Application of scanning electron microscopy in assessing the prevalence of some Setaria species in Korean cattle

Abstract

The numbers of individual Setaria species in the peritoneal cavities of Korean cattle were estimated. The worms were tentatively identified under light microscopy, and then precisely classified by SEM on the basis of unique features at the anterior and posterior ends of the adult worms. The positive rate of Setaria species was 34.2% out of 1,074 Korean cattle surveyed; that of S. digitata was 25.1%, S. marshalli 2.9% and both species 6.2%, respectively. Out of a total of 1,254 worms collected, 66.8% were female and 19.1% were male S. digitata; 9.2% were female and 5.0% were male S. marshalli, respectively. The average length of S. marshalli was somewhat longer than that of S. digitata. S. marshalli was documented for the first time in Korea.

Ultrastructural studies on Setaria digitata by scaning electron microscopy

“…Our observations were matching with the descriptions of Whitlock (1960) for S. digitata. Similarly, lactophenol cleared tapering posterior end of female worm ending in a smooth knob with a pair of lateral appendages anterior to the knob were in confirmity with the observations of Rhee et al (1994) and Subhachalat et al (1999) where as male worm having three pairs of pre-cloacal, a pair of adcloacal, three pairs of postcloacal papillae, a single spicule and a pair of lateral appendages nearer to the tip were on line with the observations of Subhachalat et al (1999) and Nakano et al (2006).…”

“…Later the worms were prepared for SEM as per the procedure of Rhee et al (1994) with minor modifications. Cleared head and tail ends of the worms were fixed in 2.5 % gluteraldehyde in 0.1 M phosphate buffer (pH 7.2) for 24 h at 4°C and postfixed in 2 % osmium tetroxide for 4 h. Later samples were dehydrated in graded ethyl alcohol and dried to critical point drying in CPD unit.…”

“…S. digitata and S. labiato-papillosa, the most common being S. digitata (Shoho 1958) which commonly dwells in peritoneal cavities without any apparent pathogenicity but in heavy infections it causes mild fibrinous peritonitis (Jayasinghe and Wijesundera 2003). The microfilariae (L 1 ) found in the blood stream of host causes microfilariosis in bovine natural hosts (Sigraskar et al 1999) and infectious form causes cerebrospinal nematodosis in unnatural hosts i.e., sheep, goat and horses (Rhee et al 1994). Morphological studies of the worms not only help in species identification but also form the basis for taxonomy, phylogenetic establishment and phylogenetic position of the parasites (Chabaud and Bain 1994).…”

“…Morphological studies of the worms not only help in species identification but also form the basis for taxonomy, phylogenetic establishment and phylogenetic position of the parasites (Chabaud and Bain 1994). Traditionally worms are identified with the aid of light microscopy on cleared worms but specific identification of the species poses problem (Yadav and Tandon 1991) in mixed infections because these worms lack specific distinguishable characters which can be recognized by light microscopy (Rhee et al 1994). Therefore the present study has been undertaken to study the fine ultrastructural details of male and female worms of S. digitata by scanning electron microscopy (SEM).…”

Occurrence of Setaria labiatopapillosa in peritoneal cavity of a crossbred cattle

“…However, at times these worms and their larval stages may cause erratic parasitism to pleural cavity, anterior chamber of eye, urinary bladder, oviduct, liver and pericardium where they cause harmful effects (Soulsby 1982). Amongst various setarial species found in cattle, Setaria digitata, S. marshalli, S. cervi and S. labiatopapillosa are the commonly encountered species (Rhee et al 1994;Tung et al 2003;Sundar et al 2005;Nakano et al 2007;Bazargani et al 2008). The current study reports the occurrence of S. labiatopapillosa in cross-bred cattle from Ludhiana district of Punjab state.…”