Little is known about chromosome segregation in polyploid prokaryotes. In this study, whether stringent or variable chromosome segregation occurs in polyploid thermophilic bacterium Thermus thermophilus was analyzed. A stable heterozygous strain (HL01) containing two antibiotic resistance markers at one gene locus was generated. The inheritance of the two alleles in the progeny of the heterozygous strain was then followed. During incubation without selection pressure, the fraction of heterozygous cells decreased and that of homozygous cells increased, while the relative abundance of each allele in the whole population remained constant, suggesting chromosome segregation had experienced random event. Consistently, in comparison with Bacillus subtilis in which the sister chromosomes were segregated equally, the ratios of DNA content in two daughter cells of T. thermophilus had a broader distribution and a larger standard deviation, indicating that the DNA content in the two daughter cells was not always identical. Further, the protein homologs (i.e. ParA and MreB) which have been suggested to be involved in bacterial chromosome partitioning did not actively participate in the chromosome segregation in T. thermophilus. Therefore, it seems that protein-based chromosome segregation machineries are less critical for the polyploid T. thermophilus, and chromosome segregation in this bacterium are not stringently controlled but tend to be variable, and random segregation can occur.

Continuous cropping obstacles (CCOs) have increasingly become an important phenomenon affecting morel mushroom yield and quality. In this review, we summarize the current knowledge about the driving factors behind morel mushroom continuous cropping, including the increase in soil nutrients, disorder of the soil microbial structure, aggravation of diseases, and accumulation of allelochemicals and autotoxins. Furthermore, we analyze the interrelationships among these driving factors. To mitigate these adverse effects, we propose five potential strategic approaches aimed at optimizing existing interventions. This overview not only delineates the causative agents and their intricate interactions under continuous cropping scenarios but also consolidates prospective solutions to alleviate these constraints, thereby advancing our understanding and management of morel production sustainability.

Staphylococcus aureus is a common commensal of humans, and its translocation from gastrointestine to peripheral organs and tissues could cause severe diseases and complications. This study focuses on the screening and characterization of Lactobacillus strains with significant inhibitory effect on the translocation of S. aureus through Caco-2 monolayers. First, strains with strong affinity for mucin and Caco-2 cells were obtained, via microtiter plate assay and adhesion assay, respectively. Obtained bacteria were further tested for their inhibitory effects on the growth of S. aureus by well diffusion assay. Subsequently, two strains preincubated with Caco-2 monolayers were found to inhibit the translocation of S. aureus CMCC26003 by 80.95 and 43.96%, respectively, via the transcellular translocation assay. These two strains were then identified to be Lactobacillus fermentum NCU3087 and L. fermentum NCU3088. Second, the mechanism of inhibition was investigated by analyzing the relative concentration of tight junction proteins and proinflammatory cytokines of Caco-2 cells, by Western blot and enzyme-linked immunosorbent assay, respectively. Results showed that both NCU3087 and NCU3088 significantly attenuated the degradation of occludin, claudin-1, ZO-1, and JAM-1 and suppressed the secretion of interleukin 6 and tumor necrosis factor-α induced by S. aureus, to different extent. Moreover, two Lactobacillus strains could barely translocate the Caco-2 monolayers, had no hemolytic activity, displayed strong resistance to gastrointestinal fluids, and were sensitive or moderate sensitive to nine clinically relevant antibiotics. Collectively, this study identified two Lactobacillus strains with significant inhibitory effect on the translocation of S. aureus, and their safeness for application was evaluated, thereby providing potential solutions for prevention of S. aureus and prophylaxis of related diseases.

Insulin resistance, as a common metabolic disorder, may be caused by diet‑induced obesity. The aim of the present study is to investigate the effects of dioscin on regulating insulin resistance of adipose tissue induced by a high‑fat diet (HFD). An animal model was established successfully using C57BL/6J mice with high‑fat feeding, followed by treatment with 5, 10 and 20 mg/kg dioscin through gavage for 18 weeks, and randomly divided into a control group, a HFD model group and a dioscin group treated with 5, 10 and 20 mg/kg/day dioscin for 12 weeks. Histopathological changes in adipose tissues were examined using hematoxylin and eosin staining. Biochemical parameters of the serum were also monitored, including glucose, insulin, total triglyceride, homeostasis model assessment of insulin resistance (HOMA‑IR) and adipose insulin resistance (Adipo‑IR) levels. Expression of the mRNA and associated proteins of the insulin receptor substrate 1 (IRS‑1)/phosphoinositide 3‑kinase (PI3K)/protein kinase B (Akt) pathways were determined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis, respectively. HOMA‑IR and Adipo‑IR values of mice fed with a HFD were significantly higher compared with those in the control group (P<0.01). However, dioscin administration significantly decreased HOMA‑IR and Adipo‑IR values in a dose‑dependent manner (P<0.05), suggesting the effects of dioscin on attenuating insulin resistance. RT‑qPCR results indicated that the associated genes of the IRS‑1/PI3K/Akt pathway were significantly downregulated by HFD compared with the control group (P<0.05), while dioscin significantly increased the expression of those genes compared with the control group (P<0.05). Similarly, the significant increase in phosphorylated (p‑)IRS‑1/IRS‑1 (P<0.05) and p‑Akt/Akt (P<0.05) values were substantially reversed by dioscin treatment. Dioscin pronouncedly mitigated insulin resistance in adipose tissues through the IRS‑1/PI3K/Akt pathway and has potential to be used as a novel therapeutic agent for the therapy of HFD‑induced insulin resistance in adipose tissue.