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1.
Ann Agric Environ Med ; 26(4): 544-547, 2019 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-31885226

RESUMEN

INTRODUCTION: Ticks (Acari: Ixodida) are vectors and/or reservoirs of many pathogens, i.e. Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Babesia microti. These pathogens are ethiological agents of such diseases as Lyme borreliosis, human granulocytic anaplasmosis and human babesiosis. OBJECTIVE: The aim of the study was to evaluate the role of the Ixodes ricinus in the transmission of Borrelia burgdorferi sensu lato, Borrelia afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto, Anaplasma phagocytophilum and Babesia microti in Opolskie Province in Poland. MATERIAL AND METHODS: DNA from 222 ticks was isolated by the ammonia method. The pair of primers specific to the flagelline gene was used to detect of B. burgdorferi s. l. To detect of genospecies of this spirochete, three pairs of internal primers were used. In turn, two pairs of primers specific to the 16S rDNA gene and the 18S rRNA were used, respectively, for the detection of A. phagocytophilum and B. microti. Borrelia burgdorferi s. l., A. phagocytophilum, and B. microti were detected in 4.5%, 2.7% and 5.4% of examined ticks, respectively. RESULTS AND CONCLUSIONS: Of the ten ticks infected with B. burgdorferi s. l., B. afzelii was found in seven, undefinied genospecies in two, and mixed infection with B. afzelii and B. burgdorferi s. s. in one. The study demonstrated the potential risk of exposure of humans and animals to infections of B. burgdorferi s. l., A. phagocytophilum and B. microti in the examined area of Poland.


Asunto(s)
Anaplasma phagocytophilum/aislamiento & purificación , Vectores Artrópodos/microbiología , Vectores Artrópodos/parasitología , Babesia microti/aislamiento & purificación , Borrelia burgdorferi/aislamiento & purificación , Ixodes/microbiología , Ixodes/parasitología , Anaplasma phagocytophilum/genética , Animales , Babesia microti/genética , Babesiosis/parasitología , Babesiosis/transmisión , Borrelia burgdorferi/genética , Ehrlichiosis/microbiología , Ehrlichiosis/transmisión , Humanos , Ixodes/genética , Ixodes/fisiología , Enfermedad de Lyme/microbiología , Enfermedad de Lyme/transmisión , Polonia
2.
Parasitol Res ; 118(12): 3205-3216, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31720842

RESUMEN

In 2014, a new tick species, Ixodes inopinatus, was described, which is closely related to Ixodes ricinus. So far, I. inopinatus has been found in Tunisia, Morocco, Spain, Portugal, Romania, Austria, and southern Germany. No data is yet available regarding occurrence of I. inopinatus in northern Germany and the potential role of I. inopinatus as a vector for tick-borne pathogens. Therefore, 3845 DNA samples from Ixodes ticks collected for prevalence studies on Borrelia spp., Rickettsia spp., and Anaplasma phagocytophilum during the years 2010-2015 in the northern German cities of Hamburg and Hanover were differentiated into I. ricinus or I. inopinatus by sequencing a part of the 16S rRNA gene. In total, 4% (137/3845) of the sequenced ticks were assigned to the species I. inopinatus and 96% (3708/3845) to I. ricinus. The prevalence of Borrelia spp., Rickettsia spp., and A. phagocytophilum DNA in I. inopinatus was 34% (46/137), 46% (63/137), and 3% (4/137), respectively, whereas the prevalence of these bacteria in I. ricinus was 25% (919/3708), 47% (1729/3708), and 4% (135/3708), respectively. Compared with I. ricinus, significantly more I. inopinatus ticks tested positive for Borrelia. To the best of our knowledge, this is the first report of I. inopinatus in northern Germany. Detection of the DNA of Borrelia spp., Rickettsia spp., and A. phagocytophilum in questing I. inopinatus indicates a potential role of this tick species as a vector of these pathogens, which needs to be confirmed by transmission experiments.


Asunto(s)
Anaplasma phagocytophilum/genética , Vectores Arácnidos/microbiología , Borrelia/genética , Ixodes/microbiología , Rickettsia/genética , Animales , Vectores Arácnidos/clasificación , Vectores Arácnidos/genética , Alemania/epidemiología , Ixodes/clasificación , Ixodes/genética , ARN Ribosómico 16S/genética , Enfermedades por Picaduras de Garrapatas/epidemiología
3.
Cent Eur J Public Health ; 27(3): 235-238, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31580560

RESUMEN

OBJECTIVES: Lyme disease (Lyme borreliosis) is a transmissible infection, common in the temperate climate zones. It is caused by a group of spirochetal bacteria known as Borrelia burgdorferi sensu lato complex. The aim of the present work was to investigate the incidence rate of borreliosis in different regions of Bulgaria and to identify possible risk factors for its occurrence. METHODS: National and regional borreliosis incidence rates for 2009-2018 were obtained from the public database of the National Centre of Public Health and Analyses. Their association with some socio-demographic variables and the geographic location (south or north) of the regions was tested with Spearman's correlation analysis and simple linear regression. RESULTS: The mean annual incidence for the last 10 years (2009-2018) in Bulgaria was 6.9 (range 4.1-11.6) cases per 100,000 inhabitants. We found that the Lyme disease was highly fluctuating at regional level with incidence rates varied from 0.3 to 30.9 per 100,000 inhabitants. Several regions showed significantly higher endemicity for the disease. Socio-demographic factors were not found to be important for Lyme disease frequency while the geographic location in the north part of the country was a significant risk factor for it. CONCLUSIONS: Lyme disease is a serious health risk in Bulgaria especially in its northern part - regions on the north are the most vulnerable to a higher incidence of the disease.


Asunto(s)
Borrelia burgdorferi , Ixodes , Enfermedad de Lyme , Animales , Bulgaria , Estudios Epidemiológicos , Humanos , Incidencia , Ixodes/microbiología , Enfermedad de Lyme/epidemiología
4.
Parasit Vectors ; 12(1): 434, 2019 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-31492171

RESUMEN

BACKGROUND: The density of questing ticks infected with tick-borne pathogens is an important parameter that determines tick-borne disease risk. An important factor determining this density is the availability of different wildlife species as hosts for ticks and their pathogens. Here, we investigated how wildlife communities contribute to tick-borne disease risk. The density of Ixodes ricinus nymphs infected with Borrelia burgdorferi (sensu lato), Borrelia miyamotoi, Neoehrlichia mikurensis and Anaplasma phagocytophilum among 19 forest sites were correlated to the encounter probability of different vertebrate hosts, determined by encounter rates as measured by (camera) trapping and mathematical modeling. RESULT: We found that the density of any tick life stage was proportional to the encounter probability of ungulates. Moreover, the density of nymphs decreased with the encounter probability of hare, rabbit and red fox. The density of nymphs infected with the transovarially-transmitted B. miyamotoi increased with the density of questing nymphs and the encounter probability of bank vole. The density of nymphs infected with all other pathogens increased with the encounter probability of competent hosts: bank vole for Borrelia afzelii and N. mikurensis, ungulates for A. phagocytophilum and blackbird for Borrelia garinii and Borrelia valaisiana. The negative relationship we found was a decrease in the density of nymphs infected with B. garinii and B. valaisiana with the encounter probability of wood mouse. CONCLUSIONS: Only a few animal species drive the densities of infected nymphs in forested areas. There, foxes and leporids have negative effects on tick abundance, and consequently on the density of infected nymphs. The abundance of competent hosts generally drives the abundances of their tick-borne pathogen. A dilution effect was only observed for bird-associated Lyme spirochetes.


Asunto(s)
Enfermedades de los Animales/epidemiología , Biota , Bosques , Ixodes/microbiología , Infestaciones por Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/veterinaria , Vertebrados/parasitología , Anaplasma/aislamiento & purificación , Animales , Borrelia/aislamiento & purificación , Ehrlichia/aislamiento & purificación , Ixodes/crecimiento & desarrollo , Densidad de Población , Medición de Riesgo , Infestaciones por Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/epidemiología
5.
Klin Lab Diagn ; 64(7): 424-429, 2019.
Artículo en Ruso | MEDLINE | ID: mdl-31408595

RESUMEN

Molecular genetic monitoring of natural focal of tick-borne infections in the epidemic season of 2018 revealed infectiousness of ixodid ticks causative agents of tick-borne encephalitis (0.58% of cases), Lyme disease (31% of cases), human monocytic ehrlichiosis (1.6% of cases) and granulocytic anaplasmosis (3.9% of cases) is registered and also co-infections of ticks by these infections (2.9% of cases) is revealed in natural and anthropourgic foci (B. burgdorferi s.l.+A. phagocytophilum, B. burgdorferi s.l.+E. chaffeensis/E. muris and B. burgdorferi s.l.+tick-borne encephalitis virus). The major epidemiological importance of ticks of the species I. persulcatus is found, their share being 87,6%. The majority of patients being bitten by a tick were from the southern and southeast areas of Primorye. Contamination of ticks with Borrelia was revealed not only in I. persulcatus, but also in ticks of the Haemaphysalis and Dermacentor. The infectiousness of ticks of B. burgdorferi s.l. (42,3%), tick-borne encephalitis virus (7,7%) and A. phagocytophilum (15,4%) was highest on Russky Island.


Asunto(s)
Ixodes/microbiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Animales , Ehrlichiosis/epidemiología , Monitoreo Epidemiológico , Humanos , Enfermedad de Lyme/epidemiología , Biología Molecular , Federación de Rusia
6.
Ticks Tick Borne Dis ; 10(6): 101254, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31327746

RESUMEN

Ixodes persulcatus and Ixodes pavlovskyi ticks, two closely related species of the I. ricinus - I. persulcatus group, are widely distributed in the southern part of Western Siberia. Recently, the existence of natural hybrids of I. persulcatus and I. pavlovskyi ticks has been demonstrated. The aim of this study was to evaluate the abundance of I. persulcatus/pavlovskyi hybrids in several locations with different ratios of parental tick species and to investigate the prevalence and genetic variability of a wide range of infectious agents in these hybrids compared to the parental tick species. Natural hybrids of I. persulcatus and I. pavlovskyi ticks were identified in all examined locations in Altai and Novosibirsk, Western Siberia, Russia. The abundance of hybrids varied from 7% to 40% in different locations and was maximal in a location with similar proportions of I. persulcatus and I. pavlovskyi ticks. For the first time, it was shown that hybrids can be infected with the same agents as their parental tick species: tick-borne encephalitis and Kemerovo viruses, Borrelia afzelii, Borrelia bavariensis, Borrelia garinii, Borrelia miyamotoi, Rickettsia helvetica, Rickettsia raoultii, Rickettsia sibirica, "Candidatus Rickettsia tarasevichiae", Anaplasma phagocytophilum, Ehrlichia muris, "Candidatus Neoehrlichia mikurensis", and Babesia microti. The prevalence of most bacterial agents in hybrids was intermediate compared to their parental tick species. Most genetic variants of the identified agents have been previously found in the parental tick species. Wide distribution of I. persulcatus/pavlovskyi natural hybrids implies that I. persulcatus, I. pavlovskyi and their hybrids coexist in all I. persulcatus - I. pavlovskyi sympatric areas.


Asunto(s)
Hibridación Genética , Ixodes/microbiología , Ixodes/parasitología , Anaplasmataceae/clasificación , Anaplasmataceae/aislamiento & purificación , Animales , Secuencia de Bases , Grupo Borrelia Burgdorferi/clasificación , Grupo Borrelia Burgdorferi/aislamiento & purificación , Virus de la Encefalitis Transmitidos por Garrapatas/clasificación , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Femenino , Ixodes/genética , Masculino , Orbivirus/clasificación , Orbivirus/aislamiento & purificación , Filogenia , Rickettsia/clasificación , Rickettsia/aislamiento & purificación , Alineación de Secuencia , Siberia
7.
Ticks Tick Borne Dis ; 10(6): 101241, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31279737

RESUMEN

Fifty nymphal Ixodes ricinus ticks collected in Alsace, France, identified by morphological criteria and using MALDI-TOF MS, were tested by PCR to detect tick-associated bacteria and protozoan parasites. Seventy percent (35/50) of ticks contained at least one microorganism; 26% (9/35) contained two or more species. Several human pathogens were identified including Borrelia burgdorferi s.s. (4%), Borrelia afzelii (2%), Borrelia garinii (2%), Borrelia valaisiana (4%), Borrelia miyamotoi (2%), Rickettsia helvetica (6%) and "Babesia venatorum" (2%). Bartonella spp. (10%) and a Wolbachia spp. (8%) were also detected. The most common co-infections involved Anaplasmataceae with Borrelia spp. (4%), Anaplasmataceae with Bartonella spp. (6%) and Anaplasmataceae with Rickettsia spp. (6%). Co-infection involving three different groups of bacteria was seen between bacteria of the family Anaplasmataceae, Borrelia spp. and Bartonella spp. (2%). Results highlight the panel of infectious agents carried by Ixodes ricinus. Co-infection suggests the possibility of transmission of more than one pathogen to human and animals during tick blood feeding.


Asunto(s)
Ixodes/microbiología , Ixodes/parasitología , Animales , Babesia/clasificación , Babesia/aislamiento & purificación , Bartonella/clasificación , Bartonella/aislamiento & purificación , Borrelia/aislamiento & purificación , Francia , Ixodes/crecimiento & desarrollo , Ninfa/crecimiento & desarrollo , Ninfa/microbiología , Ninfa/parasitología , Filogenia , Reacción en Cadena de la Polimerasa , Rickettsia/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Wolbachia/aislamiento & purificación
8.
Parasit Vectors ; 12(1): 338, 2019 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-31288866

RESUMEN

The taiga tick, Ixodes persulcatus, has previously been limited to eastern Europe and northern Asia, but recently its range has expanded to Finland and northern Sweden. The species is of medical importance, as it, along with a string of other pathogens, may carry the Siberian and Far Eastern subtypes of tick-borne encephalitis virus. These subtypes appear to cause more severe disease, with higher fatality rates than the central European subtype. Until recently, the meadow tick, Dermacentor reticulatus, has been absent from Scandinavia, but has now been detected in Denmark, Norway and Sweden. Dermacentor reticulatus carries, along with other pathogens, Babesia canis and Rickettsia raoultii. Babesia canis causes severe and often fatal canine babesiosis, and R. raoultii may cause disease in humans. We collected 600 tick nymphs from each of 50 randomly selected sites in Denmark, southern Norway and south-eastern Sweden in August-September 2016. We tested pools of 10 nymphs in a Fluidigm real time PCR chip to screen for I. persulcatus and D. reticulatus, as well as tick-borne pathogens. Of all the 30,000 nymphs tested, none were I. persulcatus or D. reticulatus. Our results suggest that I. persulcatus is still limited to the northern parts of Sweden, and have not expanded into southern parts of Scandinavia. According to literature reports and supported by our screening results, D. reticulatus may yet only be an occasional guest in Scandinavia without established populations.


Asunto(s)
Dermacentor/fisiología , Ixodes/fisiología , Distribución Animal , Animales , Vectores Artrópodos/microbiología , Vectores Artrópodos/parasitología , Babesiosis/prevención & control , Dermacentor/microbiología , Dermacentor/parasitología , Perros , Encefalitis Transmitida por Garrapatas/prevención & control , Monitoreo Epidemiológico , Pradera , Ixodes/microbiología , Ixodes/parasitología , Noruega/epidemiología , Ninfa/virología , Países Escandinavos y Nórdicos/epidemiología , Suecia/epidemiología , Infestaciones por Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/prevención & control
9.
Ticks Tick Borne Dis ; 10(6): 101255, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31280947

RESUMEN

The occurrence of Borrelia garinii in seabird ticks, Ixodes uriae, associated with different species of colonial seabirds has been studied since the early 1990s. Research on the population structure of this bacterium in ticks from seabird colonies in the northeastern Atlantic Ocean has revealed admixture between marine and terrestrial tick populations. We studied B. garinii genetic diversity and population structure in I. uriae collected from seabird colonies in the northwestern Atlantic Ocean, in Newfoundland and Labrador, Canada. We applied a multi-locus sequence typing (MLST) scheme to B. garinii found in ticks from four species of seabirds. The B. garinii strains found in this seabird colony ecosystem were diverse. Some were very similar to strains from Asia and Europe, including some obtained from human clinical samples, while others formed a divergent group specific to this region of the Atlantic Ocean. Our findings highlight the genetic complexity of B. garinii circulating in seabird ticks and their avian hosts but also demonstrate surprisingly close connections between B. garinii in this ecosystem and terrestrial sources in Eurasia. Genetic similarities among B. garinii from seabird ticks and humans indicate the possibility that B. garinii circulating within seabird tick-avian host transmission cycles could directly, or indirectly via connectivity with terrestrial transmission cycles, have consequences for human health.


Asunto(s)
Grupo Borrelia Burgdorferi/genética , Charadriiformes/parasitología , Variación Genética , Ixodes/microbiología , Animales , Tipificación de Secuencias Multilocus , Terranova y Labrador
10.
Ticks Tick Borne Dis ; 10(6): 101256, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31255535

RESUMEN

Ehrlichia spp. are obligatory intracellular microorganisms that infect hematopoietic, endothelial or blood cells of mammals. Ticks are the only vectors of these agents in nature. To date, the role of birds and their associated ticks as reservoirs of ehrlichiae remains almost unexplored. In this study, we performed a molecular screening for bacteria of Anaplasmataceae family in samples of spleen (n = 72) and lung (n = 17), recovered from 72 carcasses of Magellanic penguins (Spheniscus magellanicus) in Brazil and Chile. One apparently unengorged tick (Ixodes uriae) was also collected while wandering upon one of the carcasses and submitted to molecular analyses as well. Through conventional and nested PCR protocols three genes (16S rRNA, dsb and groEL) of a new Ehrlichia sp. were partially characterized upon organs of three penguins and in the tick coming from Magdalena Island (Chile). First matches after BLASTn comparisons showed that our sequences share 99.4% (16S rRNA), 94.6% (groEL) and 79.3% (dsb) of identity with "Candidatus Ehrlichia ornithorhynchi", Ehrlichia sp. NS101 and Ehrlichia canis CCZ, respectively. Matrixes of genetic distance including other representatives of the Ehrlichia genus point a 99.4%, 94.0%, and 80.0% of identity with 16S rRNA, groEL and dsb genes from Ehrlichia sp. It25, Ehrlichia sp. NS101, and Ehrlichia chaffeensis San Louis, respectively. A Bayesian phylogenetic analysis of Anaplasmataceae 16S rRNA gene places the detected Ehrlichia sp. into a group with Ehrlichia sp. BAT and Ehrlichia sp. Natal. Although depicting different topologies, Bayesian unrooted phylogenetic trees constructed for groEL and dsb genes position this Ehrlichia sp. into well-supported branches, which reinforces the finding of a new taxon. For the moment, any pathogenic effect of this new Ehrlichia sp. on penguins is still unknown. However, this fact becomes important to assess from a conservation point of view since populations of Magellanic penguins are currently threatened and in an ongoing decrease.


Asunto(s)
Ehrlichia/clasificación , Ixodes/microbiología , Spheniscidae/microbiología , Animales , Proteínas Bacterianas/análisis , Chaperonina 60/análisis , Chile , Ehrlichia/fisiología , Femenino , Filogenia , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis
11.
Sante Publique ; S1(HS): 51-63, 2019 May 13.
Artículo en Francés | MEDLINE | ID: mdl-31210491

RESUMEN

Epidemiological evidence for tick-borne infections, particularly those related to Lyme borreliosis, is heterogeneous. Lyme borreliosis is a tick-born zoonosis transmitted by ticks of the genus Ixodes ricinus. After tick bite, the risk of transmission of an infectious agent remains low, most often represented by Borrelia burgdorferi sensu lato; co-infections in Humans by several different infectious agents (bacterial, viral or parasitic) are possible but a priori rare. In addition, besides well-known tick-borne pathogens, new species or gender of micro-organisms are regularly described in ticks but their pathogenicity in human pathology is not described or not yet established. The clinical presentation of Lyme borreliosis is varied, with localized and disseminated forms occurring long ago after tick bite, making diagnosis sometimes difficult. The natural course of Lyme borreliosis is insufficiently known because of recommendations of antibiotherapy in case of illness; however, some historical studies seem reassuring with possible spontaneous healing and seemingly minor sequelae. The diagnosis of disseminated forms requires paraclinical examinations, in first place serology, whose sensitivity increases with time of evolution of borreliosis; this is all the more interesting as the disseminated forms are of more difficult clinical diagnosis. After antibiotherapy, the clinical course is good, the sequelae remain possible especially in case of late diagnosis or late disseminated form; however, their frequency remains unknown.


Asunto(s)
Ixodes/microbiología , Enfermedad de Lyme/epidemiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Animales , Francia/epidemiología , Humanos , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/microbiología
12.
Parasit Vectors ; 12(1): 328, 2019 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-31253201

RESUMEN

BACKGROUND: Anaplasma phagocytophilum is currently regarded as a single species. However, molecular studies indicate that it can be subdivided into ecotypes, each with distinct but overlapping transmission cycle. Here, we evaluate the interactions between and within clusters of haplotypes of the bacterium isolated from vertebrates and ticks, using phylogenetic and network-based methods. METHODS: The presence of A. phagocytophilum DNA was determined in ticks and vertebrate tissue samples. A fragment of the groEl gene was amplified and sequenced from qPCR-positive lysates. Additional groEl sequences from ticks and vertebrate reservoirs were obtained from GenBank and through literature searches, resulting in a dataset consisting of 1623 A. phagocytophilum field isolates. Phylogenetic analyses were used to infer clusters of haplotypes and to assess phylogenetic clustering of A. phagocytophilum in vertebrates or ticks. Network-based methods were used to resolve host-vector interactions and their relative importance in the segregating communities of haplotypes. RESULTS: Phylogenetic analyses resulted in 199 haplotypes within eight network-derived clusters, which were allocated to four ecotypes. The interactions of haplotypes between ticks, vertebrates and geographical origin, were visualized and quantified from networks. A high number of haplotypes were recorded in the tick Ixodes ricinus. Communities of A. phagocytophilum recorded from Korea, Japan, Far Eastern Russia, as well as those associated with rodents had no links with the larger set of isolates associated with I. ricinus, suggesting different evolutionary pressures. Rodents appeared to have a range of haplotypes associated with either Ixodes trianguliceps or Ixodes persulcatus and Ixodes pavlovskyi. Haplotypes found in rodents in Russia had low similarities with those recorded in rodents in other regions and shaped separate communities. CONCLUSIONS: The groEl gene fragment of A. phagocytophilum provides information about spatial segregation and associations of haplotypes to particular vector-host interactions. Further research is needed to understand the circulation of this bacterium in the gap between Europe and Asia before the overview of the speciation features of this bacterium is complete. Environmental traits may also play a role in the evolution of A. phagocytophilum in ecotypes through yet unknown relationships.


Asunto(s)
Anaplasma phagocytophilum/genética , Biota , Evolución Molecular , Filogenia , Anaplasma phagocytophilum/aislamiento & purificación , Animales , Asia , Chaperonina 60/genética , Ecotipo , Europa (Continente) , Geografía , Haplotipos , Ixodes/microbiología , Vertebrados/microbiología
13.
Parasit Vectors ; 12(1): 289, 2019 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-31174589

RESUMEN

BACKGROUND: Tick selenoproteins are involved in regulating oxidative and endoplasmic reticulum stress during prolonged tick feeding on mammalian hosts. How selenoproteins are activated upon tick-borne pathogen infection is yet to be defined. METHODS: To examine the functional role of selenoprotein K in Borrelia burgdorferi infection within the tick host Ixodes scapularis, RNA interference (RNAi)-based gene silencing was performed. RESULTS: Selenoprotein K is an endoplasmic reticulum (ER)-resident protein and a component of the ERAD complex involved in ER homeostasis. A qRT-PCR assay revealed the significant upregulation of selenogene K (selenoK) expression in B. burgdorferi-infected tick tissues. Silencing of the selenoK transcript significantly depleted B. burgdorferi copies within the infected tick tissues. Upon selenoK knockdown, another component of the ERAD complex, selenoprotein S (selenoS), was significantly upregulated, suggesting a compensatory mechanism to maintain ER homeostasis within the tick tissues. Knockdown of selenoK also upregulated ER stress-related unfolded protein response (UPR) pathway components, ATF6 and EIF2. CONCLUSIONS: The exact mechanisms that contribute to depletion of B. burgdorferi upon selenoK knockdown is yet to be determined, but this study suggests that selenoK may play a vital role in the survival of B. burgdorferi within the tick host.


Asunto(s)
Proteínas de Artrópodos/genética , Borrelia burgdorferi/fisiología , Ixodes/genética , Enfermedad de Lyme , Selenoproteínas/genética , Animales , Vectores de Enfermedades , Retículo Endoplásmico/química , Femenino , Ixodes/microbiología , Masculino , Interferencia de ARN , Reacción en Cadena en Tiempo Real de la Polimerasa , Respuesta de Proteína Desplegada/genética , Regulación hacia Arriba
14.
Med Vet Entomol ; 33(4): 512-520, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31173386

RESUMEN

Spirochetes from the Borrelia burgdorferi sensu lato (s.l.). (Spirochaetales: Spirochaetaceae) species complex, including the causative agents of Lyme borreliosis, have been isolated from ticks, vertebrate reservoirs and humans. Previous analyses based on direct molecular detection in ticks indicated a considerable diversity of B. burgdorferi s.l. complex in Serbia. The present study aimed (a) to isolate borrelia strains from Serbia; (b) to determine their genotypic characteristics; and (c) to establish a collection of viable B. burgdorferi s.l. strains for further biological, ecological and genetic studies. For the present study, 231 adult Ixodes ricinus (Ixodida: Ixodidae) ticks from 16 ecologically different localities in Serbia were individually processed to cultivate B. burgdorferi s.l. This led to the isolation of 36 strains. A hbb gene quantitative real-time polymerase chain reaction (PCR) based on melting temperature determination and ospA gene sequencing were used to genotype the isolated spirochetes. The species identified based on the hbb gene real-time PCR were: Borrelia lusitaniae (44.4%), Borrelia afzelii (36.1%), Borrelia garinii (13.9%) and Borrelia valaisiana (5.6%), whereas the ospA sequence analysis revealed the occurrence of Borrelia bavariensis. This is the first report of the isolation of B. lusitaniae, B. garinii, B. bavariensis and B. valaisiana strains in Serbia.


Asunto(s)
Grupo Borrelia Burgdorferi/fisiología , Genotipo , Ixodes/microbiología , Microbiota , Animales , Grupo Borrelia Burgdorferi/clasificación , Grupo Borrelia Burgdorferi/genética , Grupo Borrelia Burgdorferi/aislamiento & purificación , Enfermedad de Lyme , Serbia , Spirochaetales/genética , Spirochaetales/aislamiento & purificación , Spirochaetales/fisiología
15.
Ticks Tick Borne Dis ; 10(5): 1070-1077, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31176662

RESUMEN

A wide range of arthropod species harbour bacterial endosymbionts in various tissues, many of them playing important roles in the fitness and biology of their hosts. In several cases, many different symbionts have been reported to coexist simultaneously within the same host and synergistic or antagonistic interactions can occur between them. While the associations with endosymbiotic bacteria have been widely studied in many insect species, in ticks such interactions are less investigated. The females and immatures of Ixodes ricinus (Ixodidae), the most common hard tick in Europe, harbour the intracellular endosymbiont "Candidatus Midichloria mitochondrii" with a prevalence up to 100%, suggesting a mutualistic relationship. Considering that the tissue distribution of a symbiont might be indicative of its functional role in the physiology of the host, we investigated M. mitochondrii specific localization pattern and the corresponding abundance in selected organs of I. ricinus females. We paired these experiments with in silico analysis of the metabolic pathways of M. mitochondrii, inferred from the available genome sequence, and additionally compared the presence of these pathways in seven other symbionts commonly harboured by ticks to try to obtain a comparative understanding of their biological effects on the tick hosts. M. mitochondrii was found to be abundant in ovaries and tracheae of unfed I. ricinus, and in ovaries, Malpighian tubules and salivary glands of semi-engorged females. These results, together with the in silico metabolic reconstruction allow to hypothesize that the bacterium could play multiple tissue-specific roles in the host, both enhancing the host fitness (supplying essential nutrients, enhancing the reproductive fitness, helping in the anti-oxidative defence, in the energy production and in the maintenance of homeostasis and water balance) and/or for ensuring its presence in the host population (nutrients acquisition, vertical and horizontal transmission). The ability of M. mitochondrii to colonize different tissues allows to speculate that distinctive sub-populations may display different specializations in accordance with tissue tropism. Our hypotheses should be corroborated with future nutritional and physiological experiments for a better understanding of the mechanisms underlying this symbiotic interaction.


Asunto(s)
Genoma Bacteriano , Ixodes/microbiología , Redes y Vías Metabólicas , Rickettsiales/fisiología , Simbiosis , Tropismo Viral , Animales , Simulación por Computador , Femenino , Italia , Rickettsiales/genética , Rickettsiales/metabolismo
16.
Ticks Tick Borne Dis ; 10(5): 1060-1065, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31176664

RESUMEN

During its lifecycle, the generalist Ixodes ricinus takes up three blood meals from a wide selection of vertebrate hosts, some of which are reservoirs for multiple vector-associated pathogens. Since I. ricinus also readily bites humans, pets, and livestock, these hosts are at risk of becoming infected with more than one tick-borne pathogen. Multiple tick-borne infections are a public health concern, since they may increase diversity and duration of symptoms and complicate differential diagnosis and therapy. We used an existing Fluidigm real-time PCR chip to identify the minimum risk of exposure to infected/co-infected ticks in Denmark. We screened 509 nymphs and 504 adult female I. ricinus ticks for 17 different vector-associated pathogenic agents. The questing ticks were collected by flagging during the same season in two consecutive years in Grib forest in the capital region of Copenhagen. Overall, 19.1% of the nymphs and 52.2% of the adult female ticks harbored at least one zoonotic pathogen. The main agents were Borrelia spp., Anaplasma phagocytophilum and Rickettsia helvetica, while Candidatus Neoehrlichia mikurensis and Babesia venatorum both were present in less than 1% of the ticks. In 3.5% of the nymphs and 12.3% of adults we found more than one tick-borne pathogen. Of these, 15% were potentially triple or quadruple infections. Whereas mixed infections with Borrelia were equally distributed among both life stages, the adult ticks hosted 84.5% of the co-infections with different species of tick-borne pathogens, chiefly involving Borrelia species in combination with either R. helvetica or A. phagocytophilum. Statistical analyses indicated non-random co-occurrence of Borrelia spielmanii/Borrelia garinii in both life stages and B. garinii/Borrelia afzelii and B. garinii/Borrelia valaisiana in the nymphs. Although the overall prevalence of ticks hosting more than one infection only constituted 7.9% at the particular site investigated in this study, our results still underline that co-infections should be considered in diagnosis and treatment of tick-borne diseases in northern Europe.


Asunto(s)
Anaplasma phagocytophilum/aislamiento & purificación , Babesia/aislamiento & purificación , Borrelia/aislamiento & purificación , Ixodes/microbiología , Ixodes/parasitología , Rickettsia/aislamiento & purificación , Animales , Dinamarca , Femenino , Bosques , Ixodes/crecimiento & desarrollo , Ninfa/crecimiento & desarrollo , Ninfa/microbiología , Ninfa/parasitología
17.
Transpl Infect Dis ; 21(4): e13129, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31215144

RESUMEN

Human granulocytic anaplasmosis (HGA), caused by Anaplasma phagocytophilum, is an emerging tick-borne disease. It is spread by the black-legged deer tick Ixodes scapularis that serves as the vector for six human pathogens. HGA is still rarely reported in solid organ transplant recipients. In solid organ transplant recipients, orchitis has been reported secondary to chickenpox, tuberculosis and infections due to Listeria monocytogenes and Nocardia asteroides. Orchitis as a presenting feature of HGA infection has only been reported in animals. We present a unique case of a renal transplant recipient with HGA that presented as orchitis. We also compare the clinical presentation and laboratory findings of our patient with other cases of HGA in transplant recipients. To the best of our knowledge, our patient is one of the first cases of A phagocytophilum mono-infection causing a classical presentation of orchitis in a transplant patient.


Asunto(s)
Anaplasmosis/diagnóstico , Trasplante de Riñón/efectos adversos , Orquitis/microbiología , Receptores de Trasplantes , Anciano , Anaplasma phagocytophilum , Anaplasmosis/tratamiento farmacológico , Animales , Antibacterianos/uso terapéutico , Doxiciclina/uso terapéutico , Humanos , Ixodes/microbiología , Masculino
18.
Ticks Tick Borne Dis ; 10(5): 1124-1134, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31204044

RESUMEN

Lyme disease is a common tick-borne infection caused by the spirochete Borrelia burgdorferi sensu stricto (s.s.). B. burgdorferi s.s. may utilize chemotaxis, the directional migration towards or away from a chemical stimulus, for transmission, acquisition, and infection. However, the specific signals recognized by the spirochete for these events have not been defined. In this study, we identify an Ixodes scapularis salivary gland protein, Salp12, that is a chemoattractant for the spirochete. We demonstrate that Salp12 is expressed in the I. scapularis salivary glands and midgut and expression is not impacted by B. burgdorferi s.s. infection. Knockdown of Salp12 in the salivary glands or passive immunization against Salp12 reduces acquisition of the spirochete by ticks but acquisition is not completely prevented. Knockdown does not impact transmission of B. burgdorferi s.s. This work suggests a new role for chemotaxis in acquisition of the spirochete and suggests that recognition of Salp12 contributes to this phenomenon.


Asunto(s)
Vectores Arácnidos/microbiología , Proteínas de Artrópodos/fisiología , Borrelia burgdorferi/fisiología , Quimiotaxis , Ixodes/microbiología , Animales , Enfermedad de Lyme/transmisión , Glándulas Salivales/fisiología
19.
Ticks Tick Borne Dis ; 10(4): 918-923, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31056486

RESUMEN

A rickettsial isolate was obtained from a partially engorged Ixodes pacificus female, which was collected from Humboldt County, California. The isolate was provisionally named Rickettsia endosymbiont Ixodes pacificus (REIP). The REIP isolate displayed the highest nucleotide sequence identity to Rickettsia species phylotype G021 in I. pacificus (99%, 99%, and 100% for ompA, 16S rRNA, and gltA, respectively), a bacterium that was previously identified in I. pacifiucs by PCR. Analysis of sequences from complete opening frames of five genes, 16S rRNA, gltA, ompA, ompB, and sca4, provided inference to the bacteria's classification among other Rickettsia species. The REIP isolate displayed 99.8%, 99.4%, 99.2%, 99.5%, and 99.6% nucleotide sequence identity for 16S rRNA, gltA, ompA, ompB, and sca4 gene, respectively, with genes of 'R. monacensis' str. IrR/Munich, indicating the REIP isolate is closely related to 'R. monacensis'. Our suggestion was further supported by phylogenetic analysis using concatenated sequences of 16S rRNA, gltA, ompA, ompB, and sca4 genes, concatenated sequences of dksA-xerC, mppA-purC, and rpmE-tRNAfMet intergenic spacer regions. Both phylogenetic trees implied that the REIP isolate is most closely related to 'R. monacensis' str. IrR/Munich. We propose the bacterium be considered as 'Rickettsia monacensis' str. Humboldt for its closest phylogenetic relative (=DSM 103975 T = ATCC TSD-94 T).


Asunto(s)
ADN Bacteriano/genética , Ixodes/microbiología , Ovario/microbiología , Rickettsia/clasificación , Rickettsia/aislamiento & purificación , Animales , Técnicas de Tipificación Bacteriana , California , ADN Intergénico , Femenino , Tipificación de Secuencias Multilocus , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
20.
Emerg Infect Dis ; 25(6): 1136-1143, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31107213

RESUMEN

Most tickborne disease studies in the United States are conducted in low-intensity residential development and forested areas, leaving much unknown about urban infection risks. To understand Lyme disease risk in New York, New York, USA, we conducted tick surveys in 24 parks throughout all 5 boroughs and assessed how park connectivity and landscape composition contribute to Ixodes scapularis tick nymphal densities and Borrelia burgdorferi infection. We used circuit theory models to determine how parks differentially maintain landscape connectivity for white-tailed deer, the reproductive host for I. scapularis ticks. We found forested parks with vegetated buffers and increased connectivity had higher nymph densities, and the degree of park connectivity strongly determined B. burgdorferi nymphal infection prevalence. Our study challenges the perspective that tickborne disease risk is restricted to suburban and natural settings and emphasizes the need to understand how green space design affects vector and host communities in areas of emerging urban tickborne disease.


Asunto(s)
Distribución Animal , Borrelia burgdorferi/aislamiento & purificación , Ixodes/microbiología , Enfermedad de Lyme/epidemiología , Parques Recreativos , Animales , Ecosistema , Humanos , Ixodes/fisiología , Enfermedad de Lyme/transmisión , Ciudad de Nueva York/epidemiología , Ninfa/microbiología , Ninfa/fisiología , Factores de Riesgo
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