Psoroptes Research Articles

The mitochondrial genomes of sarcoptiform mites: are any transfer RNA genes really lost?

BackgroundMitochondrial (mt) genomes of animals typically contain 37 genes for 13 proteins, two ribosomal RNA (rRNA) genes and 22 transfer RNA (tRNA) genes. In sarcoptiform mites, the entire set of mt tRNA genes is present in Aleuroglyphus ovatus, Caloglyphus berlesei, Dermatophagoides farinae, D. pteronyssinus, Histiostoma blomquisti and Psoroptes cuniculi. Loss of 16 mt tRNA genes, however, was reported in Steganacarus magnus; loss of 2–3 tRNA genes was reported in Tyrophagus longior, T. putrescentiae and Sarcoptes scabiei. Nevertheless, convincing evidence for mt gene loss is lacking in these mites.ResultsWe sequenced the mitochondrial genomes of two sarcoptiform mites, Histiostoma feroniarum (13,896 bp) and Rhizoglyphus robini (14,244 bp). Using tRNAScan and ARWEN programs, we identified 16 and 17 tRNA genes in the mt genomes of H. feroniarum and R. robini, respectively. The other six mt tRNA genes in H. feroniarum and five mt tRNA genes in R. robini can only be identified manually by sequence comparison when alternative anticodons are considered. We applied this manual approach to other mites that were reported previously to have lost mt tRNA genes. We were able to identify all of the 16 mt tRNA genes that were reported as lost in St. magnus, two of the three mt tRNA genes that were reported as lost in T. longior and T. putrescentiae, and the two mt tRNA genes that were reported as lost in Sa. scabiei. All of the tRNA genes inferred from these manually identified genes have truncation in the arms and mismatches in the stems.ConclusionsOur results reveal very unconventional tRNA structures in sarcoptiform mites and do not support the loss of mt tRNA genes in these mites. The functional implication of the drastic structural changes in these tRNA genes remains to be investigated.

Toxicity of fipronil in rabbits as a therapeutic drug for "Psoroptes cuniculi": A preliminary observation

In the current report, a preliminary observation to study the adverse effects of the broad use acaricides fipronil (FPN) in rabbits infested with Psoroptes cuniculi. Two separate groups (5 rabbits/each) treated topically (poured on at the base of the neck) with fipronil 5%, 1 vial/ 10 kilogram body weight (kg bw) and 1 vial/ 5 kg bw. After FPN spot on application, rabbits in both groups examined microscopically on the 7th, 14th, and 28th day post treatment and the number of live mites (larvae, nymphs, and adults) on each rabbit counted at the end of the experiment (28th day). The results showed that the number of mites in rabbits topically treated with FPN did not show significant decrease, moreover a decrease in both treated rabbits body weight (bw) and in performance observed clearly, with some attendant mortality. In conclusion, this work showed that FPN was with limited efficacy on P. cuniculi and had some undesirable side effects. Further and in-depth studies on FPN toxicity in rabbits and other animals are necessary.

Design, Bioactivity and structure-activity of 3-Arylpropionate Derivatives as Potential High-Efficient Acaricides against Psoroptes Cuniculi

A series of 3-aryl propionic esters and their analogues were designed and evaluated for acaricidal activity in vitro against Psoroptes cuniculi, a mange mite. The structure–activity relationship (SAR) was also discussed. The results showed that 6 compounds possessed the excellent activity (LC50 = 0.17–0.24 mM, LT50 = 1.5–2.9 h), superior to ivermectin (LC50 = 0.28 mM, LT50 = 8.9 h) (P < 0.05), a standard drug. Furthermore, 7 compounds showed the good activity (LC50 = 0.25–0.37 mM, LT50 < 3.9 h), slightly lower or close to that of ivermectin. One compound displayed super-fast acaricidal property, far superior to ivermectin. SAR analysis found that the ester group is vital for the activity and the small steric hindrance adjacent to the ester group is advantageous for the high activity. The <C4 linear alcohol esters can give the higher activity. The substituents on the 3-phenyl ring or replacement of the 3-phenyl with heterocyclic aryl generally decreases the activity. The position of the ester group in the ester chain also influences the activity, where the 3-phenyl propionate and the benzoate had the highest and lowest activity, respectively. Thus, 3-arylpropionates emerged as new and promising high-efficient acaricide candidates.

Application of Sustainable Natural Resources in Agriculture: Acaricidal and Enzyme Inhibitory Activities of Naphthoquinones and Their Analogs against Psoroptes cuniculi

As important secondary plant metabolites, naphthoquinones exhibit a wide range of biological activities. However, their potential as sustainable alternatives to synthetic acaricides has not been studied. This study for the first time investigates the acaricidal activity of naphthoquinones against Psoroptes cuniculi in vitro. Furthermore, the in vivo activity, the skin irritation effects, the cytotoxicity and the inhibitory activities against mite acetylcholinesterase (AChE) and glutathione S-transferase (GST) of the two compounds that displayed the best insecticidal activity in vitro were evaluated. Among fourteen naphthoquinones and their analogs, juglone and plumbagin were observed to possess the strongest acaricidal activities against P. cuniculi with LC50 values of 20.53 ppm and 17.96 ppm, respectively, at 24 h. After three treatments, these two chemicals completely cured naturally infested rabbits in vivo within 15 days, and no skin irritation was found in any of the treated rabbits. Compared to plumbagin, juglone presented no or weak cytotoxicity against HL-7702 cells. Moreover, these two chemicals significantly inhibited AChE and GST activity. These results indicate that juglone has promising toxicity against P. cuniculi, is safe for both humans and animals at certain doses, and could be used as a potential alternative bio-acaricide for controlling the development of psoroptic mange in agricultural applications.

Treatment of sheep scab in the UK: preventing the spread of resistant mites

Sheep scab is a parasitic allergic dermatitis that affects sheep worldwide and is caused by the non-burrowing mite, Psoroptes ovis . It has serious welfare implications for animals affected (Fig...

The prevalence and distribution of sheep scab in Wales: a farmer questionnaire survey.

Outbreaks of ovine psoroptic mange in the U.K. have increased 100-fold since its deregulation in 1992, with the highest prevalence in Wales, a region of high sheep density. A cross-sectional, retrospective, questionnaire-based survey of 7500 members of the association of Welsh lamb and beef farmers [Welsh Lamb and Beef Producers Ltd (WLBP)] was used to investigate the prevalence and distribution of sheep scab in this region in 2015. The survey was completed by 14.0% (n = 972) of potential respondents. Scab outbreaks were reported on 15.8% (n = 154) of farms in 2015. However, 29.0% (n = 282) of farms reported at least one scab outbreak and 2.4% (n = 23) of farms had experienced between six and 10 outbreaks in the previous 10 years. Most outbreaks occurred during September-January (83.0%, n = 150), and were clustered around Brecon (mid-Wales) and Bangor (North Wales). Farmers who used common grazing were significantly more likely to report scab outbreaks in the previous 10 years than farmers who did not. No quarantine procedures for sheep bought in were used by 29.0% (n = 262) of farmers. Future research should be directed towards the development of localized management programmes, with a particular focus on areas of common grazing.

First evidence of resistance to macrocyclic lactones in Psoroptes ovis sheep scab mites in the UK

Ovine psoroptic mange (sheep scab) is an infection of substantial economic and animal welfare concern in the UK. Its prevalence has increased rapidly over the last 20 years and management...

Improving agricultural production of domestic rabbits in Serbia by follow-up study of their parasitic infections.

A study was made on the prevalence of some parasitic infections appearing in domestic rabbits obtained from individual breeders in Serbia in order to improve the agricultural production of these animals. Aside from economic reasons (meat production and reproduction) rabbits are bred for the research purposes, and races are kept as household pets. For these reasons, among others, it is important to gain knowledge of medical culprits including causes of parasitic diseases that compromise their health, well-being and cause economic losses. This parasitological research was conducted in the period from 2010 to 2015 in 8 epidemiological regions of Serbia, on 433 rabbits as representative samples of different races (154 individuals up to 1 years of age and 279 individuals older than 5). Out of the total number of examined rabbits parasitic infections were established in 82.68% of animals. We detected 3 species of endoparasites (Eimeria spp., Trichostrongylus spp., and Passalurus ambiguus) and 3 species of ectoparasites (Scabies from genera Sarcoptes, Psoroptes and Notoedres). In "kits" (small rabbits) coccidiosis was the most prevalent disease (50.65%), while in older animals trichostrongilidosis was common (39.07%). The most represented scabies infection was with the species Psoroptes cuniculi (12.01%). Aiming at better control on the health of rabbits, there is a growing need for continual monitoring of parasitic infections including appropriate diagnosis, application efficient therapeutic protocols and control measures.

Bioactivity and structure–activity relationship of cinnamic acid derivatives and its heteroaromatic ring analogues as potential high-efficient acaricides against Psoroptes cuniculi

A series of cinnamic acid derivatives and its heteroaromatic ring analogues were synthesized and evaluated for acaricidal activity in vitro against Psoroptes cuniculi, a mange mite. Among them, eight compounds showed the higher activity with median lethal concentrations (LC50) of 0.36–1.07mM (60.4–192.1µg/mL) and great potential for the development of novel acaricidal agent. Compound 40 showed both the lowest LC50 value of 0.36mM (60.4µg/mL) and the smallest median lethal time (LT50) of 2.6h at 4.5mM, comparable with ivermectin [LC50=0.28mM (247.4µg/mL), LT50=8.9h], an acaricidal drug standard. SAR analysis showed that the carbonyl group is crucial for the activity. The type and chain length of the alkoxy in the ester moiety and the steric hindrance near the ester group significantly influence the activity. The esters were more active than the corresponding thiol esters, amides, ketones or acids. Replacement of the phenyl group of cinnamic esters with α-pyridyl or α-furanyl significantly increase the activity. Thus, a series of cinnamic esters and its heteroaromatic ring analogues with excellent acaricidal activity emerged.

Therapeutic management of Dermatosis in Rabbits

Psoroptic mange occurs in the ears of domestic and wild animals, particularly in the ears of rabbits. It is caused by Psoroptes cuniculi (Darzi and Samuel, 2001, Bhardwaj et al., 2012). It is a common parasitic disease problem in both pet and commercial rabbits. These ear mites do not burrow, they feed on skin tissue, which irritates the skin and causes lesions and subsequently produces the scabs which protect the mites from the environment and shield them from removal by the animal when it scratches. In India with hot and humid climate, the incidence of the skin infections especially mange in the rabbits is very high (Aulakh et al ., 2003). Mange leads to listlessness, anorexia, emaciation complication of middle or inner ear, wry neck and deaths resulting in considerable economic losses (Ravindran et al ., 2000). Ivermectin is used as a broad spectrum parasiticide in domestic animals and is also recommended for treatment of ear mange in rabbits. Several studies have been conducted on the dose levels and duration of parentral administration of ivermectin in rabbits affected with ear mange (Fajimi et al ., 2002, Jana et al .,2004, Hansen et al. ,2005, Panigrahi and Gupta, 2013). The present study was carried out to evaluate the effect of parentral administration followed by oral administration of ivermectin against Psoroptic

In vitro acaricidal activity of extracts from 16 traditional Chinese medicines against Psoroptes ovis var. cuniculi

ABSTRACTThe in vitro acaricidal activities of 16 different traditional Chinese medicines against Psoroptes ovis var. cuniculi were evaluated using extracts prepared by water decocting and ethanol thermal circumfluence. The decoction extracts of Leonurus japonicus, Euphorbia lunulata, and Pyrethrum carneum had strong toxicities towards mites, as did mixtures of the aqueous extracts of L. japonicus and E. lunulata. The mixture containing aqueous extracts of L. japonicus and E. lunulata in a 1:1 ratio killed all mites within 6 h, and mixtures with ratios of 1:0 and 0.5:1 also exhibited strong toxicity. The results indicated that L. japonicus and E. lunulata contain potent acaricidal ingredients.

Evaluation of Oxidative Stress in Sheep Infected with Psoroptes Ovis using Total Antioxidant Capacity, Total Oxidant Status, and Malondialdehyde Level.

IntroductionThe study aimed at evaluating oxidative stress using malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) markers in sheep naturally infected with Psoroptes ovis(Acari).Material and MethodsThe study was performed on 40 sheep divided into two equal groups: a healthy group (group I) and a group naturally infected with Psoroptes ovis (group II). The sera were obtained by centrifuging blood samples collected from the vena jugularis and serum MDA level changes in the samples were measured spectrophotometrically. Commercially available test kits were used for the measurement of TAC and TOS levels. The percentage ratio of TOS level to TAC level was accepted as OSI.ResultsThe serum malondialdehyde, total oxidant status levels, and oxidative stress index increased significantly (P < 0.01) in group II, while the serum total antioxidant capacity levels decreased significantly (P < 0.01) in this group. Negative correlations between total antioxidant capacity and total oxidant status and total antioxidant capacity and malondialdehyde, and a positive correlation between total oxidant status and malondialdehyde were found in infected sheep.ConclusionThe obtained results indicated the relationship between oxidant/antioxidant imbalance and Psoroptes ovis infection in sheep. Their MDA, TAC, TOS, and OSI markers may be used to determine the oxidative stress in natural infections with Psoroptes ovis.

Der f 35: An MD-2-like house dust mite allergen that cross-reacts with Der f 2 and Pso o 2.

Dermatophagoides farinae is a source of airborne house dust mite (HDM) allergens. We elucidated IgE-reactive allergens from D.farinae by two-dimensional immunoblotting-based allergenome analysis, and identified one new allergen, named Der f 35, that possesses IgE-binding capacity comparable to that of Der f 2. The aim of this study was to clarify the allergenic capacity of new HDM allergen Der f 35. We cloned der f 35 from D.farinae mRNA and produced recombinant Der f 35 in Escherichia coli. The IgE-binding capacity of Der f 35 and its cross-reactivity with group 2 allergens from D.farinae and Psoroptes ovis were determined by enzyme-linked immunosorbent assay (ELISA) and ELISA inhibition assays, respectively. The deduced amino acid sequence for der f 35, which possesses the MD-2-related lipid-recognition domain, showed higher identity with group 2 allergens from P.ovis (61.5%) and Blomia tropicalis (50.7%) than with Der f 2 (40.8%). Der f 35 showed IgE-binding frequencies of 77.5% (31/40) for the native form upon allergenome analysis and 51.4% (18/35) for recombinant structure by ELISA. Der f 35 showed cross-reactivity with Der f 2 and Pso o 2 in reaction with HDM-allergic patients' IgE by ELISA inhibition assay. Der f 35 is a candidate major allergen from D.farinae, which is more similar to group 2 allergens from sheep scab mite and storage mites. Der f 35 could be responsible for the cross-reactivity among group 2 mite allergens.

PREVALENCE OF MANGE MITES ON SMALL RUMINANTS IN HARAMAYA WEREDA (DISTRICT), EAST HARARGE ZONE, ETHIOPIA

A cross-sectional study was conducted between November 2011 and March 2012 to determine the prevalence of mange mites and to identify the major mite species affecting small ruminants in Haramaya wereda (district), East Harerghe zone, Eastern Ethiopia. A total of 810 animals from both species (384 sheep and 421 goats) were sampled using the formula of [1]. The study showed that the prevalence of mange mite in sheep and goats was 3.34% and 5.94%, respectively. From 197 and 613, young and adult small ruminants examined for mange mites the recorded prevalence rate was 6.09% and 4.61%, respectively whereas among 373 and 437, male and female small ruminants examined for mange mites the prevalence rate of 4.02 and 5.26% was recorded, respectively. The prevalence rate recorded in lowland and midland was 4.22% and 2.77%, respectively. No statistically significant association was observed between the prevalence rate and different species, age and sex of the animals (p&gt;0.05). However, there was statistically significant association between the prevalence rate of mange infestation and agro-ecological zones (p&lt;0.05). The major species of mites identified were sarcoptes spp, psoroptes spp and demodex spp in goat and only psoroptes spp in sheep. From the mange mite species-affecting goats, sarcoptes scabies was the most prevalent species observed on 4.28% of the goats followed by psoroptes ovis (0.95%) and demodex caprae (0.71%). In sheep, the prevalence of the only identified species, psoroptes ovis was 3.34%. Further studies should be done to evaluate risk factors and the seasonal occurrence of mange in small ruminants in the area to devise effective control measure.

The toxicity and the acaricidal mechanism against Psoroptes cuniculi of the methanol extract of Adonis coerulea Maxim

ScopeAdonis coerulea Maxim. is a perennial herbaceous plant that grows in scrub, grassy slope areas, and as traditional medicine it has been used to treat animal acariasis for thousands of years. In this paper, we aimed to study the acute toxicity and cytotoxicity of the methanol extract of A. coerulea (MEAC) in vivo and in vitro for supporting the clinic uses. The acaricidal activity and the mechanism of action against Psoroptes cuniculi were investigated. ResultsThe results showed that isoorientin, luteolin and apigenin were the primary compounds in MEAC. The toxicity test showed that median lethal dose (LD50) and the 50% inhibitory concentration (IC50) of MEAC were estimated to be more than 5000mg/kg in mice in vivo and more than 50mg/ml against RAW 264.7 and GM00637 cells in the 3-(4, 5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide (MTT) test. After culturing with MEAC, the activities of superoxide dismutase (SOD), catalase (CAT), malonyldialdehyde (MDA), glutathione-S-transferase (GST), acetylcholinesterase (AChE) and Na+-K+-ATPase of mites were evaluated. Compared with the control group, SOD activity of MEAC-treated group of mites was inhibited, and CAT activity was activated at the preliminary phase but was gradually inhibited over the period of incubation. MDA content reached a peak at 6h and then gradually decreased. However, GST activity in the mites was activated in a dose- and time-dependent manner. AChE and Na+-K+-ATPase activities related to neural conduction, vital functions and the transmembrane ion gradient of the mites were inhibited. ConclusionMEAC is safe in the given doses in both the in vitro and the in vivo tests, can be applied in the clinic and it had good acaricidal activity. The extension of the incubation time in the mites led to dynamic disequilibrium between the production and clearing of superoxide anions, a disruption of the energy metabolism and the transmembrane ion gradient, and the inhibition of motor function. These factors may have resulted in mite death.

Therapeutic use of Bacillus thuringiensis in the treatment of psoroptic mange in naturally infested New Zealand rabbits

Bacillus thuringiensis is a bacteria known for its bioinsecticidal toxins and it has been proposed as an alternative in the treatment of several parasites that infect domestic animals (helminths, ticks, mites). In this work, we evaluated the clinical efficiency of the Bacillus thuringiensis GP532 strain in the treatment of six rabbits naturally infested with the P. cuniculi mite. GP532 extract (10mg/ml) was applied by aspersion in both pinna, with a second application after seven days, and the therapeutic effect was measured in both qualitative and quantitative manner. GP532 application resulted in a decreased infestation rate, which was observed as early as 3days post-treatment. At day 14, a decrease from 4.66±0.61 to 0.50±0.10 in the left pinna and from 1.66±0.21 to 0.66±0.16 (P<0.05) in the right pinna was observed. This response was comparable to the commercial drug Ivermectin, which induced a decreased infestation rate from 4.00±0.51 to 0.16±0.10 in the left pinna and from 4.66±0.80 to 0.25±0.11 in the right pinna (P<0.05). At day 30 post-treatment, GP532 decreased the total infested area by 76.80±16.06%, whereas Ivermectin resulted in a 97.41±0.99% decrease. Neither treatment produced irritation or macroscopic lesions. Our results show that the B. thuringiensis GP532 strain has a therapeutic potential in the treatment of psoroptic mange in rabbits.

Acaricidal activities of the essential oil from Rhododendron nivale Hook. f. and its main compund, δ-cadinene against Psoroptes cuniculi

In this paper, the acaricidal activities of Rhododendron nivale Hook. f. and its main compound, δ-cadinene were investigated, and the chemical composition of the essential oil was analyzed. The results showed that among aqueous, 70% ethanols, acetic ether, chloroform, petroleum ether and essential oil extracts from the shoots and leaves, the essential oil showed the best in vitro acaricidal activity against adult P. cuniculi, which occurred in a concentration- and time-dependent manner. The median lethal time (LT50) values of four concentrations (33.33–4.17mg/ml) of the essential oil ranged from 1.476 to 25.900h, respectively. After the treatment of P. cuniculi with the essential oil and ivermectin, infected rabbits were free of scabs or secretions in the ear canal by day 20. Then, the percent yield of essential oil from the leaves and shoots was 2.45% (w/w), which includes 50 compounds. The primary component identified was terpenes, and among of compounds identified from the essential oil of R. nivale the highest relative content was δ-cadinene, which also presented the marked acaricidal activity against Psoroptes cuniculi in vitro. These findings provide evidence for the use of acaricides as a traditional medicine and indicate that the essential oil and δ-cadinene could be used to control mites in livestock.

Prevalence, treatment and management of health conditions in pet rabbits presented to the Veterinary Teaching Hospital (VTH), University of Peradeniya

Forty five pet rabbits of different breeds with various clinical conditions were presented to the VTH from January 2014 to March 2016 reflecting an emerging trend in companion animal ownership and health concerns. Of these cases, Psoroptic mange was the commonest disease condition while traumatic injuries (26.7%) including dog bite wounds, fractures, eye conditions were regularly encountered. Chemical trauma and infectious diseases (17.8%) namely, ulcerative pododermatitis, respiratory tract and urinary tract infections; miscellaneous cases such as floppy rabbit syndrome, heat stress, nutritional deficiency and prolapsed vagina were also presented. The objective of this communication is to make the veterinary practitioners aware of the common health conditions encountered in pet rabbits and how those were treated and managed.

Efficacy of oral doramectin as treatment for Psoroptes ovis and Leporacarus gibbus in naturally infested rabbits

ABSTRACT: The present study evaluated the efficacy of a single oral dose of doramectin in the control of Psoroptes ovis and Leporacarus gibbus in naturally infested rabbits. Sixteen adult rabbits were selected and distributed in two experimental groups. The treated group received 200 μg/Kg of oral doramectin and the control group received the same volume of saline solution. The diagnosis of the mites was made with a stereoscopic microscope. Hairs from the dorsal part of the neck, lumbar right, lumbar left, ventral side of the tail and ventral abdomen were evaluated for L. gibbus, and ear wax evaluated for P. ovis. The evaluation of the efficiency and the clinical assessment of the lesions was made in days 0, +3, +7, +14, +21, +28, and +35 after treatment. An efficacy of 75% and 87,5% was observed for L. gibbus in days +3 and +7 after treatment, an efficacy of 100% was observed in days +14, + 21, +28 e +35. An efficacy of 100% for the control of P. ovis was observed following day +7. The clinical lesion score of the control group remained unaltered, except for one animal which conditions worsened during experimentation. In the treated group animals, regression of the lesions was observed following day +3, and on day +21 no signal of infestation by P. ovis was present. None of the animals from the treated group presented secondary collateral effects caused by the doramectin, which proved itself as an optimal alternative for mite control in naturally infested rabbits.

Biochemical changes investigated by psoroptic mange infestation in buffaloes

The present study was executed on fifty buffaloes ( Bubalusbubalus ), aged 1-3years, suffering from signs of pruritus and alopecia throughout the perio d from January to December 2015. Upon parasitological enquiry, they were proved to be inf ested by Psoroptes species. The changes in the sero- biochemical parameters were compared in two groups, infested group and non infested healthy group, each of 30 buffaloes. The following parameters were assessed: serumtotal protein (TP), serum albumin (ALB), blood urea nitrogen (BUN), creatinine levels , serum enzymatic activities levels as glutamic-- pyruvic transaminase (GPT ), glutamic oxaloacetic t ransaminase (GOT), alkaline phosphastase (ALP), and lactate dehydrogenase (LDH), Oxidative and anti oxidative biomarkers as malondialdehyde (MDA), Glutathione S-transferase (GST), superoxide dismuta se (SOD) and catalase (CAT), inflamatory parameters as C- reactive protein (CRP), pro inflam matory cytokines (IL6) and tumor necrosis factor (TNF). The results concluded a significant differen ce in the serum constituents (P<0.05) between the infested buffaloes and the non-infestedones.