ABSTRACT
Objective:To investigate the epidemiological characteristics of dengue fever and genotyping of the epidemic strains of dengue virus in Shenzhen City in 2018.Methods:Descriptive epidemiological analysis was used to analyze dengue fever prevalence in Shenzhen City in 2018. Blood samples of patients with dengue fever were collected. The colloidal gold immunochromatography was used to detect serum specific IgM and IgG antibodies, and real-time fluorescence quantitative polymerase chain reaction (PCR) was used to detect viral nucleic acids and to identify genotypes. The E gene sequence of isolated virus strain was amplified by reverse transcription PCR. Homology comparison and phylogenetic tree of dengue fever epidemic strains in different countries and regions were conducted. Results:A total of 234 cases of dengue fever were reported in Shenzhen City from January 1 to December 31, 2018. The incidence rate was 1.87/100 000. There were 144 (61.54%) local patients and 90 (38.46%) imported patients, who were mainly from Southeast Asia and surrounding cities. Two hundred and two (86.32%) cases were reported during the epidemic peak period from August to November of the year. The patients mainly aged 20 to 50 years old (195 cases, 83.33%). Dengue virus type (DENV)-1 accounted for 86.01%(166/193), DENV-2 accounted for 10.36%(20/193), DENV-3 accounted for 2.59%(5/193), and DENV-4 accounted for 1.04%(2/193). The local cases were all infected with DENV-1. The homologies of nucleotide sequence and the deduced amino acid sequence of E gene of 24 DENV-1 strains with HAWAII45 strain were 93.0% to 94.6% and 96.6% to 97.2%, respectively. The phylogenetic tree of DENV-1 strains revealed that 23 strains belonged to genotypeⅠ, and one strain belonged to genotype Ⅳ which was the first reported imported cases in Shenzhen City. The homologies of nucleotide sequence and the deduced amino acid sequence of E gene of six DENV-2 strains with NGC strain were 93.1%to 93.9% and 97.0% to 97.8%, respectively. The phylogenetic tree of DENV-2 strains showed that two strains belonged to genotype Cosmopolitan and four strains belonged to genotype Asian Ⅰ, which were first reported in Shenzhen City. Conclusions:The epidemic of dengue fever in Shenzhen City in 2018 has the characteristics of coexistence of local and imported transmission. The main epidemic genotype is DENV-1. It infers that the major virus strains may be imported from Southeast Asia countries and surrounding cities. Therefore, attention should be paid to the epidemic trend of local dengue fever.
ABSTRACT
Objective@#To investigate the genetic characteristics of VP1 genes carried by coxsackievirus A16 strains isolated from cases of hand foot and mouth disease (HFMD) in Shenzhen during 2016 to 2017.@*Methods@#Fecal and anal swab specimens were collected from patients with mild HFMD in four sentinel hospitals and the Institute of Pathogen Biology, Shenzhen Center for Disease Control and Prevention, China during 2016 to 2017. All specimens were tested for CVA16 viral RNA using real-time RT-PCR. The VP1 genes of 51 randomly selected CVA16 strains were amplified by RT-PCR and then sequenced using TaKaRa Biomedical Technology (Dalian). Bioinformatics software, including Mega6.02, BioEdit and DNAStar, was used for comparison and analysis of the VP1 genes.@*Results@#CVA16 strains in Shenzhen during 2016 to 2017 mainly belonged to B1a and B1b subtypes as well as an emerging subtype B3. The epidemic of B1b subtype was found in both 2016 (28 strains) and 2017 (19 strains), while the B1a subtype (two strains) was only detected in 2017. Two B3 subtype strains were detected in 2017. The strains of B1b subtype were closely related to the strains isolated in Shanghai (JQ314149), Wenzhou (KP289416) and Beijing (KU254598), while the B1a subtype strains were closely related to the strains isolated in Kunming (JQ316639) and Tailand (GQ184139). The B3 subtype strain was an emerging CVA16 epidemic strain in mainland China. Further comparison of the CVA16 epidemic strains in Shenzhen area during 2016 to 2017 with the CVA16 strains causing severe neurological symptoms showed that two amino acid mutations (S14N and M23L) were found in VP1 protein.@*Conclusions@#The epidemic strains of CVA16 were B1b subtype in Shenzhen area in 2016. However, B1a, B1b and the emerging B3 subtype strains were prevalent in 2017. Compared with the CVA16 strains causing severe neurological symptoms, the CVA16 strains circulating in Shenzhen during 2016 to 2017 carried two amino acid mutations inVP1 protein.
ABSTRACT
Objective To investigate the genetic characteristics of VP1 genes carried by coxsack-ievirus A16 strains isolated from cases of hand foot and mouth disease ( HFMD) in Shenzhen during 2016 to 2017. Methods Fecal and anal swab specimens were collected from patients with mild HFMD in four senti-nel hospitals and the Institute of Pathogen Biology, Shenzhen Center for Disease Control and Prevention, China during 2016 to 2017. All specimens were tested for CVA16 viral RNA using real-time RT-PCR. The VP1 genes of 51 randomly selected CVA16 strains were amplified by RT-PCR and then sequenced using TaKaRa Biomedical Technology ( Dalian). Bioinformatics software, including Mega6. 02, BioEdit and DNAStar, was used for comparison and analysis of the VP1 genes. Results CVA16 strains in Shenzhen during 2016 to 2017 mainly belonged to B1a and B1b subtypes as well as an emerging subtype B3. The epi-demic of B1b subtype was found in both 2016 (28 strains) and 2017 (19 strains), while the B1a subtype ( two strains) was only detected in 2017. Two B3 subtype strains were detected in 2017. The strains of B1b subtype were closely related to the strains isolated in Shanghai ( JQ314149 ) , Wenzhou ( KP289416 ) and Beijing (KU254598), while the B1a subtype strains were closely related to the strains isolated in Kunming (JQ316639) and Tailand (GQ184139). The B3 subtype strain was an emerging CVA16 epidemic strain in mainland China. Further comparison of the CVA16 epidemic strains in Shenzhen area during 2016 to 2017 with the CVA16 strains causing severe neurological symptoms showed that two amino acid mutations ( S14N and M23L) were found in VP1 protein. Conclusions The epidemic strains of CVA16 were B1b subtype in Shenzhen area in 2016. However, B1a, B1b and the emerging B3 subtype strains were prevalent in 2017. Compared with the CVA16 strains causing severe neurological symptoms, the CVA16 strains circulating in Shenzhen during 2016 to 2017 carried two amino acid mutations inVP1 protein.
ABSTRACT
Objective To analyze the genetic characteristics of VP1-VP4 genes carried by cox-sackievirus A6 (CVA6) strains isolated from severe cases of hand, foot, and mouth disease (HFMD) in Shenzhen during 2012 to 2015. -ethods The VP1-VP4 genes of CVA6 strains isolated from severe HFMD cases in Shenzhen during 2012 to 2015 were amplified and sequenced. Phylogenetic analysis was performed to analyze the VP1-VP4 genes of CVA6 isolates and sequences downloaded from GenBank by using DNASTAR6. 0 and MEGA6. 02 software packages. Results Four cases of severe HFMD were caused by CVA6 in Shenzhen during 2012 to 2015. All of the patients had the symptom of fever, skin rash and aseptic encephalitis. The CVA6 strain causing severe HFMD in 2013 shared 98. 8％-98. 9％ homology in nucleotide sequences and 99. 3％-99. 8％ in amino acid sequences with the strains isolated in 2012. Two amino acid mutations were found in the CVA6 strain isolated in 2013, which were G73E in VP2 region and S13G in VP1 region. However, the CVA6 strain isolated in 2015 only shared 95. 0％ homology in nucleotide sequences and 99. 3％ homology in amino acid sequences with the strain isolated in 2013. Six amino acid mutations were identified including E73G in VP2 region and T5A, S27N, A30V, N137S and V242I in VP1 region. The phylogenetic analysis revealed that the four CVA6 strains belong to D3 sub-genotype. The CVA6 strains causing severe cases in 2012 had the nearest genetic relationship with the strain isolated in Changsha in 2012 (KJ156349). The CVA6 strain isolated in Shenzhen in 2013 had the nearest genetic relationship with the strain isolated in Shanghai in 2013 (KJ612513). The Shenzhen CVA6 isolate in 2015 showed high similarity to Weifang CVA6 isolate in 2014 (KX752785). Conclusions All CVA6 strains causing severe HFMD ca-ses in Shenzhen during 2012 to 2015 belongs to D3 sub-genotype. Mutations of S27N and A30V in the VP1 region of the CVA6 isolate in 2015 are located in the B cell epitopes. In addition, the VP1-V242I mutation in the CVA6 strain isolated in 2015 is located in the binding site of PSGL-1 receptor. These mutations may affect the binding of CVA6 strains to the cellular receptors and their infectivity to people.
ABSTRACT
Objective@#To study the epidemiology and the etiology characteristics of first imported severe fever with thrombocytopenia syndrome (SFTS) case reported in Shenzhen city in 2017.@*Methods@#Data on descriptive epidemiology was collected to study the characteristics to the epidemic. The serum sample collected from the suspect SFTS case was detected for IgM, IgG by ELISA and severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) nucleic acid by real-time RT-PCR. The samples were further inoculated in Vero cell for virus isolation. The partial fragements of L and S gene were amplified by RT-PCR and sequenced to construct homology comparison and phylogenetic tree with the strains isolated from other areas.@*Results@#The case was laboratory confirmed imported SFTS case in Shenzhen on May 2017. IgM antibody and RNA of SFTSV were detected in the serum sample. SFTSV named GDSZ01/2017/China was successfully isolated from the serum sample. The high nucleotide homology of L and S genome segments were found at 95.3%-98.2% and 93.8%-98.8% with other representative strains from the popular provinces, respectively. The phylogenetic tree indicated that GDSZ01 was most close to SDTA_3 strain, next to strains in Hubei procince. The isolated SFTSV belonged to genotype C3 with HB29, HB154.@*Conclusions@#The virological, serological and molecular features showed that the imported case of SFTS in 2017 was caused by SFTSV C3 genotype.
ABSTRACT
Objective To investigate the epidemiological characteristics of dengue fever in Shenz-hen city in 2014 and to analyze the evolutional characteristics of the epidemic dengue virus(DENV)strains in order to provide scientific guidelines for the prevention and control of dengue fever. Methods Descrip-tive epidemiological analysis was used to analyze the prevalence of dengue fever in Shenzhen city in 2014. Immunochromatography and real-time PCR were performed to detect the specific antibodies(IgM and IgG) and DENV nucleic acids in serum samples collected from suspected cases of dengue fever. Serum samples collected from the patients at early stage of dengue fever were used to infect the C6 / 36 cell line for further isolation of DENV strains. The types of isolated DENV strains were determined by using real-time PCR. E genes of the isolated DENV strains were amplified by RT-PCR and then sequenced. DNAStar and Clustslx (1. 83)softwares were used to analyze the homology between DENV strains isolated in Shenzhen and other areas. A phylogenetic tree based on the sequences of E genes of Shenzhen strains and other sequences of DENV reference strains downloaded from GenBank was constructed for further analysis. Results A total of 454 cases of dengue fever were reported in Shenzhen in 2014 with a male to female ratio of 1. 43 ∶ 1. Local patients accounted for 76. 21% and the rest 23. 79% were imported cases mainly from Southeast Asian and surrounding cities. There were 441 cases reported from September to November,accounting for 97. 14% of all reported cases. Most of the infected subjects were aged 20 to 50,accounting for 76. 73% . Of the 270 samples positive for DENV nucleic acids,strains of DENV-1,DENV-2,DENV-3 and DENV-4 accounted for 87. 41% ,8. 89% ,0. 37% and 2. 22% ,respectively. The phylogenetic tree analysis revealed that the DENV-1 strains belonged to two genotypes,which were genotypeⅠ and genotype Ⅴ. The DENV strains of genotypeⅠ were highly similar to the epidemic strain isolated in Shenzhen in 2010 and the genotype Ⅴstrains were first reported in Shenzhen. The homology analysis of the nucleotides of E genes showed that mi-nor differences in the nucleotide sequences were found between DENV-2 strains. All of the DENV-2 strains belonged to the genotype Ⅳ as indicated by the phylogenic tree. Conclusion There were 454 cases of den-gue fever(including both local and imported cases)reported in Shenzhen city in 2014,reaching an all-time high. DENV-1 was the predominant pathogen in combination with an increased infection of DENV-2. This study indicated that the prevalent DENV strains might be imported from Southeast countries and neighboring cities. Further researches should be conducted to analyze whether dengue fever is endemic in Shenzhen City.
ABSTRACT
Objective To analyze the VP1-VP4 genetic region of enterovirus 71 ( EV71 ) strains isolated from children with severe or mild hand, foot and mouth disease ( HFMD) in Shenzhen in 2012. Methods EV71 strains were isolated from five children with mild HFMD and five children with severe HFMD in Shenzhen in 2012.Reverse transcription-polymerase chain reaction ( RT-PCR) method was used to amplify the sequence of VP1-VP4 genes of EV71 strains.The sequences of the amplified products were analyzed by comparing with those of the EV71 reference strains ( A, B and C genotypes) published in Gen-Bank using nucleotide alignment, amino acid alignment and phylogenetic tree analysis.Results The homo-geneity between the EV71 strains isolated from severe and mild cases was 95.1%-98.2% in nucleotides and 99.2%-100% in amino acids.The VP1-VP4 nucleotide sequences of 5 strains isolated from severe cases and 5 strains from mild cases in Shenzhen shared 87.9%-97.8% homologies in nucleotides and 97.3%-99.9% homologies in amino acids with the genotype C EV71 reference strain.The EV71 strains isolated from children in Shenzhen were highly similar with the EV71 strain (FJ439769) isolated in Fuyang in 2008 and the one isolated in Jingdezhen in 2011 (JQ806378, C4a subtype) in nucleotide sequences.Mutations at the residue 31 in the VP1 region ( N→D ) were detected in 3 strains isolated from children with severe HFMD.Conclusion All of the 10 EV71 strains isolated in Shenzhen in 2012 belonged to the sub-genotype C4a.The mutation ( aa31 N→D) in the VP1 region of EV71 might be related to the different clinical mani-festations of HFMD cases in Shenzhen area.
ABSTRACT
Objective To investigate the effect of recombinant human interferon α-2b on influenza virus in vitro.Methods Influenza A virus subtype H1N1 and influenza B/Y virus were inoculated into Vero cells and different concentrations of interferon α-2b and oseltamivir were added.Numbers of virus plaques were observed and calculated,and quantitative RT-PCR were used to assess the inhibitory effect of interferon α-2b and oseltamivir in vitro.The nuclear export of viral ribonucleoprotein (RNP) complexes were monitored under fluorescence microscope.Results Virus plaque test showed that influenza A viruses subtype H1N1 were significantly inhibited when 10 μg/μL interferon α-2b and 10 μg/μL oseltamivir were added,and the numbers of plaques were 7.5 × 108 and 15 × 108 PFU/mL,respectively;the inhibitory effect of oseltamivir was better than that of interferon α-2b.Influenza B/Y viruses were also inhibited when 10 μg/μL interferon α-2b and 10 μg/μL oseltamivir were added,and the numbers of plaques were 1.1 × 108 and 1.5 × 108 PFU/mL,respectively.Quantitative RT-PCR results showed that the cycle threshold (CT) values of influenza A virus subtype H1N1 and influenza B/Y virus were much higher when 10 μmol/L interferon α-2b and 10 μmol/L oseltamivir were added.CT values of influenza A virus subtype H1N1 were 16,26 and 35 before and after inferferon α-2b and oseltamivir were added.CT values of influenza B/Y virus were 18,27 and 31 before and after interferon α-2b and oseltamivir were added.Reduction in the nuclear export of viral RNP in influenza A virus subtype H1N1-infected Vero cells was also observed when 10 μmol/L interferon α-2b were added.Conclusion Interferon α-2b has significantly inhibitory effect on both influenza A virus subtype H1N1 and influenza B/Y virus in vitro.
ABSTRACT
Objective To analyze the genetic characteristics and molecular variation of human rhi-novirus strains isolated in Shenzhen.Methods RNA samples were extracted from nasopharyngeal swab samples collected from influenza-like subjects in Shenzhen and analyzed by fluorescent RT-PCR.The VP4-VP2 and VP1 gene regions of human rhinovirus strains were amplified by nested RT-PCR.Clustal W and MEGA programs were used to evaluate molecular variation of the human rhinovirus strains.Results Both human rhinovirus A and B were prevalent in Shenzhen during 2012.Human rhinoviruses A was the predomi-nant pathogen, including subtypes A47, A31, A90, A18 and so on.Two recombinant strains of human rhi-noviruses A47 and A31 were detected.The mutations scattered on the VP1 protein and varied in different subtypes.The receptor binding sites ( loop BC, DE and HI) in different subtypes showed polymorphism. Five out of twenty-five drug sensitivity sites ( I121V, L123M, V167I, Y189H and H259G) showed muta-tion.Conclusion Multiple subtypes of human rhinovirus were prevalent in Shenzhen and were in a state of constant recombination and variation.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development.</p><p><b>METHODS</b>Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed.</p><p><b>RESULTS</b>In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02).</p><p><b>CONCLUSION</b>ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.</p>
Subject(s)
Humans , Biomarkers , Chemistry , Chorionic Gonadotropin , Chemistry , Culture Media , Chemistry , Embryo Transfer , Embryonic Development , Fertilization in VitroABSTRACT
<p><b>OBJECTIVE</b>To explore the correlation of human chorionic gonadotrophin (hCG) level in the follicular fluid on oocyte retrieval day with the number of oocytes retrieved, maturation rate, embryonic development, and pregnancy outcome in controlled ovarian stimulation cycles.</p><p><b>METHODS</b>The data of 311 IVF/ICSI-ET cycles from 2012 to 2013 was analyzed and stratified according to hCG level in follicular fluid on oocyte retrieval day (<7 nmol/L, 7-14 nmol/L, 14-21 nmol/L, and >21 nmol/L) determined with chemiluminescence method. The number of oocytes retrieved, oocyte maturation rate, fertilization rate, cleavage rate, available embryo rate and pregnancy rate were compared between the groups.</p><p><b>RESULTS</b>In the IVF/ICSI-ET cycles, the cycles with hCG level of 14-21 nmol/L in the follicular fluid on the day of oocyte retrieval had significantly higher oocyte maturation rate and fertilization rate than those in the other 3 groups (P<0.05), but the number of oocytes retrieved, cleavage rate, available embryo rate and pregnancy rate, though slightly higher, showed no significant difference from the other 3 groups (P>0.05). In the group with hCG level >21 nmol/L, the oocyte maturation rate and fertilization rate were significantly lower than those in the other 3 groups (P<0.05), and the available embryo rate and pregnancy rate were slightly lower without significant differences from the other 3 groups (P<0.05).</p><p><b>CONCLUSION</b>Follicular fluid hCG level on the day of oocyte retrieval is associated with oocyte maturation, fertilization, embryonic development potential, and IVF outcome. An excessively high follicular fluid hCG level on the day of oocyte retrieval may have negative effects on oocyte maturation and embryo development.</p>
Subject(s)
Adult , Female , Humans , Pregnancy , Young Adult , Chorionic Gonadotropin , Chemistry , Embryonic Development , Fertilization in Vitro , Follicular Fluid , Chemistry , Oocyte Retrieval , Oocytes , PhysiologyABSTRACT
Objective To study the epidemic pattern and molecular variation of respiratory syncy-tial virus ( RSV) strains isolated in Shenzhen from year 2012 to 2013.Methods The clinical samples iso-lated from patients with influenza-like illness were analyzed by fluorescent RT-PCR to screen RSV positive strains.The C-terminal variable regions of genes encoding G proteins were amplified by nested RT-PCR. Molecular variation was analyzed by using Clustal W and MEGA softwares.Results RSV strains were wide-ly prevalent in Shenzhen from 2012 to 2013.Two epidemic peaks usually occurred in spring and summer/au-tumn of each year.The RSV isolates were subtyped into group A belonging to genotype NA1 and group B be-longing to genotype BAⅨ.Most of the mutations scattered at the C-terminal region of G protein.A few mu-tations caused the disappearance of certain glycosylation sites.A novel recombinant virus strain containing 24 inserted amino acids was identified in 2013, which was likely to be introduced into our country from abroad. Conclusion RSV strains were widely and continuously prevalent in Shenzhen, characterized by constant evolution and variation.
ABSTRACT
Objective The aim of this prospective study was to evaluate the changes in the ovarian reverse after myomectomy based on serum anti-Mullerian Hormone (AMH) levels. Methods This is a prospective longitudinal observational study. Serum AMH levels were measured at the baseline and 2 day , 3months after myomectomy in 35 women aging from 36 to 45years.Follicle stimulate hormone(FSH) and luteal hormone(LH) were measured at the same time. 35 women of the same age with fibroid who did not undergo operation were selected as control group. Result (1)AMH level is (1.54 ± 0.95)ng/mL,(1.18 ± 0.77)ng/mL,(1.50 ± 0.58 )ng/mL at 0 day, 2 days and 3 months after operation. AMH level decreased significantly at 2 days after operation (P 0.05).(2) Significant differences in the serial change of AMH levels existed at each time point between myomectomy group and control group (P <0.05). No significant differences in FSH or LH levels existed at each time point. Conclusion AMH is may be superior to FSH or LH in evaluating the changing of ovarian reverse. The study suggests that myomectomy affect the ovarian function for up to 3 months post-operatively , and hemorrhage during and after operation may decrease serum AMH levels.
ABSTRACT
Objective To evaluate the value of the new ovarian function marker serum anti-Mullerian hormone (AMH)and to clarify the effect of hysterectomy on the ovarian function of the younger women.Methods The serum AMH,follicle stimulating hormone (FSH)and luteinizing hormone (LH)levels in 35 women suffered uterus benign lesion aged 36-45 years and 35 women suffered hysteromyoma without operation were measured at different time.And the ovarian arterial blood flow resistance index (RI ) was measured by Doppler ultrasound. Results Compred with before operation, the serum AMH levels of the patients in hysterectomy group 2 d and 3 months after operation were significantly decreased (P0.05).Conclusion Hysterectomy can affect the ovarian function,and the serum AMH level 3 months after operation is decreased and the ovarian arterial blood flow RI is increased.AMH is superior to FSH or LH in evaluating the changes of ovarian function.
ABSTRACT
Objective To determine the pathogen of a local dengue fever outbreak in Shenzhen city in 2010,and to analyze the molecular characteristics of the epidemic dengue virus strain as well as explore the possible origin.Methods The serum samples collected from the suspect dengue fever cases were detected for IgM, IgG by enzyme-linked immunosorbent assay ( ELISA ),immunochromatography and dengue virus nucleic acid by real-time polymerase chain reaction (PCR).Serum samples from patients with early stage dengue fever were used to isolate virus with C6/36 and BHK-21 cell lines.The type of isolated virus strain was determined by RT-semi-nested-PCR and realtime PCR.E gene of isolated virus strain was amplified by RT-PCR and sequenced.Homology and phylogenetic tree of E gene of Shenzhen dengue virus with the strains isolated from other areas were constructed.Results IgM,IgG and RNA of type 1 dengue virus were detected in serum samples from dengue fever suspected patients.Type 1 dengue virus named DEV1-SZ1029 was successfully isolated from the serum sample.The homology of nucleotide sequence of E gene of SZ1029 strain with standard type 1 dengue virus HAWAII 45,Fj231/04,GD14/97 and GD05/99 were 94.8％,99.6％,97.7％ and 98.5 ％,respectively.The phylogenetic tree indicated that SZ1029 had the greatest similarity with the D1/Malaysia/36000/05 strain,SG(EHI)DED142808 strain and Fj231/04 strain and they lied in the same branch of the phylogenetic tree.The isolated dengue virus type 1 belonged to genetype Ⅰ with GZ/80,Taiwan87,All patients lived in a certain construction site in Shenzhen and had no recent travel history outside the area in one month before infection.Conclusions The virological,serological and molecular features all identify that the local dengue fever outbreak in Shenzhen in 2010 is caused by type 1 dengue virus and SZ1029 strain may be transferred from Southeast Asian region,and there may be a plague focus in Shenzhen.
ABSTRACT
Objective To detect infection of Angiostrongylus cantonensis and examine effection of treatment to prepare monoclonal antibodies(McAbs). Methods Six-week-old BALB/c mice were imrnunized by the intraperitoneal injection of e/s antigens of Angiostrongylus cantonensis. Fusion of splecn cells from immunized mice with prepared SP2/0-Ag14 myeloma cells was performed in RPMI 1640. Fused cells were suspended in RPMI 1640 containing 1% HAT and 20% fetal calf serum and dispensed into 96-well cell culture plates. The supernatants of clones were screened by ELISA with sera of patients of angiostrongyliasis.Distribution of cohere antigen of 12D5 and 21B7 monoclonal antibodies was analyzed with immunohistochemistry. Two McAbs ( 12D5 and 21B7) were applied to detect the circulating antigen (CAg) in the sera of rats infected with A. cantonensis and angiostrongyliasis patients respectively by double antibody sandwich ELISA.Results 12D5 McAb was identified as IgG1 and 21 B7 McAb was IgM. Western blot result showed two McAbs could used to identified 55 × 103 protein of adult worms of A. cantonensis. Cohere antigen of 12D5 and 21B7 monoclonal antibodies were distributed on intestine surface of A. cantonensis. The detection rates of CAg in the sera of infected rats 100% (48/48), the detection rates of CAg in the sera of angiostrongyliasis patients was 100% (32/32). No cross-reaction to sera of patients with other infection of parasites, such as clonochiasis, fasiolopsiasis, ancylostomiasis, trichinosis, anisakiasis as well as schsitosomiasis, and health srea did not reacted with 12D5 and 21B7 McAbs,and detaction rate of antibody of angiostrongyliasis patients only reached 75% (24/32) with antigen of A. cantonensis. Conclusion Cohere antigen of 12D5 and 21B7monoclonal antibodies were antigens of enteric epithelium. Sandwich ELISA with 12D5 and 21B7 McAbs showed high specificity act as detecting CAg of A. cantonensis in sera of infection animal and patients. It is apparent that Sandwich ELISA with 12D5 and 21 B7 is not only rapid and simple without requirement of special instrument, but also rather sensitive and specific for the detection of current infection with A. cantonensis.
ABSTRACT
Objective To compare and contrast the gene characteristic correspondence of hantaviruses(HV) carried by rats in natural epidemic areas of hemorrhagic fever with renal syndrome(HFRS) and infected among HFRS patients in Shenzhen,provide a reasonable scientific basis for controlling of HFRS.Methods We collected the patients serum specimens in acute stage and lung tissues samples of rats.ElISA and direct immunofluorescence were applied to screen the positive samples,respectively.The partial G2 fragments of M segment and S segment were amplified from the representative patients' serum positivesamples and lung tissues positive samples in different areas with reverse transcription-nested-polymerase chain reaction(RT-nested PCR) by the hantaviruses genotype specific primers.The amplified genes were then sequenced,and subjected to genotyping and homology analysis with other known hantaviruses.Results Four hundred and seventy-two rats were trapped in the main epidemic areas,and Hantavirus specific-antigens in lung tissues samples were identified in 47 out of the 472 by direct immunofluorescence.Twelve partial M and S segments were amplified from 60 patients serum specimens positive with specific IgM antibodies against hantavirus with ELISA by RT-nested PCR.The homology of M and S genome segments among 16 strains of Hantaviruses showed more than 95% and 96.5% at nucleotide level,respectively.And the deduced amino acid sequences homology was 98.0% -100% and 98.4%-100%,respectively.The genotype of hantavirus carried by rats and infected among patients were identified to the same subtype-SEO S2.Conclusion The genotype of Hantavirus carried by rats and infected among patients in Shenzhen all belongs to S2 SEOV.The nucleotide homology of SEO type of Hantavirus in the same or nearby areas is higher and the viruses are highly conserved.
ABSTRACT
To identify the gene differentially expressed in female Anopheles anthropophagus and to analyze its gene sequence, this gene amplified by PCR was identified by real-time PCR and its cDNA was then amplified with rapid amplification of cDNA ends (RACE) technology. It was found that the expression ratio of the female differentially expressed gene in female and male mosquitoes was 267.49 according to the formula F=2~(-⊿⊿CT).The size of mRNA of the gene was 364 bp, and the amino acid sequence deduced from the open reading frame (ORF) was found to be similar to the sequence of tectin protein of Culex quinquefasciatus and proteins of other species. The mRNA sequence of this gene was submitted to NCBI with a accession number of FJ907236. This gene may provide a foundation for further studies on the biological functions of mosquitoes.
ABSTRACT
Objective Apoptosis or programmed cell death(PCD) has been studied extensively in multicellular organisms,however,very little is known about the molecular mechanisms by which apoptosis occurs in unicellular protozoan parasites.The aim of this study is to characterize the apoptosis or PCD of Trichomonas vaginalis induced by metronidazole (MTZ).Methods T. Vaginalis strain cultures were treated with various concentrations of MTZ and the number of viable cells were determined at different time intervals.The genomic DNA of MTZ treated T. Vaginalis was extracted and DNA fragmentation was analyzed.TUNEL assay was carried out to detect the endonuclease activity in T. Vaginalis after MTZ treatment.Flow cytometric analysis was used to analyse the phosphatidylserine (PS) exposure of T. Vaginalis.Results Metronidazole (MTZ) induced an apoptotic-like cell death in T. Vaginalis.This apoptotic-like cell death was demonstrated by cell shrinkage,phosphatidylserine exposure,and nuclear chromatin condensation.However, no oligonucleosmal DNA laddering was detected.Conclusion The regulatory pathway of apoptotic cell death in T. Vaginalis may be different from multicellular organisms.The determination of protozoan apoptotic pathways leading to cell death might ultimately allow the identification of new therapeutic targets.
ABSTRACT
Objective Rab11 GTPases play an essential role in regulating membrane trafficking pathways in eukaryotic cells. Nonetheless, there has been little work done on characterizing the transport machinery of Trichomonas. The aim of this study is to clone and characterize a Rab11 gene of Trichomonas vaginalis.Methods A cDNA expression library was constructed with T. vaginalis total RNA. A cDNA clone, which showed a high degree of homology with Rab proteins of different species, was isolated and sequenced. Sequence analysis was performed using BLASTP, RPS-BLAST and ClustalW programs. The genomic DNA corresponding to the cDNA sequence was amplified using PCR techniques and following by sequencing. Results cDNA with a length of 710 base pairs and an open reading frame of 636 bp was obtained. The deduced amino acid sequence from the open reading frame was found to possess 211 residuals. Sequence analysis demonstrated that this cDNA clone was homologous to the Rab11 subfamily of different species (60% identity and 79% similarity with Arabidopsis thaliana Rab11c, 58% identity and 78% similarity with human Rab11b), and that the amino acid sequence contains all the well known conserved sequence elements of Rab family. Specific Rab motifs were also detected in the deduced amino acid sequence. Phylogenetic analysis showed that its closest homologues are Rab11 proteins from other species. Sequencing of the PCR product of genomic DNA revealed that the genomic DNA sequence encompassing the putative 5'-ATG and 3'-stop codon is identical to the cDNA sequence.Conclusion A cDNA clone corresponding to the T. vaginalis Rab11 gene was obtained.The function of this gene in regulating membrane trafficking pathways of the parasitic protist is still under investigation.