factors for each group were analyzed by the Fisher's exact, chi-square, and the Mann-Whitney U-tests. RESULTS: Local kyphotic angle and sagittal index were significant as a result of researching various risk factors related to vertebral refracture (p<0.001, p<0.001, respectively) and refracture from a cemented vertebra itself (p=0.004, p<0.001, respectively). Other factors were not significant. CONCLUSION: Patients who had a high preoperative local kyphotic angle and a high sagittal index required a close follow-up and attention.