Objective To investigate the adhesion levels in uropathogenic Escherichia coli with various degree of drug resistance.Methods One hundred strains of Escherichia coli isolated from urine specimen were collected from patients admitted to 4 Grade A tertiary hospitals in Tianjin during March 2012 to October 2015.Escherichia coli were divided into drug sensitive group and drug resistant group by drug sensitivity tests with 50 strains in each group.The expressions of fimH,fimA,fimB genes of type I fimbriae and papA,papB,papC,papGII genes of P fimbriae were detected by polymerase chain reaction(PCR)and real-time fluorescence quantitative RCR (RT-PCR),respectively.Adhesion ability of type I fimbriae and P fimbriae were tested by yeast cell adhesion test and erythrocyte agglutination test.Chi square test and t(Z) test were used to analyze the data.Results The positive rate of papGII in drug resistant group (42.0%) was significantly higher than that in the drug sensitive group (16.0%)(χ2 =8.208,P <0.05),while there were no significant differences in the positive rates of fimH,fimA,fimB,papA,papB and papC genes between two groups(all P >0.05).The expression levels of fimH,fimB and papC genes in the sensitive group were higher than those in the resistant group(Z =3.427,t =5.182 and 8.120,all P <0.05).The adhesion ability of strains carrying type I fimbriae in sensitive group was stronger than that of resistant group (χ2 =5.769,P <0.05).Conclusions The decline in adhesion ability of type I fimbriae in drug resistant E.coli strains is possibly associated with the adaptive cost of bacteria,the transcription and deficiency of other genes encoded by fim and pap gene cluster will also affect the adhesion function of type I pili and type P pili.

Objective To evaluate the application value of polymerase chain reaction (PCR)-fluorescence probe method in identifying genotypes of hepatitis C virus (HCV).Methods One hundred and sixty six serum samples from patients with chronic HCV infection were collected nationwide from March to June 2016.HCV Core-E1 gene region was amplified and sequenced by nested reverse transcription-PCR (RT nested-PCR)and genetic subtypes were analyzed by phylogenetic tree,meanwhile HCV genotypes were also determined by PCR-fluorescent probe method.Kappa test was used to compare the consistency of two methods.Results Among 166 samples detected by RT nested-PCR,the genotype of 66 samples (39.8%) was 1 b,34 (20.5%)was 2a,16 (9.6%)was 3a,27 was 3b (16.2%),23 (13.9%)was 6a.Two samples with 3b genotype detected by RT nested-PCR were identified as 1 b by PCR-fluorescent probe.The consistency rate of two methods was 98.7% (164 /166),there was no significant difference between two methods (χ2 =0.0492,P >0.05).Conclusion PCR-fluorescence probe method can accurately identify HCV genotypes and can be used in clinic.

Objective To investigate the effect of retinoblastoma binding protein 4 (RBBP4)in Sp1 -mediated HIV long terminal repeat(LTR)transcription.Methods RBBP4 expression vector and Sp1 expression vector were respectively co-transfected into 293 T cells with HIV promoter pHIV-LTR-Luc or Sp1 site mutated pHIV-LTR-sp1 -mut by liposome transfection,and the transfected cells were examined by dual luciferase reporter assay system.The effect of RBBP4 on the binding of Sp1 to LTR was further studied by chromatin immunoprecipitation (ChIP)and electrophoretic mobility shift assay (EMSA).Results The relative firefly luciferase activity activated by Sp1 was decreased from 62.5 to 16 at the dose of 500 ng of RBBP4 expression vector (t =14.52,P <0.01 ).When the Sp1 binding sites were mutated,the effects of 100,300 or 500 ng of RBBP4 expression vector on the firefly luciferase activity of HIV LTR were not statistically significance (t =1 .897,2.357 and 3.162,all P <0.05).ChIP results showed that when the binding of RBBP4 on HIV LTR increased,the binding of Sp1 on HIV LTR increased significantly (t =11 .93,P <0.01 ),while the reduced binding of RBBP4 on HIV LTR significantly attenuated the binding of Sp1 onto LTR(t =11 .38,P <0.01 ).The effect of RBBP4 on the binding of Sp1 to DNA in ChIP assays was further verified by EMSA assays.Conclusion RBBP4 can inhibit the Sp1 -mediated HIV LTR transcription in 293 T cells.

Human avian-origin influenza A (H7N9)virus is a novel subtype of avian influenza A virus,which firstly emerged at the end of March 2013 in Shanghai and Anhui province.It rapidly spread in China within a short time,causing high morbidity and mortality,arousing fear and panic in public,and attracting extensive attention worldwide.The analysis of human H7N9 avian influenza virus gene shows a high affinity for α-2,6-linked sialic acid receptors expressed on human respiratory epithelial cells.At present,the sporadic cases of human H7N9 avian influenza virusare occasionally reported with an epidemic peaksat winter and spring.This article reviews clinical features,epidemiology and genetic characteristics of H7N9 avian influenza virus,proving scientific evidences foreffective prevention and control of H7N9 virus infection.

Dendritic cells (DCs)can capture HIV from the mucosal site and carry it to the draining lymph nodes to promote CD4 + T cell infection.DC-SIGN(CD209)plays a vital role during this process. Heroin,methamphetamine and cocaine are the most abused drugs used by drug abusers,which can increase the opportunities of HIV infection.Drugs acting on the corresponding receptors activate the downstream signaling pathway and regulate the expression of DC-SIGN on the surface of DCs,weakening the inhibited effects of immune cells on HIV and promoting HIV infection in many aspects.Given the multiplex effects of drugs on immune function,this article reviews the relationship between abused drugs,DCs and HIV infection,particularly in the signal pathway on immune modulation.

Objective To investigate the clinical features and risk factors of cytomegalovirus (CMV)infection in AIDS patients.Methods A total of 471 AIDS patients,including 173 with CMV infection and 298 without CMV infection were enrolled from Zhongnan Hospital of Wuhan University from June 2015 to August 2016.Multivariate Logistic regression was performed to analyze the risk factors for AIDS patients infected with CMV.Results Among 173 patients co-infected with CMV,103 (59.54%)were diagnosed as CMV viremia,70(40.46%)were CMV end-organ diseases (EOD),in which CMV pneumonia (n =33)and CMV retinitis (n =22)were the most frequent diseases.Univariate analysis showed that sexual transmission,low CD4 +T lymphocyte counts,first visit,tuberculosis,pneumococcal pneumonia (PCP), long hospital stay and septicemia were risk factors of cytomegalovirus infection among patients with AIDS (P <0.05).Multivariate Logistic regression analysis demonstrated that CD4 +T lymphocyte <50 cells/μL (OR =3.897,95%CI 2.354-6.453),concomitant tuberculosis(OR =4.619,95%CI 2.501 -8.529),PCP (OR =4.062,95%CI 2.345-7.038),sepsis (OR =2.553,95%CI 1 .098-5.936)were independent risk factors for CMV infection,while antiretroviral therapy (OR =0.559,95%CI 0.342-0.912)was a protective factor.Conclusions Hospitalized AIDS patients have a high incidence of CMV infection which has a tendency to induce multiple organ damage,and relevant risk factors should be avoid to accentuate disease as much as possible.

Objective To analyze the survival rate of HIV /AIDS patients receiving highly active antiretroviral therapy(HAART)since the implementation of the national Four Free and One Carepolicy against HIV in Hangzhou.Methods Clinical data of 2370 AIDS patients were collected from National AIDS Comprehensive Treatment Information System Treatment Library from 2004 to 2014.The data, including basic information,viral load,CD4 +T lymphocyte counts,starting time of treatment,WHO clinical stage,infection pathways and follow-up were respectively analyzed.Kaplan-Meier and Cox proportional hazards models were used to analyze the survival rate and the factors affecting survival.Results The total follow-up time was 3968.14 person years and 57 patients died in 2370 patients with a mortality rate of 1 .44 /100 person years (57 /3968.14).Kaplan-Meier method showed that the cumulative survival rates of the first,third and fifth year were 98.08%,96.20% and 95.24%,respectively.The overall mortality rate fell from 6.06 /100 person years in 2006 to 1 .44 /100 person years in 2014.The mortality rate of AIDS-related disease declined from 1 .10 /100 person years in 2009 to 0.90 /100 person years in 2014.Multivariate Cox regression analysis showed that the risk of death for patients with CD4 +T 200-349 cells/μL was 0.466 times(95%CI 0.246-0.882)as that for patients with CD4 +T cells <200 /μL.The risk of death was 3.408 times(95%CI 1 .365-8.506)in patients aged≥ 50 years,3.788 times(95%CI 1 .645-8.718)in patients aged 40 to <50 years,and 2.593 times(95%CI 1 .139-5.905)in patients aged 30 to 40 years as that in patients aged <30 years.The mortality risk for patients with baseline WHO stage Ⅲ and Ⅳ was 1 .960 times as patients with WHO stage Ⅰ and Ⅱ (95% CI 1 .117-3.439 ).Conclusions Patients with increased age,low CD4 +T counts and baseline WHO stage Ⅲ or Ⅳ are main risk factors affecting survival rate of HIV /AIDS patients,early antiviral therapy is the key for improving the survival rate of patients.

Objective To investigate the prevalence and characteristics of non-nucleoside reverse transcriptase inhibitors (NNRTIs)resistance-related gene mutations among the AIDS patients with virological suppression failure in Guangdong Province 2015.Methods Plasma samples from AIDS patients receiving highly active antiretroviral therapy for more than one year with viral loads > 1000 copies/mL from Guangdong province (except Shenzhen)were collected from January to December 2015.Total 612 HIV-1 gene fragments were amplified from plasma samples using self-developed lab method.Sub-genotypes were determined by phylogenetic tree according to the sequences,NNRTIs resistance-related mutations were determined in Stanford University HIV-1 Drug Resistance Database. The NNRTIs-resistance, the relationships of NNRTIs resistance-related mutations with baseline CD4 +T lymphocyte counts,transmission routes,antiviral regimens and HIV-1 genotypes were analyzed.SPSS 17.0 software was used to analyze the data.Results In 612 patients with virological suppression failure,the main NNRTIs resistance-related mutations were K103 (26.80%),Y181 (14.71 %),V179 (13.73%),G190 (11 .44%) and V106 (10.62%).The susceptibility rate of 310 patients (50.65%)to NNRTIs had changed,the highly resistant rate to nevirapine was 49.51 %,which was higher than that of efavirenz (43.14%),etravirine (5.56%) and rilpivirine (12.25%),respectively,and the differences were statistically significant (χ2 =5.00,296.3 and 198.0,all P <0.05).The incidence rate of drug resistance in patients with baseline CD4 +T lymphocyte counts >200 cells/μL was lower than that in those with baseline CD4 +T lymphocyte counts <200 cells/μL (χ2 =17.93,P <0.01 );the incidence rate of drug resistance was lower in intravenous drug abusers than that of sexually transmitted patients (χ2 =44.21 ,P <0.01 );while the incidence of drug resistance in patients receiving NVP-containing regimens was higher than that in those receiving EFV-containing regimens (χ2 =8.93,P <0.01 ),and the incidence rate was higher in patients with CRF01 _AE than that in those with CRF07_BC and CRF08 _BC (χ2 =8.46 and 8.47,P <0.01 ).Conclusions The results suggest that compliance education and follow-up should be strengthened in patients with high baseline CD4 +T lymphocyte counts and intravenous drug users,and patients with liver diseases should avoid using drugs containing NVP regimens.

In recent years,great progress has been made in treatment of patients with HCV infection with direct-acting antiviral agents (DAAs).Up to now,twelve kinds of oral DAAs and three kinds of combination regimens have been approved by the U.S.Food and Drug Administration and European Medicines Agency to treat chronic HCV infection.This article reviews the research progress of DAAs in treatment of hepatitis C,including the name of DAAs,drug targets,therapy regimen,clinical efficacy and adverse effects.

Ribonucleotide reductase ( RR ) is a rate-limiting enzyme, and it is responsible for reducing ribonucleotides to their corresponding deoxyribonucleotides , which are the building blocks required for DNA replication and repair .Recent studies have revealed that RR activity is associated with DNA replication in virus , and RR inhibitors have been used for clinical antiviral treatment .This paper reviews research progress on RR and its inhibitors , including the classification , structure and function of RR; the classification, mechanism and clinical application of RR inhibitors in antiviral therapy and the future prospects of RR inhibitors .