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Objective:Analysis of the antibiotic resistance profiles and molecular typing of Salmonella typhimurium ( S. typhimurium) isolated in Wuxi city from 2011 to 2018. Methods:A total of 109 S. typhimurium isolates were detected from different types monitoring samples in Wuxi city from 2011 to 2018. Microbroth dilution method was used to test antimicrobial susceptibility of S. typhimurium for 17 antimicrobial agents. Pulsed field gel electrophoresis (PFGE) was used to conduct molecular typing. Statistical analysis was carried out using Chi-square test. Results:Tetracycline-resistance and ampicillin-resistance were most frequency in 109 S. typhimurium isolates, 69.72% (76/109) and 68.81% (75/109), respectively. For compound sulfamethoxazole, chloramphenicol, ciprofloxacin, ampicillin/sulbactam, azithromycin, nitrofurantoin, cefotaxime and aztreonam, the resistance rates were 23.85%(26/109), 22.02%(24/109), 11.93%(13/109), 4.59%(5/109), 3.67%(4/109), 3.67%(4/109), 0.92%(1/109), 0.92%(1/109), respectively. All isolates were susceptible to amikacin, ertapenem, imipenem, meropenem, ceftazidime and ceftazidime-avibactam. Azithromycin-resistance isolates were decreasing year by year gradually. The aztreonam and cefotaxime-resistant isolates were found since 2018, while chloramphenicol and compound sulfa-resistant isolates showed upward trend simultaneously. Conclusions:S. typhimurium in Wuxi city exhibited highly resistant to tetracycline and ampicillin. The significant variability existed between genotype and phenotype of S. typhimurium.
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Zinc finger proteins (ZNFs) belong to the largest transcriptional factor family in human genome. ZNFs are widely involved in the development and progression of digestive system cancers by promoting or inhibiting carcinogenesis. Studies have shown that the abnormal expressions of various ZNFs are closely related to the clinicopathologic features and prognosis of patients with digestive system cancers, including gastric cancer, liver cancer, colorectal cancer and pancreatic cancer. Exploring the underlying mechanism of ZNFs will help to provide new targets for clinical treatment of digestive system cancers.
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Objective To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province.Methods Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27,2016 was reversely transcribed to cDNA,and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR.Amplification products were sequenced for the analysis of genetic characteristics.Results Based on sequence alignment,the variant shared a high level of identity with the strain G Ⅱ.g isolated in Spain and Finland (98.7％) in the RNA-dependent RNA polymerase region,and with the strain G Ⅱ.1 isolated in American (99.4％) in the VP1.The recombination was determined by using software Simplot,and the breakpoint of recombination was located in the ORF 1/2 overlap region at position 5 106 of VP 1.The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ,but a unique amino acid change was detected at position 132 (N-S).Conclusion The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant G Ⅱ.g-G Ⅱ.1.
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Objective To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province.Methods Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27,2016 was reversely transcribed to cDNA,and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR.Amplification products were sequenced for the analysis of genetic characteristics.Results Based on sequence alignment,the variant shared a high level of identity with the strain G Ⅱ.g isolated in Spain and Finland (98.7％) in the RNA-dependent RNA polymerase region,and with the strain G Ⅱ.1 isolated in American (99.4％) in the VP1.The recombination was determined by using software Simplot,and the breakpoint of recombination was located in the ORF 1/2 overlap region at position 5 106 of VP 1.The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ,but a unique amino acid change was detected at position 132 (N-S).Conclusion The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant G Ⅱ.g-G Ⅱ.1.
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We analyzed the pathogenic characteristics of Salmonella strains isolated from diarrhea patients in Wuxi City,Jiangsu Province,China and compared the differences among pulse field gel electrophoresis (PFGE) patterns of main serotype strains,so as to provid scientific basis for disease control.After biochemical identification of the Salmonella strains isolated from infectious diarrhea patients in Wuxi in 2015,drug susceptibility test,serotyping and PFGE were applied to analyze these strains.Results showed that a total of 32 Salmonella strains were detected from 756 diarrhea specimens with a positive rate of 4.23 ％.The infection occurred more frequently between May and October and adults aged more than 60 years old affected mostly.There was no significant difference between genders in infected population.The drug susceptibility test indicated that the antibiotic resistance rate of these Salmonella strains to ampicillin (56.25 ％) was the highest,and to ciprofloxacin(6.25 ％)and Ceftazidime (6.25％) were the lowest.The 32 Salmonella strains belonged to 11 serotypes,and S.enteritidis(31.25％)and S.typhimurium(21.88％) were the predominant serotypes.PFGE showed that the pattern similarity of all S.enteritidis was more than 85 ％;PFGE patterns of S.typhimurium were different.In conclusion,the infection of Salmonella from diarrhea patients in Wuxi City had obvious season and age specific distribution,and the most prevalent serotype of Salmonella was the S.enteritidis.It is necessary to strengthen the surveillance of Salmonella concurrently in food and environment.
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<p><b>OBJECTIVE</b>To study both the epidemiologic and molecular characteristics of outbreaks caused by norovirus (NoV) with its variants, in Jiangsu.</p><p><b>METHODS</b>67 specimens from seven gastroenteritis outbreaks were collected from October 2012 to March 2013 in Jiangsu. NoV gene group was detected by Real-Time RT-PCR. NoV portions of RdRp gene and VP1 gene were amplified under RT-PCR.</p><p><b>RESULTS</b>Seven gastroenteritis outbreaks were caused by NoV. Among all the fecal specimens,45 (67.2%) showed positive to NoV G II. Study on the genotype was conducted through analyzing the nucleotide sequence of RdRp gene. Based on the RdRp region, 7 strains appeared to be G II, with 3 and 38 strains belonged to G II.4--Sydney variants. Results from phylogenetic analysis confirmed that 38 variants shared 99% identity with G II.4--Sydney. We also amplified the VP1 genes from 6 variants and comparing with 9 epidemic strains on the sequence amino acid sequence. All the strains showed mutation in amino acid sequence at some key sites which were closely related to the forming of neutralizing epitopes.</p><p><b>CONCLUSION</b>The short interval periods between all 7 NoV outbreaks with identical viral strain indicated the emergence of a new NoV variant in Jiangsu province,that had caused a number of epidemics abroad. Results from our study suggested that the development of monitoring programs on this novel G II.4--Sydney variant should be a part of the NoV surveillance in Jiangsu province or even in the country.</p>
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Humans , Amino Acid Sequence , Caliciviridae Infections , Epidemiology , Virology , China , Epidemiology , Disease Outbreaks , Gastroenteritis , Epidemiology , Virology , Genotype , Norovirus , Genetics , Phylogeny , RNA, ViralABSTRACT
<p><b>OBJECTIVE</b>To monitor the seasonal distribution of influenza types and subtypes in Wuxi area during 2005-2008, and to investigate the variation in hemagglutinin (HA) genes of A/H3N2 strains in 2008.</p><p><b>METHODS</b>Nose-throat swab specimens were collected in Wuxi area from flu-like patients from outpatient departments of hospitals as well as from clustering flu-like outbreak patients from workspace, followed by MDCK cell inoculation. Types and subtypes of positive influenza isolates were identified using standard antiserum. We then sequenced the HA genes for H3 subtype influenza viruses isolated from 2008 specimens to investigate the variation in HA genes.</p><p><b>RESULTS</b>During 2005 and September 2008, 435 strains of influenza viruses were isolated from flu-like patients in Wuxi Area, among which 164 isolates are of A/H1N1 subtype, 80 isolates are of A/H3N2 subtype, and 191 isolates are of B type. These types/subtypes have significant seasonal distributions. Sequences of HA genes for H3 subtype show that the 9 strains isolated in Wuxi area are similar to those of strains isolated in Shanghai within the same period. Many of the sequences belong to the same branch of the phylogenetic tree, and are similar to sequences of vaccine strains in WHO 2008-2009 repositories.</p><p><b>CONCLUSION</b>A/H1N1, A/H3N2 and B still attribute to most of the sporadic and local outbreaks of influenza infection in Wuxi area in recent years. HA genes of A/H3N2 strains isolated in Wuxi area are similar to those of strains isolated in Shanghai in the same period, and also similar to those of vaccine strains recommended by WHO for 2008-2009.</p>
Subject(s)
Animals , Humans , Cell Line , China , Epidemiology , Genetic Variation , Hemagglutinin Glycoproteins, Influenza Virus , Genetics , Influenza A Virus, H3N2 Subtype , Classification , Genetics , Influenza, Human , Epidemiology , Virology , Molecular Sequence Data , Phylogeny , Population SurveillanceABSTRACT
Objective: To investigate G-CSF expression and rhG-CSF's effects on cell proliferation and its mechanism in human solid carcinoma cell lines. Methods: G-CSF expression was detected by human G-CSF ELISA Kit. Cell proliferation promoted by rhG-CSF was studied by cell count and MTT. The influence of rhG-CSF on KB cell cycle and apoptosis was analysed by flow cytometry. G-CSF receptor expression was detected by immunocytochemistry. Results: Cell line T-24 produced large amount of G-CSF; rhG-CSF promoted cell line KB proliferation in a dose-dependent manner and reached its maximal effect at a concentration of 100 ng/mL (P < 0.05); rhG-CSF antagonized G0/G1 phase block and reduced apoptosis rate of KB cells. Conclusion: Cell line T-24 expresses G-CSF; rhG-CSF promotes, KB cell proliferation by binding its G-CSF receptor, antagonizing G0/ G1 phase block and inhibiting apoptosis.
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<p><b>OBJECTIVE</b>To evaluate the effect of Avastin and adenovirus-thymidine kinase/ Ganciclovir (Ad-TK/GCV) suicide gene system on nasopharyngeal carcinoma in vivo and in vitro.</p><p><b>METHODS</b>The expression of vascular endothelial growth factor (VEGF) by CNE1 cell line was detected by VEGF ELISA. The effect of Avastin and Ad-TK/GCV on CNE1 cell was detected by methyl thiazolyl tetrazolium (MTT) assay. Flow cytometry analysis and Hoechst 33342 staining were adopted to explore the killing mechanism of Ad-TK/GCV. The nude mice models of CNE1 cell xenografts were established. After intra-tumoral injection of PBS, Avastin, Ad-TK/GCV, Ad-Lac-Z/GCV and Ad-TK/GCV + Avastin, tumor volume was measured and tumor inhibitory rate was calculated. Then the tumors were removed and subjected to histological examination.</p><p><b>RESULTS</b>CNE1 cells could produce VEGF. Avastin had no direct effect on CNE1 cells. The killing effect of Ad-TK/GCV increased with the increase of Ad-TK multiple of infection and the prodrug concentration, which was enhanced by the existence of bystander effect. Compared with control group, the death cell rate (P = 0.000) and apoptosis cell rate (P = 0.000) had significant difference. The study in vivo showed the tumors treated with Avastin, Ad-TK/GCV and Ad-TK/GCV + Avastin grew slowly compared with control. Tumor volume of treated groups was significantly smaller than that of control (all P < 0.05 or P = 0.000). Tumor weight of treated groups was significantly lower than that of control (all P = 0.000). The histological examination showed local necrosis in Ad-TK/GCV group and Ad-TK/GCV + Avastin group, poor angiogenesis in Avastin group and Ad-TK/GCV + Avastin group.</p><p><b>CONCLUSIONS</b>Avastin had no direct effect on CNE1 cells in vitro. Ad-TK/GCV suicide gene system killed NPC cells by inducing cell necrosis and apoptosis, which could be enhanced by the existence of bystander effect. Avastin and Ad-TK/GCV suicide gene system could inhibit the growth of NPC CNE1 cell xenografts. Combination therapy had a synergic effect.</p>
Subject(s)
Animals , Female , Humans , Male , Mice , Adenoviridae , Genetics , Antibodies, Monoclonal , Therapeutic Uses , Antibodies, Monoclonal, Humanized , Bevacizumab , Ganciclovir , Genes, Transgenic, Suicide , Genetic Therapy , Mice, Inbred BALB C , Mice, Nude , Nasopharyngeal Neoplasms , Therapeutics , Thymidine Kinase , Genetics , Tumor Cells, Cultured , Vascular Endothelial Growth Factor A , Genetics , Therapeutic UsesABSTRACT
OBJECTIVE To establish a simpler method for screening bacterial metallo-?-lactamase(MBL) by comparing Hodge test and double-disk synergy tests(DDSTs),and using 5 inhibitors such as sodium citrate,EDTANa2,EDTAK2,sodium dimercaptopropane sulfonate and mercaptoethanol.METHODS In Hodge test,5 inhibitors of different concentration were added to the imipenem(IMP) disks,the sizes of the inhibition zones were compared.Disk containing IMP and disk containing a metallo-?-lactamase inhibitor were used in DDSTs.The optimal inhibitors concentration and edge-to-edge distance between the two disks were selected.The performances of the Hodge test and the DDSTs were also compared.RESULTS Among the metallo-?-lactamase inhibitors used in this study,1∶15 diluted mercaptoethanol gave the most reproducible and the clearest results when a filter disk containing mercaptoethanol was placed near the IMP disk with the edge distance of 3 mm.CONCLUSIONS Mercaptoethanol-IMP DDSTs are simple,convenient and sensitive methods for screening MBL.
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Objective To clone and express prokaryotic recombinant plasmid of nucleoside triphosphate hydrolase (NTPase) gene of Toxoplasma gondii, and analyze its antigenicity. Method NTPase gene was amplified by PCR from RH strain of T. gondii and cloned into pGEM-T Easy vector. Positive clones were screened and identified by BglⅡ, HindⅢ digestion and sequenced. The target gene was then subcloned into prokaryotic expression vector pBAD-HisB and transformed into E. coli BL21(DE3). The expressed recombinant protein was purified with Ni-NTA agarose and further analyzed by sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) and Western blotting. Results NTPase-Ⅱ gene was specifically amplified, and the homology of DNA sequence was 100% to that in the GenBank. SDS-PAGE showed that the recombinant NTPase protein with correct molecular weight was expressed highly in E.coli BL21(DE3). Western blotting testified that the purified recombinant protein could be specifically recognized by mouse serum immunized with T. gondii and mouse anti-recombinant protein serum. Conclusion The NTPase-Ⅱ gene has been cloned and expressed in E.coli BL21(DE3), and the purified protein of NTPase-Ⅱ gene displays a specific antigenicity.