Objective:To uncover the characteristics of tick-borne viruses in Guizhou Province.Methods:A total of 414 Rhipicephalus microplus were collected from 5 counties in Guizhou Province,China from August 2022 to October 20...Objective:To uncover the characteristics of tick-borne viruses in Guizhou Province.Methods:A total of 414 Rhipicephalus microplus were collected from 5 counties in Guizhou Province,China from August 2022 to October 2023.A group of 12 ticks from each study sites was sequenced by next generation sequencing.Results:8 contigs of Wuhan mivirus(Chuviridae,Mivirus)with the length of 2094 bp to 11580 bp and 4 contigs of Lihan tick virus(Phenuiviridae,Uukuvirus)with the length of 1401 bp to 7080 bp were obtained,respectively.The prevalence rate of Wuhan mivirus and Lihan tick virus was 51.98%and 11.30%,respectively.The identities of gene sequences of both Wuhan mivirus and Lihan tick virus were 94%-100%compared with sequences in the National Center for Biotechnology Information.The phylogenetic analysis indicated that the Wuhan mivirus detected in this study was in the same branch with the Wuhan mivirus of Sichuan isolate TIGMIC-27(NCBI Accession:OP628598)and Zhejiang isolate TIGMIC-45(NCBI Accession:OP628613).In addition,the Lihan tick virus was in the same branch with the Sichuan Lihan tick virus isolate TIGMIC-46(NCBI Accession:ON812358).Conclusions:Both Wuhan mivirus and Lihan tick virus were prevalent in Rhipicephalus microplus in Guizhou Province.More studies are needed to understand the pathogenicity and public health threats of these tick-borne viruses.展开更多
Ticks are well known as vectors of many viruses which usually do great harm to human and animal health.Yunnan Province,widely covered by flourishing vegetation and mainly relying on farming husbandry,is abundant with ...Ticks are well known as vectors of many viruses which usually do great harm to human and animal health.Yunnan Province,widely covered by flourishing vegetation and mainly relying on farming husbandry,is abundant with Rhipicephalus microplus ticks.Therefore,it is of great significance to characterize the viral profile present in R.microplus parasitizing on cattle in Yunnan Province.In this study,a total of 7387 R.microplus ticks were collected from cattle and buffalo in the northwest and southeast areas of Yunnan Province from 2015 to 2017.We investigated the virome of R.microplus using next-generation sequencing(NGS)and the prevalence of important identified viruses among tick groups by RT-PCR.It revealed the presence of diverse virus concerning chu-,rhabdo-,phlebo-,flavi-and parvo-viruses in Yunnan.These viruses consist of single-stranded,circular and segmented sense RNAs,showing a greatly diversity in genomic organization.Furthermore,continuous epidemiological survey among ticks reveals broad prevalence of three viruses(Yunnan mivirus 1,Wuhan tick vrius 1 and YN tick-associated phlebovirus 1)and two possible prevalent viruses including a flavivirus-like segmented virus(Jingmen tick virus)and a bovine hokovirus 2 in Yunnan.Serological investigation among cattle indicates that these identified viruses may be infectious to cattle and can elicit corresponding antibody.Our findings on R.microplus-associated viral community will contribute to the prevention of viral disease and tracking the viral evolution.Further analysis is needed to better elucidate the pathogenicity and natural circulation of these viruses.展开更多
Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus...Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus[R.(B.)microplus]and the adult of Haemaphrysalis bispinosa(H.bispinosa).Methods:The lyophilized C.gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH_2)(10 mM)and magnetically stirred for 6 h.Synthesized TiO_2 NPs were characterized by X-ray diffraction(XRD).Fourier transform infrared spectroscopy(FTIR),Scanning electron microscopy(SEM),and Energy dispersive X-ray spectroscopy(EDX).The synthesised TiO_2 NPs were tested against the larvae of R(B.)microplus and adult of H.bispinosa were exposed to filter paper impregnated method.Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm.The functional groups for synthesized TiO_2NPs were 1405.19,and 1053.45 cm^(-1)for-NH_2 bending,primary amines and amides and 1053.84and 1078.45 cm^(-1)for C-O.SEM micrographs of the synthesized TiO_2 NPs showed the aggregated and spherical in shape.The maximum efficacy was observed in the aqueous flower extract of C.gigantea and synthesized TiO_2 NPs against R.(B.)microplus(LC_(50)=24.63 and 5.43 mg/L and r^2=0.960 and 0.988)and against H.bispinosa(LC_(50)=35.22 and 9.15 mg/L and r^2=0.969 and 0.969).respectively.Conclusions:The synthesized TiO_2 NPs were highly stable and had significant acaricidal activity against the larvae of R.(B.)microplus and adult of H.bispinosa.This study provides the first report of synthesized TiO_2 NPs and possessed excellent anti-parasitic activity.展开更多
To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rlhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host.Methods:For saliva c...To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rlhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host.Methods:For saliva collection,engorged ticks were obtained from a controlled bovine infestation and collected by natural fall.The ticks were fixed and injected pilocarpine 0.2%for induction of salivation.Saliva was collected,lyophilized and stored at-80℃.Cytotoxic activity was assessed by the hemolysis method(25,50,100,200 and 300μg/mL)and MTT cell viability assay(2.5,5,10,20 and 40μg/mL)for 24,48 and 72 h.Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of l0,15 and 20 mg/kg;antinociceptive activity was assessed using the acetic acid-induced writhing test,and formalin-induced paw-licking in mice at dose of 15 mg/kg.Results:Saliva did not cause erythrocytes hemolysis at any concentration tested,as well as did not decrease cell viability in the MTT assay.Saliva inhibited neutrophil migration by 87%and 73%at doses of l5 and 20 mg/kg,respectively.In the nociceptive tests,saliva presented analgesic activity of69.96%in the abdominal writhing test,and of 84.41%in the formalin test.The study proves that Rlhipiceplhalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities.The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and,in future,to develop novel anti-inflammatory and analgesic drugs.展开更多
The aim of the present study was to evaluate different acaricide treatments for the control of Boophilus microplus on field-kept dairy cattle in the state of Pernambuco, Brazil. The first phase of the experiment consi...The aim of the present study was to evaluate different acaricide treatments for the control of Boophilus microplus on field-kept dairy cattle in the state of Pernambuco, Brazil. The first phase of the experiment consisted of collecting the ingurgitated female Boophilus microplus directly from the hosts for attainment of larvae. After the attainment of larvae, the artificial infestation procedure began on the cattle, with larvae ages ranging from 7 to 14 days. On Day 0, animals were separated into 12 groups to receive the corresponding treatment: Abamectin;Ivermectin;Ivermectin LA;Amitraz;Amitraz + Ivermectin;Amitraz + Ivermectin LA;Amitraz + Abamectin;Association (Cypermethrin + Chlorpyrifos + Citronella);Association + Ivermectin;Association + Ivermectin LA;Association + Abamectin;and Control. Subsequent evaluations were made on post-treatment days +7, +14, +21, +28, +35, +42, +49, +56 and +63. Analyzing the post-treatment effectiveness per day, indices revealed considerable variation ranging from 0% to 96.63%. Such indices demonstrate the significant reduction in the number of ticks on the animals in some groups, especially in the Abamectin group. The analysis of the results demonstrates that the use of different avermectines can assist in the development of Boophilus microplus control programs, thereby reducing the number of acaricide applications and production costs related to ticks.展开更多
The aim of the present study was to evaluate the ixodicide efficacy of the experimental compound 712-BF-016 against Rhipicephalus (Boophilus) microplus ticks in vitro and in cattle. The in vitro efficacy was initially...The aim of the present study was to evaluate the ixodicide efficacy of the experimental compound 712-BF-016 against Rhipicephalus (Boophilus) microplus ticks in vitro and in cattle. The in vitro efficacy was initially tested against R. Boophilus microplus larvae using the Larval Packet Test (LPT). In a 2nd study the ixodicide efficacy was tested against adult ticks using the Adult Inmersion Test (AIT). Finally, a field test with the compound was carried out using 24 steers experimentally infested with R. (Boophilus) microplus ticks which were divided into 4 groups of 6 animals each for treatment. Groups 1 and 2 received the experimental compound at concentrations of 16% and 20%, respectively, which were applied as an aspersion in a total volume of 4 liters/animal. Group 3 was equally treated but with a commercial ixodicide containing cipermethrin at a 16% concentration. Group 4 served as untreated control. The efficacy was measured on days 1, 2, 3 after treatment as the percentage of ticks present from the treated groups, relative to the ticks present in the untreated control. The results indicated a percentage mortality of 93.21% for LPT and 98.02% for AIT. The efficacy produced in cattle was 61.78%, 76.43% and 85.34% for groups 1, 2 y 3, respectively. It is concluded that there was no concordance between the results obtained in vitro with those found in cattle. Possibly the excipient used for the formulation of the experimental compound was not suitable and had some influence on the results.展开更多
In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), gluta...In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.展开更多
Objective:To determine the epidemiology of ixodid ticks in bovines of different agroclimatic zones of Punjab state,India.Methods:A total of 4 459 cattle of all age groups and sex were examined from eighteen districts ...Objective:To determine the epidemiology of ixodid ticks in bovines of different agroclimatic zones of Punjab state,India.Methods:A total of 4 459 cattle of all age groups and sex were examined from eighteen districts of five major agro-climatic zones of Punjab state,India.Results:The overall prevalence of ixodid ticks,Rhipicephalus microplus(R.microplus),Hyalomma anatolicum anatolicum(H.a.anatolicum)and mixed infestation were 58.06%,50.16%,11.34%and 3.45%,respectively.Among the various agro-climatic zones highest prevalence rate of R.microplus and H.a.anatolicum were recorded in submountain undulating region(79.36%)and western region(20.40%),respectively indicating that R.microplus prefers a hot and humid environment whereas,arid and semi arid conditions suit better for H.a.anatolicum.The overall prevalence of ixodid ticks was highest in monsoon season(83.74%),followed by summer(69.01%)and least in winters(31.64%)and a significant variation(P<0.01)was also observed;whereas,maximum prevalence of R.microplus and H.a.anatolicum were recorded in monsoon(72.42%)and summers(18.06%),respectively,Among the various age groups maximum tick infestation was recorded in calves<6 months of age(72.59%),followed by 6 months-1 year age group(61.74%)and least in>1 year age group(55.02%)and the difference was statistically significant(P<0.01),Also a significantly higher(P<0.01)infestation rates of ixodid ticks was observed in males.Conclusions:The findings of the current study would provide a basis for evolving effective control strategy for the management of ticks in bovines of the region.展开更多
Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R...Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R. (B.) microplus, and tick populations have developed resistance to these acaricides. The aim of the present study was to evaluate the effectiveness of a mixture containing P, C, or Z mixed with plant extracts through in vitro laboratory bioassays, using susceptible and triple resistant (San Alfonso) R. microplus strains. Untreated controls received only water. Results of laboratory bioassays using larval packet tests revealed an efficacy of 100% (P), 100% (Z), and 98.03% (C) using susceptible larvae, and an efficacy of 88.67% (P), 91.51% (C), and 99.27% (Z) on triple-resistant larvae. Egg laying, larvae hatching and efficacy was assessed using ticks collected from treated and untreated animals. Product Z produced a 92.04% efficacy on engorged ticks collected from experimentally-infested cattle, whereas C and P exerted 80.66% and 20.04% efficacy, respectively. Engorged females collected exclusively from control animals were challenged in vitro with the experimental products, and efficacy was as follows: 91.37% (Z), 85.95% (C), and 13.58% (P). Adding plant extracts to a pyrethroid formulation led to dramatic increases of percent reduction of both susceptible and resistant immature ticks in contrast to untreated larvae and susceptible adults. Results from this study may lead to suggesting the adoption of an acari-cide-botanical mixture strategy for tick control worldwide.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant No.82160633 and 81760605)the GZPH-NSFC-2021-17,the Guizhou Provincial Basic Research Program(Natural Science MS[2025](No.497)+1 种基金the Foundation of State Key Laboratory of Pathogen and Biosecurity of China(Grant No.SKLPBS2442)the High-level and Innovative Talents of Guizhou Province(QKH-GCC[2022]033-1).
文摘Objective:To uncover the characteristics of tick-borne viruses in Guizhou Province.Methods:A total of 414 Rhipicephalus microplus were collected from 5 counties in Guizhou Province,China from August 2022 to October 2023.A group of 12 ticks from each study sites was sequenced by next generation sequencing.Results:8 contigs of Wuhan mivirus(Chuviridae,Mivirus)with the length of 2094 bp to 11580 bp and 4 contigs of Lihan tick virus(Phenuiviridae,Uukuvirus)with the length of 1401 bp to 7080 bp were obtained,respectively.The prevalence rate of Wuhan mivirus and Lihan tick virus was 51.98%and 11.30%,respectively.The identities of gene sequences of both Wuhan mivirus and Lihan tick virus were 94%-100%compared with sequences in the National Center for Biotechnology Information.The phylogenetic analysis indicated that the Wuhan mivirus detected in this study was in the same branch with the Wuhan mivirus of Sichuan isolate TIGMIC-27(NCBI Accession:OP628598)and Zhejiang isolate TIGMIC-45(NCBI Accession:OP628613).In addition,the Lihan tick virus was in the same branch with the Sichuan Lihan tick virus isolate TIGMIC-46(NCBI Accession:ON812358).Conclusions:Both Wuhan mivirus and Lihan tick virus were prevalent in Rhipicephalus microplus in Guizhou Province.More studies are needed to understand the pathogenicity and public health threats of these tick-borne viruses.
基金This work was jointly funded by the Scientific and Technological Basis Special Project grant(2013FY113500)from the Ministry of Science and Technology of Chinathe National Natural Science Foundation of China(81874274 and 81660558)+1 种基金the National Science and Technology Major Project on Important Infectious Diseases Prevention and Control(2018ZX10734-404)the Yunnan Health Training Project of High Level Talents(L-2017027).
文摘Ticks are well known as vectors of many viruses which usually do great harm to human and animal health.Yunnan Province,widely covered by flourishing vegetation and mainly relying on farming husbandry,is abundant with Rhipicephalus microplus ticks.Therefore,it is of great significance to characterize the viral profile present in R.microplus parasitizing on cattle in Yunnan Province.In this study,a total of 7387 R.microplus ticks were collected from cattle and buffalo in the northwest and southeast areas of Yunnan Province from 2015 to 2017.We investigated the virome of R.microplus using next-generation sequencing(NGS)and the prevalence of important identified viruses among tick groups by RT-PCR.It revealed the presence of diverse virus concerning chu-,rhabdo-,phlebo-,flavi-and parvo-viruses in Yunnan.These viruses consist of single-stranded,circular and segmented sense RNAs,showing a greatly diversity in genomic organization.Furthermore,continuous epidemiological survey among ticks reveals broad prevalence of three viruses(Yunnan mivirus 1,Wuhan tick vrius 1 and YN tick-associated phlebovirus 1)and two possible prevalent viruses including a flavivirus-like segmented virus(Jingmen tick virus)and a bovine hokovirus 2 in Yunnan.Serological investigation among cattle indicates that these identified viruses may be infectious to cattle and can elicit corresponding antibody.Our findings on R.microplus-associated viral community will contribute to the prevention of viral disease and tracking the viral evolution.Further analysis is needed to better elucidate the pathogenicity and natural circulation of these viruses.
文摘Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus[R.(B.)microplus]and the adult of Haemaphrysalis bispinosa(H.bispinosa).Methods:The lyophilized C.gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH_2)(10 mM)and magnetically stirred for 6 h.Synthesized TiO_2 NPs were characterized by X-ray diffraction(XRD).Fourier transform infrared spectroscopy(FTIR),Scanning electron microscopy(SEM),and Energy dispersive X-ray spectroscopy(EDX).The synthesised TiO_2 NPs were tested against the larvae of R(B.)microplus and adult of H.bispinosa were exposed to filter paper impregnated method.Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm.The functional groups for synthesized TiO_2NPs were 1405.19,and 1053.45 cm^(-1)for-NH_2 bending,primary amines and amides and 1053.84and 1078.45 cm^(-1)for C-O.SEM micrographs of the synthesized TiO_2 NPs showed the aggregated and spherical in shape.The maximum efficacy was observed in the aqueous flower extract of C.gigantea and synthesized TiO_2 NPs against R.(B.)microplus(LC_(50)=24.63 and 5.43 mg/L and r^2=0.960 and 0.988)and against H.bispinosa(LC_(50)=35.22 and 9.15 mg/L and r^2=0.969 and 0.969).respectively.Conclusions:The synthesized TiO_2 NPs were highly stable and had significant acaricidal activity against the larvae of R.(B.)microplus and adult of H.bispinosa.This study provides the first report of synthesized TiO_2 NPs and possessed excellent anti-parasitic activity.
基金supported by FUNDECT(Foundation for Support for the Development of Education,Science and Technology of the State of Mato Grosso do Sul)(FUNDECT/CAPES N°26/2014)Coordination for the Improvement of Higher Level Education Personnel(CAPES)National Council for Scientific and Technological Development(CNPq)
文摘To evaluate the antinociceptive and anti-inflammatory activities and the toxic effects of Rlhipicephalus microplus saliva for elucidating the modulation mechanism between arthropod saliva and host.Methods:For saliva collection,engorged ticks were obtained from a controlled bovine infestation and collected by natural fall.The ticks were fixed and injected pilocarpine 0.2%for induction of salivation.Saliva was collected,lyophilized and stored at-80℃.Cytotoxic activity was assessed by the hemolysis method(25,50,100,200 and 300μg/mL)and MTT cell viability assay(2.5,5,10,20 and 40μg/mL)for 24,48 and 72 h.Anti-inflammatory activity was evaluated using the method of neutrophil migration to the peritoneal cavity of mice at doses of l0,15 and 20 mg/kg;antinociceptive activity was assessed using the acetic acid-induced writhing test,and formalin-induced paw-licking in mice at dose of 15 mg/kg.Results:Saliva did not cause erythrocytes hemolysis at any concentration tested,as well as did not decrease cell viability in the MTT assay.Saliva inhibited neutrophil migration by 87%and 73%at doses of l5 and 20 mg/kg,respectively.In the nociceptive tests,saliva presented analgesic activity of69.96%in the abdominal writhing test,and of 84.41%in the formalin test.The study proves that Rlhipiceplhalus microplus saliva has significant in vivo anti-inflammatory and antinociceptive activities.The data presented herein support the development of further studies to elucidate the active principles of Rhipicephalus microplus saliva and its mechanism of action and,in future,to develop novel anti-inflammatory and analgesic drugs.
文摘The aim of the present study was to evaluate different acaricide treatments for the control of Boophilus microplus on field-kept dairy cattle in the state of Pernambuco, Brazil. The first phase of the experiment consisted of collecting the ingurgitated female Boophilus microplus directly from the hosts for attainment of larvae. After the attainment of larvae, the artificial infestation procedure began on the cattle, with larvae ages ranging from 7 to 14 days. On Day 0, animals were separated into 12 groups to receive the corresponding treatment: Abamectin;Ivermectin;Ivermectin LA;Amitraz;Amitraz + Ivermectin;Amitraz + Ivermectin LA;Amitraz + Abamectin;Association (Cypermethrin + Chlorpyrifos + Citronella);Association + Ivermectin;Association + Ivermectin LA;Association + Abamectin;and Control. Subsequent evaluations were made on post-treatment days +7, +14, +21, +28, +35, +42, +49, +56 and +63. Analyzing the post-treatment effectiveness per day, indices revealed considerable variation ranging from 0% to 96.63%. Such indices demonstrate the significant reduction in the number of ticks on the animals in some groups, especially in the Abamectin group. The analysis of the results demonstrates that the use of different avermectines can assist in the development of Boophilus microplus control programs, thereby reducing the number of acaricide applications and production costs related to ticks.
文摘The aim of the present study was to evaluate the ixodicide efficacy of the experimental compound 712-BF-016 against Rhipicephalus (Boophilus) microplus ticks in vitro and in cattle. The in vitro efficacy was initially tested against R. Boophilus microplus larvae using the Larval Packet Test (LPT). In a 2nd study the ixodicide efficacy was tested against adult ticks using the Adult Inmersion Test (AIT). Finally, a field test with the compound was carried out using 24 steers experimentally infested with R. (Boophilus) microplus ticks which were divided into 4 groups of 6 animals each for treatment. Groups 1 and 2 received the experimental compound at concentrations of 16% and 20%, respectively, which were applied as an aspersion in a total volume of 4 liters/animal. Group 3 was equally treated but with a commercial ixodicide containing cipermethrin at a 16% concentration. Group 4 served as untreated control. The efficacy was measured on days 1, 2, 3 after treatment as the percentage of ticks present from the treated groups, relative to the ticks present in the untreated control. The results indicated a percentage mortality of 93.21% for LPT and 98.02% for AIT. The efficacy produced in cattle was 61.78%, 76.43% and 85.34% for groups 1, 2 y 3, respectively. It is concluded that there was no concordance between the results obtained in vitro with those found in cattle. Possibly the excipient used for the formulation of the experimental compound was not suitable and had some influence on the results.
文摘In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.
文摘Objective:To determine the epidemiology of ixodid ticks in bovines of different agroclimatic zones of Punjab state,India.Methods:A total of 4 459 cattle of all age groups and sex were examined from eighteen districts of five major agro-climatic zones of Punjab state,India.Results:The overall prevalence of ixodid ticks,Rhipicephalus microplus(R.microplus),Hyalomma anatolicum anatolicum(H.a.anatolicum)and mixed infestation were 58.06%,50.16%,11.34%and 3.45%,respectively.Among the various agro-climatic zones highest prevalence rate of R.microplus and H.a.anatolicum were recorded in submountain undulating region(79.36%)and western region(20.40%),respectively indicating that R.microplus prefers a hot and humid environment whereas,arid and semi arid conditions suit better for H.a.anatolicum.The overall prevalence of ixodid ticks was highest in monsoon season(83.74%),followed by summer(69.01%)and least in winters(31.64%)and a significant variation(P<0.01)was also observed;whereas,maximum prevalence of R.microplus and H.a.anatolicum were recorded in monsoon(72.42%)and summers(18.06%),respectively,Among the various age groups maximum tick infestation was recorded in calves<6 months of age(72.59%),followed by 6 months-1 year age group(61.74%)and least in>1 year age group(55.02%)and the difference was statistically significant(P<0.01),Also a significantly higher(P<0.01)infestation rates of ixodid ticks was observed in males.Conclusions:The findings of the current study would provide a basis for evolving effective control strategy for the management of ticks in bovines of the region.
文摘Acaricide resistance is a major problem that hinders the control of the cattle tick Rhipicephalus (Boophilus) microplus in Mexico. Permethrin (P), cypermethrin (C) and zeta-cypermethrin (Z) have been used to control R. (B.) microplus, and tick populations have developed resistance to these acaricides. The aim of the present study was to evaluate the effectiveness of a mixture containing P, C, or Z mixed with plant extracts through in vitro laboratory bioassays, using susceptible and triple resistant (San Alfonso) R. microplus strains. Untreated controls received only water. Results of laboratory bioassays using larval packet tests revealed an efficacy of 100% (P), 100% (Z), and 98.03% (C) using susceptible larvae, and an efficacy of 88.67% (P), 91.51% (C), and 99.27% (Z) on triple-resistant larvae. Egg laying, larvae hatching and efficacy was assessed using ticks collected from treated and untreated animals. Product Z produced a 92.04% efficacy on engorged ticks collected from experimentally-infested cattle, whereas C and P exerted 80.66% and 20.04% efficacy, respectively. Engorged females collected exclusively from control animals were challenged in vitro with the experimental products, and efficacy was as follows: 91.37% (Z), 85.95% (C), and 13.58% (P). Adding plant extracts to a pyrethroid formulation led to dramatic increases of percent reduction of both susceptible and resistant immature ticks in contrast to untreated larvae and susceptible adults. Results from this study may lead to suggesting the adoption of an acari-cide-botanical mixture strategy for tick control worldwide.
