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Objective: To analyze the epidemiological and molecular characteristics of human brucellosis in Qinghai province from 2005 to 2019 and provide basic data for brucellosis prevention and control. Method: The data about human brucellosis in Qinghai from 2005 to 2019 were collected from the information system of China CDC to describe the spatial, population and time distributions of human brucellosis cases in Qinghai. The isolated strains were identified and typed with traditional methods, BCSP31-PCR, AMOS-PCR and multi-locus variablenumber tandem repeat (MLVA-16). Results: A total of 577 human brucellosis cases were reported in Qinghai from 2005 to 2019, the average prevalence rate was 0.07 per 100 000 person, there were statistic differences among different years. The disease occurred all the year around, but mainly during March-October. The 577 cases were distributed in 31 counties (cities/districts) from 6 autonomous prefectures (cities). The prevalence rats of five counties were high, i.e. Menyuan Hui autonomous county (22.88 % , 132/577), Tianjun county (10.57 % , 61/577)、Xining city (10.57 % , 61/577), Henan Mongol Autonomous County (10.51 % , 58/577) and Haiyan county (9.53 % , 55/577). Age of the cases ranged from 8 years to 82 years, and the male to female ratio of the cases was 1.8∶1 (374/203). The prevalence rate in herdsman (47.83 %, 276/577) was highest among different occupational populations. Ten isolates were all Brucella melitensis strains, belonging to biovar 3, and clustering analysis indicated that the 10 strains had 5 genotypes, in which 2 were distinct, the remaining 3 were same. MLVA-16 analysis indicated that the 10 strains had close relationship with 26 B. melitensis strains isolated in Qinghai previously. Conclusions: The prevalence of brucellosis increased in Qinghai in recent years, we should strengthen the population based brucellosis surveillance and reporting. MLVA-16 indicated the gene diversity of the Brucella strains, suggesting that MLVA-16 can be used for genetic diversity analysis and molecular epidemiology survey to improve brucellosis surveillance.

Objective: To understand the molecular characteristics and correlation among isolated strains of Brucella melitensis (BM) so as to improve the strategies on prevention and control of the disease in Jiangxi province. Methods: A total of 25 strains of BM isolated from human in 17 counties of Jiangxi province were analyzed by multiple locus variable-number tandem repeat analysis (MLVA) method. Results: A total of 25 strains of BM were classified into 24 independent genotypes with similarities between 67.00% and 100.00% and Simpson index between 0.000 and 0.773. There were 3 genotypes in MLVA8, including 60.00% (15/25) as 42 genotype, 32.00% (8/25) as 43 genotype, and 8.00% (2/25) as 63 genotype, respectively. There were 7 genotypes in MLVA11 identified, with 116 genotype and 125 genotype the main genotypes, accounting for 56.00% (14/25) of all the identified strains. Conclusions: Genes from all the 25 strains of BM that isolated from human being were with high genetic diversities, and various, genotypes. However, no obvious epidemiological correlation was noticed among these strains, indicating the complexity of the source of infection on Brucella in Jiangxi province.

Objective: To study the molecular-epidemiological characteristics of Brucella species isolated from different countries, using the multiple locus tandem-repeat (MLVA) analysis. Methods: Eleven variable-number tandem-repeat (VNTR) loci were selected. VNTR strains of Brucella isolated from 48 different countries in 1953-2013, were analyzed by using the BioNumerics software. Unweighted Paired Arithmetic Average method was used to cluster and draw phylogenetic tree as well as the minimum spannin. Results: The evolutionary relationship of Brucella phylogenetic tree was consistent with the classical biological typing method. However, the Brucella suis biovar 5 strains were different from the other Brucella suis biovars 1, 2, 3 and 4. Brucella ceti strains were divided into two parts and different from each other. Worldwide epidemics of brucellosis were emerged from 2005 to 2008 under the MLVA11 Orsay analysis. China has been a brucellosis-prone regions, with Brucella melitensis as the main epidemic Brucella species, followed by Brucella abortus. Brucella suis was mainly identified in the southern provinces, but Brucella canis was mainly found in dogs. No human cases were found. Conclusion: Molecular-epidemiological characteristics of the Brucella strains were related to factors as time, region and hosts of isolation, which are important to setting up prevention and control programs on brucellosis.

Objective: To better understand the clinical features of human adenovirus type 7 (hAdV7) pneumonia and to identify whether there is a variation in the genome of the strain (CHN/BeiJing/2018) isolated during the small-scale epidemic. Method: Forty-two patients were diagnosed with hAdV7 pneumonia between October 27th, 2017 and February 28th, 2018. They were all males with an average age of (21±2) years. Demographic and clinical data were reviewed and analyzed in detail. The nucleic acid of the epidemic strain was extracted from a bronchoalveolar lavage fluid sample. Whole genome sequencing (WGS) was then performed and sequences were compared with other hAdV7 strains distributed globally. Phylogenetic tree analysis was conducted based on whole genome sequences of the epidemic strain. Results: Thirty-eight cases with hAdV7 pneumonia presented with influenza-like symptoms (90.5%) at the onset and 36 cases developed fever (85.7%), followed by cough (97.6%), expectoration (90.5%) and chest pain (28.6%). Five cases presented with tonsillitis(11.9%) and 4 had transient hemoptysis (9.5%), while 3 patients reported dyspnea (7.1%). Moist rales were only heard in 3 patients (7.1%). Notably elevated creatine kinase (CK) concentrations were observed in 8 patients (19.1%), but all returned to normal after treatment. Four cases developed hypoxemia (9.5%), but none of them progressed to respiratory failure or acute respiratory distress syndrome (ARDS). Chest CT imaging showed bilateral patchy parenchymal opacities with a random distribution with or without consolidation. Ten patients were co-infected with influenza virus (23.8%), while 32 patients developed atypical pneumonia (76.2%). Genomic analysis revealed that the strain isolated during this epidemic was 99% similar to the known hAdV7 strains (19BOVLB/Volgograd/Rus/2014 and 0901HZ/ShX/CHN/2009). Phylogenetic tree analysis suggested that the strain was closely related to the hAdV7 strain isolated in Jingmen China in 2012. Conclusions: Cases with hAdV7 pneumonia were generally mild. Symptomatic treatment was sufficient for a favorable prognosis. A good genome stability of the hAdV7 strain was observed, indicating that hAdV7 could remain stable for a long period and cause continuing sporadic cases and clusters.

Forestomach papilloma and carcinoma, as well as liver lesion, were induced in mice by gavaging precursors of the new nitrosamine, MAMBNA (N-3-methylbutyl-N-1-methylacetonylnitrosamine) and NaNO2. The results were-similar to those in mice and rats fed on preformed MAMBNA compound. However, the induction of such tumors by in vivo formation of MAMBNA required longer time and much larger doses. Moreover, the lesions of epithelial hyperplasia in the urinary bladder, lymphoid tumor, intestinal carcinoma and interstitial-cell tumor of the testis also developed in some of the experimental animals. This may indicate that the intragastric synthesis of MAMBNA is less effective in the production of forestomach tumors in mice.