Abstract. Sensitive detection of Porcine circovirus-2 (PCV-2) is very important for surveillance of postweaning multisystemic wasting syndrome. Droplet digital polymerase chain reaction (ddPCR) is novel PCR method that can achieve high precision. Our study aimed to develop a sensitive assay utilizing ddPCR to detect PCV-2. Specificity of the assay was confirmed by the failure of amplification of DNA of other relevant viruses. The detection limit for ddPCR was 25 copies/μL, a 4-fold greater sensitivity than TaqMan real-time PCR. Both methods showed a high degree of linearity (R 2 = ~1), although TaqMan real-time PCR showed less sensitivity than ddPCR for clinical detection. Our findings indicate that ddPCR might represent a promising platform for detecting PCV-2 viral loads.

A novel bacterial strain, designated as CF21(T), was isolated from the air of Ailuropoda melanoleuca enclosures in China. Cells were gram-negative, aerobic, non-motile, and rod shaped. Strain CF21(T) grew at 10-40 °C (optimum 28-30 °C) and pH 6.0-9.0 (optimum pH 7.0-8.0) and in the presence of NaCl concentrations ranging from 0.0% (w/v) to 2.0 % (optimum 0.0-1.0%). 16SrRNA gene sequence analysis indicated that strain CF21(T) belonged to genus Lysobacter within class Gammaproteobacteria and was most closely related to Luteimonas dalianensi OB44-3(T) (95.8% similarity), Lysobacter ruishenii CTN-1(T) (95.1%), Lysobacter spongiicola KMM329(T) (94.8 %), and Lysobacter daejeonensis GH1-9T (94.6%). The genomic G+C DNA content was 68.72 mol%. Major cellular fatty acids of CF21(T) were iso-C16:0 (30.22%), iso-C15:0 (25.70%), and the sum of 10-methyl C16 : 0 and/or iso-C17 : 1ω9c (21.94%). The prominent isoprenoid quinone was ubiquinone 8 (Q-8). Primary polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unknown phospholipid. DNA sequence relatedness between strain CF21(T) and L. ruishenii CTN-1(T) was 56%, which was clearly below the 70% threshold for prokaryotic species delineation. These analyses indicated that CF21(T) is a novel member of genus Lysobacter, for which the name Lysobacter chengduensis sp. nov. is proposed. The type strain is CF21(T) (=CGMCC1.15145(T) = DSM 100306(T)).

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated 25-1 T , was isolated from the air inside giant panda enclosures at the Chengdu Research Base of Giant Panda Breeding, China. Strain 25-1 T grew optimally at pH 7.0-8.0, at 28-30 °C and in the presence of NaCl concentrations from 0.0% to 0.5 %. 16S rRNA gene sequence analysis indicated that strain 25-1 T belongs to the genus Chryseobacterium within the family Flavobacteriaceae and is related most closely to C. carnis G81 T (96.4% similarity), C. lathyri RBA2-6 T (95.8% similarity), and C. zeae JM1085 T (95.8% similarity). Its genomic DNA G+C molar composition was 36.2%. The major cellular fatty acids were iso-C 15:0 (44.0%), iso-C 17:0 3OH (19.8%) and C 16:1 ω7c/ 16:1 ω6c (12.7%). The only isoprenoid quinone was menaquinone 6 (MK-6). The major polar lipids were phosphatidylethanolamine, two unidentified amino lipids and two unidentified lipids. The DNA-DNA relatedness between strain 25-1 T and C. lathyri RBA2-6 T was 38%. Phenotypic, genotypic, and phylogenetic characteristics indicated that strain 25-1 T is a novel member of the genus Chryseobacterium, for which the name C. chengduensis sp. nov. is proposed. The type strain is 25-1 T (CCTCC AB2015133 T =DSM 100396 T ).