Objective To assess the value of nuchal translu-cency in combination with non-invasive prenatal DNA test in fetal with chromosomal disease. Methods A total of 713 cases with single pregnancies, with 11 ~ 14 gestational weeks, were enrolled in this study. We measured the thickness of nuchal translu-cency, If the thickness was abnomal, the pregnant women would receive the non-invasive prenatal DNA test on voluntary basis and were followed up. Results There were 27 cases with abnormal NT among 713 cases. Twenty-one cases received non-invasive prenatal DNA test , the test results showed that 3 cases were trisomy 21 , 1 cases was trisomy 18. Among the 17 cases with normal chromosome karyotype, 6 cases were found abnomal during the follw-up. Two cases were found abnomal among the 6 cases undergo the non-invasive prenatal DNA test.The thickness of NT, ranging from 3.7 mm to 4.4 mm, was trisomy 21, with the average of 4.0 mm, and the thickness of NT was 5.0mm and was trisomy 18. Conclusions The application of nuchal translu-cency in combination with non-invasive prenatal DNA test could improve the ability to find fetal chromosomal disease and to decrease the birth defect.

Objective To investigate the effect and mechanism of sodium cantharidate on the proliferation,migration and invasion of esophageal carcinoma EC9706 cells.Methods Esophageal cancer EC9706 cells were randomly divided into blank control group,low-dose sodium cantharidate group,medium-dose sodium cantharidate group,high-dose sodium canthari-date group and cisplatin group.The EC9706 cells in the low-,medium-and high-dose sodium cantharidate groups were given fi-nal mass concentration of 1.0,2.5 and 5.0 mg·L-1 sodium cantharidate intervention,respectively.The EC9706 cells in the cisplatin group were treated with the final mass concentration of 140 mg·L-1 cisplatin,and the cells in the control group was cultured in Dulbecco's modified Eagle's medium.The cell proliferation rate in each group was detected by cell counting reagent-8 method,the mobility of EC9706 cells in each group was detected by scratch test,the invasion rate of EC9706 cells in each group was detected by Transwell method,and the levels of Wnt3a and β-catenin mRNA in EC9706 cells in each group were detected by real-time quantitative polymerase chain reaction method,and the levels of Wnt3a and β-catenin protein in EC9706 cells in each group were detected by Western blot.Results At 24,48 and 72 h of cultivation,the proliferation rate of EC9706 cells in the low-dose sodium cantharidate group,medium-dose sodium cantharidate group,high-dose sodium canthari-date group and cisplatin group was significantly lower than that in the blank control group(P＜0.05);the proliferation rate of EC9706 cells in the low-dose sodium cantharidate group and medium-dose of sodium cantharidate group was significantly higher than that in the high-dose sodium cantharidate group and cisplatin group(P＜0.05);the proliferation rate of EC9706 cells in the low-dose sodium cantharidate group was significantly higher than that in the medium-dose sodium cantharidate group(P＜0.05);there was no significant difference in the proliferation rate of EC9706 cells between the high-dose sodium cantharidate group and cisplatin group(P＞0.05);the proliferation rate of EC9706 cells in the low-dose sodium cantharidate group,medium-dose sodium cantharidate group,high-dose sodium cantharidate group and cisplatin group was significantly decreased with the extension of culture time(P＜0.05).The mobility rate and invasion rate of EC9706 cells in the low-dose sodium cantharidate group,medium-dose sodium cantharidate group,high-dose sodium cantharidate group and cisplatin group were significantly lower than those in the blank control group(P＜0.05);the mobility rate and invasion rate of EC9706 cells in the low-dose sodium cantharidate group and medium-dose sodium cantharidate group were significantly higher than those in the high-dose sodium cantharidate group and cisplatin group(P＜0.05);the migration rate and invasion rate of EC9706 cells in the low-dose sodium cantharidate group were significantly higher than those in the medium-dose sodium cantharidate group(P＜0.05);there was no significant difference in the mobility rate and invasion rate of EC9706 cells between the high-dose sodium cantharidate group and cisplatin group(P＞0.05).The relative expression levels of Wnt3a and β-catenin mRNA and protein in EC9706 cells in the low-dose sodium cantharidate group,medium-dose sodium cantharidate group,high-dose sodium cantharidate group and cisplatin group were significantly lower than those in the blank control group(P＜0.05);the relative expression levels of Wnt3a and β-catenin mRNA and protein in EC9706 cells in the low-dose sodium cantharidate group and medium-dose sodium cantharidate group were significantly higher than those in the high-dose sodium cantharidate group and cisplatin group(P＜0.05);the relative expressions levels of Wnt3a and β-catenin mRNA and protein in EC9706 cells in the low-dose sodium cantharidate group were significantly higher than those in the medium-dose sodium cantharidate group(P＜0.05);there was no significant difference in the relative expression levels of Wnt3a and β-catenin mRNA and protein in EC9706 cells between the high-dose sodium cantharidate group and cisplatin group(P＞0.05).Conclusion Sodium cantharidate can significantly inhibit the proliferation,migration and invasion of esophageal carcinoma EC9706 cells,and its mechanism may be related to the inhibition of the Wnt3a/β-catenin pathway.

OBJECTIVETo elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China.

METHODSA total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing.

RESULTSAmong 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions.

CONCLUSIONThe results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Animals ; Anti-Bacterial Agents ; pharmacology ; Cefotaxime ; pharmacology ; Chickens ; microbiology ; China ; Ciprofloxacin ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Food Contamination ; Food Microbiology ; Meat ; microbiology ; Salmonella ; classification ; isolation & purification ; Serotyping ; beta-Lactamases

Objective:To investigate the serotypes and antimicrobial resistance of seven invasive non-typhoidal Salmonella (iNTS) isolates. Methods:For 7 iNTS strains collected, serotype identification, antimicrobial susceptibility testing and whole genome sequencing were performed. We identified, annotated and analyzed the serotypes, MLST types, and antimicrobial resistance genes.Results:Among the 7 tested iNTS isolates, we found one Salmonella Typhimurium strain and two Salmonella Ⅰ 4, [5], 12: i:- strains whose MLST types were ST34, two Salmonella Enteritidis strains, one Salmonella Corvallis strain and one strain of unknown serotype with the antigenic formulae of Ⅰ 4, [5], 12: d:- (ST279 type). Six of seven strains were monophasic and the deletion or pseudogenization of Salmonella Flagellum gene might contribute to the enhancement of Salmonella invasiveness. None was found to be resistant to tigarcycline, aztreonam, amikacin, cephalosporins and carbapenem and one Salmonella Typhimurium strain was found to be co-resistant to eight classes of antimicrobials at the same time. Resistance genes were generally in accord with relative resistant phenotypes. Conclusion:The iNTS strains could show high level multi-drug resistance, indicating that close attention should be paid to the resistance of iNTS though the overall resistance might be relatively not high.

Objective To elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana(S. Indiana)isolated from retail chicken carcasses in six provinces of China. Methods A total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing. Results Among 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing:11.67%(99/874),Jilin:8.20%(60/726), Guangdong: 1.39%(7/502),Jiangsu: 15.61%(42/260),Shaanxi: 8.56%(16/186),Inner Mongolia: 0(0/81)), and 224 of them were identified as S. Indiana. 213(95.10%)isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86%(40/224)of them were resistant to all antibiotics tested except carbapenems, and 50.89%(114/224)of them resistant to 9 antibiotics, additionally, 25.45%(57/224)of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions. Conclusion The results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Objective:To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods:A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results:The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates.Conclusion:Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

Objective To elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana(S. Indiana)isolated from retail chicken carcasses in six provinces of China. Methods A total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing. Results Among 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing:11.67%(99/874),Jilin:8.20%(60/726), Guangdong: 1.39%(7/502),Jiangsu: 15.61%(42/260),Shaanxi: 8.56%(16/186),Inner Mongolia: 0(0/81)), and 224 of them were identified as S. Indiana. 213(95.10%)isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86%(40/224)of them were resistant to all antibiotics tested except carbapenems, and 50.89%(114/224)of them resistant to 9 antibiotics, additionally, 25.45%(57/224)of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions. Conclusion The results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Objective:To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods:A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results:The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates.Conclusion:Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

To construct TeI3c/4c-based and temperature-inducible gene inactivation system (Thermotargetron) and to apply it to gene inactivation of mesophilic bacteria. The subunit of flagellum (fliC) and C4 dicarboxylate orotate:H⁺ symporter (dctA) genes were chosen as targets in the genome of Escherichia coli HMS174 (DE3) strain. According to recognition roles of TeI3c/4c intron, the fliC489a, fliC828s, fliC1038s and dctA2a sites were chosen as target sites. Gene-targeting plasmids were constructed based on pHK-TT1A by using overlap PCR method and transformed into HMS174 cells. An aliquot mid-log phase cultures of the transformants were shocked at 48 °C and plated on LB plate (containing chloramphenicol). Afterwards, gene mutants were screened by using colony PCR and DNA sequencing. After the mutants were obtained, the phenotypes of ΔfliC and ΔdctA gene mutants were characterized by using agar puncture and carbon metabolism experiments. Colony PCR and sequencing results show that TeI3c/4c intron was inserted in the designed sites of fliC and dctA genes. The gene-targeting efficiency of Thermotargetron system was 100%. Phenotype verification experiments of the mutants demonstrated that the cell motility of all ΔfliC mutants was damaged and the malate assimilation ability of ΔdctA mutant was deprived comparing to wild-type HMS174 strain. In our study, a temperature-inducible and high-efficiency gene inactivation system was established for mesophilic bacteria. This system could achieve high efficiency and precise gene inactivation by modulation of the incubation duration of the transformants at 48 °C.