Objective To establish a sensitive real-time quantitative PCR assay with TaqMan probe for rapid detection of mcr-1 gene in clinical isolated strains. Methods According to the mcr-1 gene sequence, a pair of specific primers and a TaqMan probe were designed. Moreover, a recombinant plasmid with mcr-1 gene was constructed as the positive standard. TaqMan probe-based fluorescence quantitative PCR assay was used to detect the colistin resistance gene mcr-1. The sensitivity, repeatability and specificity of the assay were evaluated. Results There was a good linear relationship between the initial template amount and Ct value (R2>0. 999). The lower limit of detection was 10 copies/μL, which was 100 times more sensitive than the conventional PCR. Results of test for specificity showed that only the strains carrying the mcr-1 gene were positive, while the remaining strains were negative. Coefficients of variation of intra-and inter-group repeatability tests were less than 1％. Two out of 150 clinical isolated strains carried mcr-1 re-sistance gene and both of them were identified as Escherichia coli. Conclusion TaqMan probe-based fluo-rescence quantitative PCR for the detection of colistin resistance gene mcr-1 was established with strong spe-cificity, high sensitivity and good repeatability. It could be used for the specific detection of clinical drug-re-sistant strains positive for mcr-1 gene and provide reference for pharmacotherapy.

Objective To evaluate the immunogenicity and safety of a split-virion influenza vac-cine after its manufacturing process was improved. Methods The immunological non-inferiority of trial to control vaccines was evaluated in 240 subjects aged 3-<18 years. Another 360 subjects aged 18-<60 years were randomly divided into three groups that were respectively given three consecutive lots of trail vaccine to assess the consistency of immunogenicity. Results There were 4. 17% of the subjects aged 3-<18 years showed adverse reactions following immunization with trail vaccine and it was not significantly different from that of the control group (P>0. 05). No significant difference in seroconversion rate, geometric mean titer (GMT) of haemagglutination inhibition antibodies(HIAb) or protection rate was found between trial and control groups (P>0. 05). No significant difference in seroconversion rate or HIAb GMT was found among the three lots (P>0. 05). Conclusion The trial influenza vaccine has good safety, immunogenicity and lot-to-lot consistency after the manufacturing process was improved.

Objective:To establish the normal values of water-perfused high resolution esophageal manometry (HREM)(GAP-36A) at resting period, water swallowing, semisolid swallowing and solid swallowing in Chinese population.Methods:From September 1, 2019 to June 30, 2020, 91 healthy volunteers receiving water-perfused HREM (GAP-36A) at resting period, water swallowing, semisolid swallowing and solid swallowing were selected from 9 hospitals (Union Hospital, Tongji Medical College, Huazhong University of Science and Technology; the First Affiliated Hospital of Dalian Medical University; the Second Hospital of Hebei Medical University; the Second Affiliated Hospital, Naval Medical University; the First Affiliated Hospital, Sun Yat-sen University; the First Affiliated Hospital, University of Science and Technology of China; Aviation General Hospital of China Medical University; the Affiliated Hospital of Medical School of Nanjing University and the First People′s Hospital of Yichang). Parameters included the position of the upper and lower edges of the upper esophageal sphincter (UES) and lower esophageal sphincter (LES), the length of the LES and UES, the position of the pressure inversion point (PIP), the resting pressure of UES and LES and swallow-related parameters such as the distal contraction integral (DCI), 4 s integrated relaxation pressure (IRP), distal latency (DL) and UES residual pressure. One-way analysis of variance, post-hoc test and sum rank test were used for statistical analysis.Results:A total of 87 healthy volunteers were enrolled, including 40 males and 47 females, aged (38.5±14.2) years old (ranged from 19 to 65 years old). The position of the upper and lower edges of the LES was (42.7±2.8) and (45.6±2.8) cm, respectively, the length of the LES was (2.9±0.4) cm, and the position of PIP was (43.3±2.8) cm. The position of the upper and lower edges of the UES was (18.1±3.0) and (22.6±2.0) cm, respectively, and the length of the UES was (4.8±1.0) cm. The resting pressure of LES and UES was (17.4±10.7) and (84.1±61.1) mmHg (1 mmHg=0.133 kPa), respectively. The DCI value at solid swallowing was higher than those at water swallowing and semisolid swallowing ((2 512.4±1 448.0) mmHg·s·cm vs. (2 183.2±1 441.2) and (2 150.8±1 244.8) mmHg·s·cm), and the differences were statistically significant ( t=-4.30 and -3.74, both P<0.001). The values of 4 s IRP at semisolid swallowing and solid swallowing were lower than that at water swallowing ((4.6±4.1) and (4.9±3.9) mmHg vs. (5.4±3.9) mmHg), and the differences were statistically significant ( t=3.38 and 2.09, P=0.001 and 0.037). The DL at water swallowing was shorter than those at semisolid swallowing and solid swallowing ((8.5±1.8) s vs. (9.8±2.2) and (10.6±2.8) s), and the DL at semisolid swallowing was shorter than that at solid swallowing, and the differences were statistically significant ( t=-10.21, -13.91 and -4.68, all P<0.001). The UES residual pressure at water swallowing was higher than those at semisolid swallowing and solid swallowing (9.5 mmHg, 6.5 to 12.3 mmHg vs. 8.0 mmHg, 4.5 to 11.7 mmHg and 5.5 mmHg, 2.0 to 9.3 mmHg), and the UES residual pressure at semisolid swallowing was higher than that at solid swallowing, and the differences were statistically significant ( t=3.48, 10.30 and 6.35, all P<0.001). Conclusions:The normal values of water-perfused HREM (GAP-36A) in Chinese population at resting period, water swallowing, semisolid swallowing and solid swallowing can provide a reference basis for clinical diagnosis and treatment for patients receiving water-perfused HREM examination.

Objective To evaluate the safety of a Chinese thimerosal-free trivalent split influenza virus vaccine after being marketed in a large population. Methods Through the information management system of adverse event following immunization (AEFI), the adverse events in healthy people aged 6 months and above who were vaccinated with split influenza virus vaccine in Hubei Province from October to December 2015 were collected. The data was analyzed by descriptive methodology. Results From October 1, 2015 to June 30, 2016, among the 227 920 people in Hubei Province who were vaccinated with split influenza virus vaccine, the common adverse reactions were mainly fever, redness, irritability, pain and itching. Four cases of AEFI were passively observed and reported in the system, with a reporting rate of 1.76/100 000, among which 3 cases were anaphylactic rash and 1 case was optic neuritis. Conclusion The Chinese thimerosal-free trivalent split influenza virus vaccine used in Hubei Province had a good safety record and is suitable for the general vaccination of people without vaccination contraindications.