Analysis of genetic variability within Thelazia callipaeda (Nematoda: Thelazioidea) from Europe and Asia by sequencing and mutation scanning of the mitochondrial cytochrome c oxidase subunit 1 gene

Emergence of canine ocular thelaziosis caused by Thelazia callipaeda in southern Switzerland

“…(259 from dogs, 5 from cats and 27 from foxes) were morphologically identified as T. callipaeda. Furthermore, the cox1 sequences of eight specimens (from four dogs, three foxes and one cat originating from different regions in Ticino) were identical to the sequence representing haplotype 1, confirming the low genetic variability of this nematode in Europe (Otranto et al, 2005b). showing an overall prevalence of 5.3% in the investigated area.…”

“…In order to confirm the morphological identification and to analyse the haplotype sequence, eight specimens were molecularly processed via the specific amplification by PCR of a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1 -689 bp) as previously described (Otranto et al, 2005b).…”

Human Thelaziasis, Europe

“…Thus, prevention of human thelaziasis should include control of the fl y vector by use of bed nets to protect children while they are sleeping and by keeping their faces and eyes clean. Genetic identifi cation of haplotype 1 has shown that this is the only haplotype circulating in animals (i.e., dogs, cats, and foxes) in Europe (11). This fi nding confi rms the metazoonotic potential of Thelazia spp.…”

“…Adult females are characterized by the position of the vulva, located anterior to the esophagus-intestinal junction, whereas males have 5 pairs of postcloacal papillae. To confi rm morphologic identifi cation, specimens from patients 2 and 4 were analyzed as previously described (11). Genomic DNA was isolated from each nematode, and a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (cox1, 689 bp) gene was amplifi ed by PCR.…”

“…This infection is also common in dogs ( Figure 1) and cats in Italy (10). Imported carnivore cases of thelaziasis have also been reported in Germany, the Netherlands, and Switzerland (11). The number of case reports of human thelaziasis has increased in several areas of Asia (3), where it occurs predominantly in rural communities with poor living and socioeconomic standards and mainly affects the elderly and children.…”