Bacterial biofilms are associated with at least 80% of human bacterial infections. The clinical treatment of biofilm infection is still arduous, and therefore many new treatment options are under study, such as probiotics and their derivatives, quorum sensing inhibitors, antimicrobial peptides, phage therapy, organic acids, light therapy, and plant extracts. However, most of these schemes are not mature, and it is important to develop new research directions of anti-biofilms.
ObjectiveTo investigate the condensate pollution in the pipeline of severe pneumonia patients undergoing mechanical ventilation.MethodsFrom January 2017 to January 2019, 120 patients with severe pneumonia treated by mechanical ventilation in our hospital were collected continuously. The lower respiratory tract secretions were collected for bacteriological examination. At the same time, the condensed water in the ventilator exhaust pipe was collected for bacteriological examination at 4, 8, 12, 16, 20 and 24 hours after tracheal intubation and mechanical ventilation. The bacterial contamination in the condensed water at different time points was analyzed and separated from the lower respiratory tract. The consistency of bacteria in secretion and drug resistance analysis of bacterial contamination in condensate water were carried out.ResultsOf the 120 patients with severe pneumonia after mechanical ventilation, isolates were cultured in the lower respiratory tract secretions of 102 patients. One strain was cultured in 88 cases, two strains were cultured in 10 cases, and three strains were cultured in 4 cases. The isolates were mainly Gram-negative bacteria (57.5%) and Gram-positive bacteria (42.5%). The most common isolates were Pseudomonas aeruginosa, Staphylococcus aureus and Acinetobacter baumannii. The contamination rate of condensate water was 5.0% at 4 hours, 37.5% at 8 hours, 60.0% at 12 hours, 76.7% at 16 hours, 95.0% at 20 hours, and 100.0% at 24 hours, respectively. The bacterial contamination rate in condensate water at different time points was statistically significant (P=0.000). The pollution rate at 4 hours was significantly lower than that at 8 hours (P=0.000). Gram-negative bacteria accounted for 57.5% and Gram-positive bacteria accounted for 42.5%. The most common isolates were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The consistency of bacteria in lower respiratory tract and condensate water was 83.3% in severe pneumonia patients undergoing mechanical ventilation. The overall resistance of Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus was higher, but the resistance to imipenem/cilastatin was lower.ConclusionsThe bacterial contamination in the condensate of patients with severe pneumonia during mechanical ventilation is serious. The pollution rate is low within 4 hours. It is consistent with the bacterial contamination in lower respiratory tract and the bacterial resistance is high.
目的：为临床合理应用抗生素提供依据。方法：采用VITEK 32及GNS--120药敏卡、GPS -107药敏卡进行细菌的鉴定及药敏实验。结果：320 株病原菌中，革兰氏阳性菌占28.75 %，革兰氏阴性菌占71.25 %，其中大肠埃希菌、铜绿假单胞菌、鲍曼复合醋酸钙不动杆菌、阴沟肠杆菌、金黄色葡萄球菌是临床上主要致病菌。结论：临床应科学合理选用抗生素，尽量减少和延缓耐药菌的发生及发展。
ObjectiveTo investigate the diagnostic value of products triggered by endotoxin including cytokines and procalcitonin for differentiating bacterial pneumonia from pulmonary tuberculosis. MethodsFifty patients diagnosed to have hospital-acquired pneumonia and another 50 patients diagnosed with tuberculosis admitted into West China Hospital between January and August 2015 were recruited in this study. The frequencies of CD4+ interferon (IFN)-γ+, CD4+ tumor necrosis factor (TNF)-α+, CD4+ interleukin (IL)-2+, CD4+ IL-10+ as well as CD8+IFN-γ+, CD8+TNF-α+, CD8+IL-2+, CD8+IL-10+ populations in peripheral blood were detected by flow cytometry after endotoxin stimulation. Meanwhile, the levels of procalcitonin, IL-6 and C reactive protein were measured by immunofluorescence staining. ResultsThe frequencies of CD4+ IFN-γ+, CD4+ TNF-α+, CD4+ IL-2+, CD4+ IL-10+ as well as CD8+ IFN-γ+, CD8+ TNF-α+, CD8+ IL-2+, CD8+ IL-10+ populations in the pneumonia group increased significantly compared with those in the tuberculosis group (P < 0.05). The levels of procalcitonin, IL-6 and C-reactive protein in the pneumonia group increased statistically compared with the counterparts in the tuberculosis group (P < 0.05). The positive rates of procalcitonin, IL-6 and C-reactive protein in the pneumonia group were significantly higher than those in the tuberculosis group (P < 0.05). ConclusionMeasurement of products triggered by endotoxin is beneficial for differential diagnosis of pneumonia from tuberculosis.
Objective To evaluate the rapid diagnosis of bacterial and (or) fungal endophthalmitis by multiplex polymerase chain reaction (MPCR). Methods MPCR was performed to detect the DNA segment of bacteria and (or) fungi from standard strains and 41 samples of intraocular fluid or vitreous from 38 patients (3 with double eyes and 35 with single), and the results were compared with the cultured bacteria and fungi. Results Five hours after detected by MPCR, bacteria and (or) fungi in 34 out of 41 samples (82.9%) from patients were detected，in cluding bacteria in 26，fungi in 6，and both bacteria and fungi in 2. The positive rate of MPCR was obviously higher than the cultured ones（χ2＝9.60, P＜0.05）. Conclusion With the advantages of rapidity, sensibility, and specificity, MPCR can make for the rapid and definitive diagnosis of bacterial and (or) fungal endophthalmitis. (Chin J Ocul Fundus Dis，2004，20：81-83)
ObjectiveTo study the current situation and influencing factors of biofilm formation of digestive endoscopy in Zhongshan Hospital, Fudan University.MethodsFrom September 1st to 13th, 2020, ATP fluorescence assay and membrane filtration method were carried out on 130 endoscopes from the Endoscopy Center of Zhongshan Hospital, Fudan University. The type, number, source, duration of use and disinfection times in the past week were collected. Positive culture samples were identified by matrix-assisted laser desorption / ionization time of flight mass spectrometry. Logistic regression analysis was used to explore the factors affecting the formation of biofilms.ResultsThe total qualified rate of ATP assay and bacterial culture was 94.62% and 92.31% respectively. The 10 positive culuture samples were mainly composed of Pseudomonas aeruginosa, Moraxella osloensis, Stenotrophomonas maltophilia, Pseudomonas putida and Micrococcus luteus. Multivariate logistic regression analysis showed that the frequency of disinfection in the past week was associated with positive biofilm culture (P=0.001). The odds ratio of disinfection frequency more than 30 times in past week compared with disinfection frequency less than 15 times was 0.040, and 95% confidence interval was (0.005, 0.295).ConclusionsThe biofilm of digestive endoscopy in the Endoscopy Center of Zhongshan Hospital, Fudan University is mainly formed by aquatic bacteria. The formation biofilm can decrease by increasing disinfection frequency, and attention should be paid to the monitoring of endoscopic biofilm in the future.
Objective To evaluate the clinical efficacy and safety of domestic cefepime in the treatment of acute bacterial lower respiratory tract infection. Methods A randomized, single-blind, controlled clinical trial was performed. The positive control was imported cefepime. The dosages of cefepime were 1g for moderate infection and 2g for severe infection, twice a day intravenously. The duration of the treatment was 7-10 days. Results Thirty-one patients were enrolled in the trial, of whom 30 were evaluable (15 in the triagroup and 15 in the control group). No significant differences were observed between the trial group and the control group with respect to the cure rate (40% vs. 27%), the effective rate (80% vs. 87%), the bacterial clearance rate (92% vs. 100%), and the incidence of adverse drug reactions (12.5% vs. 13%) (Pgt;0.05). Conclusion Domestic cefepime injection is effective and safe in the treatment of acute bacterial lower respiratory tract infection.