Male competition conforms to a cost-benefit model,because while aggression may increase reproductive prospects,it can also increase the risk of injury.We hypothesize that an additional cost in aggressive males would b...Male competition conforms to a cost-benefit model,because while aggression may increase reproductive prospects,it can also increase the risk of injury.We hypothesize that an additional cost in aggressive males would be an increase in parasite load associated with a high energy investment into sexual competition.Some of these infections,in turn,may downmodulate the level of host aggression via energetic trade-offs.We staged dyadic male contests in the lab to investigate the relationships of multiple parasites with the agonistic behavior of lizard hosts,Sceloporus occidentalis.We also included both color and behavioral traits from opponents in the analyses because(1)color patches of lizards may serve as intraspecific signals used by conspecifics to assess the quality of opponents,and(2)contests between male lizards fit classical models of escalated aggression,where lizards increase aggression displays in response to an opponent's behavior.The results conform to our hypothesis because male lizards displayed more pushups when they had more ticks.Moreover,some parasites may modulate the levels of aggression because lizards infected by hematic coccidians performed fewer pushups.Interestingly,lizards also displayed fewer pushups when both the chroma and size of the opponent's blue patch were greater.The results thus also supported the role of the blue patch of s.occidentalis as a sexual armament,because it contributed to the deterrence of aggression from opponent lizards.We revealed that natural parasitic infections in lizard hosts can contribute to their agonistic behavior.We encourage future studies to account for parasites in behavioral testswithlizards.展开更多
Objective:To identify the presence of acarine ectoparasites and determine whether there is any potential public health risk in Panti Forest Reserve,Johore,Malaysia.Methods:Trapping of animals and avifauna was conducte...Objective:To identify the presence of acarine ectoparasites and determine whether there is any potential public health risk in Panti Forest Reserve,Johore,Malaysia.Methods:Trapping of animals and avifauna was conducted simultaneously along 5 expedition trails using 150 wire traps,10 harp traps and 30 mist nets for 6 consecutive nights.A total of 140 animals consisting of 7 species of birds,19 species of bats,6 species of rodents and 1 species of tree-shrew as well as 8 myriapods were examined.Results:Infestation rates of ticks,mesostigmatid mites and chiggers on animals examined were 24.3%,28.6%and 27.9%,respectively.Infestation on bats was low(1.5%) and none occurred on birds.Majority of ticks extracted were at immature stages(78.9%). Genera of ticks on animals were Amblyomma,Dermacentor,Haemaphysalis and Ixodes.Ixodes granulatus was the only species of licks identified from the animals.Examination of ticks under vegetation revealed 54%adults leading to identification of 3 species of ticks.A total of 7 species of mesostigmatid mites were found.6 species were on rodent,Maxomys mrifer and another one species,Laelaps nuttalli was found only on Leopoldamys sabanus.Laelaps sanguisugus was the only mesostigmatid found infesting tree-shrews.Seven genera of chiggers were identified.From this,5 genera were on rodents,4 genera on tree-shrews and 1 genus on a bat.Conclusions:A total of 16 genera,2 sub-genus and 14 species of acarine ectoparasites were found in this area. Findings of the survey demonstrate the presence of three spesies of acarine ectoparasites which have potential health risk i.e.Ixodes granulalus,Laelaps nuttalli and Leptotrombidium deliense.展开更多
Worldwide, wild birds play a vital role in the dispersal of ticks that harbour tick-borne pathogens, including Borrelia burgdorferi, the Lyme disease bacterium. Using PCR testing, we found 124 (31%) of 405 ticks (4 sp...Worldwide, wild birds play a vital role in the dispersal of ticks that harbour tick-borne pathogens, including Borrelia burgdorferi, the Lyme disease bacterium. Using PCR testing, we found 124 (31%) of 405 ticks (4 species), which were collected from 21 species of birds in far-western Canada, to be infected with B. burgdorferi. Transstadial transmission of B. burgdorferi occurred from larva to nymph, plus nymph to adult, in the avian coastal tick, Ixodes auritulus, collected from songbirds in British Columbia (B.C). Collectively, all 3 motile life stages (larva, nymph, adult) of this tick had an infection prevalence of 31% for B. burgdorferi, which suggests vector competency. A Pacific Wren was highly infested with I. auritulus immatures, and 20 (44%) of 45 ticks (2 nymphs, 43 larvae) were infected with B. burgdorferi. This heavy infestation shows the high potential to initiate a new population of ticks and to disseminate Lyme spirochetes. Epidemiologically, B. burgdorferi-infected I. auritulus larvae collected from the Spotted Towhee, Swainson’s Thrush, Pacific Wren, and Fox Sparrow suggest that these avian hosts act as reservoirs for B. burgdorferi. In this study, the western blacklegged tick, Ixodes pacificus, and Ixodes spinipalpis played a limited role in the enzootic transmission cycle of B. burgdorferi along coastal B.C. We document the first record of I. spinipalpis on a bird in Alberta. Because songbirds widely disperse Lyme disease vector ticks, primary health providers and the general public must be vigilant that outdoors people may be bitten by B. burgdorferi-infected ticks throughout far-western Canada.展开更多
Objective: To identify different stages of Ixodes granulatus(I. granulatus) based on morphological characters prior to molecular identification which is significant for confirming and identifying the nymphal stages of...Objective: To identify different stages of Ixodes granulatus(I. granulatus) based on morphological characters prior to molecular identification which is significant for confirming and identifying the nymphal stages of I. granulatus.Methods: A total of 14 individuals of adult, engorged and nymphal ticks collected from three different localities were examined morphologically using taxonomic keys, followed by PCR using cytochrome oxidase subunit I(COI). Clustering analysis based on COI sequences was carried out by constructing neighbor-joining and maximum parsimony tree to clarify the genetic variation and diversity of local I. granulatus.Results: Based on external morphological characterizations, nine individuals(64.3%)were successfully identified as I. granulatus, while five individuals were recognized only as Ixodes sp. due to lack of morphological characters visible and development during that stage. Molecular analysis of local I. granulatus using COI gene revealed 93%–94% sequence homology from available sequence in Gen Bank and was in concordance with the morphological identification. Furthermore, a low intraspecific variation was observed among the species of I. granulatus collected from different localities(0%–3.7%).Conclusions: These findings demonstrated for the first time the establishment of COI gene for identifying I. granulatus nymphal tick which is of paramount importance to the control of potential tick-borne infections in Malaysia. Moreover, this study provides evidence that a combination of morphology and molecular data was corroborated as an accurate tool for tick identification.展开更多
We document the first record of Borrelia americana in Canada. This Borrelia was detected in an avian coast tick, Ixodes auritulus (Acari: Ixodidae), collected from a Varied Thrush, Ixoreus naevius, along coastal Briti...We document the first record of Borrelia americana in Canada. This Borrelia was detected in an avian coast tick, Ixodes auritulus (Acari: Ixodidae), collected from a Varied Thrush, Ixoreus naevius, along coastal British Columbia. Using real-time PCR and DNA sequencing of the flagellin gene, we determined that the borrelial amplicon from the I. auritulus nymph was 99% homologous with B. americana type strain SCW-41. Because patients infected with B. americana can be seronegative for Lyme disease, medical professionals should be willing to pursue molecular analyses and consider treatment for patients with Lyme disease-like symptoms.展开更多
The efficacy of afoxolaner (NexGard? and NexGard Spectra?, Boehringer-Ingelheim), administered once orally at the minimum recommended dose, was assessed in dogs experimentally infested with Ixodes hexagonus ticks. The...The efficacy of afoxolaner (NexGard? and NexGard Spectra?, Boehringer-Ingelheim), administered once orally at the minimum recommended dose, was assessed in dogs experimentally infested with Ixodes hexagonus ticks. The study was a blinded, negative controlled clinical efficacy study using a randomized block design. Twenty-four Beagle dogs, 12 females and 12 males were enrolled. Dogs were randomly allocated either to the negative control group, or to one of the two treated groups. Infestations were performed with 50 adult I. hexagonus ticks on Days-2, 7 and 28. On Day 0, dogs in groups 2 and 3 were treated with NexGard? (afoxolaner) or NexGard Spectra? (afoxolaner + milbemycin oxime), respectively. Tick counts were conducted 48 hours after treatment (Day 2) and 48 hours after each subsequent infestation (Days 9 and 30). In both treated groups, afoxolaner was 100% effective against existing infestations (p ? and NexGard Spectra? respectively. NexGard? and NexGard Spectra? chewable tablets administered once orally at the minimum recommended dose were highly effective against I. hexagonus infestations for the 4 weeks duration of the study.展开更多
The emerging Babesia venatorum upsurges as a potential health threat occurring in China and other endemic countries.Few attempts to isolate and culture the Babesia species had been conducted in vitro.We collected the ...The emerging Babesia venatorum upsurges as a potential health threat occurring in China and other endemic countries.Few attempts to isolate and culture the Babesia species had been conducted in vitro.We collected the questing Ixodes persulcatus from identified endemic areas and allowed them to feed on the severe combined immunodeficiency(SCID)mice.The positive mice were chosen to provide positive erythrocytes with asexual B.venatorum for continuous culture in mouse or human erythrocytes in vitro,with RPMI 1640 medium and appropriate serum.With B.venatorum in the SCID mice,erythrocytes were cultured in vitro for confirmation by morphological observations with transmission electron microscopes.Sequences of B.venatorum were then identified by way of conventional PCR amplification.Parasitemia counts monitored the growth of B.venatorum on thin blood smears and real-time quantitative PCR in parallel.As expected,B.venatorum positive mice were harvested by sufficient attacks of I.persulcatus ticks.The erythrocytes of the infected mice were then inoculated and successfully cultured in donated erythrocytes from humans and mice in RPMI 1640 culture medium.Active growth of B.venatorum was well demonstrated in human erythrocytes with 3.3 times parasite-load when compared with a mouse under similar conditions.With the increased subcultures,a prolonged period of detectable parasitemia with much higher peak parasitemia and shorter time to reach peak parasitemia were observed in the following subcultures.A new strategy for isolation and in vitro culture of B.venatorum has been provided with a continuous supply of sufficient pathogens to satisfy human babesiosis's testings and clinical therapies.展开更多
基金American National Science Foundation and Spanish Ministerio de Economia y Competitividad provided financial support(EEBB-I-14-08326 to RM-P and EF-1241848 to BS)RM-P enjoys a postdoctoral contract(CEECIND/04084/2017)by ICETA-Instituto de Ciencias,Tecnologias e Agroambiente da Universidade do Porto and Fundacao da Ciencia e Tecnologia.Authors declare no conflict of interest.
文摘Male competition conforms to a cost-benefit model,because while aggression may increase reproductive prospects,it can also increase the risk of injury.We hypothesize that an additional cost in aggressive males would be an increase in parasite load associated with a high energy investment into sexual competition.Some of these infections,in turn,may downmodulate the level of host aggression via energetic trade-offs.We staged dyadic male contests in the lab to investigate the relationships of multiple parasites with the agonistic behavior of lizard hosts,Sceloporus occidentalis.We also included both color and behavioral traits from opponents in the analyses because(1)color patches of lizards may serve as intraspecific signals used by conspecifics to assess the quality of opponents,and(2)contests between male lizards fit classical models of escalated aggression,where lizards increase aggression displays in response to an opponent's behavior.The results conform to our hypothesis because male lizards displayed more pushups when they had more ticks.Moreover,some parasites may modulate the levels of aggression because lizards infected by hematic coccidians performed fewer pushups.Interestingly,lizards also displayed fewer pushups when both the chroma and size of the opponent's blue patch were greater.The results thus also supported the role of the blue patch of s.occidentalis as a sexual armament,because it contributed to the deterrence of aggression from opponent lizards.We revealed that natural parasitic infections in lizard hosts can contribute to their agonistic behavior.We encourage future studies to account for parasites in behavioral testswithlizards.
文摘Objective:To identify the presence of acarine ectoparasites and determine whether there is any potential public health risk in Panti Forest Reserve,Johore,Malaysia.Methods:Trapping of animals and avifauna was conducted simultaneously along 5 expedition trails using 150 wire traps,10 harp traps and 30 mist nets for 6 consecutive nights.A total of 140 animals consisting of 7 species of birds,19 species of bats,6 species of rodents and 1 species of tree-shrew as well as 8 myriapods were examined.Results:Infestation rates of ticks,mesostigmatid mites and chiggers on animals examined were 24.3%,28.6%and 27.9%,respectively.Infestation on bats was low(1.5%) and none occurred on birds.Majority of ticks extracted were at immature stages(78.9%). Genera of ticks on animals were Amblyomma,Dermacentor,Haemaphysalis and Ixodes.Ixodes granulatus was the only species of licks identified from the animals.Examination of ticks under vegetation revealed 54%adults leading to identification of 3 species of ticks.A total of 7 species of mesostigmatid mites were found.6 species were on rodent,Maxomys mrifer and another one species,Laelaps nuttalli was found only on Leopoldamys sabanus.Laelaps sanguisugus was the only mesostigmatid found infesting tree-shrews.Seven genera of chiggers were identified.From this,5 genera were on rodents,4 genera on tree-shrews and 1 genus on a bat.Conclusions:A total of 16 genera,2 sub-genus and 14 species of acarine ectoparasites were found in this area. Findings of the survey demonstrate the presence of three spesies of acarine ectoparasites which have potential health risk i.e.Ixodes granulalus,Laelaps nuttalli and Leptotrombidium deliense.
文摘Worldwide, wild birds play a vital role in the dispersal of ticks that harbour tick-borne pathogens, including Borrelia burgdorferi, the Lyme disease bacterium. Using PCR testing, we found 124 (31%) of 405 ticks (4 species), which were collected from 21 species of birds in far-western Canada, to be infected with B. burgdorferi. Transstadial transmission of B. burgdorferi occurred from larva to nymph, plus nymph to adult, in the avian coastal tick, Ixodes auritulus, collected from songbirds in British Columbia (B.C). Collectively, all 3 motile life stages (larva, nymph, adult) of this tick had an infection prevalence of 31% for B. burgdorferi, which suggests vector competency. A Pacific Wren was highly infested with I. auritulus immatures, and 20 (44%) of 45 ticks (2 nymphs, 43 larvae) were infected with B. burgdorferi. This heavy infestation shows the high potential to initiate a new population of ticks and to disseminate Lyme spirochetes. Epidemiologically, B. burgdorferi-infected I. auritulus larvae collected from the Spotted Towhee, Swainson’s Thrush, Pacific Wren, and Fox Sparrow suggest that these avian hosts act as reservoirs for B. burgdorferi. In this study, the western blacklegged tick, Ixodes pacificus, and Ixodes spinipalpis played a limited role in the enzootic transmission cycle of B. burgdorferi along coastal B.C. We document the first record of I. spinipalpis on a bird in Alberta. Because songbirds widely disperse Lyme disease vector ticks, primary health providers and the general public must be vigilant that outdoors people may be bitten by B. burgdorferi-infected ticks throughout far-western Canada.
基金Supported by National Institute of Health grant from the Ministry of Health,Malaysia(Code:JPP-IMR 11-010)
文摘Objective: To identify different stages of Ixodes granulatus(I. granulatus) based on morphological characters prior to molecular identification which is significant for confirming and identifying the nymphal stages of I. granulatus.Methods: A total of 14 individuals of adult, engorged and nymphal ticks collected from three different localities were examined morphologically using taxonomic keys, followed by PCR using cytochrome oxidase subunit I(COI). Clustering analysis based on COI sequences was carried out by constructing neighbor-joining and maximum parsimony tree to clarify the genetic variation and diversity of local I. granulatus.Results: Based on external morphological characterizations, nine individuals(64.3%)were successfully identified as I. granulatus, while five individuals were recognized only as Ixodes sp. due to lack of morphological characters visible and development during that stage. Molecular analysis of local I. granulatus using COI gene revealed 93%–94% sequence homology from available sequence in Gen Bank and was in concordance with the morphological identification. Furthermore, a low intraspecific variation was observed among the species of I. granulatus collected from different localities(0%–3.7%).Conclusions: These findings demonstrated for the first time the establishment of COI gene for identifying I. granulatus nymphal tick which is of paramount importance to the control of potential tick-borne infections in Malaysia. Moreover, this study provides evidence that a combination of morphology and molecular data was corroborated as an accurate tool for tick identification.
文摘We document the first record of Borrelia americana in Canada. This Borrelia was detected in an avian coast tick, Ixodes auritulus (Acari: Ixodidae), collected from a Varied Thrush, Ixoreus naevius, along coastal British Columbia. Using real-time PCR and DNA sequencing of the flagellin gene, we determined that the borrelial amplicon from the I. auritulus nymph was 99% homologous with B. americana type strain SCW-41. Because patients infected with B. americana can be seronegative for Lyme disease, medical professionals should be willing to pursue molecular analyses and consider treatment for patients with Lyme disease-like symptoms.
文摘The efficacy of afoxolaner (NexGard? and NexGard Spectra?, Boehringer-Ingelheim), administered once orally at the minimum recommended dose, was assessed in dogs experimentally infested with Ixodes hexagonus ticks. The study was a blinded, negative controlled clinical efficacy study using a randomized block design. Twenty-four Beagle dogs, 12 females and 12 males were enrolled. Dogs were randomly allocated either to the negative control group, or to one of the two treated groups. Infestations were performed with 50 adult I. hexagonus ticks on Days-2, 7 and 28. On Day 0, dogs in groups 2 and 3 were treated with NexGard? (afoxolaner) or NexGard Spectra? (afoxolaner + milbemycin oxime), respectively. Tick counts were conducted 48 hours after treatment (Day 2) and 48 hours after each subsequent infestation (Days 9 and 30). In both treated groups, afoxolaner was 100% effective against existing infestations (p ? and NexGard Spectra? respectively. NexGard? and NexGard Spectra? chewable tablets administered once orally at the minimum recommended dose were highly effective against I. hexagonus infestations for the 4 weeks duration of the study.
基金supported by the State Key Research Development Program of China(2019YFC1200501)State Key Program of Infectious Diseases(2017ZX10303404)Natural Science Foundation of China(81673235 and 81621005).
文摘The emerging Babesia venatorum upsurges as a potential health threat occurring in China and other endemic countries.Few attempts to isolate and culture the Babesia species had been conducted in vitro.We collected the questing Ixodes persulcatus from identified endemic areas and allowed them to feed on the severe combined immunodeficiency(SCID)mice.The positive mice were chosen to provide positive erythrocytes with asexual B.venatorum for continuous culture in mouse or human erythrocytes in vitro,with RPMI 1640 medium and appropriate serum.With B.venatorum in the SCID mice,erythrocytes were cultured in vitro for confirmation by morphological observations with transmission electron microscopes.Sequences of B.venatorum were then identified by way of conventional PCR amplification.Parasitemia counts monitored the growth of B.venatorum on thin blood smears and real-time quantitative PCR in parallel.As expected,B.venatorum positive mice were harvested by sufficient attacks of I.persulcatus ticks.The erythrocytes of the infected mice were then inoculated and successfully cultured in donated erythrocytes from humans and mice in RPMI 1640 culture medium.Active growth of B.venatorum was well demonstrated in human erythrocytes with 3.3 times parasite-load when compared with a mouse under similar conditions.With the increased subcultures,a prolonged period of detectable parasitemia with much higher peak parasitemia and shorter time to reach peak parasitemia were observed in the following subcultures.A new strategy for isolation and in vitro culture of B.venatorum has been provided with a continuous supply of sufficient pathogens to satisfy human babesiosis's testings and clinical therapies.
