Study On The Identification And Biological Characteristics Of Rodents Cysticercus

The number of cestode species is huge with more than1500. Serious damage to human and animals (eg. cattle and sheep) is caused by larval cestodiasis (infections with larvae of cestodes), of which cysticercosis and hydatid disease are severe parasitic zoonoses that lead to substantial socioeconomic losses across China and worldwide. The review focuses on current progress, applications and perspectives in methods for the identification of cestodes. The present methods for identifying an unknown cestode species are mainly based on the conventional morphology, life cycle and combined molecular taxonomy. However, traditional morphological method is at a disadvantage when it is used to characterize cestode species with similar morphological characters but significant difference in genetics. Mitochondrial genes (mtDNAs) and nuclear genes have become research hotspot in the systematic taxonomy of cestodes, which will provide important basis in discovering cryptic species and characterizing one new species and lay the foundation for diagnosis, molecular epidemiology and precautionary measures of adult and larval infections of cestodes.Gouluo state, Dari county and Jiuzhi county located Qinghai province at the junction of Qinghai province, Gansu province and Sichuan province. The region’s wild predators (see more Wolves and foxes) and the stray dogs are numerous, in addition, rodents (Qinghai plateau pika and voles) run rampant, severe damage to grasslands. Most wild predators and stray dogs feed on rodents from grasslands, while rodents prairie grass or seeds for a living. Carnivorous animal faeces adhesion on the grass, it’s for the intermediate hosts. Grassland predators as final hosts of parasite provide one good wild circulation condition. In June and October2013, surveys have been proceeded at Dari and Jiuzhi country to investigate the rodent infection situation of cysticercosis respectively. Two kinds of cysticercosis which have no report at previous study were found in the two main rodents body. The host specificity is strong, that is,there no exist cross infection in the two kinds of cysticercus in the rodents body. At the same time, the cysticercus found in the same intermediate host body appearance differences in size, such as voles cysticercus, after with70%ethanol fixation, the length is0.5-1.0cm, pika cysticercus, with70%ethanol fixation, the length is4.5-10cm. The two kinds of cysticercus head quarter have rostellum (there are two circle hooks), four suction cups, no small hook on the suction cup. Research on intermediate and definitive host, has been clear about that the taxonomic position of the two kinds of rodents. The definitive host of rats cysticercus only preliminarily determines the dog, but pika cysticercus has yet no determining the definitive host.Based on the two kinds of rodents cysticercus mitochondrial genome analysis, rats cysticercus and pika cysticercus mitochondria genomes are13566bp and13747bp bases respectively. The mitochondrial genomes contain12encoding protein genes and22transcription genes for tRNA sequences, which encode seven nicotinamide adenine dinucleotide (NAD) genes,3COX genes, one cytb gene which encoding cytochrome oxidase and one atpase subunit gene (atp6), there are two ribosomal RNA transcription areas (i.e., rrnS and rrnL), after nad5gene there is a long non-coding region, the non-coding region length sizes of two cysticercus are195bp (voles cysticercus) and445bp (pika cysticercus) respectively. With12protein encoding genes translated into the amino acid sequences the statistical results show that the degree of genetic variation, the variation of amino acids has a greater extent than nucleotide sequences, this violates the character of codon mergers, but the first codon base mutation frequency and mutation amino acid sequence differences are consistent, accord with the first codon base determines the kinds of amino acids. Phylogenetic analysis, voles cysticercus and T. crassiceps, pika cysticercus and T. pisiformis have close kinship, accord with the characteristics of the host. Genetic variation strains and classification analysis, found that two regions of the voles cysticercus almost don’t mutate, but there are many differences between pika cysticercus, and exist genotype distribution of cross in two areas. This experiment through morphology, host, epidemiology and mitochondrial genome of rodents cysticercus has carried on the comprehensive research, provides abundant data, and laid a foundation for pinpointing the cysticercus classification status in the Taenia tapeworm.