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Objective To investigate the distribution and drug resistance of pathogenic bacteria for infection after liver transplantation, and to provide a scientific basis for the rational clinical application of antibiotics. Methods The pathogenic bacteria isolated from the specimens of 904 patients with infection after liver transplantation in The Affiliated Hospital of Qingdao University from March 2014 to December 2021 were analyzed in terms of distribution and drug resistance. WHONET 5.6 software was used to perform a statistical analysis of strains and bacterial resistance rate, and Excel was used to analyze the sources of specimens, composition ratios, and distribution of pathogenic bacteria. Results A total of 2 208 non-repetitive pathogenic bacteria were isolated, mainly from the specimens of respiratory tract (31.25%), bile (22.28%), ascites (13.18%), blood (8.38%), and drainage fluid (4.62%). The top 10 pathogenic bacteria were Klebsiella pneumoniae subspecies (10.69%), Enterococcus faecium (10.42%), Escherichia coli (8.24%), Pseudomonas aeruginosa (8.24%), Staphylococcus epidermidis (8.06%), Acinetobacter baumannii (7.93%), Stenotrophomonas maltophilia (6.61%), Enterobacter cloacae (3.22%), Staphylococcus haemolyticus (3.08%), and Staphylococcus aureus (2.94%), accounting for 69.43% of the total pathogenic bacteria. Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Klebsiella pneumoniae subspecies, and Acinetobacter baumannii were the main pathogenic bacteria isolated from respiratory tract specimens; Enterococcus faecium was the main pathogenic bacterium isolated from bile, ascites, and drainage fluid specimens; Escherichia coli , Staphylococcus epidermidis , and Klebsiella pneumoniae subspecies were the main pathogenic bacteria isolated from blood specimens. Drug sensitivity data showed that Enterobacterales bacteria had a relatively high resistance rate to cephalosporins and fluoroquinolones and a resistance rate of 50% to macrolides, fluoroquinolones, sulfonamides, and lincomycin, and a small part of these strains were resistant to linezolid and quinupristin/dalfopristin (< 3%), with no Staphylococcus epidermidis strains resistant to tigecycline and vancomycin. A total of 287 drug-resistant strains were monitored, accounting for 13%, among which there were 128 carbapenem-resistant Acinetobacter baumannii strains, 88 carbapenem-resistant Pseudomonas aeruginosa strains, 26 carbapenem-resistant Klebsiella pneumoniae subspecies strains, 11 carbapenem-resistant Escherichia coli strains, 23 methicillin-resistant Staphylococcus aureus strains, and 11 vancomycin-resistant Enterococcus strains. The carbapenem-resistant Klebsiella pneumoniae subspecies strains mainly produced serine carbapenemase, and the carbapenem-resistant Escherichia coli strains mainly produced metal β-lactamase. Conclusion Gram-negative bacteria are the main pathogenic bacteria for infection after liver transplantation, and there are differences in the distribution of pathogenic bacteria between different types of specimens. The resistance rate of some strains tend to increase, and therefore, it is necessary to strengthen the management of nosocomial infection and antibiotics.
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Objective To explore whether exendin-4 inhibits AR42J cells and its mechanism.Methods AR42J cells were treated with exendin-4 under multiple concentrations(1,5,10 pmol/L) at 24,48,72,96,120 h to assess its cell viability by MTT assay and got the IC-50 and time points.Then checking whether exendin-4 could induce the AR42Jcells apoptosis by setting normal control (NC) group,exendin-4 (Ex-4) group and Ex-4+ z-VAD-fmk (apoptosis inhibitor) group,and exploring whether 3-MA which is autophagy inhibitor could inhibit the AR42J cells apoptosis induced by exendin-4 by setting NC group,Ex-4 group and Ex-4+3-MA group.Cell viability was analyzed by MTT and the cells apoptosis was detected by flow cytometry and the protein levels of caspase-3,LC3 and p62 were studied by Western blot.Results Concentration of 10 pmol/L exendin-4 and and time point 72 h were selected for the further study.z-VAD-fmk pretreatment can significantly inhibit the cell viability of exendin-4 by (81.2±3.3)％ vs.(49.4±3.0)％ (P＜0.05).Flow cytometry showed that exendin-4 could induce the AR42J cells apoptosis by (28.2± 1.4)％ vs.(3.6±0.8)％,and increased the caspase-3 level by Western blot,which both can be reversed by (79.1 ±2.3) ％ vs.(49.8±2.5)％ (P＜0.05) when the cells were treated for 72 h,as was apoptosis ratio by (14.5±2.1)％ vs.(29.2±3.2)％.Western blot showed that exendin-4 can upregulate protein levels of LC3B-Ⅱ,p62 和 caspase-3 and 3-MA,and pretreatment can inhibit the upregulation of LC3B-Ⅱ and caspase-3 but further increased the upregulation of p62 induced by exendin-4.Conclusions Exendin-4 can induce AR42J cells apoptosis and 3-MA pretreating can inhibit exendin-4 cytotoxicity through downregulating autophagy.So auto phagy inhibitor 3-MA could potentially extenuate the cytotoxicity of exendin-4 in pancreatic acinar cells.
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Objective To examine the expression and analyze the significance of autophagy-related gene microtubule-associated protein 1 light chain 3 (MAP1-LC3,LC3),p62 and lysosorne-associated membrane protein 2 (LAMP-2) in pancreatic tissues of mice with acute pancreatitis (AP).Methods Twenty mice were randomized into AP group and control group,and the number of mice was equal between two groups.AP group was intra-peritoneally injected by 20％ L-arginine solution (two injections of 4 g/kg body weight,every 1 h) in the dosage of 4 g/l kg twice every 1 hour to establish AP model,while control group was administered with equal volume of normal saline by intra-peritoneal injection.All the mice were euthanized at 24 hour after the last injection.Pancreatic histopathological changes were measured.In addition,the protein expressions of LC3,p62 and LAMP-2 were detected by Western blot.Results No obvious pathological changes were observed in control group.Pancreatic acinar edema,structure destruction,missing,the obvious widening of interlobular septum,small interlobular septum and acinar septum,and the necrosis of acinar cells at different degrees were observed in AP group.The pathological score for tissue edema,hemorrhage,necrosis and inflammation in AP group was 3.13 ± 0.50,2.83 ± 0.32,3.25 ± 0.46 and 3.16 ± 0.47,respectively,which was all 0 in control group.The differences were statistically significant between AP group and control group (P ＜ 0.01).In AP group,the ratio of LC3-Ⅱ/LC3-Ⅰ,p62 and LAMP-2 protein in pancreatic tissue were 1.16 ± 0.08,0.94 ± 0.04 and 0.35 ± 0.04,respectively,which were 0.24 ± 0.02,0.34 ± 0.03 and 0.95 ± 0.03 in control group.The ratio of LC3-Ⅱ/LC3-Ⅰ and p62 protein in pancreatic tissue in AP group were much higher than those in control group,while LAMP-2 in AP group was lower than that in control group,and there was statistically significant difference between two groups (all P ＜0.01).Conclusions Intraperitoneal injection of L-arginine could induce acute pancreatitis,and autophagy is impaired,which was associated with decreased LAMP-2 protein expression.
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Objective To explore the alteration and effect of autophagy in pancreas tissue of rat injected by exenatide.Methods Diabetes model rats were induced by two-month high-sugar and high-fat diet and streptozotocin injection (35 mg/kg) in normal rats.50 SD male rats were divided into four groups according to the principle of complete random design,namely normal control group (n=10),normal exenatide-injected group (n=10),diabetes-model control group (n=l5) and diabetes-model exenatide-injected group (n=15).Rats in exenatide-injected groups were subcutaneously injected with exenatide respectively in 5 μg/kg dose each time,twice a day,at 8 a.m.and 6 p.m.Animal weights were weighted weekly and the dose of exenatide was adjusted according to current weight.Rats in the two control groups were injected with the corresponding amount of saline.Mter 10 weeks of treatment,all rats were killed and pancreatic tissues were disposed.Immunohistochemistry was used to measure the expression of GLP-1R in pancreatic tissues.Western blot was used to test the expressions of LC3-Ⅰ,LC3-Ⅱ and p62 in pancreatic tissues,and LC3-Ⅱ/Ⅰ ratio and p62 were compared between any two groups.All specimens were stained with hematoxylin-eosin (HE).The data were expressed as means ± standard deviation and were analyzed by unpaired Student t test using SPSS 18.0 statistics software.P value ＜0.05 was considered to be statistically significant for all tests.Results The pancreatic tissues from 13 rats (6 from the normal exenatide-injected group and 7 from the diabetes-model exenatide-injected group) appeared pathological changes such as gland structure damage,pancreatic cells atrophy and cells compartment broadening.The expressions of GLP-1R,LC3-Ⅱ and p62,and LC3B-Ⅱ/Ⅰ ratio in the two exenatide-injected groups were higher than those in the respective control group,and the differences had statistical significance (P＜0.05).Conclusions Long-term subcutaneous injection of exenatide can upregulate the expression of GLP-1R in rat pancreatic acinar cells and may induce the impaiment of autophagy flux in rat pancreatic cell.