Efficacy Of Tribendimidine Against Three Isolates Of Trichinella Spiralis In Mice

Objective：To evaluate the efficacy of tribendimidine (TBD) against3geographicalisolates of Trichinella spiralis (T.s) in mice. Strains infected with T.s in micebefore and after medication were compared by Optical microscopy (OM) andelectron microscopy (EM), described from the morphological point of view ofits mechanism of drug action and therapeutic.Methods:Isolates of T. spiralis from Henan (hereinafter referred to as HnT.s),Yunnan (referred to as YnT.s) and Heilongjiang (referred to as HljT.s) wereused in the study.144Kunming strain mice were divided into2groups:72mice in group A (adult stage,5d after infection), and72mice in group B(encapsulated larva stage,53d after infection). Group A was further dividedequally into12sub-groups. Mice in every3sub-groups were each infectedorally with200T. spiralis larvea of the3isolates respectively, and theremained3sub-groups served as untreated control. Mice in the3sub-groupsinfected with one isolates were orally treated with TBD at a single dose of10,20, and30mg/kg, respectively. Group B was treated as group A but with acourse of TBD once daily at a dose of100,200, and300mg/（kg·d）for7d,respectively. Mice in group A were sacrificed2d post-treatment and adultworms were recovered from the small intestinal and counted. Those in groupB were sacrificed10d after completion of7d treatment. The intact diaphragmwas removed and digested for collecting larvae. Worm burden and wormreduction of each treated sub-group were calculated and statistically camparedwith the respective control. Drug treatment group and control group of adultstake three different T.s isolates and capsules larvae fixed, changes in the lightmicroscope and EM its surface, the body wall and the nucleus, etc. Results:1Adult：1.1The average worm the HnT.s three teeatment groups, respectively(16.7±5.8)(11.5±5.5) and (3.8±3.4) were significantly less than the controlgroup (28.8±14.6)(P<0.01) worm reduction rates were39.0%,57.9%and86.0%.1.2The average worm the YnT.s three teeatment groups, respectively(20.8±5.46)(9.83±3.31) and (2.50±2.95) were significantly less than thecontrol group (32.0±3.7)(P<0.01) worm reduction rates were34.9%,69.3%and92.2%.1.3HljT.s of the three teeatment group the average insect, respectively(7.3±2.2)(4.3±1.0) and (2.360±0.624), no statistical differences in averageworm number of10mg/kg group and control group (10.2±4.4) significance(P>0.05), the average worm number of the other two dose groups weresignificant less than the control group (P<0.01) worm reduction rates were27.9%,57.4%and60.7%.2Encapsulated larva stage:2.1The average worm number of the HnT.s of three treatment groups,respectively (411.5±13.5)(239.7±9.1) and (121.8±11.3) were significantlyless than the control group (974.3±11.7)(P<0.05) worm reduction rates were57.8%,75.4%and87.5%.2.2The average worm number of the YnT.s of three treatment groups,respectively (139.5±14.5)(57.5±11.8) and (7.0±11.0) were significantly lessthan the control group (760.0±88.8)(P<0.05) worm reduction rates were74.5%,92.4%and99.1%.2.3Average worm number of HljT.s of the three treatment groups,respectively (1546.5±121.0)(1458.5±93.1)and(1443.3±50.6)were significantlyless than the control group (3123.8±203.6)(P<0.05) worm reduction rateswere50.5%,53.3%and61.6%.3Changes in OM and SEM adult: The control group of three differentisolates of worms of T.s was no significant differences in the drug treatment group, SEM showed parasites skin shrinkage, shrinkage degree graduallyincreased with increasing dose, longitudinal ridge disapperred.4The encapsulated larva change of OM and TEM: The control group ofthree different isolates of T.s infection of mice gastrocnemius capsules, eachcapsule package within1-3larvae. Part of the treatment group capsulesincomplete, fuzzy structure, intracapsular larval structure obscure part of theparasite disintegration or disappearance of, and seen the empty capsulepackage and healing disappear tendency empty capsular bag, with the amountof drugsincrease in parasite disintegration or disappearance of the increase inthe number. Visible capsule package wall outer electron density matrix andarranged in bundles of the reticular fibers by transmission EM. The inner layerof low electron density matrix and the fiber of the extent of polymerization.The drug treatment group, the capsule package wall was damaged, thinning ofthe inner and the outer layer of fracture. Normal larval body wall from outsideto inside turn angle cortex, the subcutaneous layer and the longitudinal musclelayer, the angle of the basic structure of the cortex into the cortex layer,substrate layer and fiber layer, in physiological activity, played an importantrole.The subcutaneous layer by a of the cell body, cell-free boundaries, includingglycogen granules, mitochondria, endoplasmic reticulumand esterase, longitudinalmuscle layer in the subcutaneous layer, arranged by a single longitudinal musclecells. Drug treatment group, the structure of the body wall, breakage ordisappearance of matrix layer and fiber layer part, the expansion of the mousediaphragm mitochondria, crest disorders or disappear, the destruction ordisappearance of multiple sarcomeres of myofibrils by the sarcoplasmic fill,muscle of the original fiber sarcoplasmic reticulum vacuoliz-ation.Conclusion:1Three different Trichinella Isolates TBD sensitivity were differert, thetreatment should be taken when the appropriate dose of TBD.2TBD against three different Trichinella Isolates adult and capsule oflarvae in mice have a certain level of effectiveness, especially YnT.s efficacysignificantly.