Phylogenetic Studies of Coxiella-Like Bacteria and Spotted Fever Group Rickettsiae in Ticks Collected From Vegetation in Chaiyaphum Province, Thailand

Molecular prevalence of Coxiella like endosymbionts and the first record of Coxiella burnetii in hard ticks from Southern Thailand

Eight hard tick species were identified among a total of 466 samples collected from vegetation in southern Thailand: Dermacentor compactus (n = 150), D. steini (n = 100), D. auratus (n = 85), D. tricuspis (n = 41), Haemaphysalis hystricis (n = 69), H. semermis (n = 3), H. shimoga (n = 2) and Amblyomma testudinarium (n = 16). In 93 ticks from these 8 species, Coxiella bacteria were detected via 16 S rRNA, groEL (60-kDa chaperone heat shock protein B) and rpoB (β subunit of bacterial RNA polymerase) genes. Interestingly, Coxiella burnetii was detected for the first time in H. hystricis and D. steini in Songkhla Province. Coxiella-like endosymbionts (CLEs) were also found in 84 ticks from 7 species, namely, D. compactus, D. auratus, D. tricuspis, H. hystricis, H. semermis, H. shimoga and A. testudinarium. Among these, CLEs associated with D. compactus and H. semermis were reported for the first time in Thailand. Phylogenetic analysis and generation of a haplotype network clearly revealed 2 distinct groups of Coxiella bacteria, namely, C. burnetii and CLEs. The nucleotide alignment of Coxiella 16 S rRNA revealed differences in bases at 3 positions between C. burnetii and CLEs. Thus, these differences could be used as liable molecular markers for discriminating these 2 groups in hard ticks.

Francisella tularensis in Wild Lagomorphs in Southern Spain's Mediterranean Ecosystems

Francisella tularensis is a vector-borne zoonotic bacterium that causes tularemia, a disease of great importance for animal and public health. Although wild lagomorphs are considered one of the major reservoirs of this bacterium, information about the circulation of F. tularensis in European wild rabbit (Oryctolagus cuniculus) and Iberian hare (Lepus granatensis) populations in Europe is still very limited. In Spain, F. tularensis is present in northern central regions, with recurrent outbreaks occurring annually. However, southern Spain has been neglected in terms of monitoring and research. Thus, the aim of this study was to investigate the occurrence of F. tularensis in wild lagomorphs in the Mediterranean ecosystems of southern Spain through using molecular techniques. Spleen samples from 774 European wild rabbits and 178 Iberian hares were collected on 135 hunting grounds between the 2017/2018 and 2022/2023 hunting seasons. A primer set targeting the 16S rRNA gene was used for the detection of F. tularensis DNA. None of the 952 (0.0%; 95%CI: 0.0-0.4) wild lagomorphs sampled showed presence of F. tularensis DNA. Our finding indicates the absence or very low circulation of the bacterium in wild rabbit and Iberian hare populations in the Mediterranean ecosystems of southern Spain, denoting a limited risk of transmission of this pathogen from wild lagomorphs to other sympatric species, including human beings, in this Iberian region.

Diversity of questing ticks and prevalence of tick-associated pathogens in Khao Kheow-Khao Chomphu Wildlife Sanctuary, Chon Buri, Thailand

Ixodid ticks are important vectors for tick-borne diseases distributed worldwide, including Thailand. Recreation areas within wildlife habitats are considered high-risk zones for tick exposure and tick-borne disease in humans. The study aimed to determine seasonal variations in tick diversity and pathogen prevalence in Khao Kheow-Khao Chomphu Wildlife Sanctuary, Chon Buri, Thailand. From November 2021 to March 2023, a total of 1331 immature ticks were collected by dragging. The proportion of collected larvae was highest in February 2022, while the number of collected nymphs peaked in December 2021. Seven tick species were molecularly identified: Haemaphysalis lagrangei, H. wellingtoni, H. shimoga, H. obesa, Dermacentor auratus, Rhipicephalus microplus, and Amblyomma integrum. Of 80 tick pools, Anaplasma, piroplasms (Babesia and Theileria), Bartonella, and Rickettsia were detected in 10% (8/80), 3.75% (3/80), 1.25% (1/80), and 3.75% (3/80) of tick pools, respectively. Phylogenetic analysis grouped the newly generated sequences in the clades of Anaplasma bovis, Babesia gibsoni, Theileria cervi, Bartonella henselae, and Rickettsia montanensis. A seasonal pattern of pathogen appearance was detected during November to February, the cool season in Thailand. Based on our results indicating the highest peak of immature ticks and prevalence of pathogens, visitors should take precautions to avoid tick exposure during this season.

Haemaphysalis wellingtoni (Acari: Ixodidae) from the helmeted guineafowl, Numida meleagris (Galliformes: Numididae): A new tick-host record in Peninsular Malaysia

This paper describes a new tick-host record of Haemaphysalis wellingtoni from the helmeted guineafowl (Numida meleagris) in Peninsular Malaysia. This record is also the first report of a tick infestation from N. meleagris in Asia. A checklist of the tick-guineafowl associations has been designed, resulting in 32 tick species including H. wellingtoni recorded as infesting N. meleagris worldwide. A list of pathogens harboured or transmitted by H. wellingtoni is provided. The status of H. wellingtoni as a true parasite of N. meleagris, and the health threat posed to the guineafowls are discussed in this paper.