Evaluating troponin C from Psoroptes cuniculi as a diagnostic antigen for a dot‐ELISA assay to diagnose mite infestations in rabbits

Abstract

The mite Psoroptes cuniculi is globally widespread and has a serious impact on commercial rabbit breeding. In China, diagnosis of P. cuniculi is currently based on conventional clinical methods that entail numerous disadvantages, including their failure to diagnose subclinical infections. Hence, alternative measures are required, and dot-ELISA is one of the most promising strategies. We cloned and expressed the recombinant P. cuniculi troponin C gene for use as a basis for novel dot-ELISA assay to detect P. cuniculi infections in rabbits. This amplified sequence encoded a 153 amino acid protein of 17·6 kDa and theoretical pI 4·18 without signal peptide. The recombinant troponin C of P. cuniculi is an outer membrane protein and may also be a new P. cuniculi allergen. Results of dot-ELISA test showed that this novel assay had more than 90% sensitivity but low specificity in distinguishing infections with P. cuniculi or Sarcoptic scabiei, despite very high agreement between observers (97-99%; κ values ranged from 0·95 to 0·98 for inter- and intra-observer variability test). This study showed that this novel method, at present, lacks diagnostic utility. Therefore, although simple serological assays such as dot-ELISA show great promise as diagnostic tools, we suggest that troponin C is not a suitable diagnostic antigen candidate.

Preliminary analysis of Psoroptes ovis transcriptome in different developmental stages

“…In particular, we characterized putative P. ovis allergen genes and analyzed differences in in gene expression between larval and adult/nymph stages, which lays the foundations for research into the pathogenic properties of these two mite stages. At present, only eight allergen genes have been studied in-depth in P. ovis : pso2 [48], actin [49], pso1 [50], pso10 [51], pso11 [51], vitellogenin [52], gst [53], and troponin C [31]. In this study, comparisons of P. ovis DEGs against allergen protein sequences resulted in 188 predicted allergen genes.…”

“…cuniculi were reared on rabbits at the Laboratory Animal Center of Sichuan Agricultural University, China. Scrapings in the external auditory canal were harvested using tweezers, placed in microliter plates, and incubated at 37 °C for 2 h [31]. P. ovis that emerged from the scrapings were divided into two groups: larvae (named the Pso_L group), and nymphs and adults (named the Pso_N_A group).…”

The complete mitochondrial genome of the scab mite Psoroptes cuniculi (Arthropoda: Arachnida) provides insights into Acari phylogeny

“…The adult mites were isolated from ear cerumens of the rabbit, according to the previous descriptions [20]. The presence of mites was detected by light microscopic examination, and identification of P. cuniculi was conducted by morphological criteria and site of predilection [21], then fixed in 70% alcohol and stored at −20°C until use.…”

Molecular Characterization and Serodiagnostic Potential of Two Serpin Proteins in Psoroptes Ovis

“…Compared to rPsoSP2-iELISA, the rPsoSP1-iELISA displayed better diagnostic e ciency with higher values of sensitivity, speci city and AUC (rPsoSP1 -rPsoSP2: 96.0% − 90.0%; 90.91% − 78.18%; 0.988 − 0.964, respectively). Although rPsoSP1 showed cross-reaction with sera from 3/10 S. scabiei-infestation, the cross-reaction between these two ectoparasites have been proved commonly in other studies [3,32,33].…”