Observation On Killing Effect Of Neopredisan135-1 Aganist Baylisascaris Schroederi Eggs In Vitro And Detection Of Beta-tubulin Gene Of Baylisascaris Schroederi

Baylisascaris schroederi is one of the most common and harmful parasites of giant panda（Ailuropoda melanoleuca）,the infection rates of wild and captive giant pandas are very high.Insecticide-repellent drugs are mainly used for the prevention and control of parasites in captive giant pandas at present.Repeated drug use for a long time may lead to drug resistance,also there are reinfections with B.schroederi in captive environment.In order to further improve the prevention and control of giant panda B.schroederi,the killing effect of the disinfection Neopredisan135-1 against B.schroederi eggs was evaluated in vitro,which could be meaningful for the prevention and control of reinfections of B.schroederi in giant panda.In addition,the amino acid loci ofβ-tubulin 198 and 200 in drug resistance-related genes of B.schroederi were detected,which provided a reference for the prevention and control of B.schroederi in giant panda.1 Observation on Killing Effectof Neopredisan135-1 against Baylisascaris schroederi Eggs in vitro（Objective）In this study,the killing effect of the disinfection Neopredisan135-1 aganist B.schroederi eggs was evaluated in vitroto.It provides a reference for the prevention and control of B.schroederi infection in the captive giant pandas.（Method）Eggs of B.schroederi were isolated from the fresh feces of giant pandas,then treated with different concentrations of Neopredisan135-1(0.25 ml·L^-1、0.5 ml·L^-1、1 ml·L^-1、2 ml·L^-1and 4 ml·L^-1)along with different time（30 min,60 min,90 min and 120 min）.Eggs in control and treatment groups were cultured with 2.5% potassium dichromate solution at 28℃ simultaneously.Then the development and mortality of eggs were observed under a microscope with recorded.（Result）The results showed that the killing rate of eggs was approximate 50% after treating with 0.25 ml·L^-1 Neopredisan135-1 for 30 min,60 min or 90 min,while the death rates of eggs were 74.71%-87.64% after treating with 0.5 ml·L^-1 Neopredisan135-1 for 30 min and 60 min.It was noteworthy that 1 ml·L^-1,2 ml·L^-1 and 4 ml·L^-1 Neopredisan135-1 could cause more than 90% killing efficiency.（Conclusion）Our finding demonstrated that 1 ml·L^-1,2 ml·L^-1 and 4 ml·L^-1 Neopredisan135-1 have strong killing on B.schroederis eggs in vitro.Take the cost,killing effect and environmental factors in consideration,2 ml·L^-1 of Neopredisan 135-1 disinfectant is recommend.2 Detection of beta-tubulin gene of Baylisascaris schroederi（Objective）To investigate the benzimidazole resistance-associated genes B.schroederis in giant panda.（Method）B.schroederis were collected from wild and captive giant pandas,the genetic diversity of isotype I beta-tubulin gene was amplified by PCR and analyzed by direct sequencing.（Result）No mutation was found at 198th and 200th amino acid positions of the beta-tubulin gene.The results of genetic diversity analysis showed that haplotype diversity and nucleotide diversity were low in the eight populations.The variation of haplotype diversity ranged from 0.04300 to 0.59048,and the variation of nucleotide diversity index ranged from 0.00031 to 0.00563.The F_ST values of inter-population pairing were high,it ranged from 0.0027 to 0.7796,indicated the degree of differentiation among populations.Gene flow between individual populations is not very high.The results of AMOVA showed that 88.55% of the genetic variation exiested within the population,and different geographical locations affected the population structure of Baylisascaris schroederis.（Conclusion）There was no mutation in the benzimidazole resistance-associated genes of B.schroederis,and beta-tubulin was not associated with drug resistance.