scholarly journals Molecular characterization of Ribosomal DNA (ITS2) of hard ticks in Iran: understanding the conspecificity of Dermacentor marginatus and D. niveus

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Parisa Soltan-Alinejad ◽  
Zahra Ramezani ◽  
Hamideh Edalat ◽  
Zakkyeh Telmadarraiy ◽  
Farrokh Dabiri ◽  
...  

Abstract Objectives Hard ticks (Acari: Ixodidae) are ectoparasites of medical and veterinary importance. They are obligate blood-feeding vectors with the ability to transmit a wide variety of pathogens. Standard morphological keys are normally used for the identification of tick species. However, considering the importance of accurate species identification and the determination of bio-ecological characteristics of species, relying on morphological keys alone can be questionable. In this study, two DNA fragments (ITS2 and COI) were selected for phylogenetic evaluation of Iranian hard tick species belonging to the genera Dermacentor, Hyalomma, and Rhipicephalus. Results 1229 specimens of Dermacentor marginatus, D. niveus, Hyalomma anatolicum, Rhipicephalus bursa, and R. sanguineuss.l constituting 11 populations were collected from three different climatic and zoogeographical zones in Iran. Morphological studies revealed notable differences in important morphological characteristics between different populations of D. marginatus. The results of ITS2 sequence analysis provided additional evidence which supports the conspecificity of D. niveus and D. marginatus. Contrary to this finding, the sequence analysis of COI and phylogeny favored the separation of the two species. Given the greater importance of COI in identifying and discriminating species, a possibility heterospecificity between the two species should be considered.

2020 ◽  
Author(s):  
Parisa Soltan-Alinejad ◽  
Zahra Ramezani ◽  
Hamideh Edalat ◽  
Zakkyeh Telmadarraiy ◽  
Farrokh Dabiri ◽  
...  

Abstract Objectives: Hard ticks (Acari: Ixodidae) are ectoparasites of medical and veterinary importance. They are obligate blood-feeding vectors with the ability to transmit a wide variety of pathogens. Standard morphological keys are normally used for the identification of tick species. However, considering the importance of accurate species identification and the determination of bio-ecological characteristics of species, relying on morphological keys alone can be questionable. In this study, two DNA fragments (ITS2 and COI) were selected for phylogenetic evaluation of Iranian hard tick species belonging to the genera Dermacentor, Hyalomma, and Rhipicephalus. Results: 1229 specimens of Dermacentor marginatus, D. niveus, Hyalomma anatolicum, Rhipicephalus bursa, and R. sanguineus constituting 11 populations were collected from three different climatic and zoogeographical zones in Iran. Morphological studies revealed notable differences in important morphological characteristics between different populations of D. marginatus.The results of ITS2 sequence analysis provided additional evidence which supports the conspecificity of D. niveus and D. marginatus. Contrary to this finding, the sequence analysis of COI and phylogeny favored the separation of the two species. Given the greater importance of COI in identifying and discriminating species, a possibility heterospecificity between the two species should be considered.


2020 ◽  
Author(s):  
Parisa Soltan-Alinejad ◽  
Zahra Ramezani ◽  
Hamideh Edalat ◽  
Zakkyeh Telmadarraiy ◽  
Farrokh Dabiri ◽  
...  

Abstract Objectives: Hard ticks (Acari: Ixodidae) are ectoparasites of human and animals and transmit a wide range of pathogens. The species identification of ticks is normally based on morphological keys. However, considering the importance of proper identification of the species and their bio-ecological characteristics, relying on morphological characteristics alone can be questionable. In this study, ITS2 and COI were selected for phylogenetic evaluation of Iranian species belonging to three genera: Dermacentor, Hyalomma and Rhipicephalus. Results: The ticks were from 10 populations from three different climatic and zoogeographical zones of Iran. The study of important morphological characteristics revealed notable differences in these characteristics between different populations of D. marginatus species.Contrary to the results of ITS2 sequence analysis which giving additional support for the view that D. niveus and D. marginatus should be viewed as one species only, the sequence analysis of COI and phylogeny favored the separation of the two species of D. niveus and D. marginatus. Given the greater importance of COI in identifying and distinguishing species, the Being two species should be considered.


2012 ◽  
Vol 103 (2) ◽  
pp. 216-224 ◽  
Author(s):  
S. Nava ◽  
A.A. Guglielmone

AbstractHost specificity of Neotropical hard ticks (Acari: Ixodidae) was analyzed by using the number of hosts species for each tick species and the index of host specificity STD*, which integrates phylogenetic and ecological information. The analyses were based on 4172 records of hard ticks collected from wild and domestic tetrapods. Most tick species included in this study were associated with three to 20 host species. No tick species has been associated either with a single species or with a single genus of host. It was found that the number of host species is sensitive to sampling effort, but not the STD*. The most frequent values of STD* were between 2.5 and 3.5, which shows that the host species more frequently used by Neotropical hard tick species belong to different families or different orders. Immature stages tend to use a broader taxonomic range of hosts than adults, and the interpretation of both measures of host specificity used in this study led to the conclusion that the impact of non-endemic hosts does not alter the patterns of host specificity in Neotropical hard ticks. The index STD* showed that a high proportion of tick species has phylogenetically unrelated species as principal hosts. The conclusion reached in this work indicates that strict host specificity is not common among Neotropical hard ticks and suggests that the influence of tick ecology and evolution of habitat specificity, tick generation time, phenology, time spent off the host and the type of life-cycle could be more important than hosts species.


2020 ◽  
Author(s):  
Rolando A. Gittens ◽  
Alejandro Almanza ◽  
Eric Álvarez ◽  
Kelly L. Bennett ◽  
Luis C. Mejía ◽  
...  

AbstractMatrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry is an analytical method that detects macromolecules that can be used as biomarkers for taxonomic identification in arthropods. The conventional MALDI approach uses fresh laboratory-reared arthropod specimens to build a reference mass spectra library with high-quality standards required to achieve reliable identification. However, this may not be possible to accomplish in some arthropod groups that are difficult to rear under laboratory conditions, or for which only alcohol preserved samples are available. Here, we generated MALDI mass spectra of highly abundant proteins from the legs of 18 Neotropical species of adult field-collected hard ticks, several of which had not been analyzed by mass spectrometry before. We then used their mass spectra as fingerprints to identify each tick species by applying machine learning and pattern recognition algorithms that combined unsupervised and supervised clustering approaches. Both principal component analysis (PCA) and linear discriminant analysis (LDA) classification algorithms were able to identify spectra from different tick species, with LDA achieving the best performance when applied to field-collected specimens that did have an existing entry in a reference library of arthropod protein spectra. These findings contribute to the growing literature that ascertains mass spectrometry as a rapid and effective method for taxonomic identification of disease vectors, which is the first step to predict and manage arthropod-borne pathogens.Author SummaryHard ticks (Ixodidae) are external parasites that feed on the blood of almost every species of terrestrial vertebrate on earth, including humans. Due to a complete dependency on blood, both sexes and even immature stages, are capable of transmitting disease agents to their hosts, causing distress and sometimes death. Despite the public health significance of ixodid ticks, accurate species identification remains problematic. Vector species identification is core to developing effective vector control schemes. Herein, we provide the first report of MALDI identification of several species of field-collected Neotropical tick specimens preserved in ethanol for up to four years. Our methodology shows that identification does not depend on a commercial reference library of lab-reared samples, but with the help of machine learning it can rely on a self-curated reference library. In addition, our approach offers greater accuracy and lower cost per sample than conventional and modern identification approaches such as morphology and molecular barcoding.


2021 ◽  
Vol 8 (3) ◽  
pp. 36
Author(s):  
Donath Damian ◽  
Modester Damas ◽  
Jonas Johansson Wensman ◽  
Mikael Berg

Ticks are one of the most important arthropod vectors and reservoirs as they harbor a wide variety of viruses, bacteria, fungi, protozoa, and nematodes, which can cause diseases in human and livestock. Due to their impact on human, livestock, and wild animal health, increased knowledge of ticks is needed. So far, the published data on the molecular diversity between hard ticks species collected in Tanzania is scarce. The objective of this study was to determine the genetic diversity between hard tick species collected in the wildlife-livestock interface ecosystem at Mikumi National Park, Tanzania using the mitochondrion 16S rRNA gene sequences. Adult ticks were collected from cattle (632 ticks), goats (187 ticks), and environment (28 ticks) in the wards which lie at the border of Mikumi National Park. Morphological identification of ticks was performed to genus level. To identify ticks to species level, molecular analysis based on mitochondrion 16S rRNA gene was performed. Ticks representing the two genera (Hyalomma and Rhipicephalus) were identified using morphological characters. Six species were confirmed based on mitochondrion 16S rRNA gene, including Rhipicephalus microplus, Rhipicephalus evertsi, Hyalomma rufipes, Hyalomma truncatum, Hyalomma marginatum, and Hhyalomma turanicum. The presence of different clusters of tick species reflects the possible biological diversity of the hard ticks present in the study region. Further studies are however required to quantify species of hard ticks present in the study region and the country in general over a larger scale.


2017 ◽  
Vol 43 (2) ◽  
pp. 268
Author(s):  
Fredy A. Rivera-Páez ◽  
Marcelo B. Labruna ◽  
Thiago F. Martins ◽  
Bruno Rodrigues-Sampieri ◽  
María I. Camargo-Mathias

Gynandromorphism is a condition in which an organism simultaneously exhibits male and female morphological characteristics. In Colombia, the taxon Amblyomma cajennense is represented by the species Amblyomma patinoi and Amblyomma mixtum. In September of 2014, in the Colombian Orinoco region, adult ticks were collected and determined from natural infections in bovines and equines. A gynandromorph was described from a natural infestation on a bovine, and morphologically classified as A. mixtum. This is the first literature report of a gynandromorph of A. mixtum, and the first description of a gynandromorph for a tick species in Colombia.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 230
Author(s):  
ThankGod E. Onyiche ◽  
Cristian Răileanu ◽  
Susanne Fischer ◽  
Cornelia Silaghi

Babesiosis caused by the Babesia species is a parasitic tick-borne disease. It threatens many mammalian species and is transmitted through infected ixodid ticks. To date, the global occurrence and distribution are poorly understood in questing ticks. Therefore, we performed a meta-analysis to estimate the distribution of the pathogen. A deep search for four electronic databases of the published literature investigating the prevalence of Babesia spp. in questing ticks was undertaken and obtained data analyzed. Our results indicate that in 104 eligible studies dating from 1985 to 2020, altogether 137,364 ticks were screened with 3069 positives with an estimated global pooled prevalence estimates (PPE) of 2.10%. In total, 19 different Babesia species of both human and veterinary importance were detected in 23 tick species, with Babesia microti and Ixodesricinus being the most widely reported Babesia and tick species, respectively. Regardless of species, adult ticks with 2.60% had the highest infection rates, while larvae had the least with 0.60%. Similarly, female ticks with 4.90% were infected compared to males with 3.80%. Nested-polymerase chain reaction (PCR) 2.80% had the highest prevalence among the molecular techniques employed. In conclusion, results obtained indicate that Babesia species are present in diverse questing tick species at a low prevalence, of which some are competent vectors.


Author(s):  
M. Götz ◽  
U. Braun

AbstractGolovinomyces longipes is a widespread powdery mildew on Solanaceae (Nicotiana, Petunia and Solanum spp.). In the past, it has been reported only once on Verbena (Verbenaceae), a non-solanaceaous host. Recently, this powdery mildew has been found on the composite Matricaria chamomilla. The identification of the powdery mildew species on this unusual host has been proved by morphological studies and DNA sequence analysis. Both datasets coincide with the characteristic data for G. longipes on Solanaceae. First inoculation experiments with further composites resulted in an infection of Brachyscome hybrid ‘Surdaisy’. To our knowledge, this is the first report of G. lonigpes on hosts belonging to the important family of Asteraceae and an additional proof of the broader host range of G. longipes beyond the Solanaceae.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Congzhao Fan ◽  
Xiaojin Li ◽  
Jun Zhu ◽  
Jingyuan Song ◽  
Hui Yao

The medicinal plantFerulahas been widely used in Asian medicine, especially in Uyghur medicine in Xinjiang, China. Given that various substitutes and closely related species have similar morphological characteristics,Ferulais difficult to distinguish based on morphology alone, thereby causing confusion and threatening the safe use ofFerula. In this study, internal transcribed spacer 2 (ITS2) sequences were analyzed and assessed for the accurate identification of two salableFerulaspecies (Ferula sinkiangensisandFerula fukangensis) and eight substitutes or closely related species. Results showed that the sequence length of ITS2 ranged from 451 bp to 45 bp, whereas guanine and cytosine contents (GC) were from 53.6% to 56.2%. A total of 77 variation sites were detected, including 63 base mutations and 14 insertion/deletion mutations. The ITS2 sequence correctly identified 100% of the samples at the species level using the basic local alignment search tool 1 and nearest-distance method. Furthermore, neighbor-joining tree successfully identified the genuine plantsF. sinkiangensisandF. fukangensisfrom their succedaneum and closely related species. These results indicated that ITS2 sequence could be used as a valuable barcode to distinguish Uyghur medicineFerulafrom counterfeits and closely related species. This study may broaden DNA barcoding application in the Uyghur medicinal plant field.


2015 ◽  
Vol 39 ◽  
pp. 256-262 ◽  
Author(s):  
Olcay HEKİMOĞLU ◽  
Ayşe Nurdan ÖZER
Keyword(s):  

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