ABSTRACT
Schistosomosis and amphistomosis are the two economically important and widely prevalent snail-borne trematode infections in grazing cattle of southern India. Acute infections are symptomatically similar and difficult to detect by routine microscopy for eggs. The present study was directed towards the development of a copro-polymerase chain reaction (copro-PCR) for detection of bovine schistosome species, using custom-designed primers targeting 18S and 28S ribosomal RNA as well as mitochondrial DNA. The study demonstrated the enhanced diagnostic specificity of mitochondrial DNA markers over ribosomal RNA genes as genus-specific probes to detect schistosomes. We developed a sensitive PCR assay using primers designed from mitochondrial DNA sequences targeting the partial rrnl (16S rRNA), tCys (transfer RNA for cysteine) and partial rrnS (12S rRNA) genes of Schistosoma spindale to specifically detect schistosome infection from faecal samples of naturally infected bovines. The salient findings of the work also throw light on to the high similarity of the ribosomal RNA gene sequences of schistosomes with those of Gastrothylax crumenifer and Fischoederius elongatus, the most prevalent pouched amphistomes of the region. Further investigation has to be directed towards unravelling the complete gene sequences of 18S and 28S ribosomal RNA as well as mitochondrial DNA sequences of amphistome isolates from India.
Subject(s)
Cattle Diseases/parasitology , Polymerase Chain Reaction/methods , Schistosoma/isolation & purification , Schistosomiasis/veterinary , Animals , Cattle , Cattle Diseases/diagnosis , DNA Primers/genetics , DNA, Helminth/genetics , India , Schistosoma/classification , Schistosoma/genetics , Schistosomiasis/parasitologyABSTRACT
The present communication deals with the detection and characterization of deltamethrin resistance in tick populations using biological (larval packet test), biochemical (esterase enzyme assay) and molecular assays. Ticks were collected from cattle farms of Korutla, Telangana (KOR), Mehboob Nagar, Telangana (MBN), Nagpur, Maharashtra (NAG), Parbani, Maharashtra (PBN), Madhavaram, Tamil Nadu (MAD), Cuddalore, Tamil Nadu (CUD), Sakhleshpur, Karnataka (SAK) and Buvenduvella, Karnataka (BUV). Out of eight field isolates, seven were identified as Rhipicephalus (Boophilus) microplus while one isolate (CUD) was identified as R. (B.) annulatus. The LC50 values and resistance factors (RF) of field isolates were assessed by larval packet test (LPT). RF values of two isolates viz., Korutla and Parbhani (KOR, PAR) were close to that of reference susceptible isolate. R. (B.) microplus isolate from Nagpur (NAG) and Sakleshpur (SAK) revealed slightly higher RF values (6.42 and 4.51). They revealed slightly elevated esterase enzyme activity too. Other isolates did not reveal higher values for RF or esterase activity. Previously identified mutations conferring synthetic pyrethroid resistance in R. (B.) microplus populations were analysed by sequencing the mutation flanking regions of the carboxyl esterase and the sodium channel genes (domain III S6 and domain II S4-5 linker region). However, these point mutations were not detected in the field isolates. The results of the present study revealed that low levels of synthetic pyrethroid resistance had developed in field populations of ticks of southern India.
