Isolation and phylogenetic analysis of porcine deltacoronavirus from pigs with diarrhoea in Hebei province,China

Porcine deltacoronavirus (PDC oV) is a recently identified coronavirus in the genus Deltacoronavirus that can cause enteric disease with clinical signs including diarrhoea, vomiting, dehydration and mortality in neonatal piglets. Although evidence of the prevalence of PDC oV in China is accumulating, little published information about Chinese PDC oV isolates is available. In this study, we investigated the presence of PDC oV in 49 faecal/intestinal samples from piglets with diarrhoea on different farms in Hebei province. Five samples (10.2%) were positive for PDC oV, but no coinfection of PDC oV with other enteropathogens was observed. A PDC oV strain named HB ‐BD was successfully isolated from the intestinal contents of a diarrhoeic piglet and serially propagated in swine testicular (ST ) cells for >40 passages. The complete genome of the HB ‐BD strain was sequenced and analysed. Genomic analysis showed that the HB ‐BD strain had a closer relationship with Chinese strains than those from other countries and was grouped within the Chinese PDC oV cluster. The results of this study will be valuable for further research of PDC oV genetic evolution and development of effective diagnostic reagents, assays and potential vaccines against newly emerged PDC oV strains.     

The detection and phylogenetic analysis of porcine deltacoronavirus from Guangdong Province in Southern China

Porcine deltacoronavirus (PDC oV) is a newly discovered coronavirus that causes diarrhoea, vomiting and dehydration in sucking and nursing piglets. It was first reported in Hong Kong in 2012 and has since been discovered in the United States, Canada, South Korea, mainland China, Thailand and Laos. PDC oV has been experimentally proved to lead to diarrhoea in swine and it was detected positive in pigs in Guangdong, southern China. In our study, 252 faecal and intestinal samples from sucking piglets and sows with diarrhoea were surveyed for common enteric viruses. We found a prevalence of PDC oV (21.8%), porcine epidemic diarrhoea virus (65.5%), transmissible gastroenteritis virus (0%), rotavirus group A (25.0%) and porcine kobuvirus (68.7%). We isolated 13 PDC oV strains and discovered that PDC oV infections were often co‐infections with kobuvirus rather than the commonly linked porcine epidemic diarrhoea virus. Phylogenetic analysis of S gene and N gene revealed that 11 of 13 PDC oV strains belonged to Chinese lineage. As for the left two strains, one single strain (CHN ‐GD 16‐05) belonged to American and Korean lineages while another strain (CHN ‐GD 16‐03) was similar to a Thai strain, but only in the S gene. This suggested a possible recombination event between the Thai and the newly described Chinese strain.     

Retrospective study of porcine circovirus 3 infection in China

PCV 3 is an emerging swine virus associated with porcine dermatitis and nephropathy syndrome (PDNS ), reproductive failure, respiratory diseases and systematic inflammation. Although first identified in 2015, the earliest case has been traced back to 2009 in the United States. In China, PCV 3 infection was first detected in 2015, but little information has been available about its occurrence and prevalence there before 2015. In this study, 200 porcine clinical samples collected from 20 provinces, five autonomous regions and four municipalities between 1990 and 1999 were analysed for PCV 3 infection by PCR . Results showed that 6.5% of the porcine samples collected from eight provinces and one autonomous region were PCV 3 positive, with the earliest cases occurring in 1996. Nucleotide sequence analysis showed that PCV 3 strains obtained in this study shared 96.6%–99.7% and 97.1%–99.4% sequence identity at the ORF 2 gene and genome levels with all available reference strains from China and other countries, indicating the high genetic stability of PCV 3 over the past 20 years.     

First report and phylogenetic analysis of porcine deltacoronavirus in Mexico

Porcine deltacoronavirus has caused great economic losses in the swine industry worldwide. In this study, we carried out the first detection, sequencing and characterization of this virus in Mexico. We analysed 885 rectal samples by multiplex RT‐PCR to determine coinfections. In addition, the Spike gene was amplified, sequenced and analysed phylogenetically. We found 85 positive samples for porcine deltacoronavirus, representing 9.6% of the total samples, and we determined that the most frequent coinfection was with porcine epidemic diarrhoea virus (54.1%). Four sequences of Mexican isolates were most closely related to those of the United States. The antigenic regions and the glycosylation site of the strains obtained coincide with those previously reported. This relationship is probably related to the commercial exchange of pigs between the US and Mexico and the geographical proximity of these two countries.     

新型冠状病毒肺炎暴发流行中心疫区急腹症诊治经验

目的分析新型冠状病毒肺炎(COVID-19)疫情下在中心疫区开展急腹症诊治的临床效果,总结临床经验。方法回顾性分析2020年1月24日至2020年2月29日华中科技大学同济医学院附属同济医院急诊收治和院内会诊的急腹症病人的临床处置和预后,随访结束时间为2020年3月8日。结果2020年1月24日至2020年2月29日已处置腹痛为主要表现的急腹症病人19例,其中,合并COVID-19病人(确诊及疑似病例)5例。19例病人中,有急诊手术指征并行急诊手术处置的9例,恢复顺利者7例,死亡2例,其中确诊COVID-19病人行急诊手术处置1例,死亡1例;行保守治疗并密切观察病情变化者10例(包括4例COVID-19病人),均恢复良好;随访至今未见密切接触上述COVID-19病人的医护人员出现感染表现。结论COVID-19疫情期间在中心疫区诊治急腹症病人时无论其是否是COVID-19病人都做到仔细检查,严格把握手术指征,术中熟练操作,术后密切监护及观察,同时做好医护人员个人防护。     

Characterization and evolution of the coronavirus porcine epidemic diarrhoea virus HLJBY isolated in China

A strain of porcine epidemic diarrhoea virus (PEDV), namely HLJBY, was isolated in Heilongjiang province, China. To provide insight into the understanding of the phylogenetic and the current epidemiological status of PEDV, PEDV HLJBY was compared with CV777 and other PEDV strains deposited in the GenBank. The homology between the entire genomic nucleotide sequences of PEDV HLJBY and CV777 was 97.7%. The homology of M gene was the highest (99.0%). However, the homology of ORF3 gene was 97.7%, and protein of ORF3 was 90.1%. In addition, HLJBY showed the highest nucleotide identity (99.9%) with PEDV‐SX/China/2017 strain and lowest similarity (91.2%) to PEDV/Belgorod/dom/2008 strain. We analysed the changes in S gene and its protein of PEDV HLJBY with 65 historic PEDV strains. The highest nucleotide identity was 99.9% compared with PEDV‐SX/China/2017 strain, and the lowest nucleotide identity was 60.0% compared with PEDV/Belgorod/dom/2008 strain. The length of deduced amino acid sequences of S proteins varied from 1,372 to 1,390 amino acids (aa). Compared with most aa sequences of S proteins, HLJBY exhibited 5 aa deletions (position 55, 59–61, 144). Analysis and comparison of open reading frame 3 (ORF3) proteins between HLJBY strain and other PEDV strains were also focused in this study. We revealed that the length of deduced amino acid sequences of ORF3 proteins was 80–224 aa among tested strains and the identity of HLJBY ORF3 amino acids with other PEDV strains was 71.4%–98.9%. ORF3 protein of both HLJBY strain and PEDV‐SX/China/2017 strain consists of 91 aa, with 133 aa deletions at their C' end in relation to the other tested PEDV strains. The phylogenetic tree based on different proteins or genes resulted in different phylogenetic groups. For pathogenicity evaluation of PEDV HLJBY strain, colostrum deprivation piglets were challenged with PEDV HLJBY, and PEDV reference strain CV777 as a control, the results showed that animals challenged with either of these PEDV strains developed diarrhoea, and histopathological examination of small intestines of challenged animals showed acute viral enteritis with villous atrophy in either PEDV HLJBY‐P10 or PEDV CV777‐P8 inoculated piglets.     

Epidemiological investigation and phylogenetic analysis of caprine parainfluenza virus type 3 in sheep of China

Caprine parainfluenza virus type 3 (CPIV3) is a new member of the Respirovirus genus in the Paramyxivirudae family, mainly causing respiratory disease. Up to now, accumulating evidence has focused on CPIV3 infection in goats, with little understood about its epidemiology in sheep. To that end, we collected 1,163 sheep sera samples from nine provinces/autonomous regions in 2012 and 1,863 samples from six provinces/autonomous regions during 2016–2017, with serological prevalence of 50.3% (95% CI: 47.5, 53.3) and 64.9% (95% CI: 62.9, 67.2), respectively. Pathogenic detection by qRT‐PCR was also performed on serum samples collected in 2016–2017, and the percentage of CPIV3 positive samples was 21.5% (95% CI: 19.7, 23.5). Sequence alignment and phylogenetic analyses revealed 11 novel CPIV3 strains based on the M gene sequences. The M gene and full‐length sequences of CPIV3 strains derived from sheep shared high nucleotide similarity with goat‐origin strains, indicating conserved genome characteristics between the viruses. Furthermore, sequence evolution and epidemiological analysis show that CPIV3 is widespread throughout China. This is the first report describing CPIV3 infection in sheep in China, showing a high sero‐prevalence and contributes to the assessment of the epidemiology of CPIV3 in China.     

维持性血液透析患者发生急性冠脉综合征的危险因素分析

目的 探讨影响维持性血液透析患者发生急性冠脉综合征（ACS）的危险因素。方法 回顾性分析2015年3月至2018年4月在河北省承德市中心医院和滦平县中医院血液净化中心行维持性血液透析的175例患者的临床资料,根据是否发生ACS分成两组,其中发生ACS患者57例（ACS组）,未发生ACS的118例（非ACS组）。收集患者的性别、年龄、肾衰竭的基础疾病、透析龄、发生ACS前1个月的收缩压、舒张压、脱水量及发生ACS时的血红蛋白（Hb)、C反应蛋白(CRP)、甲状旁腺素(PTH)、血白蛋白(ALB)、血脂、血尿酸(UA)、肺动脉压(PH)等指标进行比较分析;应用多因素的logistic回归分析导致ACS的危险因素。结果 ACS组的男性居多[38例（66.67%）],而房颤病史、透析前的收缩压和舒张压、超流量、红细胞分布宽度（RDW）、血钾（K⁺）低于非ACS组,ALB高于非ACS组,差异均有统计学意义（均P<0.05）。二元logistic回归分析显示：透析前的收缩压≥160 mmHg（OR=3.240,95%CI：1.255～5.367,P<0.05）和超流量≥3 500 mL/次（OR=2.797,95%CI：1.033～4.574,P<0.05）是影响维持性血液透析患者发生ACS的相关影响因素。结论 透析前血压控制不良（收缩压≥160 mmHg）、超流量过大（超流量≥3 500 mL/次）使维持性血液透析患者发生ACS的风险增加。     

Updated phylogenetic analysis of the spike gene and identification of a novel recombinant porcine epidemic diarrhoea virus strain in Taiwan

New variants of porcine epidemic diarrhoea virus (PEDV) causing a highly contagious intestinal disease, porcine epidemic diarrhoea virus (PED), have resulted in high mortality in suckling pigs across several countries since 2013. After 2015, the prevalence of the genogroup 2b (G2b) PEDVs decreased in a cyclical pattern with endemic seasonal outbreaks occasionally seen. To better understand the genetic diversity of PEDVs recently circulating in Taiwan, full‐length spike (S) genes of 31 PEDV strains from 28 pig farms collected during 2016–2018 were sequenced. While the majority of S gene sequences (from 27/28 farms) were closely related to the previous G2b PEDV strains, increased genetic diversities leading to several nonsynonymous mutations scattering in the neutralizing epitopes of the S gene were detected in PEDVs recently circulating in Taiwan. Furthermore, novel recombinant variants, the PEDV TW/Yunlin550/2018 strains exhibiting recombinant events between a previously isolated Taiwan PEDV G2b strain and a wild‐type PEDV G1a strain, were identified and further classified into a new genogroup, G1c. These results provide updated information about the genetic diversity of currently circulating PEDVs in the field and could help to develop more suitable strategies for controlling this disease.     

Retrospective detection of Brachyspira hampsonii in archived colitis cases from western Canadian swine

Mucohaemorrhagic diarrhea associated with Brachyspira hampsonii infection has emerged as a production‐limiting disease in western Canada. This pathogen was first described in North America in 2010, and reports of its detection occurred concurrently in western Canada and the United States. Since that time, Brachyspira hampsonii has been detected in Europe, both in pigs and in waterfowl. The origin of B. hampsonii and the timing and reasons for its emergence are unknown. We conducted a retrospective study of historic, archived cases of porcine colitis to determine when B. hampsonii was first evident in western Canada. A total of 206 samples from 114 cases submitted from 57 different farms or productions systems in 1984 and 1999‐2009 were screened using real‐time PCR assays targeting B. hampsonii genomovars I and II, and Brachyspira hyodysenteriae (the traditional agent of swine dysentery). In most cases, positive real‐time PCR results were confirmed by amplification and sequencing of additional gene targets. A total of 9, 7 and 5 samples tested positive for B. hampsonii (I), B. hampsonii (II) or B. hyodysenteriae respectively. The results of this study push the date of first appearance of B. hampsonii in pigs in western Canada back to 2002 (B. hampsonii (I)) and 2006 (B. hampsonii (II)), which is up to 7 years before the new species were first identified in fresh samples.     

Detection and phylogenetic analysis of porcine bocaviruses carried by murine rodents and house shrews in China

Bocaparvovirus infections of humans and both wild and domestic animals have been widely reported around the world. In this study, we detected and genetically characterized porcine bocavirus (PBoV) carried by murine rodents (Rattus norvegicus, Rattus tanezumi, and Rattus losea) and house shrews (Suncus murinus) in China. Between May 2015 and May 2017, 496 murine rodents and 23 house shrews were captured in four Chinese provinces. Nested polymerase chain reaction was used to investigate the prevalence of PBoV in throat swab, faecal and serum samples. A total of 7.5% (39/519) throat swab samples, 60.5% (309/511) faecal samples, and 22.9% (52/227) serum samples were PBoV‐positive. The prevalence among R. norvegicus and R. tanezumi was higher than that among R. losea and house shrews. PBoV‐positive samples were found in all four provinces. Phylogenetic analysis based on partial viral capsid protein 1/2 (VP1/VP2) showed that sequences obtained in this study formed a novel group (PBoV G4). In addition, five near full‐length PBoV genomes (4,715–4,798 nt) were acquired. These genomes encoded two non‐structural proteins, NS1 (1,908 nt in four genomes and 1,923 nt in the remaining genome) and NP1 (600 nt), and the structural proteins, VP1/VP2 (1,851 nt). Phylogenetic analysis showed that PBoV G4 is distinct from rodent, human, and other bocaviruses. In conclusion, PBoV G4 prevalence was high among two common murine rodents in China, and the pathogenecity of PBoV G4 need to be further clarified.     

Detection and phylogenetic analysis of porcine circovirus type 3 in central China

Porcine circovirus type 3 (PCV3) is the pathogen responsible for a new infectious disease that was first reported in 2016 in the United States. To further investigate the epidemic profile and genetic diversity of the virus, one hundred and seventy clinical samples (110 tissue samples and 60 serum samples) were collected from 41 different pig farms in 14 cities in central China, and a SYBR Green I‐based quantitative real‐time PCR method was developed to detect PCV3. The partial cap genes of four field strains from four different farms were sequenced and analysed. The results showed the detection limit was 2.19 × 10¹ genome copies/μl. Fifty‐three of 170 samples were detected as positive for PCV3, giving a PCV3‐positive rate of 31.18%, with 48.78% (20/41) of pig farms harbouring PCV3, which varied from 20% to 42.86% between 2013 and 2017. PCV3 could be detected in samples from pigs with different clinical presentations, and the PCV3‐positive rates varied for these different clinical presentations. The partial capsid genes of four PCV3 strains (designated YZ, LY‐03, NY and SP) shared 96.3%–99.4% nucleotide identity with those available in GenBank. Phylogenetic analysis based on the capsid gene of 32 PCV3 strains showed that the four PCV3 strains in this study were clustered with the China/GD2016 and South Korea Ku‐1606 strains. The results of this study will aid our understanding of the molecular epidemiology of PCV3.     

创伤性急性呼吸窘迫综合征时环氧合酶2的表达及意义

目的观察创伤性急性呼吸窘迫综合征时肺内环氧合酶表达与中性粒细胞凋亡抑制之间的关系。方法应用家兔胸部撞击伤后急性呼吸窘迫综合征模型,检测支气管肺泡灌洗液中性粒细胞凋亡改变、肺组织环氧合酶表达及支气管肺泡灌洗液中前列腺素E2浓度。结果胸部撞击伤后支气管肺泡灌洗液中性粒细胞凋亡比例随时间延长逐渐降低(82．3±7．2比65．5±8．4, P<0．05)。伤后肺组织环氧合酶表达显著升高(5．8±2．5比95．7±12．4,P<0．01),与肺支气管肺泡灌洗液中PMN凋亡比例呈负相关(r=-0．64,P<0．05)。支气管肺泡灌洗液中前列腺素E2浓度明显高于伤前(2．6±1．7比8．9±3．1,P<0．01)。结论肺内环氧合酶2活性增加与支气管肺泡内中性粒细胞凋亡抑制呈负相关,提示环氧合酶2可能参与了伤后中性粒细胞凋亡的调控。     

手术治疗急性无骨折脱位型颈髓损伤的回顾性分析

[目的]分析前路和后路内固定治疗急性无骨折脱位型颈髓损伤的临床治疗效果。[方法]对56例急性无骨折脱位型颈髓损伤的患者进行颈椎前路减压、植骨及颈椎前路带锁钢板内固定术或后路减压侧块钢板螺钉内固定术。术后定期X线片观察损伤节段的稳定性和融合情况以及有无内置物并发症,以JOA评分判定脊髓功能恢复情况。[结果]56例获得随访,时间13～48个月。平均26个月。56例患者均损伤节段稳定,植骨愈合良好,无内置物并发症,脊髓功能JOA评分平均提高5.78分,取得满意疗效;前路术式与后路术式在改善脊髓功能方面无明显差异(P>0.05)。[结论]颈椎前路和后路术式治疗无骨折脱位型颈髓损伤,能使损伤节段获得即刻、坚强的稳定,解除颈髓压迫,为颈髓功能的恢复提供了有利条件。     

Emergence of novel recombination lineage 3 of porcine reproductive and respiratory syndrome viruses in Southern China

Lineage 3 of porcine reproductive and respiratory syndrome viruses, which belong to North America type 2, has a long epidemic history in China. The novel lineage 3 viruses constantly emerging in recent years are characterized by a high detection rate and significant pathogenicity. In this study, we investigated the prevalence of lineage 3 in southern China and selected two isolated strains for genome and virulence analyses. A cross‐sectional epidemiology investigation indicated that the prevalence of lineage 3 antigens was 35.68% (95% CI: 27.6–44.3%) among 227 samples collected from over 100 infected farms from January 2016 to July 2017 in southern China. Two novel isolates of lineage 3 were selected. After 20 passages, Marc‐145 cells were not susceptible to those viruses. Full‐length genome analysis indicated that the two strains share 95.2% homology with each other and 95.7%–96.2% with highly pathogenic porcine reproductive and respiratory syndrome viruses (HP‐PRRSVs; JXA1‐like strain, lineage 8.7). Phylogenetic and molecular evolutionary results showed that for the two isolates, HP‐PRRSV provides most of the ORF1 gene. Animal experiment revealed discrepancies in virulence between the strains. Although challenge resulted in 100% morbidity, the isolate carrying most of the HP‐PRRSV ORF1 caused severe clinical symptoms and 40% mortality, whereas the other isolate containing part of the ORF1 gene caused no mortality. Overall, these findings suggest that lineage 3 viruses might be commonly circulating in most of southern China. Frequent recombination events within HP‐PRRSVs of this lineage with changing virulence could represent potential threats to the pig industry.     

Genomic and antigenic characterization of porcine epidemic diarrhoea virus strains isolated from South Korea, 2017

Porcine epidemic diarrhoea virus (PEDV ) is a globally emerging and re‐emerging enteric coronavirus in pigs causing serious economic threats to the world swine industry. Since the re‐emergence of massive PEDV outbreaks in South Korea in 2013−2014, domestic pig farms have continued to experience PED epidemics or endemics. This study represents the molecular characterization of PEDV isolates identified in diarrhoeic animals collected across the country in 2017. Initial sequencing analysis of the full‐length S genes revealed that 70% of the 2017 isolates (7/10) belong to the G2b subgroup, while the remaining isolates were classified as G1b. The data indicated that both variant G1b and global epidemic G2b strains were responsible for current PED outbreaks in South Korea. The 2017 G1b and G2b isolates shared 98.7%–99.4% and 98.1%–99.2% amino acid sequence identity at the S gene level and 99.3% and 99.0%–99.6% nucleotide sequence homology at the genome level compared to the corresponding Korean prototype G1b and G2b strains, respectively. In an interesting manner, one G2b‐like KNU ‐1705 strain was found to possess a large 39‐nucleotide deletion in the ORF 1a region theoretically encoding nonstructural protein 3. Phylogenetic analysis based on the entire genome and spike protein sequences indicated that the 2017 isolates were most closely related to other global G1b or G2b strains but formed different branches within the same genogroup. These results indicate that PEDV s undergo continuous evolution in the field. In addition, one 2017 PEDV strain, KOR /KNU ‐1705/2017, was successfully isolated and propagated in Vero cells. The antisera raised against the Korean prototype 2014 G2b strain efficiently neutralized KNU ‐1705 virus infection, suggesting antigenic homology between the 2014 and 2017 PEDV strains. Our data advance the understanding of the molecular epidemiology and antigenicity of PEDV circulating in South Korea.     

Genetic and phylogenetic analysis of reemerged novel Seneca Valley virus strains in Guangdong province, 2017

From June to July 2017, six Seneca Valley virus (SVV ) strains were isolated from swine herds exhibiting SVV ‐associated porcine idiopathic vesicular disease (PIVD ) in Guangdong province, China. Complete genomic sequences of these six newly identified strains were genetically and phylogenetically analysed. The results revealed that these six SVV strains were genetically closely related to USA /GBI 29/2015 and notably distinct from all previous Chinese strains, indicating the reemergence of new SVV strains in Guangdong province.     

Aggressive treatment of acute kidney injury and hyperkalemia improves survival in a combat relevant trauma model in swine

IntroductionOur swine model of pulmonary contusion (PC) and hemorrhagic shock (HS) was initially complicated by renal failure, hyperkalemia, and premature death. To study the effects of novel therapies on organ failure, improved survival was necessary requiring the design of an aggressive treatment regimen.MethodsAnesthetized swine sustained either PC or PC with grade V liver injury to induce HS (PC + HS). After injury, animals were resuscitated followed by either standard care (SC) with maintenance intravenous fluids (IVF) and treatment at potassium level of 6.0 mmol/L (n = 7; 3 PC, 4 PC + HS) or aggressive care (AC) with increased initial IVF, early and frequent potassium monitoring, and treatment at potassium level of 5.0 mmol/L (n = 15, 8 PC, 7 PC + HS). Hyperkalemia was treated with calcium, insulin, and glucose in both groups.ResultsSurvival to 48 h was achieved in 13/15 (87%) in the AC group and 2/7 (29%) in the SC group (p = 0.014). Compared to SC, AC improved median survival (48 vs. 18 h, p = 0.008) and lowered potassium (5.0 vs. 7.5 mmol/L), creatinine (2.4 vs. 4.0 mg/dL), BUN (27.5 vs. 39.0 mg/dL), and lactate (0.97 vs. 3.57 mmol/L) at the last observed time-point prior to death. For PC + HS animals, survival to 48 h was achieved in 6/7 in the AC group and 0/4 in the SC group with an improved median survival in the AC group (48 vs. 18 h, p = 0.011)DiscussionAggressive and early hyperkalemia treatment prolongs survival while reducing kidney injury and potassium levels in a combat relevant injury model in swine.     

The detection of porcine circovirus 3 in Guangxi,China

Porcine circovirus type 3 (PCV 3) is a novel circovirus that was firstly detected in the USA . PCV 3 is associated with porcine dermatitis and nephropathy syndrome (PDNS ), reproductive failure and cardiac and multisystemic inflammation. Latterly, PCV 3 was detected in Guangxi, China. Forty‐one of 108 (37.96%) samples and nine of 47 (19.14%) samples were PCV 3 positive in pig farms and pig slaughter houses, respectively. Three PCV 3 strains were sequenced and designated PCV 3‐China/GX 2016‐1, PCV 3‐China/GX 2016‐2 and PCV 3‐China/GX 2016‐3. The complete genome of PCV 3‐China/GX 2016‐2 and PCV 3‐China/GX 2016‐3 is both 2,000 bp in length, while PCV 3‐China/GX 2016‐1 is of 1,999 bp and has a G deletion at position of 1,155 in its genome. The complete genome and capsid nucleotide of the three PCV 3 strains identified in this study shared 97.5%–99.4% and 96.7%–99.1% identities with that of the other PCV 3 strains available in NCBI , respectively. Phylogenetic analysis based on complete genome and capsid gene of 35 PCV 3 strains showed that the three PCV 3 sequences from Guangxi Province were divided into two clusters. The results of this study contribute to the understanding of PCV 3 molecular epidemiology.