Development of a differential multiplex real-time PCR assay for porcine circovirus type 2 (PCV2) genotypes PCV2a, PCV2b and PCV2d.

A multiplex quantitative real-time polymerase chain reaction (mqPCR) assay was developed and validated for detection and differentiation of porcine circovirus type 2 (PCV2) genotypes, PCV2a, PCV2b and PCV2d. Single nucleotide polymorphism in primers or probes was deployed for different genotype detections, while conserved sequence in the 3' end of a primer and in the middle of a probe was used for the targeted genotype. In silico analysis of 2601 PCV2 ORF2 sequences showed that the predicted strain coverage of the assay was 93.

Development of a real-time PCR assay for detection of African swine fever virus with an endogenous internal control.

Real-time PCR assays are highly sensitive, specific and rapid techniques for the identification of ASF virus (ASFV) (Section 3.8, OIE Terrestrial Manual, 2019). Although an ASFV p72 gene-based real-time PCR assay (a.

Development of a nested PCR assay for detection of Streptococcus equi subspecies equi in clinical equine specimens and comparison with a qPCR assay.

Streptococcus equi subsp. equi is a Gram positive bacterial pathogen commonly associated with strangles in horses, a respiratory disease characterized by abscessation of submandibular and retropharyngeal lymph nodes which can lead to obstruction of the airway. Several real-time PCR (qPCR) assays have been developed for detection of S.

Single-Cell-Based Digital PCR Detection and Association of Shiga Toxin-Producing Escherichia coli Serogroups and Major Virulence Genes.

serogroups O157, O26, O45, O103, O111, O121, and O145, when carrying major virulence genes, the Shiga toxin genes and and the intimin gene , are important foodborne pathogens. They are referred to as the "top 7" Shiga toxin-producing (STEC) serogroups and were declared by the USDA as adulterants to human health. Since top 7 serogroup-positive cattle feces and ground beef can also contain nonadulterant strains, regular PCR cannot confirm whether the virulence genes are carried by adulterant or nonadulterant serogroups.

Genetic diversity and prevalence of porcine circovirus type 3 (PCV3) and type 2 (PCV2) in the Midwest of the USA during 2016-2018.

In recent years, reports indicated that PCV3 may be involved in porcine dermatitis and nephropathy syndrome (PDNS)-like disease similar to that linked to PCV2. A total of 2,125 porcine samples from 910 cases were collected during 2016-2018 and tested for presence of PCV3 and PCV2 by real-time PCR assays. Results showed high prevalence of PCV3 and PCV2: 28.

Development of a multiplex real-time RT-PCR assay for simultaneous detection and differentiation of influenza A, B, C, and D viruses.

Influenza is a common and contagious respiratory disease caused by influenza A, B, C, and D viruses (IAV, IBV, ICV, and IDV). A multiplex real-time RT-PCR assay was developed for simultaneous detection of IAV, IBV, ICV, and IDV. The assay was designed to target unique sequences in the matrix gene of IBV and ICV, the RNA polymerase subunit PB1 of IDV, and combined with USDA and CDC IAV assays, both target the matrix gene.

A multiplex real-time PCR assay for the detection and differentiation of five bovine pinkeye pathogens.

Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is one of the most common eye diseases in cattle. Several pathogens have been associated with IBK cases, however, Moraxella bovis, Moraxella bovoculi, Mycoplasma bovis, Mycoplasma bovoculi and bovine herpesvirus type 1 (BHV-1) are most frequently observed. A multiplex real-time PCR assay using two reactions was developed for the detection and differentiation of these five pathogens.