First Report of Rickettsia conorii in Hyalomma kumari Ticks

Molecular detection of Anaplasma bovis, Candidatus Anaplasma boleense and Rickettsia spp. in ticks infesting small ruminants

Anaplasma spp. and Rickettsia spp. are intracellular vector-borne pathogens and harbored by a wide range of ticks and vertebrate hosts. Aim of this study was to molecularly characterize Anaplasma spp. and Rickettsia spp. in different ticks collected from livestock hosts in nine districts of Khyber Pakhtunkhwa (KP), Pakistan. In total, 862 ticks were collected from cattle, goats and sheep. Highest tick's infestation was observed on cattle 56.14% (32/57), followed by goats 45.45% (40/88), and sheep 42.05% (45/107). Rhipicephalus microplus (305/862, 35.38%) was predominant species, followed by Haemaphysalis sulcata (243/862, 28.19%), Hyalomma anatolicum (133/862, 15.42%), Haemaphysalis bispinosa (120/862, 13.92%), and Hyalomma kumari (61/862, 7.07%). A subset of 135 ticks were screened for Anaplasma spp. and Rickettsia spp. based on the amplification of partial 16 S rDNA and outer-membrane protein A (ompA) fragments, respectively. In total, 16 ticks (11.85%) were positive for Anaplasma spp. and Rickettsia spp. Obtained 16 S rDNA sequences for Anaplasma spp. detected in Ha. bispinosa and Ha. sulcata showed 99.98% identity with Anaplasma bovis, while other detected in Rh. microplus showed 99.84% identity with Candidatus Anaplasma boleense. Similarly, detected ompA sequence in Ha. sulcata showed 100% identity with Rickettsia sp. and 97.93% with Rickettsia slovaca, and another sequence detected in Rh. microplus showed 100% identity with Candidatus Rickettsia shennongii. In phylogenetic trees, these sequences clustered with corresponding species from Pakistan, China, Turkey, South Korea, South Africa, and Herzegovina. This is the first study reporting detection of A. bovis in Ha. bispinosa and Ha. sulcata, Ca. A. boleense in Rh. microplus collected from goats, and R. slovaca-like in Ha. sulcata. Our results enforce the need for regular surveillance of Rickettsiales in hard ticks infesting livestock in the region.

First record of Alectorobius coniceps (Ixodoidea: Argasidae) and Dermacentor sp. (Ixodoidea: Ixodidae) in Pakistan

Alectorobius species are soft ticks primarily infesting birds, such as swallows, while Dermacentor species are hard ticks mainly infesting mammals, such as small ruminants. This study for the first time reported on the morphological and molecular bases of two tick species, namely A. coniceps and a Dermacentor sp. in Pakistan. The former species was examined in swallows' nests in Khyber Pakhtunkhwa province, while the latter species was examined in small ruminants in Balochistan province. In total, 25 ticks were collected, with 14 ticks morphologically identified as A. coniceps (males = 9 and females = 5) and 11 ticks identified as Dermacentor sp. (males = 7 and females = 4). Following morphological identification, molecular identification was gained by obtaining 16S rDNA and cox1 sequences for these ticks. The BLAST results for the 16S rDNA and cox1 sequences from A. coniceps shared a maximum identity of 97.46% and 96.49% with the same species from Malta. The BLAST analysis of the 16S rDNA and cox1 sequences from Dermacentor sp. showed maximum identities of 98.42% and 97.45% with Dermacentor pavlovskyi from China. The phylogenetic analysis based on 16S rDNA and cox1 of A. coniceps showed a close evolutionary relationship with the same species. The case of Dermacentor sp., based on 16S DNA and cox1, indicated a close evolutionary relationship with Dermacentor pavlovskyi from China.

First report of spotted fever group Rickettsia aeschlimannii in Hyalomma turanicum, Haemaphysalis bispinosa, and Haemaphysalis montgomeryi infesting domestic animals: updates on the epidemiology of tick-borne Rickettsia aeschlimannii

Tick-borne Rickettsia spp. have long been known as causative agents for zoonotic diseases. We have previously characterized Rickettsia spp. in different ticks infesting a broad range of hosts in Pakistan; however, knowledge regarding Rickettsia aeschlimannii in Haemaphysalis and Hyalomma ticks is missing. This study aimed to obtain a better understanding about R. aeschlimannii in Pakistan and update the knowledge about its worldwide epidemiology. Among 369 examined domestic animals, 247 (66%) were infested by 872 ticks. Collected ticks were morphologically delineated into three genera, namely, Rhipicephalus, Hyalomma, and Haemaphysalis. Adult females were the most prevalent (number ₌ 376, 43.1%), followed by nymphs (303, 34.74%) and males (193, 22.13%). Overall, genomic DNA samples of 223 tick were isolated and screened for Rickettsia spp. by the amplification of rickettsial gltA, ompA, and ompB partial genes using conventional PCR. Rickettsial DNA was detected in 8 of 223 (3.58%) ticks including nymphs (5 of 122, 4.0%) and adult females (3 of 86, 3.48%). The rickettsial gltA, ompA, and ompB sequences were detected in Hyalomma turanicum (2 nymphs and 1 adult female), Haemaphysalis bispinosa (1 nymph and 1 adult female), and Haemaphysalis montgomeryi (2 nymphs and 1 adult female). These rickettsial sequences showed 99.71-100% identity with R. aeschlimannii and phylogenetically clustered with the same species. None of the tested Rhipicephalus microplus, Hyalomma isaaci, Hyalomma scupense, Rhipicephalus turanicus, Hyalomma anatolicum, Rhipicephalus haemaphysaloides, Rhipicephalus sanguineus, Haemaphysalis cornupunctata, and Haemaphysalis sulcata ticks were found positive for rickettsial DNA. Comprehensive surveillance studies should be adopted to update the knowledge regarding tick-borne zoonotic Rickettsia species, evaluate their risks to humans and livestock, and investigate the unexamined cases of illness after tick bite among livestock holders in the country.

Molecular evidence of Borrelia theileri and closely related Borrelia spp. in hard ticks infesting domestic animals

Ticks pose significant threats to hosts by transmitting Borrelia spp., which are grouped into Lyme borreliae, relapsing fever borreliae (RF), and reptiles- and monotremes-associated borreliae. The RF borreliae encompass a group of Borrelia species predominantly transmitted by soft ticks, but some of its members can also be transmitted by hard ticks. Information on the detection and genetic characterization of tick-borne RF borreliae, including Borrelia theileri, is notably rare in Asia, particularly in Pakistan. Herein, we employed molecular techniques to detect borreliae in hard ticks collected from domestic animals in Khyber Pakhtunkhwa, Pakistan. Ticks were subjected to morphological analysis, followed by DNA extraction and PCR amplification of partial fragments of borrelial 16S rRNA and flaB genes. A total of 729 ticks were collected from 264 hosts, with Haemaphysalis cornupunctata (12.9%; 94/729) being the most prevalent, followed by Hyalomma anatolicum (11.7%; 85/729), Rhipicephalus microplus (10.0%; 73/729), Haemaphysalis kashmirensis (9.1%; 66/729), Haemaphysalis bispinosa (8.5%; 62/729), Rhipicephalus sanguineus (8%; 58/729), Haemaphysalis montgomeryi (6.2%; 45/729), Rhipicephalus turanicus (5.5%; 40/729), Hyalomma dromedarii and Ixodes kashmirensis (4.4%; 32/729 each), Rhipicephalus haemaphysaloides (4.1%; 30/729), Haemaphysalis sulcata and Hyalomma scupense (3.8%; 28/729 each), Haemaphysalis danieli (2.9%; 21/729), Hyalomma kumari (2.6%; 19/729), and Hyalomma isaaci (2.2%; 16/729). Based on 16S rRNA detection of Borrelia spp., only R. turanicus yielded positive results, resulting in an overall infection rate of 0.3% (2/160), while using flaB-based detection, four tick species including R. microplus, R. turanicus, Ha. sulcata, and Ha. cornupunctata showed positive results, yielding an overall infection rate of 6.9% (11/160). The amplified DNA fragments of borrelial 16S rRNA and flaB in R. turanicus from goats shared maximum identities of 100 and 99.40% with Borrelia theileri, respectively. Amplified borrelial flaB fragments in R. microplus from cows and sheep displayed 100% identity with B. theileri, while flaB fragments in Ha. cornupunctata and Ha. sulcata from goats revealed identities of 99.32 and 99.75% with undetermined RF Borrelia spp., respectively. Phylogenetic analysis revealed clustering of B. theileri from R. microplus and R. turanicus with the same species, while Borrelia spp. from Ha. cornupunctata and Ha. sulcata with undetermined RF Borrelia spp. Notably, this research marks the first documentation of B. theileri in R. turanicus and the identification of RF Borrelia spp. in Ha. cornupunctata and Ha. sulcata.

Molecular Detection of Rickettsia hoogstraalii in Hyalomma anatolicum and Haemaphysalis sulcata: Updated Knowledge on the Epidemiology of Tick-Borne Rickettsia hoogstraalii

Ticks are hematophagous ectoparasites that transmit pathogens to animals and humans. Updated knowledge regarding the global epidemiology of tick-borne Rickettsia hoogstraalii is dispersed, and its molecular detection and genetic characterization are missing in Pakistan. The current study objectives were to molecularly detect and genetically characterize Rickettsia species, especially R. hoogstraalii, in hard ticks infesting livestock in Pakistan, and to provide updated knowledge regarding their global epidemiology. Ticks were collected from livestock, including goats, sheep, and cattle, in six districts of Khyber Pakhtunkhwa (KP) Pakistan. Overall, 183 hosts were examined, of which 134 (73.2%), including goats (number = 39/54, 72.2%), sheep (23/40, 57.5%), and cattle (71/89, 80%) were infested by 823 ticks. The most prevalent tick species was Rhipicephalus microplus (number = 283, 34.3%), followed by Hyalomma anatolicum (223, 27.0%), Rhipicephalus turanicus (122, 14.8%), Haemaphysalis sulcata (104, 12.6%), Haemaphysalis montgomeryi (66, 8.0%), and Haemaphysalis bispinosa (25, 3.03%). A subset of 210 ticks was selected and screened for Rickettsia spp. using PCR-based amplification and subsequent sequencing of rickettsial gltA and ompB fragments. The overall occurrence rate of R. hoogstraalii was 4.3% (number = 9/210). The DNA of Rickettsia was detected in Hy. anatolicum (3/35, 8.5%) and Ha. sulcata (6/49, 12.2%). However, no rickettsial DNA was detected in Rh. microplus (35), Rh. turanicus (35), Ha. montgomeryi (42), and Ha. bispinosa (14). The gltA and ompB fragments showed 99-100% identity with R. hoogstraalii and clustered phylogenetically with the corresponding species from Pakistan, Italy, Georgia, and China. R. hoogstraalii was genetically characterized for the first time in Pakistan and Hy. anatolicum globally. Further studies should be encouraged to determine the role of ticks in the maintenance and transmission of R. hoogstraalii in different hosts.

First report on detection of Hepatozoon ayorgbor in Rhipicephalus haemaphysaloides and Hepatozoon colubri in Haemaphysalis sulcata and Hyalomma anatolicum: risks of spillover of Hepatozoon spp. from wildlife to domestic animals

This study aimed to detect Hepatozoon spp. in ticks infesting asymptomatic domestic animals and to provide insight into their potential spillover from wild to domestic animals. In total, 537 tick specimens were collected in Khyber Pakhtunkhwa, Pakistan, and morphologically identified. The most prevalent tick species was Haemaphysalis cornupunctata (69; 12.8%), followed by Haemaphysalis kashmirensis (62; 11.5%), Rhipicephalus microplus (58; 10.8%), Haemaphysalis montgomeryi (51; 9.5%), Rhipicephalus sanguineus (49; 9.1%), each Haemaphysalis bispinosa and Haemaphysalis sulcata (43; 8.0%), each Hyalomma anatolicum and Rhipicephalus turanicus (37; 6.9%), Rhipicephalus haemaphysaloides (33; 6.1%) Hyalomma scupense (30; 5.6%), and Hyalomma isaaci (25; 4.7%). The extracted DNA from a subset of each tick species was subjected to PCR to amplify 18S rRNA fragments of Hepatozoon spp. By BLAST analysis, the Hepatozoon sp. detected in Hy. anatolicum infesting cows and in Ha. sulcata infesting sheep showed 99.7% maximum identity with Hepatozoon colubri. Similarly, the Hepatozoon sp. detected in R. haemaphysaloides infesting goats shared 99.49% maximum identity with Hepatozoon ayorgbor, and the Hepatozoon sp. detected in R. sanguineus infesting dogs exhibited 99.7% identity with Hepatozoon canis. Having an overall infection rate (9.3%; 16/172), the highest infection rate was recorded for each H. canis, and H. colubri (3.5%; 6/172), followed by H. ayorgbor (2.3%; 4/172). In the phylogenetic tree, H. colubri clustered with corresponding species from Iran, H. ayorgbor clustered with the same species from Croatia, Ghana, and Portugal, and H. canis clustered with the conspecifics from Iran, Israel, Romania, and Zambia. Regarding the potential spillover of Hepatozoon spp. from wildlife through ticks, free ranging animals was at higher risk compared to confined animals (RR = 3.05), animals consuming food from wildlife habitats were at higher risk compared to those consuming domestic food (RR = 3.06), and animals residing in farm buildings located in wildlife habitats were at higher risk compared to those residing in farm buildings located in villages (RR = 3.28). In addition to the first report on H. canis in R. sanguineus in Pakistan, this is the earliest data showing H. ayorgbor in R. haemaphysaloides and H. colubri in Ha. sulcata and Hy. anatolicum. These preliminary findings suggest a potential spillover of Hepatozoon spp. from wild to domestic animals via ticks under certain risk factors.

Association of SFG Rickettsia massiliae and Candidatus Rickettsia shennongii with Different Hard Ticks Infesting Livestock Hosts

Ixodid ticks are responsible for the transmission of various intracellular bacteria, such as the Rickettsia species. Little Information is available about the genetic characterization and epidemiology of Rickettsia spp. The current study was designed to assess the tick species infesting various livestock hosts and the associated Rickettsia spp. in Pakistan. Ticks were collected from different livestock hosts (equids, cattle, buffaloes, sheep, goats, and camels); morphologically identified; and screened for the genetic characterization of Rickettsia spp. by the amplification of partial fragments of the gltA, ompA and ompB genes. Altogether, 707 ticks were collected from 373 infested hosts out of 575 observed hosts. The infested hosts comprised 105 cattle, 71 buffaloes, 70 sheep, 60 goats, 34 camels, and 33 equids. The overall occurrence of Rickettsia spp. was 7.6% (25/330) in the tested ticks. Rickettsia DNA was detected in Rhipicephalus haemaphysaloides (9/50, 18.0%), followed by Rhipicephalus turanicus (13/99, 13.1%), Haemaphysalis cornupunctata (1/18, 5.5%), and Rhipicephalus microplus (2/49, 4.1%); however, no rickettsial DNA was detected in Hyalomma anatolicum (71), Hyalomma dromedarii (35), and Haemaphysalis sulcata (8). Two Rickettsia agents were identified based on partial gltA, ompA, and ompB DNA sequences. The Rickettsia species detected in Rh. haemaphysaloides, Rh. turanicus, and Rh. microplus showed 99-100% identity with Rickettsia sp. and Candidatus Rickettsia shennongii, and in the phylogenetic trees clustered with the corresponding Rickettsia spp. The Rickettsia species detected in Rh. haemaphysaloides, Rh. turanicus, Rh. microplus, and Ha. cornupunctata showed 100% identity with R. massiliae, and in the phylogenetic trees it was clustered with the same species. Candidatus R. shennongii was characterized for the first time in Rh. haemaphysaloides, Rh. turanicus, and Rh. microplus. The presence of SFG Rickettsia spp., including the human pathogen R. massiliae, indicates a zoonotic risk in the study region, thus stressing the need for regular surveillance.

Molecular detection of Coxiella spp. in ticks (Ixodidae and Argasidae) infesting domestic and wild animals: with notes on the epidemiology of tick-borne Coxiella burnetii in Asia

Tick-borne Coxiella spp. are emerging in novel regions infecting different hosts, but information regarding their occurrence is limited. The purpose of this study was the molecular screening of Coxiella spp. in various ticks infesting goats, sheep, camels, cattle, wild mice, and domestic fowls (Gallus gallus domesticus) in various districts of Khyber Pakhtunkhwa, Pakistan. Morphologically identified tick species were confirmed by obtaining their cox1 sequences and were molecularly screened for Coxiella spp. by sequencing GroEL fragments. Almost 345 out of 678 (50.9%) hosts were infested by nine tick species. Regarding the age groups, the hosts having an age >3 years were highly infested (192/345, 55.6%), while gender-wise infestation was higher in female hosts (237/345, 68.7%). In collected ticks, the nymphs were outnumbered (613/1,119, 54.8%), followed by adult females (293/1,119, 26.2%) and males (213/1,119, 19.7%). A total of 227 ticks were processed for molecular identification and detection of Coxiella spp. The obtained cox1 sequences of nine tick species such as Hyalomma dromedarii, Hyalomma anatolicum, Haemaphysalis cornupunctata, Haemaphysalis bispinosa, Haemaphysalis danieli, Haemaphysalis montgomeryi, Rhipicephalus haemaphysaloides, Rhipicephalus microplus, and Argas persicus showed maximum identities between 99.6% and 100% with the same species and in the phylogenetic tree, clustered to the corresponding species. All the tick species except Ha. danieli and R. microplus were found positive for Coxiella spp. (40/227, 17.6%), including Coxiella burnetii (15/40, 6.7%), Coxiella endosymbionts (14/40, 6.3%), and different Coxiella spp. (11/40, 4.9%). By the BLAST results, the GroEL fragments of Coxiella spp. showed maximum identity to C. burnetii, Coxiella endosymbionts, and Coxiella sp., and phylogenetically clustered to the corresponding species. This is the first comprehensive report regarding the genetic characterization of Coxiella spp. in Pakistan's ticks infesting domestic and wild hosts. Proper surveillance and management measures should be undertaken to avoid health risks.