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PubMed2006

Coinfections acquired from ixodes ticks.

The pathogens that cause Lyme disease (LD), human anaplasmosis, and babesiosis can coexist in Ixodes ticks and cause human coinfections. Although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among Ixodes ticks remains largely unknown for the majority of geographic locations. The prevalence of dually infected Ixodes ticks appears highest among ticks from regions of North America and Europe where LD is endemic, with reported prevalences of < or =28%. In North America and Europe, the majority of tick-borne coinfections occur among humans with diagnosed LD. Humans coinfected with LD and babesiosis appear to have more intense, prolonged symptoms than those with LD alone. Coinfected persons can also manifest diverse, influenza-like symptoms, and abnormal laboratory test results are frequently observed. Coinfecting pathogens might alter the efficiency of transmission, cause cooperative or competitive pathogen interactions, and alter disease severity among hosts. No prospective studies to assess the immunologic effects of coinfection among humans have been conducted, but animal models demonstrate that certain coinfections can modulate the immune response. Clinicians should consider the likelihood of coinfection when pursuing laboratory testing or selecting therapy for patients with tick-borne illness.

Animals↗
PubMedDate not supplied

[The biodiversity dynamics of the causative agents of diseases transmitted by ticks in the genus Ixodes: an analysis of multiyear data].

Fauna of pathogen's met in the organism of the primary tick-borne disease vectors--Ixodes persulcatus Schulze and Ixodes ricinus (L.) was observed. Prevalence of Borrelia mono- and poly-infection in the I. persulcatus ticks within a season of the vector activity was analyzed and increase of the number of the dual infected specimens during the season was demonstrated. The first determination of Ehrlichia infected I. ricinus and I. persulcatus collected in the Baltic region of Russia was stated. The triple infection of Ixodes ticks in was proved: infection by the two species of Borrelia and Ehrlichia; infection by the three species of Borrelia and infection by the tick-borne encephalitis virus and two species of Borrelia. The first determination of the tick-borne encephalitis virus in I. ricinus in the recreational zone of Kaliningrad Province (Courland [correction of Curonian] Spit) was described. Dipetalonema sp. was detected in the St. Petersburg population of I. persulcatus. The prevalence of poly-infection among I. persulcatus ticks was stated.

Animals↗
PubMed2003

The occurrence of Borrelia burgdorferi sensu lato in the populations of Ixodes ricinus in forest areas of Szczecin during 2000-2001.

The aim of the present study was to determine the seasonal abundance of ticks, Ixodes ricinus and their infection frequency with spirochetes, Borrelia burgdorferi in wooded areas of the vicinity of the city of Szczecin during 2000-2001. The ticks were collected from April to October. Presence of Borrelia burgdorferi sensu lato was detected with the method of indirect immunofluorescence (IFA). The results showed differences in seasonal activity of ticks within the years of the study. In the year 2000 a single peak of their increased activity was noted, while in the year 2001 no significant changes in the population of Ixodes ricinus were recorded. Borrelia burgdorferi s. l. was detected in 2000 and 2001 in 11.6 % and 9.6 % of the specimens captured, respectively, which constituted a statistically significant difference. The highest level of infection of Ixodes ricinus in 2000 was observed in April (13.2 %), while in 2001 - in July (12.7 %). The differences in the prevalence value between respective months of both years were not statistically significant. The results of the present study indicate a high risk factor of acquiring Lyme borreliosis by humans and animals in wooded areas of the Szczecin vicinity.

Animals↗
PubMedDate not supplied

[New evidence for the detection of ehrlichia and anaplasma in ixodes ticks in Russia and Kazakhstan].

Polymerase chain reaction and sequence analysis were used to screen Ehrlichia and Anaplasma DNA in 900 specimens of Ixodes ticks of four genera (Dermacetor, Haemaphysalis, Ixodes, and Hyalomma) collected on 14 administrative territories of Russia and Kazakhstan. Anaplasma phagocytophilia DNA was detected and identified in Ixodes persulcatus ticks gathered in the Altai and Primorye Territories. Ehrlichia muris DNA was genotyped in the I. persulcatus ticks collected in the Tyumen, Omsk, and Novosibirsk Regions and the Altai Territory. Examining the Haemaphysalis concinna collected in the Primorye Territory revealed A. bovis DNA. The I. persulcatus ticks gathered in the Omsk Region were found to have "Ehrlichia-like "Schotti variant" DNA, Studying the ticks of the genera Dermatocentor and Hyalomma gathered in Russia and Kazakhstan failed to detect the representatives of the genera Anaplasma and Ehrlichia. The detection of A. phagocytophilia DNA in the I. persulcatus ticks in the Altai and Primorye territories and the serological verification of cases of human granulocytic anaplasmosis among patients with tick-borne infections in these territories lead to the conclusion that there are natural loci of this disease in West Siberia and the Far East of Russia.

Anaplasma↗
PubMedDate not supplied

[Ixodes ticks of the town of Cherkessk and its environs].

The paper presents the results of the studies made in 2002-2004 to examine the species-specific composition of Ixodes ticks. The ticks were gathered for a flag (155km routes being covered and 405 ticks being gathered); 48 dogs were examined, 320 ticks being gathered; 212 ticks were collected from human beings. The town dwellers' visit rates were grouped by ages and months. In the republic, Borreliae, the causative agents of Lyme borreliosis, were first isolated from Ixodes ricinus by darkground microscopy. Thus, there is one more available Lyme borreliosis focus. Enzyme immunoassay was used to study the sera from the dwellers bitten by ticks. Anti-M and anti-G antibodies were isolated. The paper presents the distribution of Ixodes ticks gathered for the flag and taken from dogs in accordance with the biotopes, establishes seasonal variations, and provides calculations of the abundance index on the dogs.

Adolescent↗
PubMed1982

Lyme disease: additional evidence of widespread distribution. Recognition of a tick-borne dermatitis-encephalitis-arthritis syndrome in an area of known ixodes tick distribution.

Lyme disease is a process of unknown etiology that has been linked to bites of ticks of the Ixodes ricinus complex. Central Minnesota is an area of known Ixodes dammini distribution. This case represents the first recognition of Lyme disease from this area. This case presented as a fluctuating meningoencephalitis with superimposed cranial neuropathy. The characteristic skin lesion, erythema chronicum migrans, was recognized by history, and oligoarticular arthritis subsequently developed. Physicians practicing in areas of known Ixodes tick distribution outside of the northeastern United States (coastal areas of Oregon and California, central Minnesota, northwestern Wisconsin, northwestern Utah, certain parts of ontario) should be alert to this disease and aware fo the variety of symptom complexes that are possible with it.

Adult↗
PubMed1986

Ultrastructural differences among spirochetes isolated from patients with Lyme disease and related disorders, and from Ixodes ricinus.

Previous studies on cells of strains B31 isolated in the U.S.A. from Ixodes dammini and strain G25 isolated in Sweden from Ixodes ricinus, showed that their ultrastructure was similar, but not identical. For this reason the studies were extended to spirochetes isolated directly from patients with Lyme disease and related disorders. Included in the present study were three strains isolated from skin, blood and spinal fluid, respectively, from patients with Lyme disease, two strains from patients with erythema chronicum migrans and one strain from a patient with acrodermatitis chronica atrophicans. Three additional strains isolated in Sweden from Ixodes ricinus were also studied. All spirochetes were examined after negative straining with 1% ammonium molybdate. The cells of each individual strain were identical except for one strain isolated from a tick. This isolate was found to consist of two morphologically different spirochetes. Comparison of morphological features of cells from various isolates revealed certain differences. The cells of the different strains could be divided into at least four groups for which cell size and shape as well as number of flagella varied. By morphological criteria, all cells were found to belong to the genus Borrelia.

Acrodermatitis↗
PubMed1995

Distribution of the Ixodes ricinus-like ticks of eastern North America.

We analyzed the geographic distribution of the Ixodes ricinus-like ticks in eastern North America by comparing the mitochondrial 16S rDNA sequences of specimens sampled directly from the field during the 1990s. Two distinct lineages are evident. The southern clade includes ticks from the southeastern and middle-eastern regions of the United States. The range of the northern clade, which appears to have been restricted to the northeastern region until the mid-1900s, now extends throughout the northeastern and middle-eastern regions. These phyletic units correspond to northern and southern taxa that have previously been assigned specific status as Ixodes dammini and Ixodes scapularis, respectively. The expanding range of I. dammini appears to drive the present outbreaks of zoonotic disease in eastern North America that include Lyme disease and human babesiosis.

Animals↗
PubMed1994

Vector competence of Ixodes pacificus and Dermacentor occidentalis (Acari: Ixodidae) for various isolates of Lyme disease spirochetes.

The vector competence of the western black-legged tick, Ixodes pacificus Cooley & Kohls, and the Pacific Coast tick, Dermacentor occidentalis Marx, for the Lyme disease spirochete (Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner) was compared. Rabbits, hamsters, and the deer mouse, Peromyscus maniculatus (Wagner), were injected with cultured spirochetes or infected tick-suspensions, or were fed upon by spirochete-infected ticks. Five of seven isolates used as inocula were reisolated from vertebrates with the ear-punch biopsy technique. Three isolates (CA4, 5, 7) that were infectious for both vertebrates and ticks possessed prominent low-molecular-weight protein bands that had relative mobilities of approximately 24-26 kd. The ability of ticks to acquire and maintain various inocula of B. burgdorferi was evaluated by feeding uninfected larvae xenodiagnostically on all three hosts 0-63 d postinjection. Low percentages (0-10.6%) of the I. pacificus and none of the D. occidentalis became infected. By contrast, 33% of I. pacificus and 40% of Ixodes scapularis Say (= I. dammini Spielman, Clifford, Piesman & Corwin) that fed on hamsters infected by tick-bite acquired and transstadially passed spirochetes; 10% of D. occidentalis fed on infected hamsters similarly acquired but did not maintain spirochetes. Ixodes pacificus nymphs efficiently transmitted B. burgdorferi to deer mice and a hamster. Feeding by one spirochete-infected nymph was sufficient to produce patent infections in each of five mice.

Animals↗
PubMed1991

Survey for Ixodes spp. and Borrelia burgdorferi in southeastern Wisconsin and northeastern Illinois.

Forested areas adjacent to Milwaukee, Wis., and Chicago, Ill., were investigated for rodents and ticks infected with Borrelia burgdorferi, the causative agent of Lyme disease. White-footed mice (Peromyscus leucopus or Peromyscus maniculatus), meadow voles (Microtus pennsylvanicus), and eastern chipmunks (Tamias striatus) were captured; and specimens from these animals were cultured for B. burgdorferi to define whether the midwestern Lyme disease area currently encompasses these large metropolitan centers. During 1988, B. burgdorferi was successfully cultured from the tissues of two M. pennyslvanicus voles captured from the Chicago area. However, no Ixodes spp. ticks were captured. None of 274 animals captured from sites I3 and 12 additional sites in Wisconsin and Illinois during the summer of 1989 were infected with B. burgdorferi or Ixodes spp. In addition, no ticks were recovered when the underbrush in 11 contiguous areas was flagged. Apparently, B. burgdorferi is rarely found in these areas because of the absence of the appropriate tick vectors. Further studies are needed to monitor the dispersal of B. burgdorferi-infected Ixodes dammini into this heavily populated midwestern region.

Animals↗
PubMed1994

Identification of spotted fever group rickettsiae isolated from Dermacentor marginatus and Ixodes ricinus ticks collected in Switzerland.

When 155 ticks collected in different regions of Switzerland were tested by the hemolymph test, 10.3% were found to contain spotted fever group rickettsiae. Six rickettsial isolates were made from Dermacentor marginatus ticks and three were made from Ixodes ricinus ticks. The polymerase chain reaction followed by restriction fragment length polymorphism analysis showed that the Dermacentor ticks were infected with Rickettsia length polymorphism analysis showed that the Dermacentor ticks were infected with Rickettsia slovaca and the Ixodes ticks were infected with a spotted fever group rickettsia. Microimmunofluorescence serologic type, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins, and Western blot assay with polyclonal mouse antisera confirmed the results and determined that the Ixodes were infected with R. helvetica, the only previously described Swiss rickettsia. However, an additional new strain that could not be isolated was detected in one I. ricinus by hemolymph test and provisionally characterized by enzymatic restriction of its amplified DNA.

Animals↗
PubMed1991

Differential detachment from resting hosts of replete larval and nymphal Ixodes ticks.

To determine whether replete subadult Ixodes ticks detach more frequently from resting than from active hosts, diverse rodents and lizards were caged in an apparatus designed to record the ticks' sites of detachment relative to the resting site of the host. Replete larval Ixodes ricinus and Ixodes dammini accumulated mainly beneath the resting places of the mice (Apodemus agrarius and Peromyscus leucopus) most frequently parasitized in nature. Although nymphal I. ricinus similarly detached where these mice rested, nymphal I. dammini detached more randomly. When lizards were used as hosts, both subadult stages of I. ricinus tended to detach away from their main resting sites; these ticks detached from squirrels more randomly. Detachment ratios for other rodent hosts, that are abundantly infested by the larvae of these ticks in nature (Apodemus flavicollis and Clethrionomys glareolus), could not be derived because nymphs generally failed to attach. Our observations are consistent with reports that both subadult stages of I. dammini, but not the adult, feed on the same kind of nest-dwelling hosts and that the host range of I. ricinus is less focused. Detachment of mouse-feeding larvae from resting mice promotes subsequent nymphal attachment to conspecific hosts, and the absence of such behavior among nymphs facilitates access of the resulting adults to deer.

Animals↗
PubMed1990

[Occurrence of Borrelia burgdorferi in Ixodes ricinus in The Netherlands].

In a 1989 surveillance to study the infection rate of Ixodes ricinus ticks with Borrelia burgdorferi, a total of 1838 nymphal and adult Ixodes ricinus ticks were collected from 20 locations in The Netherlands. By means of a culture method using modified Barbour-Kelly-Stoenner medium nymphs were examined in pools of 4 and adults were examined individually. With 63 out of 75 isolates propagation and serological identification were possible. All of these 63 isolates were identified as Borrelia burgdorferi by means of an indirect immunofluorescence assay. In nymphs the minimal infection rate was 2.4%. The rate of infection for adults was shown to be 14.3%. These results are in agreement with the percentages found by other investigators in West-Europe. In all locations examined Ixodes ricinus were found to be infected with Borrelia burgdorferi, although the infection rate varied. The results indicate that the infection is widespread among ticks in The Netherlands and the potential risk of acquiring Lyme borreliosis after a tick bite is serious.

Animals↗
PubMedDate not supplied

Ixodes ricinus spirochete and European erythema chronicum migrans disease.

From three endemic locations of erythema chronicum migrans disease in North Rhine-Westphalia, Germany, we recovered 19 isolates of a spirochete from Ixodes ricinus ticks. The infection rate in adult ticks was 16 percent. The isolated spirochete is immunologically related to the Ixodes dammini spirochete, Borrelia duttoni, and Treponema pallidum. Using indirect immunofluorescence, the sera of 90 patients with erythema chronicum migrans disease showed antibody titers against the isolated spirochete, which correlated with the clinical course. Similarly, antibodies were demonstrated in the sera of 21 patients with acrodermatitis chronica atrophicans. These results suggest an etiologic role for the Ixodes ricinus spriochete in European erythema chronicum migrans disease.

Antibodies, Bacterial↗
PubMedDate not supplied

[The characteristics of the distribution of the causative agent of Lyme disease and of the behavior of infected ticks of the genus Ixodes].

It is demonstrated that in the regions, where Ixodes persulcatus and I. ricinus are sympatric, the incidence and prevalence of Borrelia burgdorferi among the latter tick species is higher. In areas, where the Ixodes persulcatus population infected with Borrelia were met, the percent of infected I. ricinus was 3-4 times more and the number of detection of Borrelia-infected specimens was 9 times higher than in the regions, where I. persulcatus was absent. The hypothesis is proposed, that the tick I. persulcatus is a carrier and source of the most virulent and acarotropic Borrelia form. It is stated, that the reaction of the Borrelia-infected Ixodes ticks (I. persulcatus and I. ricinus) on the plant odour is changed. It is supposed that such changed plant odour-dependent behavior would be able to be enhancer of the I. persulcatus--I. ricinus Borrelia exchange process.

Animals↗
PubMed1999

Ixodes scapularis: effects of repeated infestations with pathogen-free nymphs on macrophage and T lymphocyte cytokine responses of BALB/c and C3H/HeN mice.

Schoeler, G. B., Manweiler, S. A., and Wikel, S. K. 1999. Ixodes scapularis: Effects of repeated infestations with pathogen-free nymphs on macrophage and T lymphocyte cytokine responses of BALB/c and C3H/HeN mice. Experimental Parasitology 92, 239-248. Ixodes scapularis is the principal vector in the United States of Borrelia burgdorferi, the causative agent of Lyme borreliosis, the human granulocytic ehrichiosis agent, and Babesia microti. Infestation with I. scapularis nymphs has previously been shown to modulate host T lymphocyte cytokine production. Tick-induced host immunomodulation is increasingly recognized as a contributing factor in successful transmission and/or establishment of tick-borne pathogens. This study was conducted to determine the effects of repeated infestations with pathogen-free I. scapularis nymphs on the production of the macrophage cytokines interleukin (IL)-1beta and tumor necrosis factor-alpha and the T lymphocyte cytokines IL-2, IL-4, IL-10, and interferon-gamma in both BALB/c and C3H/HeN mice. The pattern of T lymphocyte cytokine production was evaluated to determine if repeated tick infestation polarizes the immune response toward a Th-1 or Th-2 cytokine profile. Female BALB/c and C3H/HeN mice were infested one to four times with pathogen-free I. scapularis nymphs, with a 14-day tick-free period between each exposure. After each infestation, tick biology parameters were measured and macrophage and T lymphocyte cytokine production was assessed. Elaboration of T lymphocyte and macrophage cytokines was quantitated by antigen capture enzyme-linked immunosorbent assay. Acquired resistance to I. scapularis feeding was not developed by either mouse strain. Significant differences in cytokine production were observed between infested and noninfested mice, as well as between the two mouse strains, following tick infestation. Infestation of both strains with pathogen-free I. scapularis results in a polarization of the host immune response toward a Th-2, anti-inflammatory pattern, with a corresponding suppression of Th-1 responses.

Animals↗
PubMed1999

Ixodes ticks: serum species sensitivity of anticomplement activity.

Ixodid ticks feed for extended periods of up to 2 weeks or more. To complete engorgement, they must overcome their host's innate immune mechanisms of which the complement system is a major component. Using in vitro assays, salivary gland extracts of the ixodid ticks, Ixodes ricinus, I. hexagonus, and I. uriae, were shown to inhibit activity of the alternative pathway of complement. The ability of the different Ixodes species to inhibit complement activity varied with the animal species used as a complement serum source. Serum species sensitivity correlates to the reported host range of the tick species tested.

Animals↗
PubMed1995

Discriminating between Ixodes ticks by means of mitochondrial DNA sequences.

Ticks of the genus Ixodes have recently assumed prominence because they frequently serve as vectors of important zoonoses, including Lyme disease and babesiosis. The morphological characteristics that have been used in their identification often are ambiguous and are useful solely at a particular stage of development. Here we report the DNA sequence of the mitochondrially encoded 16S rRNA gene of nine different Ixodes ticks and an outgroup from another genus, Dermacentor. The sequences readily discriminate between these ticks. Samples of I. dammini from the northeastern and upper midwestern United States differ from southeastern I. scapularis at about 2% of the nucleotides. This difference is about half that separating other members of the I. ricinus group of species, but exceeds typical levels of intraspecific variation. Two major clades exist within the I. ricinus complex. One includes I. cookei, I. hexagonus, and I. angustus. The other includes I. persulcatus, I. pacificus, I. muris, I. ricinus, I. scapularis, and I. dammini. We conclude that mtDNA sequences are useful for unravelling the systematics of these important vectors of human disease.

Animals↗