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Euonymus bungeanus plants exhibiting symptoms of abnormal branches, small leaves and phyllody, which is indicative of E. bungeanus witches' broom (Eb WB) disease, have recently been found in Beijing, China. A phytoplasma from symptomatic E. bungeanus plants was identified by 16S rRNA polymerase chain reaction ( PCR) using the phytoplasma-specific universal primer pair R16mF2/R16mR1. Inoculation of healthy E. bungeanus plants by grafting with diseased scions was also performed. The rp and secY genes of the Eb WB phytoplasma were cloned and sequenced as was the 16S rRNA gene. Sequence and phylogenetic analyses of 16S rRNA, rp and secY genes indicated that the phytoplasma associated with E. bungeanus belongs to the 16SrV-B, rpV-C and secY-C subgroup, the same subgroup as the jujube witches' broom ( JWB) phytoplasma that is widely distributed among jujube trees in China. Comparative analyses based on virtual restriction fragment length polymorphism ( RFLP) showed that the Eb WB phytoplasma is more closely related to another 16SrV-B subgroup strain: RPWB ( Robinia pseudoacacia witches' broom). To the best of our knowledge, this is the first report of a witches' broom phytoplasma in E. bungeanus in China, and the findings add a new cultivated plant species to the already broad natural host range of 16SrV-B subgroup phytoplasmas. [ABSTRACT FROM AUTHOR]

Chinese chestnut trees ( Castanea mollissima BL.) planted in a suburb of Beijing, China developed symptoms including yellowing, leaf crinkling, little leaf, shortened internodes, and empty burrs. Transmission electron microscopy revealed presence of phytoplasma cells in phloem sieve elements of the symptomatic chestnut trees. Molecular cloning and sequence analysis of PCR-amplified near-full length 16S rRNA gene indicated that the phytoplasma associated with the Chinese chestnut yellow crinkle disease is closely related to Japanese chestnut witches'-broom phytoplasma. This is the first report of a phytoplasmal disease in Chinese chestnut trees. [ABSTRACT FROM AUTHOR]

This study determined the tuf gene sequence of the phytoplasma specific to paulownia witches’-broom from Nanyang, China (hereby designated PaWB-Ny). The PaWB-Ny tuf gene was 1185 nucleotides in length and confirmed that the phytoplasma belongs to subgroup 16SrI-D of aster yellows. Three characteristic GTP-binding protein motifs were identified based on the peptide deduced from the tuf gene sequence. Results suggested that the elongation factor EF-Tu was localized in the cytoplasm and lacked hydrophobic transmembrane domains. Antibodies against PaWB-Ny EF-Tu were prepared by rabbit immunization with glutathione-S-transferase (GST)-tagged EF-Tu fusion protein expressed in Escherichia coli. EF-Tu exhibited a molecular weight of ∼43 kDa and was detected in PaWB-infected paulownia plants by western blot analysis. Indirect enzyme-linked immunosorbent assays (ELISA) and dot blotting analyses were performed with freezing and thawing treatments during antigen preparation. Dilution of extracts to an appropriate scale significantly reduced non-specific reactions. The resultant PaWB EF-Tu antibody reacted with antigens from plants infected with periwinkle virescence and chinaberry tree witches’-broom phytoplasmas, but not those infected with jujube witches’-broom or bishopwood witches’-broom phytoplasma. The EF-Tu was characteristically localized within the phytoplasmal cytoplasm of infected plant phloem tissues. [ABSTRACT FROM AUTHOR]

Wisteria mosaic is a common disease of Wisteria spp. in many regions of China. According to a recent survey, the incidence of this disease was about 40% on ornamental wisteria in gardens and courtyards in the Beijing area, China. In the most severely affected areas, about 80% disease incidence was recorded. In 2002, mosaic symptoms on W. sinensis were found on the west campus of China Agricultural University in Beijing. The symptoms included flecking, yellowing, vein clearing, mottling or mosaic on the leaves; similar to those of wisteria mosaic disease reported in other countries.

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.