1.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
2.Comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery
Wei GAO ; Xiaoxi LIN ; Yun ZOU ; Yajing QIU ; Hui CHEN ; Li HU ; Lei CHANG ; Yunbo JIN ; Chen HUA
Chinese Journal of Plastic Surgery 2024;40(3):286-292
Objective:To explore the clinical outcome and applicability of the comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery.Methods:The clinical data of patients who underwent plastic aesthetic and reconstructive surgery with the comb flap technique in Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2018 to December 2022 were retrospectively analyzed. The application of the comb flap technique follows the concept of stepwise design, that was, preoperative and intraoperative design and adjustment were carried out step by step and in sequence, and the design was combined with the surgical procedure. Its main operations included: an incision was designed along the edge of the target area, the tissue flap was widely separated at the base of the target area. The tissue flap was cut in sequence perpendicular to the cutting edge and temporarily sutured and fixed, the edge was cut and fixed. During the operation, the tension of the incision and the local appearance could be adjusted. The incisal edge was finely sutured, and the temporary suture was finally removed. The healing of surgical incision and complications were observed after the operation, and the facial recovery and surgical effect were followed up.Results:Six patients were enrolled, including 3 males and 3 females, aged from 2 to 58 years. One patient underwent upper eyelid tightening and lower eyelid blepharoplasty through subeyebrow incision. One patient underwent middle and lower face rhytidectomy. One patient underwent thick lip thinning and right facial liposuction. One patient underwent facial congenital melanocytic nevi resection. One patient underwent eyebrow congenital melanocytic nevus resection. One patient underwent facial flap repair. All patients had primary healing of incision, and no surgery-related complications occurred. All patients were followed up for 3 to 18 months, and all patients were satisfied with the surgical effect.Conclusion:The application of comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery can delicately adjust the alignment of the incision margin, make the tension evenly distributed, and reduce the risk of scar formation and deformity after the operation. It has a wide range of clinical applications and good applicability.
3.Comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery
Wei GAO ; Xiaoxi LIN ; Yun ZOU ; Yajing QIU ; Hui CHEN ; Li HU ; Lei CHANG ; Yunbo JIN ; Chen HUA
Chinese Journal of Plastic Surgery 2024;40(3):286-292
Objective:To explore the clinical outcome and applicability of the comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery.Methods:The clinical data of patients who underwent plastic aesthetic and reconstructive surgery with the comb flap technique in Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2018 to December 2022 were retrospectively analyzed. The application of the comb flap technique follows the concept of stepwise design, that was, preoperative and intraoperative design and adjustment were carried out step by step and in sequence, and the design was combined with the surgical procedure. Its main operations included: an incision was designed along the edge of the target area, the tissue flap was widely separated at the base of the target area. The tissue flap was cut in sequence perpendicular to the cutting edge and temporarily sutured and fixed, the edge was cut and fixed. During the operation, the tension of the incision and the local appearance could be adjusted. The incisal edge was finely sutured, and the temporary suture was finally removed. The healing of surgical incision and complications were observed after the operation, and the facial recovery and surgical effect were followed up.Results:Six patients were enrolled, including 3 males and 3 females, aged from 2 to 58 years. One patient underwent upper eyelid tightening and lower eyelid blepharoplasty through subeyebrow incision. One patient underwent middle and lower face rhytidectomy. One patient underwent thick lip thinning and right facial liposuction. One patient underwent facial congenital melanocytic nevi resection. One patient underwent eyebrow congenital melanocytic nevus resection. One patient underwent facial flap repair. All patients had primary healing of incision, and no surgery-related complications occurred. All patients were followed up for 3 to 18 months, and all patients were satisfied with the surgical effect.Conclusion:The application of comb flap technique and stepwise design concept in plastic aesthetic and reconstructive surgery can delicately adjust the alignment of the incision margin, make the tension evenly distributed, and reduce the risk of scar formation and deformity after the operation. It has a wide range of clinical applications and good applicability.
4.Effects of Xinyue Capsules on the expression of glycerophospholipid metabolizing enzymes in a rat model of cardiac hypertrophy
Hao ZHANG ; Xiao-Yun DING ; Hu WANG ; Ting-Ting LI ; Yu-Mei QIU ; Meng-Die XIE ; Wei DONG ; Yi-Xin SHEN ; Xi-Lan TANG
Chinese Traditional Patent Medicine 2024;46(11):3594-3602
AIM To investigate the effects of Xinyue Capsules on the expression of glycerophospholipid metabolizing enzymes in isoproterenol(ISO)-induced rat heart tissue and primary myocardial cells of neonatal rats.METHODS The SD rats were randomly divided into the normal group,the model group,the Xinyue Capsules intervention group and Xinyue Capsules control group,with 8 rats in each group.The rat model of cardiac hypertrophy was established by 14 days consecutive intraperitoneal injection of ISO(30 mg/kg).Prior to the modeling,once daily administration of 0.393 g/kg Xinyue Capsules was given by gavage from 3 days in advance to the end of the experiment.After the last administration,the procurement of blood from abdominal aorta,the left and right ventricles were processed.And the rats had their indices levels of the heart,the left ventricle and the right ventricle measured;their pathomorphological changes of myocardial tissue observed using HE staining;their expressions of cardiac hypertrophy-related myocardial embryonic genes ANP,β-MHC and α-SKA mRNA detected using RT-qPCR method;and their serum TC,TG,LDL-C and HDL-C levels detected by biochemical method.In in vitro experiment,the neonatal rat model of myocardial hypertrophy was induced by exposure to ISO 1 μmol/L for 24 h.The investigation of the effect of Xinyue Capsules 12.5 μg/mL on ISO-induced myocardial hypertrophy was conducted by detection of myocardial cell area,embryo genes related to cardiac hypertrophy and myocardial cells protein cuntent.The further anti-cardiac hypertrophy mechanism of Xinyue Capsules research was conducted using RT-qPCR and Western blot to detect the gene and protein expressions of phospholipase A2(PLA2G6),phospholipase A1 member A(PLA1A)and lecithin cholesterol acyltransferase(LCAT)in left ventricle tissue and myocardial cells of each group.RESULTS The in vivo experimental result showed that compared with the normal group,the model group displayed increased indices levels of the heart,the left ventricle and the right ventricle and cross-sectional area of left ventricular myocytes(P<0.05);and up-regulated expressions of ANP,β-MHC,α-SKA mRNA and PLA2G6,PLA1A and LCAT mRNA and proteins in the left ventricle(P<0.05);and increased levels of serum TC,TG and LDL-C(P<0.05);and decreased HDL-C level(P<0.05).However,the intervention of Xinyue Capsules inhibited the changes of the aforementioned indices(P<0.05).The in vitro experimental result revealed that Xinyue Capsules inhibited the ISO-induced increases of myocardial cell surface area and myocardial cell protein level,the up-regulation of ANP,β-MHC,α-SKA mRNA expressions and the PLA2G6,PLA1A,LCAT mRNA and protein expressions as well(P<0.05).CONCLUSION Xinyue Capsules can improve the ISO-induced cardiac hypertrophy in rats,and its mechanism may be associated with its regulation upon the expressions of glycerophospholipid metabolism-related enzymes PLA2G6,PLA1A and LCAT.
5.Drug resistance and molecular typing of diarrheagenic escherichia coli from the diarrhea clinics in Qingpu District, Shanghai.
Yi Ru SHI ; Xi YU ; Yi HU ; Shu Wen MA ; Xiao Yun LU ; Xi GONG ; Qiu Fang XU
Chinese Journal of Preventive Medicine 2023;57():65-71
Objective: To analyze the drug resistance and multilocus sequence typing of five types of diarrheagenic Escherichia coli (DEC) isolated from diarrhea outpatients of diarrhea comprehensive monitoring designated hospital in Qingpu District, Shanghai from 2015 to 2019. Methods: From January 2015 to December 2019, five types of DEC, isolated and identified from diarrhea outpatient cases' anal swabs of the Qingpu branch of Zhongshan Hospital were collected to determine the minimal inhibitory concentration by using the micro broth dilution susceptibility test. The strains, resistant to the third-generation cephalosporins or carbapenems, or producing ESBLs, were selected based on the results of sensitivity tests and determined by WGS. The MLST typing of DEC was analyzed based on the WGS technology and the minimum spanning tree was constructed by BioNumerics 7.6 software to analyze the local dominant flora. Results: A total of 513 strains of DEC were detected and isolated from 4 494 anal swabs, with a detection rate of 11.42%. About 500 strains were tested for drug sensitivity to nine antibiotics in four classes, including 330 strains of enterotoxigenic E.coli (ETEC), 72 strains of enteroaggregative E.coli (EAEC), 95 strains of enteropathogenic E.coli (EPEC), 1 strain of enterohemorrhagic E.coli (EHEC), and 2 strains of enteroinvasive E.coli (EIEC). From 2015 to 2019, the resistance rate of cefotaxime-clavulanic acid was significantly different (P<0.05). The resistance rate of virulence types of DEC to nalixic acid was significantly different (P<0.05). About 71 strains of DEC were determined by WGS, and 77 drug-resistant genes were detected. Strains were classified into 32 ST subtypes, with the dominant genotypes being ST-1491 (29.6%, 21/71) and ST-10 Complex (23.9%, 17/71). All ST-1491 produced ESBLs, which were blaCTX-M gene mutant strains. The dominant type of ST-10 complex was ST-218 (35.3%, 6/17). In addition, 8 strains of EAEC, 14 strains of EPEC and 49 strains of ETEC were classified into 7, 14 and 18 ST subtypes, respectively. Conclusion: The drug resistance of DEC strains from the diarrhea outpatient case of Qingpu District is serious. The ST types of EAEC and EPEC are highly polymorphic. The dominant ST types of DEC are basically consistent with the common genotypes in southeast China.
6.Status of fungal sepsis among preterm infants in 25 neonatal intensive care units of tertiary hospitals in China.
Xin Cheng CAO ; Si Yuan JIANG ; Shu Juan LI ; Jun Yan HAN ; Qi ZHOU ; Meng Meng LI ; Rui Miao BAI ; Shi Wen XIA ; Zu Ming YANG ; Jian Fang GE ; Bao Quan ZHANG ; Chuan Zhong YANG ; Jing YUAN ; Dan Dan PAN ; Jing Yun SHI ; Xue Feng HU ; Zhen Lang LIN ; Yang WANG ; Li Chun ZENG ; Yan Ping ZHU ; Qiu Fang WEI ; Yan GUO ; Ling CHEN ; Cui Qing LIU ; Shan Yu JIANG ; Xiao Ying LI ; Hui Qing SUN ; Yu Jie QI ; Ming Yan HEI ; Yun CAO
Chinese Journal of Pediatrics 2023;61(1):29-35
Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34+0 weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.
Infant
;
Infant, Newborn
;
Humans
;
Birth Weight
;
Intensive Care Units, Neonatal
;
Retrospective Studies
;
Tertiary Care Centers
;
Infant, Extremely Low Birth Weight
;
Gestational Age
;
Infant, Extremely Premature
;
Sepsis/epidemiology*
;
Retinopathy of Prematurity/epidemiology*
;
Bronchopulmonary Dysplasia/epidemiology*
7.Single-dose AAV-based vaccine induces a high level of neutralizing antibodies against SARS-CoV-2 in rhesus macaques.
Dali TONG ; Mei ZHANG ; Yunru YANG ; Han XIA ; Haiyang TONG ; Huajun ZHANG ; Weihong ZENG ; Muziying LIU ; Yan WU ; Huan MA ; Xue HU ; Weiyong LIU ; Yuan CAI ; Yanfeng YAO ; Yichuan YAO ; Kunpeng LIU ; Shifang SHAN ; Yajuan LI ; Ge GAO ; Weiwei GUO ; Yun PENG ; Shaohong CHEN ; Juhong RAO ; Jiaxuan ZHAO ; Juan MIN ; Qingjun ZHU ; Yanmin ZHENG ; Lianxin LIU ; Chao SHAN ; Kai ZHONG ; Zilong QIU ; Tengchuan JIN ; Sandra CHIU ; Zhiming YUAN ; Tian XUE
Protein & Cell 2023;14(1):69-73
8.To compare the efficacy and incidence of severe hematological adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia.
Xiao Shuai ZHANG ; Bing Cheng LIU ; Xin DU ; Yan Li ZHANG ; Na XU ; Xiao Li LIU ; Wei Ming LI ; Hai LIN ; Rong LIANG ; Chun Yan CHEN ; Jian HUANG ; Yun Fan YANG ; Huan Ling ZHU ; Ling PAN ; Xiao Dong WANG ; Gui Hui LI ; Zhuo Gang LIU ; Yan Qing ZHANG ; Zhen Fang LIU ; Jian Da HU ; Chun Shui LIU ; Fei LI ; Wei YANG ; Li MENG ; Yan Qiu HAN ; Li E LIN ; Zhen Yu ZHAO ; Chuan Qing TU ; Cai Feng ZHENG ; Yan Liang BAI ; Ze Ping ZHOU ; Su Ning CHEN ; Hui Ying QIU ; Li Jie YANG ; Xiu Li SUN ; Hui SUN ; Li ZHOU ; Ze Lin LIU ; Dan Yu WANG ; Jian Xin GUO ; Li Ping PANG ; Qing Shu ZENG ; Xiao Hui SUO ; Wei Hua ZHANG ; Yuan Jun ZHENG ; Qian JIANG
Chinese Journal of Hematology 2023;44(9):728-736
Objective: To analyze and compare therapy responses, outcomes, and incidence of severe hematologic adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia (CML) . Methods: Data of patients with chronic phase CML diagnosed between January 2006 and November 2022 from 76 centers, aged ≥18 years, and received initial flumatinib or imatinib therapy within 6 months after diagnosis in China were retrospectively interrogated. Propensity score matching (PSM) analysis was performed to reduce the bias of the initial TKI selection, and the therapy responses and outcomes of patients receiving initial flumatinib or imatinib therapy were compared. Results: A total of 4 833 adult patients with CML receiving initial imatinib (n=4 380) or flumatinib (n=453) therapy were included in the study. In the imatinib cohort, the median follow-up time was 54 [interquartile range (IQR), 31-85] months, and the 7-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.2%, 88.4%, 78.3%, and 63.0%, respectively. The 7-year FFS, PFS, and OS rates were 71.8%, 93.0%, and 96.9%, respectively. With the median follow-up of 18 (IQR, 13-25) months in the flumatinib cohort, the 2-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.4%, 86.5%, 58.4%, and 46.6%, respectively. The 2-year FFS, PFS, and OS rates were 80.1%, 95.0%, and 99.5%, respectively. The PSM analysis indicated that patients receiving initial flumatinib therapy had significantly higher cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) and higher probabilities of FFS than those receiving the initial imatinib therapy (all P<0.001), whereas the PFS (P=0.230) and OS (P=0.268) were comparable between the two cohorts. The incidence of severe hematologic adverse events (grade≥Ⅲ) was comparable in the two cohorts. Conclusion: Patients receiving initial flumatinib therapy had higher cumulative incidences of therapy responses and higher probability of FFS than those receiving initial imatinib therapy, whereas the incidence of severe hematologic adverse events was comparable between the two cohorts.
Adult
;
Humans
;
Adolescent
;
Imatinib Mesylate/adverse effects*
;
Incidence
;
Antineoplastic Agents/adverse effects*
;
Retrospective Studies
;
Pyrimidines/adverse effects*
;
Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy*
;
Treatment Outcome
;
Benzamides/adverse effects*
;
Leukemia, Myeloid, Chronic-Phase/drug therapy*
;
Aminopyridines/therapeutic use*
;
Protein Kinase Inhibitors/therapeutic use*
9.Drug resistance and molecular typing of diarrheagenic escherichia coli from the diarrhea clinics in Qingpu District, Shanghai City from 2015 to 2019.
Yi Ru SHI ; Xi YU ; Yi HU ; Shu Wen MA ; Xiao Yun LU ; Xi GONG ; Qiu Fang XU
Chinese Journal of Preventive Medicine 2023;57(8):1199-1205
Objective: To analyze the drug resistance and multilocus sequence typing of five types of diarrheagenic Escherichia coli (DEC) isolated from diarrhea outpatients of diarrhea comprehensive monitoring designated hospital in Qingpu District, Shanghai City from 2015 to 2019. Methods: From January 2015 to December 2019, five types of DEC, isolated and identified from diarrhea outpatient cases' anal swabs of the Qingpu branch of Zhongshan Hospital were collected to determine the minimal inhibitory concentration by using the micro broth dilution susceptibility test. The strains, resistant to the third-generation cephalosporins or carbapenems, or producing ESBLs, were selected based on the results of sensitivity tests and determined by WGS. The MLST typing of DEC was analyzed based on the WGS technology and the minimum spanning tree was constructed by BioNumerics 7.6 software to analyze the local dominant flora. Results: A total of 513 strains of DEC were detected and isolated from 4 494 anal swabs, with a detection rate of 11.42%. About 500 strains were tested for drug sensitivity to nine antibiotics in four classes, including 330 strains of enterotoxigenic E.coli (ETEC), 72 strains of enteroaggregative E.coli (EAEC), 95 strains of enteropathogenic E.coli (EPEC), 1 strain of enterohemorrhagic E.coli (EHEC), and 2 strains of enteroinvasive E.coli (EIEC). From 2015 to 2019, the resistance rate of cefotaxime-clavulanic acid was significantly different (P<0.05). The resistance rate of virulence types of DEC to nalixic acid was significantly different (P<0.05). About 71 strains of DEC were determined by WGS, and 77 drug-resistant genes were detected. Strains were classified into 32 ST subtypes, with the dominant genotypes being ST-1491 (29.6%, 21/71) and ST-10 Complex (23.9%, 17/71). All ST-1491 produced ESBLs, which were blaCTX-M gene mutant strains. The dominant type of ST-10 complex was ST-218 (35.3%, 6/17). In addition, 8 strains of EAEC, 14 strains of EPEC and 49 strains of ETEC were classified into 7, 14 and 18 ST subtypes, respectively. Conclusion: The drug resistance of DEC strains from the diarrhea outpatient case of Qingpu District is serious. The ST types of EAEC and EPEC are highly polymorphic. The dominant ST types of DEC are basically consistent with the common genotypes in southeast China.
10.Drug resistance and molecular typing of diarrheagenic escherichia coli from the diarrhea clinics in Qingpu District, Shanghai City from 2015 to 2019.
Yi Ru SHI ; Xi YU ; Yi HU ; Shu Wen MA ; Xiao Yun LU ; Xi GONG ; Qiu Fang XU
Chinese Journal of Preventive Medicine 2023;57(8):1199-1205
Objective: To analyze the drug resistance and multilocus sequence typing of five types of diarrheagenic Escherichia coli (DEC) isolated from diarrhea outpatients of diarrhea comprehensive monitoring designated hospital in Qingpu District, Shanghai City from 2015 to 2019. Methods: From January 2015 to December 2019, five types of DEC, isolated and identified from diarrhea outpatient cases' anal swabs of the Qingpu branch of Zhongshan Hospital were collected to determine the minimal inhibitory concentration by using the micro broth dilution susceptibility test. The strains, resistant to the third-generation cephalosporins or carbapenems, or producing ESBLs, were selected based on the results of sensitivity tests and determined by WGS. The MLST typing of DEC was analyzed based on the WGS technology and the minimum spanning tree was constructed by BioNumerics 7.6 software to analyze the local dominant flora. Results: A total of 513 strains of DEC were detected and isolated from 4 494 anal swabs, with a detection rate of 11.42%. About 500 strains were tested for drug sensitivity to nine antibiotics in four classes, including 330 strains of enterotoxigenic E.coli (ETEC), 72 strains of enteroaggregative E.coli (EAEC), 95 strains of enteropathogenic E.coli (EPEC), 1 strain of enterohemorrhagic E.coli (EHEC), and 2 strains of enteroinvasive E.coli (EIEC). From 2015 to 2019, the resistance rate of cefotaxime-clavulanic acid was significantly different (P<0.05). The resistance rate of virulence types of DEC to nalixic acid was significantly different (P<0.05). About 71 strains of DEC were determined by WGS, and 77 drug-resistant genes were detected. Strains were classified into 32 ST subtypes, with the dominant genotypes being ST-1491 (29.6%, 21/71) and ST-10 Complex (23.9%, 17/71). All ST-1491 produced ESBLs, which were blaCTX-M gene mutant strains. The dominant type of ST-10 complex was ST-218 (35.3%, 6/17). In addition, 8 strains of EAEC, 14 strains of EPEC and 49 strains of ETEC were classified into 7, 14 and 18 ST subtypes, respectively. Conclusion: The drug resistance of DEC strains from the diarrhea outpatient case of Qingpu District is serious. The ST types of EAEC and EPEC are highly polymorphic. The dominant ST types of DEC are basically consistent with the common genotypes in southeast China.

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