Molecular Detection of Balantioides coli in Pigs Employing the Traditional PCR and a Novel Cross-Priming...

Balantioides coli is the only ciliate with significant implications for both human and animal health. Regarding animals, B. coli primarily infects pigs. However, there is a lack of data regarding B. coli in pigs in Shanxi, a province in northern China covering 156,700 km² where pig farming is a major agricultural industry. In this study, 341 pig fecal samples collected from this province were examined for the presence of B. coli using a traditional polymerase chain reaction (PCR) method targeting the β-tubulin gene. The results showed that the overall prevalence of B. coli in the sampled pigs was 75.1%, and its prevalence varied significantly across different regions. Among the polymorphic sequences identified in this study, the genotype with zoonotic potential (genotype I) was observed. In addition, we established a cross-priming amplification (CPA) strategy-assisted lateral flow immunoassay (LFIA) biosensor for the detection of B. coli. The whole process from amplification to visual readout can be completed within 63 min without any special instrument. The biosensor exhibited a sensitivity of 100 copies/µL of plasmid DNA and specifically recognized B. coli. The results of the diagnostic performance analysis revealed that the biosensor accurately distinguished between PCR-positive and -negative fecal samples. Our results contribute to expanding our understanding of the geographical distribution and genetic diversity of B. coli in pigs and have important implications for controlling B. coli infection in pigs and humans. Also, this study provides a novel molecular tool for the detection of B. coli, particularly in resource-limited settings.