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19 pages, 15583 KB

Open AccessArticle

Distribution and Genetic Diversity of Borrelia from Lyme Borreliosis and Relapsing Fever Groups in Ixodidae Ticks in the Russian Far East

by Yuliya Sabitova, Vera Rar, Valeria Fedorets, Yana Igolkina, Tamara Epikhina, Aleksey Nikitin, Yulia Verzhutskaya, Valentina Kolesnikova, Natalia Gordeiko, Natalya Pukhovskaya and Nina Tikunova

Pathogens 2026, 15(7), 775; https://doi.org/10.3390/pathogens15070775 - 22 Jul 2026

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Abstract

Ixodidae ticks are vectors of pathogenic spirochetes from the Borrelia burgdorferi sensu lato (s.l.) complex and the relapsing fever (RF) group. The Russian Far East is endemic for borrelioses, yet data on the distribution and genetic diversity of Borrelia spp. in this region [...] Read more.

Ixodidae ticks are vectors of pathogenic spirochetes from the Borrelia burgdorferi sensu lato (s.l.) complex and the relapsing fever (RF) group. The Russian Far East is endemic for borrelioses, yet data on the distribution and genetic diversity of Borrelia spp. in this region remain scarce. We examined 3107 Ixodidae ticks (Ixodes spp., Haemaphysalis spp., and Dermacentor silvarum), collected from two mainland provinces and five islands of the Russian Far East in 2005–2023. A total of 86 Borrelia afzelii, 297 Borrelia bavariensis, 81 Borrelia garinii, 44 Borrelia miyamotoi, and 33 unclassified RF borreliae were identified. Borrelia burgdorferi s.l. and B. miyamotoi were strongly associated with Ixodes spp., whereas unclassified RF borreliae were associated with Haemaphysalis spp. Among B. burgdorferi s.l. isolates, B. afzelii and B. bavariensis were found significantly more frequently in I. persulcatus compared to I. pavlovskyi, whereas B. garinii was significantly more common in I. pavlovskyi. Genetic characterization of B. burgdorferi s.l. revealed high haplotypic diversity, particularly within B. bavariensis and B. garinii. Among RF borreliae, all B. miyamotoi isolates were highly conserved and belonged to the Asian type. In contrast, unclassified RF borreliae were genetically variable and clustered with RF borreliae previously found in Haemaphysalis and Rhipicephalus ticks. The obtained results expand the understanding of the distribution and genetic diversity of Borrelia spp. in the Russian Far East. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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14 pages, 9647 KB

Open AccessArticle

Underrecognized Tick-Borne Encephalitis in Serbia: Evidence from Patients with Suspected West Nile Virus Neuroinvasive Disease

by Dragana Mijatović, Ana Marija Radevska, Dejan Jakimovski, Lidija Popović-Dragonjić, Biljana Popovska Jovičić, Jagoda Gavrilović, Siniša Sević, Dajana Lendak, Irina Stojanac, Alejandro Cabezas-Cruz, Andreas Pilz, Tomás Cervantes Rincón, Jasmine Oberti-Cantergiani, Davide F. Robbiani and Pavle Banović

Pathogens 2026, 15(6), 587; https://doi.org/10.3390/pathogens15060587 - 29 May 2026

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Abstract

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe, but its epidemiology remains poorly defined in Serbia. In orthoflavivirus-endemic settings, diagnostic challenges may contribute to underrecognition of TBE, particularly among patients with suspected West Nile virus (WNV) infection. We conducted a multicenter [...] Read more.

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe, but its epidemiology remains poorly defined in Serbia. In orthoflavivirus-endemic settings, diagnostic challenges may contribute to underrecognition of TBE, particularly among patients with suspected West Nile virus (WNV) infection. We conducted a multicenter retrospective study including patients hospitalized between 2018 and 2023 with suspected WNV neuroinvasive disease or viral encephalitis of unknown etiology. Serum samples were tested for TBEV-neutralizing antibodies using a microneutralization assay. Among 79 patients, TBEV-neutralizing antibodies were detected in four (5.1%). Most reactive cases occurred in patients initially classified as having suspected WNV-associated meningoencephalitis, while TBE had not been considered in the differential diagnosis at admission. These findings suggest that TBE may be underrecognized in Serbia and highlight the importance of confirmatory testing in orthoflavivirus-endemic settings. Strengthening clinical awareness and surveillance will be essential to better define the burden of TBE and inform prevention strategies. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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18 pages, 1042 KB

Open AccessCommunication

Interlaboratory Concordance of a Multiplex ELISA for Lyme and Lyme-like Illness Using Australian Samples and Commercial Reference Panels: A Proof-of-Concept Study

by Kunal Garg, Fausto Villavicencio-Aguilar, Flora Solano-Rivera and Leona Gilbert

Pathogens 2025, 14(12), 1281; https://doi.org/10.3390/pathogens14121281 - 12 Dec 2025

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Abstract

Tick bites acquired in the northern or southern hemisphere can transmit microbes that may cause illness. The most prevalent infection is Lyme borreliosis (LB), with all proven cases to date having been acquired in the northern hemisphere. The existence of endemic LB in [...] Read more.

Tick bites acquired in the northern or southern hemisphere can transmit microbes that may cause illness. The most prevalent infection is Lyme borreliosis (LB), with all proven cases to date having been acquired in the northern hemisphere. The existence of endemic LB in Australia has not been proven explicitly, and there is uncertainty concerning the cause of “Lyme-like” disease (LLD) in Australia. As many tick-borne diseases (TBDs) are diagnosed by serology, validated assays for use in both the northern and southern hemispheres are required. Using a multiplex enzyme-linked immunosorbent assay (TICKPLEX^®), two independent laboratories tested a total of 53 well-characterized reference sera that consisted of 33 samples from northern hemisphere patients with confirmed tick-borne disease (TBD) and 20 randomly selected sera from Australian patients with suspected TBDs, presenting with or without LLD. Antibody responses to multiple microbial antigens from causative agents of TBDs were found. High concordance between laboratories was demonstrated on this small set of samples. The results obtained provide the basis for further evaluation of TICKPLEX^® on a larger number of samples from Australian patients with suspected TBDs. These findings should be considered preliminary, providing proof-of-concept evidence that warrants validation in larger, clinically diverse cohorts. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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18 pages, 2348 KB

Open AccessArticle

Metagenomic Profile of Bacterial Communities of Hyalomma scupense and Hyalomma asiaticum Ticks in Kazakhstan

by Kulyaisan T. Sultankulova, Nurlan S. Kozhabergenov, Gaukhar O. Shynybekova, Meirim D. Almezhanova, Samat B. Zhaksylyk, Madina R. Abayeva, Olga V. Chervyakova, Takhmina O. Argimbayeva and Mukhit B. Orynbayev

Pathogens 2025, 14(10), 1008; https://doi.org/10.3390/pathogens14101008 - 6 Oct 2025

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Abstract

Ticks are important vectors of pathogens affecting humans and animals, posing a serious threat to health. For the first time, we studied the metagenomic profile of the microbial composition of Hyalomma scupense and Hyalomma asiaticum ticks in Kazakhstan. A total of 94 adult [...] Read more.

Ticks are important vectors of pathogens affecting humans and animals, posing a serious threat to health. For the first time, we studied the metagenomic profile of the microbial composition of Hyalomma scupense and Hyalomma asiaticum ticks in Kazakhstan. A total of 94 adult H. asiaticum and H. scupense ticks collected from randomly selected cattle in Kazakhstan in 2023 were analyzed. 16S rRNA gene sequencing was performed using the Ion Torrent NGS platform. Taxonomic classification was carried out in the BV-BRC platform with the Kraken2 database. Metagenomic analysis revealed 26 bacterial genera, including both pathogenic and symbiotic taxa. In H. scupense, the dominant groups were Francisella (89.0%), Staphylococcus (76.0%) and Candidatus Midichloria (61.0%), while in H. asiaticum, they were Francisella (99.0% and 95.0%) and Helcococcus (65.0%). In male H. scupense, the proportion of Francisella reached 89%, whereas in females, it varied from 2% to 28%. In H. asiaticum, Helcococcus accounted for 65% in males compared to 11% in females. This is the first report on the metagenomic profile of the microbiota of H. scupense and H. asiaticum in Kazakhstan. The detection of pathogens indicates a risk of their transmission to humans and animals and highlights the need to develop new tick control strategies. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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14 pages, 290 KB

Open AccessArticle

Tick Species Identification and Zoonotic Bacteria Detection from Healthcare-Extracted Specimens from Humans in the Basque Country, Northern Iberian Peninsula

by Patirke Ibarrondo-Mendiola, Patricia Vázquez, Miriam Alkorta, Cristina Zugazaga, Ana L. García-Pérez, Jesús F. Barandika and Aitor Cevidanes

Pathogens 2025, 14(6), 561; https://doi.org/10.3390/pathogens14060561 - 4 Jun 2025

Cited by 2 | Viewed by 1885

Abstract

Hard ticks are vectors of a wide range of pathogens, with tick-borne bacteria being among the most frequently detected. This study presents a first approach to the identification of human-biting ticks in the Basque Country (northern Iberian Peninsula), where previous research has mainly [...] Read more.

Hard ticks are vectors of a wide range of pathogens, with tick-borne bacteria being among the most frequently detected. This study presents a first approach to the identification of human-biting ticks in the Basque Country (northern Iberian Peninsula), where previous research has mainly focused on ticks from vegetation and domestic and wild animals. The aim of this study was (i) to identify tick species collected in hospitals and health centres and (ii) to determine the presence and identify of pathogenic bacteria that they may carry using PCR, RLB and sequencing methods. A total of 181 ticks were collected and grouped in pools of one, two or three specimens, resulting in 157 samples. Morphological and molecular identification of collected ticks revealed that most specimens belonged to Ixodes ricinus (88.5%). Additionally, Rhipicephalus bursa, Haemaphysalis punctata, Dermacentor reticulatus and Dermacentor marginatus were also identified. A total of 25 samples (15.9%) tested positive for DNA from the targeted pathogens. The most prevalent vector-borne bacteria were Borrelia spp. (6.4%), followed by Rickettsia spp. (5.1%), Anaplasma phagocytophilum (2.5%) and Coxiella spp. (1.9%). Species identified included B. afzelii, B. garinii, B. miyamotoi, B. valaisiana, B. burgdorferi s. s., R. monacensis, “Candidatus R. rioja”, R. helvetica and R. massiliae. This study highlights the usefulness of combining molecular diagnostics with passive surveillance of human-attached ticks as an effective tool for regional monitoring of ticks and tick-borne pathogens. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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7 pages, 520 KB

Open AccessCommunication

The First Molecular Detection of Theileria luwenshuni from Haemaphysalis mageshimaensis on Orchid Island, Taiwan, with No Evidence of SFTSV

by Pai-Shan Chiang, I-Jung Tsai, Yuan-Wei Hu, Hung-Jui Chen, I-Jen Chen, Hwa-Jen Teng and Shiu-Ling Chen

Pathogens 2025, 14(3), 241; https://doi.org/10.3390/pathogens14030241 - 3 Mar 2025

Cited by 1 | Viewed by 2829

Abstract

Theileriosis is considered an economically important disease that may decrease productivity and cause a high mortality rate in livestock. Only a few studies have reported Theileria spp., such as T. sergenti and T. buffeli, in recent decades in Taiwan. In the present [...] Read more.

Theileriosis is considered an economically important disease that may decrease productivity and cause a high mortality rate in livestock. Only a few studies have reported Theileria spp., such as T. sergenti and T. buffeli, in recent decades in Taiwan. In the present study, 401 ticks have been collected on Orchid Island in June 2022 and April 2023. Our environmental investigation for SFTSV unintentionally discovered T. luwenshuni in Haemaphysalis mageshimaensis on Orchid Island via PCR. The PCR products were sequenced, and the detected 18S rRNA gene sequences shared a 99.65–99.93% identity with T. luwenshuni sequences from ticks and ruminants in Myanmar and China. Despite the difficulty in clarifying the source of T. luwenshuni within neighboring regions, our findings provide an updated distribution of T. luwenshuni in Asia. This is not only the first time that T. luwenshuni was found in H. mageshimaensis but also the first report of T. luwenshuni on Orchid Island, Taiwan. Our study indicates that ruminants may be at risk of infection. Therefore, further investigations are needed to determine the distribution of T. luwenshuni among ruminants on Orchid Island and in Taiwan. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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27 pages, 2775 KB

Open AccessSystematic Review

Six Decades of Global Research on Bovine Babesiosis Vaccines: A Comprehensive Systematic Review and Meta-Analysis

by Uriel Mauricio Valdez-Espinoza, Chyntia Pérez-Almeida, Alma Cárdenas-Flores, Edwin Esaú Hernández-Arvizu and Juan Mosqueda

Pathogens 2026, 15(5), 500; https://doi.org/10.3390/pathogens15050500 - 6 May 2026

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Abstract

Bovine babesiosis is a tick-borne disease that poses significant economic losses to global cattle production, and diverse vaccine platforms have been developed to combat it. This work critically evaluates global research on bovine babesiosis vaccines, integrating historical milestones with recent advances in antigen [...] Read more.

Bovine babesiosis is a tick-borne disease that poses significant economic losses to global cattle production, and diverse vaccine platforms have been developed to combat it. This work critically evaluates global research on bovine babesiosis vaccines, integrating historical milestones with recent advances in antigen discovery and immunization approaches and assessing their protective efficacy through meta-analysis. Using comprehensive database searches, we identified 413 publications on bovine babesiosis vaccines, of which 168 met the inclusion criteria, spanning from 1960 to August 2025. Analysis revealed that B. bovis dominated the research output, followed by B. bigemina and B. divergens. Five key methodological approaches emerged: field trials, controlled experiments, immunogenicity assessments, in vitro assays, and in silico antigen analyses, with a notable shift toward immunogenicity and computational studies post-2000. Frequently studied antigens included RAP-1, MSA-2c, AMA-1, 11C5, and 12D3 (B. bovis); RAP-1 and GP45 (B. bigemina); and Bd37 (B. divergens). Geographically, research was concentrated in the United States, Australia, Argentina, Mexico, and France, which were identified as the top contributors in that order, primarily focusing on live and recombinant vaccines, with minimal African participation despite high cattle populations. Bibliometric analysis showed increasing publication output, with leading journals such as Veterinary Parasitology, Infection and Immunity, and Parasites & Vectors as the top three. Thematic evolution highlighted a transition from live vaccines to recombinant and multi-epitope strategies, with increasing emphasis on conserved antigens and novel platforms. However, more field evaluations are required to determine whether these new technologies can achieve protective efficacy comparable to that of live vaccines. This work underscores the need for sustained investment, intersectoral collaboration, and validation using standardized and comparable metrics in field trials to translate laboratory innovations into effective, safe, and globally accessible vaccines against bovine babesiosis. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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10 pages, 1378 KB

Open AccessBrief Report

The Occurrence of Borrelia burgdorferi sensu lato in Ixodes ricinus Ticks Collected from Nature-Educational and Tourist Trails in the Poprad Landscape Park

by Sylwia Koczanowicz, Magdalena Nowak-Chmura, Anna Kocoń, Grzegorz Rączka and Marek Asman

Pathogens 2025, 14(2), 117; https://doi.org/10.3390/pathogens14020117 - 26 Jan 2025

Cited by 1 | Viewed by 3632

Abstract

Throughout Europe, including Poland, Ixodes ricinus ticks are the main vector of numerous pathogenic agents that pose a serious threat to public health. Southern Poland attracts many tourists with its scenic landscapes and abundant recreational opportunities. These areas are ideal habitats for wild [...] Read more.

Throughout Europe, including Poland, Ixodes ricinus ticks are the main vector of numerous pathogenic agents that pose a serious threat to public health. Southern Poland attracts many tourists with its scenic landscapes and abundant recreational opportunities. These areas are ideal habitats for wild fauna, which serve as the main reservoirs and hosts for these pathogens and ticks. The large population and biodiversity of these hosts facilitate the proliferation of ticks. The aim of this study was to determine the potential exposure of humans to ticks and tick-borne pathogens such as Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Babesia spp., along the nature-educational and tourist trails of the Poprad Landscape Park. From 2020 to 2021, ticks were collected using the flagging method on three tourist trails and nature-educational paths within the Poprad Landscape Park. DNA was isolated from 213 I. ricinus ticks using the ammonia method. To detect pathogens in ticks, PCR and nested PCR methods were used. To detect B. burgdorferi s.l. and A. phagocytophilum, two pairs of primers specific to the flaB gene fragment and 16S rRNA gene fragment were used, respectively. For Babesia spp. detection, primers specific to the 18S rRNA gene were used. The amplification products were separated electrophoretically and visualized under ultraviolet light. In total, among the 213 examined ticks, B. burgdorferi s.l. was detected in 31% of the samples. Neither A. phagocytophilum nor Babesia spp. were detected in the studied material. These results indicate a potentially high risk of ticks and tick-borne B. burgdorferi s.l. infections for residents and tourists in the recreational areas of the Poprad Landscape Park. Full article

(This article belongs to the Special Issue Ticks and Tick-Borne Pathogens in a Changing World)

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