Molecular characterization of the camel nasal botfly, Cephalopina titillator (Diptera: Oestridae)

Abstract

Abstract Background Larval stages of the camel nasal botfly, Cephalopina titillator (Diptera: Oestridae), rank among the top obligate endoparasites causing nasopharyngeal myiasis. Such infestations have adverse effects on camel health, reducing their economic value. The current study’s objective is to assess the applicability of PCR using partial regions of the COI mtDNA and 28S rRNA gene sequences to identify, classify, and reveal the phylogenesis of C. titillator. Results Larvae of the 2nd and 3rd instars of C. titillator were collected from the El-Bassatin abattoir in Egypt, extracted from the nasopharyngeal passage of the Arabian camel ( Camelus dromedarius ) during postmortem inspection. Genomic DNA was successfully isolated from 10 samples of 3rd instar larvae of C. titillator and amplified using primer pairs targeting partial mitochondrial COI (916 bp) and ribosomal 28S rRNA (830 bp) gene fragments. Nucleotide sequences from five samples have been sequenced and submitted to GenBank under accession numbers OP482168 to OP482172 for the COI gene and OP482160 to OP482164 for the 28S rRNA gene fragments. The COI gene exhibited 97.3% nucleotide identity across all specimens, while the 28S rRNA gene displayed 99.74% identical nucleotides. Maximum likelihood trees were constructed based on the generalized time-reversible (GTR) model. The resulting COI phylogenetic tree demonstrated that the subfamily Oestrinae does not exhibit monophyly. Additionally, it revealed that C. titillator is a sister group to the subfamily Gasterophilinae. Despite the scarcity of data available for the 28S rRNA gene, the phylogenetic analysis utilizing 28S rRNA revealed one distinct lineage for the Egyptian camel nasal bot fly. Conclusions Molecular phylogenetic analysis was conducted using molecular markers of distinct origins (both mitochondrial and nuclear) to elucidate the evolutionary relationships within the family Oestridae. This analysis is particularly significant following the inclusion of C. titillator , a first-time discovery in Egypt.