Molecular Identification of Oesophagostomum spp. from Himalayan Grey Langur

Nodular worm, Oesophagostomum spp. are most pathogenic strongyles of ruminants, pigs, non-human primates and other mammals. Transmission of Oesophagostomum parasite between humans and non-human primates are not frequent, however, it may occurs in areas where habitats are overlapped. The present study was carried out to explore the seasonal prevalence of strongyle infection in Himalayan grey langurs (Semnopithecus ajax) of Mid Himalayan range, Kumaon region, Uttarakhand over the period of six years (April 2011 to March 2017) with special emphasize on Oesophagostomum spp. The occurrence and intensity of infection was ascertained by qualitative and quantitative methods and results were compared with PCR method. The egg per gram (EPG) was determined by McMaster method from salt floatation positive samples. DNA was extracted from microscopy positive samples (n=50) and negative faecal samples (n=100); subsequently the DNA was subjected for amplification of Internal Transcribed Spacer-2 (ITS-2) of ribosomal DNA (rDNA) of Oesophagostomum spp. The overall incidence of strongyle infection based on microscopy was 12.82% (104/811). The mean EPG was varied between 171- 528±39. The genus specific PCR amplified single, 333bp Oesophgostomum spp fragment from genomic DNA. The PCR method amplified all the microscopy positive faecal samples, additionally it also revealed 29 positive out of 100 samples which were negative by microscopy. The overall prevalence of Oesophgostomum spp by PCR was 52.66 % (79/150), which indicates the higher sensitivity of the test than microscopy. The intensity of infection was more in monsoon and autumn months (from mid-August to November) and less positive cases were observed from winter and springs. The information gathered in this study revealed that Oesophagostomum is a common strongyles infecting Himalayan Grey Langur and it has zoonotic transmission potential.