Objective: To learn the population,virus status and viral types of hantavirus（HV）hosts in Tiantai County of Zhejiang Province from 2011 to 2018,and to provide evidence for hemorrhagic fever with renal syndrome（HFRS）control. Methods: Rodents in Tiantai County were captured by night trapping method. After the species and age of rodents were identified,the composition of rodent species,dominant species and density of rodents were analyzed. The lungs and blood of rodents were sampled to detect the antigen and antibody of HV by immunofluorescence method. The HV antigen-positive lung samples were detected by RT-PCR with specific primers of HV S fragment,then HV was isolated and identified by inoculating Vero-E6 cells. Results: The average rodent density in Tiantai County from 2011 to 2018 was 4.44%. The rodent density in the field and residential areas were 4.94% and 2.23%,respectively. Ten species of rodents were identified,with Apodemus agrarius dominant in the field and Rattus norvegicus in the residential areas. Sixty-seven lung samples were HV antigen positive（4.13%）,one from Rattus norvegicus and the other sixty-six from Apodemus agrarius. Seventy-nine blood samples were HV antibody positive（4.86%）,all from Apodemus agrarius. Thirty-four HV antigen-positive lung samples were positive（50.75%）after RT-PCR amplification. Twenty-two strains of virus were isolated and all of them were from Apodemus agrarius,including twenty-one strains of Hantaan type（HTN）and one strain of Seoul type（SEO）. Conclusion In Tiantai County,Apodemus agrarius is the main source of HFRS infection;the main epidemic type of HV is HTN and SEO is first found in Apodemus agrarius.

Objective:To understand the in vitro antimicrobial resistance and resistance phenotypes profile of Streptococcus suis strains isolated from human in Zhejiang Province. Methods:The strains of sporadic Streptococcus suis infections were isolated during 2005 to 2021 in Zhejiang Province, and were subjected to antimicrobial resistance analysis using agar dilution method. Polymerase chain reaction (PCR) technology was also used to detect 70 resistance genes including tetracyclines, macrolides and aminoglycosides. Results:The results of antimicrobial resistance analysis showed that these strains were sensitive to eleven kinds of antimicrobial agents with a sensitivity rate ≥96.8%, including cefepime, cefotaxime, ceftriaxone, chloramphenicol, daptomycin, ertapenem, levofloxacin, linezolid, meropenem, penicillin and vancomycin. These strains were mainly resistant to tetracycline, clindamycin, azithromycin and erythromycin, especially resistant to tetracycline with a rate of 93.5%(29/31). Fourteen strains (45.2%) exhibited multidrug resistant patterns. The PCR analysis of 70 drug resistance genes showed that 14(20.0%) different resistance genes were detected. The highest detection rate of resistant genes came from tetracycline, including tet ( O) gene (58.1%, 18/31), tet ( M) gene (48.4%, 15/31), tet ( 40) gene (35.5%, 11/31), followed by ermB gene (41.9%, 13/31) in the class of macrolide. Fourteen strains (45.2%) with more than three drug resistance genes were detected, of which eight strains (25.8%) detected 10 drug resistance genes. The analysis of antibiotic resistance and resistance phenotypes profile showed that tet ( M)+ ST7 accounted for 35.5%(11/31), tet( O)+ tet( 40)+ ermB+ mef( A)+ mef( A/ E)+ msrD+ Ant( 6)- Ⅰb+ aph( 3′)- Ⅲa+ aadB+ sat4+ ST7 accounted for 25.8%(8/31). Conclusions:The antimicrobial resistance and resistance phenotypes profile of sporadic Streptococcus suis strains isolated from human in Zhejiang Province are endemic, with mainly two types of characteristic genetic cloning of drug resistance genes.

Objective: By investigating the genotype and evolutionary variation of hantavirus (HV) in Tiantai county, a national surveillance site for hemorrhagic fever with renal syndrome (HFRS) was set in Zhejiang province, from 2011 to 2018, to reveal the molecular epidemiological characteristics of hantavirus (HV) in Tiantai. Methods: Total RNA was extracted from ultrasound treated HV antigen- positive rat lung samples in Tiantai from 2011 to 2018. After cDNA was prepared, nested PCR was used to amplify partial sequence of M fragments by using specific primers of HV. The sequences of HV in Tiantai from 2011 to 2018 were compared with other known HV sequences in order to identify the genotype and analyze the evolution and variation of the virus. Results: In 67 HV antigen-positive lung specimens, 31 were positive in nested PCR amplification with type-specific primers, including 30 Hantaan virus (HTNV) positive samples, 1 Seoul virus (SEOV) positive sample, and all the 31 samples were from Apodemus agrarius. The phylogenetic tree based on partial M segment was divided into monophyletic group, 30 strains were distributed in HTNV group and 1 was in SEOV group. The HTNV strain Tiantai T2018-130 was independently in one branch, sharing 84.8%-87.9% homology with other strains both at home and abroad, including 29 strains in HTNV group in Tiantai. The other 29 HTNV strains in Tiantai showed closer relationship. The SEOV strain T2016-31 from Apodemus agrarius showed closer relationship with previous strains of SEOV, Tiantai ZT71, ZT10 and Z37 strains of Wenzhou, Zhejiang province. Conclusions HTNV, the main genotype of HV in Tiantai of Zhejiang province, showed obvious geographic clustering, but the strain T2018-130 was distinct from the others in Tiantai. Meanwhile, by sequence analysis, we confirmed that The SEOV strain T2016-31 existed in in Apodemus agrarius, indicating there was a phenomenon of "spillover" between virus and host in SEOV evolution.