Abstracts Category : Other

Screening for enteric coronaviruses in fecal samples offeral pigs of California, USA

by Shristi Ghimire

Enteric coronaviruses (CoVs) of pigs includetransmissible gastroenteritis virus (TGEV), porcine epidemicdiarrhea virus (PEDV) and porcine delta coronavirus (PDCoV). Theycause significant economic losses in pig industry worldwide. In theUS, PEDV emerged in 2013 and caused the death of over 7 millionpiglets within the first year. Feral pigs have contributed to thetransmission of different viral, bacterial and parasitic infectionsto domestic pigs, other domestic animals and even to humans.However, their role in maintenance and transmission of porcineenteric CoVs is not well understood. In this study, fecal samplesof 44 feral pigs were collected from California, USA in early-mid2016. RNA was extracted from the fecal content supernatant andsubjected to conventional reverse transcription (RT)-PCR using twodifferent panCoV primers to detect the presence or absence ofporcine enteric CoVs. Quantitative RT-PCR (RT-qPCR) using PEDV Ngene and PDCoV M gene specific primers and probes were alsoperformed for amplification of specific viral genes. DNA sequencingof PCR products from likely positive sample was also performed forfurther confirmation. None of the samples were clearly positiveusing conventional RT-PCR assays. Few samples were doubtful forPEDV or PDCoV genes and showed Ct values slightly above thedetection limit. Repeated testing and/or DNA sequencing confirmedthat those samples were negative for PEDV or PDCoV presence. Ourresults indicated that no porcine enteric CoVs were circulating inthe feral pigs in California in early-mid 2016. Similar studiesfrom other states of USA with larger sample sizes will be helpfulto ascertain whether wild pigs in USA are playing a role in themaintenance and transmission of porcine enteric CoV ornot.Advisors/Committee Members: Wang, Qiuhong (Advisor).