Tick infestation on birds in an urban Atlantic Forest fragment in north-eastern Brazil

Birds are important hosts for various tick species, playing a significant role in their biological life cycle and dispersion. In this study, we investigated tick infestations on birds trapped in an urban remnant of Atlantic Forest in Pernambuco state, Brazil. From February 2015 to March 2017, 541 birds belonging to 52 species were trapped with mist nets and examined for ectoparasites. Birds trapped in the late successional forest were significantly more infested than birds trapped in the early successional forest. In the same way, ectoparasite infestation varied significantly according to bird weight and collection plot. Overall, 198 birds (36.6%) belonging to 27 species were parasitized by ectoparasites (i.e., ticks, lice and/or mites). Ectoparasites were effectively collected from 111 birds, of which 99 belonging to 20 species were infested by ticks (n?=?261), namely, Amblyomma longirostre (13 nymphs), Amblyomma nodosum (21 nymphs), Amblyomma varium (one nymph), and Amblyomma spp. (five nymphs and 221 larvae). Most of the ticks (>?90%) were collected from Passeriformes. This study provides the second record of A. varium in Pernambuco state and confirms that birds, especially Passeriformes, are important hosts for larvae and nymphs of Amblyomma spp. in the Atlantic Forest biome of Pernambuco.

     

Ticks (Acari: Ixodidae) associated with small terrestrial mammals in the state of Minas Gerais, southeastern Brazil

From June 2005 to November 2010, 43 small mammals encompassing 6 species of Didelphimorphia, 8 species of Rodentia, and 1 species of Lagomorpha were found parasitized by ticks in the state of Minas Gerais, southeastern Brazil. Nine tick species, in total 186 specimens, were identified as follows: Amblyomma cajennense (larvae and nymphs) on opossums and rodents; Amblyomma ovale (nymphs) on rodents; Amblyomma parvum (nymphs) on rodents; Amblyomma coelebs (nymphs) on opossums; Amblyomma dubitatum (nymph) on opossums; Ixodes amarali (females, nymphs, and larvae) on opossums and rodents; Ixodes loricatus (male, females, nymph) on opossums; Ixodes schulzei (female) on rodents; and Haemaphysalis leporispalustris (female) on rabbits. Most of the tick-host associations found in the present study have never been recorded in the literature; those include three new host records for I. amarali, four for A. cajennense, one for A. dubitatum, two for A. ovale, and one for A. coelebs. In addition, we provide the first record of A. coelebs in the state of Minas Gerais.     

Phylogenetic insights on Mediterranean and Afrotropical <Emphasis Type="Italic">Rhipicephalus</Emphasis> species (Acari: Ixodida) based on mitochondrial DNA

This study was performed to determine the tick species that infest cattle and humans throughout an altitudinal gradient in the Yungas Biogeographic Province of Argentina. The presence of tick-borne bacteria of the genera Rickettsia, Ehrlichia and Borrelia in the collected ticks was also evaluated. Samples of ticks parasitizing cattle and humans were carried out in different seasons. Questing ticks (adults and nymphs) were collected from vegetation and analyzed to detect the presence of Rickettsia, Ehrlichia and Borrelia by a battery of different PCRs. Five species of hard ticks were found parasitizing cattle: Amblyomma sculptum, Amblyomma tonelliae, Amblyomma hadanii, Haemaphysalis juxtakochi and Ixodes pararicinus. Amblyomma sculptum (immature and adults), A. tonelliae (immature and adults), A. hadanii (larvae) and one nymph of I. pararicinus were found attached to humans. Rickettsia amblyommatis was detected in one nymph of A. hadanii. DNA of a Borrelia genospecies belonging to the B. burgdorferi s.l. complex (phylogenetically related to haplotypes previously reported in Ixodes aragaoi from Uruguay and I. pararicinus from Argentina) was detected in adults of I. pararicinus. Amblyomma sculptum and I. pararicinus appear to be the tick species more frequent on cattle in the YBP from Argentina, and A. sculptum and A. tonelliae, were the main ticks found attached to humans. The medical importance of the bacteria of the genus Rickettsia and Borrelia detected in this work remains unknown.     

Introduction of potential heartwater vectors and other exotic ticks into Florida on imported reptiles

Following the discovery of establishment of the African tortoise tick Amblyomma marmoreum in Florida, the present study was undertaken to determine the extent of introduction of exotic ticks into Florida on imported reptiles. Exotic ticks were identified on 29 (91%) of 32 reptile premises in 18 counties of Florida. The ticks, found on a variety of imported tortoises, snakes, and monitor lizards, belonged to 4 Amblyomma species (A. marmoreum, Amblyomma nuttalli, Amblyomma sabanerae, and Amblyomma sparsum) and 4 Aponomma species (Aponomma exornatum, Aponomma flavomaculatum, Aponomma latum, and Aponomma varanensis). The most commonly encountered ticks were A. latum and A. marmoreum. The identifications of A. marmoreum on 8 premises in 7 counties, and of A. sparsum on 1 premises, are of great concern because both species are vectors of heartwater, a lethal disease of cattle, sheep, goats, and deer.     

Tick prevalence and species diversity on Aldabran giant tortoises (Dipsochelys dussumieri) in relation to host range and host size in a restored ecosystem, Kenya

Tick species density and diversity on Aldabran tortoises was investigated in relation to the habitat range and size of each tortoise. Identification of tick infestation patterns forms an important aspect of effective tick control. Ten Aldabran tortoises were de‐ticked and monitored over the course of 2 months. Tick species found were Amblyomma sparsum, Amblyomma nuttalli, Amblyomma hebraeum and Boophilus decoloratus, with the most prevalent species found being A. sparsum. Tick loads varied considerably from 20 to 214 ticks per tortoise, with most ticks collected from the head/neck region. Tortoises ranging outside Haller Park had higher tick loads (70–214) compared with tortoises ranging within Haller Park (20–99). Tick load was not correlated with tortoise size. Results indicate that tick loads are related to the habitat range of the tortoises and may indirectly also be related to food preference and host food availability. Implications of the findings and appropriate tick control measures are discussed.     

Experimental transmission ofCowdria ruminantium (Rickettsiales) by the American reptile tickAmblyomma dissimile Koch, 1844

A Senegalese isolate of the rickettsiaCowdria ruminantium was transmitted transstadially by nymphs of the American reptile tickAmblyomma dissimile. Only eight nymphs, fed as larvae on a Saanen goat reacting to heartwater, were required to transmit fatal heartwater to another susceptible goat.SinceA. dissimile usually feeds on snakes, iguanas and lizards in central America, the tick is not considered to play a significant role in the transmission of heartwater between ruminants. However, the tick could play a role in maintaining a rickettsial reservoir in reptile populations, since it has been shown that an African reptile can be a subclinical carrier ofC. ruminantium, infective to vector ticks.     

Bird ticks in an area of the Cerrado of Minas Gerais State, southeast Brazil

In the present study the tick prevalence, mean intensity of infestation and species were recorded on birds captured between January 2009 and December 2010 in the Ecological Station Pirapitinga-ESEC from Minas Gerais State, Brazil. A total of 967 birds, from 15 families and 40 species were captured and 165 (17.1 %) individuals were parasitized by ticks. Of these 160 (97 %) belonged to the order Passeriformes. Five tick species were identified: Amblyomma longirostre (n = 274) was the most common species followed by Amblyomma parvum (n = 43), Amblyomma nodosum (n = 39), Amblyomma ovale (n = 24) and Riphicephalus sanguineus (n = 7). None of 61 unengorged larvae molted to nymph. The mean intensity of infestation was 2.7 ± 2.4 ticks per bird (448 ticks/165 birds) ranging from 1 to 10. Only 19 (11.4 %) birds were infested with one species of tick. The remaining birds were infested by two, three or four species of ticks. Also new hosts for all five ticks were recorded. Only nymphs were recorded throughout the year with two similar peaks during autumn and winter 2009 and 2010.     

Ticks from a Morelet's crocodile in Belize.

Parasitism of crocodilians by ticks has rarely been reported, and to our knowledge only seven published accounts exist. On 3 July 1999, we collected four ticks from a subadult Morelet's crocodile (Crocodylus moreletii) captured in northern Belize. These were identified as Amblyomma dissimile (one female), and Amblyomma sp. (two nymphs, one larva). The crocodile was captured on land approximately 100 m from water, and all four ticks were attached to loose skin on the lateral surface of the tail. Crocodilians are most susceptible to terrestrial ectoparasites, including ticks, during overland movements. However, most such movements occur in response to drought, when tick questing activity is suppressed, which likely accounts for the small numbers of tick specimens recorded from crocodilians and the absence of any noticeable impact of parasitism on host fitness.     

A Collection of Ticks (Ixodidae) from Wild Birds in Uruguay

Thirty nine wild birds from seven families (Alcedinidae, Emberizidae, Furnariidae, Parulidae, Trochilidae, Turdidae and Tyrannidae) were caught from 4 to 7 of February, 2004 at Rincón da Vassoura (31°15′ S 56°03′ W) Department of Tacuarembó, Uruguay. Ninety one nymphs and forty one larvae of Ixodidae were recovered from them. The majority of ticks were conventionally identified but 16S mitochondrial rDNA sequences were obtained for larvae and nymphs of Amblyomma with uncertain specific status to be compared with sequences of species from this genus. The 16S rDNA of Haemaphysalis juxtakochi Cooley was also obtained. Most ticks, 1 nymph of Amblyomma longirostre (Koch), 5 larvae of Amblyomma aureolatum (Pallas) and 3 nymphs of Amblyomma spp., 10 nymphs and 71 larvae of H. juxtakochi, 23 nymphs and 12 larvae of Ixodes pararicinus Keirans and Clifford, were found on the 5 Turdus albicollis Vieillot and 6 Turdus rufiventris Vieillot (Turdidae) caught. One nymph of A. longirostre and 2 nymphs of I. pararicinus were collected from the only Syndactyla rufosuperciliata (Lafresnaye) (Furnariidae) captured; 1 larva of I. pararicinus was collected on one of two Basileuterus leucoblepharus (Vieillot) (Parulidae) trapped and 1 nymph of A. longirostre was found on one of nine Elaenia parvirostris Pelzeln (Tyrannidae) captured. All these findings constitute new host records with the exception of I. pararicinus on S. rufosuperciliata, and stress the importance of Turdus as hosts for I. pararicinus, H. juxtakochi and A. aureolatum. Nymphs of H. juxtakochi and Amblyomma spp. were also found on man and vegetation.     

Importation of Exotic Ticks into the United Kingdom via the International Trade in Reptiles

Due to the increased trade in exotic reptiles, many of which are infested with ticks of various genera, there is an increased risk of exotic ticks and pathogens being introduced and potentially becoming established in new geographical areas. Despite the number and variety of tick species collected from reptiles, their role in the maintenance of pathogens and transmission to humans has not been fully investigated for all species. The potential public health risks to the United Kingdom have been examined through a preliminary study involving the collection and identification of exotic tick species imported via the reptile trade. Reptiles imported into Heathrow Airport, London (July 2003–October 2004) were carefully examined for ectoparasites. Five species of tick were collected: Aponomma exornatum, Ap. latum, Amblyomma rotundatum, Am. dissimile and Am. nuttalli. This is the first report of Am. dissimile identified from an interception at Heathrow airport. The potential for establishment of exotic ticks in the UK and the public health risks are discussed.     

Parasitism of lizards by immature stages of the blacklegged tick,Ixodes scapularis (Acari,Ixodidae)

From 1982–1985 and 1993–1999, a total of 309 individual reptiles, mostly lizards and snakes, belonging to 12 species (American alligator, six lizard species, five snake species) was captured on St. Catherine's Island, Liberty County, Georgia, USA, and examined for ticks. Three lizard species, the broad-headed skink Eumeces laticeps, southeastern 5-lined skink Eumeces inexpectatus, and eastern glass lizard Ophisaurus ventralis, were severely infested with larvae and nymphs of the blacklegged tick, Ixodes scapularis. Ticks were not found on any of the other reptile species. Overall, 80% of 65 E. inexpectatus examined were parasitized by a mean intensity of 21.5larvae and 88% were parasitized by a mean intensity of 4.8 nymphs. Corresponding figures for E. laticeps (n=56) were 93% and 51.3 for larvae and 89% and 7.4 for nymphs, and for O. ventralis (n=3) were 67% and 22.5 for larvae and 100% and 21.3 for nymphs. Larvae and nymphs attached along the lateral grooves of O. ventralis. Nymphs attached mainly behind the ears and in the foreleg axillae whereas larvae mainly attached to these sites and on the hindlegs in Eumeces spp. Seasonally, both larvae and nymphs were recorded on lizards from April through October. A unimodal larval peak was recorded in May or June. Seasonal data for nymphs did not reveal any distinct peaks but small bimodal peaks in mean intensities may have occurred (one in early summer, the other in late summer)suggesting that some ticks complete their life cycle in one year, and others in two years, on St. Catherine's Island. Potential epidemiological consequences of these findings with respect to Lyme disease in the southeastern United States are briefly addressed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Acquired immunity to larvae of Amblyomma marmoreum and Ahebraeum by tortoises, guinea-pigs and guinea-fowl

A study of acquired resistance in guinea-pigs, guinea-fowl and tortoises to larvae of the ticks Amblyomma hebraeum Koch and A.marmoreum Koch (Acari: Ixodidae) showed that repeated infestations of the laboratory host resulted in a 29.3-49.4% reduction respectively in weight of engorged larvae. No resistance was induced in guinea-fowl, the natural host for larvae of both species. A small decline in the mean weight of engorged larvae was observed for both species of ticks after three successive infestations on tortoises. The reduction in weight was more pronounced in A.hebraeum (14.5%) which does not naturally feed on tortoises than for A.marmoreum (8.4%), a common tick on this host. The occurrence of acquired resistance in natural tick host relationships as opposed to unnatural tick host relationships is discussed.     

Biology and life cycle of <Emphasis Type="Italic">Amblyomma incisum</Emphasis> (Acari: Ixodidae)

Amblyomma incisum Neumann is a major tick species in the Atlantic Forest of Brazil. Tapir is the main host for adult ticks and a high aggressiveness of nymphs to humans has been reported. In this work data on the biology and life cycle of this tick species is presented for the first time. It was shown that horse is a suitable host for A. incisum adults and rabbit for larvae and nymphs. It was also shown that A. incisum is a big tick species (mean engorged female weight of 1.96 g) with a long life cycle which lasts 262.3 days when maintained at 27°C and 85% RH. These laboratory conditions were, however, inappropriate and egg hatching rate (1.2%) was very low. Nevertheless egg hatching of ticks in a forest patch increased considerably (72.2%) indicating that this A. incisum population is highly dependent on a forest-like environment.     

Ticks species (Ixodida) in the Summit Municipal Park and adjacent areas,Panama City,Panama

From September 2007 to September 2009, we studied the species of ticks present in the Summit Municipal Park. Ticks were extracted from zoo animals, free-living wild mammals and reptiles trapped, dead mammals on the roads and environment (ground and zoo burrows). A total of 2,649 ticks were collected: 2,167 immature stages (1,345 larvae and 822 nymphs) and 482 adults. Seventeen species were identified: Ornithodoros puertorricensis (Argasidae), Amblyomma auricularium, A. cajennense, A. calcaratum, A. dissimile, A. geayi, A. naponense, A. nodosum, A. oblongoguttatum, A. ovale, A. pecarium, A. sabanerae, A. tapirellum, A. varium, Ixodes luciae, Haemaphysalis juxtakochi and Rhipicephalus sanguineus (Ixodidae), representing 36% of the species reported in Panama. Amblyomma ovale was the species most commonly infesting animals from the zoo.     

Molecular Detection of Murine Herpesvirus 68 in Ticks Feeding on Free-living Reptiles

The MHV-68 (designed as Murid herpesvirus 4 (MuHV 4) strain 68) isolated from two rodents, Myodes glareolus and Apodemus flavicollis, is considered as a natural pathogen of free-living murid rodents. Recently, the detection of MHV antibodies in the blood of animals living in the same biotope as MHV-infected mice has suggested that ticks may have a role in the transmission of this pathogen. Ixodes ricinus is one the most abundant tick species in Europe known to transmit multiple pathogens causing human and animal diseases. In this study, nymphs and larvae feeding on 116 individuals of a temperate lizard species—the green lizard Lacerta viridis captured in the Slovak Karst National Park, were examined for MHV-68. The specific sequence of virion glycoprotein 150 was amplified in DNA individually isolated from I. ricinus ticks using single-copy sensitive nested polymerase chain reaction. MHV-68 was detected in ten of 649 nymphs and in five of 150 larvae, respectively. We found that 9.6% of green lizards fed at least one MHV-68-infected immature tick. Occurrence of MHV-68 within all ticks tested was 1.8%. This study is first to show that immature I. ricinus ticks feeding on free-living lizards in a Central European region could be infected with gammaherpesvirus (MHV-68), naturally infecting free-living murid rodents. Our results provide evidence supporting the hypothesis that ticks may play a mediating role in circulation of MHV-68 in nature.     

Amblyomma marmoreum on tortoises of southern province, Zambia

Reptiles from Southern Province, Zambia were captured and inspected for ticks. Seven of 18 tortoises (Geochelone pardalis) were infested by small numbers of adults and nymphs of Amblyomma marmoreum. Under such circumstances, the tick had little apparent effect on the host. None of the 13 specimens representing four species of snakes examined were infested with ticks.     

Drop off rhythm and survival periods of <Emphasis Type="Italic">Amblyomma lepidum</Emphasis> (Acari: Ixodidae) under field conditions

In this study, engorged Amblyomma lepidum ticks were found to drop off in two peaks, one in the morning and one in the evening. Most larvae and females engorged during the morning hours between 06.00 h and 10.00 h with a peak around 08.00 h, whereas the majority of the nymphs dropped in the evening between 18.00 h and 24.00 h with the peak around 22.00 h. Although the effect of time on drop-off patterns of the ticks was statistically significant (p≤ 0.001), there were no significant seasonal influences. Survival of unfed stages of A. lepidum was also studied and was found to increase from larvae to adult ticks. The longest survival periods of 10, 11 and 14 weeks were recorded during the wet season for larvae, nymphs and adults, respectively. It is concluded that environmental conditions required for survival of A. lepidum are optimal only during the wet season and that during other seasons the tick depends primarily on prevailing micro-climatic conditions for its survival.     

The effect of inflammatory and hypersensitive reactions,in response to the feeding of the tick Amblyomma variegatum,on the progression of experimental dermatophilosis infections

Initial infestations of Amblyomma variegatum larvae and nymphs, on rabbits and sheep respectively, produced inflammatory reactions in the host's skin; repeated infestations resulted in an increase in development of delayed type hypersensitive reactions. Dermatophilus congolensis cocci were applied in titrated doses to hosts at sites of inflammatory or hypersensitive reactions to ticks, and to control hosts with no exposure to ticks. We assessed the resulting infections for three weeks and found no significant difference between the infections on the three groups. We conclude that the local effects of the feeding of immature stages of this tick do not influence the pathogenesis of dermatophilosis.     

Isolation and characterization of a novel Borrelia group of tick-borne borreliae from imported reptiles and their associated ticks

The members of the genus Borrelia are transmitted by arthropods and known to be infectious to vertebrates. Here we found isolates and DNAs belonging to the Borrelia turcica and unknown Borrelia species from imported reptiles and their ectoparasites. The Borrelia strains were isolated from blood and multiple organs of exotic tortoises, and were experimentally infectious to captive-bred tortoises. These findings suggest that these tortoises may be a candidate as the reservoir host of the Borrelia species. In this study, the Borrelia strains were also isolated from and/or detected in hard-bodied ticks, Amblyomma ticks and Hyalomma ticks. In some of these ticks, immunofluorescence imaging analysis revealed that the Borrelia had also invaded into the tick salivary glands. Accordingly, these ticks were expected to be a potential vector of the Borrelia species. Sequencing analyses of both housekeeping genes ( flaB gene, gyrB gene and 16S rDNA gene) and 23S rRNA gene-16S rRNA gene intergenic spacer region revealed that these Borrelia strains formed a monophyletic group that was independent from two other Borrelia groups, Lyme disease Borrelia and relapsing fever Borrelia . From these results, the novel group of Borrelia comprises the third major group of arthropod-transmitted borreliae identified to date.