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Li Z.-L.,South China Agricultural University | Li Z.-L.,Guangdong Wens Foodstuff Group Co. | Zhu L.,South China Agricultural University | Ma J.-Y.,South China Agricultural University | And 8 more authors.
Virus Genes | Year: 2012

A total of 127 porcine samples were collected from 48 farms in six provinces in south China. The positive rate of porcine epidemic diarrhea virus (PEDV) was 43.0 % (55/127), and the co-infection rate of PEDV and transmissible gastroenteritis virus (TGEV) was 12.0 % (15/ 127). The partial S gene and complete M gene were amplified from PEDV-positive strains by RT-PCR, cloned, sequenced and compared with each other, as well as with the reference strains in GenBank. Sequence homology results of the partial S gene and complete M gene showed that all south China field PEDV strains had nucleotide (deduced amino acid) sequence identities of 86.7-98.7 % (83.2-99.3 %) and 96.1-100 % (95.0-100%), respectively, with the foreign reference strains reported in GenBank. Phylogenetic analysis of the partial S gene showed that all the south China PEDV strains and two Thailand strains (08UB01 and 08RB07) belong to the same group and differ genetically from European strains and early domestic strains. Phylogenetic analysis of the complete M gene showed that all south China PEDV strains have a close relationship with most of the strains in Korea and Thailand, but differ genetically from the vaccine strain (CV777). © Springer Science+Business Media, LLC 2012.

Li Z.-Y.,Chinese Academy of Agricultural Sciences | Li Z.-Y.,Heilongjiang Bayi Agricultural University | Lu J.,Chinese Academy of Agricultural Sciences | Lu J.,Guangdong Dahuanong Animal Health Products Co. | And 4 more authors.
BioMed Research International | Year: 2015

Toxoplasma gondii with worldwide distribution has received substantial medical and scientific attentions as it causes serious clinical and veterinary problems especially for pregnant women and immunocompromised patients. Heat shock protein 40 (HSP40) plays a variety of essential roles in the pathogenesis of this protozoan parasite. In order to detail the genetic diversity of HSP40 gene, 16 T. gondii strains from different hosts and geographical locations were used in this study. Our results showed that HSP40 sequence of the examined strains was between 6621 bp and 6644 bp in length, and their A+T content was from 48.54% to 48.80%. Furthermore, sequence analysis presented 195 nucleotide mutation positions (0.12%-1.14%) including 29 positions in CDS (0.02%-0.12%) compared with T. gondii ME49 strain (ToxoDB: TGME49-265310). Phylogenetic assay revealed that T. gondii strains representing three classical genotypes (Types I, II, and III) were completely separated into different clusters by maximum parsimony (MP) method, but Type II and ToxoDB#9 strains were grouped into the same cluster. These results suggested that HSP40 gene is not a suitable marker for T. gondii population genetic research, though three classical genotypes of T. gondii could be differentiated by restriction enzymes MscI and EarI existing in amplicon C. © 2015 Zhong-Yuan Li et al.

Zhai S.-L.,South China Agricultural University | Zhai S.-L.,Guangdong Academy of Agricultural Sciences | He D.-S.,South China Agricultural University | He D.-S.,Guangdong Dahuanong Animal Health Products Co. | And 11 more authors.
Infection, Genetics and Evolution | Year: 2014

Complete genome characterization of porcine circovirus type 2 (PCV2) for bovid origins was still unclear in China. Therefore, in this study, PCV2 full-length genome of buffalo-origin was amplified and analyzed using PCR, DNAStar and MEGA 5.1. Genome size of three distinct PCV2 strains (buffalo1, buffalo2 and buffalo3) was 1767. bp (48.56% G. +. C), 1767. bp (48.67% G. +. C) and 1768. bp (48.08% G. +. C), respectively. At the nucleotide level, their identity varied from 95% to 96% for complete genome, from 97% to 97.8% for ORF1, and from 90.6% to 94.4% for ORF2. At the amino acid level, their identity varied from 98.7% to 99% for ORF1, and from 88% to 94.9% for ORF2. Online Blast analysis showed that buffalo1, buffalo2 and buffalo3 had highest nucleotide identity (varied from 99.77% to 99.83%) with porcine-origin PCV2 strains. Moreover, in the phylogenetic tree, they were divided into three different clusters and belonged to the worldwide accepted genotypes of PCV2b, PCV2c and PCV2a, respectively. To summarize, this study first recorded complete genome information of PCV2 for non-porcine origins in China. © 2014 Elsevier B.V.

Chen L.,Guangdong Dahuanong Animal Health Products Co. | Chen L.,South China Agricultural University | Yang D.,South China Agricultural University | Pan Z.,Guangdong Dahuanong Animal Health Products Co. | And 5 more authors.
Chemical Biology and Drug Design | Year: 2015

A series of novel hybrid molecules between sulfonamides and active antimicrobial 14-o-(3-carboxy-phenylsulfide)-mutilin were synthesized, and their in vitro antibacterial activities were evaluated by the broth microdilution. Results indicated that these compounds displayed potent antimicrobial activities in vitro against various drug-susceptible and drug-resistant Gram-positive bacteria such as Staphylococci and streptococci, including methicillin-resistant Staphylococcus aureus, and mycoplasma. In particular, sulfapyridine analog (6c) exhibited more potent inhibitory activity against Gram-positive bacteria and mycoplasma, including Staphylococcus aureus (MIC = 0.016-0.063 μg/mL), methicillin-resistant Staphylococcus aureus (MIC = 0.016 μg/mL), Streptococcus pneumoniae (MIC = 0.032-0.063 μg/mL), Mycoplasma gallisepticum (MIC = 0.004 μg/mL), with respect to other synthesized compounds and reference drugs sulfonamide (MIC = 8-128 μg/mL) and valnemulin (MIC = 0.004-0.5 μg/mL). Furthermore, comparison between MIC values of pleuromutilin-sulfonamide hybrids 6a-f with pleuromutilin parent compound 3 revealed that these modifications at 14 position side chain of the pleuromutilin with benzene sulfonamide could greatly improve the antibacterial activity especially against Gram-positives. © 2014 John Wiley & Sons A/S.

Zhai S.-L.,South China Agricultural University | Zhai S.-L.,Guangdong Academy of Agricultural Sciences | Chen R.-A.,South China Agricultural University | Chen R.-A.,Guangdong Dahuanong Animal Health Products Co. | And 12 more authors.
Virus Genes | Year: 2014

For the worldwide pig industries, porcine circovirus type 2 (PCV2) is an economically important pathogen. At present, the prevalence of PCV2 is common in Chinese swine herds. However, there is little information on PCV2 prevalence in non-porcine animals in China, such as bovids. Therefore, the goal of this study is to obtain the firsthand prevalence data of PCV2 in bovids in China. Two hundred and eighty serum and muscle samples from dairy cows (n = 180), buffalo (n = 50), and yellow cattle (n = 50) were analyzed by PCR. The detection results show that PCV2 infections (16 %, 8/50) only exist in buffaloes. In addition, there are different PCV2 viral DNAs identified by differential PCR in the same buffalo sample. Nucleotide sequencing and phylogenetic analysis results based on partial ORF1 and ORF2 sequences suggest that PCV2 strains have genetic diversity in buffaloes and they are divided into three different genotypes (PCV2b, PCV2d, and PCV2e, respectively). Moreover, to our knowledge, the PCV2d and PCV2e genotypes have not been previously reported in bovids. Through this study, the firsthand data of PCV2 prevalence in bovids in China was documented. © 2014, Springer Science+Business Media New York.

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