To identify the genotype and analyze the molecular characteristics of dengue virus strain SZ0524 isolated from serum samples of patients with early stage of dengue fever in Shenzhen in 2005 so as to explore its possible origin. The C6/36 cell line was cultivated with virus strain SZ0524 and its suspension was harvested. The type of isolated virus strain was determined by RT-semi-nested PCR and fluorescent PCR. E gene of isolated virus strain was amplified by RT-PCR and sequenced. Homology and phylogenetic tree of E gene of this dengue virus with the strains isolated from other areas were constructed. This SZ0524 strain was further identified by fluorescent PCR, and confirmed to be the type 4 virus after obtaining the 392bp band with type 4 specific primers. The homology of nucleotide sequence of E gene of SZ0524 strain with the standard type 4 dengue virus H241 strain were 99.7%, but the homology with the standard dengue virus 1,2,3 in the same fragment were 57.0%, 59.2% and 56.2% respectively. Analysis of the phylogenetic tree indicated that SZ0524 was more close to D4-73NIID and D4-61NIID strain, next to H241 strain, and they lied in the same branch of phylogenetic tree. The isolated dengue virus type 4 belonged to genotype Ⅰand the SZ0524 strain was proved to be dengue virus type 4 in the molecular level. Combined with epidemiology information, it is suggested that this case can be classified as an imported case and the SZ0524 strain may be transferred from the southeast asian region.

Objective To isolate Hantaviruses from reservoir animals captured in natural epidemic areas of hemorrhagic fever with renal syndrome(HFRS)and genotype isolated strains of Hantavirus in Shenzhen.Methods Infant Meriones unguiculatus and Vero-E6 cells were used in virus isolation and direct immunofluorescence assay was used for identifying viruses.The G1,G2 fragments of M segment and S segment were amplified with reverse transcription-nested-polymerase chain reaction(RT-nested-PCR)by using the Hantavirus genotype specific primers.The amplified genes were then sequenced,and subjected to homology and cladogram analysis.Results Two virus strains were isolated successfully and designated as SZ2082 and SZ2083 from Rattus norvegicus captured in Shenzhen and were identified as SEOV type by RT-nested-PCR.The nucleotide sequences of partial M and S segmentS of SZ2082 were consistent with SZ2083 completely.Compared with the G1 and G2 fragments of M gene of SEOV80-39 virus strain,the homologies of nucleotide among them were 96.7% and 95.0%,but the homology were 75.9% and 70.3% of the Hantaviruses strain with HTNV76-118 virus strain,respectively.The homology of S gene with SEOV80-39 and HTNV76-118 showed 95.7% and 69.7% at nucleotide level.The results were similar to that of M genome segment.SZ2082 and BjFT01,Beijing Rn,Guangl99,HN71-L were on the same branch and their homology reached up to 99.0%-99.7%.Conclusions Hantaviruses are isolated from Shenzhen for the first time and are classified as S2 subtype of Seoul virus.

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.

Objective Aims to reduce the hidden risks of laboratory biosafety,understand the status of biosafety laboratory record filing situations in Shenzhen,and also to provide scientific basis for further standardizing the management of biosafety laboratory in Shenzhen.Methods In 2017,75 laboratories in Shenzhen completed record filing were surveyed,method ologies adopted including application materials review,phone call consultation and communication,carrying out corrective ac tions based on feedback peer review suggestions and finally complete the record filing.Results The first/second level laborato ry of biosafety in shenzhen is mainly public medical institutions,followed by private hospitals.In 2017,the first three recordfiling LABS were Futian district,nanshan district and longgang district.According to the data analysis,lack of the second category of pathogenic microorganism laboratory activity project risk assessment report,and laboratory layout diagram function partition is not clear were two of the more prominent problems in the software and hardware of laboratory management respectively.Conclusions Basically,the overall record filing of Shenzhen biosafety laboratory is good,however,more measurements should be developed to deal with identified problems to further strengthen the standardized management of laboratory biosafety.

OBJECTIVETo understand the epidemiologic and etiologic characteristics of diarrheagenic Escherichia (E.) coli infections in Shenzhen.

METHODSStool samples were collected from acute diarrheal patients in four sentinel hospitals in Shenzhen and diarrheagenic E. coli strains were isolated and identified with multiplex real-time PCR. Serotyping and pulsed-field gel electrophoresis (PFGE) typing were conducted for the diarrheagenic E. coli isolates.

RESULTSA total of 74 diarrheagenic E. coli strains were isolated from 1 823 stool samples (4.06%). The patients were mainly young children aged <3 years and adults aged 20-39 years, and the infections mainly occurred during May-September of a year. Enterotoxigenic E. coli (ETEC) and enteropathognic E. coli (EPEC) were predominant (45.9% and 31.1%). Serogroups and PFGE patterns varied among the diarrheagenic E. coli isolates. However, serogroup O159 were predominant in ETEC and there were 5 clusters with ≥2 strains sharing same PFGE patterns.

CONCLUSIONSETEC and EPEC were predominant in diarrheagenic E. coli strains isolated from diarrheal patients in Shenzhen. Age and season specific characteristics of diarrheagenic E. coli infections were observed. The serotypes and PFGE patterns of diarrheagenic E. coli strains varied. Close attention should be paid to the possible ETEC outbreak.

Adult ; Child, Preschool ; China ; epidemiology ; Diarrhea ; epidemiology ; microbiology ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Enterotoxigenic Escherichia coli ; classification ; isolation & purification ; Escherichia coli Infections ; epidemiology ; Humans ; Real-Time Polymerase Chain Reaction ; Serotyping ; Young Adult