A Rapid Identification Method for Germplasm Materials Resistant to Citrus Huanglongbing Disease

[Objectives]This study was conducted to develop a rapid identification method for citrus germline materials resistant to Huanglongbing disease and lay a basis for accelerating citrus breeding for resistance to Huanglongbing and increasing the breeding efficiency.[Methods]Thirty-six citrus germplasms suspected to be resistant to citrus Huanglongbing disease were collected.The method of direct high grafting to citrus trees infected with Huanglongbing pathogen was adopted.The resistance of the test materials was identified and evaluated by field symptoms combined with quantitative PCR.It was defined as the top grafting identification method.[Results]The test materials that were grafted in spring started to germinate after one month,and three months late(June 5,2018)typical mottled yellowing on leaves was observed on KH-14 for the first time.After four months(July 5,2018)of top grafting,typical mottled yellowing occurred on 23 materials,and 11 materials showed no such symptom.After six months(September 4,2018)of top grafting,although the growth of KH-18,KH-12,KHY-4,KHY-5 and KHY-6 were normal,yellowing was observed on their leaves.Only KH-21 grew well,and showed no yellow shoots and yellowing leaves.It was identified as the material with resistance to Huanglongbing disease.Quantitative PCR tests on the above six materials showed that KH-21 was negative and other five were positive.Real-time fluorescence quantitative PCR test indicated that the average Huanglongbing bacteria amount in KH-21 was 1870.0 cell/μg DNA,and the average Huanglongbing bacteria amount in the control material was 372285.5 cell/μg DNA,indicating KH-21 was resistant to Huanglongbing bacteria.[Conclusions]The method for infecting bacteria by top grafting takes six months,can detect large amount of seedlings,and is time-saving,efficient,cost-saving and accurate.This method can quickly identify the resistance of citrus varieties to citrus Huanglongbing disease,and can be popularized and used in the identification of citrus Huanglongbing disease resistance.

Copper ion/gallic acid MOFs-laden adhesive pomelo peel sponge effectively treats biofilm-infected skin wounds and improves healing quality

Bacterial infection and scar formation remain primary challenges in wound healing.To address these issues,we developed a decellularized pomelo peel(DPP)functionalized with an adhesive PVA-TSPBA hydrogel and antibacterial gallic acid/copper MOFs.The hybrid wound dressing demonstrates favorable biocompatibility.It does not impede the proliferation of fibroblasts or immune cells and can stimulate fibroblast migration,endothelial angiogenesis,and M2 macrophage polarization.Additionally,the dressing can scavenge reactive oxygen species(ROS)and provide antioxidant effects.Furthermore,DPP+MOF@Gel effectively inhibits the viability of S.aureus and E.coli in vitro and in vivo.The histological observations revealed enhanced granulation tissue formation,re-epithelialization,and angiogenesis in the DPP+MOF@Gel group compared to other groups.The local immune response also shifted from a pro-inflammatory to a pro-regenerative status with DPP+MOF@Gel treatment.The skin incision stitching experiment further exhibits DPP+MOF@Gel could reduce scar formation during wound healing.Taken together,the hybrid DPP+MOF@Gel holds great promise for treating bacteria-infected skin wounds and inhibiting scar formation during wound healing.

Epidemiological study of community- and hospital-acquired intraabdominal infections

Purpose： To investigate and analyze the clinical and etiological characteristics of community-acquired intraabdominal infections （CIAIs） and hospital-acquired or nosocomial intraabdominal infections （NIAIs） in a comprehensive hospital, to understand the characteristics, pathogen composition, and drug resistance of CIAls as well as NIAIs, and to provide a reference for clinical treatment. Methods： We collected the clinical data of patients with intraabdominal infections admitted to our hospital from June 2013 to June 2014. In vitro drug sensitivity tests were conducted to separate pathogens, and the data were analyzed using the WHONET 5.4 software and SPSS 13.0 software. Results： A total of 221 patients were enrolled in the study, including 144 with CIAls （55 mild-moderate and 89 severe） and 77 with NIAIs. We isolated 322 pathogenic strains, including 234 strains of gramnegative bacteria, 82 strains of gram-positive bacteria, and 6 strains of fungi. Based on clinical features, NIAIs and severe ClAls presented significantly higher values in age, length of hospital stay, mortality, and the incidence of severe intra-abdominal infection than mild-moderate CIAIs （p 〈 0.05）. There was no significant difference in the prognosis between NIAIs and severe CIAIs. Primary diseases leading to CIAIs and NIAIs mostly were hepatobiliary diseases and gastrointestinal diseases respectively. Bacteria isolated from various types of IAls mainly were Enterobacteriaceae; mild-moderate CIAIs mostly were mono-infection of gram-negative bacteria; NIAIs mostly were mixed infections of gram-negative and grampositive bacteria; and severe CIAls were from either type of infection. The rate of Extended Spectrum β-Lactamase-producing Escherichia coil and Klebsiella pneurnoniae was much higher in NIAIs than in CIAIs （p 〈 0.05）. The antimicrobial drug sensitivity of gram-negative bacteria isolated from NIAIs was significantly lower than that of CIAIs. Conclusion： CIAIs and NIAIs have their own unique clinical features and epidemiological features of pathogens which should be considered during the initial empiric therapy for the rational use of anti- microbial drugs. Regional IAls pathogenic bacteria have their own features in drug resistance, slightly different from some recommendations of 2010 Infectious Diseases Society of America guidelines.