Distribution and drug resistance of pathogenic bacteria of biliary tract infection in patients subjected to hepatobiliary surgery / 中国基层医药

Objective:To study the distribution and drug resistance of pathogenic bacteria of biliary tract infection in patients with hepatobiliary surgery.Methods:A total of 103 patients with biliary tract infection who received treatment in the Department of Hepatobiliary Surgery, Lanxi People's Hospital from May 2020 to October 2022 were included in this study. Their bile was cultured to analyze the distribution and drug resistance of pathogenic bacteria. The data were processed using the WHONET5.5 software system.Results:Fifty-eight pathogenic bacteria-positive samples were cultured from the bile of 103 patients with biliary tract infection, with a pathogenic bacteria-positive rate of 56.31%. Among 58 strains of pathogenic bacteria, 38 strains (65.52%) were gram-negative bacteria, mainly Escherichia coli and Klebsiella pneumonia, and 5 strains (8.62%) were fungal strains. Escherichia coli and Klebsiella pneumoniae were highly resistant to sulfamethoxazole-trimethoprim, ciprofloxacin, and other antibacterial drugs, and were completely sensitive to imipenem and meropenem. Enterococcus faecalis was mainly resistant to ampicillin and penicillin G,and it was completely sensitive to vancomycin and teicoplanin. Staphylococcus aureus was resistant to vancomycin, ciprofloxacin, cefotaxime, and other drugs. A total of 13 strains of ultrabroad-spectrum beta-lactamase bacteria were isolated from 25 strains of Escherichia coli and 7 strains of Klebsiella pneumonia, with the positive detection rate of 40.63%. Conclusion:The main pathogenic bacteria of biliary tract infection are Gram-negative bacteria, which are widely distributed and have serious drug resistance. In clinical practice, antimicrobial drugs should be reasonably selected according to the results of bile drug sensitivity tests.

Construction and Characterization of Electrochemical Biosensor based on Endotoxin Aptameer / 中国生物工程杂志

A biosensor was constructed to detect the endotoxin.The amine-terminated aptamer was immobilized on the gold electrode surface covered in advance with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA).The modification of the gold electrode was confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).It was found that MPA assembly time at 6 h in the gold electrode surface to form a stable self-assembled monolayer.The biosensor has a good linear relationship with concentration of endotoxin in the range of 0.001 ～0.1 EU/ml,it is possible to be applied for quality control in the actual biological sample.

Preparation and purification of monoclonal antibodies against human chorionic gonadotrophin / 中国生化药物杂志

Purpose To prepare monoclonal antibody against hCG. Methods Balb/c mice were immunized with hCG, and spleen cells from the mice were fused with myeloma cells SP2/0 at ratio of 5:1. Positive clones were screened by indirect enzyme-linked-immunoadsorbent assay (ELISA) ,then the clones were subcloned by limiting dilution and amplified further. After intraperitoneal injection of hybridoma cells, mouse ascites antibody was prepared. Titres and specificity of the ascites antibody were identified and determined by indirect ELISA. The ascites were purified by protein A affinity chromatography. Results Two strains of hybridoma cell lines obtained could secrete MAb stably. The titre of MAb of cell culture supernate is more than 10~(-3), and the titre of prepared ascites MAb is more than 10~(-7).The purity of the obtained monoclonal antibody was more than 98% and recovery reached 75 % after purification. Conclusion The obtained two strains of hybridoma cell lines can secrete MAb stably. The monoclonal antibodies can be used in the research of early pregnancy and tumor diagnosis .

Purification of anti-HBcAg monoclonal antibodies using immobilized metal ion affinity chromatography / 生物工程学报

Anti-HBcAg monoclonal antibodies from mouse ascites were purified by using immobilized metal ion affinity chromatography. We optimized the conditions of sample loading and elution. The results showed that when the pH stepwise elution was used, the best solution for sample loading was 20 mmol/L phosphate buffer containing 0.5 mol/L sodium chloride at pH 8.0 and the mAb was eluted at pH 5.0. The purity of obtained mAb was more than 85% and recovery reached 80%. When the adsorbed proteins were eluted by using gradient elution of an imidazole, the best solution for loading condition was 20 mmolL phosphate buffer containing 5 mmol/L imidazole at pH 8.0. The purity and recovery of antibody were up to 95%.

A NEW TYPE OF BIOPESTICIDE——SPINOSYN / 微生物学通报

Spinosyns are secondary metabolites from the aerobic fermentation of saccharopolyspora spinosa Spinosyn is a kind of broad spectrum insecticide, which has contact and ingestion toxicity on insects On lepidopteran insects, spinosad (a mixture of spinosyn A and spinosyn D) is one of the most selective compounds ever discovered In this paper, the structure, biosynthesis, property and process of spinosyns are reviewed