PRELIMINARY DATA ON OCCURRENCE OF Strongylus vulgaris IN HORSES, ROMANIA: LARVAL CULTURES AND REAL-TIME PCR

Abstract

Strongylus vulgaris (Nematoda: Strongylidae) is the most pathogenic helminth parasite of horses. Despite of the increasingly reports on reducing its prevalence in well managed horse farms, surveys of horse populations across the world still document the presence of this parasite. Therefore, this study aimed to investigate the occurrence of S. vulgaris in different horse establishments in Romania. For this purpose, a total of 439 horses, originated from 20 premises and nine counties of Romania, including horses (n = 228) from three stud farms, four sport / recreational units (n = 43), and working horses (n = 168), which tested positive for strongyle infection, were included in the study. Individual fresh faecal samples with the strongyle egg per gram (EPG) count > 100 were subjected for larval culturing; subsequently third stage larvae (L3), harvested using a Baermann technique, were further subjected for morphological analysis to identify S. vulgaris species. Additionally, 64 pooled samples (obtained from 5-10 individual coprocultures) of mixed strongyle-type L3 larvae, including 27, 4, and 33 samples from stud, sport, and working-horses, respectively) were molecularly screened for S. vulgaris by Real-Time PCR. On microscopic examination of individual coprocultures, S. vulgaris L3 larvae were identified only in working horses (15.5% at individual level). Additionally, the RT-PCR confirmed S. vulgaris-DNA in 8 of screened pooled-samples, of which 7 were from working horses and 1 from stud farm horses. Altogether, the results revealed the occurrence of S. vulgaris in Romanian horses and particularly emphasized the higher sensitivity of PCR-based methods for its monitoring in horse populations. Moreover, these preliminary findings are the base for on-going molecular investigations of horses for S. vulgaris at individual level to provide useful information for a sustainable control of equine strongyles in Romania.