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Anaplasma marginale, a tick-borne obligate intracellular rickettsia is incriminated to cause heavy economic losses throughout the tropical and subtropical regions, including India. However, studies highlighting the phylogeography and demographic dynamics of A. marginale are very scant from India. Thus, the present study assessed the cladistics and population structure of Anaplasma marginale based on the genes encoding the major surface proteins (MSP) 4 and 5. The cladistics based on phylogenetic tree including the sequences generated herein with the GenBank archived sequences of A. marginale was performed. The relationship between A. marginale haplotypes based on both the genetic markers was estimated by performing median joining (MJ) haplotype network analysis. Demographic dynamics involving population diversity indices and neutrality indices was also performed. The cladistics and MJ haplotype network analysis corresponding to both the markers demonstrated the presence of three distinct clades (1-3) of A. marginale. Population structure analysis revealed low nucleotide (0.00236 ± 0.00064 and 0.00955 ± 0.00101) and haplotype (0.321 ± 0.073 and 0.493 ± 0.083) diversities for the MSP4 and MSP5 genes, respectively. High genetic structuring and low gene flow [Nm values ranging between 0.044481 and 0.208337 for the MSP4 gene and 0.032735 (clades 1 and 2) for the MSP5 gene] was also recorded among the different clades of A. marginale, based on both genetic markers. The present study highlighted the presence of different clades of A. marginale distributed worldwide. The isolates circulating in north India belonged to the dominant clade prevalent throughout the globe., Competing Interests: Declaration of Competing Interest Authors declare that they do not have any financial/ non-financial conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Hyalomma anatolicum, an Anatolian hard tick is a well-recognized vector involved in the transmission of various pathogens to animals and humans. The present study elucidated the population structure and haplotype network of H. anatolicum based on the mitochondrial large subunit ribosomal RNA (16S rRNA) gene sequence. The population structure and haplotype network analysis of 75 sequences archived in the GenBank, including the 15 sequences generated herein, yielded 24 haplotypes. Haplotype 1 (Hap_1) was the predominant haplotype consisting of 45 sequences from India, China, Pakistan, Turkey, Egypt, Iraq, and Tajikistan. The complete haplotype network exhibited a stellate conformation, highlighting a recent population expansion. The overall dataset, together with the sequences corresponding to India, China, and Pakistan, showed a high haplotype (0.638 ± 0.065, 0.671 ± 0.103, 0.753 ± 0.099, and 0.854 ± 0.061, respectively) and low nucleotide (0.00407 ± 0.00090, 0.00525 ± 0.00196, 0.00680 ± 0.00233, and 0.00453 ± 0.00056, respectively) diversity, further emphasized a recent population expansion. The neutrality indices including Tajima's D, Fu and Li's D, and Fu and Li's F for the complete dataset (- 2.661, - 6.008, and - 5.649, respectively) as well as for the sequences from India (- 2.223, - 3.414, and - 3.567, respectively) were negative, suggesting deviation from neutrality and a recent population expansion. The present study provided novel insights into the population structure and haplotype networks of H. anatolicum based on the mitochondrial 16S rRNA gene, and the different tests inferred a low genetic differentiation and suggested a recent population expansion of this economically important tick species., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present study had two aims: molecular characterization of Hyalomma dromedarii infesting one-humped camels of Haryana (North India), and assessment of the acaricidal potential of herbal methanolic extracts against H. dromedarii larvae in comparison to synthetic acaricides. Phylogenetics and population neutrality indices were assessed by targeting partial amplification of mitochondrial 16S rDNA sequences. Larval packet test (LPT) was performed to evaluate the acaricidal efficacy of herbal extracts (Ferula asafoetida and Trachyspermum ammi) and synthetic acaricides (deltamethrin and fipronil). Phylogenetic studies established the collected ticks to be H. dromedarii, exhibiting a homology of 99.8–100%. However, the present study isolates formed a different sub-clade compared to H. dromedarii sequences from Egypt, Senegal, Tunisia and Saudi Arabia. Nucleotide and haplotype diversity values were indicative of demographic expansion and low gene flow. Negative values of Tajima's D (-0.612) and Fu and Li's Fst (-0.479) highlighted deviations from neutrality and emphasized recent population expansion. The median lethal concentration (LC50) values recorded for T. ammi, F. asafoetida and their combination were 3.68, 2.87 and 2.59 mg/mL, respectively, whereas the 90% lethal concentration (LC90) values were 4.09, 3.58 and 3.35 mg/mL, respectively. It was also observed that the H. dromedarii population under study was completely susceptible to both the formulated synthetic acaricides. In conclusion, combination of methanolic extracts of F. asafoetida and T. ammi could provide a potential substitute to toxic synthetic chemical acaricides and might prove a valuable component of integrated tick management strategies. [ABSTRACT FROM AUTHOR]

Rhipicephalus microplus , a hematophagous vector prevalent in the tropics and subtropics, is responsible for huge economic losses throughout the globe. However, the taxonomy of the tick species, especially prevalent in north India and south China has been challenged in the recent past. The present study attempted to assess the cryptic status of R. microplus ticks of north India based on two mitochondrial markers; the 16S rRNA and cox 1 gene sequences. The phylogenetic tree corresponding to both markers demonstrated the presence of three distinct genetic assemblages/ clades of R. microplus. The present study isolates (n = five and seven for the cox 1 and 16S rRNA gene sequences, respectively) from north India along with other isolates from India assorted in the R. microplus clade C sensu. Based on the median joining network analysis corresponding to the 16S rRNA gene sequence, 18 haplotypes were recorded, exhibiting a stellate shape, which was indicative of rapid population expansion. For the cox 1 gene, the haplotypes corresponding to clades A, B and C were distantly placed with two exceptions. While performing the population structure analysis, low nucleotide (0.04745 ± 0.00416 and 0.01021 ± 0.00146) and high haplotype diversities (0.913 ± 0.032 and 0.794 ± 0.058) were recorded for the different clades of R. microplus based on the cox 1 and 16S rRNA mitochondrial markers, respectively. Eventually, high genetic differentiation and low gene flow were recorded among the different clades. A negative value for the neutrality indices (Tajima's D = −1.44125, Fu's Fs = −4.879, Fu and Li's D = −2.78031 and Fu and Li's F = −2.75229) corresponding to the 16S rRNA gene for the overall dataset evinced an expansion of population size. Based on the detailed studies, it was inferred that the R. microplus tick species circulating in north India belonged to clade C sensu, similar to that of the species prevalent in the other parts of the country as well as in the Indian subcontinent. • New insight into the phylogeography of R. (B.) microplus ticks circulating in north India. • Cladistics and median joining haplotype network analyses revealed three genetic assemblages/ clades of Rhipicephalus (B.) microplus. • R. (B.) microplus clade C sensu is circulating throughout India (including north India) and the Indian subcontinent. • High genetic differentiation and low gene flow was observed among the clades of R. (B.) microplus. [ABSTRACT FROM AUTHOR]

Bovicola caprae is an important obligate ectoparasite of goats worldwide including India. The present study aimed at the molecular confirmation, phylogenetics and population structure analyses of B. caprae infesting goats of three different agro-climatic locations in India, by targeting the mitochondrial cytochrome C oxidase subunit 1 (cox1) genetic marker. The phylogenetic tree exhibited the presence of two different lineages of B. caprae. The sequences generated herein clustered in lineage 2 along with the GenBank™ archived sequences from China and Iran. The sequences generated herein also showed the circulation of sub-lineages of B. caprae in India based on the analysis of pairwise genetic distances between sequences and median-joining haplotype network. The population structure analyses revealed low nucleotide (0.00353 ± 0.00291 and 0.02694 ± 0.00363) and high haplotype (0.667 ± 0.314 and 0.618 ± 0.104) diversities for the present study isolates as well as for the complete dataset, respectively, which evinced a recent demographic expansion. High genetic differentiation (FST value = 0.97826) and low gene flow (Nm = 0.00556) were also recorded in the different lineages/populations. In conclusion, the present study addressed the research gap and provided the first insight into the phylogenetics of the goat louse B. caprae and highlighted the circulation of sub-lineages of the ectoparasite in India. [ABSTRACT FROM AUTHOR]

• Overall 64 haplotypes of T. annulata were identified based on the cyt b gene. • Only five haplotypes (7.81 %) were shared between any two countries. • Fifty-nine haplotypes (92.19 %) were singleton and unique to one country. • Neutrality indices indicated an expansion in the Indian T. annulata population. • Novel mutations at positions V203I and V219I in cytochrome b gene were observed. The present investigation was aimed at population genetic characterization of Theileria annulata on the basis of the cytochrome b (cyt b) gene along with the evaluation of status of buparvaquone resistance in Haryana (India). The sequences originating from China, Egypt, India, Iran, Iraq, Tunisia, Turkey and Sudan were included in the analysis. The maximum likelihood tree based on the Tamura-Nei (TN93+G) model placed all the sequences of T. annulata into a single clade. The median-joining haplotype network exemplified geographical clustering between T. annulata haplotypes originating from each country. Only five haplotypes (7.81 %) were shared between any two countries, while the remaining 59 haplotypes (92.19 %) were singleton and unique to one country. The values of pairwise genetic distance (F ST) between all the populations indicated huge genetic differentiation (> 0.25) between different T. annulata populations, barring the F ST value between Iraq and Turkey (0.14454) which suggested a moderate differentiation. Contrary to the F ST index, the values of gene flow (Nm) between T. annulata populations were very low. The neutrality indices and mismatch distributions indicated a population expansion in the Indian T. annulata population. Furthermore, the secondary structure and homology modeling of the partial cyt b protein is also reported. The molecular analysis of newly generated sequences for buparvaquone resistance revealed that all the isolates were susceptible to buparvaquone treatment. However, two novel mutations at positions V203I and V219I in between the Q01 and Q02 drug-binding regions of the cyt b gene were observed for the first time. [ABSTRACT FROM AUTHOR]

The present study was conducted to elucidate the population genetic diversity and haplotype network of Theileria annulata based on all available nearly complete 18S rRNA gene sequences in the GenBank™. In total, 52 sequences of the nuclear 18S rRNA gene used to assess the relationship of T. annulata with their country of origin identified 34 haplotypes. Haplotype 4 was widespread, occurring in India, China, Turkey and Iran, while the remaining haplotypes were singleton and unique to one country. Haplotype 4 displayed numerous single haplotypes around it and the stellate shape of the network suggested a rapid population expansion. India exhibited the largest number of haplotypes (h = 25) followed by Turkey (h = 6), China (h = 4), and Iran and Italy (h = 1). No geographical clustering of haplotypes was recorded. Nucleotide diversity was the highest in the Turkish followed by the Indian and Chinese populations. Similarly, haplotype diversity was the highest in China followed by Turkey, and the lowest in India. The overall dataset exhibited a low nucleotide diversity (0.00253 ± 0.00035), but high haplotype diversity (0.917 ± 0.034). It suggested the presence of only minor differences (01–11 nucleotide) between haplotypes which was also evident from the haplotype network. A high level of genetic diversity was documented within the Indian, Chinese and Turkish populations of T. annulata , whereas little genetic differentiation was noticed among these populations with a very high level of gene flow. Analysis of molecular variance (AMOVA) of T. annulata sequences revealed higher genetic variation within countries (83.58%) as compared to the variation among countries (16.42%). Neutrality indices, viz., Tajima's D, Fu and Li's F, Fu's F s , and R 2, along with the unimodal mismatch distributions demonstrated a recent population expansion of T. annulata in India and the overall dataset. However, the non-significant values of Tajima's D, Fu and Li's F, and Fu's F s for the Chinese population along with a bimodal mismatch distribution signified a constant population size. For the Turkish population, the neutrality and mismatch distribution tests either indicated a constant or a slight increase in population size. The present study provides novel insights into the population genetics and haplotype network of T. annulata based on the 18S rRNA gene for the first time. [Display omitted] • First study on the population structure and haplotype analysis of T. annulata based on 18S rRNA gene. • Overall 34 haplotypes of T. annulata were identified based on the 18S rRNA gene. • Haplotype 4 was widespread, occurring in India, China, Turkey and Iran. • Remaining 33 haplotypes were singleton and unique to one country. • Haplotype diversity was the highest in China followed by Turkey and India. • Neutrality indices showed population expansion in India and the overall dataset. [ABSTRACT FROM AUTHOR]