First Detection of Borrelia burgdorferi sensu lato DNA in Serum of the Wild Boar (Sus scrofa) in Northern Portugal by Nested-PCR

The Role of Wild Boars in the Circulation of Tick-Borne Pathogens: The First Evidence of Rickettsia monacensis Presence

Most wild mammals can serve as hosts both for tick-borne pathogens (TBPs) and for the ticks themselves. Among these, wild boars, due to their large body size, habitat and life span, show high exposure to ticks and TBPs. These species are now one of the widest-ranging mammals in the world, as well as the most widespread suid. Despite the fact that certain local populations have been decimated by African swine fever (ASF), wild boars are still considered overabundant in most parts of the world, including Europe. Altogether, their long-life expectancy, large home ranges including migration, feeding and social behaviors, wide distribution, overabundance and increased chances of interactions with livestock or humans make them suitable sentinel species for general health threats, such as antimicrobial-resistant microorganisms, pollution and ASF geographical distribution, as well as for the distribution and abundance of hard ticks and also for certain TBPs, such as Anaplasma phagocytophilum. The aim of this study was to evaluate the presence of rickettsial agents in wild boars from two counties in Romania. Among 203 blood samples of wild boars (Sus scrofa ssp. attila) collected during 3 (2019-2022) hunting seasons (September-February), 15 were found positive for tick-borne pathogen DNA. Six wild boars were positive for A. phagocytophilum DNA presence and nine for Rickettsia spp. The identified rickettsial species were R. monacensis (six) and R. helvetica (three). No animal was positive either for Borrelia spp., Ehrlichia spp. or Babesia spp. To the best of our knowledge, this is the first report of R. monacensis in European wild boars, thus adding the third species from the SFG Rickettsia, in the epidemiology of which this wild species may have a role as a reservoir host.

Prevalence of selected tick-borne pathogens in wild ungulates and ticks in southern Spain

A survey study was carried out to assess the occurrence of selected tick-borne pathogens (TBP) in wild ungulates in Mediterranean ecosystems in southern Spain. Spleen samples were collected from 1,132 wild ungulates, including 578 red deer, 269 wild boar, 135 mouflon, 121 fallow deer and 29 roe deer, between 2009 and 2015. Eighty-nine ticks collected from TBP-positive animals were also analysed. Samples were tested by PCR and sequenced whenever possible. TBP DNA was detected in 127 of 863 wild ruminants (14.7%; 95% CI: 12.4-17.3) including the following: Anaplasma phagocytophilum (9.2%), Babesia divergens (2.9%), Theileria sp. OT3 (1.7%), Borrelia afzelii (0.7%) and Theileria capreoli (0.2%), but no positive samples were detected in wild boar (0/269). All the strains from mouflon were identified as Theileria sp. OT3, while B. divergens and T. capreoli were mainly found in red deer. Co-infection with A. phagocytophilum and B. divergens, and A. phagocytophilum and Theileria spp. was detected in red deer and mouflon, respectively. The risk factor analysis showed that the prevalences of A. phagocytophilum and piroplasms were species-related. Eighty-nine tick specimens collected from ungulates found to be infected with the selected TBP were identified as Hyalomma lusitanicum (95.5%) and Ixodes ricinus (4.5%). Thirty ticks were positive for Anaplasma/Ehrlichia spp. (33.7%), 25 for Babesia/Theileria (28.1%) and two for B. burgdorferi s.l. (2.3%). Eleven specimens showed co-infections with Anaplasma/Ehrlichia and Babesia/Theileria (10.1%) or Anaplasma/Ehrlichia and B. burgdorferi s.l. (2.3%). The estimated prevalences obtained in the present study suggest the possible contribution of wild ruminants to the maintenance of some selected TBP in Mediterranean ecosystems in southern Spain, while the role of wild boar in the epidemiology of these pathogens seems to be limited in this region.

Spotted fever group rickettsiae in Dermacentor marginatus from wild boars in Italy

Following the increase in wild boar population recorded in urban and peri-urban areas throughout Europe, the present survey aimed to assess the occurrence of zoonotic tick-borne pathogens (TBPs) in wild boars living in southern Italy and in their ticks for evaluating the potential risk of infection for animals and humans. From October to December 2019, a total of 176 ticks collected from 93 wild boars andtheir spleen samples were molecularly screened for selected TBPs. Overall, all the wild boars were infested by ticks (mean intensity, 1.9) with Dermacentor marginatus and Ixodes ricinus being identified in 99.4% and 0.6%, respectively. Out of 93 wild boars, 17 (18.3%) were infested by ticks which scored positive to spotted fever group (SFG) Rickettsia species. Rickettsia slovaca and Rickettsia raoultii were identified in 16 (9%) and 1 (0.6%) D. marginatus, respectively, whereas a single I. ricinus (0.6%) was infected by R. slovaca. A single wild boar (1.1%) tested positive to R. slovaca. All ticks and wild boars scored negative to Babesia/Theileria spp., Ehrlichia spp., Anaplasma spp., Candidatus Neoehrlichia spp., Coxiella burnetii and Borrelia burgdorferi sensu lato complex. Data herein obtained suggest that wild boars are involved in the maintenance of D. marginatus in the environment as in peri-urban areas herein investigated. An integrated management approach is advocated for wild boar population control and in preventing the potential risk of TBPs infection in animals and humans.

Molecular Identification of Borrelia afzelii from Ticks Parasitizing Domestic and Wild Animals in South Korea

Lyme borreliosis is one of the most prevalent tick-borne infectious zoonotic diseases caused by spirochetes of the Borrelia burgdorferi sensu lato group. The present study assessed the risk factors and prevalence of Lyme borreliosis in ticks parasitizing domestic and wild animals. A total of 589 ticks (329 tick pools) collected from animals were identified as Haemaphysalis longicornis, (85.7%), H. flava (10.0%), and Ixodes nipponensis (4.3%) using morphological and molecular methods in South Korea. In this study, the 5S–23S gene sequences of B. afzelii (6/329, 1.8%) were detected in ticks taken from mammals, including ticks from horses (2/147 pools, 1.4%), wild boar (1/19 pools, 5.3%), native Korean goats (NKG, 2/34 pools, 5.9%), and Korean water deer (1/129 pools, 0.8%). Unfortunately, ospA, pyrG, and flagellin genes were not able to be amplified in the present study. To our knowledge, our results are the first inclusive data available for B. afzelii circulation in several tick species taken from NKG, horses, and wild boar in South Korea. We believe that the current findings extend our knowledge of the distribution and possible vector spectrum of Borrelia spp. We recommend continuous evaluation of the potential public health threat posed by Borrelia infected ticks.

Infection in xenotransplantation: opportunities and challenges

PURPOSE OF REVIEW

Posttransplantation infections are common. It is anticipated that infection will be no less common in xenotransplantation recipients. Prolonged xenograft survivals have resulted from advances in immunosuppressive strategies and development of swine that decrease host immune responses via genetic manipulation, notably CRISPR/cas9 manipulation. As prospects for clinical trials improve, consideration of the unique infectious risks posed by xenotransplantation reemerge.

RECENT FINDINGS

Organisms likely to cause infection in human recipients of porcine xenografts are unknown in advance of clinical trials. Microbiological screening of swine intended as xenograft donors can be more intensive than is currently feasible for human allograft donors. Monitoring infection in recipients will also be more intensive. Key opportunities in infectious diseases of xenotransplantation include major technological advances in evaluation of the microbiome by unbiased metagenomic sequencing, assessments of some risks posed by porcine endogenous retroviruses (PERVs) including antiretroviral susceptibilities, availability of swine with deletion of genomic PERVs, and recognition of the rapidly changing epidemiology of infection in swine worldwide.

SUMMARY

Unknown infectious risks in xenotransplantation requires application of advanced microbiological techniques to discern and prevent infection in graft recipients. Clinical trials will provide an opportunity to advance the safety of all of organ transplantation.

Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia

BACKGROUND

Free-living ungulates are hosts of ixodid ticks and reservoirs of tick-borne microorganisms in central Europe and many regions around the world. Tissue samples and engorged ticks were obtained from roe deer, red deer, fallow deer, mouflon, and wild boar hunted in deciduous forests of south-western Slovakia. DNA isolated from these samples was screened for the presence of tick-borne microorganisms by PCR-based methods.

RESULTS

Ticks were found to infest all examined ungulate species. The principal infesting tick was Ixodes ricinus, identified on 90.4% of wildlife, and included all developmental stages. Larvae and nymphs of Haemaphysalis concinna were feeding on 9.6% of wildlife. Two specimens of Dermacentor reticulatus were also identified. Ungulates were positive for A. phagocytophilum and Theileria spp. Anaplasma phagocytophilum was found to infect 96.1% of cervids, 88.9% of mouflon, and 28.2% of wild boar, whereas Theileria spp. was detected only in cervids (94.6%). Importantly, a high rate of cervids (89%) showed mixed infections with both these microorganisms. In addition to A. phagocytophilum and Theileria spp., Rickettsia helvetica, R. monacensis, unidentified Rickettsia sp., Coxiella burnetii, "Candidatus Neoehrlichia mikurensis", Borrelia burgdorferi (s.l.) and Babesia venatorum were identified in engorged I. ricinus. Furthermore, A. phagocytophilum, Babesia spp. and Theileria spp. were detected in engorged H. concinna. Analysis of 16S rRNA and groEL gene sequences revealed the presence of five and two A. phagocytophilum variants, respectively, among which sequences identified in wild boar showed identity to the sequence of the causative agent of human granulocytic anaplasmosis (HGA). Phylogenetic analysis of Theileria 18S rRNA gene sequences amplified from cervids and engorged I. ricinus ticks segregated jointly with sequences of T. capreoli isolates into a moderately supported monophyletic clade.

CONCLUSIONS

The findings indicate that free-living ungulates are reservoirs for A. phagocytophilum and Theileria spp. and engorged ixodid ticks attached to ungulates are good sentinels for the presence of agents of public and veterinary concern. Further analyses of the A. phagocytophilum genetic variants and Theileria species and their associations with vector ticks and free-living ungulates are required.

Broad-range survey of vector-borne pathogens and tick host identification of Ixodes ricinus from Southern Czech Republic

Ixodes ricinus ticks are vectors of numerous human and animal pathogens. They are host generalists able to feed on more than 300 vertebrate species. The prevalence of tick-borne pathogens is influenced by host-vector-pathogen interactions that results in spatial distribution of infection risk. Broad-range polymerase chain reaction electrospray ionization mass spectrometry (PCR/ESI-MS) was used to analyze 435 I. ricinus nymphs from four localities in the south of the Czech Republic for the species identification of tick-borne pathogens. Borrelia burgdorferi sensu lato spirochetes were the most common pathogen detected in the ticks; 21% of ticks were positive for a single genospecies and 2% were co-infected with two genospecies. Other tick-borne pathogens detected included Rickettsia helvetica (3.9%), R. monacensis (0.2%), Anaplasma phagocytophilum (2.8%), Babesia venatorum (0.9%), and Ba. microti (0.5%). The vertebrate host of the ticks was determined using PCR followed by reverse line blot hybridization from the tick's blood-meal remnants. The host was identified for 61% of ticks. DNA of two hosts was detected in 16% of samples with successful host identification. The majority of ticks had fed on artiodactyls (50.7%) followed by rodents (28.6%) and birds (7.8%). Other host species were wild boar, deer, squirrels, field mice and voles.

Tick-borne bacteria and protozoa detected in ticks collected from domestic animals and wildlife in central and southern Portugal

Ticks are vectors of many human and animal pathogens. The aim of this study was to screen bacteria and protozoa from ticks infesting domestic animals and wildlife collected in central and southern Portugal. A total of 593 ticks, comprising 465 (78.4%) adults, 122 (20.6%) nymphs, and six (1.0%) larvae, were collected from 283 hosts of 25 different species (4 domestic and 21 wild). Overall, the analysis of DNA extracts prepared from ticks collected from hosts of 11 different species in the districts of Castelo Branco, Portalegre, Lisboa, Setúbal, Beja and Faro, revealed the presence of genomic sequences from Anaplasma sp., A. ovis, Babesia sp., relapsing fever-like Borrelia sp., Ehrlichia spp., Rickettsia aeschlimannii, Ri. helvetica, Ri. massiliae, Ri. raoultii, Ri. slovaca, Candidatus Ri. barbariae, Theileria annulata and T. ovis, in specimens of Dermacentor marginatus, Hyalomma lusitanicum, Hy. marginatum, Rhipicephalus bursa and Rh. sanguineus sensu lato. The obtained results suggest the circulation of a wide variety of infectious agents, some of zoonotic concern, in hard ticks from Portugal. Further studies should be conducted to better characterize (both genetically and phenotypically) the putative novel microorganisms detected, both in what regards their potential pathogenity towards vertebrates, and to assist the implementation of effective control strategies for the management of ticks and human and animal tick-borne pathogens.

The domestic pig as a potential model for Borrelia skin infection

The skin lesion erythema migrans is a characteristic early manifestation of Lyme borreliosis in humans. However, the pathomechanisms leading to development of this erythema are not fully understood. Models that mimic human skin would enhance research in this field. Human and porcine skin structures strongly resemble each other. Therefore, we attempted to induce erythema migrans lesions in experimental Borrelia burgdorferi sensu lato infection in the skin of domestic pigs. The formation of erythema migrans-like lesions was observed after intradermal injection of these spirochetes, with the lesions forming very clearly in 2/6 animals when a strain of B. garinii was used. However, no molecular or clinical proof of systemic infection of the pigs with B. afzelii, B. burgdorferi sensu stricto, or B. garinii could be achieved.

Molecular detection of tick-borne bacteria and protozoa in cervids and wild boars from Portugal

Background

Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal.

Methods

One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR.

Results

Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp.

Conclusions

This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of  Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken.