The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.
Humans ; Tigecycline/pharmacology* ; Escherichia coli/metabolism* ; Reactive Oxygen Species/therapeutic use* ; Plasmids ; Anti-Bacterial Agents/metabolism* ; Escherichia coli Infections/microbiology* ; Bacteria/genetics* ; Microbial Sensitivity Tests

ObjectiveTo analyze the genetic characteristics of the hemagglutinin （H） gene of measles virus （MeV） in Shanghai， 2001‒2018. MethodsNasopharyngeal swab specimens were collected from suspected measles cases reported in Shanghai from 2001 to 2018， and the isolation of measles virus was conducted with Vero/hSLAM cell line. RT-PCR amplification and sequencing were conducted after RNA extraction to analyze the genetic characteristics of the complete H gene. ResultsIn total， 5 665 nasopharyngeal swab samples were collected by suspected measles case surveillance from 2001 to 2018， and 1 394 measles virus strains were isolated. The homology of nucleotide acid and amino acid among 349 representative measles virus isolates was 87.4%‒100.0% and 85.1%‒100.0%， respectively. The homology of nucleotide acid and amino acid between representative measles virus isolates and China vaccine strain （S191） was 85.7%‒100.0% and 84.1%‒100.0%， respectively. All the sub-genotype H1a MeV isolates had an amino acid substitution （Ser240Asn）， which removed a predicted N-linked glycosylation site. ConclusionMost of the MeV isolates are sub-genotype H1a analyzed based on H gene， which are identical to those of the N gene. The predicted amino acid sequences of the H protein are relatively conserved at most of the functionally significant amino acid positions.

Objective:To explore genetic characterization and circulation dynamic changes of Echovirus 11(Echo11)isolated from environmental sewage surveillance.Methods:The VP1 coding region of Echo11 isolated from environmental surveillance in Shanghai from 2012-2019 was amplified and sequenced. Homology analysis and phylogenetic analysis on the Echo11 VP1 sequences were performed with reference strains in acute flaccid paralysis (AFP) surveillance, healthy children surveillance and reference strains.Results:A total of 156 strains of Echo11 were isolated from different sources in Shanghai, of which 136 strains were isolated from environmental sewage in 2012-2019, with the seasonal peak mainly in summer and autumn; 40.3% of the strains from different sources in Shanghai had the 54th amino acid mutation. There are 5 subgenotype of Echo11 from different sources in Shanghai, i. e. A1, A2, C1, C3 and D5. During 2012, there was co-circulation of A1 subgenotype Echo11 among environmental sewage, AFP cases and healthy children. From 2012 to 2015, the dominant transmission chain of Echo11 was A1 subgenotype. Since 2016, the dominant transmission chain of echo11 has gradually changed to D5 subgenotype.Conclusions:Environmental surveillance truly reflects the circulation of human enterovirus(HEV), which has practical significance for the prediction and early warning of HEV related diseases.

Objective: To observe ascitic interleukin-7 expression level in cirrhotic patients complicated with spontaneous bacterial peritonitis, and to detect the effect of recombinant human IL-7 on CD4⁺ and CD8⁺T lymphocyte function. Methods: A total of 84 patients with liver cirrhosis who were hospitalized from August 2017 to April 2018 were selected. Among them, 51 cases were complicated with cirrhosis and untainted ascites, and 33 cases were cirrhosis complicated with spontaneous bacterial peritonitis. Peripheral blood and ascites were collected routinely. The levels of IL-7 in peripheral blood and ascites were measured by enzyme-linked immunosorbent assay. CD4⁺T cells and CD8⁺T cells were purified from ascites, and were stimulated with recombinant IL-7. Cellular proliferation, key transcription factors for mRNA, and cytokines production by CD4⁺T cells in response to IL-7 stimulation was measured. mRNA expression corresponding to perforin, granzyme B, and granulysin as well as cytokines production by CD8⁺T cells was also measured in response to IL-7 stimulation. Cytolytic and non-cytolytic activity of CD8⁺T cells in response to IL-7 stimulation was also investigated in both direct and indirect contact co-culture system. Measurement data of the normal distribution were compared between the two groups by Student’s t-test and the data before and after stimulation were compared by paired t-test. Measurements that did not conform to normal distribution were compared between the two groups using Mann-Whitney U test, and data before and after stimulation were compared using Wilcoxon paired test. Results: There was no significant statistical difference in serum IL-7 levels between the two groups [(5 001 ± 1 458) pg/ml vs. (4 768 ± 1 128) pg/ml, P = 0.41]. The level of ascitic IL-7 in cirrhotic patients complicated with SBP was significantly lower than cirrhosis patients with untainted ascites [(966.4 + 155.8) pg/ml vs. (792.1 + 126.4) pg/ml, P < 0.01]. Recombinant IL-7 stimulation promoted the proliferation of CD4⁺ and CD8⁺T cells from ascites in patients with liver cirrhosis complicated by SBP. T-bet mRNA relative expression and IFN-γ secretion in CD4⁺T cells was also elevated in response to IL-7 stimulation in vitro. Moreover, IL-7 stimulation also increased the mRNA expressions of perforin, granzyme B, and granulysin as well as productions of IFN-γ and TNF-α by CD8⁺T cells. Recombinant IL-7 stimulation elevated cytolytic and non-cytolytic activity of CD8⁺T cells from ascites in patients with liver cirrohosis complicated by SBP, which manifested as increased target cell death and IFN-γ production in both direct and indirect contact co-culture system. Conclusion Ascitic IL-7 promotes T lymphocyte function in patients with liver cirrhosis complicated with SBP.

Objective: To evaluate the immunogenicity of different strains of inactivated poliomyelitis vaccines (IPV) by sequential program. Methods: This parallel-group controlled trial was conducted in immunization clinics in Shanghai from March 2016 to September 2017. Sabin strains inactivated poliomyelitis vaccines (sIPV), WPV strains inactivated poliomyelitis vaccines (wIPV) and live poliomyelitis Type Ⅰ Type Ⅲ vaccine (bOPV) as the investigational vaccine were used at 2, 3, 4 months old in 325 infants in Shanghai. Infants vaccinated by four sequential program were divided into 4 groups: sIPV+sIPV+bOPV, sIPV+wIPV+bOPV, wIPV+sIPV+bOPV and wIPV+wIPV+bOPV. A total of 230 investigators′ blood samples were collected before primary immunization and 163 investigators′ blood samples were collected after primary immunization. A total of 151 investigators (36, 44, 30 and 41 in each group) finished primary immunization and blood sampling before and after the primary immunization. The geometric mean titer (GMT) of poliovirus typesⅠ and Ⅲ neutralizing antibody was tested and calculated, and the positive results of antibody before and after primary immunization were analyzed. Results: Among the 151 investigators, the age were (2.27±0.61) months and birth weight were (3.27±0.43) kg, and 70 were male. The positive rates of typeⅠwas 98.68% (149 cases), and type Ⅲ was 97.35% (147 cases); the number of investigators tested in each group was 36, 44, 30 and 41, respectively; the positive rates of typeⅠwas 97.22% (35 cases), 100.00% (44 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.345); the positive rates of type Ⅲ were 97.22% (35 cases), 95.45% (42 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.614). Conclusion Using sIPV and wIPV simultaneously or alternately for sequential immunization of poliomyelitis vaccines showed good immunogenicity for infants at appropriate age.

Objective To evaluate the immunogenicity of different strains of inactivated poliomyelitis vaccines (IPV) by sequential program. Methods This parallel?group controlled trial was conducted in immunization clinics in Shanghai from March 2016 to September 2017. Sabin strains inactivated poliomyelitis vaccines (sIPV), WPV strains inactivated poliomyelitis vaccines (wIPV) and live poliomyelitis TypeⅠTypeⅢvaccine (bOPV) as the investigational vaccine were used at 2, 3, 4 months old in 325 infants in Shanghai. Infants vaccinated by four sequential program were divided into 4 groups: sIPV+sIPV+bOPV, sIPV+wIPV+bOPV, wIPV+sIPV+bOPV and wIPV+wIPV+bOPV. A total of 230 investigators′blood samples were collected before primary immunization and 163 investigators′ blood samples were collected after primary immunization. A total of 151 investigators (36, 44, 30 and 41 in each group) finished primary immunization and blood sampling before and after the primary immunization. The geometric mean titer (GMT) of poliovirus typesⅠ and Ⅲ neutralizing antibody was tested and calculated, and the positive results of antibody before and after primary immunization were analyzed. Results Among the 151 investigators, the age were (2.27±0.61) months and birth weight were (3.27±0.43) kg, and 70 were male. The positive rates of typeⅠwas 98.68% (149 cases), and type Ⅲ was 97.35% (147 cases); the number of investigators tested in each group was 36, 44, 30 and 41, respectively; the positive rates of typeⅠwas 97.22% (35 cases), 100.00% (44 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.345); the positive rates of typeⅢwere 97.22% (35 cases), 95.45% (42 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.614). Conclusion Using sIPV and wIPV simultaneously or alternately for sequential immunization of poliomyelitis vaccines showed good immunogenicity for infants at appropriate age.

Objective To evaluate the immunogenicity of different strains of inactivated poliomyelitis vaccines (IPV) by sequential program. Methods This parallel?group controlled trial was conducted in immunization clinics in Shanghai from March 2016 to September 2017. Sabin strains inactivated poliomyelitis vaccines (sIPV), WPV strains inactivated poliomyelitis vaccines (wIPV) and live poliomyelitis TypeⅠTypeⅢvaccine (bOPV) as the investigational vaccine were used at 2, 3, 4 months old in 325 infants in Shanghai. Infants vaccinated by four sequential program were divided into 4 groups: sIPV+sIPV+bOPV, sIPV+wIPV+bOPV, wIPV+sIPV+bOPV and wIPV+wIPV+bOPV. A total of 230 investigators′blood samples were collected before primary immunization and 163 investigators′ blood samples were collected after primary immunization. A total of 151 investigators (36, 44, 30 and 41 in each group) finished primary immunization and blood sampling before and after the primary immunization. The geometric mean titer (GMT) of poliovirus typesⅠ and Ⅲ neutralizing antibody was tested and calculated, and the positive results of antibody before and after primary immunization were analyzed. Results Among the 151 investigators, the age were (2.27±0.61) months and birth weight were (3.27±0.43) kg, and 70 were male. The positive rates of typeⅠwas 98.68% (149 cases), and type Ⅲ was 97.35% (147 cases); the number of investigators tested in each group was 36, 44, 30 and 41, respectively; the positive rates of typeⅠwas 97.22% (35 cases), 100.00% (44 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.345); the positive rates of typeⅢwere 97.22% (35 cases), 95.45% (42 cases), 96.67% (29 cases) and 100.00% (41 cases) (P=0.614). Conclusion Using sIPV and wIPV simultaneously or alternately for sequential immunization of poliomyelitis vaccines showed good immunogenicity for infants at appropriate age.

Objective: To analyze the genetic characterization of glycoprotein M(gM.),glycoprotein L(gL) of varicella zoster virus. Methods: According to the program of "Ministry of Science and Technology of China" , Based on the 12 suspected VZV patients monitored in Beijing (1 case), Shanghai (5 cases), Jilin (2 cases), Qinghai (1 case), Guangdong (2 case) and Sichuan (case) in 2007-2015. A total of 12 Vesicle fluid and throat swab samples were collected. Positive samples were identified by Agarose gel electrophoresis and two glycoprotein genes were amplified by polymerase chain reaction (PCR). Nucleotide sequences were determined and analyzed by PCR amplification of VZV positive specimens V-OKA-BK of the domestic varicella attenuated live vaccine and the Varilrix-1 of the imported attenuated live vaccine. Nucleotide sequences of VZV positive specimens, vaccine strains (V-OKA-BK, varilrix-1) and GenBank foreign wild strains (41 strains), parent strains (P-oka), vaccine strains (V-oka, Varilrix, Varivax) were compared using BioEdit and MEGA 5.0. Results: 12 specimens were VZV positive. Compared with the vaccine strains and the parent strains, the GM gene of 1 positive specimen had radical mutation at 86686 sites, which resulted in amino acid mutation, 5 positive specimens had base mutation at 87844 sites, and 30 strains of foreign wild strains had the same variation at 87 844 sites. 1 positive specimens of gL gene in 101245 sites had base mutation, and led to amino acid mutation, 6 positive specimens at 101624, 101625, 101626 sites had base of loss and the foreign wild strains in these 3 sites had the same variation. Compared with the vaccine strains, the nucleotide and amino acid homology of gM of 12 VZV positive specimens were 99.2%-100% and 98.2%-100%, respectively, and gL of those were 99.3%-100% and 98.6%-100%, respectively. Compared with 41 strains of foreign wild strains, homology of gM's nucleotides and amino acid were 99.3%-100% and 98.5%-100%, respectively; 99.1%-100% and 98.6%-100% for gL. The results of phylogenetic analysis showed that 7 VZV positive samples were on the same branch with 4 vaccine strains and p-oka strain. Based on gL, 12 VZV positive samples were on the same branch as the vaccine strains and p-oka strain. Conclusion This study demonstrates that the genes of gM, gL are highly conserved and remain stable immunogen, which may be involved in the attenuation of VZV and need to be further researched.

Objective: To analyze the molecular epidemiological characteristics of rubella virus wild strains isolated in Shanghai during 2011-2017. Methods: Throat swabs were collected from suspected measles or rubella patients in Shanghai during 2011-2017, which were identified as rubella and excluded measles by laboratory tests. Throat swabs were used to conduct cell culture for rubella virus isolation. After identification by RT-PCR, the nucleic acid of gene E1 of rubella virus was amplified and sequenced, followed by molecular epidemiological analysis. Results: Totally 395 strains of rubella virus were isolated from 684 throat swabs. Compared 377 isolates with the WHO reference strains of all genotypes, phylogenetic tree was constructed based on the amplified 739 nucleotides sequences. These isolates were characterized as two genotypes respectively, 109 strains were defined as genotype 1E which were closer to the WHO reference strain from China (RVi/Shandong.CHN/0.02/), and others were genotype 2B while 5 strains of them were defined as a lineage. Most of the nucleotide mutations were nonsense mutation, and the amino acid sequences were highly conserved. All the genotype 1E rubella viruses except one strain had the same mutation at aa338 site. Conclusions Two genotypes of rubella virus circulated in Shanghai during 2011-2017.Genotype 1E appeared to be the predominant genotype during 2011-2013, genotype 2B was continuously existing since being found in 2011 and appeared to be the predominant genotype during 2014-2016.

Objective: To explore the time and genotype distribution of human enterovirus (HEV) isolated from sewage in Shanghai in 2013-2014. Methods: One sewage sample each was collected from two local sewage plants located in Minhang District and Jiading District on the same day at the day 24-28 of every month from 2013 to 2014. Each sample weighed 1 L. The specimens were concentrated by anionic membrane absorption, eluted with beef extract solution, and then used to inoculate RD, HEp-2, and L20B cell lines. A total of 249 enterovirus strains were isolated from sewage samples during the study period, including 185 non-polio enterovirus (NPEV) and 64 poliovirus (PV) strains, which were identified as vaccine strains. RT-PCR and Sanger sequencing were performed to identify HEV genotypes. Homologous analysis of VP1 sequences was conducted using BioEdit (version 7.0.0). Phylogenetic analysis was performed using the neighbor-joining method based on the alignment of VP1 gene sequences using MEGA (version 4.0.2). Results: Among 185 NPEV strains, 178 strains were successfully sequenced and classified into 15 genotypes, including coxsackievirus group B (CVB) 2, 3, and 5; enteric cytopathic human orphan (ECHO) virus 1, 3, 6, 7, 11, 13, 19, 20, 24, 25, and 30; and coxsackievirus group A 4. CVB5 and ECHO6 genotypes accounted for 33.5% (56 strains) and 24.9% (43 strains) of NPEV isolates, respectively. During the study period, HEV isolates were mainly isolated in summer and autumn in Minhang District. ECHO6 strains were frequently isolated from June 2013 to July 2014. Thereafter, the number of ECHO6 strains gradually reduced in the second half of 2014. CVB5 strains demonstrated scattered distribution from 2013 to the first half of 2014 and gradually increased in the second half of 2014. The distribution of ECHO6 and CVB5 strains in Jiading District was similar to that in Minhang District. In 2013-2014, CVB5 strains comprised C6 and C8 subgenotypes, which belong to two transmission chains and show large differences compared with foreign strains isolated during the same period. ECHO6 strains comprised C6, C8, and D9 subgenotypes, which belong to three transmission chains. Moreover, ECHO6 subgenotype D9 was a dominant subgenotype in Shanghai, with broad geographical distribution both at home and abroad. Conclusion Poliovirus was identified as a vaccine strain in environmental surveillance from June 2013 to April 2014 in Shanghai. Several transmission strains of ECHO6 and CVB5 were identified, which were the dominant serotypes.