1.Improvement of Depression-like Behavior of Depression Model Mice by Sinisan via Regulating GSK-3β/A20/C/EBPβ to Inhibit Activation of Microglia
Hongyun CHEN ; Dongying YANG ; Huiqing LIAO ; Yanyan ZENG ; Linke PAN ; Shasha BAI ; Di DENG ; Yafei SHI ; Rong ZHANG ; Lei YANG
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(12):16-23
		                        		
		                        			
		                        			ObjectiveTo investigate the antidepressant effect of Sinisan (SNS) by regulating glycogen aynthase kinase-3β (GSK-3β)/tumor necrosis factor alpha-induced protein 3(A20)/CCAAT enhancer binding protein β(C/EBPβ) to inhibit the activation of microglia. MethodA total of 72 male C57/6J mice were randomly divided into the normal group, model group, fluoxetine group (5.0 mg·kg-1), low-dose Sinisan group (4.9 g·kg-1), medium-dose Sinisan group (9.8 g·kg-1), and high-dose Sinisan group (19.6 g·kg-1), with 12 mice in each group. After one week of adaptive feeding, chronic unpredictable mild stress (CUMS) was performed to establish the depression model. In the fifth week, drug treatment was conducted for four weeks. In the ninth week, behavioral tests were performed, including sucrose preference test (SPT), open field test (OPT), elevated plus maze (EPM) test, and forced swimming test (FST). Western blot was used to detect the expression levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), nitric oxide synthase (iNOS), GSK-3β, A20, and C/EBPβ in the cortex. The expression of M1-polarized ionized calcium-binding adapter molecule 1 (Iba1) and cluster of differentiation 68 (CD68) in microglia was detected by immunofluorescence. ResultAfter eight weeks of CUMS, compared with the normal group, the mice in the model group had a significantly reduced sucrose preference rate (P<0.01), and the activity in the central area of the OPT was significantly reduced (P<0.01). The activity in the open arm area of the EPM test was significantly reduced (P<0.05), and the immobility time of FST was increased (P<0.01). The expression levels of inflammatory proteins IL-1β, IL-6, and iNOS were increased (P<0.01), and the fluorescence co-localization index of Iba1 and CD68 was increased (P<0.05). The protein expression levels of GSK-3β and C/EBPβ were significantly increased (P<0.05, P<0.01). After four weeks of SNS intervention, compared with the model group, the mice in the SNS group had significantly increased sucrose preference rate (P<0.01), significantly increased activities in the central area and the open arm area in the OPT and the EPM test (P<0.05), and significantly reduced immobility time in the FST (P< 0.01). The protein expression levels of IL-1β, IL-6, and iNOS were significantly decreased (P<0.05), and the fluorescence co-localization index of Iba1 and CD68 was decreased in the high-dose SNS group (P<0.05). The protein expression levels of GSK-3β and C/EBPβ in the medium-dose and high-dose SNS groups were significantly decreased (P<0.01), and that of A20 was significantly increased (P<0.01). ConclusionThe antidepressant effect of SNS is related to the regulation of GSK-3β/A20/C/EBPβ protein expression and the inhibition of M1-type activation of microglia. 
		                        		
		                        		
		                        		
		                        	
2.National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria
Zhiying LIU ; Yunbo CHEN ; Jinru JI ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(1):42-57
		                        		
		                        			
		                        			Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period,9 035 strains of Gram-negative bacteria were collected from 51 hospitals,of which 7 895(87.4%)were Enterobacteriaceae and 1 140(12.6%)were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli( n=4 510,49.9%), Klebsiella pneumoniae( n=2 340,25.9%), Pseudomonas aeruginosa( n=534,5.9%), Acinetobacter baumannii complex( n=405,4.5%)and Enterobacter cloacae( n=327,3.6%). The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus spp. were 47.1%(2 095/4 452),21.0%(427/2 033)and 41.1%(58/141),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(58/4 510)and 13.1%(307/2 340);62.1%(36/58)and 9.8%(30/307)of CREC and CRKP were resistant to ceftazidime/avibactam combination,respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 59.5%(241/405),while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 18.4%(98/534). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions,with statistically significant differences in the prevalence of CRKP and CRPA( χ2=20.489 and 20.252, P<0.001). The prevalence of CREC,CRKP,CRPA,CRAB,ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals( χ2=11.953,81.183,10.404,5.915,12.415 and 6.459, P<0.01 or <0.05),while the prevalence of CRPA was higher in economically developed regions(per capita GDP ≥ 92 059 Yuan)than that in economically less-developed regions(per capita GDP <92 059 Yuan)( χ2=6.240, P=0.012). Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend,and Escherichia coli is ranked in the top,while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different,and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.
		                        		
		                        		
		                        		
		                        	
3.Protective effect of IL-35 mRNA deliveried by lipid nanoparticles against lipopolysaccharide induced acute lung injury in mice
Jierui MAI ; Huisheng SUN ; Yuqin LIAO ; Yanyan LI ; Shumei WANG ; Jing YANG ; Shengqi WANG
Chinese Journal of Pharmacology and Toxicology 2024;38(11):826-833
		                        		
		                        			
		                        			OBJECTIVE To investigate the protective effect of interleukin-35(IL-35)mRNA-lipid nanoparticles(LNP)against lipopolysaccharide(LPS)-induced acute lung injury(ALI)in mice.METHODS Fifity-six mice were randomly divided into 7 groups with 8 mice in each,including the normal control group,IL-35 mRNA-LNP(250 μg·kg-1)group,LPS group,LPS+IL-35 mRNA-LNP(50,125 and 250 μg·kg-1)group and LPS+Dexamethasone(DXM)group.Except for the normal control group and IL-35 mRNA-LNP(250 μg·kg-1)group and ALI model was established by tracheal infusion of LPS in each of the other groups.IL-35 mRNA-LNP(250 μg·kg-1)group and LPS+IL-35 mRNA-LNP(50,125 and 250 μg·kg-1)group were injected with a corresponding dose of LNP encapsulated mRNA complex via the tail vein while the LPS+DXM group was injected with DXM via the tail vein.Lung coefficient and the wet to dry weight ratio(W/D)of lung tissue were recorded.The mRNA levels of inflammatory cytokines tumor necrosis factor-α(TNF-α),Interleukin-6(IL-6)and IL-1βof lung homogenates were detected by real-time fluorescence quantitative PCR(RT-qPCR).LDH activity of lung homogenates and the protein levels of IL-35,TNF-α,IL-6 and IL-1β in lung homogenate were detected by corresponding kits.Hematoxylin-eosin(HE)staining was used to observe and analyze the pathological injury to lung tissue.The expres-sion of Lymphocyte antigen 6G(Ly6G)was detected by Immunofluorescence to reflect the infiltration of neutrophils.RESULTS Compared with the normal control group,LPS group and LPS+DXM group,IL-35 protein expression levels in lung homogenates of the other groups were more significant(P<0.01).Compared with the normal control group,lung coefficient,W/D ratio of lung tissue,LDH activity,mRNA levels and the protein levels of TNF-α,IL-6 and IL-1β in lung homogenates were significantly increased in the LPS group(P<0.01),accompanied by alveolar hemorrhage,alveolar wall thickening and neutro-phils infiltration.After IL-35 mRNA-LNP administration,lung coefficient,W/D ratio of lung tissue,LDH activity,mRNA levels and the protein levels of TNF-α,IL-6 and IL-1β in lung homogenates were signifi-cantly decreased(P<0.01),and alveolar hemorrhage,alveolar wall thickening and neutrophil infiltration were obviously improved.CONCLUSION IL-35 mRNA-LNP can express IL-35 protein in lung tissue of mice,and effectively improve LPS-induced ALI in mice by inhibiting the expression of proinflammatory factors.
		                        		
		                        		
		                        		
		                        	
4.National bloodstream infection bacterial resistance surveillance report(2022): Gram-positive bacteria
Chaoqun YING ; Yunbo CHEN ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(2):99-112
		                        		
		                        			
		                        			Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units,and the top five bacteria were Staphylococcus aureus( n=1 147,36.3%),coagulase-negative Staphylococci( n=928,29.3%), Enterococcus faecalis( n=369,11.7%), Enterococcus faecium( n=296,9.4%)and alpha-hemolyticus Streptococci( n=192,6.1%). The detection rates of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)were 26.4%(303/1 147)and 66.7%(619/928),respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome,rifampin,compound sulfamethoxazole,linezolid,minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%(2/369),and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions( χ2=14.578, P=0.002),while the detection rate of MRCNS in northern China was significantly higher than that in other regions( χ2=15.195, P=0.002). The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals( χ2=13.519 and 12.136, P<0.001). The detection rates of MRSA and MRCNS in economically more advanced regions(per capita GDP≥92 059 Yuan in 2022)were higher than those in economically less advanced regions(per capita GDP<92 059 Yuan)( χ2=9.969 and 7.606, P=0.002和0.006). Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China, Staphylococci is the most common while the MRSA incidence decreases continuously with time;the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China,with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.
		                        		
		                        		
		                        		
		                        	
5.Recommendations for prescription review of commonly used anti-seizure medications in treatment of children with epilepsy
Qianqian QIN ; Qian DING ; Xiaoling LIU ; Heping CAI ; Zebin CHEN ; Lina HAO ; Liang HUANG ; Yuntao JIA ; Lingyan JIAN ; Zhong LI ; Hua LIANG ; Maochang LIU ; Qinghong LU ; Xiaolan MO ; Jing MIAO ; Yanli REN ; Huajun SUN ; Yanyan SUN ; Jing XU ; Meixing YAN ; Li YANG ; Shengnan ZHANG ; Shunguo ZHANG ; Xin ZHAO ; Jie DENG ; Fang FANG ; Li GAO ; Hong HAN ; Shaoping HUANG ; Li JIANG ; Baomin LI ; Jianmin LIANG ; Jianxiang LIAO ; Zhisheng LIU ; Rong LUO ; Jing PENG ; Dan SUN ; Hua WANG ; Ye WU ; Jian YANG ; Yuqin ZHANG ; Jianmin ZHONG ; Shuizhen ZHOU ; Liping ZOU ; Yuwu JIANG ; Xiaoling WANG
Chinese Journal of Applied Clinical Pediatrics 2023;38(10):740-748
		                        		
		                        			
		                        			Anti-seizure medications (ASMs) are the main therapy for epilepsy.There are many kinds of ASMs with complex mechanism of action, so it is difficult for pharmacists to examine prescriptions.This paper put forward some suggestions on the indications, dosage forms/routes of administration, appropriateness of usage and dosage, combined medication and drug interaction, long-term prescription review, individual differences in pathophysiology of children, and drug selection when complicated with common epilepsy, for the reference of doctors and pharmacists.
		                        		
		                        		
		                        		
		                        	
6.Diagnostic and prognostic value of bone marrow biopsy in patients with extranodal NK/T-cell lymphoma based on PET-CT staging
Hao ZHENG ; Yong YANG ; Yanyan QIU ; Siqin LIAO ; Cheng HUANG ; Guiqing SHI ; Ruizhi ZHAO ; Tianlan TANG ; Shunyuan WANG ; Silin CHEN ; Tingbo LIU ; Benhua XU
Chinese Journal of Radiation Oncology 2023;32(4):313-318
		                        		
		                        			
		                        			Objective:To analyze the diagnostic and prognostic value of routine bone marrow examination in patients with extranodal NK/T-cell lymphoma (ENKTCL) based on PET-CT staging.Methods:Clinical data of 186 patients who received bone marrow biopsy and bone marrow aspiration in Fujian Medical University Union Hospital from 2013 to 2021 were retrospectively analyzed. All patients were divided into bone marrow biopsy + bone marrow aspiration group ( n=186) and PET-CT + bone marrow biopsy group ( n=139). The sensitivity, specificity, positive and negative predictive values were compared between two groups. The data were analyzed and plotted. Survival analysis was performed using Kaplan-Meier method and log-rank test. Results:In the whole cohort, 45 patients were positive for bone marrow biopsy, and 30 of them were positive for bone marrow aspiration. A total of 141 patients who were negative for bone marrow biopsy also achieved negative results for bone marrow aspiration. A total of 139 patients completed PET-CT staging and bone marrow biopsy. And 30 patients were diagnosed with positive bone marrow by PET-CT, in which 22 of them were confirmed positive by bone marrow biopsy. Among 109 patients diagnosed with negative bone marrow by PET-CT, 5 of them were confirmed positive by bone marrow biopsy. All these cases were classified as stage Ⅳ due to distant metastases. PET-CT had a diagnostic sensitivity of 81.5%, a specificity of 92.9%, a positive predictive value of 73.3%, and a negative predictive value of 95.4%. Among early stage (Ⅰ-Ⅱ stage) patients diagnosed with PET-CT, all of them were negative for bone marrow biopsy (the negative predictive value was 100%). In stage Ⅳ patients ( n=55), the 1-year overall survival of patients with bone marrow involvement by bone marrow biopsy or PET-CT ( n=35) compared with their counterparts with the involvement of other organs ( n=20) was 28.7% vs.42.0% ( P=0.13), and 1-year progression free survival rates was 23.2% vs. 23.3% in ( P=0.94). Conclusions:Routine bone marrow biopsy does not change the original staging of patients with early stage ENKTCL based on PET-CT staging. Advanced stage patients with positive bone marrow biopsy tend to obtain worse prognosis, indicating that bone marrow biopsy still has certain value.
		                        		
		                        		
		                        		
		                        	
7.Development, reliability and validity of the Sexual Health Education Needs Assessment Scale for Breast Cancer Patients
Ping ZHU ; Xiuxiu YANG ; Meixiang WANG ; Fang CHENG ; Yi PEI ; Lingyun SHI ; Xinxin LIU ; Yanyan LIAO ; Wenbo ZHU ; Liuliu ZHANG
Chinese Journal of Modern Nursing 2023;29(28):3815-3822
		                        		
		                        			
		                        			Objective:To develop the Sexual Health Education Needs Assessment Scale for Breast Cancer Patients and test its reliability and validity.Methods:Guided by Maslow's hierarchy of needs theory and knowledge, belief, and practice theory, an initial scale was formed through literature review, semi-structured interviews and Delphi expert consultation. Through cognitive interviews with 9 patients, the scale was further revised and improved to form a clinical trial version. From December 2021 to September 2022, 397 breast cancer patients from 9 ClassⅢ hospitals in 6 provinces, municipalities and autonomous regions were selected by convenience sampling to conduct a questionnaire survey, test the reliability and validity of the scale and grade it.Results:The Sexual Health Education Needs Assessment Scale for Breast Cancer Patients included four dimensions and 32 items in total. Exploratory factor analysis extracted a total of four common factors, with a cumulative variance contribution rate of 72.258%. The content validity index of the scale was 0.865, and the content validity index of each item was 0.929 to 1.000. The correlation coefficients between each dimension of the scale and the total scale were 0.789 to 0.956, and the correlation coefficients between dimensions were 0.635 to 0.863. The Cronbach's α coefficient of the total scale was 0.979, and the Cronbach's α coefficients of each dimension were 0.897 to 0.969. The half reliability of the total scale was 0.941, and the half reliability of each dimension was 0.851 to 0.946. The total score of the scale was 32 to 160, with 32 to 77 being at a low level, 78 to 117 being at a medium level, and 118 to 160 being at a high level.Conclusions:The developed Sexual Health Education Needs Assessment Scale for Breast Cancer Patients has good reliability and validity, and is suitable for breast cancer patients' sexual health education needs assessment.
		                        		
		                        		
		                        		
		                        	
8.Rapid screening of single guide RNA targeting pig genome and the harvesting of monoclonal cells by microarray seal.
Mengyu GAO ; Xinglong ZHU ; Shisheng WANG ; Bingqi ZHANG ; Yunlin ZHANG ; Yuting HE ; Yanyan ZHOU ; Shun LI ; Guang YANG ; Guangneng LIAO ; Ji BAO ; Hong BU
Journal of Biomedical Engineering 2021;38(1):111-121
		                        		
		                        			
		                        			The emergence of regular short repetitive palindromic sequence clusters (CRISPR) and CRISPR- associated proteins 9 (Cas9) gene editing technology has greatly promoted the wide application of genetically modified pigs. Efficient single guide RNA (sgRNA) is the key to the success of gene editing using CRISPR/Cas9 technology. For large animals with a long reproductive cycle, such as pigs, it is necessary to screen out efficient sgRNA
		                        		
		                        		
		                        		
		                        			Animals
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		                        			CRISPR-Cas Systems/genetics*
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		                        			Clustered Regularly Interspaced Short Palindromic Repeats/genetics*
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		                        			Gene Editing
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		                        			RNA, Guide/genetics*
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		                        			Swine
		                        			
		                        		
		                        	
9.Construction of sensitive indicators of breast nursing quality
Lili WANG ; Bei WANG ; Yan WU ; Yanyan LIAO ; Kaihui WANG ; Yanming DU ; Jun PAN
Chinese Journal of Practical Nursing 2019;35(2):86-91
		                        		
		                        			
		                        			Objective To construct sensitive, scientific and practical breast nursing quality evaluation indicators, and provide evidence for hospital breast nursing quality evaluation and monitoring. Methods Potential sensitive indicators of nursing quality were initially built by referencing the development process of the nursing quality indicators national database system of United States, by retrieving the domestic and foreign documents, by combining with breast cancer diagnosis and treatment guidelines, nursing textbooks, and nursing negative events, by clinical investigation and group discussion. An expert survey paper was prepared and three rounds surveys were conducted to revise and fix the sensitive indicators of breast nursing quality. Results The positive coefficients of the three rounds of expert consultation were 100% , the authoritative coefficients of the three rounds were 0.847,0.851,0.849, respectively. The coordination coefficient of the three rounds of experts was 0.371-0.476、0.597-0.736、0.739-0.873, P<0.01, and finally 4 sensitive indicators of breast specialist care quality were established. Conclusions The nursing quality sensitive indicators were constructed by Delphi method. They comply with the principles of scientificity and rigorousness, and have the characteristics of breast nursing. They can be verified by clinical practices in the role of nursing quality control and evaluation, and gradually achieve effective data sharing to clinical guidelines to help the development of specialist care.
		                        		
		                        		
		                        		
		                        	
10.Construction and characterization of △sseK2 mutant strain of Salmonella typhimurium SL1344
Xiaojie ZHANG ; Chunjie ZHANG ; Xiangchao CHENG ; Yinju LI ; Yadong YANG ; Chuan YU ; Cheng-Shui LIAO ; Yanyan JIA ; DuFuyu
Chinese Journal of Microbiology and Immunology 2019;39(4):256-263
		                        		
		                        			
		                        			Objective To analyze the biological characteristics of a mutant strain of Salmonella ty-phimurium SL1344 with sseK2-deletion (SL1344△sseK2) in order to provide reference for further study of safe and effective live vaccines. Methods The mutant strain SL1344△sseK2 with a deletion of 1047 bp in sseK2 gene was constructed through a two-step allelic exchange using recombinant suicide plasmid. Its com-plemented strain, SL1344C△sseK2, was also constructed. Biological and immunological characteristics of the mutant strain were detected. Results PCR, double-enzyme digestion and sequencing analysis showed that the mutant strain SL1344△sseK2 and the complemented strain SL1344C△sseK2 were successfully con-structed. The serotype of the mutant strain was 1,4,[5],12:i:1,2, identical to the parent strain SL1344. In addition, the mutant strain showed no significant change in biochemical characteristics or growth rate and was genetically stable in vitro. Compared with the parent strain SL1344, the virulence of SL1344△sseK2 was attenuated in BALB/ c mice. The median lethal dose of SL1344△sseK2 for 6-week-old BALB/ c mice was 3. 44×108 colony-forming units (CFU), which was 1620 times lower than that of SL1344. Oral immuniza-tion with SL1344△sseK2 protected 62. 5% of the mice against challenge with wild Salmonella typhimurium strains on 17 d after vaccination. The levels of serum IgG antibody peaked on 14 d after immunization. No significant difference in biological characteristics was observed between the complemented and the parent strains, indicating that the mutant strain was basically complemented to the wild-type strain.Conclusions The mutant strain SL1344△sseK2 was constructed successfully and genetically stable with sig-nificantly attenuated virulence and good immunogenicity. This study suggested that sseK2 gene played an im-portant role in regulating the virulence of SL1344, which might provide reference for further study of its func-tion and for assessing its potential as a candidate live attenuated vaccine.
		                        		
		                        		
		                        		
		                        	
            
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