Tian Lan

Bio: Tian Lan is an academic researcher from South China Agricultural University. The author has contributed to research in topics: Coronavirus & Biology. The author has an hindex of 6, co-authored 11 publications receiving 543 citations.

Fatal swine acute diarrhoea syndrome caused by an HKU2-related coronavirus of bat origin.

Abstract: Cross-species transmission of viruses from wildlife animal reservoirs poses a marked threat to human and animal health 1 . Bats have been recognized as one of the most important reservoirs for emerging viruses and the transmission of a coronavirus that originated in bats to humans via intermediate hosts was responsible for the high-impact emerging zoonosis, severe acute respiratory syndrome (SARS) 2–10 . Here we provide virological, epidemiological, evolutionary and experimental evidence that a novel HKU2-related bat coronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), is the aetiological agent that was responsible for a large-scale outbreak of fatal disease in pigs in China that has caused the death of 24,693 piglets across four farms. Notably, the outbreak began in Guangdong province in the vicinity of the origin of the SARS pandemic. Furthermore, we identified SADS-related CoVs with 96–98% sequence identity in 9.8% (58 out of 591) of anal swabs collected from bats in Guangdong province during 2013–2016, predominantly in horseshoe bats (Rhinolophus spp.) that are known reservoirs of SARS-related CoVs. We found that there were striking similarities between the SADS and SARS outbreaks in geographical, temporal, ecological and aetiological settings. This study highlights the importance of identifying coronavirus diversity and distribution in bats to mitigate future outbreaks that could threaten livestock, public health and economic growth. Analysis of viral samples from deceased piglets shows that a bat coronavirus was responsible for an outbreak of fatal disease in China and highlights the importance of the identification of coronavirus diversity and distribution in bats in order to mitigate future outbreaks of disease.

Detection and genome sequencing of porcine circovirus 3 in neonatal pigs with congenital tremors in South China

Abstract: Porcine circovirus 3 (PCV3) is a novel circovirus first discovered in the United States in piglets and sows with porcine dermatitis and nephropathy syndrome, reproductive failure, cardiac and multisystemic inflammation. Here, seven PCV3 strains were identified for the first time from neonatal pigs with clinical signs of congenital tremors (CT) in South China. The tissue tropism of PCV3 in CT-affected piglets was analysed by the real-time quantitative PCR, and the result showed that high loads of viral genomes were detected in the brains and hearts. The complete genomes of seven new PCV3 revealed 96.8%-99.6% nucleotide identities with eleven other PCV3 strains previously reported from the United States and China. Phylogenetic analysis based on the complete genome sequences showed that all PCV3 strains clustered together and were clearly separated from other circovirus species. This study reports on the first identification of PCV3 in CT-affected newborn piglets and provides the epidemiological information of neonatal piglets with CT in Guangdong and Guangxi Provinces of China.

The re-emerging of SADS-CoV infection in pig herds in Southern China.

Abstract: A new highly virulent swine acute diarrhoea syndrome coronavirus (SADS-CoV) emerged in Guangdong province in 2017 followed by fatal diarrhoea that involved the death of 24,693 piglets. And yet from May 2017 to January 2019, there were no new SADS cases arising in pig herds in Guangdong. In this study, we reported the recent diarrhoea outbreak of SADS-CoV in Southern China on February 2019. Intestinal samples collected from diarrhoeal piglets were detected for common swine virus and confirmed that SADS-CoV was responsible for the diarrhoea case. Meanwhile, serological investigation of sows' sera implied that SADS-CoV has existed in the farm and PEDV antibody may not directly contribute to the amplification of SADS-CoV. Homology and phylogenetic analysis of the whole genome showed that the re-emerging SADS-CoV strain shared high sequence identities with existing SADS-CoV strains and all strains clustered together in Alpha coronavirus. All in all, the report herein emphasized the re-emerging of SADS-CoV and highlights continuous monitoring for this virus.

Retrospective detection and phylogenetic analysis of swine acute diarrhoea syndrome coronavirus in pigs in southern China.

Abstract: Swine acute diarrhoea syndrome coronavirus (SADS-CoV), a novel coronavirus, was first discovered in southern China in January 2017 and caused a large scale outbreak of fatal diarrheal disease in piglets Here, we conducted a retrospective investigation of 236 samples from 45 swine farms with a clinical history of diarrheal disease to evaluate the emergence and the distribution of SADS-CoV in pigs in China Our results suggest that SADS-CoV has emerged in China at least since August 2016 Meanwhile, we detected a prevalence of SADS-CoV (4353%), porcine deltacoronavirus (883%), porcine epidemic diarrhoea virus (PEDV) (7825%), rotavirus (2177%), and transmissible gastroenteritis virus (0%), and we also found the co-infection of SADS-CoV and PEDV occurred most frequently with the rate of 1765% We screened and obtained two new complete genomes, five N and five S genes of SADS-CoV Phylogenetic analysis based on these sequences revealed that all SADS-CoV sequences in this study clustered with previously reported SADS-CoV strains to form a well defined branch that grouped with the bat coronavirus HKU2 strains This study is the first retrospective investigation for SADS-CoV and provides the epidemiological information of this new virus in China, which highlights the urgency to develop effective measures to control SADS-CoV

Origin and evolution of pathogenic coronaviruses

Abstract: Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) are two highly transmissible and pathogenic viruses that emerged in humans at the beginning of the 21st century. Both viruses likely originated in bats, and genetically diverse coronaviruses that are related to SARS-CoV and MERS-CoV were discovered in bats worldwide. In this Review, we summarize the current knowledge on the origin and evolution of these two pathogenic coronaviruses and discuss their receptor usage; we also highlight the diversity and potential of spillover of bat-borne coronaviruses, as evidenced by the recent spillover of swine acute diarrhoea syndrome coronavirus (SADS-CoV) to pigs. Coronaviruses have a broad host range and distribution, and some highly pathogenic lineages have spilled over to humans and animals. Here, Cui, Li and Shi explore the viral factors that enabled the emergence of diseases such as severe acute respiratory syndrome and Middle East respiratory syndrome.