Objective To be expressed human vascular endothelial growth factor (VEGF) recombinant protein in Escherichia Coli in high level. Methods VEGF was amplified from human fetal brain cDNA library, the amplified fragment was inserted into M13mP18 and confirmed to be VEGF165cDNA by restriction mapping and DNA sequencing, then it was combined with an expression vector PRL621. This recombinant plasmid overexpressed a 20kd recombinant protein in E.Coli(TG1), the protein was isolated and purifed from E.Coli, and initially renatured. Results The overexpressed recombinant protein was 35% of the total cell protein, the sequence of its first 15-N terminal amino acid was identrical to that of the human natural VEGF protein, Chorioallantoic membrane(CAM) assay showed that the rhVEGF promated new capillary vessels formation. Conclusion The genetic engineering Escherichia Coli can express human vascular endothelial growth factor in high level.
Since the outbreak of coronavirus disease 2019, hospital laboratories have become an important place for testing all kinds of specimens of patients with suspected or confirmed coronavirus disease 2019. There may be a high load of severe acute respiratory syndrome coronavirus 2 in clinical specimens of confirmed patients, and the biosafety risk is high, so it poses a challenge to the hospital laboratory testing process. This paper compares the microbial pre-processing, culture, identification and drug sensitivity analysis of the traditional clinical microbial detection process and the fully automated microbial pipeline, expounds the biosafety risks of the traditional manual detection process of pathogenic microorganisms in the epidemic situation, and discusses the role and dilemma of the fully automated microbial pipeline in the biosafety assurance of the epidemic situation. The purpose is to provide a basis for the promotion of fully automated microbial pipeline in the future.
Objective To compare the infection characteristics and pathogen resistance between dialysis and non-dialysis patients with chronic kidney disease (CKD) in West China Hospital of Sichuan University, and provide a reference for clinical diagnosis and treatment. Methods The clinical data of CKD patients with non-repeated etiological evidence admitted to West China Hospital of Sichuan University between January 2010 and December 2021 were retrospectively analyzed. The patients were divided into dialysis group and non-dialysis group according to treatment methods. The infection characteristics and pathogen resistance of the two groups were analyzed by WHONET 5.6 and SPSS 23 softwares. Results A total of 1387 patients with CKD with positive etiology were included, excluding coagulase-negative Staphylococcus, which was common contamination pathogens of bloodstream infections. There were 527 patients in the dialysis group and 860 patients in the non-dialysis group in this study. There was no significant difference in gender between the two groups (P>0.05). There were significant differences in age, disease stage and specimen type between the two groups (P<0.01). The pathogenic bacteria samples of dialysis patients were mainly blood (25.81%) and dialysate (44.02%), and Staphylococcus aureus was the main pathogenic bacteria. In the non-dialysis group, sputum (49.88%) and urine (35.47%) were the main contents. In main Gram-positive pathogens, there were high resistance rates to penicillin and cephalosporin, and high sensitive rates to vancomycin and linezolid. In Gram-negative pathogenic bacteria, there were high resistance rates to penicillins, the first generation cephalosporins and the third generation cephalosporins, and high sensitive rates to β-lactamase inhibitor compound preparation, the fourth generation cephalosporins and other antibiotics. Conclusions CKD patients are easy to be complicated with infections. In clinical practice, it is necessary to pay attention to pathogen culture results, and selectively use antibiotics based on drug sensitivity results. At the same time, medical staff in hemodialysis centers should pay attention to aseptic operation and hand hygiene to reduce the risk of concurrent infection in dialysis patients.
Objective To analyze the species distribution and resistance of the pathogens isolated fromblood cultures of the patients in intensive care unit ( ICU) , and provide a basis for prevention and control of bloodstream infections in critically ill patients. Methods The data of blood cultures of the patients in ICUduring January 2009 to December 2011 was investigated retrospectively.Results In the last 3 years, positive rate of blood cultures of ICU patients was 15. 4% , 15. 7% , and 17. 6% respectively. Among the isolates, Gram-positive bacteria were predominant ( 52. 3% ) , followed in order by gram-negative bacteria ( 33. 1% ) and fungi ( 14. 7% ) . Aerobe and facultative anaerobe were the predominant bacterial isolates ( 99. 7% ) . Enterococcus faeciumand Staphylococcus spp. were the most common gram-positive bacteria, and 4. 5% of E. faecium isolates were resistant to vancomycin. Rate of methicillin-resistance for S. aureus and S. epidermidis was 73. 5% and 93. 7% respectively. In terms of gram-negative bacteria, Acinetobacter calcoaceticus- A. baumannii complex were the leading species, 96. 9% of the isolates had multi-drug resistance and 14. 1% of the isolates had extra-drug resistance. Klebsiella pneumonia and Escherichia coli isolates were less frequently isolated and those producing extended spectrum beta-lactamases accou ted for 70. 3% and 80. 0% of the isolates respectively. Candida spp. was the most common fungi isolates ( 96. 7% )with an annual change of species distribution and declining susceptibility to azoles.Conclusions Gram-positive bacteria should be the major target for prevention and control of bloodstream infections in critically ill patients. Whereas, more attention should be paid to the infection caused by candida spp. and multidrug resistant gram-negative bacteria.
Objective To investigate the characteristics of the pathogens causing bloodstream infection after general surgery in infant and young children patients, and to provide the references for disease treatment and nosocomial infection control. Methods The clinical and laboratory examination data after general surgery in infant and young children patients, who were admitted to our hospital from January 2012 to March 2017, were retrospectively collected. The pathogens and drug resistance were analyzed by SPSS 18.0 software. Results In this study, 109 cases were included, and 117 strains of the pathogens were isolated, including 53 isolates (45.3%) of gram negative bacteria, 41 isolates (35.0%) of gram positive bacteria, and 23 isolates (19.7%) of fungi. Escherichia coli (16/117, 13.7%), Enterococcus faecium (13/117, 11.1%), Candida parapsilosis (12/117, 10.3%), Klebsiella pneumoniae (9/117, 7.7%) and Enterococcus faecalis (8/117, 6.8%) were the top 5 species. Strains producing extended-spectrum beta-lactamase accounted for 87.5% of E. coli (14/16) and 44.4% (4/9) of K. pneumoniae isolates. Both E. faecium and E. faecalis were susceptible to vancomycin. C. parapsilosis showed the susceptibility to the antifungal agents. Conclusion Gram negative bacteria are predominant pathogens causing bloodstream infection after general surgery in infant and young children patients, and infection caused by resistant isolates should be prevented and controlled.
ObjectiveTo analyze the characteristics of distribution and drug resistance of clinical isolated staphylococci in the Whire Union Bacterial Resistance Surveillance Network across Sichuan from 2015 to 2018, so as to provide reference for clinical rational drug use and management of drug-resistant bacteria in Sichuan.MethodsA total of 18 023 strains of staphylococci were isolated from 9 hospitals of Whire Union Bacterial Resistance Surveillance Network for four years (2015-2018). Drug susceptibility test was carried out by disk diffusion method or automated instrument method. The data were statistically analyzed by WHONET 5.6 according to CLSI 2016 standard.ResultsThe 18 023 strains of staphylococci included 10 865 (60.28%) Staphylococcus aureus and 7 158 (39.72%) coagulase negative staphylococci. No strains resistant to vancomycin and linezolid were found. The detection rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci were 25.10% (2 727/ 10 865) and 75.60% (5 411/7 158), respectively. The sensitivity of methicillin-resistant staphylococci to most antibiotics was significantly lower than that of methicillin-sensitive strains (P<0.05). The susceptibility rate of staphylococci to some antibiotics was significantly different from 2015 to 2018(P<0.05). The susceptibility rates of Staphylococcus aureus from different samples to rifampicin, moxifloxacin, ciprofloxacin, levofloxacin, oxacillin and erythromycin were significantly different (P<0.05). The susceptibility rates of Staphylococcus aureus from different departments in different samples of sulfamethoxazole, rifampicin, moxifloxacin, ciprofloxacin, levofloxacin, oxacillin, gentamicin, tetracycline, clindamycin and erythromycin were significantly different (P<0.05).ConclusionsThe susceptibility of strains isolated from different periods, different specimens and departments to the same antimicrobial agents varies greatly. For the infection of staphylococci, we should use drugs under the guidance of drug susceptibility according to the source of samples, which can avoid the abuse of beta-lactam drugs. Strengthening the monitoring and control of drug-resistant bacteria can prevent or reduce the spread of drug-resistant bacteria.
ObjectiveTo analyze the distribution and drug resistance of Enterobacteriaceae in West China Hospital of Sichuan University, to provide long-term monitoring data references for clinical practice.MethodsThe clinical information of non-repetitive Enterobacteriaceae isolates from 2006 to 2015 was collected and analyzed. All the isolates were identified by VITEK-2 Compact Automatic Microbial Identification Analyzer (Bio Merieux, France). The statistic informations were analyzed by WHONET 5.6 and iLabDataforMDR 1.03.ResultsA total of 38 487 strains of Enterobacteriaceae were isolated from 2006 to 2015, mainly including 14 862 stains of Escherichia (38.6%), 12 894 stains of Klebsiella (33.5%), 6 277 stains of Enterobacter (16.3%), 1 758 stains of Proteus (4.6%), 1 257 stains of Serratia (3.3%), 933 stains of Citrobacter (2.4%), and 506 stains of Morganella (1.3%). The top three sample types were sputum (46.9%), urine (18.7%), and secretions (11.5%). The drug resistance rate of Enterobacteriaceae showed a downward trend to most antibacterials. The average resistance rate of Enterobacteriaceae to ampicillin, ampicillin/sulbactam, and cefazolin was 85.3%, 52.6%, and 72.9%, respectively. The resistance rates to ceftriaxone, cefepime, gentamicin, and tobramycin were significantly reduced. The resistance rates to other antibiotics showed decreasing or slow increasing trends. The isolation rate of extended-spectrum β-lactamases (ESBL)-producing strains in Escherichia did not change, but the rate in Klebsiella decreased significantly. The isolation rate of multidrug-resistant organisms (MDRO) showed a slow decrease.ConclusionsThe overall antimicrobial resistance and the isolation rates of MDRO and ESBL-producing organisms showed a downward trend in investigating period. However, the carbapenem-resistant Enterobacteriaceae was rising continuously. Long-term monitoring of drug resistance is of notable value to antibiotic management policies.
ObjectiveTo analyze the diagnostic efficacy of colloidal gold immunochromatography assay (GICA) in detection of SARS-CoV-2.MethodsUsing GICA detection kits from three different manufacturers, 33 serum samples were collected from 12 patients with SARS-CoV-2 infection at different time and 45 serum samples from 45 patients without SARS-CoV-2 infection were collected from West China Hospital of Sichuan University from January to February, 2020.ResultsThe sensitivity, specificity, positive predictive value and negative predictive value of the three GICA reagents were 66.7% - 90.9%, 73.3% - 100.0%, 71.4% - 100.0% and 80.4% - 91.7% respectively. The rates of missed diagnosis and misdiagnosis were 9.1% - 33.3% and 0 - 26.7%, respectively. The positive rate decreased with titer increasing. The interference factors mainly included human immunodeficiency virus infection, high rheumatoid factor blood samples, and hemolysis.ConclusionClinical laboratories should pay attention to the differences in the detection ability and potential cross-reaction of different reagents, or use a combination of multiple antibodies.
Objective To evaluate the clinical effect of minimally invasive aortic valve replacement with Perceval sutureless aortic bioprosthesis in upper ministernotomy or right anterior thoracotomy. MethodsFrom March to November 2022, the patients with simple aortic valve disease were enrolled in the Department of Cardiovascular Surgery of West China Hospital, Sichuan University. After preoperative evaluation, Perceval sutureless bioprosthesis was successfully used to perform aortic valve replacement through the upper ministernotomy or right anterior thoracotomy. The perioperative clinical data and ultrasonic measurement data of all patients were recorded. ResultsA total of 5 patients with simple aortic valve disease were included, including 3 females and 2 males, with a mean age of 71.2 years. Perceval sutureless bioprosthesis was successfully implanted in 5 patients, with a success rate of 100%. There were 3 patients receiving upper ministernotomy and 2 patients receiving right anterior thoracotomy. Two patients underwent ascending aortic plasty at the same time. The mean cardiopulmonary bypass time was 61.0 min, and aortic cross-clamping time was 32.2 min. All patients were discharged successfully without perivalvular leakage, atrioventricular block or stroke. ConclusionThe implantation method of Perceval sutureless bioprosthesis is simple, which can effectively reduce the perioperative risk by shortening the overall operation time, cardiopulmonary bypass time and aortic cross-clamping time. At the same time, its clinical application has promoted the development and popularization of minimally invasive aortic valve replacement, which together with Perceval sutureless bioprosthesis effectively combinates surgical effect and minimally invasive treatment, and has a good clinical application prospect because of its reliable safety and effectiveness.
Objective To analyze the drug resistance of Mycobacterium tuberculosis complex (MTBC) in West China Hospital of Sichuan University in recent years to provide reference for drug resistance monitoring and prevention strategies of tuberculosis in general hospitals. Methods The clinical strains of MTBC that performed drug susceptibility tests in West China Hospital of Sichuan University between January 2019 and December 2022 were collected. The drug susceptibility information of 13 anti-tuberculosis drugs, namely rifampicin, isoniazid, ethambutol, streptomycin, rifabutin, amikacin, kanamycin, ofloxacin, levofloxacin, moxifloxacin, para-aminosalicylic acid, ethionamide, and capreomycin, was collected and retrospectively analyzed. Results A total of 502 clinical strains of MTBC were included, and 366 of them were isolated from newly-treated patients while 136 form re-treated patients. The resistance rates of MTBC strains to the first-line anti-tuberculosis drugs in descending order were 28.69% (isoniazid), 19.72% (ethambutol), and 14.94% (rifampicin). Among the second-line drugs, the resistance rates to ofloxacin, levofloxacin, and moxifloxacin were 13.55%, 12.15%, and 11.95%, respectively. The resistance rates to amikacin, kanamycin, para-aminosalicylic acid, and ethionamide were all less than 10%. The resistance rates to streptomycin, capreomycin, and rifabutin were 17.53%, 13.55%, and 12.15%, respectively. The resistance rates to the remaining 12 anti-tuberculosis drugs except capreomycin of MTBC strains isolated from re-treated patients were higher than those of MTBC strains isolated from newly-treated patients, and the differences were statistically significant (P<0.05). The isolation rates of monodrug-resistant, polydrug-resistant, multidrug-resistant (MDR) and pre-extensively drug-resistant (pre-XDR) strains were 9.36%, 7.37%, 7.17%, and 7.77%, respectively. The isolation rates of strains with the four drug-resistant phenotypes generally showed a downward trend during the four years, and the changing trends were statistically significant (P<0.05). The isolation rates of MDR and pre-XDR strains from re-treated patients were higher than those from newly-treated patients, and the differences were statistically significant (P<0.001). Conclusion Tuberculosis drug resistance in West China Hospital of Sichuan University, which is a comprehensive tuberculosis-designated hospital, remained severe during the four years from 2019 to 2022, and the prevention of tuberculosis and the monitoring of drug resistance should be further strengthened.