Novel Social Stimulation Ameliorates Memory Deficit in Alzheimer's Disease Model through Activating α-Secretase.

As the most common form of dementia in the world, Alzheimer's disease (AD) is a progressive neurological disorder marked by cognitive and behavioral impairment. According to previous researches, abundant social connections shield against dementia. However, it is still unclear how exactly social interactions benefit cognitive abilities in people with AD and how this process is used to increase their general cognitive performance. In this study, we found that single novel social (SNS) stimulation promoted c-Fos expression and increased the protein levels of mature ADAM10/17 and sAPPα in the ventral hippocampus (vHPC) of wild-type (WT) mice, which are hippocampal dorsal CA2 (dCA2) neuron activity and vHPC NMDAR dependent. Additionally, we discovered that SNS caused similar changes in an AD model, FAD4T mice, and these alterations could be reversed by α-secretase inhibitor. Furthermore, we also found that multiple novel social (MNS) stimulation improved synaptic plasticity and memory impairments in both male and female FAD4T mice, accompanied by α-secretase activation and Aß reduction. These findings provide insight into the process underpinning how social interaction helps AD patients who are experiencing cognitive decline, and we also imply that novel social interaction and activation of the α-secretase may be preventative and therapeutic in the early stages of AD.

Joint toxicity of insecticides against Hyalomma asiaticum.

Hyalomma asiaticum, a hematophagous ectoparasite, causes severe economic losses. We studied the acute toxicity of five pesticides (three single-agent and two combination preparations) to this organism. Engorged larval ticks were immersed in ten serial concentrations of each insecticide and observed for 20 days. The LC50 values of the five insecticides and the cotoxicity coefficients (CTCs) of the two mixtures were estimated for H. asiaticum. The CTCs of lambda-cyhalothrin + etoxazole and lambda-cyhalothrin + fipronil were 128.83 and 331.58, respectively, each demonstrating synergism. The results indicated that these two mixtures were more effective than individual insecticides, and this study suggests a substitutional approach to the control of ticks.

Mitochondrial genome of Theileria uilenbergi endemic in sheep and goats in China.

Mitochondrial genomes provide new insights that help elucidating biological features, genetic evolution, and classification of protozoans. Theileria uilenbergi (T. uilenbergi), transmitted by Haemaphysalis qinghaiensis and H. longicornis, is considered as highly pathogenic to sheep and goats in China. This study reports and outlines features of its mitochondrial genome. The T. uilenbergi mitochondrial genome is a linear monomeric molecule of 6.0 kb length, which encodes three protein-coding genes named cytochrome c oxidase I (cox1), cytochrome b (cob), and cytochrome c oxidase III (cox3), as well as six large subunit (LSU) rRNA gene fragments, and ends in terminal inverted repeats (TIRs). The array structure and organization of the mitochondrial genome of T. uilenbergi is identical to that of T. parva. Phylogenetic analysis based on the amino acid sequences of cox1, cob, and cox3 genes suggests that T. uilenbergi is distantly related to the group of transforming Theileria species such as T. parva. This study contributes to a comprehensive understanding of the phylogeny and evolution of the mitochondrial genome of piroplasms and provides useful information of diagnostic marker for T. uilenbergi.

Coxiella burnetii is widespread in ticks (Ixodidae) in the Xinjiang areas of China.

BACKGROUND: The gram-negative Coxiella burnetii bacterium is the pathogen that causes Q fever. The bacterium is transmitted to animals via ticks, and manure, air, dead infected animals, etc. and can cause infection in domestic animals, wild animals, and humans. Xinjiang, the provincial-level administrative region with the largest land area in China, has many endemic tick species. The infection rate of C. burnetii in ticks in Xinjiang border areas has not been studied in detail. RESULTS: For the current study, 1507 ticks were collected from livestock at 22 sampling sites in ten border regions of the Xinjiang Uygur Autonomous region from 2018 to 2019. C. burnetii was detected in 205/348 (58.91%) Dermacentor nuttalli; in 110/146 (75.34%) D. pavlovskyi; in 66/80 (82.50%) D. silvarum; in 15/32 (46.90%) D. niveus; in 28/132 (21.21%) Hyalomma rufipes; in 24/25 (96.00%) H. anatolicum; in 219/312 (70.19%) H. asiaticum; in 252/338 (74.56%) Rhipicephalus sanguineus; and in 54/92 (58.70%) Haemaphysalis punctata. Among these samples, C. burnetii was detected in D. pavlovskyi for the first time. The infection rate of Rhipicephalus was 74.56% (252/338), which was the highest among the four tick genera sampled, whereas the infection rate of H. anatolicum was 96% (24/25), which was the highest among the nine tick species sampled. A sequence analysis indicated that 63 16S rRNA sequences could be found in four newly established genotypes: MT498683.1 (n = 18), MT498684.1 (n = 33), MT498685.1 (n = 6), and MT498686.1 (n = 6). CONCLUSIONS: This study indicates that MT498684.1 might represent the main C. burnetii genotype in the ticks in Xinjiang because it was detected in eight of the tick species studied. The high infection rate of C. burnetii detected in the ticks found in domestic animals may indicate a high likelihood of Q fever infection in both domestic animals and humans.

Ultrasound-assisted extraction extracts from Stemona japonica (Blume) Miq. and Cnidium monnieri (L.) Cuss. could be used as potential Rhipicephalus sanguineus control agents.

Nicotiana tabacum, Stemona japonica, and Cnidium monnieri are common plants that are widely used for their anti-parasitic properties. The purpose of this study was to evaluate the acaricidal activity of extracts from these plants against the brown dog tick, Rhipicephalus sanguineus. A composition analysis of crude extracts by GC-MS was conducted to discover compounds with acaricidal effects. The toxicity of extraction against the engorged nymphs of R. sanguineus was evaluated by an immersion test. The results showed that the crude extracts of S. japonica and C. monnieri in varying ratios, concentrations, and from different extraction methods, had a killing effect on R. sanguineus. Lethality reached 76.67% ± 0.04410 when using a 1:1 extract of S. japonica:C. monnieri in 75% ethanol with ultrasonic extraction; the crude extract was determined at a concentration of 0.5 g/mL. GC-MS results showed that osthole and 5-hydroxymethylfurfural (5-HMF) are the main components of the extract. These results suggested that ultrasound-assisted extraction (UAE) extracts contained acaricidal components acting against R. sanguineus, which may result in the development of effective extracts of S. japonica and C. monnieri as a source of low-toxicity, plant-based, natural acaricidal drugs.

Molecular detection and genetic diversity of Theileria orientalis in cattle in China.

The apicomplexan parasite Theileria orientalis is a tick-borne intracellular protozoan parasite that is widely distributed throughout China. It causes bovine theileriosis in infected cattle, which results in huge economic losses to the cattle industry. In this study, the infection status of T. orientalis was determined in 260 blood samples from cattle from seven provinces across China. Results of a major piroplasm surface protein (MPSP)-PCR assay revealed that an average of 36.5% (95/260) of cattle was positive for T. orientalis infection. Based on the MPSP gene sequences, phylogenetic analysis revealed that these isolates of T. orientalis comprised of eight MPSP types, 1, 2, 3, 4, 5, 7, N1, and N2. This is the first report of new T. orientalis MPSP genotypes N1 and N2 in cattle in China.

Genetic diversity of Haemaphysalis qinghaiensis (Acari: Ixodidae) in western China.

Haemaphysalis qinghaiensis as an endemic species in China mainly infests domestic animals and causes great harm to animals and humans in Northwestern plateau. However, there is no information about genetic diversity within the recently established populations of this tick species. Therefore, the present study analyzed the fragments of mitochondrial 16S rDNA, COI and the nuclear gene ITS1 of 56 H. qinghaiensis ticks across four regions of China which are main endemic areas of this species. Analysis showed 98.1-100% (16S rDNA), 97.9-100% (COI), 99.7-100% (ITS1) identity within individuals. For these sequences, 9, 15 and 8 haplotypes were found for 16S rDNA, COI and ITS1, respectively. Ticks from Yongjing were the most variable group, followed by Lintan, Huangyuan, and Tianzhu. Based on parallel analysis of the mitochondrial and nuclear genetic diversity of H. qinghaiensis, our results indicated that mitochondrial markers (especially COI) were much more useful than nuclear ITS for intraspecific genetic variability analysis.

Comparative proteomic and bioinformatic analysis of Theileria luwenshuni and Theileria uilenbergi.

Theileria is an obligatory intraerythrocytic protozoan parasite that causes economic losses to the cattle, sheep and goats industry. However, very little information is available on the genomes, transcriptomes, and proteomes of the ovine parasites, Theileria luwenshuni and Theileria uilenbergi. Differences in protein expression between these species were investigated to better understand their biology. Parasites were digested with trypsin, and the resulting peptides labeled with isobaric tags for relative and absolute quantification, followed by LC-MS/MS. More than 670 proteins, classified into categories primarily related to cellular process (29.78%), metabolic process (28.80%), localization (5.22%) and biological regulation (5.00%), were identified. Seventy-one proteins were differentially expressed; T. luwenshuni had 39 proteins more highly expressed than in T. uilenbergi, whereas T. uilenbergi had 32 that were more highly expressed. Several proteins related to parasite virulence and invasion (cysteine proteinase, histone deacetylase, pyruvate kinase, small nuclear ribonucleoprotein and orotate phosphoribosyltransferase) were differentially expressed. Real-time quantitative PCR validated protein expression changes at the transcript level. This is the first report on protein expression for the two most economically important Theileria species in China, and our findings may provide novel opportunities for ovine and caprine theileriosis control.

An indirect ELISA for detection of Theileria spp. antibodies using a recombinant protein (rTlSP) from Theileria luwenshuni.

Theileria is a tick-borne, intracellular protozoan parasite of worldwide economic and veterinary importance in small ruminants. Here, an enzyme-linked immunosorbent assay (ELISA) was developed based on Theileria luwenshuni recombinant surface protein (rTlSP) and was used in the standardization and validation of an ELISA for the detection of circulating antibodies against ovine and caprine theileriosis. A total of 233 sera samples were used for the calculation of the cut-off value which served as a threshold between the positive and the negative sera. When the positive threshold was chosen as 19% of the specific mean antibody rate, the specificity was 97.9%, and the sensitivity was 97.1%. There was a cross-reaction with sera against Theileria uilenbergi and Theileria ovis, and no cross-reaction with sera against Babesia spp. in the ELISA and Western blotting. Two hundred forty samples collected from sheep in Gansu province were detected with blood smears and ELISA, respectively. The results showed that the positive rate of Theileria infection in Gansu province were 63.75% with rTlSP-ELISA, and 46.67% with blood smears, respectively. Our test proved that the rTlSP ELISA is suitable to diagnose Theileria infection and could be used in serological surveys to map out the prevalence of ovine and caprine theileriosis.

Abnormal Development of Haemaphysalis qinghaiensis (Acari: Ixodidae).

A single Haemaphysalis qinghaiensis specimen exhibiting abnormal morphology was collected from a tick laboratory colony. The tick had a heart-shaped body with partial twinning of the posterior region (with two anal orifices and two genital grooves). To the best of our knowledge, this is the first report of teratological changes in H. qinghaiensis The abnormal morphological features are described herein.

Laboratory evaluation of Beauveria bassiana and Metarhizium anisopliae in the control of Haemaphysalis qinghaiensis in China.

Haemaphysalis qinghaiensis, a prevalent tick species in China, is an ectoparasite that preferentially infests small ruminants and can transmit Theileria sp. and Babesia sp. In this study, we evaluated the pathogenicity of individual and mixed infections of the fungi Beauveria bassiana and Metarhizium anisopliae to H. qinghaiensis nymphs. The estimated LC50 for ticks immersed in solutions of B. bassiana, M. anisopliae and a mixture thereof were: 5.88056 × 10(4), 2.65 × 10(4), and 2.85 × 10(4) conidia mL(-1) respectively, and the nymphal mortality ranged from 52 to 100 %. Thus, these results suggest a potential approach for the biocontrol of H. qinghaiensis.

Biological Parameters of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Fed on Rabbits, Sheep, and Cattle.

In order to determine the effect of various hosts on feeding performance of Rhipicephalus (Boophilus) microplus, we used 3 mammalian species as hosts, cattle (Qinchuan), sheep (T an), and rabbits (Japanese white rabbit) for infest-ing ticks. Five hundreds of R. microplus larvae were exposed to each animal (3 animals/host species). Tick recoveries were 11.0%, 0.47%, and 5.5% from cattle, sheep, and rabbits, respectively. The averages of tick feeding periods were not significantly different on cattle, sheep, and rabbits, 28.8, 25.3, and 26.7 days, respectively. The average weights of individual engorged female from cattle, sheep, and rabbits were 312.5, 219.1, and 130.2 mg, respectively and those of egg mass weights each to 85.0, 96.6, and 17.8 mg. The highest egg hatching rate was in the ticks from cattle (96.0%), fol-lowed by those from rabbits (83.0%) and sheep (19.2%). These data suggest that rabbits could be as an alternative host to cultivate R. microplus for evaluating vaccines and chemical and biological medicines against the tick in the laboratory, although the biological parameters of ticks were less than those from cattle.

The efficacies of 5 insecticides against hard ticks Hyalomma asiaticum, Haemaphysalis longicornis and Rhipicephalus sanguineus.

At present, chemical-based tick control strategies are still the most efficient and widely used methods in control of ticks and tick-borne diseases. In this study, the efficacies of lambda-cyhalothrin, beta-cypermethrin, emamectin benzoate, spirotetramat and hexaflumuron in vitro were evaluated against Hyalomma asiaticum, Haemaphysalis longicornis and Rhipicephalus sanguineus that are widespread and able to transmit a variety of human and animal diseases in China. The results showed that the LC (lethal concentration) 50 of lambda-cyhalothrin, beta-cypermethrin, emamectin benzoate, spirotetramat and hexaflumuron were 22.05, 107.35, 287.62, 432.25 and over 6250 mg/L to Hy. asiaticum engorged nymphs, respectively. The LC50 of lambda-cyhalothrin and beta-cypermethrin were each to 100.69 mg/L and 340.05 mg/L against Hy. asiaticum unfed adults. In addition, 50 mg/L of lambda-cyhalothrin could completely inhibit engorged females of the 3 tick species to lay eggs. These results indicate that lambda-cyhalothrin has the highest efficacy and broadest spectrum for against the 3 tick species. The present study provides some information for selecting chemical acaricides in control ticks and tick-borne-diseases, as well for preparing acaricide mixtures to improve killing efficacy, and retard the advent of tick-resistance of acaricides in China.

Does Haemaphysalis bispinosa (Acari: Ixodidae) really occur in China?

Haemaphysalis bispinosa Neumann has been considered to exist in China, especially in the southern part of the country. However, H. bispinosa referred to in many Chinese research papers may in fact be H. longicornis, which is widely distributed in most regions of China. In order to clarify the occurrence of H. bispinosa, Haemaphysalis ticks collected from 18 of 23 provinces of China (Hebei, Henan, Hubei, Guangxi, Gansu, Yunnan, Xinjiang, Anhui, Zhejiang, Shannxi, Guizhou, Sichuan, Shanxi, Shandong, Ningxia, Fujian, Qinghai and Jiangxi) were examined based on morphological and molecular characteristics. We found no evidence of H. bispinosa being present in China. Our results indicate that all of the so called "H. bispinosa" ticks reported in China are in fact H. longicornis.

Morphological Characteristics of Normal and Gynandromorphic Hyalomma asiaticum Schulze and Schlottke, 1930.

Gynandromorphic ticks are extremely rare, and often attract parasitologists' attention. During our examination of tick specimens, an engorged gynandromorph of Hyalomma asiaticum was noticed. This is the first record of gynandromorphic ticks from China. In this study, several important morphological structures of normal and gynandromorphic H. asiaticum were analyzed. Comparing to the normal H. asiaticum, the gynandromorphic specimen was a typical bipartite protogynander. Its right side showed normal female characteristics, whereas the left side had normal male traits. Different from other gynandromorphic ticks containing 1 anus, this tick reported here had 2 complete anuses, and the anus of the male part had a single adanal plate.

Scanning electron microscopy of all parasitic stages of Haemaphysalis qinghaiensis Teng, 1980 (Acari: Ixodidae).

Haemaphysalis qinghaiensis Teng (Acta Zootaxon Sin 5:144-149, 1980) is an endemic species in China. This tick species was first described based on engorged or semi-engorged specimens, and the drawings and description in words of morphological characteristics were poor. Therefore, the present study aims to redescribe morphological characteristics of all active stages of this tick species in detail by scanning electron microscopy. Additionally, a comparison between H. qinghaiensis and other sympatric Haemaphysalis species was also analyzed. Males of H. qinghaiensis can be distinguished from sympatric Haemaphysalis species by the following characters: palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; the tips of palpal segment III not so strongly recurved inward to become "pincerlike" and lacking dorsal spur; dental formula 5/5; lateral grooves enclose first festoon; coxa IV with a short, broadly triangular spur; tarsi somewhat humped; and spiracular plates long comma-shaped. Females of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; segment III of palpi lacking dorsal spur; dental formula 4/4; scutum subcircula; and tarsi somewhat humped. Nymphs of H. qinghaiensis can be distinguished from those of other species by palpi less salient laterally and curved in contour; dental formula 2/2; basis capituli rectangular, with distinct dorsal cornua, without ventral cornua; and spiracular plates with short and narrow dorsal prolongation. Larvae of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; basis capituli rectangular, without distinct cornua.

Dermacentor everestianus Hirst, 1926 (Acari: Ixodidae): phylogenetic status inferred from molecular characteristics.

Dermacentor everestianus Hirst, 1926, is only reported in Northwestern China and Nepal. Few researches about this species have been involved, especially for molecular characteristics. The taxonomy studies of D.everestianus are mainly based on morphological features, and its taxonomic status is an ongoing controversy. To clarify the molecular characteristics and phylogenetic status of D.everestianus and other related species, the sequences of mitochondrial 16S ribosomal DNA (rDNA) and cox1 fragments were analyzed in the present study. Analysis of 16S rDNA and cox1 sequences showed 99.3-100% identity within D.everestianus individuals, with the genetic divergence among them was 0-0.0086. The interspecific distance of 16S rDNA and cox1 between D.everestianus and some other Palaearctic species including D. silvarum, D. nuttalli, and D. marginatus was much smaller than that between D.everestianus and Nearctic Dermacentor ticks (D.albipictus, D.nitens, and D.variabilis). Such relationships of these ticks were also verified in the phylogenetic analysis. Two major clades were recovered within Dermacentor spp. with more than 90% bootstrap support in the phylogenetic trees. D.everestianus together with D.silvarum, D.nuttalli, and D.marginatus were included in the clade I (Eurasia lineage). Other analyzed tick species including D.variabilis, D.nitens, and D.albipictus formed clade II, which are distributed in Nearctic realm. These indicated that the genus Dermacentor was at least composed of two lineages. Thus, further researches including additionally molecular markers on all Dermacentor species globally should be taken to precisely resolve relationships within Dermacentor.

Multiplex PCR for diagnosis of Theileria uilenbergi, Theileria luwenshuni, and Theileria ovis in small ruminants.

Infections with Theileria sp. may cause significant economic losses to the sheep industry. Species identification based on microscopic examination is difficult, and more suitable methods are required for the rapid detection and identification of Theileria sp, in clinical specimens. In this study, a multiplex polymerase chain reaction (mPCR) assay was developed to simultaneously identify three individual Theileria species in small ruminants. Three pairs of specific, sensitive primers were designed on the basis of the 5.8S ribosomal RNA gene (Theileria luwenshuni and Theileria ovis) and the 18S ribosomal RNA gene (Theileria uilenbergi) to generate target products of 303, 884, and 530 bp, respectively. Standard DNA for each of the three species was extracted from blood recovered from infected sheep, and a preliminary study was conducted on 56 sheep to verify the reliability of the system. Optimal PCR conditions, including primer concentration, annealing time, and the number of amplification cycles, were established. The assay sensitivity under these conditions was 10(-3) % parasitemia, and its specificity was 100 %. The results of the study suggest that mPCR represents a simple, efficient test method as a practical alternative for the rapid detection and identification of Theileria species in small ruminants.

Susceptibility of the tick Haemaphysalis qinghaiensis to isolates of the fungus Metarhizium anisopliae in China.

Haemaphysalis qinghaiensis, a prevalent tick species in China, causes severe economic losses. In this study, we investigated the pathogenicity of six isolates of the fungus Metarhizium anisopliae to engorged female H. qinghaiensis using concentrations of 10(6), 10(7) and 10(8) conidia ml(-1). The results indicated that M.aAT08 and M.aAT13 isolates were highly virulent against the ticks. Metarhizium anisopliae has potential for biocontrol of H. qinghaiensis.

Role of Recognition MicroRNAs in Hemaphysalis longicornis and Theileria orientalis Interactions.

Ticks are an important type of pathogen transmission vector, and pathogens not only cause serious harm to livestock but can also infect humans. Because of the roles that ticks play in disease transmission, reducing tick pathogen infectivity has become increasingly important and requires the identification and characterization of these pathogens and their interaction mechanisms. In this study, we determined the miRNA expression profile of Hemaphysalis longicornis infected with Theileria orientalis, predicted the target genes of miRNAs involved in this infection process, and investigated the role of miRNA target recognition during host-pathogen interactions. The results showed that longipain is a target gene of miR-5309, which was differentially expressed at different developmental stages and in various tissues in the control group. However, the miR-5309 level was reduced in the infection group. Analysis of the interaction between miRNA and the target gene showed that miR-5309 negatively regulated the expression of the longipain protein during the infection of H. longicornis with T. orientalis. To verify this inference, we compared longipain with the blocking agent orientalis. In this study, the expression of longipain was upregulated by the inhibition of miR-5309 in ticks, and the ability of the antibody produced by the tick-derived protein to attenuate T. orientalis infection was verified through animal immunity and antigen-antibody binding tests. The results showed that expression of the longipain + GST fusion protein caused the cattle to produce antibodies that could be successfully captured by ticks, and cellular immunity was subsequently activated in the ticks, resulting in a subtractive effect on T. orientalis infection. This research provides ideas for the control of ticks and tickborne diseases and a research basis for studying the mechanism underlying the interaction between ticks and pathogens.