The relationship between the characteristics of type 3 secretion system and biofilm of Pseudomonas aeruginosa in diabetic foot wound with antibiotic resistance / 中华内分泌代谢杂志

Objective:To explore the characteristics of type 3 secretion system and biofilm of Pseudomonas aeruginosa in diabetic foot wound, and to analyze the relationship between these factors, as well as to the antibiotic sensitivity.Methods:Thirty-three strains of Pseudomonas aeruginosa were collected from the foot wounds of diabetic foot inpatients in Tianjin Medical University Chu Hsien-I Memorial Hospital from February 1, 2018 to December 31, 2018. Thirteen strains of Pseudomonas aeruginosa were collected from non-diabetic wounds. All strains were tested for antibiotic sensitivity. The virulence genes exoS or exoU of Pseudomonas aeruginosa and the ability of biofilm formation were tested. The characteristics of exoS or exoU and biofilm of Pseudomonas aeruginosa were analyzed. Patients′ clinical outcomes were also analyzed.Results:Pseudomonas aeruginosa with exoS gene was the major pathogen, 90.9% found in diabetic foot group and 84.6% in control group, with no significant difference( χ2=0.54, P=0.46). The drug-resistant strains of Pseudomonas aeruginosa with exoS accounted for 16.7% in diabetic foot group and 18.2% in control group, also with no significant difference( χ2=0.18, P=0.83). There were 5 strains of Pseudomonas aeruginosa carrying exoU, 3 strains in diabetic foot group, of which 1 was resistant, 2 in control group, no resistant strain. Pseudomonas aeruginosa increased the ability of biofilm formation in diabetic foot group, accounting for 57.6%, and for resistant strains, 83.3% of them increased the biofilm formation ability. Two kinds of Pseudomonas aeruginosa produced different biofilms, but they were effectiveless for carbapenem antibiotics. The times of debridement ( P<0.01), time of antibiotic use ( P<0.01) were more in biofilm wound, but the healing rate reached 75%-90%. Conclusion:Pseudomonas aeruginosa secreting ExoS is the main one in the diabetic foot wound. The ability of Pseudomonas aeruginosa to produce biofilm in DF wound is increased. Biofilm is one reason for its antibiotic resistance. Multiple debridement combined with sensitive antibiotics is an effective method to remove biofilm.

Research on direct forming of comminuted fracture surgery orienting model by selective laser melting / 生物医学工程学杂志

In order to simplify the distal femoral comminuted fracture surgery and improve the accuracy of the parts to be reset, a kind of surgery orienting model for the surgery operation was designed according to the scanning data of computer tomography and the three-dimensional reconstruction image. With the use of DiMetal-280 selective laser melting rapid prototyping system, the surgery orienting model of 316L stainless steel was made through orthogonal experiment for processing parameter optimization. The technology of direct manufacturing of surgery orienting model by selective laser melting was noted to have obvious superiority with high speed, precise profile and good accuracy in size when compared with the conventional one. The model was applied in a real surgical operation for thighbone replacement; it worked well. The successful development of the model provides a new method for the automatic manufacture of customized surgery model, thus building a foundation for more clinical applications in the future.

THE DISTRIBUTION OF BACILLUS THURINGIENSIS AND CRY GENE DIVERSITY IN CHINA / 微生物学通报

cryⅢ gene,they were found in 75 6%,67 9%,58 4% and14 5% of the strains respectively,no cryⅠ Ⅴ gene was found,10cry gene combination types were concluded.The Bt isolates which contained cryⅠ genes were further characterized by additional PCR detection with specific primers of the cryⅠAc,cryⅠC and cryⅠE genes.20 Bt isolates which contained cryⅠAc,cryⅠC,cryⅡ and cryⅤ genes were found,among them the strain Bt\|15A3 is high toxic to Heliothis armigera,Spodoptera exigua and Plutella xylostella,and has potential developing and applying value.