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Porcine reproductive and respiratory syndrome virus (PRRSV) is considered an important economic pathogen for the international swine industry. At present, both PRRSV-1 and PRRSV-2 have been confirmed to be co-circulating in China. However, there is little available information about the prevalence or distribution of PRRSV-1 in Guangdong province, southern China. In this study, we performed molecular detection of PRRSV-1 in 750 samples collected from 50 farms in 15 major pig farming regions in this province. After RT-PCR testing, 64% (32/50) of farms were confirmed as PRRSV-1-positive. Surprisingly, PRRSV-1 was circulating on at least one pig farm in all 15 regions; of the 750 samples, 186 samples (24.8%) were positive for PRRSV-1. Furthermore, 15 representative PRRSV-1 ORF5 sequences (606 bp) (n = 1 per region) were obtained from those PRRSV-1-positive regions. Sequence alignment analysis indicated that they shared 81.8% ~ 100% nucleotide and 81.2% ~ 100% amino acid similarity with each other. Although all current PRRSV-1 sequences were divided into pandemic subtype 1, most of them had unique glycoprotein-5 amino acid sequences that are significantly different from other known PRRSV-1 isolates. To conclude, the present findings revealed wide geographical distribution of PRRSV-1 in Guangdong province, southern China. This study further extends the epidemiological significance of PRRSV-1 in China.

Background Porcine circovirus type 3 (PCV3), as an emerging circovirus species, was reported to be widely circulating in the United States, China, South Korea and Poland. Previous studies revealed that PCV3 was mainly concentrated in sick animals with respiratory disease, skin disease, reproductive disorders and so on. However, the circulating status of PCV3 in pigs with other clinical presentations (especilly asymptomatic or diarrhea) was not well established. Findings In this study, to conduct a comparative epidemiological survey of PCV3, 80 weaned pig serum samples with severe respiratory disease (SRD), 175 weaned pig serum samples with mild respiratory disease (MRD), 216 asymptomatic weaned pig serum samples, 35 diarrheal weaned pig samples and 35 non-diarrheal weaned pig samples were collected from eight provinces of China. Via qPCR testing, PCV3 was circulating in all sampling provinces, with total positive rates varying from 1.04% to 100%. Interestingly, the PCV3-positive rate was significantly higher in weaned pigs with SRD (63.75%, 51/80) than in those weaned pigs with MRD (13.14%, 23/175) and asymptomatic pigs (1.85%, 4/216) (P

We obtained the first full-length genome sequence of canine bocavirus 2 (CBoV2) from the faeces of a healthy dog in Guangzhou city, Guangdong province, mainland China. The genome of GZHD15 consisted of 5059 nucleotides. Sequence analysis suggested that GZHD15 was close to a previously circulated Hong Kong isolate.

Schmallenberg virus (SBV) is an emerging and rampant arbovirus in Europe, and even Africa and West Asia. Investigating whether SBV existed in new regions or countries, it was very helpful for the early warning and control of SBV. In this study, we collected 317 serum samples (n = 242 for dairy cattle, n = 13 for yellow cattle, n = 21 for buffalo, and n = 41 for goats) from Guangdong province of southern China, which is located in a subtropical region and is an important distribution area for arboviral diseases. A commercial competitive enzyme-linked immunosorbent assay (cELISA) kit and a previously established real-time PCR were used to detect SBV antibody and RNA in those serum samples. Via testing, serological evidence of SBV was confirmed, with total positive rates (57.4, 15.4, 19, and 9.8%) in dairy cattle, yellow cattle, buffalo, and goats, respectively, while no positive signal for SBV RNA was found. To summarize, this study for the first time provided preliminary serological evidence of SBV infection in China, East Asia. Further investigations on molecular evidence, origin, and pathogenesis of SBV in ruminants needed to be studied in China.

Background Following the initial isolation of porcine deltacoronavirus (PDCoV) from pigs with diarrheal disease in the United States in 2014, the virus has been detected on swine farms in some provinces of China. To date, little is known about the molecular epidemiology of PDCoV in southern China where major swine production is operated. Results To investigate the prevalence of PDCoV in this region and compare its activity to other enteric disease of swine caused by porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis coronavirus (TGEV), and porcine rotavirus group C (Rota C), 390 fecal samples were collected from swine of various ages from 15 swine farms with reported diarrhea. Fecal samples were tested by reverse transcription-PCR (RT-PCR) that targeted PDCoV, PEDV, TGEV, and Rota C, respectively. PDCoV was detected exclusively from nursing piglets with an overall prevalence of approximate 1.28 % (5/390), not in suckling and fattening piglets. Interestingly, all of PDCoV-positive samples were from 2015 rather than 2012–2014. Despite a low detection rate, PDCoV emerged in each province/region of southern China. In addition, compared to TGEV (1.54 %, 5/390) or Rota C (1.28 %, 6/390), there were highly detection rates of PEDV (22.6 %, 88/390) in those samples. Notably, all five PDCoV-positive piglets were co-infected by PEDV. Furthermore, phylogenetic analysis of spike (S) and nucleocapsid (N) gene sequences of PDCoVs revealed that currently circulating PDCoVs in southern China were more closely related to other Chinese strains of PDCoVs than to those reported in United States, South Korea and Thailand. Conclusions This study demonstrated that PDCoV was present in southern China despite the low prevalence, and supported an evolutionary theory of geographical clustering of PDCoVs. Electronic supplementary material The online version of this article (doi:10.1186/s12985-016-0591-6) contains supplementary material, which is available to authorized users.

One thousand and thirty Escherichia coli isolates from food animals, animals-derived foods, and companion animals between 2007 and 2008 in Southern China were used to investigate their antimicrobial susceptibility to 14 different antimicrobials by the standard agar dilution method. More than 70% of isolates showed resistance to tetracycline, trimethoprim-sulphamethoxazole, nalidixic acid, and ampicillin. In general, resistance was less frequent in companion animal isolates vs food animals isolates, but cephalosporin and amikacin resistance was more frequent in companion animal isolates, 42.6% to 56.2% vs 14.1% to 24.3%, and 28.5% vs 18.8%, respectively, which was most likely due to the common use of these antimicrobials as treatment in pet animals. Fluoroquinolones resistance was high in all animal isolates (>50%). Food products showed lowest resistance among isolates from these three resources. PFGE analysis indicated that a majority of multidrug-resistant E. coli isolates showed unique, unrelated PFGE profiles and were unlikely to be the spread of a specific clone. This study provides useful information about the prevalence of antimicrobial resistance in E. coli isolated from animals and food products in China and provided evidence of the linkage of the use of antimicrobials in animals and its selection of antimicrobial resistance in bacterial isolates. The data from this study further warns the prudent use of antimicrobials in food and pet animals to reduce the risks of transmission of antimicrobial resistance zoonotic pathogen to humans.

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.

Ruminal impaction is considered an important internal disease in ruminants, such as dairy cows, sheep, and goats. It has been reported that its occurrence is associated with many different causes. This study describes a novel case of ruminal impaction caused by a plant, Ficus esquiroliana Levl., in Boer goats. This case suggests that Ficus esquiroliana should be taken into consideration when providing food for ruminants.