First Report of Brown Ring Patch Caused by Waitea circinata var. circinata on Agrostis stolonifera and Poa pratensis in China.

Brown ring patch, caused by Waitea circinata var. circinata, is a recently described disease of turf grass (1,2). The disease was first reported in Japan in 2005 (2) and then in the United States (1). In late May to early September 2011, large yellow rings (20 to 30 cm in diameter) were observed on creeping bentgrass (Agrostis stolonifera) and Kentucky bluegrass (Poa pratensis) growing at the Qinghe Bay golf course, Beijing, China. Leaf blades turned from yellow to brown as the disease developed, and eventually died. The disease incidence was estimated at 20 to 30%. The rings became continuous on creeping bentgrass and Kentucky bluegrass in several putting greens. The same symptom was observed on the lawn of China Agricultural University. Symptomatic leaves were collected and incubated in high humidity at 25°C until mycelia developed. The leaves were then disinfested in 1% NaClO for 1 min, rinsed with sterile water three times, and placed on potato dextrose agar (PDA). Four isolates were obtained, including one isolate from the lawn of China Agricultural University (cau-1), and three from Qinghe Bay golf course (qhw-1, qhw-2, and qhw-3). The colonies that formed on PDA changed from white to orange over time, and minute orange to brown sclerotia (approx. 2 to 3 mm in diameter) formed after 2 weeks at 25°C. These characteristics were similar to W. circinata var. circinata (1,2). DNA was extracted from each isolate using a CTAB extraction method (3) and the internal transcribed spacer (ITS) regions were amplified with the ITS1/ITS4 universal primers. The ITS sequences of the isolated fungi (Accession Nos. JQ964235 and JQ964236) had 99 to 100% homology with the sequences of W. circinata in GenBank (Accession Nos. EU591763 and HQ207169). Pathogen inocula were prepared by inoculating autoclaved oat grains with strains qhw-1 and cau-1 respectively, followed by 4 days of incubation at 25°C. Each inoculum was placed in five spots in a uniform arrangement (5 g grain inoculum per spot) on soil in a 40 × 60 cm tray, followed by sowing bluegrass seed. In another experiment, 4-week-old bentgrass was transplanted into soil infested with 5 g grain inoculum in the middle of a 20-cm diameter pot (non-colonized grain was used as a control). There were five replicates for each isolate. Plants were then incubated in a growth chamber at 26°C and high relative humidity (>90%). After 5 to 6 days, the grass in the inoculated pots and trays began to turn yellow, and then became chlorotic and necrotic as the disease developed. Orange sclerotia were observed on the bluegrass leaves by the eighth day, and all the bentgrass turned chlorotic by the tenth day. After 2 weeks, brown ring patches formed in the trays with inoculated bluegrass. Waitea circinata var. circinata was reisolated from all inoculated plants and confirmed by morphological observation and the ITS sequences analysis as described above, while no symptoms were observed on the control plants and no isolate was obtained from them. To our knowledge, this is the first report of W. circinata var. circinata infecting turf grass in China. References: (1) K. A. De La Cerda et al. Plant Dis. 91:791, 2007. (2) T. Toda et al. Plant Dis. 89:536, 2005. (3) J. A. H. Van Burik et al. Med. Mycol. 36:299, 1998.

Changes in peripheral lymphocyte subsets in patients after partial microwave ablation of the spleen for secondary splenomegaly and hypersplenism: a preliminary study.

PURPOSE: Microwave ablation therapy for secondary splenomegaly and hypersplenism has been shown to be effective from pre-clinical animal models and clinical investigations. This study was performed to determine its effects on the status of peripheral lymphocyte subsets in patients receiving microwave ablation of the spleen. MATERIALS AND METHODS: Ten patients with secondary splenomegaly and hypersplenism received microwave ablation of the spleen during laparoscopy or percutaneously under ultrasound guidance. The percentage peripheral blood T cells, B lymphocytes and NK cells were measured using flow cytometry before and on days 1, 3 and 7 after therapy, as well as 1 and 3 months afterwards. RESULTS: Percentages of CD3(+) and CD4(+) cells increased rapidly 1 month after therapy. There was no significant change in CD8(+), CD4(+)/CD8(+) or NK cells of the pre- and post-therapy levels and B lymphocytes increased significantly after therapy. In patients with an ablation volume (AV) less than 20% (group A), T cells increased 1 month after ablation but decreased 3 months after ablation. B lymphocytes increased significantly after surgery. Levels of NK cells were lower than that before therapy on each testing. In patients with 20-40% AV (group B), levels of T cells, B lymphocytes and NK cells showed an increase. Levels of CD4(+) cells were significantly higher in group B than in group A, 3 months after therapy. CONCLUSIONS: Microwave ablation therapy for splenomegaly and hypersplenism appears to have a favourable effect on peripheral lymphocyte subsets. A relationship may exist between the ablation volume and the level of peripheral lymphocyte subsets.

Pathotypical and genotypical characterization of strains of Newcastle disease virus isolated from outbreaks in chicken and goose flocks in some regions of China during 1985-2001.

Twenty-nine strains of Newcastle disease virus (NDV) isolated from outbreaks in chicken and goose flocks in several regions of China during 1985-2001 were characterized pathotypically and genotypically. All except one of these strains were velogenic. For genotyping, phylogenetic tree analysis (nt 47-420), restriction site mapping (nt 334-1682) and residue substitution analysis (residues 4-124) of the F gene were performed using sequences of our isolates and sequences of selected NDV strains from GenBank. The results revealed that most of these newly characterized strains belonged to six novel genetic groups that were designated as VIf, VIg, VIIc, VIId, VIIe and IX. The genotype IX viruses, to which the China challenge strain F48E8 used for vaccine evaluation belonged, were found only in China and still induced sporadic infections in certain areas. Isolates belonging to group VIf and VIg were distinct from previously reported members of genotype VI, with genetic distance from 2.5 to 12.1%. Subgenotype VIIc, VIId and VIIe viruses, which were distributed in clusters in the phylogenetic tree distinct from members of subgenotypes VIIa and VIIb, were responsible for disease outbreaks in chicken and goose flocks and circulated predominantly in southern China in recent years. Finally, cross-protective testing showed that specific-pathogen free (SPF) chickens vaccinated with La Sota vaccines can be fully protected against challenge by strains from genetic groups VIb, VIg, VIId and IX, indicating that the antigenic differences between strains of various genotypes are insufficient to change the cross-protection conferred by the commonly used vaccine.