A novel PCR-based point-of-care method enables rapid, sensitive and reliable diagnosis of Babesia gibsoni infection in dogs

Development and Evaluation of a Semi-Nested PCR Method Based on the 18S ribosomal RNA Gene for the Detection of Babesia aktasi Infections in Goats

We developed and evaluated a semi-nested PCR assay for the detection of Babesia aktasi infection in goats based on the sequence of the B. aktasi 18S ribosomal RNA gene. Following in silico screening, the specificity of the primers was assessed using reference DNA samples, including B. ovis, B. motasi, B. crassa, B. venatorum, B. divergens, B. capreoli, Theileria ovis, and T. annulata. To determine the sensitivity of the method, blood infected with 2% parasitemia of B. aktasi was diluted to 10-fold serial dilutions. The method specifically amplified a 438 bp fragment of B. aktasi DNA, but did not demonstrate cross-amplification with the other hemoparasites tested. The sensitivity assay indicated that this PCR method was able to detect infection at a dilution of 10-8 of 2% parasitemia (0.074 parasites/200 µL). Ninety-seven blood samples collected from goats were used to analyze for B. aktasi, and the infection was detected in 18.5% of the goats. Additionally, the method was also applied to 44 field DNA samples that were detected to be positive for B. aktasi by reverse line blotting (RLB), and showed 84.1% agreement. The findings revealed that newly developed semi-nested PCR can detect B. aktasi infections in goats with high sensitivity and specificity.

Sensitive and rapid detection of Babesia species in dogs by recombinase polymerase amplification with lateral flow dipstick (RPA-LFD)

Canine babesiosis is a tick-borne disease caused by Babesia spp., which infects and destroys healthy erythrocytes, leading to mortality and morbidity in dogs. The diagnosis of babesiosis is tedious and time-consuming, especially in latent and chronic infections. Here, a recombinase polymerase amplification combined with a lateral flow dipstick (RPA-LFD) assay was developed for rapid and accurate detection of Babesia spp. in canine blood specimens based on the 18S rRNA region. The RPA-LFD assay using rpaBab264 gave specificity to Babesia spp. in dogs (B. vogeli and B. gibsoni) without cross-amplification to other parasites (apicomplexans and non-apicomplexans), with detection limit of at least 22.5 copies/μl (0.1 fg/µl) at 40 °C for at least 10 min. The whole process of DNA amplification by RPA and readout by LFD did not exceed 30 min. To determine the performance of the RPA-LFD assay, a total of 30 clinical samples was examined and compared with conventional PCR (cPCR) and multiplex HRM (mHRM). Eight dogs (26.67%) were detected as positive by RPA-LFD, while seven and six were found positive by cPCR and mHRM, respectively. RPA-LFD and cPCR showed high agreement with Babesia spp. detection with kappa > 0.9. We confirmed that the dogs were infected by B. vogeli from sequences of positive PCR results. Our findings suggested that RPA-LFD using the rpaBab264 assay offered a rapid, accurate, cost-effective and simple method for Babesia spp. detection that is feasibly applicable to be rapid kit at a pet hospital or point-of-care testing.

Performance Analysis of Novel Nucleic Acid Detection Kit for Mycoplasma pneumoniae

Respiratory tract infections caused by Mycoplasma pneumoniae is a serious risk for child health. It has been difficult to prevent and control for a variety of reasons; therefore, timely diagnosis is particularly important for treatment of patients. At present, the rapid M pneumoniae test kits based on nucleic acid amplification have been commercialized and used as primary diagnostic tools for M pneumoniae infection, but current kits are time-consuming, which is difficult to meet the requirement for accurate and rapid diagnosis of M pneumoniae during epidemics. Rapid and accurate test kits are urgently required to diagnose M pneumoniae infection. In this article, we evaluated the performance of a novel nucleic acid detection kit (A) for M pneumoniae from feasibility and sensitivity, and compared it with kit B. Results showed this kit has the advantage of being rapid, sensitive, and specific, which meets the demands for the diagnosis of M pneumoniae infection in clinical settings.